Search results for: work load
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 15525

Search results for: work load

14805 Design and Fabrication of a Smart Quadruped Robot

Authors: Shivani Verma, Amit Agrawal, Pankaj Kumar Meena, Ashish B. Deoghare

Abstract:

Over the decade robotics has been a major area of interest among the researchers and scientists in reducing human efforts. The need for robots to replace human work in different dangerous fields such as underground mining, nuclear power station and war against terrorist attack has gained huge attention. Most of the robot design is based on human structure popularly known as humanoid robots. However, the problems encountered in humanoid robots includes low speed of movement, misbalancing in structure, poor load carrying capacity, etc. The simplification and adaptation of the fundamental design principles seen in animals have led to the creation of bio-inspired robots. But the major challenges observed in naturally inspired robot include complexity in structure, several degrees of freedom and energy storage problem. The present work focuses on design and fabrication of a bionic quadruped walking robot which is based on different joint of quadruped mammals like a dog, cheetah, etc. The design focuses on the structure of the robot body which consists of four legs having three degrees of freedom per leg and the electronics system involved in it. The robot is built using readily available plastics and metals. The proposed robot is simple in construction and is able to move through uneven terrain, detect and locate obstacles and take images while carrying additional loads which may include hardware and sensors. The robot will find possible application in the artificial intelligence sector.

Keywords: artificial intelligence, bionic, quadruped robot, degree of freedom

Procedia PDF Downloads 200
14804 Smart Monitoring and Control of Tap Changer Using Intelligent Electronic Device

Authors: K. N. Dinesh Babu, M. V. Gopalan, G. R. Manjunatha, R. Ramaprabha, V. Rajini

Abstract:

In this paper, monitoring and control of tap changer mechanism of a transformer implementation in an intelligent electronic device (IED) is discussed. Its been a custom for decades to provide a separate panel for on load tap changer control for monitoring the tap position. However this facility cannot either record or transfer the information to remote control centers. As there is a technology shift towards the smart grid protection and control standards, the need for implementing remote control and monitoring has necessitated the implementation of this feature in numerical relays. This paper deals with the programming, settings and logic implementation which is applicable to both IEC 61850 compatible and non-compatible IEDs thereby eliminating the need for separate tap changer control equipment. The monitoring mechanism has been implemented in a 28MVA, 110 /6.9kV transformer with 16 tap position with GE make T60 IED at Ultratech cement limited Gulbarga, Karnataka and is in successful service.

Keywords: transformer protection, tap changer control, tap position monitoring, on load tap changer, intelligent electronic device (IED)

Procedia PDF Downloads 578
14803 Modeling of Virtual Power Plant

Authors: Muhammad Fanseem E. M., Rama Satya Satish Kumar, Indrajeet Bhausaheb Bhavar, Deepak M.

Abstract:

Keeping the right balance of electricity between the supply and demand sides of the grid is one of the most important objectives of electrical grid operation. Power generation and demand forecasting are the core of power management and generation scheduling. Large, centralized producing units were used in the construction of conventional power systems in the past. A certain level of balance was possible since the generation kept up with the power demand. However, integrating renewable energy sources into power networks has proven to be a difficult challenge due to its intermittent nature. The power imbalance caused by rising demands and peak loads is negatively affecting power quality and dependability. Demand side management and demand response were one of the solutions, keeping generation the same but altering or rescheduling or shedding completely the load or demand. However, shedding the load or rescheduling is not an efficient way. There comes the significance of virtual power plants. The virtual power plant integrates distributed generation, dispatchable load, and distributed energy storage organically by using complementing control approaches and communication technologies. This would eventually increase the utilization rate and financial advantages of distributed energy resources. Most of the writing on virtual power plant models ignored technical limitations, and modeling was done in favor of a financial or commercial viewpoint. Therefore, this paper aims to address the modeling intricacies of VPPs and their technical limitations, shedding light on a holistic understanding of this innovative power management approach.

Keywords: cost optimization, distributed energy resources, dynamic modeling, model quality tests, power system modeling

Procedia PDF Downloads 44
14802 Weaknesses and Performance Defects of Steel Structures According to the Executive Criteria

Authors: Ehsan Sadie

Abstract:

Despite the experience of heavy losses and damages of recent earthquakes such as 8 km E of Pāhala, Hawaii, 11 km W of Salvaleón de Higüey, Dominican Republic and 49 km SSE of Punta Cana, Dominican Republic earthquakes, the possibility of large earthquakes in most populated areas of any country and the serious need for quality control in the design and implementation of buildings, not enough attention has been paid to the proper construction. Steel structures constitute a significant part of construction in any metropolitan area. This article gives a brief overview of the implementation status of these buildings in urban areas and considers the weaknesses of performance that typically occur due to negligence or insufficient mastery of the building supervisor in the principles of operation of earthquake-resistant buildings, and provide appropriate and possible solutions to improve the construction.

Keywords: bracing member, concentrated load, diaphragm system, earthquake engineering, load-bearing system, shear force, seismic retrofitting, steel building, strip foundation, supervising engineer, vulnerability of building

Procedia PDF Downloads 135
14801 GBKMeans: A Genetic Based K-Means Applied to the Capacitated Planning of Reading Units

Authors: Anderson S. Fonseca, Italo F. S. Da Silva, Robert D. A. Santos, Mayara G. Da Silva, Pedro H. C. Vieira, Antonio M. S. Sobrinho, Victor H. B. Lemos, Petterson S. Diniz, Anselmo C. Paiva, Eliana M. G. Monteiro

Abstract:

In Brazil, the National Electric Energy Agency (ANEEL) establishes that electrical energy companies are responsible for measuring and billing their customers. Among these regulations, it’s defined that a company must bill your customers within 27-33 days. If a relocation or a change of period is required, the consumer must be notified in writing, in advance of a billing period. To make it easier to organize a workday’s measurements, these companies create a reading plan. These plans consist of grouping customers into reading groups, which are visited by an employee responsible for measuring consumption and billing. The creation process of a plan efficiently and optimally is a capacitated clustering problem with constraints related to homogeneity and compactness, that is, the employee’s working load and the geographical position of the consuming unit. This process is a work done manually by several experts who have experience in the geographic formation of the region, which takes a large number of days to complete the final planning, and because it’s human activity, there is no guarantee of finding the best optimization for planning. In this paper, the GBKMeans method presents a technique based on K-Means and genetic algorithms for creating a capacitated cluster that respects the constraints established in an efficient and balanced manner, that minimizes the cost of relocating consumer units and the time required for final planning creation. The results obtained by the presented method are compared with the current planning of a real city, showing an improvement of 54.71% in the standard deviation of working load and 11.97% in the compactness of the groups.

Keywords: capacitated clustering, k-means, genetic algorithm, districting problems

Procedia PDF Downloads 182
14800 OpenMP Parallelization of Three-Dimensional Magnetohydrodynamic Code FOI-PERFECT

Authors: Jiao F. Huang, Shi Chen, Shu C. Duan, Gang H. Wang

Abstract:

Due to its complex spatial structure as well as dynamic temporal evolution, an analytic solution of an X-pinch process is out of question, and numerical simulation becomes an important tool in X-pinch studies. Intrinsically, simulations of X-pinch are three-dimensional (3D) because of the specific structure of its load. Furthermore, in order to resolve both its μm-scales and ns-durations, fine spatial mesh grid and short time steps are usually adopted. The resulting large computational scales make the parallelization of codes a vital problem to be solved if any practical simulations are to be carried out. In this work, we report OpenMP parallelization of our 3D magnetohydrodynamic (MHD) code FOI-PERFECT. Results of test runs confirm that computational efficiency has been improved after parallelization, and both the sequential and parallel versions give the same physical results under the same initial conditions.

Keywords: MHD simulation, OpenMP, parallelization, X-pinch

Procedia PDF Downloads 324
14799 Optimization of Fenton Process for the Treatment of Young Municipal Leachate

Authors: Bouchra Wassate, Younes Karhat, Khadija El Falaki

Abstract:

Leachate is a source of surface water and groundwater contamination if it has not been pretreated. Indeed, due to its complex structure and its pollution load make its treatment extremely difficult to achieve the standard limits required. The objective of this work is to show the interest of advanced oxidation processes on leachate treatment of urban waste containing high concentrations of organic pollutants. The efficiency of Fenton (Fe2+ +H2O2 + H+) reagent for young leachate recovered from collection trucks household waste in the city of Casablanca, Morocco, was evaluated with the objectives of chemical oxygen demand (COD) and discoloration reductions. The optimization of certain physicochemical parameters (initial pH value, reaction time, and [Fe2+], [H2O2]/ [Fe2+] ratio) has yielded good results in terms of reduction of COD and discoloration of the leachate.

Keywords: COD removal, color removal, Fenton process, oxidation process, leachate

Procedia PDF Downloads 272
14798 Perceived Effects of Work-Family Balance on Employee’s Job Satisfaction among Extension Agents in Southwest Nigeria

Authors: B. G. Abiona, A. A. Onaseso, T. D. Odetayo, J. Yila, O. E. Fapojuwo, K. G. Adeosun

Abstract:

This study determines the perceived effects of work-family balance on employees’ job satisfaction among Extension Agents in the Agricultural Development Programme (ADP) in southwest Nigeria. A multistage sampling technique was used to select 256 respondents for the study. Data on personal characteristics, work-family balance domain, and job satisfaction were collected. The collected data were analysed using descriptive statistics, Chi-square, Pearson Product Moment Correlation (PPMC), multiple linear regression, and Student T-test. Results revealed that the mean age of the respondents was 40 years; the majority (59.3%) of the respondents were male, and slightly above half (51.6%) of the respondents had MSc as their highest academic qualification. Findings revealed that turnover intention (x ̅ = 3.20) and work-role conflict (x ̅ = 3.06) were the major perceived work-family balance domain in the studied areas. Further, the result showed that the respondents have a high (79%) level of job satisfaction. Multiple linear regression revealed that job involvement (ß=0.167, p<0.01) and work-role conflict (ß= -0.221, p<0.05) contributed significantly to employees’ level of job satisfaction. The results of the Student T-test revealed a significant difference in the perceived work-family balance domain (t = 0.43, p<0.05) between the two studied areas. The study concluded that work-role conflict among employees causes work-family imbalance and, therefore, negatively affects employees’ job satisfaction. The definition of job design among the respondents that will create a balance between work and family is highly recommended.

Keywords: work-life, conflict, job satisfaction, extension agent

Procedia PDF Downloads 72
14797 Study of the Tribological Behavior of a Sliding Contact Brass-Steel Couple with Electrical Current

Authors: C. Boubechou, A. Bouchoucha, H. Zaidi

Abstract:

The aim of this paper is to study the tribological behavior of a dynamic contact steel-brass couple with electric current. This study looks at a dry contact brass-steel couple where friction and wear are studied in terms of mechanical and electrical parameters. For this reason, a tribometer, pin-rotary disc is used in an atmospheric atmosphere. The test parameters are as follows: the normal load (5-30N), the sliding speed (0.1 to 0.5 m / s) and the electric current (3-10A). The duration of each test is 30 minutes. The experimental results show that these parameters have a significant effect on the tribological behavior of the couple studied. The discussion of results is based on observations, using an optical microscope, MEB and a profilometer, worn surfaces and interface phenomena resulting from the process of sliding contact.

Keywords: brass-steel couple, dry friction, electrical current, morphology, normal load, sliding speeds, wear

Procedia PDF Downloads 253
14796 Assessment and Optimisation of Building Services Electrical Loads for Off-Grid or Hybrid Operation

Authors: Desmond Young

Abstract:

In building services electrical design, a key element of any project will be assessing the electrical load requirements. This needs to be done early in the design process to allow the selection of infrastructure that would be required to meet the electrical needs of the type of building. The type of building will define the type of assessment made, and the values applied in defining the maximum demand for the building, and ultimately the size of supply or infrastructure required, and the application that needs to be made to the distribution network operator, or alternatively to an independent network operator. The fact that this assessment needs to be undertaken early in the design process provides limits on the type of assessment that can be used, as different methods require different types of information, and sometimes this information is not available until the latter stages of a project. A common method applied in the earlier design stages of a project, typically during stages 1,2 & 3, is the use of benchmarks. It is a possibility that some of the benchmarks applied are excessive in relation to the current loads that exist in a modern installation. This lack of accuracy is based on information which does not correspond to the actual equipment loads that are used. This includes lighting and small power loads, where the use of more efficient equipment and lighting has reduced the maximum demand required. The electrical load can be used as part of the process to assess the heat generated from the equipment, with the heat gains from other sources, this feeds into the sizing of the infrastructure required to cool the building. Any overestimation of the loads would contribute to the increase in the design load for the heating and ventilation systems. Finally, with the new policies driving the industry to decarbonise buildings, a prime example being the recently introduced London Plan, loads are potentially going to increase. In addition, with the advent of the pandemic and changes to working practices, and the adoption of electric heating and vehicles, a better understanding of the loads that should be applied will aid in ensuring that infrastructure is not oversized, as a cost to the client, or undersized to the detriment of the building. In addition, more accurate benchmarks and methods will allow assessments to be made for the incorporation of energy storage and renewable technologies as these technologies become more common in buildings new or refurbished.

Keywords: energy, ADMD, electrical load assessment, energy benchmarks

Procedia PDF Downloads 95
14795 Techno Economic Analysis for Solar PV and Hydro Power for Kafue Gorge Power Station

Authors: Elvis Nyirenda

Abstract:

This research study work was done to evaluate and propose an optimum measure to enhance the uptake of clean energy technologies such as solar photovoltaics, the study also aims at enhancing the country’s energy mix from the overdependence on hydro power which is susceptible to droughts and climate change challenges The country in the years 2015 - 2016 and 2018 - 2019 had received rainfall below average due to climate change and a shift in the weather pattern; this resulted in prolonged power outages and load shedding for more than 10 hours per day. ZESCO Limited, the utility company that owns infrastructure in the generation, transmission, and distribution of electricity (state-owned), is seeking alternative sources of energy in order to reduce the over-dependence on hydropower stations. One of the alternative sources of energy is Solar Energy from the sun. However, solar power is intermittent in nature and to smoothen the load curve, investment in robust energy storage facilities is of great importance to enhance security and reliability of electricity supply in the country. The methodology of the study looked at the historical performance of the Kafue gorge upper power station and utilised the hourly generation figures as input data for generation modelling in Homer software. The average yearly demand was derived from the available data on the system SCADA. The two dams were modelled as natural battery with the absolute state of charging and discharging determined by the available water resource and the peak electricity demand. The software Homer Energy System is used to simulate the scheme incorporating a pumped storage facility and Solar photovoltaic systems. The pumped hydro scheme works like a natural battery for the conservation of water, with the only losses being evaporation and water leakages from the dams and the turbines. To address the problem of intermittency on the solar resource and the non-availability of water for hydropower generation, the study concluded that utilising the existing Hydro power stations, Kafue Gorge upper and Kafue Gorge Lower to work conjunctively with Solar energy will reduce power deficits and increase the security of supply for the country. An optimum capacity of 350MW of solar PV can be integrated while operating Kafue Gorge power station in both generating and pumping mode to enable efficient utilisation of water at Kafue Gorge upper Dam and Kafue Gorge Lower dam.

Keywords: hydropower, solar power systems, energy storage, photovoltaics, solar irradiation, pumped hydro storage system, supervisory control and data acquisition, Homer energy

Procedia PDF Downloads 100
14794 Using 3-Glycidoxypropyltrimethoxysilane Functionalized Silica Nanoparticles to Improve Flexural Properties of E-Glass/Epoxy Grid-Stiffened Composite Panels

Authors: Reza Eslami-Farsani, Hamed Khosravi, Saba Fayazzadeh

Abstract:

Lightweight and efficient structures have the aim to enhance the efficiency of the components in various industries. Toward this end, composites are one of the most widely used materials because of durability, high strength and modulus, and low weight. One type of the advanced composites is grid-stiffened composite (GSC) structures which have been extensively considered in aerospace, automotive, and aircraft industries. They are one of the top candidates for replacing some of the traditional components which are used here. Although there are a good number of published surveys on the design aspects and fabrication of GSC structures, little systematic work has been reported on their material modification to improve their properties, to our knowledge. Matrix modification using nanoparticles is an effective method to enhance the flexural properties of the fibrous composites. In the present study, a silane coupling agent (3-glycidoxypropyltrimethoxysilane/3-GPTS) was introduced onto the silica (SiO2) nanoparticle surface and its effects on the three-point flexural response of isogrid E-glass/epoxy composites were assessed. Based on the fourier transform infrared spectrometer (FTIR) spectra, it was inferred that the 3-GPTS coupling agent was successfully grafted onto the surface of SiO2 nanoparticles after modification. Flexural test revealed an improvement of 16%, 14%, and 36% in stiffness, maximum load and energy absorption of the isogrid specimen filled with 3 wt.% 3-GPTS/SiO2 compared to the neat one. It would be worth mentioning that in these structures, a considerable energy absorption was observed after the primary failure related to the load peak. Also, 3-GPTMS functionalization had a positive effect on the flexural behavior of the multiscale isogrid composites. In conclusion, this study suggests that the addition of modified silica nanoparticles is a promising method to improve the flexural properties of the grid-stiffened fibrous composite structures.

Keywords: isogrid-stiffened composite panels, silica nanoparticles, surface modification, flexural properties, energy absorption

Procedia PDF Downloads 231
14793 A Dual-Mode Infinite Horizon Predictive Control Algorithm for Load Tracking in PUSPATI TRIGA Reactor

Authors: Mohd Sabri Minhat, Nurul Adilla Mohd Subha

Abstract:

The PUSPATI TRIGA Reactor (RTP), Malaysia reached its first criticality on June 28, 1982, with power capacity 1MW thermal. The Feedback Control Algorithm (FCA) which is conventional Proportional-Integral (PI) controller, was used for present power control method to control fission process in RTP. It is important to ensure the core power always stable and follows load tracking within acceptable steady-state error and minimum settling time to reach steady-state power. At this time, the system could be considered not well-posed with power tracking performance. However, there is still potential to improve current performance by developing next generation of a novel design nuclear core power control. In this paper, the dual-mode predictions which are proposed in modelling Optimal Model Predictive Control (OMPC), is presented in a state-space model to control the core power. The model for core power control was based on mathematical models of the reactor core, OMPC, and control rods selection algorithm. The mathematical models of the reactor core were based on neutronic models, thermal hydraulic models, and reactivity models. The dual-mode prediction in OMPC for transient and terminal modes was based on the implementation of a Linear Quadratic Regulator (LQR) in designing the core power control. The combination of dual-mode prediction and Lyapunov which deal with summations in cost function over an infinite horizon is intended to eliminate some of the fundamental weaknesses related to MPC. This paper shows the behaviour of OMPC to deal with tracking, regulation problem, disturbance rejection and caters for parameter uncertainty. The comparison of both tracking and regulating performance is analysed between the conventional controller and OMPC by numerical simulations. In conclusion, the proposed OMPC has shown significant performance in load tracking and regulating core power for nuclear reactor with guarantee stabilising in the closed-loop.

Keywords: core power control, dual-mode prediction, load tracking, optimal model predictive control

Procedia PDF Downloads 146
14792 Experimental Studies of the Reverse Load-Unloading Effect on the Mechanical, Linear and Nonlinear Elastic Properties of n-AMg6/C60 Nanocomposite

Authors: Aleksandr I. Korobov, Natalia V. Shirgina, Aleksey I. Kokshaiskiy, Vyacheslav M. Prokhorov

Abstract:

The paper presents the results of an experimental study of the effect of reverse mechanical load-unloading on the mechanical, linear, and nonlinear elastic properties of n-AMg6/C60 nanocomposite. Samples for experimental studies of n-AMg6/C60 nanocomposite were obtained by grinding AMg6 polycrystalline alloy in a planetary mill with 0.3 wt % of C60 fullerite in an argon atmosphere. The resulting product consisted of 200-500-micron agglomerates of nanoparticles. X-ray coherent scattering (CSL) method has shown that the average nanoparticle size is 40-60 nm. The resulting preform was extruded at high temperature. Modifications of C60 fullerite interferes the process of recrystallization at grain boundaries. In the samples of n-AMg6/C60 nanocomposite, the load curve is measured: the dependence of the mechanical stress σ on the strain of the sample ε under its multi-cycle load-unloading process till its destruction. The hysteresis dependence σ = σ(ε) was observed, and insignificant residual strain ε < 0.005 were recorded. At σ≈500 MPa and ε≈0.025, the sample was destroyed. The destruction of the sample was fragile. Microhardness was measured before and after destruction of the sample. It was found that the loading-unloading process led to an increase in its microhardness. The effect of the reversible mechanical stress on the linear and nonlinear elastic properties of the n-AMg6/C60 nanocomposite was studied experimentally by ultrasonic method on the automated complex Ritec RAM-5000 SNAP SYSTEM. In the n-AMg6/C60 nanocomposite, the velocities of the longitudinal and shear bulk waves were measured with the pulse method, and all the second-order elasticity coefficients and their dependence on the magnitude of the reversible mechanical stress applied to the sample were calculated. Studies of nonlinear elastic properties of the n-AMg6/C60 nanocomposite at reversible load-unloading of the sample were carried out with the spectral method. At arbitrary values of the strain of the sample (up to its breakage), the dependence of the amplitude of the second longitudinal acoustic harmonic at a frequency of 2f = 10MHz on the amplitude of the first harmonic at a frequency f = 5MHz of the acoustic wave is measured. Based on the results of these measurements, the values of the nonlinear acoustic parameter in the n-AMg6/C60 nanocomposite sample at different mechanical stress were determined. The obtained results can be used in solid-state physics, materials science, for development of new techniques for nondestructive testing of structural materials using methods of nonlinear acoustic diagnostics. This study was supported by the Russian Science Foundation (project №14-22-00042).

Keywords: nanocomposite, generation of acoustic harmonics, nonlinear acoustic parameter, hysteresis

Procedia PDF Downloads 133
14791 Effective Width of Reinforced Concrete U-Shaped Walls Due to Shear Lag Effects

Authors: Ryan D. Hoult

Abstract:

The inherent assumption in the elementary theory of bending that plane sections remain plane is commonly used in the design of reinforced concrete members. However, in reality, a shear flow would develop in non-rectangular sections, where the longitudinal strains in between the web and flanges of the element would lag behind those at the boundary ends. This phenomenon, known as shear lag, can significantly reduce the expected moment capacity of non-rectangular reinforced concrete walls. This study focuses on shear lag effects in reinforced concrete U-shaped walls, which are commonly used as lateral load resisting elements in reinforced concrete buildings. An extensive number of finite element modelling analyses are conducted to estimate the vertical strain distributions across the web and flanges of a U-shaped wall with different axial load ratios and longitudinal reinforcement detailing. The results show that shear lag effects are prominent and sometimes significant in U-shaped walls, particularly for the wall sections perpendicular to the direction of loading.

Keywords: shear lag, walls, U-shaped, moment-curvature

Procedia PDF Downloads 188
14790 Effective Work Roll Cooling toward Stand Reduction in Hot Strip Process

Authors: Temsiri Sapsaman, Anocha Bhocarattanahkul

Abstract:

The maintenance of work rolls in hot strip processing has been lengthy and difficult tasks for hot strip manufacturer because heavy work rolls have to be taken out of the production line, which could take hours. One way to increase the time between maintenance is to improve the effectiveness of the work roll cooling system such that the wear and tear more slowly occurs, while the operation cost is kept low. Therefore, this study aims to improve the work roll cooling system by providing the manufacturer the relationship between the work-roll temperature reduced by cooling and the water flow that can help manufacturer determining the more effective water flow of the cooling system. The relationship is found using simulation with a systematic process adjustment so that the satisfying quality of product is achieved. Results suggest that the manufacturer could reduce the water flow by 9% with roughly the same performance. With the same process adjustment, the feasibility of finishing-mill-stand reduction is also investigated. Results suggest its possibility.

Keywords: work-roll cooling system, hot strip process adjustment, feasibility study, stand reduction

Procedia PDF Downloads 354
14789 Using 3-Glycidoxypropyltrimethoxysilane Functionalized SiO2 Nanoparticles to Improve Flexural Properties of Glass Fibers/Epoxy Grid-Stiffened Composite Panels

Authors: Reza Eslami-Farsani, Hamed Khosravi, Saba Fayazzadeh

Abstract:

Lightweight and efficient structures have the aim to enhance the efficiency of the components in various industries. Toward this end, composites are one of the most widely used materials because of durability, high strength and modulus, and low weight. One type of the advanced composites is grid-stiffened composite (GSC) structures, which have been extensively considered in aerospace, automotive, and aircraft industries. They are one of the top candidates for replacing some of the traditional components, which are used here. Although there are a good number of published surveys on the design aspects and fabrication of GSC structures, little systematic work has been reported on their material modification to improve their properties, to our knowledge. Matrix modification using nanoparticles is an effective method to enhance the flexural properties of the fibrous composites. In the present study, a silane-coupling agent (3-glycidoxypropyltrimethoxysilane/3-GPTS) was introduced onto the silica (SiO2) nanoparticle surface and its effects on the three-point flexural response of isogrid E-glass/epoxy composites were assessed. Based on the fourier transform infrared spectrometer (FTIR) spectra, it was inferred that the 3-GPTS coupling agent was successfully grafted onto the surface of SiO2 nanoparticles after modification. Flexural test revealed an improvement of 16%, 14%, and 36% in stiffness, maximum load and energy absorption of the isogrid specimen filled with 3 wt.% 3-GPTS/SiO2 compared to the neat one. It would be worth mentioning that in these structures, considerable energy absorption was observed after the primary failure related to the load peak. In addition, 3-GPTMS functionalization had a positive effect on the flexural behavior of the multiscale isogrid composites. In conclusion, this study suggests that the addition of modified silica nanoparticles is a promising method to improve the flexural properties of the grid-stiffened fibrous composite structures.

Keywords: isogrid-stiffened composite panels, silica nanoparticles, surface modification, flexural properties

Procedia PDF Downloads 220
14788 Material Characterization and Numerical Simulation of a Rubber Bumper

Authors: Tamás Mankovits, Dávid Huri, Imre Kállai, Imre Kocsis, Tamás Szabó

Abstract:

Non-linear FEM calculations are indispensable when important technical information like operating performance of a rubber component is desired. Rubber bumpers built into air-spring structures may undergo large deformations under load, which in itself shows non-linear behavior. The changing contact range between the parts and the incompressibility of the rubber increases this non-linear behavior further. The material characterization of an elastomeric component is also a demanding engineering task. In this paper, a comprehensive investigation is introduced including laboratory measurements, mesh density analysis and complex finite element simulations to obtain the load-displacement curve of the chosen rubber bumper. Contact and friction effects are also taken into consideration. The aim of this research is to elaborate an FEM model which is accurate and competitive for a future shape optimization task.

Keywords: rubber bumper, finite element analysis, compression test, Mooney-Rivlin material model

Procedia PDF Downloads 493
14787 Study on the Work-Life Balance of Selected Working Single Mothers in the Coastal Community of La Huerta, Paranaque

Authors: Idette Sheirina Biyo, Rhodora Lynn C. Lintag

Abstract:

This paper explores how the work-life balance of selected working single mothers situated in a coastal community is affecting their well-being. Working single mothers carry the responsibility of earning for their family while simultaneously exercising their motherhood. This study utilized a purposeful qualitative research through semi-structured interviews among ten working single mothers living in the coastal community of La Huerta, Parañaque in order to identify the following: a) experiences of the working single mothers, b) problems usually encountered, and c) how these problems are affecting their well-being. Dorothy Smith’s Feminist Standpoint theory is used as a theoretical lens in order to explain their work-life balance. Results have shown that despite their dual roles as the main income earners and heads of the households, they are not neglecting to care for their well-being. They consider getting sufficient rest, eating well, and going to church as forms of caring for their well-being. Other factors that affect their work-life balance include living arrangements, work hours, type of work, and income.

Keywords: coastal community, well-being, work-life balance, Working single mother

Procedia PDF Downloads 186
14786 Optimisation of Energy Harvesting for a Composite Aircraft Wing Structure Bonded with Discrete Macro Fibre Composite Sensors

Authors: Ali H. Daraji, Ye Jianqiao

Abstract:

The micro electrical devices of the wireless sensor network are continuously developed and become very small and compact with low electric power requirements using limited period life conventional batteries. The low power requirement for these devices, cost of conventional batteries and its replacement have encouraged researcher to find alternative power supply represented by energy harvesting system to provide an electric power supply with infinite period life. In the last few years, the investigation of energy harvesting for structure health monitoring has increased to powering wireless sensor network by converting waste mechanical vibration into electricity using piezoelectric sensors. Optimisation of energy harvesting is an important research topic to ensure a flowing of efficient electric power from structural vibration. The harvesting power is mainly based on the properties of piezoelectric material, dimensions of piezoelectric sensor, its position on a structure and value of an external electric load connected between sensor electrodes. Larger surface area of sensor is not granted larger power harvesting when the sensor area is covered positive and negative mechanical strain at the same time. Thus lead to reduction or cancellation of piezoelectric output power. Optimisation of energy harvesting is achieved by locating these sensors precisely and efficiently on the structure. Limited published work has investigated the energy harvesting for aircraft wing. However, most of the published studies have simplified the aircraft wing structure by a cantilever flat plate or beam. In these studies, the optimisation of energy harvesting was investigated by determination optimal value of an external electric load connected between sensor electrode terminals or by an external electric circuit or by randomly splitting piezoelectric sensor to two segments. However, the aircraft wing structures are complex than beam or flat plate and mostly constructed from flat and curved skins stiffened by stringers and ribs with more complex mechanical strain induced on the wing surfaces. This aircraft wing structure bonded with discrete macro fibre composite sensors was modelled using multiphysics finite element to optimise the energy harvesting by determination of the optimal number of sensors, location and the output resistance load. The optimal number and location of macro fibre sensors were determined based on the maximization of the open and close loop sensor output voltage using frequency response analysis. It was found different optimal distribution, locations and number of sensors bounded on the top and the bottom surfaces of the aircraft wing.

Keywords: energy harvesting, optimisation, sensor, wing

Procedia PDF Downloads 290
14785 Distribution Planning with Renewable Energy Units Based on Improved Honey Bee Mating Optimization

Authors: Noradin Ghadimi, Nima Amjady, Oveis Abedinia, Roza Poursoleiman

Abstract:

This paper proposed an Improved Honey Bee Mating Optimization (IHBMO) for a planning paradigm for network upgrade. The proposed technique is a new meta-heuristic algorithm which inspired by mating of the honey bee. The paradigm is able to select amongst several choices equi-cost one assuring the optimum in terms of voltage profile, considering various scenarios of DG penetration and load demand. The distributed generation (DG) has created a challenge and an opportunity for developing various novel technologies in power generation. DG prepares a multitude of services to utilities and consumers, containing standby generation, peaks chopping sufficiency, base load generation. The proposed algorithm is applied over the 30 lines, 28 buses power system. The achieved results demonstrate the good efficiency of the DG using the proposed technique in different scenarios.

Keywords: distributed generation, IHBMO, renewable energy units, network upgrade

Procedia PDF Downloads 474
14784 Optimum Design of Piled-Raft Systems

Authors: Alaa Chasib Ghaleb, Muntadher M. Abbood

Abstract:

This paper presents a study of the problem of the optimum design of piled-raft foundation systems. The study has been carried out using a hypothetic problem and soil investigations of six sites locations in Basrah city to evaluate the adequacy of using the piled-raft foundation concept. Three dimensional finite element analysis method has been used, to perform the structural analysis. The problem is optimized using Hooke and Jeeves method with the total weight of the foundation as objective function and each of raft thickness, piles length, number of piles and piles diameter as design variables. It is found that the total and differential settlement decreases with increasing the raft thickness, the number of piles, the piles length, and the piles diameter. Finally parametric study for load values, load type and raft dimensions have been studied and the results have been discussed.

Keywords: Hooke and Jeeves, optimum design, piled-raft, foundations

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14783 Trapped Versus Stepping Stones: Work Trajectories of Young Workers During the COVID-19 Pandemic

Authors: Goh Mingyuan Asher, Nurul Fadiah Johari, Neo Yu Wei, Kim Aryung, Ho Kong Chong, Irene Y. H. N. G.

Abstract:

The COVID-19 pandemic represents an externally induced force as they face a combination of reduced work, dismissal, and job change for young precarious workers. The paper drew insights from two interview waves of the in-work poverty study in Singapore which were conducted a year apart. By analysing respondents’ job histories before and at the start of the pandemic as well as their job experiences over the two waves of interviews, the study found the presence of what scholars describe as trap and stepping stone trajectories. Trap trajectories refer to how the nature of precarious employment leads respondents to be in dead-end jobs with no room for progression while stepping stone trajectories refer to how poor work provides opportunities for the accumulation of work experiences. We also look at how structure, agency and biographical factors affect job trajectories and discuss the impacts of COVID-19 on work experiences and the implications of the bifurcation of trajectory outcomes on poverty and inequality among the young working poor in Singapore.

Keywords: working poor, precarity, young workers, COVID-19, work trajectories

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14782 Finite Element Modeling Techniques of Concrete in Steel and Concrete Composite Members

Authors: J. Bartus, J. Odrobinak

Abstract:

The paper presents a nonlinear analysis 3D model of composite steel and concrete beams with web openings using the Finite Element Method (FEM). The core of the study is the introduction of basic modeling techniques comprehending the description of material behavior, appropriate elements selection, and recommendations for overcoming problems with convergence. Results from various finite element models are compared in the study. The main objective is to observe the concrete failure mechanism and its influence on the structural performance of numerical models of the beams at particular load stages. The bearing capacity of beams, corresponding deformations, stresses, strains, and fracture patterns were determined. The results show how load-bearing elements consisting of concrete parts can be analyzed using FEM software with various options to create the most suitable numerical model. The paper demonstrates the versatility of Ansys software usage for structural simulations.

Keywords: Ansys, concrete, modeling, steel

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14781 Influence of the Eccentricity of a Concentrated Load on the Behavior of Multilayers Slabs

Authors: F. Bouzeboudja, K. Ait-Tahar

Abstract:

The method of strengthening of concrete works by composite materials is a practice which knows currently an important development. From this perspective, we propose to make a contribution to the analysis of the behavior of concrete slabs reinforced with composite fabrics, arranged in parallel folds according to the thickness of the slab. The analysis of experimentally obtained modes of failure confirms, generally, that the ruin of the structure occurs essentially by punching. Accordingly, our work is directed to the analysis of the behavior of reinforced slabs towards the punching. An experimental investigation is realized. For that purpose, a set of trial specimens was made. The reinforced specimens are subjected to an essay of punching, by making vary the direction of the eccentricity. The first experimental results show that the ultimate loads, as well as the transition from the flexion failure mode to the punching failure mode, are governed essentially by the eccentricity.

Keywords: composites, concrete slabs, failure, laminate, punching

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14780 Investigating the Aerosol Load of Eastern Mediterranean Basin with Sentinel-5p Satellite

Authors: Deniz Yurtoğlu

Abstract:

Aerosols directly affect the radiative balance of the earth by absorbing and/or scattering the sun rays reaching the atmosphere and indirectly affect the balance by acting as a nucleus in cloud formation. The composition, physical, and chemical properties of aerosols vary depending on their sources and the time spent in the atmosphere. The Eastern Mediterranean Basin has a high aerosol load that is formed from different sources; such as anthropogenic activities, desert dust outbreaks, and the spray of sea salt; and the area is subjected to atmospheric transport from other locations on the earth. This region, which includes the deserts of Africa, the Middle East, and the Mediterranean sea, is one of the most affected areas by climate change due to its location and the chemistry of the atmosphere. This study aims to investigate the spatiotemporal deviation of aerosol load in the Eastern Mediterranean Basin between the years 2018-2022 with the help of a new pioneer satellite of ESA (European Space Agency), Sentinel-5P. The TROPOMI (The TROPOspheric Monitoring Instrument) traveling on this low-Earth orbiting satellite is a UV (Ultraviolet)-sensing spectrometer with a resolution of 5.5 km x 3.5 km, which can make measurements even in a cloud-covered atmosphere. By using Absorbing Aerosol Index data produced by this spectrometer and special scripts written in Python language that transforms this data into images, it was seen that the majority of the aerosol load in the Eastern Mediterranean Basin is sourced from desert dust and anthropogenic activities. After retrieving the daily data, which was separated from the NaN values, seasonal analyses match with the normal aerosol variations expected, which are high in warm seasons and lower in cold seasons. Monthly analyses showed that in four years, there was an increase in the amount of Absorbing Aerosol Index in spring and winter by 92.27% (2019-2021) and 39.81% (2019-2022), respectively. On the other hand, in the summer and autumn seasons, a decrease has been observed by 20.99% (2018-2021) and 0.94% (2018-2021), respectively. The overall variation of the mean absorbing aerosol index from TROPOMI between April 2018 to April 2022 reflects a decrease of 115.87% by annual mean from 0.228 to -0.036. However, when the data is analyzed by the annual mean values of the years which have the data from January to December, meaning from 2019 to 2021, there was an increase of 57.82% increase (0.108-0.171). This result can be interpreted as the effect of climate change on the aerosol load and also, more specifically, the effect of forest fires that happened in the summer months of 2021.

Keywords: aerosols, eastern mediterranean basin, sentinel-5p, tropomi, aerosol index, remote sensing

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14779 Transformative Learning and the Development of Cultural Humility in Social Work Students

Authors: Ruilin Zhu, Katarzyna Olcoń, Rose M. Pulliam, Dorie J. Gilbert

Abstract:

Cultural humility is increasingly important in social work literature, given its emphasis on mitigating power imbalances in helping relationships, particularly across cultural differences. Consequently, there is a need to understand whether and how cultural humility can be taught in social work education. Relying on ethnographic observations and reflective journals from a cultural immersion program, this study identified the learning process required to develop cultural humility: confusion and discomfort, re-moulding, and humility in action.

Keywords: social work education, cultural humility, transformative learning theory, study abroad, ethnographic observations

Procedia PDF Downloads 138
14778 Optimization and Energy Management of Hybrid Standalone Energy System

Authors: T. M. Tawfik, M. A. Badr, E. Y. El-Kady, O. E. Abdellatif

Abstract:

Electric power shortage is a serious problem in remote rural communities in Egypt. Over the past few years, electrification of remote communities including efficient on-site energy resources utilization has achieved high progress. Remote communities usually fed from diesel generator (DG) networks because they need reliable energy and cheap fresh water. The main objective of this paper is to design an optimal economic power supply from hybrid standalone energy system (HSES) as alternative energy source. It covers energy requirements for reverse osmosis desalination unit (DU) located in National Research Centre farm in Noubarya, Egypt. The proposed system consists of PV panels, Wind Turbines (WT), Batteries, and DG as a backup for supplying DU load of 105.6 KWh/day rated power with 6.6 kW peak load operating 16 hours a day. Optimization of HSES objective is selecting the suitable size of each of the system components and control strategy that provide reliable, efficient, and cost-effective system using net present cost (NPC) as a criterion. The harmonization of different energy sources, energy storage, and load requirements are a difficult and challenging task. Thus, the performance of various available configurations is investigated economically and technically using iHOGA software that is based on genetic algorithm (GA). The achieved optimum configuration is further modified through optimizing the energy extracted from renewable sources. Effective minimization of energy charging the battery ensures that most of the generated energy directly supplies the demand, increasing the utilization of the generated energy.

Keywords: energy management, hybrid system, renewable energy, remote area, optimization

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14777 Wind Power Mapping and NPV of Embedded Generation Systems in Nigeria

Authors: Oluseyi O. Ajayi, Ohiose D. Ohijeagbon, Mercy Ogbonnaya, Ameh Attabo

Abstract:

The study assessed the potential and economic viability of stand-alone wind systems for embedded generation, taking into account its benefits to small off-grid rural communities at 40 meteorological sites in Nigeria. A specific electric load profile was developed to accommodate communities consisting of 200 homes, a school and a community health centre. This load profile was incorporated within the distributed generation analysis producing energy in the MW range, while optimally meeting daily load demand for the rural communities. Twenty-four years (1987 to 2010) of wind speed data at a height of 10m utilized for the study were sourced from the Nigeria Meteorological Department, Oshodi. The HOMER® software optimizing tool was engaged for the feasibility study and design. Each site was suited to 3MW wind turbines in sets of five, thus 15MW was designed for each site. This design configuration was adopted in order to easily compare the distributed generation system amongst the sites to determine their relative economic viability in terms of life cycle cost, as well as levelised cost of producing energy. A net present value was estimated in terms of life cycle cost for 25 of the 40 meteorological sites. On the other hand, the remaining sites yielded a net present cost; meaning the installations at these locations were not economically viable when utilizing the present tariff regime for embedded generation in Nigeria.

Keywords: wind speed, wind power, distributed generation, cost per kilowatt-hour, clean energy, Nigeria

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14776 Vocational and Technical Educators’ Acceptance and Use of Digital Learning Environments Beyond Working Hours: Implications for Work-Life Balance and the Role of Integration Preference

Authors: Jacinta Ifeoma Obidile

Abstract:

Teachers (vocational and technical educators inclusive) use Information and Communications Technology (ICT) for tasks outside of their normal working hours. This expansion of work duties to non-work time challenges their work-life balance. However, there has been inconsistency in the results on how these relationships correlate. This, therefore, calls for further research studies to examine the moderating mechanisms of such relationships. The present study, therefore, ascertained how vocational and technical educators’ technology acceptance relates to their work-related ICT use beyond their working hours and work-life balance, as well as how their integration affects these relationships. The population of the study comprised 320 Vocational and Technical Educators from the Southeast geopolitical zone of Nigeria. Data were collected from the respondents using the structured questionnaire. The questionnaire was validated by three experts. The reliability of the study was conducted using 20 vocational and technical educators from the South who were not part of the population. The overall reliability coefficient of 0.81 was established using Cronbach’s alpha method. The data collected was analyzed using Structural equation modeling. Findings, among others, revealed that vocational and technical educators’ work-life balance was mediated by increased digital learning environment use after work hours, although reduced by social influence.

Keywords: vocational and technical educators, digital learning environment, working hours, work-life balance, integration preference

Procedia PDF Downloads 37