Search results for: investigation
3848 Geographical Information System-Based Approach for Vertical Takeoff and Landing Takeoff and Landing Site Selection
Authors: Chamnan Kumsap, Somsarit Sinnung, Suriyawate Boonthalarath, Teeranai Srithamarong
Abstract:
This research paper addresses the GIS analysis approach to the investigation of suitable sites for a vertical takeoff and landing drone. The study manipulated GIS and terrain layers into a proper input before the spatial analysis that included slope, reclassify, classify, and buffer was applied to the individual layers. The output layers were weighted, and multi-criteria analyzed before those patches failing to comply with filtering out criteria were discarded. Field survey for each suitable candidate site was conducted to cross-check the proposed approach with the real world. Conclusion was extracted for the VTOL takeoff and landing sites, and discussion was provided with further study being suggested on the mission simulation of selected takeoff and landing sites.Keywords: GIS approach, site selection, VTOL, takeoff and landing
Procedia PDF Downloads 1043847 Investigation on the stability of rock slopes subjected to tension cracks via limit analysis
Authors: Weigao. Wu, Stefano. Utili
Abstract:
Based on the kinematic approach of limit analysis, a full set of upper bound solutions for the stability of homogeneous rock slopes subjected to tension cracks are obtained. The generalized Hoek-Brown failure criterion is employed to describe the non-linear strength envelope of rocks. In this paper, critical failure mechanisms are determined for cracks of known depth but unspecified location, cracks of known location but unknown depth, and cracks of unspecified location and depth. It is shown that there is a nearly up to 50% drop in terms of the stability factors for the rock slopes intersected by a tension crack compared with intact ones. Tables and charts of solutions in dimensionless forms are presented for ease of use by practitioners.Keywords: Hoek-Brown failure criterion, limit analysis, rock slope, tension cracks
Procedia PDF Downloads 3443846 Investigation of Different Control Stratgies for UPFC Decoupled Model and the Impact of Location on Control Parameters
Authors: S. A. Al-Qallaf, S. A. Al-Mawsawi, A. Haider
Abstract:
In order to evaluate the performance of a unified power flow controller (UPFC), mathematical models for steady state and dynamic analysis are to be developed. The steady state model is mainly concerned with the incorporation of the UPFC in load flow studies. Several load flow models for UPFC have been introduced in literature, and one of the most reliable models is the decoupled UPFC model. In spite of UPFC decoupled load flow model simplicity, it is more robust compared to other UPFC load flow models and it contains unique capabilities. Some shortcoming such as additional set of nonlinear equations are to be solved separately after the load flow solution is obtained. The aim of this study is to investigate the different control strategies that can be realized in the decoupled load flow model (individual control and combined control), and the impact of the location of the UPFC in the network on its control parameters.Keywords: UPFC, decoupled model, load flow, control parameters
Procedia PDF Downloads 5553845 Unsupervised Learning with Self-Organizing Maps for Named Entity Recognition in the CONLL2003 Dataset
Authors: Assel Jaxylykova, Alexnder Pak
Abstract:
This study utilized a Self-Organizing Map (SOM) for unsupervised learning on the CONLL-2003 dataset for Named Entity Recognition (NER). The process involved encoding words into 300-dimensional vectors using FastText. These vectors were input into a SOM grid, where training adjusted node weights to minimize distances. The SOM provided a topological representation for identifying and clustering named entities, demonstrating its efficacy without labeled examples. Results showed an F1-measure of 0.86, highlighting SOM's viability. Although some methods achieve higher F1 measures, SOM eliminates the need for labeled data, offering a scalable and efficient alternative. The SOM's ability to uncover hidden patterns provides insights that could enhance existing supervised methods. Further investigation into potential limitations and optimization strategies is suggested to maximize benefits.Keywords: named entity recognition, natural language processing, self-organizing map, CONLL-2003, semantics
Procedia PDF Downloads 483844 Organizational Change in the FBI after 9/11: An Institutional Theoretical Analysis
Authors: Ben D. Atkins
Abstract:
This study will examine the impact of September 11, 2001, terrorist attacks on the organizational development of American federal law enforcement through focusing on the Federal Bureau of Investigation. Content analysis of discourse in a federal law enforcement practitioner publication along with official FBI statements will be used to gain a better understanding of FBI organizational changes that have taken place since the events of September 11, 2001. Analysis of content trends in the FBI Law Enforcement Bulletin and public discourse of FBI officials from 1999 to 2005 indicate that, in addition to structural changes, the bureau has also undergone a variety of cultural changes. The results offer some support for the institutional theoretical perspective, suggesting that post-9/11 organizational changes such as new mission priorities and the establishment of new branches were partially initiated due to a variety external pressures, which lends support for coercive isomorphism. Furthermore, structural changes are discussed in relation to the attainment and maintenance of organizational legitimacy.Keywords: institutional theory, organizational theory, law enforcement, public administration
Procedia PDF Downloads 2403843 Numerical Investigation of Slot Die Coating Based on VOF Method
Authors: Zhidi Lei, Xixi Cai, Jue Ding, Peifen Weng, Xiaowei Li
Abstract:
In the process of preparing thin films by chemical solution method, the uniformity of gel coating has a great influence on the subsequent film thickness. Based on a coating device, the research tracks the interface development of gas-liquid flow by volume of fluid method (VOF). The effects of fluid viscosity and wall wetting property for the shape and position of the coating window are discussed in the process of slot die coating. The result shows that downstream contact lines gets closer to the corner with the increase of fluid viscosity. When the viscosity increases from 0.2Pa∙s to 0.3Pa∙s, 18.2% of the vortex region area will be reduced. With the static contact angle of upper die head surface (θ_sd) increasing, X_u decreased gradually which cause the instability changes of upstream surface. Also, θ_sd increasing brings the reduction of vortex region.Keywords: film growth, vortex, VOF, slot die coating
Procedia PDF Downloads 3733842 Attitudes of Saudi Students Attending the English Programmes of the Royal Commission for Jubail and Yanbu toward Using Computer-Assisted Language Learning
Authors: Sultan Ahmed Arishi
Abstract:
The objective of the study was to investigate the attitude of the Saudi students attending the English Language programmes of the Royal Commission for Jubail towards using CALL, as well as to discover whether computer-assisted teaching is useful and valuable for students in learning English. Data were collected with the help of interviews and survey questionnaires. The outcomes of the investigation showed that students had a positive attitude towards CALL. Moreover, the listening skills of the students had the most substantial effect on students learning English through CALL. Unexpectedly, the teaching staff, equipment, curriculum, or even a student's poor English background was a distinct barrier that attributed to any weaknesses of using CALL, or in other words, all these factors were of a similar attitude.Keywords: CALL, teaching aids, teaching technology, teaching English with technology, teaching English in Saudi Arabia
Procedia PDF Downloads 1463841 Mixed Frequency Excitation of an Electrostatically Actuated Resonator
Authors: Abdallah H. Ramini, Alwathiqbellah I. Ibrahim, Mohammad I. Younis
Abstract:
We investigate experimentally and theoretically the dynamics of a capacitive resonator under mixed frequency excitation of two AC harmonic signals. The resonator is composed of a proof mass suspended by two cantilever beams. Experimental measurements are conducted using a laser Doppler Vibrometer to reveal the interesting dynamics of the system when subjected to two-source excitation. A nonlinear single-degree-of-freedom model is used for the theoretical investigation. The results reveal combination resonances of additive and subtractive type, which are shown to be promising to increase the bandwidth of the resonator near primary resonance frequency. Our results also demonstrate the ability to shift the combination resonances to much lower or much higher frequency ranges. We also demonstrate the dynamic pull-in instability under mixed frequency excitation.Keywords: electrostatically actuated resonator, multi-frequency excitation, nonlinear dynamics, AC harmonic signals
Procedia PDF Downloads 6223840 Teachers of the Pandemic: Retention, Resilience, and Training
Authors: Theoni Soublis
Abstract:
The COVID-19 pandemic created a severe interruption in teaching and learning in K-12 schools. It is essential that educational researchers, teachers, and administrators understand the long term effects that COVID-19 had on a variety of stakeholders in education. This investigation aims to analyze the research since the beginning of the pandemic that focuses specifically on teacher retention, resilience, and training. The results of this investigation will help to inform future research in order to better understand how the institution of education can continue to be prepared and to better prepare for future significant shifts in the modalities of instruction. The results of this analysis will directly impact the field of education as it will broaden the scope of understanding regarding how COVID- 19 impacted teaching and learning. The themes that will emerge from the data analysis will directly inform policy makers, administrators, and researchers about how to best implement training and curriculum design in order to support teacher effectiveness this in the classroom. Educational researchers have written about how teacher morale plummeted and how many teachers reported early burnout and higher stress levels. Teachers’ stress and anxiety soared during the COVID-19 pandemic, but so has their resilience and dedication to the field of education. This research aims to understand how public-school teachers overcame teaching obstacles presented to them during COVID-19. Research has been conducted to identify a variety of information regarding the impact the pandemic has had on K-12 teachers, students, and families. This research aims to understand how teachers continued to pursue their teaching objectives without significant training of effective online instruction methods. Not many educators even heard of the video conferencing platform Zoom before the spring of 2020. Researchers are interested in understanding how teachers used their expertise, prior knowledge, and training to institute immediate and effective online learning environments, what types of relationships did teachers build with students while teaching 100% remotely, and how did relationships change with students while teaching remotely? Furthermore, did the teacher-student relationship propel teacher resolve to be successful while teaching during a pandemic. Recent world events have significantly impacted the field of public-school teaching. The pandemic forced teachers to shift their paradigm about how to maintain high academic expectations, meet state curriculum standards, and assess students learning gains to make data-informed decisions while simultaneously adapting modes of instruction through multiple outlets with little to no training on remote, synchronous, asynchronous, virtual, and hybrid teaching. While it would be very interesting to study how teaching positively impacted students learning during the pandemic, I am more interested in understanding how teaches stayed the course and maintained their mental health while dealing with the stress and pressure of teaching during COVID-19.Keywords: teacher retention, COVID-19, teacher education, teacher moral
Procedia PDF Downloads 853839 Synchrotron X-Ray Based Investigation of As and Fe Bonding Environment in Collard Green Tissue Samples at Different Growth Stages
Authors: Sunil Dehipawala, Aregama Sirisumana, stephan Smith, P. Schneider, G. Tremberger Jr, D. Lieberman, Todd Holden, T. Cheung
Abstract:
The arsenic and iron environments in different growth stages have been studied with EXAFS and XANES using Brookhaven Synchrotron Light Source. Collard Greens plants were grown and tissue samples were harvested. The project studied the EXAFS and XANES of tissue samples using As and Fe K-edges. The Fe absorption and the Fourier transform bond length information were used as a control comparison. The Fourier transform of the XAFS data revealed the coexistence of As (III) and As (V) in the As bonding environment inside the studied plant tissue samples, although the soil only had As (III). The data suggests that Collard Greens has a novel pathway to handle arsenic absorption in soil.Keywords: EXAFS, fourier transform, metalloproteins, XANES
Procedia PDF Downloads 3283838 Using Focus Group Method to Identify Citizen Requirements to Saudi Mobile Government Services
Authors: S. Alotaibi, D. Roussinov
Abstract:
Mobile government services implementation faces several challenges in developing countries. This paper studies some of those challenges in the context of Saudi Arabia. The study aims to investigate factors affecting m-government acceptance in Saudi Arabia, including ease of use, usefulness, service quality, trust, intention to use and users’ satisfaction. Our investigation will help in integrating the m-government services in citizens’ everyday life. We collected and analyzed our data from focus groups. These focus groups are from King Saud University and Imam Muhammed Bin Saud University, so the samples size are five and seven participants, respectively. We found that there are some factors to identifying citizen requirements to Saudi mobile government services. These services should be easy to use and not require too much effort. Also, these services must be fully trusted.Keywords: e-government, m-government, focus group, Saudi mobile government services
Procedia PDF Downloads 2973837 Investigation of the Brake Force Distribution in Passenger Cars
Authors: Boukhris Lahouari, Bouchetara Mostefa
Abstract:
The active safety of a vehicle is mainly influenced by the properties of the installed braking system. With the increase in road traffic density and travel speeds, increasingly stringent requirements are placed on the vehicle's behaviour during braking. The achievable decelerations are limited by the physical aspect characterized by the coefficient of friction between the tires and the ground. As a result, it follows that an optimized distribution of braking forces becomes necessary for a better use of friction coefficients. This objective could only be achieved if sufficient knowledge is available on the theory of vehicle dynamics during braking and on current standards for the approval of braking systems. This will facilitate the development of a braking force calculation algorithm that will enable an optimized distribution of braking forces to be achieved. Operating safety is conditioned by the requirements of efficiency, progressiveness, regularity or fidelity of a braking system without obviously neglecting the recommendations imposed by the legislator.Keywords: brake force distribution, distribution diagram, friction coefficient, brake by wire
Procedia PDF Downloads 793836 Exploring the Nature and Meaning of Theory in the Field of Neuroeducation Studies
Authors: Ali Nouri
Abstract:
Neuroeducation is one of the most exciting research fields which is continually evolving. However, there is a need to develop its theoretical bases in connection to practice. The present paper is a starting attempt in this regard to provide a space from which to think about neuroeducational theory and invoke more investigation in this area. Accordingly, a comprehensive theory of neuroeducation could be defined as grouping or clustering of concepts and propositions that describe and explain the nature of human learning to provide valid interpretations and implications useful for educational practice in relation to philosophical aspects or values. Whereas it should be originated from the philosophical foundations of the field and explain its normative significance, it needs to be testable in terms of rigorous evidence to fundamentally advance contemporary educational policy and practice. There is thus pragmatically a need to include a course on neuroeducational theory into the curriculum of the field. In addition, there is a need to articulate and disseminate considerable discussion over the subject within professional journals and academic societies.Keywords: neuroeducation studies, neuroeducational theory, theory building, neuroeducation research
Procedia PDF Downloads 4483835 Quantum Algebra from Generalized Q-Algebra
Authors: Muna Tabuni
Abstract:
The paper contains an investigation of the notion of Q algebras. A brief introduction to quantum mechanics is given, in that systems the state defined by a vector in a complex vector space H which have Hermitian inner product property. H may be finite or infinite-dimensional. In quantum mechanics, operators must be hermitian. These facts are saved by Lie algebra operators but not by those of quantum algebras. A Hilbert space H consists of a set of vectors and a set of scalars. Lie group is a differentiable topological space with group laws given by differentiable maps. A Lie algebra has been introduced. Q-algebra has been defined. A brief introduction to BCI-algebra is given. A BCI sub algebra is introduced. A brief introduction to BCK=BCH-algebra is given. Every BCI-algebra is a BCH-algebra. Homomorphism maps meanings are introduced. Homomorphism maps between two BCK algebras are defined. The mathematical formulations of quantum mechanics can be expressed using the theory of unitary group representations. A generalization of Q algebras has been introduced, and their properties have been considered. The Q- quantum algebra has been studied, and various examples have been given.Keywords: Q-algebras, BCI, BCK, BCH-algebra, quantum mechanics
Procedia PDF Downloads 1993834 Investigation of Microstructure, Mechanical Properties and Anti-Corrosive Behavior of Al2O3/Cr2O3 Nanocomposite on Zn Rich Bath
Authors: N. Malatji, A. P. I. Popoola
Abstract:
Zn-Al2O3 and Cr2O3 nanocomposite coatings were successfully produced by electrodeposition technique from chloride acidic bath. Particle loading of Al2O3 (50nm) particles were varied from 5-10 g/L and for Cr2O3(100nm) was 10-20 g/L. Scanning electron microscope (SEM) affixed with energy dispersive spectrometry was used to study the surface morphology and content of the nanoparticles incorporated into the coatings. Microhardness, thermal stability, wear and corrosion behavior of the coatings were also evaluated to study the effect of these nanoparticles on these properties. Zn-Al2O3 nanocomposite was found to exhibit good surface properties especially corrosion resistance. On the other side, Cr2O3 incorporation resulted in the improvement of only mechanical properties. Therefore, Zn-Al2O3 proved to be a better coating for most industrial applications where both chemical and mechanical properties are required.Keywords: electrodeposition, nanocomposite coatings, corrosion, thermal stability, tribology
Procedia PDF Downloads 3893833 Heat Transfer and Friction Factor Study for Triangular Duct Solar Air Heater Having Discrete V-Shaped Ribs
Authors: Varun Goel
Abstract:
Solar energy is a good option among renewable energy resources due to its easy availability and abundance. The simplest and most efficient way to utilize solar energy is to convert it into thermal energy and this can be done with the help of solar collectors. The thermal performance of such collectors is poor due to less heat transfer from the collector surface to air. In this work, experimental investigations of single pass solar air heater having triangular duct and provided with roughness element on the underside of the absorber plate. V-shaped ribs are used for investigation having three different values of relative roughness pitch (p/e) ranges from 4-16 for a fixed value of angle of attack (α), relative roughness height (e/Dh) and a relative gap distance (d/x) values are 60°, 0.044 and 0.60 respectively. Result shows that considerable augmentation in heat transfer has been obtained by providing roughness.Keywords: artificial roughness, solar air heater, triangular duct, V-shaped ribs
Procedia PDF Downloads 4523832 Traditional Ecological Knowledge System as Climate Change Adaptation Strategies for Mountain Community of Tangkhul Tribe in Northeast India
Authors: Tuisem Shimrah
Abstract:
One general agreement on climate change is that its causes may be local but the effects are global. Indigenous people are subscribed to “low-carbon” traditional ways of life and as such they have contributed little to causes of climate change. On the contrary they are the most adversely affected by climate change due to their dependence on surrounding rich biological wealth as a source of their livelihood, health care, entertainment and cultural activities This paper deals with the results of the investigation of various adaptation strategies adopted to combat climate change by traditional community. The result shows effective ways of application of traditional knowledge and wisdom applied by Tangkhul traditional community at local and community level in remote areas in Northeast India. Four adaptation measures are being presented in this paper.Keywords: adaptation, climate change, Northeast India, Tangkhul, traditional community
Procedia PDF Downloads 2783831 A Systematic Review of Ethical Leadership in Tourism and Hospitality Settings
Authors: Majd Megheirkouni
Abstract:
The aim of this study is to identify empirical studies that explore and investigate ethical leadership in order to assess and synthesize its impacts and outcomes. This study seeks to provide an evidence-informed answer to a set of questions on ethical leadership definition in the field of tourism and hospitality, its investigation, and examination, and its outcome. A systematic literature review, using medical science-based methodology, was conducted to synthesize research by reliable means. Four themes were identified from the analysis. These themes are: Ethical leaders’ characteristics, healthy work environment, ethical leadership effectiveness, and the application of ethical leadership across cultures. This study provides the potential to move hospitality and tourism leadership forward and encourage researchers to investigate new research topics. To the best of the author’s knowledge, this is the first systematic review focusing on ethical leadership in tourism and hospitality settings.Keywords: ethical leadership, approach, outcome, tourism, hospitality, systematic review
Procedia PDF Downloads 1003830 Nanofluids and Hybrid Nanofluids: Comparative Study of Mixed Convection in a Round Bottom Flask
Authors: Hicham Salhi
Abstract:
This research project focuses on the numerical investigation of the mixed convection of Hybrid nanofluids in a round bottom flask commonly used in organic chemistry synthesis. The aim of this study is to improve the thermal properties of the reaction medium and enhance the rate of chemical reactions by using hybrid nanofluids. The flat bottom wall of the flask is maintained at a constant high temperature, while the top, left, and right walls are kept at a low temperature. The nanofluids used in this study contain suspended Cu and Al2O3 nanoparticles in pure water. The governing equations are solved numerically using the finite-volume approach and the Boussinesq approximation. The effects of the volume fraction of nanoparticles (φ) ranging from 0% to 5%, the Rayleigh number from 103 to 106, and the type of nanofluid (Cu and Al2O3) on the flow streamlines, isotherm distribution, and Nusselt number are examined in the simulation. The results indicate that the addition of Cu and Al2O3 nanoparticles increases the mean Nusselt number, which improves heat transfer and significantly alters the flow pattern. Moreover, the mean Nusselt number increases with increasing Rayleigh number and volume fraction, with Cu- Al2O3 hybrid nanofluid producing the best results. This research project focuses on the numerical investigation of the mixed convection of Hybrid nanofluids in a round bottom flask commonly used in organic chemistry synthesis. The aim of this study is to improve the thermal properties of the reaction medium and enhance the rate of chemical reactions by using hybrid nanofluids. The flat bottom wall of the flask is maintained at a constant high temperature, while the top, left, and right walls are kept at a low temperature. The nanofluids used in this study contain suspended Cu and Al2O3 nanoparticles in pure water. The governing equations are solved numerically using the finite-volume approach and the Boussinesq approximation. The effects of the volume fraction of nanoparticles (φ) ranging from 0% to 5%, the Rayleigh number from 103 to 106, and the type of nanofluid (Cu and Al2O3) on the flow streamlines, isotherm distribution, and Nusselt number are examined in the simulation. The results indicate that the addition of Cu and Al2O3 nanoparticles increases the mean Nusselt number, which improves heat transfer and significantly alters the flow pattern. Moreover, the mean Nusselt number increases with increasing Rayleigh number and volume fraction, with Cu- Al2O3 hybrid nanofluid producing the best results.Keywords: bottom flask, mixed convection, hybrid nanofluids, numerical simulation
Procedia PDF Downloads 883829 Blood Clot Emulsification via Ultrasonic Thrombolysis Device
Authors: Sun Tao, Lou Liang, Tan Xing Haw Marvin, Gu Yuandong Alex
Abstract:
Patients with blood clots in their brains can experience problems with their vision or speech, seizures and general weakness. To treat blood clots, clinicians presently have two options. The first involves drug therapy to thin the blood and thus reduce the clot. The second choice is to invasively remove the clot using a plastic tube called a catheter. Both approaches carry a high risk of bleeding, and invasive procedures, such as catheter intervention, can also damage the blood vessel wall and cause infection. Ultrasonic treatment as a potential alternative therapy to break down clots is attracting growing interests due to the reduced adverse effects. To demonstrate the concept, in this investigation a microfabricated ultrasonic device was electrically packaged with printed circuit board to treat healthy human blood. The red blood cells could be broken down after 3-hour ultrasonic treatment.Keywords: microfabrication, blood clot, ultrasonic thrombolysis device, ultrasonic device
Procedia PDF Downloads 4503828 Framework for Performance Measure of Super Resolution Imaging
Authors: Varsha Hemant Patil, Swati A. Bhavsar, Abolee H. Patil
Abstract:
Image quality assessment plays an important role in image evaluation. This paper aims to present an investigation of classic techniques in use for image quality assessment, especially for super-resolution imaging. Researchers have contributed a lot towards the development of super-resolution imaging techniques. However, not much attention is paid to the development of metrics for testing the performance of developed techniques. In this paper, the study report of existing image quality measures is given. The paper classifies reviewed approaches according to functionality and suitability for super-resolution imaging. Probable modifications and improvements of these to suit super-resolution imaging are presented. The prime goal of the paper is to provide a comprehensive reference source for researchers working towards super-resolution imaging and suggest a better framework for measuring the performance of super-resolution imaging techniques.Keywords: interpolation, MSE, PSNR, SSIM, super resolution
Procedia PDF Downloads 983827 Numerical Simulation of Filtration Gas Combustion: Front Propagation Velocity
Authors: Yuri Laevsky, Tatyana Nosova
Abstract:
The phenomenon of filtration gas combustion (FGC) had been discovered experimentally at the beginning of 80’s of the previous century. It has a number of important applications in such areas as chemical technologies, fire-explosion safety, energy-saving technologies, oil production. From the physical point of view, FGC may be defined as the propagation of region of gaseous exothermic reaction in chemically inert porous medium, as the gaseous reactants seep into the region of chemical transformation. The movement of the combustion front has different modes, and this investigation is focused on the low-velocity regime. The main characteristic of the process is the velocity of the combustion front propagation. Computation of this characteristic encounters substantial difficulties because of the strong heterogeneity of the process. The mathematical model of FGC is formed by the energy conservation laws for the temperature of the porous medium and the temperature of gas and the mass conservation law for the relative concentration of the reacting component of the gas mixture. In this case the homogenization of the model is performed with the use of the two-temperature approach when at each point of the continuous medium we specify the solid and gas phases with a Newtonian heat exchange between them. The construction of a computational scheme is based on the principles of mixed finite element method with the usage of a regular mesh. The approximation in time is performed by an explicit–implicit difference scheme. Special attention was given to determination of the combustion front propagation velocity. Straight computation of the velocity as grid derivative leads to extremely unstable algorithm. It is worth to note that the term ‘front propagation velocity’ makes sense for settled motion when some analytical formulae linking velocity and equilibrium temperature are correct. The numerical implementation of one of such formulae leading to the stable computation of instantaneous front velocity has been proposed. The algorithm obtained has been applied in subsequent numerical investigation of the FGC process. This way the dependence of the main characteristics of the process on various physical parameters has been studied. In particular, the influence of the combustible gas mixture consumption on the front propagation velocity has been investigated. It also has been reaffirmed numerically that there is an interval of critical values of the interfacial heat transfer coefficient at which a sort of a breakdown occurs from a slow combustion front propagation to a rapid one. Approximate boundaries of such an interval have been calculated for some specific parameters. All the results obtained are in full agreement with both experimental and theoretical data, confirming the adequacy of the model and the algorithm constructed. The presence of stable techniques to calculate the instantaneous velocity of the combustion wave allows considering the semi-Lagrangian approach to the solution of the problem.Keywords: filtration gas combustion, low-velocity regime, mixed finite element method, numerical simulation
Procedia PDF Downloads 3023826 Experimental Procedure of Identifying Ground Type by Downhole Test: A Case Study
Authors: Seyed Abolhassan Naeini, Maedeh Akhavan Tavakkoli
Abstract:
Evaluating the shear wave velocity (V_s) and primary wave velocity (Vₚ) is necessary to identify the ground type of the site. Identifying the soil type based on different codes can affect the dynamic analysis of geotechnical properties. This study aims to separate the underground layers at the project site based on the shear wave and primary wave velocity (Sₚ) in different depths and determine dynamic elastic modulus based on the shear wave velocity. Bandar Anzali is located in a tectonically very active area. Several active faults surround the study site. In this case, a field investigation of downhole testing is conducted as a geophysics method to identify the ground type.Keywords: downhole, geophysics, shear wave velocity, case-study
Procedia PDF Downloads 1403825 The Initiator Matters in Service Co-Recovery: Investigation on Attribution and Satisfaction
Authors: Chia-Ching Tsai
Abstract:
In the literature, the positive effect of service co-recovery has been evidenced, and which customers’ attribution is the key successful factor has also been indicated. There is also literature investigating on initiation of co-recovery for finding out the superior way to co-recovery, and indicating co-recovery initiated by employees causes better effect of co-recovery. This research postulates the consequences of co-recovery by different initiators affect customers’ attribution and the resultant results. Thus, this research uses a 3x2 factorial design to investigate the impact of initiator of co-recovery and consequence of co-recovery on customers’ attribution and post-recovery satisfaction. The results show initiation of co-recovery has a significant influence on internal attribution, and the employee initiator causes the highest internal attribution. The consequences of co-recovery interact with initiators of co-recovery on internal attribution significantly. Moreover, internal attribution significantly affects post-recovery satisfaction.Keywords: service co-recovery, initiation of co-recovery, attribution, post-recovery satisfaction
Procedia PDF Downloads 2633824 The Investigation and Analysis of Village Remains in Jinzhong Prefecture of Shanxi Province, China
Authors: Zhang Yu
Abstract:
Shanxi Province is a province with a long history in China. The historical characteristics of Jinzhong Prefecture in Shaanxi Province are very prominent. This research has done a lot of field research and analysis, and has analyzed a large number of documents. The formation and characteristics of villages in Jinzhong Prefecture are summarized. But the remains of many areas have not been systematically discovered and analyzed. This study found that the reasons for the formation of villages are natural, cultural, traffic and economic reasons. It mainly includes water, mountain, and developed business culture during the Ming and Qing Dynasties. By analyzing the evolution characteristics of each period, the characteristics and remains of the existing villages are explained in detail. These types of relics mainly include courtyards, fortresses, and Exchange shops. This study can provide systematic guidance on the protection of future village remains.Keywords: Jinzhong Prefecture, village, features, remains
Procedia PDF Downloads 1463823 The Heart of Sanctuary Movement and the Ethics of Solidarity
Authors: Irene Ludji
Abstract:
This article discusses the relevance of the sanctuary movement in relation to the idea of solidarity understood through the lens of ethics. There are three parts of this article. First is the investigation on the background of sanctuary movements in the U.S., the UK, and Canada. The repeated theme behind sanctuary movements includes practicing religious traditions, protecting vulnerable life, and challenging the unjust law. Second is the examination of the ethics of solidarity using Thomas D. Williams, who claims it as the extension of responsible love based on respect towards human dignity, and Rebecca Todd Peters, who claims the ethics of solidarity as the transformative ethic rooted in social justice. Third is the analysis of the connection between the central theme of sanctuary movements and the ethics of solidarity. This article concludes that sanctuary movement is indeed a solidarity movement that remains relevant in our world today because the acknowledgment of human dignity, as the basis for solidarity, is vital in transforming an unjust social system that creates the need for a sanctuary in the first place.Keywords: sanctuary movement, solidarity, ethics, U.S., UK, canada
Procedia PDF Downloads 733822 Investigation of Graphene-MoS₂ Nanocomposite as Counter Electrode in Dye-Sensitized Solar Cells
Authors: Mozhgan Hosseinnezhad, Kamaladin Gharanjig, Mehdi Ghahari
Abstract:
Dye-sensitized solar cells are sustainable tool for generating electrical energy using sunlight. To develop this technology, obstacles such as cost and the use of expensive compounds must be overcome. Herein, we employed a MoS₂/graphene composite instead of platinum in the DSSCs. Platinum is an efficient and conventional counter electrode in the preparation of DSSCs, for this purpose, the effect of the presence of platinum electrode was also studied under similar conditions. The prepared nanocomposite product was checked by analysis methods to confirm the correctness of the construction and the desired structure. Finally, the DSSCs were fabricated using MoS₂/graphene composite, and to compare the results, the DSSCs were also prepared using platinum. The results showed that the prepared composite has a similar performance compared to platinum and can replace it.Keywords: efficiency, dye-sensitized solar cell, nano-composite MoS₂, platinum free
Procedia PDF Downloads 643821 Characterization of Thermal Images Due to Aging of H.V Glass Insulators Using Thermographic Scanning
Authors: Nasir A. Al-Geelani, Zulkurnain Abdul-Malek, M. Afendi M. Piah
Abstract:
This research paper investigation is carried out in the laboratory on single units of transmission line glass insulator characterized by different thermal images, which aimed to find out the age of the insulators. The tests were carried out on virgin and aged insulators using the thermography scan. Various samples having different periods of aging 20, 15, and 5 years from a 132 kV transmission line which have exhibited a different degree of corrosion. The second group of insulator samples was relatively mild aged insulators, while the third group was lightly aged; finally, the fourth group was the brand new insulators. The results revealed a strong correlation between the aging and the thermal images captured by the infrared camera. This technique can be used to monitor the aging of high voltage insulators as a precaution to avoid disaster.Keywords: glass insulator, infrared camera, corona diacharge, transmission lines, thermograpy, surface discharge
Procedia PDF Downloads 1603820 Theoretical Investigation of Thermal Properties of Nanofluids with Application to Solar Collector
Authors: Reema Jain
Abstract:
Nanofluids are emergent fluids that exhibit thermal properties superior than that of the conventional fluid. Nanofluids are suspensions of nanoparticles in fluids that show significant enhancement of their properties at modest nanoparticle concentrations. Solar collectors are commonly used in areas such as industries, heating, and cooling for domestic purpose, thermal power plants, solar cooker, automobiles, etc. Performance and efficiency of solar collectors depend upon various factors like collector & receiver material, solar radiation intensity, nature of working fluid, etc. The properties of working fluid which flow through the collectors greatly affects its performance. In this research work, a theoretical effort has been made to enhance the efficiency and improve the performance of solar collector by using Nano fluids instead of conventional fluid like water as working fluid.Keywords: nanofluids, nanoparticles, heat transfer, solar collector
Procedia PDF Downloads 3233819 Convective Boiling of CO₂ in Macro and Mini-Channels
Authors: Adonis Menezes, Julio C. Passos
Abstract:
The present work deals with the theoretical and experimental investigation of the convective boiling of CO₂ in macro and mini-channels. A review of the state of the art of convective boiling studies in mini-channels and conventional channels for operating with CO₂ was carried out, with special attention to the flow patterns and pressure drop maps in single-phase and two-phase flows. To carry out an experimental analysis of the convective boiling of CO₂, a properly instrumented experimental bench was built, which allows a parametric analysis for different thermodynamic conditions, such as mass velocities between 200 and 1300 kg/(m².s), pressures between 20 and 70bar, temperature monitoring at the entrance of the mini-channels, heat flow and pressure drop in the test section. The visualization of flow patterns was possible with the use of a high-speed CMOS camera. The results obtained are in line with those found in the literature, both for flow patterns and for the heat transfer coefficient.Keywords: carbon dioxide, convective boiling, CO₂, mini-channels
Procedia PDF Downloads 164