Search results for: outlet mass flow rate
10024 Use and Effects of Kanban Board from the Aspects of Brothers Furniture Limited
Authors: Kazi Rizvan, Yamin Rekhu
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Due to high competitiveness in industries throughout the world, every industry is trying hard to utilize all their resources to keep their productivity as high as possible. Many tools have been being used to ensure smoother flow of an operation, to balance tasks, to maintain proper schedules for tasks, to maintain proper sequence for tasks, to reduce unproductive time. All of these tools are used to augment productivity within an industry. Kanban board is one of them and of the many important tools of lean production system. Kanban Board is a visual depiction of the status of tasks. Kanban board shows the actual status of the tasks. It conveys the progress and issues of tasks as well. Using Kanban Board, tasks can be distributed among workers and operation targets can be visually represented to them. In this paper, an example of Kanban board from the aspects of Brothers Furniture Limited was taken and how the Kanban board system was implemented, how the board was designed and how it was made easily perceivable for the less literate or illiterate workers. The Kanban board was designed for the packing section of Brothers Furniture Limited. It was implemented for the purpose of representing the tasks flow to the workers and to mitigate the time that was wasted while the workers remained wondering about what task they should start after they finish one. Kanban board subsumed seven columns and there was a column for comments where if any problem occurred during working on the tasks. Kanban board was helpful for the workers as the board showed the urgency of the tasks. It was also helpful for the store section as they could understand which products and how much of them could be delivered to store at any certain time. Kanban board had all the information centralized which is why the work-flow got paced up and idle time was minimized. Regardless of many workers being illiterate or less literate, Kanban board was still explicable for the workers as the Kanban cards were colored. Since the significance of colors can be conveniently interpretable to them, colored cards helped a great deal in that matter. Hence, the illiterate or less literate workers didn’t have to spend time wondering about the significance of the cards. Even when the workers weren’t told the significance of the colored cards, they could grow a feeling about their meaning as colors can trigger anyone’s mind to perceive the situation. As a result, the board elucidated the workers about what board required them to do, when to do and what to do next. Kanban board alleviated excessive time between tasks by setting day-plan for targeted tasks and it also reduced time during tasks as the workers were acknowledged of forthcoming tasks for a day. Being very specific to the tasks, Kanban board helped the workers become more focused on their tasks helped them do their job with more perfection. As a result, The Kanban board helped achieve a 8.75% increase in productivity than the productivity before the Kanban board was implemented.Keywords: color, Kanban Board, Lean Tool, literacy, packing, productivity
Procedia PDF Downloads 23510023 Monitoring the Rate of Expansion of Agricultural Fields in Mwekera Forest Reserve Using Remote Sensing and Geographic Information Systems
Authors: K. Kanja, M. Mweemba, K. Malungwa
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Due to the rampant population growth coupled with retrenchments currently going on in the Copper mines in Zambia, a number of people are resorting to land clearing for agriculture, illegal settlements as well as charcoal production among other vices. This study aims at assessing the rate of expansion of agricultural fields and illegal settlements in protected areas using remote sensing and Geographic Information System. Zambia’s Mwekera National Forest Reserve was used as a case study. Iterative Self-Organizing Data Analysis Technique (ISODATA), as well as maximum likelihood, supervised classification on four Landsat images as well as an accuracy assessment of the classifications was performed. Over the period under observation, results indicate annual percentage changes to be -0.03, -0.49 and 1.26 for agriculture, forests and settlement respectively indicating a higher conversion of forests into human settlements and agriculture.Keywords: geographic information system, land cover change, Landsat TM and ETM+, Mwekera forest reserve, remote sensing
Procedia PDF Downloads 14610022 Comparison of the Effects of Continuous Flow Microwave Pre-Treatment with Different Intensities on the Anaerobic Digestion of Sewage Sludge for Sustainable Energy Recovery from Sewage Treatment Plant
Authors: D. Hephzibah, P. Kumaran, N. M. Saifuddin
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Anaerobic digestion is a well-known technique for sustainable energy recovery from sewage sludge. However, sewage sludge digestion is restricted due to certain factors. Pre-treatment methods have been established in various publications as a promising technique to improve the digestibility of the sewage sludge and to enhance the biogas generated which can be used for energy recovery. In this study, continuous flow microwave (MW) pre-treatment with different intensities were compared by using 5 L semi-continuous digesters at a hydraulic retention time of 27 days. We focused on the effects of MW at different intensities on the sludge solubilization, sludge digestibility, and biogas production of the untreated and MW pre-treated sludge. The MW pre-treatment demonstrated an increase in the ratio of soluble chemical oxygen demand to total chemical oxygen demand (sCOD/tCOD) and volatile fatty acid (VFA) concentration. Besides that, the total volatile solid (TVS) removal efficiency and tCOD removal efficiency also increased during the digestion of the MW pre-treated sewage sludge compared to the untreated sewage sludge. Furthermore, the biogas yield also subsequently increases due to the pre-treatment effect. A higher MW power level and irradiation time generally enhanced the biogas generation which has potential for sustainable energy recovery from sewage treatment plant. However, the net energy balance tabulation shows that the MW pre-treatment leads to negative net energy production.Keywords: anaerobic digestion, biogas, microwave pre-treatment, sewage sludge
Procedia PDF Downloads 32310021 An Investigation on Material Removal Rate of EDM Process: A Response Surface Methodology Approach
Authors: Azhar Equbal, Anoop Kumar Sood, M. Asif Equbal, M. Israr Equbal
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In the present work response surface methodology (RSM) based central composite design (CCD) is used for analyzing the electrical discharge machining (EDM) process. For experimentation, mild steel is selected as work piece and copper is used as electrode. Three machining parameters namely current (I), spark on time (Ton) and spark off time (Toff) are selected as the input variables. The output or response chosen is material removal rate (MRR) which is to be maximized. To reduce the number of runs face centered central composite design (FCCCD) was used. ANOVA was used to determine the significance of parameter and interactions. The suitability of model is tested using Anderson darling (AD) plot. The results conclude that different parameters considered i.e. current, pulse on and pulse off time; all have dominant effect on the MRR. At last, the optimized parameter setting for maximizing MRR is found through main effect plot analysis.Keywords: EDM, electrode, MRR, RSM, ANOVA
Procedia PDF Downloads 30810020 Fresh State Properties of Steel Fiber Reinforced Self Compacting Concrete
Authors: Anil Nis, Nilufer Ozyurt Zihnioglu
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The object of the study is to investigate fresh state properties of the steel fiber reinforced self-compacting concrete (SFR-SCC). Three different steel fibers; straight (Vf:0.5%), hooked-end long (Vf:0.5% and 1%) and hybrid fibers (0.5%short+0.5%long) were used in the research aiming to obtain flow properties of non-fibrous self-compacting concrete. Fly ash was used as a supplementary with an optimum dosage of 30% of the total cementitious materials. Polycarboxylic ether based high-performance concrete superplasticizer was used to get high flowability with percentages ranging from 0.81% (non-fibrous SCC) to 1.07% (hybrid SF-SCC) of the cement weight. The flowability properties of SCCs were measured via slump flow and V-funnel tests; passing ability properties of SCCs were measured with J-Ring, L-Box, and U-Box tests. Workability results indicate that small increase on the superplasticizer dosages compensate the adverse effects of steel fibers on flowability properties of SSC. However, higher dosage fiber addition has a negative effect on passing ability properties, causing blocking of the mixes. In addition, compressive strength, tensile strength, and four point bending results were given. Results indicate that SCCs including steel fibers have superior performances on tensile and bending strength of concrete. Crack bridging capability of steel fibers prevents concrete from splitting, yields higher deformation and energy absorption capacities than non-fibrous SCCs.Keywords: fiber reinforced self-compacting concrete, fly ash, fresh state properties, steel fiber
Procedia PDF Downloads 22510019 Effect of Wavy Leading-Edges on Wings in Different Planetary Atmospheres
Authors: Vatasta Koul, Ayush Gupta, Vaibhav Sharma, Rajesh Yadav
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Today we are unmarking the secrets of the universe by exploring different stars and planets and most of the space exploration is done by unmanned space robots. In addition to our planet Earth, there are pieces of evidence that show other astronomical objects in our solar system such as Venus, Mars, Saturn’s moon Titan and Uranus support the flight of fixed wing air vehicles. In this paper, we take forward the concept of presence of large rounded tubercles along the leading edge of a wing and use it as a passive flow control device that will help in improving its aerodynamic performance and maneuverability. Furthermore, in this research, aerodynamic measurements and performance analysis of wavy leading tubercles on the fixed wings at 5-degree angle of attack are carried out after determination of the flow conditions on the selected planetary bodies. Wavelength and amplitude for the sinusoidal modifications on the leading edge are analyzed and simulations are carried out for three-dimensional NACA 0012 airfoil maintaining unity AR (Aspect Ratio). Tubercles have consistently demonstrated the ability to delay and decrease the severity of stall as per the studies were done in the Earth’s atmosphere. Implementing the same design on the leading edges of Micro-Air Vehicles (MAVs) and UAVs could make these aircrafts more stable over a greater range of angles of attack in different planetary environments of our solar system.Keywords: amplitude, NACA0012, tubercles, unmanned space robots
Procedia PDF Downloads 14910018 A Review of Information Systems Development in Developing Countries
Authors: B. N. Asare, O. A. Ajigini
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Information systems (IS) are highly important in the operation of private and public organisations in developing and developed countries. Developing countries are saddled with many project failures during the implementation of information systems. However, successful information systems are greatly needed in developing countries in order to enhance their economies. This paper is highly important in view of the high failure rate of information systems in developing countries which needs to be reduced to minimum acceptable levels by means of recommended interventions. This paper centres on a review of IS development in developing countries. The paper presents evidences of the IS successes and failures in developing countries and posits a model to address the IS failures. The proposed model can then be utilised by developing countries to reduce their IS project implementation failure rate. A comparison is drawn between IS development in developing countries and developed countries. The paper provides valuable information to assist in reducing IS failure, and developing IS models and theories on IS development for developing countries.Keywords: developing countries, information systems, IS development, information systems failure, information systems success, information systems success model
Procedia PDF Downloads 38310017 The Applications of Four Fingers Theory: The Proof of 66 Acupoints under the Human Elbow and Knee
Authors: Chih-I. Tsai, Yu-Chien. Lin
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Through experiences of clinical practices, it is discovered that locations on the body at a level of four fingerbreadth above and below the joints are the points at which muscles connect to tendons, and since the muscles and tendons possess opposite characteristics, muscles are full of blood but lack qi, while tendons are full of qi but lack blood, these points on our body become easily blocked. It is proposed that through doing acupuncture or creating localized pressure to the areas four fingerbreadths above and below our joints, with an elastic bandage, we could help the energy, also known as qi, to flow smoothly in our body and further improve our health. Based on the Four Fingers Theory, we understand that human height is 22 four fingerbreadths. In addition, qi and blood travel through 24 meridians, 50 times each day, and they flow through 6 cun with every human breath. We can also understand the average number of human heartbeats is 75 times per minute. And the function of qi-blood circulation system in Traditional Chinese Medicine is the same as the blood circulation in Western Medical Science. Informed by Four Fingers Theory, this study further examined its applications in acupuncture practices. The research question is how Four Fingers Theory proves what has been mentioned in Nei Jing that there are 66 acupoints under a human’s elbow and knee. In responding to the research question, there are 66 acupoints under a human’s elbow and knee. Four Fingers Theory facilitated the creation of the acupuncture naming and teaching system. It is expected to serve as an approachable and effective way to deliver knowledge of acupuncture to the public worldwide.Keywords: four fingers theory, meridians circulation, 66 acupoints under human elbow and knee, acupuncture
Procedia PDF Downloads 30210016 Demarcating Wetting States in Pressure-Driven Flows by Poiseuille Number
Authors: Anvesh Gaddam, Amit Agrawal, Suhas Joshi, Mark Thompson
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An increase in surface area to volume ratio with a decrease in characteristic length scale, leads to a rapid increase in pressure drop across the microchannel. Texturing the microchannel surfaces reduce the effective surface area, thereby decreasing the pressured drop. Surface texturing introduces two wetting states: a metastable Cassie-Baxter state and stable Wenzel state. Predicting wetting transition in textured microchannels is essential for identifying optimal parameters leading to maximum drag reduction. Optical methods allow visualization only in confined areas, therefore, obtaining whole-field information on wetting transition is challenging. In this work, we propose a non-invasive method to capture wetting transitions in textured microchannels under flow conditions. To this end, we tracked the behavior of the Poiseuille number Po = f.Re, (with f the friction factor and Re the Reynolds number), for a range of flow rates (5 < Re < 50), and different wetting states were qualitatively demarcated by observing the inflection points in the f.Re curve. Microchannels with both longitudinal and transverse ribs with a fixed gas fraction (δ, a ratio of shear-free area to total area) and at a different confinement ratios (ε, a ratio of rib height to channel height) were fabricated. The measured pressure drop values for all the flow rates across the textured microchannels were converted into Poiseuille number. Transient behavior of the pressure drop across the textured microchannels revealed the collapse of liquid-gas interface into the gas cavities. Three wetting states were observed at ε = 0.65 for both longitudinal and transverse ribs, whereas, an early transition occurred at Re ~ 35 for longitudinal ribs at ε = 0.5, due to spontaneous flooding of the gas cavities as the liquid-gas interface ruptured at the inlet. In addition, the pressure drop in the Wenzel state was found to be less than the Cassie-Baxter state. Three-dimensional numerical simulations confirmed the initiation of the completely wetted Wenzel state in the textured microchannels. Furthermore, laser confocal microscopy was employed to identify the location of the liquid-gas interface in the Cassie-Baxter state. In conclusion, the present method can overcome the limitations posed by existing techniques, to conveniently capture wetting transition in textured microchannels.Keywords: drag reduction, Poiseuille number, textured surfaces, wetting transition
Procedia PDF Downloads 16510015 Investigation for Pixel-Based Accelerated Aging of Large Area Picosecond Photo-Detectors
Authors: I. Tzoka, V. A. Chirayath, A. Brandt, J. Asaadi, Melvin J. Aviles, Stephen Clarke, Stefan Cwik, Michael R. Foley, Cole J. Hamel, Alexey Lyashenko, Michael J. Minot, Mark A. Popecki, Michael E. Stochaj, S. Shin
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Micro-channel plate photo-multiplier tubes (MCP-PMTs) have become ubiquitous and are widely considered potential candidates for next generation High Energy Physics experiments due to their picosecond timing resolution, ability to operate in strong magnetic fields, and low noise rates. A key factor that determines the applicability of MCP-PMTs in their lifetime, especially when they are used in high event rate experiments. We have developed a novel method for the investigation of the aging behavior of an MCP-PMT on an accelerated basis. The method involves exposing a localized region of the MCP-PMT to photons at a high repetition rate. This pixel-based method was inspired by earlier results showing that damage to the photocathode of the MCP-PMT occurs primarily at the site of light exposure and that the surrounding region undergoes minimal damage. One advantage of the pixel-based method is that it allows the dynamics of photo-cathode damage to be studied at multiple locations within the same MCP-PMT under different operating conditions. In this work, we use the pixel-based accelerated lifetime test to investigate the aging behavior of a 20 cm x 20 cm Large Area Picosecond Photo Detector (LAPPD) manufactured by INCOM Inc. at multiple locations within the same device under different operating conditions. We compare the aging behavior of the MCP-PMT obtained from the first lifetime test conducted under high gain conditions to the lifetime obtained at a different gain. Through this work, we aim to correlate the lifetime of the MCP-PMT and the rate of ion feedback, which is a function of the gain of each MCP, and which can also vary from point to point across a large area (400 $cm^2$) MCP. The tests were made possible by the uniqueness of the LAPPD design, which allows independent control of the gain of the chevron stacked MCPs. We will further discuss the implications of our results for optimizing the operating conditions of the detector when used in high event rate experiments.Keywords: electron multipliers (vacuum), LAPPD, lifetime, micro-channel plate photo-multipliers tubes, photoemission, time-of-flight
Procedia PDF Downloads 18310014 Computational Fluid Dynamics Based Analysis of Heat Exchanging Performance of Rotary Thermal Wheels
Authors: H. M. D. Prabhashana Herath, M. D. Anuradha Wickramasinghe, A. M. C. Kalpani Polgolla, R. A. C. Prasad Ranasinghe, M. Anusha Wijewardane
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The demand for thermal comfort in buildings in hot and humid climates increases progressively. In general, buildings in hot and humid climates spend more than 60% of the total energy cost for the functionality of the air conditioning (AC) system. Hence, it is required to install energy efficient AC systems or integrate energy recovery systems for both new and/or existing AC systems whenever possible, to reduce the energy consumption by the AC system. Integrate a Rotary Thermal Wheel as the energy recovery device of an existing AC system has shown very promising with attractive payback periods of less than 5 years. A rotary thermal wheel can be located in the Air Handling Unit (AHU) of a central AC system to recover the energy available in the return air stream. During this study, a sensitivity analysis was performed using a CFD (Computational Fluid Dynamics) software to determine the optimum design parameters (i.e., rotary speed and parameters of the matrix profile) of a rotary thermal wheel for hot and humid climates. The simulations were performed for a sinusoidal matrix geometry. Variation of sinusoidal matrix parameters, i.e., span length and height, were also analyzed to understand the heat exchanging performance and the induced pressure drop due to the air flow. The results show that the heat exchanging performance increases when increasing the wheel rpm. However, the performance increment rate decreases when increasing the rpm. As a result, it is more advisable to operate the wheel at 10-20 rpm. For the geometry, it was found that the sinusoidal geometries with lesser spans and higher heights have higher heat exchanging capabilities. Considering the sinusoidal profiles analyzed during the study, the geometry with 4mm height and 3mm width shows better performance than the other combinations.Keywords: air conditioning, computational fluid dynamics, CFD, energy recovery, heat exchangers
Procedia PDF Downloads 13210013 Effect of Diet Inulin Prebiotic on Growth, Reproductive Performance, Carcass Composition and Resistance to Environmental Stresses in Zebra Danio (Danio rerio)
Authors: Ehsan Ahmadifar
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In this research, the effects of different levels (control group (T0), (T1)1, (T2)2 and (T3)3 gr Inulin per Kg diet) of prebiotic Inulin as nutritional supplement on Danio rerio were investigated for 4 month. Since the beginning of feeding larvae until adult (average weight: 67.1 g, length: 4.5 cm) were fed with experimental diets. The survival rate of fish had no significant effect on rate survival (P > 0.05). The highest food conversion ratio (FCR) was in control group and the lowest was observed in T3. Treatment of T3 significantly caused the best feed conversion ratio in Zebra fish (P < 0.05). By increasing the inulin diet during the experiment, specific growth rate increased. The highest and the lowest body weight gain and condition factor were observed in T3 and control, respectively (P < 0.05). Adding 3 gr inulin in Zebra fish diet can improve the performance of the growth indices and final biomass, also this prebiotic can be considered as a suitable supplement for Cyprinidae diet. In the first sampling stage for feeding fish, fat and muscle protein was significantly higher than the second sampling stage (P < 0.05). Given that the second stage fish were full sexual maturity, the amount of fat in muscle decreased (P < 0.05). Moisture and ash levels were significantly (P < 0.05) higher in the second stage sampling than the first stage. Overall, different stage of living affected on muscle chemical composition muscle. Reproductive performance in treatment T2 and T3 were significantly higher than other treatments (P < 0.05). According to the results, the prebiotic inulin does not have a significant impact on the sex ratio in zebrafish (P > 0.05). Based on histology of the gonads, the use of dietary inulin accelerates the process of gonad development in zebrafish.Keywords: inulin, zebrafish, reproduction, histology
Procedia PDF Downloads 31010012 Development and Implementation of a Business Technology Program Based on Techniques for Reusing Water in a Colombian Company
Authors: Miguel A. Jimenez Barros, Elyn L. Solano Charris, Luis E. Ramirez, Lauren Castro Bolano, Carlos Torres Barreto, Juliana Morales Cubillo
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This project sought to mitigate the high levels of water consumption in industrial processes in accordance with the water-rationing plan promoted at national and international level due to the water consumption projections published by the United Nations. Water consumption has three main uses, municipal (common use), agricultural and industrial where the latter consumes a minimum percentage (around 20% of the total consumption). Awareness on world water scarcity, a Colombian company responsible for generation of massive consumption products, decided to implement politics and techniques for water treatment, recycling, and reuse. The project consisted in a business technology program that permits a better use of wastewater caused by production operations. This approach reduces the potable water consumption, generates better conditions of water in the sewage dumps, generates a positive environmental impact for the region, and is a reference model in national and international levels. In order to achieve the objective, a process flow diagram was used in order to define the industrial processes that required potable water. This strategy allowed the industry to determine a water reuse plan at the operational level without affecting the requirements associated with the manufacturing process and even more, to support the activities developed in administrative buildings. Afterwards, the company made an evaluation and selection of the chemical and biological processes required for water reuse, in compliance with the Colombian Law. The implementation of the business technology program optimized the water use and recirculation rate up to 70%, accomplishing an important reduction of the regional environmental impact.Keywords: bio-reactor, potable water, reverse osmosis, water treatment
Procedia PDF Downloads 23910011 Synthesis of (S)-Naproxen Based Amide Bond Forming Chiral Reagent and Application for Liquid Chromatographic Resolution of (RS)-Salbutamol
Authors: Poonam Malik, Ravi Bhushan
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This work describes a very efficient approach for synthesis of activated ester of (S)-naproxen which was characterized by UV, IR, ¹HNMR, elemental analysis and polarimetric studies. It was used as a C-N bond forming chiral derivatizing reagent for further synthesis of diastereomeric amides of (RS)-salbutamol (a β₂ agonist that belongs to the group β-adrenolytic and is marketed as racamate) under microwave irradiation. The diastereomeric pair was separated by achiral phase HPLC, using mobile phase in gradient mode containing methanol and aqueous triethylaminephosphate (TEAP); separation conditions were optimized with respect to pH, flow rate, and buffer concentration and the method of separation was validated as per International Council for Harmonisation (ICH) guidelines. The reagent proved to be very effective for on-line sensitive detection of the diastereomers with very low limit of detection (LOD) values of 0.69 and 0.57 ng mL⁻¹ for diastereomeric derivatives of (S)- and (R)-salbutamol, respectively. The retention times were greatly reduced (2.7 min) with less consumption of organic solvents and large (α) as compared to literature reports. Besides, the diastereomeric derivatives were separated and isolated by preparative HPLC; these were characterized and were used as standard reference samples for recording ¹HNMR and IR spectra for determining absolute configuration and elution order; it ensured the success of diastereomeric synthesis and established the reliability of enantioseparation and eliminated the requirement of pure enantiomer of the analyte which is generally not available. The newly developed reagent can suitably be applied to several other amino group containing compounds either from organic syntheses or pharmaceutical industries because the presence of (S)-Npx as a strong chromophore would allow sensitive detection.This work is significant not only in the area of enantioseparation and determination of absolute configuration of diastereomeric derivatives but also in the area of developing new chiral derivatizing reagents (CDRs).Keywords: chiral derivatizing reagent, naproxen, salbutamol, synthesis
Procedia PDF Downloads 15610010 Harmonic Pollution Caused by Non-Linear Load: Analysis and Identification
Authors: K. Khlifi, A. Haddouk, M. Hlaili, H. Mechergui
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The present paper provides a detailed analysis of prior methods and approaches for non-linear load identification in residential buildings. The main goal of this analysis is to decipher the distorted signals and to estimate the harmonics influence on power systems. We have performed an analytical study of non-linear loads behavior in the residential environment. Simulations have been performed in order to evaluate the distorted rate of the current and follow his behavior. To complete this work, an instrumental platform has been realized to carry out practical tests on single-phase non-linear loads which illustrate the current consumption of some domestic appliances supplied with single-phase sinusoidal voltage. These non-linear loads have been processed and tracked in order to limit their influence on the power grid and to reduce the Joule effect losses. As a result, the study has allowed to identify responsible circuits of harmonic pollution.Keywords: distortion rate, harmonic analysis, harmonic pollution, non-linear load, power factor
Procedia PDF Downloads 14810009 Research on the Cognition and Actual Phenomenon of School Bullying from the Perspective of Students
Authors: Chia-Chun Wu, Yu-Hsien Sung
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This study aims to examine the consistency between students’ predictions and their actual observations on the bullying prevalence rate among different types of high-risk victims, thereby clarifying the reliability of students’ reports on the identification of bullying. A total of 1,732 Taiwanese students (734 males and 998 females) participated in this study. A Rasch model was adopted for data analysis. The results showed that students with “personality or behavioral issues” are more likely to be bullied in schools, based on both students’ predictions and actual observations. Moreover, the results differed significantly between genders and between various educational levels in students’ predictions and their actual observations on the bullying prevalence rate of different types of high-risk victims. To summarize, this study not only suggests that students’ reports on the identification of bullying are accurate and could be a valuable reference in terms of recognizing a bullying incident, but it also argues that more attention should be paid to students’ gender and educational level when taking their perspectives into consideration when it comes to identifying bullying behaviors.Keywords: school bullying, student, bullying recognition, high-risk victims
Procedia PDF Downloads 8810008 Effects of Matrix Properties on Surfactant Enhanced Oil Recovery in Fractured Reservoirs
Authors: Xiaoqian Cheng, Jon Kleppe, Ole Torsæter
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The properties of rocks have effects on efficiency of surfactant. One objective of this study is to analyze the effects of rock properties (permeability, porosity, initial water saturation) on surfactant spontaneous imbibition at laboratory scale. The other objective is to evaluate existing upscaling methods and establish a modified upscaling method. A core is put in a container that is full of surfactant solution. Assume there is no space between the bottom of the core and the container. The core is modelled as a cuboid matrix with a length of 3.5 cm, a width of 3.5 cm, and a height of 5 cm. The initial matrix, brine and oil properties are set as the properties of Ekofisk Field. The simulation results of matrix permeability show that the oil recovery rate has a strong positive linear relationship with matrix permeability. Higher oil recovery is obtained from the matrix with higher permeability. One existing upscaling method is verified by this model. The study on matrix porosity shows that the relationship between oil recovery rate and matrix porosity is a negative power function. However, the relationship between ultimate oil recovery and matrix porosity is a positive power function. The initial water saturation of matrix has negative linear relationships with ultimate oil recovery and enhanced oil recovery. However, the relationship between oil recovery and initial water saturation is more complicated with the imbibition time because of the transition of dominating force from capillary force to gravity force. Modified upscaling methods are established. The work here could be used as a reference for the surfactant application in fractured reservoirs. And the description of the relationships between properties of matrix and the oil recovery rate and ultimate oil recovery helps to improve upscaling methods.Keywords: initial water saturation, permeability, porosity, surfactant EOR
Procedia PDF Downloads 16410007 Investigation of Fusion Reactions in ¹⁶O + ¹⁵⁶Gd System
Authors: Rahbar Ali, Nitin Sharma, Dharmendra Singh, R. P. Singh, S. Muralithar, M. Afzal Ansari
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Heavy-ion-induced reactions on intermediate-mass targets are inherently complex, particularly at low energy levels. The study of these nuclear reactions, especially complete and incomplete fusion reactions, is of utmost importance to nuclear physicists. Researchers have demonstrated interest in exploring the mechanisms of nuclear reactions using heavy-ion beams at energies below 10 MeV/nucleon. In this study, the reaction mechanism of ¹⁶O⁷+ projectiles incident on a ¹⁵⁶Gd target at beam energies ranging from 4 to 7 MeV/nucleon was investigated. To gain a comprehensive understanding of the underlying processes, the excitation functions of evaporation residues produced via complete fusion (CF) and/or incomplete fusion (ICF) were measured. The evaporation residues were populated through xn/pxn and αxn/αpxn emission channels. The measured cross-sections of these residues were compared with the predictions of the statistical model codes PACE-4 and EMPIRE. The measured excitation functions of reaction residues populated through xn and pxn channels are in good agreement with the predictions of the statistical model code PACE4 and EMPIRE. This confirms that the production of these residues is solely due to the CF process. However, a significant enhancement was observed in the measured cross-sections of residues populated through α-emitting channels compared to theoretical predictions. This enhancement in the cross sections for α-emitting channels is ascribed to the ICF processes. The fusion cross-section data were also analyzed within the universal fusion function (UFF) and universal reaction function (URF) approach. The observed fusion suppression is primarily attributed to the breakup of the projectile. The ICF contribution in the reaction is dependent on projectile energy, mass asymmetry of the system and deformation of the target.Keywords: nuclear reactions, above barrier reactions, evaporation residues, universal fusion function
Procedia PDF Downloads 1310006 Liquid Tin(II) Alkoxide Initiators for Use in the Ring-Opening Polymerisation of Cyclic Ester Monomers
Authors: Sujitra Ruengdechawiwat, Robert Molloy, Jintana Siripitayananon, Runglawan Somsunan, Paul D. Topham, Brian J. Tighe
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The main aim of this research has been to design and synthesize some completely soluble liquid tin(II) alkoxide initiators for use in the ring-opening polymerisation (ROP) of cyclic ester monomers. This is in contrast to conventional tin(II) alkoxides in solid form which tend to be molecular aggregates and difficult to dissolve. The liquid initiators prepared were bis(tin(II) monooctoate) diethylene glycol ([Sn(Oct)]2DEG) and bis(tin(II) monooctoate) ethylene glycol ([Sn(Oct)]2EG). Their efficiencies as initiators in the bulk ROP of ε-caprolactone (CL) at 130oC were studied kinetically by dilatometry. Kinetic data over the 20-70% conversion range was used to construct both first-order and zero-order rate plots. It was found that the rate data fitted more closely to first-order kinetics with respect to the monomer concentration and gave higher first-order rate constants than the corresponding tin(II) octoate/diol initiating systems normally used to generate the tin(II) alkoxide in situ. Since the ultimate objective of this work is to produce copolymers suitable for biomedical use as absorbable monofilament surgical sutures, poly(L-lactide-co-ε-caprolactone) 75:25 mol %, P(LL-co-CL), copolymers were synthesized using both solid and liquid tin(II) alkoxide initiators at 130°C for 48 hrs. The statistical copolymers were obtained in near-quantitative yields with compositions (from 1H-NMR) close to the initial comonomer feed ratios. The monomer sequencing (from 13C-NMR) was partly random and partly blocky (gradient-type) due to the much differing monomer reactivity ratios (rLL >> rCL). From GPC, the copolymers obtained using the soluble liquid tin(II) alkoxides were found to have higher molecular weights (Mn = 40,000-100,000) than those from the only partially soluble solid initiators (Mn = 30,000-52,000).Keywords: biodegradable polyesters, poly(L-lactide-co-ε-caprolactone), ring-opening polymerisation, tin(II) alkoxide
Procedia PDF Downloads 19410005 River Analysis System Model for Proposed Weirs at Downstream of Large Dam, Thailand
Authors: S. Chuenchooklin
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This research was conducted in the Lower Ping River Basin downstream of the Bhumibol Dam and the Lower Wang River Basin in Tak Province, Thailand. Most of the tributary streams of the Ping can be considered as ungauged catchments. There are 10- pumping station installation at both river banks of the Ping in Tak Province. Recently, most of them could not fully operate due to the water amount in the river below the level that would be pumping, even though included water from the natural river and released flow from the Bhumibol Dam. The aim of this research was to increase the performance of those pumping stations using weir projects in the Ping. Therefore, the river analysis system model (HEC-RAS) was applied to study the hydraulic behavior of water surface profiles in the Ping River with both cases of existing conditions and proposed weirs during the violent flood in 2011 and severe drought in 2013. Moreover, the hydrologic modeling system (HMS) was applied to simulate lateral streamflow hydrograph from ungauged catchments of the Ping. The results of HEC-RAS model calibration with existing conditions in 2011 showed best trial roughness coefficient for the main channel of 0.026. The simulated water surface levels fitted to observation data with R2 of 0.8175. The model was applied to 3 proposed cascade weirs with 2.35 m in height and found surcharge water level only 0.27 m higher than the existing condition in 2011. Moreover, those weirs could maintain river water levels and increase of those pumping performances during less river flow in 2013.Keywords: HEC-RAS, HMS, pumping stations, cascade weirs
Procedia PDF Downloads 39810004 The Role of Nano Glass Flakes on Morphology, Dynamic-Mechanical Properties and Crystallization Behavior of Poly (Ethylene Terephthalate)
Authors: Fatemeh Alsadat Miri, Morteza Ehsani, Hossein Ali Khonakdar, Behjat Kavyani
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This paper studies the effect of nano glass flakes on morphology, dynamic-mechanical properties, and crystallization behavior of poly (ethylene terephthalate) (PET). The concentration of nano glass flakes was varied from 0.5, 1, 2, and 3% wt of the total formulation. Scanning electron microscopy (SEM) micrographs showed the poor distribution of nano-glass flake particles in PET, as well as low adhesion of particles to the polymer matrix. According to differential scanning calorimetry (DSC), the crystallization rate and crystallization temperature of PET were increased by the addition of nano glass flakes. The crystallization rate of PET was increased from 31.41% to 34.25% by the incorporation of 1%wt of nano glass flakes. Based on the results of the dynamic-mechanical analysis, the storage modulus of PET gets increased by adding nano glass flakes, especially below glass transition temperature (Tg). The glass transition of PET did not change remarkably with the addition of nano glass flakes. Moreover, the use of nano glass flakes reduced the impact strength of PET.Keywords: PET, nano glass flakes, morphology, crystallization
Procedia PDF Downloads 13210003 Deorbiting Performance of Electrodynamic Tethers to Mitigate Space Debris
Authors: Giulia Sarego, Lorenzo Olivieri, Andrea Valmorbida, Carlo Bettanini, Giacomo Colombatti, Marco Pertile, Enrico C. Lorenzini
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International guidelines recommend removing any artificial body in Low Earth Orbit (LEO) within 25 years from mission completion. Among disposal strategies, electrodynamic tethers appear to be a promising option for LEO, thanks to the limited storage mass and the minimum interface requirements to the host spacecraft. In particular, recent technological advances make it feasible to deorbit large objects with tether lengths of a few kilometers or less. To further investigate such an innovative passive system, the European Union is currently funding the project E.T.PACK – Electrodynamic Tether Technology for Passive Consumable-less Deorbit Kit in the framework of the H2020 Future Emerging Technologies (FET) Open program. The project focuses on the design of an end of life disposal kit for LEO satellites. This kit aims to deploy a taped tether that can be activated at the spacecraft end of life to perform autonomous deorbit within the international guidelines. In this paper, the orbital performance of the E.T.PACK deorbiting kit is compared to other disposal methods. Besides, the orbital decay prediction is parametrized as a function of spacecraft mass and tether system performance. Different values of length, width, and thickness of the tether will be evaluated for various scenarios (i.e., different initial orbital parameters). The results will be compared to other end-of-life disposal methods with similar allocated resources. The analysis of the more innovative system’s performance with the tape coated with a thermionic material, which has a low work-function (LWT), for which no active component for the cathode is required, will also be briefly discussed. The results show that the electrodynamic tether option can be a competitive and performant solution for satellite disposal compared to other deorbit technologies.Keywords: deorbiting performance, H2020, spacecraft disposal, space electrodynamic tethers
Procedia PDF Downloads 18210002 The Suitability of Agile Practices in Healthcare Industry with Regard to Healthcare Regulations
Authors: Mahmood Alsaadi, Alexei Lisitsa
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Nowadays, medical devices rely completely on software whether as whole software or as embedded software, therefore, the organization that develops medical device software can benefit from adopting agile practices. Using agile practices in healthcare software development industries would bring benefits such as producing a product of a high-quality with low cost and in short period. However, medical device software development companies faced challenges in adopting agile practices. These due to the gaps that exist between agile practices and the requirements of healthcare regulations such as documentation, traceability, and formality. This research paper will conduct a study to investigate the adoption rate of agile practice in medical device software development, and they will extract and outline the requirements of healthcare regulations such as Food and Drug Administration (FDA), Health Insurance Portability and Accountability Act (HIPAA), and Medical Device Directive (MDD) that affect directly or indirectly on software development life cycle. Moreover, this research paper will evaluate the suitability of using agile practices in healthcare industries by analyzing the most popular agile practices such as eXtream Programming (XP), Scrum, and Feature-Driven Development (FDD) from healthcare industry point of view and in comparison with the requirements of healthcare regulations. Finally, the authors propose an agile mixture model that consists of different practices from different agile methods. As result, the adoption rate of agile practices in healthcare industries still low and agile practices should enhance with regard to requirements of the healthcare regulations in order to be used in healthcare software development organizations. Therefore, the proposed agile mixture model may assist in minimizing the gaps existing between healthcare regulations and agile practices and increase the adoption rate in the healthcare industry. As this research paper part of the ongoing project, an evaluation of agile mixture model will be conducted in the near future.Keywords: adoption of agile, agile gaps, agile mixture model, agile practices, healthcare regulations
Procedia PDF Downloads 23910001 Knowledge Transformation Flow (KTF) of Visually Impaired Students: The Virtual Knowledge System as a New Service Innovation
Authors: Chatcai Tangsri, Onjaree Na-Takuatoong
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This paper aims to present the key factors that support the decision to use the technology and to present the knowledge transformation flow of visually impaired students after the use of virtual knowledge system as proposed as a new service innovation to universities in Thailand. Correspondents of 27 visually impaired students are involved in this research. Total of 25 students are selected from the University that mainly conducts non-classroom teaching environment; while another 2 visually impaired students are selected from classroom teaching environment. All of them are fully involved in the study along 8 weeks duration. All correspondents are classified into 5 small groups in various conditions. The research results revealed that the involvement from knowledge facilitator can push out for the behavioral actual use of the virtual knowledge system although there is no any developed intention to use behaviors. Secondly, the situations that the visually impaired students inadequate of the knowledge sources that usually provided by assistants i.e. peers, audio files etc. In this case, they will use the virtual knowledge system for both knowledge access and knowledge transfer request. With this evidence, the need of knowledge would play a stronger role than all technology acceptance factors. Finally, this paper revealed that the knowledge transfer in the normal method that students have a chance to physically meet up is still confirmed as their preference method. In term of other aspects of technology acceptance, it will be discussed together with challenges and recommendations at the end of this paper.Keywords: knowledge system, visually impaired students, higher education, knowledge management enable technology, synchronous/asynchronous knowledge access, synchronous/asynchronous knowledge transfer
Procedia PDF Downloads 35910000 Computational Fluid Dynamics Simulation of a Boiler Outlet Header Constructed of Inconel Alloy 740H
Authors: Sherman Ho, Ahmed Cherif Megri
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Headers play a critical role in conveying steam to regulate heating system temperatures. While various materials like steel grades 91 and 92 have been traditionally used for pipes, this research proposes the use of a robust and innovative material, INCONEL Alloy 740H. Boilers in power plant configurations are exposed to cycling conditions due to factors such as daily, seasonal, and yearly variations in weather. These cycling conditions can lead to the deterioration of headers, which are vital components with intricate geometries. Header failures result in substantial financial losses from repair costs and power plant shutdowns, along with significant public inconveniences such as the loss of heating and hot water. To address this issue and seek solutions, a mechanical analysis, as well as a structural analysis, are recommended. Transient analysis to predict heat transfer conditions is of paramount importance, as the direction of heat transfer within the header walls and the passing steam can vary based on the location of interest, load, and operating conditions. The geometry and material of the header are also crucial design factors, and the choice of pipe material depends on its usage. In this context, the heat transfer coefficient plays a vital role in header design and analysis. This research employs ANSYS Fluent, a numerical simulation program, to understand header behavior, predict heat transfer, and analyze mechanical phenomena within the header. Transient simulations are conducted to investigate parameters like heat transfer coefficient, pressure loss coefficients, and heat flux, with the results used to optimize header design.Keywords: CFD, header, power plant, heat transfer coefficient, simulation using experimental data
Procedia PDF Downloads 699999 Study of Cahn-Hilliard Equation to Simulate Phase Separation
Authors: Nara Guimarães, Marcelo Aquino Martorano, Douglas Gouvêa
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An investigation into Cahn-Hilliard equation was carried out through numerical simulation to identify a possible phase separation for one and two dimensional domains. It was observed that this equation can reproduce important mass fluxes necessary for phase separation within the miscibility gap and for coalescence of particles.Keywords: Cahn-Hilliard equation, miscibility gap, phase separation, dimensional domains
Procedia PDF Downloads 5199998 Extraction of Scandium (Sc) from an Ore with Functionalized Nanoporous Silicon Adsorbent
Authors: Arezoo Rahmani, Rinez Thapa, Juha-Matti Aalto, Petri Turhanen, Jouko Vepsalainen, Vesa-PekkaLehto, Joakim Riikonen
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Production of Scandium (Sc) is a complicated process because Sc is found only in low concentrations in ores and the concentration of Sc is very low compared with other metals. Therefore, utilization of typical extraction processes such as solvent extraction is problematic in scandium extraction. The Adsorption/desorption method can be used, but it is challenging to prepare materials, which have good selectivity, high adsorption capacity, and high stability. Therefore, efficient and environmentally friendly methods for Sc extraction are needed. In this study, the nanoporous composite material was developed for extracting Sc from an Sc ore. The nanoporous composite material offers several advantageous properties such as large surface area, high chemical and mechanical stability, fast diffusion of the metals in the material and possibility to construct a filter out of the material with good flow-through properties. The nanoporous silicon material was produced by first stabilizing the surfaces with a silicon carbide layer and then functionalizing the surface with bisphosphonates that act as metal chelators. The surface area and porosity of the material were characterized by N₂ adsorption and the morphology was studied by scanning electron microscopy (SEM). The bisphosphonate content of the material was studied by thermogravimetric analysis (TGA). The concentration of metal ions in the adsorption/desorption experiments was measured with inductively coupled plasma mass spectrometry (ICP-MS). The maximum capacity of the material was 25 µmol/g Sc at pH=1 and 45 µmol/g Sc at pH=3, obtained from adsorption isotherm. The selectivity of the material towards Sc in artificial solutions containing several metal ions was studied at pH one and pH 3. The result shows good selectivity of the nanoporous composite towards adsorption of Sc. Scandium was less efficiently adsorbed from solution leached from the ore of Sc because of excessive amounts of iron (Fe), aluminum (Al) and titanium (Ti) which disturbed the adsorption process. For example, the concentration of Fe was more than 4500 ppm, while the concentration of Sc was only three ppm, approximately 1500 times lower. Precipitation methods were developed to lower the concentration of the metals other than Sc. Optimal pH for precipitation was found to be pH 4. The concentration of Fe, Al and Ti were decreased by 99, 70, 99.6%, respectively, while the concentration of Sc decreased only 22%. Despite the large reduction in the concentration of other metals, more work is needed to further increase the relative concentration of Sc compared with other metals to efficiently extract it using the developed nanoporous composite material. Nevertheless, the developed material may provide an affordable, efficient and environmentally friendly method to extract Sc on a large scale.Keywords: adsorption, nanoporous silicon, ore solution, scandium
Procedia PDF Downloads 1519997 Experimental Set-up for the Thermo-Hydric Study of a Wood Chips Bed Crossed by an Air Flow
Authors: Dimitri Bigot, Bruno Malet-Damour, Jérôme Vigneron
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Many studies have been made about using bio-based materials in buildings. The goal is to reduce its environmental footprint by analyzing its life cycle. This can lead to minimize the carbon emissions or energy consumption. A previous work proposed to numerically study the feasibility of using wood chips to regulate relative humidity inside a building. This has shown the capability of a wood chips bed to regulate humidity inside the building, to improve thermal comfort, and so potentially reduce building energy consumption. However, it also shown that some physical parameters of the wood chips must be identified to validate the proposed model and the associated results. This paper presents an experimental setup able to study such a wood chips bed with different solicitations. It consists of a simple duct filled with wood chips and crossed by an air flow with variable temperature and relative humidity. Its main objective is to study the thermal behavior of the wood chips bed by controlling temperature and relative humidity of the air that enters into it and by observing the same parameters at the output. First, the experimental set up is described according to previous results. A focus is made on the particular properties that have to be characterized. Then some case studies are presented in relation to the previous results in order to identify the key physical properties. Finally, the feasibility of the proposed technology is discussed, and some model validation paths are given.Keywords: wood chips bed, experimental set-up, bio-based material, desiccant, relative humidity, water content, thermal behaviour, air treatment
Procedia PDF Downloads 1289996 Shear Stress and Effective Structural Stress Fields of an Atherosclerotic Coronary Artery
Authors: Alireza Gholipour, Mergen H. Ghayesh, Anthony Zander, Stephen J. Nicholls, Peter J. Psaltis
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A three-dimensional numerical model of an atherosclerotic coronary artery is developed for the determination of high-risk situation and hence heart attack prediction. Employing the finite element method (FEM) using ANSYS, fluid-structure interaction (FSI) model of the artery is constructed to determine the shear stress distribution as well as the von Mises stress field. A flexible model for an atherosclerotic coronary artery conveying pulsatile blood is developed incorporating three-dimensionality, artery’s tapered shape via a linear function for artery wall distribution, motion of the artery, blood viscosity via the non-Newtonian flow theory, blood pulsation via use of one-period heartbeat, hyperelasticity via the Mooney-Rivlin model, viscoelasticity via the Prony series shear relaxation scheme, and micro-calcification inside the plaque. The material properties used to relate the stress field to the strain field have been extracted from clinical data from previous in-vitro studies. The determined stress fields has potential to be used as a predictive tool for plaque rupture and dissection. The results show that stress concentration due to micro-calcification increases the von Mises stress significantly; chance of developing a crack inside the plaque increases. Moreover, the blood pulsation varies the stress distribution substantially for some cases.Keywords: atherosclerosis, fluid-structure interaction, coronary arteries, pulsatile flow
Procedia PDF Downloads 1769995 Comparison of Loosely Coupled and Tightly Coupled INS/GNSS Architecture for Guided Rocket Navigation System
Authors: Rahmat Purwoko, Bambang Riyanto Trilaksono
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This paper gives comparison of INS/GNSS architecture namely Loosely Coupled and Tightly Coupled using Hardware in the Loop Simulation in Guided Missile RKX-200 rocket model. INS/GNSS Tightly Coupled architecture requires pseudo-range, pseudo-range rate, and position and velocity of each satellite in constellation from GPS (Global Positioning System) measurement. The Loosely Coupled architecture use estimated position and velocity from GNSS receiver. INS/GNSS architecture also requires angular rate and specific force measurement from IMU (Inertial Measurement Unit). Loosely Coupled arhitecture designed using 15 states Kalman Filter and Tightly Coupled designed using 17 states Kalman Filter. Integration algorithm calculation using ECEF frame. Navigation System implemented Zedboard All Programmable SoC.Keywords: kalman filter, loosely coupled, navigation system, tightly coupled
Procedia PDF Downloads 313