Search results for: structural equation model (SEM)
3953 Design and Synthesis of Two Tunable Bandpass Filters Based on Varactors and Defected Ground Structure
Authors: M'Hamed Boulakroune, Mouloud Challal, Hassiba Louazene, Saida Fentiz
Abstract:
This paper presents a new ultra wideband (UWB) microstrip bandpass filter (BPF) at microwave frequencies. The first one is based on multiple-mode resonator (MMR) and rectangular-shaped defected ground structure (DGS). This filter, which is compact size of 25.2 x 3.8 mm2, provides in the pass band an insertion loss of 0.57 dB and a return loss greater than 12 dB. The second structure is a tunable bandpass filters using planar patch resonators based on diode varactor. This filter is formed by a triple mode circular patch resonator with two pairs of slots, in which the varactors are connected. Indeed, this filter is initially centered at 2.4 GHz, the center frequency of the tunable patch filter could be tuned up to 1.8 GHz simultaneously with the bandwidth, reaching high tuning ranges. Lossless simulations were compared to those considering the substrate dielectric, conductor losses, and the equivalent electrical circuit model of the tuning element in order to assess their effects. Within these variations, simulation results showed insertion loss better than 2 dB and return loss better than 10 dB over the passband. The proposed filters presents good performances and the simulation results are in satisfactory agreement with the experimentation ones reported elsewhere.Keywords: defected ground structure, diode varactor, microstrip bandpass filter, multiple-mode resonator
Procedia PDF Downloads 3123952 A Neural Network Control for Voltage Balancing in Three-Phase Electric Power System
Authors: Dana M. Ragab, Jasim A. Ghaeb
Abstract:
The three-phase power system suffers from different challenging problems, e.g. voltage unbalance conditions at the load side. The voltage unbalance usually degrades the power quality of the electric power system. Several techniques can be considered for load balancing including load reconfiguration, static synchronous compensator and static reactive power compensator. In this work an efficient neural network is designed to control the unbalanced condition in the Aqaba-Qatrana-South Amman (AQSA) electric power system. It is designed for highly enhanced response time of the reactive compensator for voltage balancing. The neural network is developed to determine the appropriate set of firing angles required for the thyristor-controlled reactor to balance the three load voltages accurately and quickly. The parameters of AQSA power system are considered in the laboratory model, and several test cases have been conducted to test and validate the proposed technique capabilities. The results have shown a high performance of the proposed Neural Network Control (NNC) technique for correcting the voltage unbalance conditions at three-phase load based on accuracy and response time.Keywords: three-phase power system, reactive power control, voltage unbalance factor, neural network, power quality
Procedia PDF Downloads 1953951 Methodology of Preliminary Design and Performance of a Axial-Flow Fan through CFD
Authors: Ramiro Gustavo Ramirez Camacho, Waldir De Oliveira, Eraldo Cruz Dos Santos, Edna Raimunda Da Silva, Tania Marie Arispe Angulo, Carlos Eduardo Alves Da Costa, Tânia Cristina Alves Dos Reis
Abstract:
It presents a preliminary design methodology of an axial fan based on the lift wing theory and the potential vortex hypothesis. The literature considers a study of acoustic and engineering expertise to model a fan with low noise. Axial fans with inadequate intake geometry, often suffer poor condition of the flow at the entrance, varying from velocity profiles spatially asymmetric to swirl floating with respect to time, this produces random forces acting on the blades. This produces broadband gust noise which in most cases triggers the tonal noise. The analysis of the axial flow fan will be conducted for the solution of the Navier-Stokes equations and models of turbulence in steady and transitory (RANS - URANS) 3-D, in order to find an efficient aerodynamic design, with low noise and suitable for industrial installation. Therefore, the process will require the use of computational optimization methods, aerodynamic design methodologies, and numerical methods as CFD- Computational Fluid Dynamics. The objective is the development of the methodology of the construction axial fan, provide of design the geometry of the blade, and evaluate aerodynamic performanceKeywords: Axial fan design, CFD, Preliminary Design, Optimization
Procedia PDF Downloads 3963950 Evaluating Machine Learning Techniques for Activity Classification in Smart Home Environments
Authors: Talal Alshammari, Nasser Alshammari, Mohamed Sedky, Chris Howard
Abstract:
With the widespread adoption of the Internet-connected devices, and with the prevalence of the Internet of Things (IoT) applications, there is an increased interest in machine learning techniques that can provide useful and interesting services in the smart home domain. The areas that machine learning techniques can help advance are varied and ever-evolving. Classifying smart home inhabitants’ Activities of Daily Living (ADLs), is one prominent example. The ability of machine learning technique to find meaningful spatio-temporal relations of high-dimensional data is an important requirement as well. This paper presents a comparative evaluation of state-of-the-art machine learning techniques to classify ADLs in the smart home domain. Forty-two synthetic datasets and two real-world datasets with multiple inhabitants are used to evaluate and compare the performance of the identified machine learning techniques. Our results show significant performance differences between the evaluated techniques. Such as AdaBoost, Cortical Learning Algorithm (CLA), Decision Trees, Hidden Markov Model (HMM), Multi-layer Perceptron (MLP), Structured Perceptron and Support Vector Machines (SVM). Overall, neural network based techniques have shown superiority over the other tested techniques.Keywords: activities of daily living, classification, internet of things, machine learning, prediction, smart home
Procedia PDF Downloads 3573949 Elite Rain: A Solution to the Problem of Destructive Processes in Iran and Other Countries
Authors: Khaled Ali Soltan
Abstract:
Iran can be considered a triangle that is affected by 3 forces: the government, the elite, and the people. Over the last 100 years, these three forces have been at odds with each other. This lack of coordination and sometimes antagonism among these three forces has led to lawlessness in Iran (both the government and the people have entered the cycle of lawlessness) and the spread of destructive processes in the country and the destruction of resources, both natural and human resources. The direct and negative impact of this issue on people's lives as well as the environment highlights the importance of this article. This article descriptively deals with the issue and suggests solutions and examines possible problems and obstacles. There seems to be a way to establish a connection’ closeness and coordination among these three forces and put them on the path of development. ELITE RAIN is a scientific-popular process that can create coordination and cooperation between these forces, prevent destructive processes in the country and put it on the path of sustainable development and a better life. This solution is a more advanced model of brainstorming technique introduced by Alex Osborn in 1953. Given that people have tried different types of protests to improve the status quo, such as the change of government in 1979 which led to the establishment of the theocracy, participating in elections that resulted in more frustration and corruption due to the lack of real parties, and sporadic street protests that resulted in nothing more than repression, it seems that this solution can be successful.Keywords: corruption, destruction of resources, elite rain, Iran, legal complaints, sustainable development, the elite
Procedia PDF Downloads 723948 The Role of Teaching Assistants for Deaf Pupils in a Mainstream Primary School in England
Authors: Hatice Yildirim
Abstract:
This study was an investigation into the role of teaching assistants (TAs) for deaf pupils in an English primary school. This study aimed to provide knowledge about how TAs support deaf pupils in mainstream schools in England. It is accepted that TAs have an important role in the inclusion of students with disabilities in mainstream schools. However, there has been a lack of attention paid to the role of TAs for deaf pupils in the literature. A qualitative case study approach was used to address the research questions. Twelve semi-structured classroom observations and six semi-structured interviews were carried out with four TAs and two teachers in one English mainstream primary school. The data analysis followed a thematic analysis framework. The results indicated that TAs are utilised based on a one-on-one support model and are deployed under the class teachers in the classroom. The classroom activities are carried out in small groups with the TAs and the class teacher’s agreement, as per the school’s policy. Findings show that TAs carried out seven different roles in the education of deaf pupils in an English mainstream primary school. Supporting the academic and social development of deaf pupils is TA`s main role. Also, they record pupils’ progress, communicate with pupils’ parents, take on a pastoral care role, tutor pupils in additional support lessons and raise awareness of deaf pupils’ issues.Keywords: deaf, mainstream primary school, teaching assistant, teaching assistant`s roles
Procedia PDF Downloads 2043947 Management and Evaluation of the Importance of Porous Media in Biomedical Engineering as Associated with Magnetic Resonance Imaging Besides Drug Delivery
Authors: Fateme Nokhodchi Bonab
Abstract:
Studies related to magnetic resonance imaging (MRI) and drug delivery are reviewed in this study to demonstrate the role of transport theory in porous media in facilitating advances in biomedical applications. Diffusion processes are believed to be important in many therapeutic modalities such as: B. Delivery of drugs to the brain. We analyse the progress in the development of diffusion equations using the local volume average method and the evaluation of applications related to diffusion equations. Torsion and porosity have significant effects on diffusive transport. In this study, various relevant models of torsion are presented and mathematical modeling of drug release from biodegradable delivery systems is analysed. In this study, a new model of drug release kinetics from porous biodegradable polymeric microspheres under bulk and surface erosion of the polymer matrix is presented. Solute drug diffusion, drug dissolution from the solid phase, and polymer matrix erosion have been found to play a central role in controlling the overall drug release process. This work paves the way for MRI and drug delivery researchers to develop comprehensive models based on porous media theory that use fewer assumptions compared to other approaches.Keywords: MRI, porous media, drug delivery, biomedical applications
Procedia PDF Downloads 903946 Analysis of Influence of Geometrical Set of Nozzles on Aerodynamic Drag Level of a Hero’s Based Steam Turbine
Authors: Mateusz Paszko, Miroslaw Wendeker, Adam Majczak
Abstract:
High temperature waste energy offers a number of management options. The most common energy recuperation systems, that are actually used to utilize energy from the high temperature sources are steam turbines working in a high pressure and temperature closed cycles. Due to the high costs of production of energy recuperation systems, especially rotary turbine discs equipped with blades, currently used solutions are limited in use with waste energy sources of temperature below 100 °C. This study presents the results of simulating the flow of the water vapor in various configurations of flow ducts in a reaction steam turbine based on Hero’s steam turbine. The simulation was performed using a numerical model and the ANSYS Fluent software. Simulation computations were conducted with use of the water vapor as an internal agent powering the turbine, which is fully safe for an environment in case of a device failure. The conclusions resulting from the conducted numerical computations should allow for optimization of the flow ducts geometries, in order to achieve the greatest possible efficiency of the turbine. It is expected that the obtained results should be useful for further works related to the development of the final version of a low drag steam turbine dedicated for low cost energy recuperation systems.Keywords: energy recuperation, CFD analysis, waste energy, steam turbine
Procedia PDF Downloads 2103945 Evaluation of Deformable Boundary Condition Using Finite Element Method and Impact Test for Steel Tubes
Authors: Abed Ahmed, Mehrdad Asadi, Jennifer Martay
Abstract:
Stainless steel pipelines are crucial components to transportation and storage in the oil and gas industry. However, the rise of random attacks and vandalism on these pipes for their valuable transport has led to more security and protection for incoming surface impacts. These surface impacts can lead to large global deformations of the pipe and place the pipe under strain, causing the eventual failure of the pipeline. Therefore, understanding how these surface impact loads affect the pipes is vital to improving the pipes’ security and protection. In this study, experimental test and finite element analysis (FEA) have been carried out on EN3B stainless steel specimens to study the impact behaviour. Low velocity impact tests at 9 m/s with 16 kg dome impactor was used to simulate for high momentum impact for localised failure. FEA models of clamped and deformable boundaries were modelled to study the effect of the boundaries on the pipes impact behaviour on its impact resistance, using experimental and FEA approach. Comparison of experimental and FE simulation shows good correlation to the deformable boundaries in order to validate the robustness of the FE model to be implemented in pipe models with complex anisotropic structure.Keywords: dynamic impact, deformable boundary conditions, finite element modelling, LS-DYNA, stainless steel pipe
Procedia PDF Downloads 1493944 Non-Destructive Evaluation for Physical State Monitoring of an Angle Section Thin-Walled Curved Beam
Authors: Palash Dey, Sudip Talukdar
Abstract:
In this work, a cross-breed approach is presented for obtaining both the amount of the damage intensity and location of damage existing in thin-walled members. This cross-breed approach is developed based on response surface methodology (RSM) and genetic algorithm (GA). Theoretical finite element (FE) model of cracked angle section thin walled curved beam has been linked to the developed approach to carry out trial experiments to generate response surface functions (RSFs) of free, forced and heterogeneous dynamic response data. Subsequently, the error between the computed response surface functions and measured dynamic response data has been minimized using GA to find out the optimum damage parameters (amount of the damage intensity and location). A single crack of varying location and depth has been considered in this study. The presented approach has been found to reveal good accuracy in prediction of crack parameters and possess great potential in crack detection as it requires only the current response of a cracked beam.Keywords: damage parameters, finite element, genetic algorithm, response surface methodology, thin walled curved beam
Procedia PDF Downloads 2483943 Design and Control of a Knee Rehabilitation Device Using an MR-Fluid Brake
Authors: Mina Beheshti, Vida Shams, Mojtaba Esfandiari, Farzaneh Abdollahi, Abdolreza Ohadi
Abstract:
Most of the people who survive a stroke need rehabilitation tools to regain their mobility. The core function of these devices is a brake actuator. The goal of this study is to design and control a magnetorheological brake which can be used as a rehabilitation tool. In fact, the fluid used in this brake is called magnetorheological fluid or MR that properties can change by variation of the magnetic field. The braking properties can be set as control by using this feature of the fluid. In this research, different MR brake designs are first introduced in each design, and the dimensions of the brake have been determined based on the required torque for foot movement. To calculate the brake dimensions, it is assumed that the shear stress distribution in the fluid is uniform and the fluid is in its saturated state. After designing the rehabilitation brake, the mathematical model of the healthy movement of a healthy person is extracted. Due to the nonlinear nature of the system and its variability, various adaptive controllers, neural networks, and robust have been implemented to estimate the parameters and control the system. After calculating torque and control current, the best type of controller in terms of error and control current has been selected. Finally, this controller is implemented on the experimental data of the patient's movements, and the control current is calculated to achieve the desired torque and motion.Keywords: rehabilitation, magnetorheological fluid, knee, brake, adaptive control, robust control, neural network control, torque control
Procedia PDF Downloads 1513942 Grandiose Narcissists’ Adaptive Trade-Offs: Mating, Parental, and Somatic Investment
Authors: Jasmine H. Gagnon
Abstract:
The present study examined how grandiose narcissists make adaptive trade-offs between mating investment, parenting investment, and somatic investment relative to individuals without narcissistic personalities. A sample of 509 males and females between the ages of 24 and 35 years old (49.31% female) completed a personality inventory assessing Honesty-Humility, Emotionality, Extraversion, Agreeableness, Conscientiousness, and Openness to Experience. In a Latent Profile Analysis (LPA), personality inventory scores were used to classify participants into latent groups. The model of best fit identified one grandiose narcissist group and three groups with non-narcissistic personalities. Covariate analyses revealed that individuals with narcissistic traits made significantly more significant somatic investments in comparison to two of the three non-narcissistic latent groups. No other significant differences between the narcissistic and non-pathological groups were found. Thus, grandiose narcissists trade off parenting and mating investments to make more significant somatic investments. That is, they expend a larger portion of their energetic resources on maintaining their physical health and careers and similar quantities of energetic resources on maintaining relationships with their offspring and potential romantic partners as individuals without narcissistic personalities.Keywords: narcissism, grandiose narcissism, HEXACO, trade-offs, mating, parenting, somatic, dark triad
Procedia PDF Downloads 823941 Cognitive Development Theories as Determinant of Children's Brand Recall and Ad Recognition: An Indian Perspective
Authors: Ruchika Sharma
Abstract:
In the past decade, there has been an explosion of research that has examined children’s understanding of TV advertisements and its persuasive intent, socialization of child consumer and child psychology. However, it is evident from the literature review that no studies in this area have covered advertising messages and its impact on children’s brand recall and ad recognition. Copywriters use various creative devices to lure the consumers and very impressionable consumers such as children face far more drastic effects of these creative ways of persuasion. On the basis of Piaget’s theory of cognitive development as a theoretical basis for predicting/understanding children’s response and understanding, a quasi-experiment was carried out for the study, that manipulated measurement timing and advertising messages (familiar vs. unfamiliar) keeping gender and age group as two prominent factors. This study also examines children’s understanding of Advertisements and its elements, predominantly - Language, keeping in view Fishbein’s model. Study revealed significant associations between above mentioned factors and children’s brand recall and ad identification. Further, to test the reliability of the findings on larger sample, bootstrap simulation technique was used. The simulation results are in accordance with the findings of experiment, suggesting that the conclusions obtained from the study can be generalized for entire children’s (as consumers) market in India.Keywords: advertising, brand recall, cognitive development, preferences
Procedia PDF Downloads 2913940 Research on Resilience-Oriented Disintegration in System-of-System
Authors: Hang Yang, Jiahao Liu, Jichao Li, Kewei Yang, Minghao Li, Bingfeng Ge
Abstract:
The system-of-systems (SoS) are utilized to characterize networks formed by integrating individual complex systems that demonstrate interdependence and interconnectedness. Research on the disintegration issue in SoS is significant in improving network survivability, maintaining network security, and optimizing SoS architecture. Accordingly, this study proposes an integrated framework called resilience-oriented disintegration in SoS (SoSRD), for modeling and solving the issue of SoS disintegration. Firstly, a SoS disintegration index (SoSDI) is presented to evaluate the disintegration effect of SoS. This index provides a practical description of the disintegration process and is the first integration of the network disintegration model and resilience models. Subsequently, we propose a resilience-oriented disintegration method based on reinforcement learning (RDRL) to enhance the efficiency of SoS disintegration. This method is not restricted by the problem scenario as well as considering the coexistence of disintegration (node/link removal) and recovery (node/link addition) during the process of SoS disintegration. Finally, the effectiveness and superiority of the proposed SoSRD are demonstrated through a case study. We demonstrate that our proposed framework outperforms existing indexes and methods in both node and link disintegration scenarios, providing a fresh perspective on network disintegration. The findings provide crucial insights into dismantling harmful SoS and designing a more resilient SoS.Keywords: system-of-systems, disintegration index, resilience, reinforcement learning
Procedia PDF Downloads 163939 Clinical Factors of Quality Switched Ruby Laser Therapy for Lentigo Depigmentation
Authors: SunWoo Lee, TaeBum Lee, YoonHwa Park, YooJeong Kim
Abstract:
Solar lentigines appear predominantly on chronically sun-exposed areas of skin, such as the face and the back of the hands. Among the several ways to lentigines treatment, quality-switched lasers are well-known effective treatment for removing solar lentigines. The present pilot study was therefore designed to assess the efficacy of quality-switched ruby laser treatment of such lentigines compare between pretreatment and posttreatment of skin brightness. Twenty-two adults with chronic sun-damaged skin (mean age 52.8 years, range 37–74 years) were treated at the Korean site. A 694 nm Q-switched ruby laser was used, with the energy density set from 1.4 to 12.5 J/cm2, to treat solar lentigines. Average brightness of skin color before ruby laser treatment was 137.3 and its skin color was brightened after ruby laser treatment by 150.5. Also, standard deviation of skin color was decreased from 17.8 to 16.4. Regarding the multivariate model, age and energy were identified as significant factors for skin color brightness change in lentigo depigmentation by ruby laser treatment. Their respective odds ratios were 1.082 (95% CI, 1.007–1.163), and 1.431 (95% CI, 1.051–1.946). Lentigo depigmentation treatment using ruby lasers resulted in a high performance in skin color brightness. Among the relative factors involve with ruby laser treatment, age and energy were the most effective factors which skin color change to brighter than pretreatment.Keywords: depigmentation, lentigine, quality switched ruby laser, skin color
Procedia PDF Downloads 2513938 Evaluation of the Internal Quality for Pineapple Based on the Spectroscopy Approach and Neural Network
Authors: Nonlapun Meenil, Pisitpong Intarapong, Thitima Wongsheree, Pranchalee Samanpiboon
Abstract:
In Thailand, once pineapples are harvested, they must be classified into two classes based on their sweetness: sweet and unsweet. This paper has studied and developed the assessment of internal quality of pineapples using a low-cost compact spectroscopy sensor according to the Spectroscopy approach and Neural Network (NN). During the experiments, Batavia pineapples were utilized, generating 100 samples. The extracted pineapple juice of each sample was used to determine the Soluble Solid Content (SSC) labeling into sweet and unsweet classes. In terms of experimental equipment, the sensor cover was specifically designed to install the sensor and light source to read the reflectance at a five mm depth from pineapple flesh. By using a spectroscopy sensor, data on visible and near-infrared reflectance (Vis-NIR) were collected. The NN was used to classify the pineapple classes. Before the classification step, the preprocessing methods, which are Class balancing, Data shuffling, and Standardization were applied. The 510 nm and 900 nm reflectance values of the middle parts of pineapples were used as features of the NN. With the Sequential model and Relu activation function, 100% accuracy of the training set and 76.67% accuracy of the test set were achieved. According to the abovementioned information, using a low-cost compact spectroscopy sensor has achieved favorable results in classifying the sweetness of the two classes of pineapples.Keywords: neural network, pineapple, soluble solid content, spectroscopy
Procedia PDF Downloads 773937 Kinetics, Equilibrium and Thermodynamic Studies on Adsorption of Reactive Blue 29 from Aqueous Solution Using Activated Tamarind Kernel Powder
Authors: E. D. Paul, A. D. Adams, O. Sunmonu, U. S. Ishiaku
Abstract:
Activated tamarind kernel powder (ATKP) was prepared from tamarind fruit (Tamarindus indica), and utilized for the removal of Reactive Blue 29 (RB29) from its aqueous solution. The powder was activated using 4N nitric acid (HNO₃). The adsorbent was characterised using infrared spectroscopy, bulk density, ash content, pH, moisture content and dry matter content measurements. The effect of various parameters which include; temperature, pH, adsorbent dosage, ion concentration, and contact time were studied. Four different equilibrium isotherm models were tested on the experimental data, but the Temkin isotherm model was best-fitted into the experimental data. The pseudo-first order and pseudo-second-order kinetic models were also fitted into the graphs, but pseudo-second order was best fitted to the experimental data. The thermodynamic parameters showed that the adsorption of Reactive Blue 29 onto activated tamarind kernel powder is a physical process, feasible and spontaneous, exothermic in nature and there is decreased randomness at the solid/solution interphase during the adsorption process. Therefore, activated tamarind kernel powder has proven to be a very good adsorbent for the removal of Reactive Blue 29 dyes from industrial waste water.Keywords: tamarind kernel powder, reactive blue 29, isotherms, kinetics
Procedia PDF Downloads 2483936 Flexural Behavior of Composite Hybrid Beam Models Combining Steel Inverted T-Section and RC Flange
Authors: Abdul Qader Melhem, Hacene Badache
Abstract:
This paper deals with the theoretical and experimental study of shear connection via simple steel reinforcement shear connectors, which are steel reinforcing bars bent into L-shapes, instead of commonly used headed studs. This suggested L-shape connectors are readily available construction material in steel reinforcement. The composite section, therefore, consists of steel inverted T-section being embedded within a lightly reinforced concrete flange at the top slab as a unit. It should be noted that the cross section of these composite models involves steel inverted T-beam, replacing the steel top flange of a standard commonly employed I-beam section. The paper concentrates on the elastic and elastic-plastic behavior of these composite models. Failure modes either by cracking of concrete or shear connection be investigated in details. Elastic and elastoplastic formulas of the composite model have been computed for different locations of NA. Deflection formula has been derived, its value was close to the test value. With a supportive designing curve, this curve is valuable for both designing engineers and researchers. Finally, suggested designing curves and valuable equations will be presented. A check is made between theoretical and experimental outcomes.Keywords: composite, elastic-plastic, failure, inverted T-section, L-Shape connectors
Procedia PDF Downloads 2273935 Understanding the Selectional Preferences of the Twitter Mentions Network
Authors: R. Sudhesh Solomon, P. Y. K. L. Srinivas, Abhay Narayan, Amitava Das
Abstract:
Users in social networks either unicast or broadcast their messages. At mention is the popular way of unicasting for Twitter whereas general tweeting could be considered as broadcasting method. Understanding the information flow and dynamics within a Social Network and modeling the same is a promising and an open research area called Information Diffusion. This paper seeks an answer to a fundamental question - understanding if the at-mention network or the unicasting pattern in social media is purely random in nature or is there any user specific selectional preference? To answer the question we present an empirical analysis to understand the sociological aspects of Twitter mentions network within a social network community. To understand the sociological behavior we analyze the values (Schwartz model: Achievement, Benevolence, Conformity, Hedonism, Power, Security, Self-Direction, Stimulation, Traditional and Universalism) of all the users. Empirical results suggest that values traits are indeed salient cue to understand how the mention-based communication network functions. For example, we notice that individuals possessing similar values unicast among themselves more often than with other value type people. We also observe that traditional and self-directed people do not maintain very close relationship in the network with the people of different values traits.Keywords: information diffusion, personality and values, social network analysis, twitter mentions network
Procedia PDF Downloads 3753934 Improving the Flow Capacity (CV) of the Valves
Authors: Pradeep A. G, Gorantla Giridhar, Vijay Turaga, Vinod Srinivasa
Abstract:
The major problem in the flow control valve is of lower Cv, which will reduce the overall efficiency of the flow circuit. Designers are continuously working to improve the Cv of the valve, but they need to validate the design ideas they have regarding the improvement of Cv. The traditional method of prototyping and testing takes a lot of time. That is where CFD comes into the picture with very quick and accurate validation along with visualization, which is not possible with the traditional testing method. We have developed a method to predict Cv value using CFD analysis by iterating on various Boundary conditions, solver settings and by carrying out grid convergence studies to establish the correlation between the CFD model and Test data. The present study investigates 3 different ideas put forward by the designers for improving the flow capacity of the valves, like reducing the cage thickness, changing the port position, and using the parabolic plug to guide the flow. Using CFD, we analyzed all design changes using the established methodology that we developed. We were able to evaluate the effect of these design changes on the Valve Cv. We optimized the wetted surface of the valve further by suggesting the design modification to the lower part of the valve to make the flow more streamlined. We could find that changing cage thickness and port position has little impact on the valve Cv. The combination of optimized wetted surface and introduction of parabolic plug improved the Flow capacity (Cv) of the valve significantly.Keywords: flow control valves, flow capacity (Cv), CFD simulations, design validation
Procedia PDF Downloads 1643933 Creep Compliance Characteristics of Cement Dust Asphalt Concrete Mixtures
Authors: Ayman Othman, Tallat Abd el Wahed
Abstract:
The current research is directed towards studying the creep compliance characteristics of asphalt concrete mixtures modified with cement dust. This study can aid in assessing the permanent deformation potential of asphalt concrete mixtures. Cement dust was added to the mixture as mineral filler and compared with regular lime stone filler. A power law model was used to characterize the creep compliance behavior of the studied mixtures. Creep testing results have revealed that the creep compliance power law parameters have a strong relationship with mixture type. Testing results of the studied mixtures, as indicated by the creep compliance parameters revealed an enhancement in the creep resistance, Marshall stability, indirect tensile strength and compressive strength for cement dust mixtures as compared to mixtures with traditional lime stone filler. It is concluded that cement dust can be successfully used to decrease the potential of asphalt concrete mixture to permanent deformation and improve its mechanical properties. This is in addition to the environmental benefits that can be gained when using cement dust in asphalt paving technology.Keywords: cement dust, asphalt concrete mixtures, creep compliance, Marshall stability, indirect tensile strength, compressive strength
Procedia PDF Downloads 4273932 Well-Being Inequality Using Superimposing Satisfaction Waves: Heisenberg Uncertainty in Behavioral Economics and Econometrics
Authors: Okay Gunes
Abstract:
In this article, for the first time in the literature for this subject we propose a new method for the measuring of well-being inequality through a model composed of superimposing satisfaction waves. The displacement of households’ satisfactory state (i.e. satisfaction) is defined in a satisfaction string. The duration of the satisfactory state for a given period of time is measured in order to determine the relationship between utility and total satisfactory time, itself dependent on the density and tension of each satisfaction string. Thus, individual cardinal total satisfaction values are computed by way of a one-dimensional form for scalar sinusoidal (harmonic) moving wave function, using satisfaction waves with varying amplitudes and frequencies which allow us to measure well-being inequality. One advantage to using satisfaction waves is the ability to show that individual utility and consumption amounts would probably not commute; hence it is impossible to measure or to know simultaneously the values of these observables from the dataset. Thus, we crystallize the problem by using a Heisenberg-type uncertainty resolution for self-adjoint economic operators. We propose to eliminate any estimation bias by correlating the standard deviations of selected economic operators; this is achieved by replacing the aforementioned observed uncertainties with households’ perceived uncertainties (i.e. corrected standard deviations) obtained through the logarithmic psychophysical law proposed by Weber and Fechner.Keywords: Heisenberg uncertainty principle, superimposing satisfaction waves, Weber–Fechner law, well-being inequality
Procedia PDF Downloads 4413931 Bridging Stress Modeling of Composite Materials Reinforced by Fiber Using Discrete Element Method
Authors: Chong Wang, Kellem M. Soares, Luis E. Kosteski
Abstract:
The problem of toughening in brittle materials reinforced by fibers is complex, involving all the mechanical properties of fibers, matrix, the fiber/matrix interface, as well as the geometry of the fiber. An appropriate method applicable to the simulation and analysis of toughening is essential. In this work, we performed simulations and analysis of toughening in brittle matrix reinforced by randomly distributed fibers by means of the discrete elements method. At first, we put forward a mechanical model of the contribution of random fibers to the toughening of composite. Then with numerical programming, we investigated the stress, damage and bridging force in the composite material when a crack appeared in the brittle matrix. From the results obtained, we conclude that: (i) fibers with high strength and low elasticity modulus benefit toughening; (ii) fibers with relatively high elastic modulus compared to the matrix may result in considerable matrix damage (spalling effect); (iii) employment of high-strength synthetic fiber is a good option. The present work makes it possible to optimize the parameters in order to produce advanced ceramic with desired performance. We believe combination of the discrete element method (DEM) with the finite element method (FEM) can increase the versatility and efficiency of the software developed.Keywords: bridging stress, discrete element method, fiber reinforced composites, toughening
Procedia PDF Downloads 4453930 Disposition Kinetics of Ciprofloxacin after Intramuscular Administration in Lohi Sheep
Authors: Zahid Iqbal, Ijaz Javed, Riaz Hussain, Ibadullah Jan, Amir Ali Khan
Abstract:
This study was conducted to investigate the disposition kinetics of ciprofloxacin and calculate its optimal dosage in Pakistani sheep of Lohi breed. Injectable preparation of ciprofloxacin was given intramuscularly to eight sheep at a dose of 5 mg/Kg. Before administration of drug blood sample was drawn from each animal. Post drug administration, blood samples were also drawn at various predetermined time periods. Drug concentration in the blood samples was assessed through high performance liquid chromatograph (HPLC). Data were best described by two compartment open model and different pharmacokinetic (PK) parameters were calculated. Cmax of 1.97 ± 0.15 µg/ml was reached at Tmax of 0.88 ± 0.09 hours. Half life of absorption (t1/2 abs) was observed to be 0.63 ± 0.16 hours while t1/2 α (distribution half life) and t1/2 ß (elimination half life) were found to be 0.46 ± 0.05 and 2.93 ± 0.45 hours, respectively. Vd (apparent volume of distribution) was calculated as 2.89 ± 0.30 L/kg while AUC (area under the curve) was 7.19 ± 0.38 µg.hr/mL and CL (total body clearance) was 0.75 ± 0.04 L/hr/kg. Using these parameters, an optimal intramuscular dosage of ciprofloxacin in adult Lohi sheep was calculated as 21.43 mg/kg, advised to be repeated after 24 hours. From this, we came to the conclusion that calculated dose was much higher than the dose advised by the foreign manufacturer and to avoid antimicrobial resistance, it is advised that this locally investigated dosage regimen should be strictly followed in local sheep.Keywords: pharmacokinetics, dosage regimen, ciprofloxacin, HPLC, sheep
Procedia PDF Downloads 5393929 Inhibitory Impacts of Fulvic Acid-Coated Iron Oxide Nano Particles on the Amyloid Fibril Aggregations
Authors: Dalia Jomehpour, Sara Sheikhlary, Esmaeil Heydari, Mohammad Hossien Majles Ara
Abstract:
In this study, we report fulvic acid-coated iron oxide nanoparticles of 10.7 ± 2.7 nm size, which serve to inhibit amyloid fibrillation formation. Although the effect of fulvic acid on tau fibrils was investigated, to our best knowledge, its inhibitory impacts on amyloid aggregation formation have been assessed neither in-vitro nor in-vivo. On the other hand, iron oxide nanoparticles exhibit anti-amyloid activity on their own. This study investigates the inhibitory effect of fulvic acid coated iron oxide nanoparticles on amyloid aggregations formed from the commonly used in-vitro model, lysozyme from chicken egg white. FESEM, XRD, and FTIR characterization confirmed that fulvic acid was coated onto the surface of the nanoparticles. The inhibitory effects of the fulvic acid coated iron oxide nanoparticles were verified by Thioflavin T assay, circular dichroism (CD), and FESEM analysis. Furthermore, the toxicity of the nanoparticles on the neuroblastoma SH-SY5Y human cell line was assessed through an MTT assay. Our results indicate that fulvic acid coated iron oxide nanoparticles can efficiently inhibit the formation of amyloid aggregations while exhibiting negligible in-vitro toxicity; thus, they can be used as anti-amyloid agents in the development of the potential drug for neurodegenerative diseases.Keywords: Alzheimer’s disease, fulvic acid coated iron oxide nanoparticles, fulvic acid, amyloid inhibitor, polyphenols
Procedia PDF Downloads 1123928 All Types of Base Pair Substitutions Induced by γ-Rays in Haploid and Diploid Yeast Cells
Authors: Natalia Koltovaya, Nadezhda Zhuchkina, Ksenia Lyubimova
Abstract:
We study the biological effects induced by ionizing radiation in view of therapeutic exposure and the idea of space flights beyond Earth's magnetosphere. In particular, we examine the differences between base pair substitution induction by ionizing radiation in model haploid and diploid yeast Saccharomyces cerevisiae cells. Such mutations are difficult to study in higher eukaryotic systems. In our research, we have used a collection of six isogenic trp5-strains and 14 isogenic haploid and diploid cyc1-strains that are specific markers of all possible base-pair substitutions. These strains differ from each other only in single base substitutions within codon-50 of the trp5 gene or codon-22 of the cyc1 gene. Different mutation spectra for two different haploid genetic trp5- and cyc1-assays and different mutation spectra for the same genetic cyc1-system in cells with different ploidy — haploid and diploid — have been obtained. It was linear function for dose-dependence in haploid and exponential in diploid cells. We suggest that the differences between haploid yeast strains reflect the dependence on the sequence context, while the differences between haploid and diploid strains reflect the different molecular mechanisms of mutations.Keywords: base pair substitutions, γ-rays, haploid and diploid cells, yeast Saccharomyces cerevisiae
Procedia PDF Downloads 1553927 Simulation of Improving the Efficiency of a Fire-Tube Steam Boiler
Authors: Roudane Mohamed
Abstract:
In this study we are interested in improving the efficiency of a steam boiler to 4.5T/h and minimize fume discharge temperature by the addition of a heat exchanger against the current in the energy system, the output of the boiler. The mathematical approach to the problem is based on the use of heat transfer by convection and conduction equations. These equations have been chosen because of their extensive use in a wide range of application. A software and developed for solving the equations governing these phenomena and the estimation of the thermal characteristics of boiler through the study of the thermal characteristics of the heat exchanger by both LMTD and NUT methods. Subsequently, an analysis of the thermal performance of the steam boiler by studying the influence of different operating parameters on heat flux densities, temperatures, exchanged power and performance was carried out. The study showed that the behavior of the boiler is largely influenced. In the first regime (P = 3.5 bar), the boiler efficiency has improved significantly from 93.03 to 99.43 at the rate of 6.47% and 4.5%. For maximum speed, the change is less important, it is of the order of 1.06%. The results obtained in this study of great interest to industrial utilities equipped with smoke tube boilers for the preheating air temperature intervene to calculate the actual temperature of the gas so the heat exchanged will be increased and minimize temperature smoke discharge. On the other hand, this work could be used as a model of computation in the design process.Keywords: numerical simulation, efficiency, fire tube, heat exchanger, convection and conduction
Procedia PDF Downloads 2183926 On the Allopatry of National College Entrance Exam in China: The Root, Policy and Strategy
Authors: Shi Zhang
Abstract:
This paper aims to introduce the allopatry of national college entrance examination which allow migrant students enter senior high schools and take college entrance exam where they live, identifies the reasons affect the implementation of this policy in the Chinese context. Most of China’s provinces and municipalities recently have announced new policies regarding national college entrance exams for non-local students. The paper conducts SWOT analysis reveals the opportunities, strength, weakness and challenges of the scheme, so as to discuss the implementation strategies from the perspectives of idea and institution. The research findings imply that the government should take a more positive attitude toward relaxing the allopatry of NCEE policy restrictions, and promote the reform household registration policy and NCEE policy with synchronous operations. Higher education institutions should explore the diversification of enrollment model; the government should issue the authority of universities and colleges to select elite migrant students beyond the restrictions of NCEE. To suit reform policies to local conditions, the big cities such as Beijing, Shanghai and Guangzhou should publish related compensate measures for children of migrant workers access to higher vocational colleges with tuition fee waivered.Keywords: college entrance examination, higher education, education policy, education equality
Procedia PDF Downloads 3773925 Comparative Sustainability Performance Analysis of Australian Companies Using Composite Measures
Authors: Ramona Zharfpeykan, Paul Rouse
Abstract:
Organizational sustainability is important to both organizations themselves and their stakeholders. Despite its increasing popularity and increasing numbers of organizations reporting sustainability, research on evaluating and comparing the sustainability performance of companies is limited. The aim of this study was to develop models to measure sustainability performance for both cross-sectional and longitudinal comparisons across companies in the same or different industries. A secondary aim was to see if sustainability reports can be used to evaluate sustainability performance. The study used both a content analysis of Australian sustainability reports in mining and metals and financial services for 2011-2014 and a survey of Australian and New Zealand organizations. Two methods ranging from a composite index using uniform weights to data envelopment analysis (DEA) were employed to analyze the data and develop the models. The results show strong statistically significant relationships between the developed models, which suggests that each model provides a consistent, systematic and reasonably robust analysis. The results of the models show that for both industries, companies that had sustainability scores above or below the industry average stayed almost the same during the study period. These indices and models can be used by companies to evaluate their sustainability performance and compare it with previous years, or with other companies in the same or different industries. These methods can also be used by various stakeholders and sustainability ranking companies such as the Global Reporting Initiative (GRI).Keywords: data envelopment analysis, sustainability, sustainability performance measurement system, sustainability performance index, global reporting initiative
Procedia PDF Downloads 1813924 Renewable Energy Utilization for Future Sustainability: An Approach to Roof-Mounted Photovoltaic Array Systems and Domestic Rooftop Rainwater Harvesting System Implementation in a Himachal Pradesh, India
Authors: Rajkumar Ghosh, Ananya Mukhopadhyay
Abstract:
This scientific paper presents a thorough investigation into the integration of roof-mounted photovoltaic (PV) array systems and home rooftop rainwater collection systems in a remote community in Himachal Pradesh, India, with the goal of optimum utilization of natural resources for attaining sustainable living conditions by 2030. The study looks into the technical feasibility, environmental benefits, and socioeconomic impacts of this integrated method, emphasizing its ability to handle energy and water concerns in remote rural regions. This comprehensive method not only provides a sustainable source of electricity but also ensures a steady supply of clean water, promoting resilience and improving the quality of life for the village's residents. This research highlights the potential of such integrated systems in supporting sustainable conditions in rural areas through a combination of technical feasibility studies, economic analysis, and community interaction. There would be 20690 villages and 1.48 million homes (23.79% annual growth rate) in Himachal Pradesh if all residential buildings in the state had roof-mounted photovoltaic arrays to capture solar energy for power generation. The energy produced is utilized to power homes, lessening dependency on traditional fossil fuels. The same residential buildings housed domestic rooftop rainwater collection systems. Rainwater runoff from rooftops is collected and stored in tanks for use in a number of residential purposes, such as drinking, cooking, and irrigation. The gathered rainfall enhances the region's limited groundwater resources, easing the strain on local wells and aquifers. Although Himachal Pradesh of India is a Power state, the PV arrays have reduced the reliance of village on grid power and diesel generators by providing a steady source of electricity. Rooftop rainwater gathering has not only increased residential water supply but it has also lessened the burden on local groundwater resources. This helps to replenish groundwater and offers a more sustainable water supply for the town. The neighbourhood has saved money by utilizing renewable energy and rainwater gathering. Furthermore, lower fossil fuel consumption reduces greenhouse gas emissions, which helps to mitigate the effects of climate change. The integrated strategy of installing grid connected rooftop photovoltaic arrays and home rooftop rainwater collecting systems in Himachal Pradesh rural community demonstrates a feasible model for sustainable development. According to “Swaran Jayanti Energy Policy of Himachal Pradesh”, Himachal Pradesh is planned 10 GW from rooftop mode from Solar Power. Government of India provides 40% subsidy on solar panel of 1-3 kw and subsidy of Rs 6,000 per kw per year to encourage domestic consumers of Himachal Pradesh. This effort solves energy and water concerns, improves economic well-being, and helps to conserve the environment. Such integrated systems can serve as a model for sustainable development in rural areas not only in Himachal Pradesh, but also in other parts of the world where resource scarcity is a major concern. Long-term performance and scalability of such integrated systems should be the focus of future study. Efforts should also be made to duplicate this approach in other rural areas and examine its socioeconomic and environmental implications over time.Keywords: renewable energy, photovoltaic arrays, rainwater harvesting, sustainability, rural development, Himachal Pradesh, India
Procedia PDF Downloads 100