Search results for: ordinary and extraordinary modes
1116 Magnetohydrodynamics (MHD) Boundary Layer Flow Past A Stretching Plate with Heat Transfer and Viscous Dissipation
Authors: Jiya Mohammed, Tsadu Shuaib, Yusuf Abdulhakeem
Abstract:
The research work focuses on the cases of MHD boundary layer flow past a stretching plate with heat transfer and viscous dissipation. The non-linear of momentum and energy equation are transform into ordinary differential equation by using similarity transformation, the resulting equation are solved using Adomian Decomposition Method (ADM). An attempt has been made to show the potentials and wide range application of the Adomian decomposition method in the comparison with the previous one in solving heat transfer problems. The Pade approximates value (η= 11[11, 11]) is use on the difficulty at infinity. The results are compared by numerical technique method. A vivid conclusion can be drawn from the results that ADM provides highly precise numerical solution for non-linear differential equations. The result where accurate especially for η ≤ 4, a general equating terms of Eckert number (Ec), Prandtl number (Pr) and magnetic parameter ( ) is derived which was used to investigate velocity and temperature profiles in boundary layer.Keywords: MHD, Adomian decomposition, boundary layer, viscous dissipation
Procedia PDF Downloads 5451115 Development of Ornamental Seedlings and Cuttings for Hydroponics Using Different Substrates
Authors: Moustafa A. Fadel, Omar Al Shehhi, Mohsin Al Mussabi, Abdullah Al Ameri
Abstract:
Hydroponics represents an extraordinary promising technique if used efficiently in arid regions where water resources are extremely scarce where a great portion of the used water should be recycled and saved. Available research publications studying the production of seedlings for such purpose are limited. This research paper focuses on investigating the effect of using various substrate materials on the development of seedlings for ornamental plants. Bermuda grass, Petunia (Compacta Enana Rosa) and Epipremnum aureum are used widely in landscape design. Bermuda is used as a turf grass; Petunia is used as a flowering plant and Epipremnum aureum as an indoor ornamental plant in hydroponics. Three substrate materials were used to germinate and propagate the first two and the cuttings of the third one. Synthetic sponge (Polyurethane sponge), Rockwool and sterilized cotton were used as the substrate material in each case where an experimental water-circulating apparatus was designed and installed to execute the test. An experimental setup of closed hydroponic apparatus was developed to carry out the experiment equipped with water recycling circuit and an aeration mechanism pumping air in reservoir in order to increase oxygen levels in the recycled water. Water pumping was programmed in different regimes to allow better aeration for seeds and cuttings under investigation. Results showed that Bermuda grass germinated in Rockwool reached a germination rate of 70% while it did not exceed 50% when sponge and medically treated cotton were used after 15 days. On the other hand the highest germination rate of Petunia was observed when treated cotton was used where it recorded about 30% while it was 22%, and 7% after 20 days where Rockwool and sponge were utilized respectively. Cuttings propagation of Epipremnum aureum developed the highest number of shoots when treated cotton was used where it gave 10 shoots after 10 days while it gave just 7 shoots when Rockwool and sponge were used as the propagation substrate.Keywords: hydroponics, germination, seedlings, cuttings
Procedia PDF Downloads 2851114 Design and Performance Analysis of a Hydro-Power Rim-Driven Superconducting Synchronous Generator
Authors: A. Hassannia, S. Ramezani
Abstract:
The technology of superconductivity has developed in many power system devices such as transmission cable, transformer, current limiter, motor and generator. Superconducting wires can carry high density current without loss, which is the capability that is used to design the compact, lightweight and more efficient electrical machines. Superconducting motors have found applications in marine and air propulsion systems as well as superconducting generators are considered in low power hydraulic and wind generators. This paper presents a rim-driven superconducting synchronous generator for hydraulic power plant. The rim-driven concept improves the performance of hydro turbine. Furthermore, high magnetic field that is produced by superconducting windings allows replacing the rotor core. As a consequent, the volume and weight of the machine is decreased significantly. In this paper, a 1 MW coreless rim-driven superconducting synchronous generator is designed. Main performance characteristics of the proposed machine are then evaluated using finite elements method and compared to an ordinary similar size synchronous generator.Keywords: coreless machine, electrical machine design, hydraulic generator, rim-driven machine, superconducting generator
Procedia PDF Downloads 1691113 Biopics in Hindi Film Industry and the Youth Perception
Authors: Divyani Redhu, Sachin Bharti
Abstract:
India, as a nation, has always been known for its concept of ‘Unity in Diversity’, and the same ideology can very well be witnessed in the kind of cinema that is produced in India. From mythological films in the beginning to historical films and from comedy to the all-entertaining commercial ‘masala’ films, the Indian film industry has time and again catered its viewers with varied flavors on screen. Needless to say that for a film industry which stood at a total value of 183.2 billion in the year 2019 as per the Statista Portal 2020, there is no dearth of viewers and at the same time, to cater to the needs of a humongous viewer base, variety in content needs to be offered. Particularly looking at the filmography of the Hindi film industry of the last decade, undoubtedly, the genre that has risen like a shining star is that of Biopics. Hindi cinema’s never-ending fascination with the biopic has grown stronger and become more evident in recent times. The success of biographical films like Jodha Akbar, The Dirty Picture, Mary Kom, Bajirao Mastani, Neerja, Aligarh, Azhar, etc. seems to have truly reinforced the industry’s faith and put Bollywood on a biopic spree. From films on the lives of sportspersons to those of the actors, gangsters, social workers, historical figures, and extraordinary citizens, the industry has left no stone unturned till now. Also, many more biopics are in the pipeline slated to be released soon. Also, when the film viewers are concerned, India is known as the youngest nation in the world where youth constituted about 34% of the country’s population in 2019, making India the country with maximum young people. Thus, the attempt of the researchers is to understand the perception of youth (15-24 years of age as per the UN) towards the biopic films. The above-mentioned study would be quantitative in nature. For the same, a survey would be conducted in the capital city of India, i.e., Delhi. The tool of the survey would be a questionnaire, and the number of respondents would be 200. The results derived from the study would focus on the film viewing preferences of youth in Delhi, the popularity of biopic films among the youth, reasons for watching biopic films and their overall perception about the same, etc.Keywords: biopics, Delhi, Hindi cinema, India, youth
Procedia PDF Downloads 1111112 An Approach from Fichte as a Response to the Kantian Dualism of Subject and Object: The Unity of the Subject and Object in Both Theoretical and Ethical Possibility
Authors: Mengjie Liu
Abstract:
This essay aims at responding to the Kant arguments on how to fit the self-caused subject into the deterministic object which follows the natural laws. This essay mainly adopts the approach abstracted from Fichte’s “Wissenshaftslehre” (Doctrine of Science) to picture a possible solution to the conciliation of Kantian dualism. The Fichte approach is based on the unity of the theoretical and practical reason, which can be understood as a philosophical abstraction from ordinary experience combining both subject and object. This essay will discuss the general Kantian dualism problem and Fichte’s unity approach in the first part. Then the essay will elaborate on the achievement of this unity of the subject and object through Fichte’s “the I posits itself” process in the second section. The following third section is related to the ethical unity of subject and object based on the Fichte approach. The essay will also discuss the limitation of Fichte’s approach from two perspectives: (1) the theoretical possibility of the existence of the pure I and (2) Schelling’s statement that the Absolute I is a result rather than the originating act. This essay demonstrates a possible approach to unifying the subject and object supported by Fichte’s “Absolute I” and ethical theories and also points out the limitations of Fichte’s theories.Keywords: Fichte, identity, Kantian dualism, Wissenshaftslehre
Procedia PDF Downloads 851111 Effect of Crashed Stone on Properties of Fly Ash Based-Geopolymer Concrete with Local Alkaline Activator in Egypt
Authors: O. M. Omar, G. D. Abd Elhameed, A. M. Heniegal, H. A. Mohamadien
Abstract:
Green concrete are generally composed of recycling materials as hundred or partial percent substitutes for aggregate, cement, and admixture in concrete. To reduce greenhouse gas emissions, efforts are needed to develop environmentally friendly construction materials. Using of fly ash based geopolymer as an alternative binder can help reduce CO2 emission of concrete. The binder of geopolymer concrete is different from the ordinary Portland cement concrete. Geopolymer Concrete specimens were prepared with different concentration of NaOH solution M10, M14, and, M16 and cured at 60 ºC in duration of 24 hours and 8 hours, in addition to the curing in direct sunlight. Thus, it is necessary to study the effects of the geopolymer binder on the behavior of concrete. Concrete is made by using geopolymer technology is environmental friendly and could be considered as part of the sustainable development. In this study the Local Alkaline Activator in Egypt and dolomite as coarse aggregate in fly ash based-geopolymer concrete was investigated. This paper illustrates the development of mechanical properties. Since the gained compressive strength for geopolymer concrete at 28 days was in the range of 22.5MPa – 43.9MPa.Keywords: geopolymer, molarity, sodium hydroxide, sodium silicate
Procedia PDF Downloads 2861110 IT Systems of the US Federal Courts, Justice, and Governance
Authors: Joseph Zernik
Abstract:
The mechanics of rip currents are complex, involving interactions between waves, currents, water levels and the bathymetry, that present particular challenges for numerical models. Here, the effects of a grid-spacing dependent horizontal mixing on the wave-current interactions are studied. Near the shore, wave rays diverge from channels towards bar crests because of refraction by topography and currents, in a way that depends on the rip current intensity which is itself modulated by the horizontal mixing. At low resolution with the grid-spacing dependent horizontal mixing, the wave motion is the same for both coupling modes because the wave deviation by the currents is weak. In high-resolution case, however, classical results are found with the stabilizing effect of the flow by feedback of waves on currents. Lastly, wave-current interactions and the horizontal mixing strongly affect the intensity of the three-dimensional rip velocity.Keywords: e-justice, federal courts, human rights, banking regulation, United States
Procedia PDF Downloads 3691109 Unveiling the Black Swan of the Inflation-Adjusted Real Excess Returns-Risk Nexus: Evidence From Pakistan Stock Exchange
Authors: Mohammad Azam
Abstract:
The purpose of this study is to investigate risk and real excess portfolio returns using inflation adjusted risk-free rates, a measuring technique that focuses on the momentum augmented Fama-French six-factor model and use monthly data from 1994 to 2022. With the exception of profitability, the data show that market, size, value, momentum, and investment factors are all strongly associated to excess portfolio stock returns using ordinary lease square regression technique. According to the Gibbons, Ross, and Shanken test, the momentum augmented Fama-French six-factor model outperforms the market. This technique discovery may be utilised by academics and professionals to acquire an in-depth knowledge of the Pakistan Stock Exchange across a broad stock pattern for investing decisions and portfolio construction.Keywords: real excess portfolio returns, momentum augmented fama & french five-factor model, GRS-test, pakistan stock exchange
Procedia PDF Downloads 971108 Turbulence Modeling and Wave-Current Interactions
Authors: A. C. Bennis, F. Dumas, F. Ardhuin, B. Blanke
Abstract:
The mechanics of rip currents are complex, involving interactions between waves, currents, water levels and the bathymetry, that present particular challenges for numerical models. Here, the effects of a grid-spacing dependent horizontal mixing on the wave-current interactions are studied. Near the shore, wave rays diverge from channels towards bar crests because of refraction by topography and currents, in a way that depends on the rip current intensity which is itself modulated by the horizontal mixing. At low resolution with the grid-spacing dependent horizontal mixing, the wave motion is the same for both coupling modes because the wave deviation by the currents is weak. In high-resolution case, however, classical results are found with the stabilizing effect of the flow by feedback of waves on currents. Lastly, wave-current interactions and the horizontal mixing strongly affect the intensity of the three-dimensional rip velocity.Keywords: numerical modeling, wave-current interactions, turbulence modeling, rip currents
Procedia PDF Downloads 4621107 Mechanical Model of Gypsum Board Anchors Subjected Cyclic Shear Loading
Authors: Yoshinori Kitsutaka, Fumiya Ikedo
Abstract:
In this study, the mechanical model of various anchors embedded in gypsum board subjected cyclic shear loading were investigated. Shear tests for anchors embedded in 200 mm square size gypsum board were conducted to measure the load - load displacement curves. The strength of the gypsum board was changed for three conditions and 12 kinds of anchors were selected which were ordinary used for gypsum board anchoring. The loading conditions were a monotonous loading and a cyclic loading controlled by a servo-controlled hydraulic loading system to achieve accurate measurement. The fracture energy for each of the anchors was estimated by the analysis of consumed energy calculated by the load - load displacement curve. The effect of the strength of gypsum board and the types of anchors on the shear properties of gypsum board anchors was cleared. A numerical model to predict the load-unload curve of shear deformation of gypsum board anchors caused by such as the earthquake load was proposed and the validity on the model was proved.Keywords: gypsum board, anchor, shear test, cyclic loading, load-unload curve
Procedia PDF Downloads 3791106 Three Dimensional Analysis of Cubesat Thermal Vacuum Test
Authors: Maged Assem Soliman Mossallam
Abstract:
Thermal vacuum testing target is to qualify the space system and ensure its operability under harsh space environment. The functionality of the cubesat was checked at extreme orbit conditions. Test was performed for operational and nonoperational modes. Analysis is done to simulate the cubesat thermal cycling inside thermal vacuum chamber. Comsol Multiphysics finite element is used to solve three dimensional problem for the cubesat inside TVAC. Three dimensional CAD model is done using Autodesk Inventor program. The boundary conditions were applied from the actual shroud temperature. The input heat load variation with time is considered to solve the transient three dimensional problem. Results show that the simulated temperature profiles are within an acceptable range from the real testing data.Keywords: cubesat, thermal vacuum test, testing simulation, finite element analysis
Procedia PDF Downloads 1391105 Designing Emergency Response Network for Rail Hazmat Shipments
Authors: Ali Vaezi, Jyotirmoy Dalal, Manish Verma
Abstract:
The railroad is one of the primary transportation modes for hazardous materials (hazmat) shipments in North America. Installing an emergency response network capable of providing a commensurate response is one of the primary levers to contain (or mitigate) the adverse consequences from rail hazmat incidents. To this end, we propose a two-stage stochastic program to determine the location of and equipment packages to be stockpiled at each response facility. The raw input data collected from publicly available reports were processed, fed into the proposed optimization program, and then tested on a realistic railroad network in Ontario (Canada). From the resulting analyses, we conclude that the decisions based only on empirical datasets would undermine the effectiveness of the resulting network; coverage can be improved by redistributing equipment in the network, purchasing equipment with higher containment capacity, and making use of a disutility multiplier factor.Keywords: hazmat, rail network, stochastic programming, emergency response
Procedia PDF Downloads 1751104 Climate Change and Variability-Induced Resource Based Conflicts: The Case of the Issa, Ittu and Afar (Agro) Pastoralists of Eastern Ethiopia
Authors: Bamlaku Tadesse Mengistu
Abstract:
This article explores the link between climate change/variability and its adaptation/coping strategies with resource-based ethnic conflicts among the Afar, Issa-Somali, and Ittu-Oromo ethnic groups. The qualitative data were collected from community leaders, ordinary members of the communities, and administrative and political bodies at various levels through one-on-one interviews, focus group discussions and field observations. The quantitative data were also collected through a household survey from the randomly selected 128 households drawn from the three districts of Mieso-Mullu, Mieso, and Amibara districts. The study shows that there is a causal relationship between resource scarcity impacted by climate change/variability and ethnic conflicts. The study reveals that the increasing nature of resource scarcity and environmental problems, and also the changing nature of ethnic diversity will aggravate the resource-based inter-ethnic conflicts.Keywords: Eastern Ethiopia, ethnic conflict, climate change, Afar, Issa, Ittu
Procedia PDF Downloads 1861103 Vibration Analysis of Power Lines with Moving Dampers
Authors: Mohammad Bukhari, Oumar Barry
Abstract:
In order to reduce the Aeolian vibration of overhead transmission lines, the Stockbridge damper is usually attached. The efficiency of Stockbridge damper depends on its location on the conductor and its resonant frequencies. When the Stockbridge damper is located on a vibration node, it becomes inefficient. Hence, the static damper should be subrogated by a dynamic one. In the present study, a proposed dynamic absorber for transmission lines is studied. Hamilton’s principle is used to derive the governing equations, then the system of ordinary differential equations is solved numerically. Parametric studies are conducted to determine how certain parameters affect the performance of the absorber. The results demonstrate that replacing the static absorber by a dynamic one enhance the absorber performance for wider range of frequencies. The results also indicate that the maximum displacement decreases as the absorber speed and the forcing frequency increase. However, this reduction in maximum displacement is accompanying with increasing in the steady state vibration displacement. It is also indicated that the energy dissipation in moving absorber covers higher range of frequencies.Keywords: absorber performance, Aeolian vibration, Hamilton’s principle, stockbridge damper
Procedia PDF Downloads 2591102 Haunted Pilgrims: The Absence of Touch and the Sounds of Silence in Online Communication
Authors: Karen Armstrong
Abstract:
This paper explores the impact of two aspects of online communication: the absence of touch and the sound of silence. In order to place the discussion in context, the paper begins with a brief description of communication itself and the many ways in which we communicate with each other both verbally and non-verbally. Next, the discussion moves to consider the general characteristics of online communication and the ways in which it is similar as well as very different from face to face communication. This examination considers the ways we communicate primarily in email, but also through texting, instagram stickers, and twitter—the primary modes of online communication aside from face to face videos, which are less common. With few exceptions of course, most such interactions take place without sound or physical contact. First to be examined is the absence of touch, followed by the presence of silence. The paper explores these issues, concluding with the ways in which both absence of touch and the prevalence of silence are important determinants shaping communication in our online universe.Keywords: absence of touch, communication, face-to-face, haptics, online, silence
Procedia PDF Downloads 3641101 Lambda-Levelwise Statistical Convergence of a Sequence of Fuzzy Numbers
Authors: F. Berna Benli, Özgür Keskin
Abstract:
Lately, many mathematicians have been studied the statistical convergence of a sequence of fuzzy numbers. We know that Lambda-statistically convergence is a kind of convergence between ordinary convergence and statistical convergence. In this paper, we will introduce the new kind of convergence such as λ-levelwise statistical convergence. Then, we will define the concept of the λ-levelwise statistical cluster and limit points of a sequence of fuzzy numbers. Also, we will discuss the relations between the sets of λ-levelwise statistical cluster points and λ-levelwise statistical limit points of sequences of fuzzy numbers. This work has been extended in this paper, where some relations have been considered such that when lambda-statistical limit inferior and lambda-statistical limit superior for lambda-statistically convergent sequences of fuzzy numbers are equal. Furthermore, lambda-statistical boundedness condition for different sequences of fuzzy numbers has been studied.Keywords: fuzzy number, λ-levelwise statistical cluster points, λ-levelwise statistical convergence, λ-levelwise statistical limit points, λ-statistical cluster points, λ-statistical convergence, λ-statistical limit points
Procedia PDF Downloads 4701100 Computational Analysis on Thermal Performance of Chip Package in Electro-Optical Device
Authors: Long Kim Vu
Abstract:
The central processing unit in Electro-Optical devices is a Field-programmable gate array (FPGA) chip package allowing flexible, reconfigurable computing but energy consumption. Because chip package is placed in isolated devices based on IP67 waterproof standard, there is no air circulation and the heat dissipation is a challenge. In this paper, the author successfully modeled a chip package which various interposer materials such as silicon, glass and organics. Computational fluid dynamics (CFD) was utilized to analyze the thermal performance of chip package in the case of considering comprehensive heat transfer modes: conduction, convection and radiation, which proposes equivalent heat dissipation. The logic chip temperature varying with time is compared between the simulation and experiment results showing the excellent correlation, proving the reasonable chip modeling and simulation method.Keywords: CFD, FPGA, heat transfer, thermal analysis
Procedia PDF Downloads 1771099 The Modality of Multivariate Skew Normal Mixture
Authors: Bader Alruwaili, Surajit Ray
Abstract:
Finite mixtures are a flexible and powerful tool that can be used for univariate and multivariate distributions, and a wide range of research analysis has been conducted based on the multivariate normal mixture and multivariate of a t-mixture. Determining the number of modes is an important activity that, in turn, allows one to determine the number of homogeneous groups in a population. Our work currently being carried out relates to the study of the modality of the skew normal distribution in the univariate and multivariate cases. For the skew normal distribution, the aims are associated with studying the modality of the skew normal distribution and providing the ridgeline, the ridgeline elevation function, the $\Pi$ function, and the curvature function, and this will be conducive to an exploration of the number and location of mode when mixing the two components of skew normal distribution. The subsequent objective is to apply these results to the application of real world data sets, such as flow cytometry data.Keywords: mode, modality, multivariate skew normal, finite mixture, number of mode
Procedia PDF Downloads 4841098 Soft Exoskeleton Elastomer Pre-Tension Drive Control System
Authors: Andrey Yatsun, Andrei Malchikov
Abstract:
Exoskeletons are used to support and compensate for the load on the human musculoskeletal system. Elastomers are an important component of exoskeletons, providing additional support and compensating for the load. The algorithm of the active elastomer tension system provides the required auxiliary force depending on the angle of rotation and the tilt speed of the operator's torso. Feedback for the drive is provided by a force sensor integrated into the attachment of the exoskeleton vest. The use of direct force measurement ensures the required accuracy in all settings of the man-machine system. Non-adjustable elastic elements make it difficult to move without load, tilt forward and walk. A strategy for the organization of the auxiliary forces management system is proposed based on the allocation of 4 operating modes of the human-machine system.Keywords: soft exoskeleton, mathematical modeling, pre-tension elastomer, human-machine interaction
Procedia PDF Downloads 601097 Semiconductor Nanofilm Based Schottky-Barrier Solar Cells
Authors: Mariyappan Shanmugam, Bin Yu
Abstract:
Schottky-barrier solar cells are demonstrated employing 2D-layered MoS2 and WS2 semiconductor nanofilms as photo-active material candidates synthesized by chemical vapor deposition method. Large area MoS2 and WS2 nanofilms are stacked by layer transfer process to achieve thicker photo-active material studied by atomic force microscopy showing a thickness in the range of ~200 nm. Two major vibrational active modes associated with 2D-layered MoS2 and WS2 are studied by Raman spectroscopic technique to estimate the quality of the nanofilms. Schottky-barrier solar cells employed MoS2 and WS2 active materials exhibited photoconversion efficiency of 1.8 % and 1.7 % respectively. Fermi-level pinning at metal/semiconductor interface, electronic transport and possible recombination mechanisms are studied in the Schottky-barrier solar cells.Keywords: two-dimensional nanosheet, graphene, hexagonal boron nitride, solar cell, Schottky barrier
Procedia PDF Downloads 3251096 Magnetohydrodynamic (MHD) Flow of Cu-Water Nanofluid Due to a Rotating Disk with Partial Slip
Authors: Tasawar Hayat, Madiha Rashid, Maria Imtiaz, Ahmed Alsaedi
Abstract:
This problem is about the study of flow of viscous fluid due to rotating disk in nanofluid. Effects of magnetic field, slip boundary conditions and thermal radiations are encountered. An incompressible fluid soaked the porous medium. In this model, nanoparticles of Cu is considered with water as the base fluid. For Copper-water nanofluid, graphical results are presented to describe the influences of nanoparticles volume fraction (φ) on velocity and temperature fields for the slip boundary conditions. The governing differential equations are transformed to a system of nonlinear ordinary differential equations by suitable transformations. Convergent solution of the nonlinear system is developed. The obtained results are analyzed through graphical illustrations for different parameters. Moreover, the features of the flow and heat transfer characteristics are analyzed. It is found that the skin friction coefficient and heat transfer rate at the surface are highest in copper-water nanofluid.Keywords: MHD nanofluid, porous medium, rotating disk, slip effect
Procedia PDF Downloads 2521095 Crystalline Silicon Optical Whispering Gallery Mode (WGM) Resonators for Precision Measurements
Authors: Igor Bilenko, Artem Shitikov, Michael Gorodetsky
Abstract:
Optical whispering gallery mode (WGM) resonators combine very high optical quality factor (Q) with small size. Resonators made from low loss crystalline fluorites (CaF2, MgF2) may have Q as high as 1010 that make them unique devices for modern applications including ultrasensitive sensors, frequency control, and precision spectroscopy. While silicon is a promising material transparent from near infrared to terahertz frequencies, fundamental limit for Si WGM quality factor was not reached yet. In our paper, we presented experimental results on the preparation and testing of resonators at 1550 nm wavelength made from crystalline silicon grown and treated by different techniques. Q as high as 3x107 was demonstrated. Future steps need to reach a higher value and possible applications are discussed.Keywords: optical quality factor, silicon optical losses, silicon optical resonator, whispering gallery modes
Procedia PDF Downloads 4881094 Damage in Cementitious Materials Exposed to Sodium Chloride Solution and Thermal Cycling: The Effect of Using Supplementary Cementitious Materials
Authors: Fadi Althoey, Yaghoob Farnam
Abstract:
Sodium chloride (NaCl) can interact with the tricalcium aluminate (C3A) and its hydrates in concrete matrix. This interaction can result in formation of a harmful chemical phase as the temperature changes. It is thought that this chemical phase is embroiled in the premature concrete deterioration in the cold regions. This work examines the potential formation of the harmful chemical phase in various pastes prepared by using different types of ordinary portland cement (OPC) and supplementary cementitious materials (SCMs). The quantification of the chemical phase was done by using a low temperature differential scanning calorimetry. The results showed that the chemical phase formation can be reduced by using Type V cement (low content of C3A). The use of SCMs showed different behaviors on the formation of the chemical phase. Slag and Class F fly ash can reduce the chemical phase by the dilution of cement whereas silica fume can reduce the amount of the chemical phase by dilution and pozzolanic activates. Interestingly, the use of Class C fly ash has a negative effect on concrete exposed to NaCl through increasing the formation of the chemical phase.Keywords: concrete, damage, chemcial phase, NaCl, SCMs
Procedia PDF Downloads 1351093 Diagonal Crack Width of RC Members with High Strength Materials
Authors: J. Y. Lee, H. S. Lim, S. H. Yoon
Abstract:
This paper presents an analysis of the diagonal crack widths of RC members with various types of materials by simulating a compatibility-aided truss model. The analytical results indicated that the diagonal crack width was influenced by not only the shear reinforcement ratio but also the yield strength of shear reinforcement and the compressive strength of concrete. The yield strength of shear reinforcement and the compressive strength of concrete decreased the diagonal shear crack width of RC members for the same shear force because of the change of shear failure modes. However, regarding the maximum shear crack width at shear failure, the shear crack width of the beam with high strength materials was greater than that of the beam with normal strength materials.Keywords: diagonal crack width, high strength stirrups, high strength concrete, RC members, shear behavior
Procedia PDF Downloads 3021092 Evaluation of Applicability of High Strength Stirrup for Prestressed Concrete Members
Authors: J.-Y. Lee, H.-S. Lim, S.-E. Kim
Abstract:
Recently, the use of high-strength materials is increasing as the construction of large structures and high-rise structures increases. This paper presents an analysis of the shear behavior of prestressed concrete members with various types of materials by simulating a finite element (FE) analysis. The analytical results indicated that the shear strength and shear failure mode were strongly influenced by not only the shear reinforcement ratio but also the yield strength of shear reinforcement and the compressive strength of concrete. Though the yield strength of shear reinforcement increased the shear strength of prestressed concrete members, there was a limit to the increase in strength because of the change of shear failure modes. According to the results of FE analysis on various parameters, the maximum yield strength of the steel stirrup that can be applied to prestressed concrete members was about 860 MPa.Keywords: prestressed concrete members, high strength reinforcing bars, high strength concrete, shear behavior
Procedia PDF Downloads 2941091 The Influence of Remuneration Committees, Directors' Shareholding and Institutional Ownership on the Remuneration of Directors in the Large Listed Companies in South Africa
Authors: Henriette Scholtz
Abstract:
Excessive executive directors’ remuneration remains a major concern for many stakeholders and are some of the factors to blame for the recent global financial crisis. The objective of this study was to examine whether certain firm characteristics are an effective way of protecting shareholders’ interests with respect to executive directors’ remuneration. To achieve this, an ordinary least squares model was used to test the relationship between the remuneration of executive directors and a number of firm and corporate governance characteristics to determine whether these characteristics have an influence on executive directors’ remuneration of large listed companies in South Africa. It was found that corporate governance reforms relating to institutional ownership, shareholder voting on the remuneration policy and the number of remuneration committee meetings acts as an effective governance tool to protect shareholder’s interests with regard to executive remuneration. There is no evidence that the number of non-executive directors on the remuneration committee has an influence on the executive directors’ remuneration.Keywords: executive directors’ remuneration, agency theory, corporate governance, remuneration committee, directors’ shareholding, institutional ownership
Procedia PDF Downloads 1991090 Objectives of the Standardization of Technical Terminology Nowadays in Albanian
Authors: Gani Pllana
Abstract:
In the conditions of the rapid development of technics and technology in recent years, the cooperation of the scientific-technical language with the standard Albanian language is continuing with a higher intensity than before. We notice a vigor of enrichment in the vocabulary of technical terminology, due to the birth and formation of new fields and subfields of technics, technology, as computing, mechatronics, telemetry, a multitude of concepts many of which, on the one hand, are marked with names of the languages they come from, mainly from English, but on the other hand, they meet their needs with the lexical mother tongue composition (by common words being raised to terms) and with the activation of other layers, such as compound word terms. Thus, for example, in the field of computing, we notice in it the inclusion of the ordinary vocabulary for reproductive reasons, like mi, dritare, flamur, adresë, skedar (Engl: mouse, window, flag, address, file), and along with them, the compound word terms, serving to differentiate relevant concepts, like, adresë e hiperlidhjes, adresë e uebit, adresë relative, adresë virtuale (Engl. address hyperlink, web address, relative address, virtual address) etc.Keywords: common words, Albanian language, technical terminology, standardization
Procedia PDF Downloads 2841089 Terahertz Surface Plasmon in Carbon Nanotube Dielectric Interface via Amplitude Modulated Laser
Authors: Monika Singh
Abstract:
A carbon nanotube thin film coated on dielectric interface is employed to produce THz surface plasma wave (SPW). The carbon nanotube has its plasmon frequency in the THz range. The SPW field falls off away from the metal film both inside the dielectric as well as in free space. An amplitude modulated laser pulse normally incident, from free space on slow wave structure, exert a modulation frequency ponderomotive force on the free electrons of the CNT film and resonantly excite the THz surface plasma wave at the modulation frequency. Carbon nanotube based plasmonic nano-structure materials provides potentially more versatile approach to tightly confined surface modes in the THz range in comparison to noble metals.Keywords: surface plasmons, surface waves, thin films, THz radiation
Procedia PDF Downloads 3871088 The Impact of Corporate Social Responsibility Information Disclosure on the Accuracy of Analysts' Earnings Forecasts
Authors: Xin-Hua Zhao
Abstract:
In recent years, the growth rate of social responsibility reports disclosed by Chinese corporations has grown rapidly. The economic effects of the growing corporate social responsibility reports have become a hot topic. The article takes the chemical listed engineering corporations that disclose social responsibility reports in China as a sample, and based on the information asymmetry theory, examines the economic effect generated by corporate social responsibility disclosure with the method of ordinary least squares. The research is conducted from the perspective of analysts’ earnings forecasts and studies the impact of corporate social responsibility information disclosure on improving the accuracy of analysts' earnings forecasts. The results show that there is a statistically significant negative correlation between corporate social responsibility disclosure index and analysts’ earnings forecast error. The conclusions confirm that enterprises can reduce the asymmetry of social and environmental information by disclosing social responsibility reports, and thus improve the accuracy of analysts’ earnings forecasts. It can promote the effective allocation of resources in the market.Keywords: analysts' earnings forecasts, corporate social responsibility disclosure, economic effect, information asymmetry
Procedia PDF Downloads 1501087 Multi-Period Supply Chain Design under Uncertainty
Authors: Amir Azaron
Abstract:
In this research, a stochastic programming approach is developed for designing supply chains with uncertain parameters. Demands and selling prices of products at markets are considered as the uncertain parameters. The proposed mathematical model will be multi-period two-stage stochastic programming, which takes into account the selection of retailer sites, suppliers, production levels, inventory levels, transportation modes to be used for shipping goods, and shipping quantities among the entities of the supply chain network. The objective function is to maximize the chain’s net present value. In order to maximize the chain’s NPV, the sum of first-stage investment costs on retailers, and the expected second-stage processing, inventory-holding and transportation costs should be kept as low as possible over multiple periods. The effects of supply uncertainty where suppliers are unreliable will also be investigated on the efficiency of the supply chain.Keywords: supply chain management, stochastic programming, multiobjective programming, inventory control
Procedia PDF Downloads 291