Search results for: safety transfer
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5902

Search results for: safety transfer

5842 An Improved Heat Transfer Prediction Model for Film Condensation inside a Tube with Interphacial Shear Effect

Authors: V. G. Rifert, V. V. Gorin, V. V. Sereda, V. V. Treputnev

Abstract:

The analysis of heat transfer design methods in condensing inside plain tubes under existing influence of shear stress is presented in this paper. The existing discrepancy in more than 30-50% between rating heat transfer coefficients and experimental data has been noted. The analysis of existing theoretical and semi-empirical methods of heat transfer prediction is given. The influence of a precise definition concerning boundaries of phase flow (it is especially important in condensing inside horizontal tubes), shear stress (friction coefficient) and heat flux on design of heat transfer is shown. The substantiation of boundary conditions of the values of parameters, influencing accuracy of rated relationships, is given. More correct relationships for heat transfer prediction, which showed good convergence with experiments made by different authors, are substantiated in this work.

Keywords: film condensation, heat transfer, plain tube, shear stress

Procedia PDF Downloads 224
5841 Patent License of Transfer Technology: Challenges and Opportunities in Indonesia

Authors: Agung Sujatmiko

Abstract:

One of the purposes of patent licensing was to transfer technology from developed countries to developing countries. For this reason, the role of the patent license agreement was very important and had a function as a tool to achieve technological development. This goal was very good, but in fact, many problems and obstacles arose in its implementation, so the technology transfer that had been implemented had not given good results. For this reason, it was necessary to find a solution so that technology could switch properly. The problem approach used the statutory and conceptual approaches. The analysis used was deductive by analyzing general laws and regulations and then concluding. Several regulations related to technology transfer were the main source to find answers to why technology transfer was difficult to achieve and what caused it. Once the cause was known, a solution would be sought.

Keywords: license, patent, technology, tie in clause

Procedia PDF Downloads 68
5840 The Study of Sintered Wick Structure of Heat Pipes with Excellent Heat Transfer Capabilities

Authors: Im-Nam Jang, Yong-Sik Ahn

Abstract:

In this study sintered wick was formed in a heat pipe through the process of sintering a mixture of copper powder with particle sizes of 100μm and 200μm, mixed with a pore-forming agent. The heat pipe's thermal resistance, which affects its heat transfer efficiency, is determined during manufacturing according to powder type, thickness of the sintered wick, and filling rate of the working fluid. Heat transfer efficiency was then tested at various inclination angles (0°, 45°, 90°) to evaluate the performance of heat pipes. Regardless of the filling amount and test angle, the 200μm copper powder type exhibited superior heat transfer efficiency compared to the 100μm type. After analyzing heat transfer performance at various filling rates between 20% and 50%, it was determined that the heat pipe's optimal heat transfer capability occurred at a working fluid filling rate of 30%. The width of the wick was directly related to the heat transfer performance.

Keywords: heat pipe, heat transfer performance, effective pore size, capillary force, sintered wick

Procedia PDF Downloads 34
5839 Diversity and Intensity of International Technology Transfer and their Impacts on Organizational Performance

Authors: Seongryong Kang, Woonjin Kim, Sungjoo Lee

Abstract:

Under the environment of fierce competition and globalized economy, international technology collaboration has gained increasing attention as a way to improve innovation efficiency. While international technology transfer helps a firm to acquire necessary technology in a short period of time, it also has a risk; embedding external technology from overseas partners may cause a transaction cost due to the regional, cultural and language barriers, which tend to offset the benefits of such transfer. Though a number of previous studies have focused on the effects of technology in-transfer on firm performance, few have conducted in the context of international technology transfer. To fill this gap, this study aims to investigate the impact of international technology in-transfer on firm performance – both innovation and financial performance, with a particular emphasis on the diversity and intensity of such transfer. To do this, we adopted technology balance payment (TBP) data of Korean firms from 2010 to 2011, where an intermediate regression analysis was used to identify the intermediate effects of absorptive capacity. The analysis results indicate that i) the diversity and intensity of international technology transfer influence innovation performance by improving R&D capability positively; and ii) the diversity has a positive impact but the intensity has a negative impact on financial performance through the intermediation of R&D intensity. The research findings are expected to provide meaningful implications for establishing global technology strategy and developing policy programs to facilitate technology transfer.

Keywords: diversity, intensity, international technology acquisition, performance, technology transfer

Procedia PDF Downloads 342
5838 The Importance of Fire Safety in Egypt

Authors: Omar Shakra

Abstract:

This paper contains a huge number of benefits that we can use it in several places and times in fire safety protection in the Middle East especially in Egypt . People here in Egypt did not consider the safety and fire protection as important as it is. But on the other hand, its very important for them to contain the fire systems and safety in every facility, the companies , hospitals , police stations , and even the super markets must use the fire system. It makes the facility safe to the visitors while they are using it.From my point of view as the owner Fire Safety Company called Deluge Egypt , i can say that not all of the companies use the fire system protection according to the high cost they prefer to build their company without the protection, and this is make the building totally unsafe to be used from the visitors or client.So, i am looking for new methods and technology to invest in Egypt, and this is through attending this Conference and let the audiences know more about the services i provide and [to let them know about the importance of the Fire Safety in Egypt. The Objectives of my research 1- The system that i used in my Company. 2- The benefits of the Fire System Protection. 3-The importance of the Fire System and safety. 4-The use of the new Technologies. 5-The hardships that i found while having new deals with new clients.

Keywords: fire, system, protection, fire hydrants, security, alarms

Procedia PDF Downloads 75
5837 Public Bus Transport Passenger Safety Evaluations in Ghana: A Phenomenological Constructivist Exploration

Authors: Enoch F. Sam, Kris Brijs, Stijn Daniels, Tom Brijs, Geert Wets

Abstract:

Notwithstanding the growing body of literature that recognises the importance of personal safety to public transport (PT) users, it remains unclear what PT users consider regarding their safety. In this study, we explore the criteria PT users in Ghana use to assess bus safety. This knowledge will afford a better understanding of PT users’ risk perceptions and assessments which may contribute to theoretical models of PT risk perceptions. We utilised phenomenological research methodology, with data drawn from 61 purposively sampled participants. Data collection (through focus group discussions and in-depth interviews) and analyses were done concurrently to the point of saturation. Our inductive data coding and analyses through the constant comparison and content analytic techniques resulted in 4 code categories (conceptual dimensions), 27 codes (safety items/criteria), and 100 quotations (data segments). Of the number of safety criteria participants use to assess bus safety, vehicle condition, driver’s marital status, and transport operator’s safety records were the most considered. With each criterion, participants rightly demonstrated its respective relevance to bus safety. These findings imply that investment in and maintenance of safer vehicles, and responsible and safety-conscious drivers, and prioritization of passengers’ safety are key-targets for public bus/minibus operators in Ghana.

Keywords: safety evaluations, public bus/minibus, passengers, phenomenology, Ghana

Procedia PDF Downloads 303
5836 A Practical Model for Managing Beach Safety Focusing on Tourist Drownings in Koh Samui, Thailand

Authors: Siyathorn Khunon, Thanawit Buafai

Abstract:

This paper aims to investigate management of beach safety with a focus on tourist drownings in Samui. The data collected in this investigation will then lead to the proposal of a practical management model suitable for use in Samui. Qualitative research was conducted in the following manner: nine stakeholders from local government organizations and tourism businesses were interviewed in-depth. Additionally, a best practice case study from Phuket was applied to analyze beach safety. Twelve foreign tourists were also interviewed. Then, a focus group comprised of 32 people was used to determine practical solutions for enhancing tourists’ safety on the beach in Samui. A steering committee to coordinate between public and private organizations was proposed to manage and enhance tourists’ safety. A practical model is proposed to increase the safety level of tourists in Samui

Keywords: beach safety, drowning, tourist, Samui

Procedia PDF Downloads 249
5835 The Framework of System Safety for Multi Human-in-The-Loop System

Authors: Hideyuki Shintani, Ichiro Koshijima

Abstract:

In Cyber Physical System (CPS), if there are a large number of persons in the process, a role of person in CPS might be different comparing with the one-man system. It is also necessary to consider how Human-in-The-Loop Cyber Physical Systems (HiTLCPS) ensure safety of each person in the loop process. In this paper, the authors discuss a system safety framework with an illustrative example with STAMP model to clarify what point for safety should be considered and what role of person in the should have.

Keywords: cyber-physical-system, human-in-the-loop, safety, STAMP model

Procedia PDF Downloads 308
5834 Comparison of Particle Size for ɑ(Alpha) Fe2O3 and ɤ(Gamma)Fe2O3 on Heat Transfer Performance in an Copper Oscillating Heat Pipe

Authors: Hamid Reza Goshayeshi

Abstract:

The effect of ɑ(alpha) Fe2O3 and ɤ(gamma)Fe2O3 particles on the heat transfer performance of an oscillating heat pipe was investigated experimentally. Kerosene was used as the base fluid for the OHP. Six size particles with average diameters of 10 nm, 20 nm, and 30 nm ɑFe2O3 and ɤFe2O3 were investigated, respectively. Experimental results show that the ɤFe2O3 particles added in the OHP significantly affect the heat transfer performance. When the OHP was charged with kerosene and 20 nm ɤ Fe2O3 particles, the OHP can achieve the best heat transfer performance among six particles investigated in this research.

Keywords: copper oscillating heat pipe, heat transfer, flow, comparison of ɑ(alpha)Fe2O3 and ɤ(gamma)Fe2O3, increase heat transfer

Procedia PDF Downloads 294
5833 Approach to Functional Safety-Compliant Design of Electric Power Steering Systems for Commercial Vehicles

Authors: Hyun Chul Koag, Hyun-Sik Ahn

Abstract:

In this paper, we propose a design approach for the safety mechanism of an actuator used in a commercial vehicle’s EPS system. As the number of electric/electronic system in a vehicle increases, the importance of the functional safety has been receiving much attention. EPS(Electric Power Steering) systems for commercial vehicles require large power than passenger vehicles, and hence, dual motor can be applied to get more torque. We show how to formulate the development process for the design of hardware and software of an EPS system using dual motors. A lot of safety mechanisms for the processor, sensors, and memory have been suggested, however, those for actuators have not been fully researched. It is shown by metric analyses that the target ASIL(Automotive Safety Integrated Level) is satisfied in the point of view of hardware of EPS controller.

Keywords: safety mechanism, functional safety, commercial vehicles, electric power steering

Procedia PDF Downloads 367
5832 Heavy Liquid Metal Coolant – the Key Safety Element in the Complex of New Nuclear Energy Technologies

Authors: A. Orlov, V. Rachkov

Abstract:

The future of Nuclear Energetics is seen in fast reactors with inherent safety working in the closed nuclear fuel cycle. The concept of inherent safety, which lies in deterministic elimination of the most severe accidents due to inherent properties of the reactor rather than through building up engineered barriers, is a cornerstone of success in ensuring safety and economic efficiency of future Nuclear Energetics. The focus of this paper is one of the key elements of inherent safety - the lead coolant of a nuclear reactor. Advantages of lead coolant for reactor application, influence on safety are reviewed. BREST-OD-300 fast reactor, currently being developed in Russia withing the “Proryv” Project utilizes lead coolant and a special set of measures and devices, called technology of lead coolant that ensures safe operation in a wide range of temperatures. Here these technological elements are reviewed, and current progress in their development is discussed.

Keywords: BREST-OD-300. , fast reactor, inherent safety, lead coolant

Procedia PDF Downloads 127
5831 Heat Transfer Characteristics on Blade Tip with Unsteady Wake

Authors: Minho Bang, Seok Min Choi, Jun Su Park, Hokyu Moon, Hyung Hee Cho

Abstract:

Present study investigates the effect of unsteady wakes on heat transfer in blade tip. Heat/mass transfer was measured in blade tip region depending on a variety of strouhal number by naphthalene sublimation technique. Naphthalene sublimation technique measures heat transfer using a heat/mass transfer analogy. Experiments are performed in linear cascade which is composed of five turbine blades and rotating rods. Strouhal number of inlet flow are changed ranging from 0 to 0.22. Reynolds number is 100,000 based on 11.4 m/s of outlet flow and axial chord length. Three different squealer tip geometries such as base squealer tip, vertical rib squealer tip, and camber line squealer tip are used to study how unsteady wakes affect heat transfer on a blade tip. Depending on squealer tip geometry, different flow patterns occur on a blade tip. Also, unsteady wakes cause reduced tip leakage flow and turbulent flow. As a result, as strouhal number increases, heat/mass transfer coefficients decrease due to the reduced leakage flow. As strouhal number increases, heat/ mass transfer coefficients on a blade tip increase in vertical rib squealer tip.

Keywords: gas turbine, blade tip, heat transfer, unsteady wakes

Procedia PDF Downloads 347
5830 Fluid Flow and Heat Transfer Characteristics Investigation in Spray Cooling Systems Using Nanofluids

Authors: Lee Derk Huan, Nur Irmawati

Abstract:

This paper aims to investigate the heat transfer and fluid flow characteristics of nanofluids used in spray cooling systems. The effect of spray height, type of nanofluids and concentration of nanofluids are numerically investigated. Five different nanofluids such as AgH2O, Al2O3, CuO, SiO2 and TiO2 with volume fraction range of 0.5% to 2.5% are used. The results revealed that the heat transfer performance decreases as spray height increases. It is found that TiO2 has the highest transfer coefficient among other nanofluids. In dilute spray conditions, low concentration of nanofluids is observed to be more effective in heat removal in a spray cooling system.

Keywords: numerical investigation, spray cooling, heat transfer, nanofluids

Procedia PDF Downloads 444
5829 A Fuzzy TOPSIS Based Model for Safety Risk Assessment of Operational Flight Data

Authors: N. Borjalilu, P. Rabiei, A. Enjoo

Abstract:

Flight Data Monitoring (FDM) program assists an operator in aviation industries to identify, quantify, assess and address operational safety risks, in order to improve safety of flight operations. FDM is a powerful tool for an aircraft operator integrated into the operator’s Safety Management System (SMS), allowing to detect, confirm, and assess safety issues and to check the effectiveness of corrective actions, associated with human errors. This article proposes a model for safety risk assessment level of flight data in a different aspect of event focus based on fuzzy set values. It permits to evaluate the operational safety level from the point of view of flight activities. The main advantages of this method are proposed qualitative safety analysis of flight data. This research applies the opinions of the aviation experts through a number of questionnaires Related to flight data in four categories of occurrence that can take place during an accident or an incident such as: Runway Excursions (RE), Controlled Flight Into Terrain (CFIT), Mid-Air Collision (MAC), Loss of Control in Flight (LOC-I). By weighting each one (by F-TOPSIS) and applying it to the number of risks of the event, the safety risk of each related events can be obtained.

Keywords: F-topsis, fuzzy set, flight data monitoring (FDM), flight safety

Procedia PDF Downloads 144
5828 Estimation of Natural Convection Heat Transfer from Plate-Fin Heat Sinks in a Closed Enclosure

Authors: Han-Taw Chen, Chung-Hou Lai, Tzu-Hsiang Lin, Ge-Jang He

Abstract:

This study applies the inverse method and three-dimensional CFD commercial software in conjunction with the experimental temperature data to investigate the heat transfer and fluid flow characteristics of the plate-fin heat sink in a closed rectangular enclosure for various values of fin height. The inverse method with the finite difference method and the experimental temperature data is applied to determine the heat transfer coefficient. The k-ε turbulence model is used to obtain the heat transfer and fluid flow characteristics within the fins. To validate the accuracy of the results obtained, the comparison of the average heat transfer coefficient is made. The calculated temperature at selected measurement locations on the plate-fin is also compared with experimental data.

Keywords: inverse method, FLUENT, k-ε model, heat transfer characteristics, plate-fin heat sink

Procedia PDF Downloads 442
5827 Reducing Crash Risk at Intersections with Safety Improvements

Authors: Upal Barua

Abstract:

Crash risk at intersections is a critical safety issue. This paper examines the effectiveness of removing an existing off-set at an intersection by realignment, in reducing crashes. Empirical Bayes method was applied to conduct a before-and-after study to assess the effect of this safety improvement. The Transportation Safety Improvement Program in Austin Transportation Department completed several safety improvement projects at high crash intersections with a view to reducing crashes. One of the common safety improvement techniques applied was the realignment of intersection approaches removing an existing off-set. This paper illustrates how this safety improvement technique is applied at a high crash intersection from inception to completion. This paper also highlights the significant crash reductions achieved from this safety improvement technique applying Empirical Bayes method in a before-and-after study. The result showed that realignment of intersection approaches removing an existing off-set can reduce crashes by 53%. This paper also features the state of the art techniques applied in planning, engineering, designing and construction of this safety improvement, key factors driving the success, and lessons learned in the process.

Keywords: crash risk, intersection, off-set, safety improvement technique, before-and-after study, empirical Bayes method

Procedia PDF Downloads 221
5826 Exploring the Meaning of Safety in Acute Mental Health Inpatient Units from the Consumer Perspective

Authors: Natalie Cutler, Lorna Moxham, Moira Stephens

Abstract:

Safety is a priority in mental health services, and no more so than in the acute inpatient setting. Mental health service policies and accreditation frameworks commonly approach safety from a risk reduction or elimination perspective leading to service approaches that are arguably more focused on risk than on safety. An exploration what safety means for people who have experienced admission to an acute mental health inpatient unit is currently under way in Sydney, Australia. Using a phenomenographic research approach, this study is seeking to understand the meaning of safety from the perspective of people who use, rather than those who deliver mental health services. Preliminary findings suggest that the meanings of safety for users of mental health services vary from the meanings inherent in the policies and frameworks that inform how mental health services and mental health practice are delivered. This variance has implications for the physical and environmental design of acute mental health inpatient facilities, the policies and practices, and the education and training of mental health staff in particular nurses, who comprise the majority of the mental health workforce. These variances will be presented, along with their implications for the way quality and safety in mental health services are evaluated.

Keywords: acute inpatient, mental health, nursing, phenomenography, recovery, safety

Procedia PDF Downloads 208
5825 Transfer Knowledge From Multiple Source Problems to a Target Problem in Genetic Algorithm

Authors: Terence Soule, Tami Al Ghamdi

Abstract:

To study how to transfer knowledge from multiple source problems to the target problem, we modeled the Transfer Learning (TL) process using Genetic Algorithms as the model solver. TL is the process that aims to transfer learned data from one problem to another problem. The TL process aims to help Machine Learning (ML) algorithms find a solution to the problems. The Genetic Algorithms (GA) give researchers access to information that we have about how the old problem is solved. In this paper, we have five different source problems, and we transfer the knowledge to the target problem. We studied different scenarios of the target problem. The results showed combined knowledge from multiple source problems improves the GA performance. Also, the process of combining knowledge from several problems results in promoting diversity of the transferred population.

Keywords: transfer learning, genetic algorithm, evolutionary computation, source and target

Procedia PDF Downloads 117
5824 Steady Conjugate Heat Transfer of Two Connected Thermal Systems

Authors: Mohamed El-Sayed Mosaad

Abstract:

An analytic approach is obtained for the steady heat transfer problem of two fluid systems, in thermal communication via heat conduction across a solid wall separating them. The two free convection layers created on wall sides are assumed to be in parallel flow. Fluid-solid interface temperature on wall sides is not prescribed in analysis in advance; rather, determined from conjugate solution among other unknown parameters. The analysis highlights the main conjugation parameters controlling thermal interaction process of involved heat transfer modes. Heat transfer results of engineering importance are obtained.

Keywords: conjugate heat transfer, boundary layer, convection, thermal systems

Procedia PDF Downloads 356
5823 Assessment of Academic Knowledge Transfer Channels in Field of Environment

Authors: Jagul Huma Lashari, Arabella Bhutto

Abstract:

Last few years have shown increased an interest of researchers in knowledge and technology transfer. However, facts show fewer types of knowledge transfer practices in the developing countries. This article focuses on assessment transfer channels of academic research produced by highly qualified academicians working in universities in Sindh offering degrees in field of an Environment in Sindh Pakistan. The academic field has been chosen because in field of the environment there is alarming need of research into practice for sustainable development. Using case study approach; in this research qualitative interviews have been conducted from PhD faculty members working in the universities offering degrees in field of environment. Obtained data is analyzed using descriptive statistics and chi-square test with the help of statistical packages for social sciences (SPSS). Research explored 31 channels of academic knowledge transfer from detailed review of literature and exploratory interviews with participants. Identified knowledge transfer channels have been grouped together in 6 groups of knowledge transfer channels; As knowledge transfer through publications, networking, mobility of researchers, joint research, intellectual property and co-operations. Results revealed that academic knowledge have been transferred through publications, networking, and co-operation. However, less number of academic knowledge has been transferred through groups of knowledge transfer channels such as Intellectual Property and joint research.

Keywords: environment, research knowledge, transfer channels, universities

Procedia PDF Downloads 312
5822 Numerical Analysis of Heat Transfer Enhancement in Heat Exchangers by using Dimpled Tube

Authors: Bader Alhumaidi Alsubaei, Zahid H. Akash, Ali Imam Sunny

Abstract:

The heat transfer coefficient can be improved passively by using a dimpled surface on the tube. The contact area where heat transfer takes place can be enlarged and turbulence will be purposefully produced inside the duct; as a consequence, higher heat transfer quality will be achieved by employing an extended inner or outer surface (dimpled surface). In order to compare the rate and quality of heat transfer between a regular-shaped pipe and a dimpled pipe, a dimpled tube with a fixed dimple radius was created. Numerical analysis of the plain and dimpled pipes was performed using ANSYS. A 23% increase in Nusselt number was seen for dimpled tubes compared to plain tubes. In comparison to plain tubes, dimpled tubes' increase in thermal performance index was found to be between 8% and 10%. An increase in pressure drop of 18% was noted.

Keywords: heat transfer, dimpled tube, CFD, ANSYS

Procedia PDF Downloads 84
5821 Development of Risk Assessment and Occupational Safety Management Model for Building Construction Projects

Authors: Preeda Sansakorn, Min An

Abstract:

In order to be capable of dealing with uncertainties, subjectivities, including vagueness arising in building construction projects, the application of fuzzy reasoning technique based on fuzzy set theory is proposed. This study contributes significantly to the development of a fuzzy reasoning safety risk assessment model for building construction projects that could be employed to assess the risk magnitude of each hazardous event identified during construction, and a third parameter of probability of consequence is incorporated in the model. By using the proposed safety risk analysis methodology, more reliable and less ambiguities, which provide the safety risk management project team for decision-making purposes.

Keywords: safety risk assessment, building construction safety, fuzzy reasoning, construction risk assessment model, building construction projects

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5820 Hohmann Transfer and Bi-Elliptic Hohmann Transfer in TRAPPIST-1 System

Authors: Jorge L. Nisperuza, Wilson Sandoval, Edward. A. Gil, Johan A. Jimenez

Abstract:

In orbital mechanics, an active research topic is the calculation of interplanetary trajectories efficient in terms of energy and time. In this sense, this work concerns the calculation of the orbital elements for sending interplanetary probes in the extrasolar system TRAPPIST-1. Specifically, using the mathematical expressions of the circular and elliptical trajectory parameters, expressions for the flight time and the orbital transfer rate increase between orbits, the orbital parameters and the graphs of the trajectories of Hohmann and Hohmann bi-elliptic for sending a probe from the innermost planet to all the other planets of the studied system, are obtained. The relationship between the orbital transfer rate increments and the relationship between the flight times for the two transfer types is found. The results show that, for all cases under consideration, the Hohmann transfer results to be the least energy and temporary cost, a result according to the theory associated with Hohmann and Hohmann bi-elliptic transfers. Saving in the increase of the speed reaches up to 87% was found, and it happens for the transference between the two innermost planets, whereas the time of flight increases by a factor of up to 6.6 if one makes use of the bi-elliptic transfer, this for the case of sending a probe from the innermost planet to the outermost.

Keywords: bi-elliptic Hohmann transfer, exoplanet, extrasolar system, Hohmann transfer, TRAPPIST-1

Procedia PDF Downloads 166
5819 Exciting Voltage Control for Efficiency Maximization for 2-D Omni-Directional Wireless Power Transfer Systems

Authors: Masato Sasaki, Masayoshi Yamamoto

Abstract:

The majority of wireless power transfer (WPT) systems transfer power in a directional manner. This paper describes a discrete exciting voltage control technique for WPT via magnetic resonant coupling with two orthogonal transmitter coils (2D omni-directional WPT system) which can maximize the power transfer efficiency in response to the change of coupling status. The theory allows the equations of the efficiency of the system to be determined at all the rate of the mutual inductance. The calculated results are included to confirm the advantage to one directional WPT system and the validity of the theory and the equations.

Keywords: wireless power transfer, omni-directional, orthogonal, efficiency

Procedia PDF Downloads 298
5818 Numerical and Experimental Study on Bed-Wall Heat Transfer in Conical Fluidized Bed Combustor

Authors: Ik–Tae Im, H. M. Abdelmotalib, M. A. Youssef, S. B. Young

Abstract:

In this study the flow characteristics and bed-to-wall heat transfer in a gas-solid conical fluidized bed combustor were investigated using both experimental and numerical methods. The computational fluid dynamic (CFD) simulations were carried out using a commercial software, Fluent V6.3. A two-fluid Eulerian-Eulerian model was applied in order to simulate the gas–solid flow and heat transfer in a conical sand-air bed with 30o con angle and 22 cm static bed height. Effect of different fluidizing number varying in the range of 1.5 - 2.3, drag models namely (Syamlal-O’Brien and Gidaspow), and friction viscosity on flow and bed-to-wall heat transfer were analyzed. Both bed pressure drop and heat transfer coefficient increased with increasing inlet gas velocity. The Gidaspow drag model showed a better agreement with experimental results than other drag model. The friction viscosity had no clear effect on both hydrodynamics and heat transfer.

Keywords: computational fluid dynamics, heat transfer coefficient, hydrodynamics, renewable energy

Procedia PDF Downloads 381
5817 Food Safety Management in Riyadh’s Ministry of Health Hospitals

Authors: A. Alrasheed, I. Connerton

Abstract:

Providing patients with safe meals on a daily basis is one of the challenges in the healthcare sector. In Saudi Arabia matters related to food safety and hygiene have been the heart of the Ministry of Health (MOH) and Saudi Food and Drugs Authority (SFDA). The aim of this study is to examine the causes of inadequate implementation of food safety management systems such as HACCP in Riyadh’s MOH hospitals. By the law, food safety must be managed using a documented, HACCP based approach, and food handlers must be appropriately trained in food safety. Food handlers in Saudi Arabia are not required to provide a certificate or attend a food handling training course even in healthcare sectors. Since food safety and hygiene issues are of increasing importance for Saudi Arabian health decision makers, the SFDA has been established to apply food hygiene requirements in all food operations. It should be pointed out that the implications of food outbreaks on the whole society may potentially go beyond individual health impacts but also impact on the Nation’s health and bring about economic repercussions.

Keywords: food safety, patient, hospital, HACCP

Procedia PDF Downloads 850
5816 A Case Study Approach on Co-Constructing the Idea of 'Safety' with Children

Authors: Beng Zhen Yeow

Abstract:

In most work that involves children, the voice of the children is often not heard. This is ironic since a lot of discussions might involve their welfare and safety. It might seem natural that the professionals should hear from them about what they wish for instead of deciding what is best for them. However, this, unfortunately, might be more the exception than the norm in most case and hence in many instances, children are merely 'subjects' in conversations about safety instead of active participants in the construction or creation of safety in the family. There might be many reasons why it does not happen in our work. Firstly, professionals have learnt how to 'socialise' into their professional roles and hence in the process become 'un-childlike'. Secondly, there is also a lack of professional training with regards to how to talk with children. Finally, there might be also a lack of concrete tools and techniques that are developed to facilitate the process. In this paper, the case study method is used to show how the idea of safety could be concretised and discussed with children and their family members, and hence making them active participants and co-creators of their own safety. Specific skills and techniques are highlighted through the case study. In this case, there was improvement in outcomes like no repeated offence or abuse. In addition, children were also able to advocate for their own safety after six months of intervention and how the family members were able to explicitly say what they can do to improve safety. The professionals in the safety network reported significant improvements. On top of that, the abused child who was removed due to child protection concerns, had verbalized observations of change in mother’s parenting abilities, and has requested for home leave to begin due to ownership of safety planning and having confidence to co-create safety for her siblings and herself together with the professionals in the safety network. Children becoming active participants in the co-creation of safety not only serve the purpose in allowing them to own a 'voice' but at the same time, give them greater confidence to protect themselves at home and in other contexts outside of home.

Keywords: partnering for safety, collaborative social work, family and systemic psychotherapy, child protection

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5815 Mathematical Modeling of Skin Condensers for Domestic Refrigerator

Authors: Nitin Ghule, S. G. Taji

Abstract:

A mathematical model of hot-wall condensers used in refrigerators is presented. The model predicts the heat transfer characteristics of condenser and the effects of various design and operating parameters on condenser tube length and capacity. A finite element approach was used to model the condenser. The condenser tube is divided into elemental units, with each element consisting of adhesive tape, refrigerant tube and outer metal sheet. The heat transfer characteristics of each section are then analyzed by considering the heat transfer through the tube wall, tape and the outer sheet. Variations in inner heat transfer coefficient and pressure drop are considered depending on temperature, fluid phase, type of flow and orientation of tube. Variation in outer heat transfer coefficient is also taken into account. Various materials were analysed for the tube, tape and outer sheet.

Keywords: condenser, domestic refrigerator, heat transfer, mathematical model

Procedia PDF Downloads 438
5814 The Effect of Adding CuO Nanoparticles on Boiling Heat Transfer Enhancement in Horizontal Flattened Tubes

Authors: M. A. Akhavan-Behabadi, M. Najafi, A. Abbasi

Abstract:

An empirical investigation was performed in order to study the heat transfer characteristics of R600a flow boiling inside horizontal flattened tubes and the simultaneous effect of nanoparticles on boiling heat transfer in flattened channel. Round copper tubes of 8.7 mm I.D. were deformed into flattened shapes with different inside heights of 6.9, 5.5, and 3.4 mm as test areas. The effect of different parameters such as mass flux, vapor quality and inside height on heat transfer coefficient was studied. Flattening the tube caused a significant enhancement in heat transfer performance, so that the maximum augmentation ratio of 163% was obtained in flattened channel with lowest internal height. A new correlation was developed based on the present experimental data to predict the heat transfer coefficient in flattened tubes. This correlation estimated 90% of the entire database within ±20%. The best flat channel with the point of view of heat transfer performance was selected to study the effect of nanoparticle on heat transfer enhancement. Four homogenized mixtures containing 1% weight fraction of R600a/oil with different CuO nanoparticles concentration including 0.5%, 1% and 1.5% mass fraction of R600a/oil/CuO were studied. Observations show that heat transfer was improved by adding nanoparticles, which lead to maximum enhancement of 79% compare to the pure refrigerant at the same test condition.

Keywords: nano fluids, heat transfer, flattend tube, transport phenomena

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5813 Heat Transfer Enhancement Using Aluminium Oxide Nanofluid: Effect of the Base Fluid

Authors: M. Amoura, M. Benmoussa, N. Zeraibi

Abstract:

The flow and heat transfer is an important phenomenon in engineering systems due to its wide application in electronic cooling, heat exchangers, double pane windows etc.. The enhancement of heat transfer in these systems is an essential topic from an energy saving perspective. Lower heat transfer performance when conventional fluids, such as water, engine oil and ethylene glycol are used hinders improvements in performance and causes a consequent reduction in the size of such systems. The use of solid particles as an additive suspended into the base fluid is a technique for heat transfer enhancement. Therefore, the heat transfer enhancement in a horizontal circular tube that is maintained at a constant temperature under laminar regime has been investigated numerically. A computational code applied to the problem by use of the finite volume method was developed. Nanofluid was made by dispersion of Al2O3 nanoparticles in pure water and ethylene glycol. Results illustrate that the suspended nanoparticles increase the heat transfer with an increase in the nanoparticles volume fraction and for a considered range of Reynolds numbers. On the other hand, the heat transfer is very sensitive to the base fluid.

Keywords: Al2O3 nanoparticles, circular tube, heat transfert enhancement, numerical simulation

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