Search results for: experimental approach
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 19711

Search results for: experimental approach

5191 Geometrical Fluid Model for Blood Rheology and Pulsatile Flow in Stenosed Arteries

Authors: Karan Kamboj, Vikramjeet Singh, Vinod Kumar

Abstract:

Considering blood to be a non-Newtonian Carreau liquid, this indirect numerical model investigates the pulsatile blood flow in a constricted restricted conduit that has numerous gentle stenosis inside the view of an increasing body speed. Asymptotic answers are obtained for the flow rate, pressure inclination, speed profile, sheer divider pressure, and longitudinal impedance to stream after the use of the twofold irritation approach to the problem of the succeeding non-straight limit esteem. It has been observed that the speed of the blood increases when there is an increase in the point of tightening of the conduit, the body speed increase, and the power regulation file. However, this rheological manner of behaving changes to one of longitudinal impedance to stream and divider sheer pressure when each of the previously mentioned boundaries increases. It has also been seen that the sheer divider pressure in the bloodstream greatly increases when there is an increase in the maximum depth of the stenosis but that it significantly decreases when there is an increase in the pulsatile Reynolds number. This is an interesting phenomenon. The assessments of the amount of growth in the longitudinal resistance to flow increase overall with the increment of the maximum depth of the stenosis and the Weissenberg number. Additionally, it is noted that the average speed of blood increases noticeably with the growth of the point of tightening of the corridor, and body speed increases border. This is something that can be observed.

Keywords: geometry of artery, pulsatile blood flow, numerous stenosis

Procedia PDF Downloads 93
5190 Competency-Based Social Work Practice and Challenges in Child Case Management: Studies in the Districts Social Welfare Services, Malaysia

Authors: Sopian Brahim, Mohd Suhaimi Mohamad, Ezarina Zakaria, Norulhuda Sarnon

Abstract:

This study aims to explore the practical experience of child welfare case workers and professionalism in the child case management in Malaysia. This paper discusses the specific social work practice competency and challenges faced by child caseworkers in the fieldwork. This research is qualitative with Grounded Theory approach. Four sessions of Focused Group Discussion (FGD) have been conducted involving a total of 27 caseworkers (child protector and probation officers) in the Klang Valley. The study found that the four basic principles of knowledge in child case management namely: 1. Knowledge in child case management, 2. Professional values of caseworkers towards children, 3. skills in managing cases, and 4. Culturally competence practice in child case managemenr. In addition, major challenges faced in the child case management are the capacity and commitment of the family in children's rehabilitation program, the credibility of the case worker are being challenge and challenges in support system from intra and inter-agency. This study is important for policy makers to take into account the capacity and needs of the child's case worker in accordance with national social work competency framework thereby improving case management services for children more systematically in line with national standards.

Keywords: social work practice, child case management, competency-based knowledge, professionalism

Procedia PDF Downloads 330
5189 Stability Analysis of Rock Tunnel Subjected to Internal Blast Loading

Authors: Mohammad Zaid, Md. Rehan Sadique

Abstract:

Underground structures are an integral part of urban infrastructures. Tunnels are being used for the transportation of humans and goods from distance to distance. Terrorist attacks on underground structures such as tunnels have resulted in the improvement of design methodologies of tunnels. The design of underground tunnels must include anti-terror design parameters. The study has been carried out to analyse the rock tunnel when subjected to internal blast loading. The finite element analysis has been carried out for 30m by 30m of the cross-section of the tunnel and 35m length of extrusion of the rock tunnel model. The effect of tunnel diameter and overburden depth of tunnel has been studied under internal blast loading. Four different diameters of tunnel considered are 5m, 6m, 7m, and 8m, and four different overburden depth of tunnel considered are 5m, 7.5m, 10m, and 12.5m. The mohr-coulomb constitutive material model has been considered for the Quartzite rock. A concrete damage plasticity model has been adopted for concrete tunnel lining. For the trinitrotoluene (TNT) Jones-Wilkens-Lee (JWL) material model has been considered. Coupled-Eulerian-Lagrangian (CEL) approach for blast analysis has been considered in the present study. The present study concludes that a shallow tunnel having smaller diameter needs more attention in comparison to blast resistant design of deep tunnel having a larger diameter. Further, in the case of shallow tunnels, more bulging has been observed, and a more substantial zone of rock has been affected by internal blast loading.

Keywords: finite element method, blast, rock, tunnel, CEL, JWL

Procedia PDF Downloads 144
5188 Development of Sustainable Building Environmental Model (SBEM) in Hong Kong

Authors: Kwok W. Mui, Ling T. Wong, F. Xiao, Chin T. Cheung, Ho C. Yu

Abstract:

This study addresses a concept of the Sustainable Building Environmental Model (SBEM) developed to optimize energy consumption in air conditioning and ventilation (ACV) systems without any deterioration of indoor environmental quality (IEQ). The SBEM incorporates two main components: an adaptive comfort temperature control module (ACT) and a new carbon dioxide demand control module (nDCV). These two modules take an innovative approach to maintain satisfaction of the Indoor Environmental Quality (IEQ) with optimum energy consumption, they provide a rational basis of effective control. A total of 2133 sets of measurement data of indoor air temperature (Ta), relative humidity (Rh) and carbon dioxide concentration (CO2) were conducted in some Hong Kong offices to investigate the potential of integrating the SBEM. A simulation was used to evaluate the dynamic performance of the energy and air conditioning system with the integration of the SBEM in an air-conditioned building. It allows us make a clear picture of the control strategies and performed any pre-tuned of controllers before utilized in real systems. With the integration of SBEM, it was able to save up to 12.3% in simulation and 15% in field measurement of overall electricity consumption, and maintain the average carbon dioxide concentration within 1000ppm and occupant dissatisfaction in 20%.

Keywords: sustainable building environmental model (SBEM), adaptive comfort temperature (ACT), new demand control ventilation (nDCV), energy saving

Procedia PDF Downloads 633
5187 Mechanisms Underlying Comprehension of Visualized Personal Health Information: An Eye Tracking Study

Authors: Da Tao, Mingfu Qin, Wenkai Li, Tieyan Wang

Abstract:

While the use of electronic personal health portals has gained increasing popularity in the healthcare industry, users usually experience difficulty in comprehending and correctly responding to personal health information, partly due to inappropriate or poor presentation of the information. The way personal health information is visualized may affect how users perceive and assess their personal health information. This study was conducted to examine the effects of information visualization format and visualization mode on the comprehension and perceptions of personal health information among personal health information users with eye tracking techniques. A two-factor within-subjects experimental design was employed, where participants were instructed to complete a series of personal health information comprehension tasks under varied types of visualization mode (i.e., whether the information visualization is static or dynamic) and three visualization formats (i.e., bar graph, instrument-like graph, and text-only format). Data on a set of measures, including comprehension performance, perceptions, and eye movement indicators, were collected during the task completion in the experiment. Repeated measure analysis of variance analyses (RM-ANOVAs) was used for data analysis. The results showed that while the visualization format yielded no effects on comprehension performance, it significantly affected users’ perceptions (such as perceived ease of use and satisfaction). The two graphic visualizations yielded significantly higher favorable scores on subjective evaluations than that of the text format. While visualization mode showed no effects on users’ perception measures, it significantly affected users' comprehension performance in that dynamic visualization significantly reduced users' information search time. Both visualization format and visualization mode had significant main effects on eye movement behaviors, and their interaction effects were also significant. While the bar graph format and text format had similar time to first fixation across dynamic and static visualizations, instrument-like graph format had a larger time to first fixation for dynamic visualization than for static visualization. The two graphic visualization formats yielded shorter total fixation duration compared with the text-only format, indicating their ability to improve information comprehension efficiency. The results suggest that dynamic visualization can improve efficiency in comprehending important health information, and graphic visualization formats were favored more by users. The findings are helpful in the underlying comprehension mechanism of visualized personal health information and provide important implications for optimal design and visualization of personal health information.

Keywords: eye tracking, information comprehension, personal health information, visualization

Procedia PDF Downloads 101
5186 Spatial Architecture Impact in Mediation Open Circuit Voltage Control of Quantum Solar Cell Recovery Systems

Authors: Moustafa Osman Mohammed

Abstract:

The photocurrent generations are influencing ultra-high efficiency solar cells based on self-assembled quantum dot (QD) nanostructures. Nanocrystal quantum dots (QD) provide a great enhancement toward solar cell efficiencies through the use of quantum confinement to tune absorbance across the solar spectrum enabled multi-exciton generation. Based on theoretical predictions, QDs have potential to improve systems efficiency in approximate regular electrons excitation intensity greater than 50%. In solar cell devices, an intermediate band formed by the electron levels in quantum dot systems. The spatial architecture is exploring how can solar cell integrate and produce not only high open circuit voltage (> 1.7 eV) but also large short-circuit currents due to the efficient absorption of sub-bandgap photons. In the proposed QD system, the structure allows barrier material to absorb wavelengths below 700 nm while multi-photon processes in the used quantum dots to absorb wavelengths up to 2 µm. The assembly of the electronic model is flexible to demonstrate the atoms and molecules structure and material properties to tune control energy bandgap of the barrier quantum dot to their respective optimum values. In terms of energy virtual conversion, the efficiency and cost of the electronic structure are unified outperform a pair of multi-junction solar cell that obtained in the rigorous test to quantify the errors. The milestone toward achieving the claimed high-efficiency solar cell device is controlling the edge causes of energy bandgap between the barrier material and quantum dot systems according to the media design limits. Despite this remarkable potential for high photocurrent generation, the achievable open-circuit voltage (Voc) is fundamentally limited due to non-radiative recombination processes in QD solar cells. The orientation of voltage recovery system is compared theoretically with experimental Voc variation in mediation upper–limit obtained one diode modeling form at the cells with different bandgap (Eg) as classified in the proposed spatial architecture. The opportunity for improvement Voc is valued approximately greater than 1V by using smaller QDs through QD solar cell recovery systems as confined to other micro and nano operations states.

Keywords: nanotechnology, photovoltaic solar cell, quantum systems, renewable energy, environmental modeling

Procedia PDF Downloads 149
5185 Restructuring Cameroon's Educational System: The Value of Inclusive Education for Children with Visual Impairment

Authors: Samanta Tiague, Igor Michel Gachig

Abstract:

The practice of inclusive education within general education classrooms is becoming more prevalent in Cameroon. In this context, quality Education is an important driver of the development agenda in this era of global sustainable development. This requires that the Cameroon’s educational system be strategically restructured to provide every citizen with the needed quality education for sustainable development. This study thus examined the need for the restructuring of the Cameroon educational system towards inclusive education as a target of the Sustainable Development Goal #4 (Ensure Quality Education), from a critical disability theory perspective. Special focus was on the education of children with visual impairment in the early childhood classroom. This study is suggesting a model design of responsive and contextual inclusive education policies, and the provision of quality human, material and financial educational resources to support the improvement of curriculums and inclusive instructional strategies. This paper is therefore designed as a basic starting point for early childhood educators with limited to no experience in working with students having visual impairments. Ultimately, this work represents a contribution to early childhood educators toward understanding visual impairment challenges and innovative practices to approach accessibility in a meaningful way to students in Cameroon. This is important to achieve quality education due to the peculiar nature of the educational needs of children with visual impairment, toward attainment of the global sustainable development agenda.

Keywords: early childhood educators, inclusive education, sustainable development, visual impairment

Procedia PDF Downloads 141
5184 The Effective Use of the Network in the Distributed Storage

Authors: Mamouni Mohammed Dhiya Eddine

Abstract:

This work aims at studying the exploitation of high-speed networks of clusters for distributed storage. Parallel applications running on clusters require both high-performance communications between nodes and efficient access to the storage system. Many studies on network technologies led to the design of dedicated architectures for clusters with very fast communications between computing nodes. Efficient distributed storage in clusters has been essentially developed by adding parallelization mechanisms so that the server(s) may sustain an increased workload. In this work, we propose to improve the performance of distributed storage systems in clusters by efficiently using the underlying high-performance network to access distant storage systems. The main question we are addressing is: do high-speed networks of clusters fit the requirements of a transparent, efficient and high-performance access to remote storage? We show that storage requirements are very different from those of parallel computation. High-speed networks of clusters were designed to optimize communications between different nodes of a parallel application. We study their utilization in a very different context, storage in clusters, where client-server models are generally used to access remote storage (for instance NFS, PVFS or LUSTRE). Our experimental study based on the usage of the GM programming interface of MYRINET high-speed networks for distributed storage raised several interesting problems. Firstly, the specific memory utilization in the storage access system layers does not easily fit the traditional memory model of high-speed networks. Secondly, client-server models that are used for distributed storage have specific requirements on message control and event processing, which are not handled by existing interfaces. We propose different solutions to solve communication control problems at the filesystem level. We show that a modification of the network programming interface is required. Data transfer issues need an adaptation of the operating system. We detail several propositions for network programming interfaces which make their utilization easier in the context of distributed storage. The integration of a flexible processing of data transfer in the new programming interface MYRINET/MX is finally presented. Performance evaluations show that its usage in the context of both storage and other types of applications is easy and efficient.

Keywords: distributed storage, remote file access, cluster, high-speed network, MYRINET, zero-copy, memory registration, communication control, event notification, application programming interface

Procedia PDF Downloads 213
5183 Design, Numerical Simulation, Fabrication and Physical Experimentation of the Tesla’s Cohesion Type Bladeless Turbine

Authors: M.Sivaramakrishnaiah, D. S .Nasan, P. V. Subhanjeneyulu, J. A. Sandeep Kumar, N. Sreenivasulu, B. V. Amarnath Reddy, B. Veeralingam

Abstract:

Design, numerical simulation, fabrication, and physical experimentation of the Tesla’s Bladeless centripetal turbine for generating electrical power are presented in this research paper. 29 Pressurized air combined with water via a nozzle system is made to pass tangentially through a set of parallel smooth discs surfaces, which impart rotational motion to the discs fastened common shaft for the power generation. The power generated depends upon the fluid speed parameter leaving the nozzle inlet. Physically due to laminar boundary layer phenomena at smooth disc surface, the high speed fluid layers away from the plate moving against the low speed fluid layers nearer to the plate develop a tangential drag from the viscous shear forces. This compels the nearer layers to drag along with the high layers causing the disc to spin. Solid Works design software and fluid mechanics and machine elements design theories was used to compute mechanical design specifications of turbine parts like 48 mm diameter discs, common shaft, central exhaust, plenum chamber, swappable nozzle inlets, etc. Also, ANSYS CFX 2018 was used for the numerical 2 simulation of the physical phenomena encountered in the turbine working. When various numerical simulation and physical experimental results were verified, there is good agreement between them 6, both quantitatively and qualitatively. The sources of input and size of the blades may affect the power generated and turbine efficiency, respectively. The results may change if there is a change in the fluid flowing between the discs. The inlet fluid pressure versus turbine efficiency and the number of discs versus turbine power studies based on both results were carried out to develop the 8 relationships between the inlet and outlet parameters of the turbine. The present research work obtained the turbine efficiency in the range of 7-10%, and for this range; the electrical power output generated was 50-60 W.

Keywords: tesla turbine, cohesion type bladeless turbine, boundary layer theory, cohesion type bladeless turbine, tangential fluid flow, viscous and adhesive forces, plenum chamber, pico hydro systems

Procedia PDF Downloads 83
5182 The Amount of Information Processing and Balance Performance in Children: The Dual-Task Paradigm

Authors: Chin-Chih Chiou, Tai-Yuan Su, Ti-Yu Chen, Wen-Yu Chiu, Chungyu Chen

Abstract:

The purpose of this study was to investigate the effect of reaction time (RT) or balance performance as the number of stimulus-response choices increases, the amount of information processing of 0-bit and 1-bit conditions based on Hick’s law, using the dual-task design. Eighteen children (age: 9.38 ± 0.27 years old) were recruited as the participants for this study, and asked to assess RT and balance performance separately and simultaneously as following five conditions: simple RT (0-bit decision), choice RT (1-bit decision), single balance control, balance control with simple RT, and balance control with choice RT. Biodex 950-300 balance system and You-Shang response timer were used to record and analyze the postural stability and information processing speed (RT) respectively for the participants. Repeated measures one-way ANOVA with HSD post-hoc test and 2 (balance) × 2 (amount of information processing) repeated measures two-way ANOVA were used to test the parameters of balance performance and RT (α = .05). The results showed the overall stability index in the 1-bit decision was lower than in 0-bit decision, and the mean deflection in the 1-bit decision was lower than in single balance performance. Simple RTs were faster than choice RTs both in single task condition and dual task condition. It indicated that the chronometric approach of RT could use to infer the attention requirement of the secondary task. However, this study did not find that the balance performance is interfered for children by the increasing of the amount of information processing.

Keywords: capacity theory, reaction time, Hick’s law, balance

Procedia PDF Downloads 446
5181 Identification of Social Responsibility Factors within Mega Construction Projects

Authors: Ali Alotaibi, Francis Edum-Fotwe, Andrew Price /

Abstract:

Mega construction projects create buildings and major infrastructure to respond to work and life requirements while playing a vital role in promoting any nation’s economy. However, the industry is often criticised for not balancing economic, environmental and social dimensions of their projects, with emphasis typically on one aspect to the detriment of the others. This has resulted in many negative impacts including environmental pollution, waste throughout the project lifecycle, low productivity, and avoidable accidents. The identification of comprehensive Social Responsibility (SR) indicators, which combine social, environmental and economic aspects, is urgently needed. This is particularly the case in the context of the Kingdom of Saudi Arabia (KSA), which often has mega public construction projects. The aim of this paper is to develop a set of wide-ranging SR indicators which encompass social, economic and environmental aspects unique to the KSA. A qualitative approach was applied to explore relevant indicators through a review of the existing literature, international standards and reports. A list of appropriate indicators was developed, and its comprehensiveness was corroborated by interviews with experts on mega construction projects working with SR concepts in the KSA. The findings present 39 indicators and their metrics, covering 10 economic, 12 environmental and 17 social aspects of SR mapped against their references. These indicators are a valuable reference for decision-makers and academics in the KSA to understand factors related to SR in mega construction projects. The indicators are related to mega construction projects within the KSA and require validation in a real case scenario or within a different industry to demonstrate their generalisability.

Keywords: social responsibility, construction projects, economic, social, environmental, indicators

Procedia PDF Downloads 163
5180 The Relationship between Environmental Factors and Purchasing Decisions in the Residential Market in Sweden

Authors: Agnieszka Zalejska-Jonsson

Abstract:

The Swedish Green Building Council (SGBC) was established in 2009. Since then, over 1000 buildings have been certified, of which approximately 600 are newly produced and 340 are residential buildings. During that time, approximately 2000 apartment buildings have been built in Sweden. This means that over a five- year period 17% of residential buildings have been certified according to the environmental building scheme. The certification of the building is not a guarantee of environmental progress but it gives us an indication of the extent of the progress. The overarching aim of this study is to investigate the factors behind the relatively slow evolution of the green residential housing market in Sweden. The intention is to examine stated willingness to pay (WTP) for green and low energy apartments, and to explore which factors have a significant effect on stated WTP among apartment owners. A green building was defined as a building certified according to the environmental scheme and a low energy building as a building designed and constructed with high energy efficiency goals. Data for this study were collected through a survey conducted among occupants of comparable apartment buildings: two green and one conventional. The total number of received responses was 429: green A (N=160), response rate 42%; green B (N=138) response rate 35%, and conventional (N=131) response rate 43%. The study applied a quasi-experimental method. Survey responses regarding factors affecting purchase of apartment, stated WTP and environmental literacy have been analysed using descriptive statistics, the Mann–Whitney (rank sum) test and logistic models. Comments received from respondents have been used for further interpretation of results. Results indicate that environmental education has a significant effect on stated WTP. Occupants who declared higher WTP showed a higher level of environmental literacy and indicated that energy efficiency was one of the important factors that affected their decision to buy an apartment. Generally, the respondents were more likely to pay more for low energy buildings than for green buildings. This is to a great extent a consequence of rational customer behaviour and difficulty in apprehending the meaning of green building certification. The analysis shows that people living in green buildings indicate higher WTP for both green and low energy buildings, the difference being statistically significant. It is concluded that growth in the green housing market in Sweden might be achieved if policymakers and developers engage in active education in the environmental labelling system. The demand for green buildings is more likely to increase when the difference between green and conventional buildings is easily understood and information is not only delivered by the estate agent, but is part of an environmental education programme.

Keywords: consumer, environmental education, housing market, stated WTP, Sweden

Procedia PDF Downloads 237
5179 The Need for Implementing Building Information Modelling (BIM) and Integrated Project Delivery (IPD) in the Construction Project: A Case Study in UAE

Authors: C. W. F. Che Wan Putra, M. Alshawi, M. S. Al Ahbabi, M. Jabakhanji

Abstract:

Much of the waste that is generated throughout the life-cycle of a building is mainly related to project stakeholders not having access to information that others have created. This results in waste and high costs. Over the past decade, however, the industry reacted to these challenges by adopting effective procurement approaches, such as partnering and design and build, to improve collaboration and communication among projects’ stakeholders. Most recently, there is a focus on creating and reusing digital project information of stakeholders throughout the life-cycle to facilitate the exchange of information among partners. This shift is based around BIM (Building Information Modelling) and collaborative environment (IPD). The power of collaborative BIM goes beyond improving efficiency. Sustainability, perhaps the most important challenge for the design and construction community, is at the intersection of BIM and collaborative project delivery, drawing strength from both. Due to these benefits, a research study has been carried out to investigate the need of BIM and IPD, on a large scale construction project which is procured on a traditional approach, i.e. design-bid-build. A qualitative research work including a semi-structured interview with project partners was conducted on a typical project in the UAE, whereby the selected project suffered from severe delays and cost overrun. This paper aims to bring about clear evidence to what most likely to happen to a typical construction project in spite of employing very good consultants, project manager and contractors and how these problems could have been avoided if BIM and IPD were deployed.

Keywords: building information modelling (BIM), integrated project delivery (IPD), collaborative environment, case study

Procedia PDF Downloads 397
5178 Comparative Syudy Of Heat Transfer Capacity Limits of Heat Pipe

Authors: H. Shokouhmand, A. Ghanami

Abstract:

Heat pipe is simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At hot surface of heat pipe, the liquid phase absorbs heat and changes to vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to liquid phase. Due to gravitational force the liquid phase flows to evaporator section.In HVAC systems the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses heater, humidifier or dryer is a suitable nominate for the utilization of heat pipes. Generally heat pipes have three main sections: condenser, adiabatic region and evaporator.Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian- Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also observed that the vertical orientation of heat pipe enhances it’s heat transfer capacity.

Keywords: heat pipe, HVAC system, grooved heat pipe, heat pipe limits

Procedia PDF Downloads 366
5177 Intensive Use of Software in Teaching and Learning Calculus

Authors: Nodelman V.

Abstract:

Despite serious difficulties in the assimilation of the conceptual system of Calculus, software in the educational process is used only occasionally, and even then, mainly for illustration purposes. The following are a few reasons: The non-trivial nature of the studied material, Lack of skills in working with software, Fear of losing time working with software, The variety of the software itself, the corresponding interface, syntax, and the methods of working with the software, The need to find suitable models, and familiarize yourself with working with them, Incomplete compatibility of the found models with the content and teaching methods of the studied material. This paper proposes an active use of the developed non-commercial software VusuMatica, which allows removing these restrictions through Broad support for the studied mathematical material (and not only Calculus). As a result - no need to select the right software, Emphasizing the unity of mathematics, its intrasubject and interdisciplinary relations, User-friendly interface, Absence of special syntax in defining mathematical objects, Ease of building models of the studied material and manipulating them, Unlimited flexibility of models thanks to the ability to redefine objects, which allows exploring objects characteristics, and considering examples and counterexamples of the concepts under study. The construction of models is based on an original approach to the analysis of the structure of the studied concepts. Thanks to the ease of construction, students are able not only to use ready-made models but also to create them on their own and explore the material studied with their help. The presentation includes examples of using VusuMatica in studying the concepts of limit and continuity of a function, its derivative, and integral.

Keywords: counterexamples, limitations and requirements, software, teaching and learning calculus, user-friendly interface and syntax

Procedia PDF Downloads 77
5176 Heat Pipe Thermal Performance Improvement in H-VAC Systems Using CFD Modeling

Authors: H. Shokouhmand, A. Ghanami

Abstract:

Heat pipe is a simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At hot surface of the heat pipe, the liquid phase absorbs heat and changes to vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to liquid phase. Due to gravitational force, the liquid phase flows to evaporator section. In HVAC systems, the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses heater, humidifier or dryer is a suitable nominate for the utilization of heat pipes. Generally, heat pipes have three main sections: condenser, adiabatic region, and evaporator.Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In the present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of the heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian- Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also showed that the vertical orientation of heat pipe enhances its heat transfer capacity.

Keywords: heat pipe, HVAC system, grooved heat pipe, CFD simulation

Procedia PDF Downloads 491
5175 Characteristics of Pore Pressure and Effective Stress Changes in Sandstone Reservoir Due to Hydrocarbon Production

Authors: Kurniawan Adha, Wan Ismail Wan Yusoff, Luluan Almanna Lubis

Abstract:

Preventing hazardous events during oil and gas operation is an important contribution of accurate pore pressure data. The availability of pore pressure data also contribute in reducing the operation cost. Suggested methods in pore pressure estimation were mostly complex by the many assumptions and hypothesis used. Basic properties which may have significant impact on estimation model are somehow being neglected. To date, most of pore pressure determinations are estimated by data model analysis and rarely include laboratory analysis, stratigraphy study or core check measurement. Basically, this study developed a model that might be applied to investigate the changes of pore pressure and effective stress due to hydrocarbon production. In general, this paper focused velocity model effect of pore pressure and effective stress changes due to hydrocarbon production with illustrated by changes in saturation. The core samples from Miri field from Sarawak Malaysia ware used in this study, where the formation consists of sandstone reservoir. The study area is divided into sixteen (16) layers and encompassed six facies (A-F) from the outcrop that is used for stratigraphy sequence model. The experimental work was firstly involving data collection through field study and developing stratigraphy sequence model based on outcrop study. Porosity and permeability measurements were then performed after samples were cut into 1.5 inch diameter core samples. Next, velocity was analyzed using SONIC OYO and AutoLab 500. Three (3) scenarios of saturation were also conducted to exhibit the production history of the samples used. Results from this study show the alterations of velocity for different saturation with different actions of effective stress and pore pressure. It was observed that sample with water saturation has the highest velocity while dry sample has the lowest value. In comparison with oil to samples with oil saturation, water saturated sample still leads with the highest value since water has higher fluid density than oil. Furthermore, water saturated sample exhibits velocity derived parameters, such as poisson’s ratio and P-wave velocity over S-wave velocity (Vp/Vs) The result shows that pore pressure value ware reduced due to the decreasing of fluid content. The decreasing of pore pressure result may soften the elastic mineral frame and have tendency to possess high velocity. The alteration of pore pressure by the changes in fluid content or saturation resulted in alteration of velocity value that has proportionate trend with the effective stress.

Keywords: pore pressure, effective stress, production, miri formation

Procedia PDF Downloads 286
5174 Heat Pipes Thermal Performance Improvement in H-VAC Systems Using CFD Modeling

Authors: M. Heydari, A. Ghanami

Abstract:

Heat pipe is simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At hot surface of heat pipe, the liquid phase absorbs heat and changes to vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to liquid phase. Due to gravitational force the liquid phase flows to evaporator section.In HVAC systems the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses heater, humidifier or dryer is a suitable nominate for the utilization of heat pipes. Generally heat pipes have three main sections: condenser, adiabatic region and evaporator.Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian- Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also showed that the vertical orientation of heat pipe enhances it’s heat transfer capacity.

Keywords: heat pipe, HVAC system, grooved heat pipe, heat pipe limits

Procedia PDF Downloads 440
5173 Hybrid Temporal Correlation Based on Gaussian Mixture Model Framework for View Synthesis

Authors: Deng Zengming, Wang Mingjiang

Abstract:

As 3D video is explored as a hot research topic in the last few decades, free-viewpoint TV (FTV) is no doubt a promising field for its better visual experience and incomparable interactivity. View synthesis is obviously a crucial technology for FTV; it enables to render images in unlimited numbers of virtual viewpoints with the information from limited numbers of reference view. In this paper, a novel hybrid synthesis framework is proposed and blending priority is explored. In contrast to the commonly used View Synthesis Reference Software (VSRS), the presented synthesis process is driven in consideration of the temporal correlation of image sequences. The temporal correlations will be exploited to produce fine synthesis results even near the foreground boundaries. As for the blending priority, this scheme proposed that one of the two reference views is selected to be the main reference view based on the distance between the reference views and virtual view, another view is chosen as the auxiliary viewpoint, just assist to fill the hole pixel with the help of background information. Significant improvement of the proposed approach over the state-of –the-art pixel-based virtual view synthesis method is presented, the results of the experiments show that subjective gains can be observed, and objective PSNR average gains range from 0.5 to 1.3 dB, while SSIM average gains range from 0.01 to 0.05.

Keywords: fusion method, Gaussian mixture model, hybrid framework, view synthesis

Procedia PDF Downloads 245
5172 Carbon Fiber Manufacturing Conditions to Improve Interfacial Adhesion

Authors: Filip Stojcevski, Tim Hilditch, Luke Henderson

Abstract:

Although carbon fibre composites are becoming ever more prominent in the engineering industry, interfacial failure still remains one of the most common limitations to material performance. Carbon fiber surface treatments have played a major role in advancing composite properties however research into the influence of manufacturing variables on a fiber manufacturing line is lacking. This project investigates the impact of altering carbon fiber manufacturing conditions on a production line (specifically electrochemical oxidization and sizing variables) to assess fiber-matrix adhesion. Pristine virgin fibers were manufactured and interfacial adhesion systematically assessed from a microscale (single fiber) to a mesoscale (12k tow), and ultimately a macroscale (laminate). Correlations between interfacial shear strength (IFSS) at each level is explored as a function of known interfacial bonding mechanisms; namely mechanical interlocking, chemical adhesion and fiber wetting. Impact of these bonding mechanisms is assessed through extensive mechanical, topological and chemical characterisation. They are correlated to performance as a function of IFSS. Ultimately this study provides a bottoms up approach to improving composite laminates. By understanding the scaling effects from a singular fiber to a composite laminate and linking this knowledge to specific bonding mechanisms, material scientists can make an informed decision on the manufacturing conditions most beneficial for interfacial adhesion.

Keywords: carbon fibers, interfacial adhesion, surface treatment, sizing

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5171 Bridging the Gap and Widening the Divide

Authors: Lerato Dixon, Thorsten Chmura

Abstract:

This paper explores whether ethnic identity in Zimbabwe leads to discriminatory behaviour and the degree to which a norm-based intervention can shift this discriminatory behaviour. Social Identity Theory suggests that group identity can lead to favouritism towards the in-group and discriminatory behaviour towards the out-group. Agents yield higher utility from maintaining positive self-esteem by confirming with group behaviour. This paper focuses on the two majority ethnic groups in Zimbabwe – the Ndebele and Shona. Racial identities are synonymous with the language spoken. Zimbabwe’s history highlights how identity formation took place. As following independence, political parties became recognised as either Ndebele or Shona-speaking. It is against this backdrop that this study investigates the degree to which norm-based nudge can alter behaviour. This paper uses experimental methods to analyse discriminatory behaviour between two naturally occurring ethnic groups in Zimbabwe. In addition, we investigate if social norm-based interventions can shift discriminatory behaviour to understand if the divide between these two identity groups can be further divided or healed. Participants are randomly assigned into three groups to receive information regarding a social norm. We compare the effect of a proscriptive social norm-based intervention, stating what shouldn't be done and prescriptive social norms as interventions, stating what should be done. Specifically, participants are either shown the socially appropriate (Heal) norm, the socially inappropriateness (Divide) norm regarding interethnic marriages or no norm-based intervention. Following the random assignment into intervention groups, participants take part in the Trust Game. We conjecture that discrimination will shift in accordance with the prevailing social norm. Instead, we find evidence of interethnic discriminatory behaviour. We also find that trust increases when interacting with Ndebele, Shona and Zimbabwean participants following the Heal intervention. However, if the participant is Shona, the Heal intervention decreases trust toward in-groups and Zimbabwean co-players. On the other hand, if the participant is Shona, the Divide treatment significantly increases trust toward Ndebele participants. In summary, we find evidence that norm-based interventions significantly change behaviour. However, the prescriptive norm-based intervention (Heal) decreases trust toward the in-group, out-group and national identity group if the participant is Shona – therefore having an adverse effect. In contrast, the proscriptive Divide treatment increases trust if the participant is Shona towards Ndebele co-players. We conclude that norm-based interventions have a ‘rebound’ effect by altering behaviour in the opposite direction.

Keywords: discrimination, social identity, social norm-based intervention, zimbabwe

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5170 Choice Experiment Approach on Evaluation of Non-Market Farming System Outputs: First Results from Lithuanian Case Study

Authors: A. Novikova, L. Rocchi, G. Startiene

Abstract:

Market and non-market outputs are produced jointly in agriculture. Their supply depends on the intensity and type of production. The role of agriculture as an economic activity and its effects are important for the Lithuanian case study, as agricultural land covers more than a half of country. Positive and negative externalities, created in agriculture are not considered in the market. Therefore, specific techniques such as stated preferences methods, in particular choice experiments (CE) are used for evaluation of non-market outputs in agriculture. The main aim of this paper is to present construction of the research path for evaluation of non-market farming system outputs in Lithuania. The conventional and organic farming, covering crops (including both cereal and industrial crops) and livestock (including dairy and cattle) production has been selected. The CE method and nested logit (NL) model were selected as appropriate for evaluation of non-market outputs of different farming systems in Lithuania. A pilot survey was implemented between October–November 2018, in order to test and improve the CE questionnaire. The results of the survey showed that the questionnaire is accepted and well understood by the respondents. The econometric modelling showed that the selected NL model could be used for the main survey. The understanding of the differences between organic and conventional farming by residents was identified. It was revealed that they are more willing to choose organic farming in comparison to conventional farming.

Keywords: choice experiments, farming system, Lithuania market outputs, non-market outputs

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5169 Evaluating Closed-List Proportional Representation System and Its Compatibility in Contemporary Indonesian Election

Authors: Ridho Al-Hamdi, Sakir, Tanto Lailam

Abstract:

During the democratic period of 1999-present, Indonesia has consistently applied a List Proportional Representation (List PR) system in the parliamentary election. Between 1999 and 2004, it adopted a closed-list proportional representation (CLPR) system. In the meantime, it employed open-list proportional representation (OLPR) system from 2009 to 2019. Recently, some parties intended to propose the application of CLPR while others are still consistent in adopting OLPR. An unfinished debate is taking place. Thus, this article aims to evaluate the application of CLPR in Indonesia and, in turn, analyze its compatibility in contemporary parliamentary election system. From a methodological standpoint, it is qualitative research by applying a case study approach. Data-gathering relies on field data, mainly focus group discussion (FGD) and in-depth interviews with political parties, electoral management bodies (EMBs), NGO activists, and scholars spread in six provinces and nine regencies/cities across the country. Using SWOT analysis and the compatibility of CLPR and embedded democracy framework, the finding demonstrates that CLPR is no longer relevant for contemporary Indonesian elections. This paper recommends OLPR by considering that CLPR has numerous weaknesses and threats that can jeopardize embedded democracy. More importantly, CLPR can remove inclusive suffrage significantly.

Keywords: closed-list proportional representation, embedded democracy, Indonesia, parliamentary election

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5168 Navigating Urban Childcare Challenges: Perspectives of Dhaka City Parents

Authors: Md. Shafiullah

Abstract:

This study delves into the evolving landscape of urban childcare in Bangladesh, focusing on the experiences and challenges faced by parents in Dhaka city. This paper argues that the traditional childcare arrangement of city families is inadequate to meet the development needs of children. The study aims to explore the childcare challenges faced by urban parents as they transition from traditional family-based childcare networks to alternative caregiving arrangements amidst urbanization, economic shifts, and social transformations. Utilizing a mixed-method research approach, combining quantitative surveys (n = 200) and four qualitative interviews, the research examines the parental viewpoints on childcare practices and the role of societal norms and values. The study finds childcare crises in both the family and daycare settings. In family care, caregiving suffers from the less availability of grandparents, a lack of skills of caregivers, and a lack of child interaction. As for the daycare, it is affected by the absence of appropriate policies, a lack of quality, health and safety concerns, affordability issues, and cultural concerns. Additionally, the study highlights inadequacies in childcare policies and regulatory frameworks, calling for comprehensive reforms to address the childcare vacuum in urban areas. By shifting the focus from developed to developing countries, this study contributes to the literature and suggests policy implications for Bangladesh and beyond.

Keywords: childcare, child development, childcare policy, daycare, Bangladesh

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5167 The Semiotic Analysis of Thai Social Contexts in Thai Post’s News Articles

Authors: Pakpoom Hannapha

Abstract:

This paper investigates the implications of social and political contexts in Thai Post’s news articles written by a columnist, Khon Plai Soy. Samples included twenty eight news articles published between 28th May 2015 and 28th June 2015 selected and analyzed according to Semiotics including implications, connotation, cultural politics, and Thai usage in newspaper articles. The data analysis can be divided into two parts; first, an analysis of signs/signifiers appearing in the articles and second, an analysis of the columnist’s purposes. This study demonstrated representations of signs in the selected articles that were categorized into four groups: events, actions, persons, and organizations. In this study, implications of the news articles were analyzed in two aspects according to Semiotics. It was found that the columnist mostly points out purposes for education, facts, and personal opinions in his works. Also, he offers some solutions to problems discussed in the articles. The writer often explicated knowledge and facts in accordance with either his personal opinions or problem-solutions. According to the research result, studying the implications of news articles in the Thai Post based on the Semiotic approach can help clarify and understand connotative meanings in terms of contents and the writer’s purposes. This paper can enhance readers’ understanding of Semiotic implications through signs and meanings in the texts and thus be used as a model to explore other political news articles

Keywords: semiotic analysis, Thai social contexts, Thai Post’s news, articles

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5166 Hybrid Wind Solar Gas Reliability Optimization Using Harmony Search under Performance and Budget Constraints

Authors: Meziane Rachid, Boufala Seddik, Hamzi Amar, Amara Mohamed

Abstract:

Today’s energy industry seeks maximum benefit with maximum reliability. In order to achieve this goal, design engineers depend on reliability optimization techniques. This work uses a harmony search algorithm (HS) meta-heuristic optimization method to solve the problem of wind-Solar-Gas power systems design optimization. We consider the case where redundant electrical components are chosen to achieve a desirable level of reliability. The electrical power components of the system are characterized by their cost, capacity and reliability. The reliability is considered in this work as the ability to satisfy the consumer demand which is represented as a piecewise cumulative load curve. This definition of the reliability index is widely used for power systems. The proposed meta-heuristic seeks for the optimal design of series-parallel power systems in which a multiple choice of wind generators, transformers and lines are allowed from a list of product available in the market. Our approach has the advantage to allow electrical power components with different parameters to be allocated in electrical power systems. To allow fast reliability estimation, a universal moment generating function (UMGF) method is applied. A computer program has been developed to implement the UMGF and the HS algorithm. An illustrative example is presented.

Keywords: reliability optimization, harmony search optimization (HSA), universal generating function (UMGF)

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5165 Managerial Leadership Styles of Deans in Indonesian Universities

Authors: Jenny Ngo, Harry De Boer, Jurgen Enders

Abstract:

Indonesian higher education has experienced significant changes over the last decade. In 1999, the government published an overall strategy for decentralization and enhancement of local autonomy in many sectors, including (higher) education. Indonesian higher education reforms have forced universities to restructure their internal university governance to become more entrepreneurial. These new types of internal university governance are likely to affect the institutions’ leadership and management. This paper discusses the approach and findings of a study on the managerial leadership styles of deans in Indonesian universities. The study aims to get a better understanding of styles exhibited by deans manifested in their behaviors. Using the theories of reasoned action and planned behavior, in combination with the competing values framework, a large-scale survey was conducted to gather information on the deans’ behaviors, attitudes, subjective norms, and perceived behavioral control. Based on the responses of a sample of 218 deans, the study identifies a number of leadership styles: the Master, the Competitive Consultant, the Consensual Goal-Setter, the Focused Team Captain, and the Informed Trust-Builder style. The study demonstrates that attitudes are the primary determinant of the styles that were found. Perceived behavioral control is a factor that explains some managerial leadership styles. By understanding the attitudes of deans in Indonesian universities, and their leadership styles, universities can strengthen their management and governance, and thus improve their effectiveness.

Keywords: deans, Indonesian higher education, leadership and management styles, decentralization

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5164 The Importance of Zenithal Lighting Systems for Natural Light Gains and for Local Energy Generation in Brazil

Authors: Ana Paula Esteves, Diego S. Caetano, Louise L. B. Lomardo

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This paper presents an approach on the advantages of using adequate coverage in the zenithal lighting typology in various areas of architectural production, while at the same time to encourage to the design concerns inherent in this choice of roofing in Brazil. Understanding that sustainability needs to cover several aspects, a roofing system such as zenithal lighting system can contribute to the provision of better quality natural light for the interior of the building, which is related to the good health and welfare; it will also be able to contribute for the sustainable aspects and environmental needs, when it allows the generation of energy in semitransparent or opacity photovoltaic solutions and economize the artificial lightning. When the energy balance in the building is positive, that is, when the building generates more energy than it consumes, it may fit into the Net Zero Energy Building concept. The zenithal lighting systems could be an important ally in Brazil, when solved the burden of heat gains, participate in the set of pro-efficiency actions in search of "zero energy buildings". The paper presents comparative three cases of buildings that have used this feature in search of better environmental performance, both in light comfort and sustainability as a whole. Two of these buildings are examples in Europe: the Notley Green School in the UK and the Isofóton factory in Spain. The third building with these principles of shed´s roof is located in Brazil: the Ipel´s factory in São Paulo.

Keywords: natural lighting, net zero energy building, sheds, semi-transparent photovoltaics

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5163 Physics Recitations for College Physics Courses Using Breakout Rooms during COVID Pandemic

Authors: Pratheesh Jakkala

Abstract:

This paper addresses the use of breakout sessions to conduct successful weekly physics recitations for College Physics I and II at a large University in remote teaching method during COVID-19 pandemic. All breakout sessions are synchronous, conducted live, and handled by teaching assistants. A two-prong approach is used to maintain the integrity of recitations. Three different conference platforms WebEx, Zoom, and Canvas conferences, were tested, and BigBlue button using Canvas was adopted. The results and experiences of all three learning platforms are presented in this paper. Recitation questions were assigned on WebAssign learning platform and a standard five-question template developed by the instructor was used for group discussions and active peer-peer engagement. Breakout sessions feature of BigBlueButton in Canvas conferences was successfully implemented. Each breakout session consists of a team of 4 students. An online whiteboard, chat window options were used for live teamwork. Student peer-peer interactions, Teaching Assistants’ interaction with students were video and audio recorded. A total of 72 students in College Physics II and 55 students in College Physics I was enrolled. 82% of students agreed that method under study is better than previous methods. The study addressed the quality of student teamwork, student attitude towards problem-solving, and student performance in the exams.

Keywords: recitations, breakout rooms, online learning platforms, COVID pandemic

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5162 Waste Prevention and Economic Policy: Policy Tools for Increasing Resource Efficiency and Savings

Authors: Sylvia Graczka

Abstract:

Waste related environmental problems are not only exploding but are also spotlighted for capacity shortages in recycling, as China announced its ban on waste imports. According to the waste hierarchy, prevention is the primary solution for waste, and also the cheapest. Waste related environmental pollution as externality puts an ever-growing burden on communities bearing the social costs. Economic policies often claim to be pro-environment, this often appears only theoretically, or at the level of principles. There are few concrete occurrences of tools in economic policies, such as green taxes, that are truly effective in stimulating the shift towards waste reduction. The paper presents theoretical economic policy tools based on literature review, and case studies on applied economic policy tools by analyzing policy papers, strategies in force, in line with ‘polluter pays’ and ‘extended producer responsibility’ principles. The study also emphasizes the differences between the broader notion of waste reduction and that of waste minimization, parallel to the difference between resource efficiency and resource savings. It also puts the issue in the context of neoclassical environmental economics and ecological economics, to present alternatives in approach. The research concludes in identifying effective economic policy tools that support the reduction of material use, and the prevention of waste. Consumer and producer awareness of waste problems and consciousness related to their choices are inevitable to make economic policy tools work effectively.

Keywords: economic policy, producer responsibility, resource efficiency, waste prevention

Procedia PDF Downloads 140