Search results for: natural numbers
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 6891

Search results for: natural numbers

4311 Comparison of Modulus from Repeated Plate Load Test and Resonant Column Test for Compaction Control of Trackbed Foundation

Authors: JinWoog Lee, SeongHyeok Lee, ChanYong Choi, Yujin Lim, Hojin Cho

Abstract:

Primary function of the trackbed in a conventional railway track system is to decrease the stresses in the subgrade to be in an acceptable level. A properly designed trackbed layer performs this task adequately. Many design procedures have used assumed and/or are based on critical stiffness values of the layers obtained mostly in the field to calculate an appropriate thickness of the sublayers of the trackbed foundation. However, those stiffness values do not consider strain levels clearly and precisely in the layers. This study proposes a method of computation of stiffness that can handle with strain level in the layers of the trackbed foundation in order to provide properly selected design values of the stiffness of the layers. The shear modulus values are dependent on shear strain level so that the strain levels generated in the subgrade in the trackbed under wheel loading and below plate of Repeated Plate Bearing Test (RPBT) are investigated by finite element analysis program ABAQUS and PLAXIS programs. The strain levels generated in the subgrade from RPBT are compared to those values from RC (Resonant Column) test after some consideration of strain levels and stress consideration. For comparison of shear modulus G obtained from RC test and stiffness moduli Ev2 obtained from RPBT in the field, many numbers of mid-size RC tests in laboratory and RPBT in field were performed extensively. It was found in this study that there is a big difference in stiffness modulus when the converted Ev2 values were compared to those values of RC test. It is verified in this study that it is necessary to use precise and increased loading steps to construct nonlinear curves from RPBT in order to get correct Ev2 values in proper strain levels.

Keywords: modulus, plate load test, resonant column test, trackbed foundation

Procedia PDF Downloads 495
4310 Antimicrobial Activity of Oil Extracted from the Almonds of the Fruits of Argania spinosa in the West of Algeria (Mostaganem)

Authors: Nassima Behidj-Benyounes, Nadjiba Chebouti, Thoraya Dahmane, Amina Henni

Abstract:

This work examines the study of the antimicrobrial effect of oil extracted from the seeds of Argania spinosa L. (Sapotaceae) in the area of Stida (Mostaganem). This natural substance is extracted by using the Soxhlet. The antimicrobial activity of this oil is evaluated on several microorganisms. It has been tested on five bacterial strains; Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Bacillus subtilis and Staphylococcus aureus. The extract has been studied by using Candida albicans. It should be noted that these agents are characterized by a high frequency of contamination and pathogenicity. Through this study, we note that these microorganisms are moderately sensitive to the argan oil.

Keywords: Argania spinosa, oil, several microorganisms, almonds, antimicrobial activity

Procedia PDF Downloads 416
4309 Loss Analysis by Loading Conditions of Distribution Transformers

Authors: A. Bozkurt, C. Kocatepe, R. Yumurtaci, İ. C. Tastan, G. Tulun

Abstract:

Efficient use of energy, with the increase in demand of energy and also with the reduction of natural energy sources, has improved its importance in recent years. Most of the losses in the system from electricity produced until the point of consumption is mostly composed by the energy distribution system. In this study, analysis of the resulting loss in power distribution transformer and distribution power cable is realized which are most of the losses in the distribution system. Transformer losses in the real distribution system were analyzed by CYME Power Engineering Software program. These losses are disclosed for different voltage levels and different loading conditions.

Keywords: distribution system, distribution transformer, power cable, technical losses

Procedia PDF Downloads 652
4308 Adsorption Behavior and Mechanism of Illite Surface under the Action of Different Surfactants

Authors: Xiuxia Sun, Yan Jin, Zilong Liu, Shiming Wei

Abstract:

As a critical mineral component of shale, illite is essential in oil exploration and development due to its surface hydration characteristics and action mechanism. This paper, starting from the perspective of the molecular structure of organic matter, uses molecular dynamics simulation technology to deeply explore the interaction mechanism between organic molecules and the illite surface. In the study, we thoroughly considered the forces such as van der Waals force, electrostatic force, and steric hindrance and constructed an illite crystal model covering C8-C18 modifiers. Subsequently, we systematically analyzed surfactants' adsorption behavior and hydration characteristics with different alkyl chain numbers, lengths, and concentrations on the illite surface. The simulation results show that surfactant molecules with shorter alkyl chains present a lateral monolayer or inclined double-layer arrangement on the illite surface, and these two arrangements may coexist under different concentration conditions. In addition, with the increase in the number of alkyl chains, the interlayer spacing of illite increases significantly. In contrast, the change in alkyl chain length has a limited effect on surface properties. It is worth noting that the change in functional group structure has a particularly significant effect on the wettability of the illite surface, and its influence even exceeds the change in the alkyl chain structure. This discovery gives us a new perspective on understanding and regulating the wetting properties. The results obtained are consistent with the XRD analysis and wettability experimental data in this paper, further confirming the reliability of the research conclusions. This study deepened our understanding of illite's hydration characteristics and mechanism. We provided new ideas and directions for the molecular design and application development of oilfield chemicals.

Keywords: illite, surfactant, hydration, wettability, adsorption

Procedia PDF Downloads 43
4307 An Alternative to Resolve Land use Conflicts: the Rétköz Lake Project

Authors: Balázs Kulcsár

Abstract:

Today, there is no part of the world that does not bear the mark of man in some way. This process seems unstoppable. So perhaps the best thing we can do is to touch that handprint gently and with the utmost care. There are multiple uses for the same piece of land, the coordination of which requires careful and sustainable spatial planning. The case study of the Rétközlake in north-eastern Hungary illustrates a habitat rehabilitation project in which a number of human uses were coordinated with the conservation and restoration of the natural environment. Today, the good condition of the habitat can only be maintained artificially, but the project has paid particular attention to finding a sustainable solution. The rehabilitation of Lake Rétköz is considered good practice in resolving land-use conflicts.

Keywords: sustainability, ecosystem service, land use conflict, landscape utilization

Procedia PDF Downloads 168
4306 Yield, Economics and ICBR of Different IPM Modules in Bt Cotton in Maharashtra

Authors: N. K. Bhute, B. B. Bhosle, D. G. More, B. V. Bhede

Abstract:

The field experiments were conducted during kharif season of the year 2007-08 at the experimental farm of the Department of Agricultural Entomology, Vasantrao Naik Marathwada Krishi Vidyapeeth, Studies on evaluation of different IPM modules for Bt cotton in relation to yield economics and ICBR revealed that MAU and CICR IPM modules proved superior. It was, however, on par with chemical control. Considering the ICBR and safety to natural enemies, an inference can be drawn that Bt cotton with IPM module is the most ideal combination. Besides reduction in insecticide use, it is also expected to ensure favourable ecological and economic returns in contrast to the adverse effects due to conventional insecticides. The IPM approach, which takes care of varying pest situation, appears to be essential for gaining higher advantage from Bt cotton.

Keywords: yield, economics, ICBR, IPM Modules, Bt cotton

Procedia PDF Downloads 268
4305 Homelessness and Disaster Mitigation: An Exploratory Study into How Casualties Can Be Reduced with the Homeless

Authors: Blythe Maltby

Abstract:

Homeless populations are one of the sections of society most vulnerable to the effects of natural disasters. Channels of communication to these populations are limited as they lack access to mainstream modes of emergency notification, often being the last to know about state emergencies. This study aims to answer if there is a way that cities and policies be designed to help reduce casualty rates to the homeless during state emergencies, such as earthquake and tsunami preparations. The study used a qualitative research approach, namely by speaking to levels of government, homelessness charities and workers and others about preparations and their experiences with the response of state emergencies. The proposed paper may help countries identify the gaps in their preparations to help facilitate better resources to look after these vulnerable populations.

Keywords: accessibility, disaster mitigation, homeless, Vancouver

Procedia PDF Downloads 223
4304 Investigation of the Kutta Condition Using Unsteady Flow

Authors: K. Bhojnadh, M. Fiddler, D. Cheshire

Abstract:

An investigation into the Kutta effect on the trailing edge of a subsonic aerofoil was conducted which led to an analysis using Ansys Fluent to determine the effect of flow separation over a NACA 0012 aerofoil. This aerofoil was subjected to oscillations to create an unsteady flow over the aerofoil, therefore, creating turbulence, with unsteady aerodynamics playing a key role to determine the flow regimes when the aerofoil is subjected to different angles of attack along with varying Reynolds numbers. Many theories were evolved to determine the flow parameters of a 2-D aerofoil in these unsteady conditions because they behave unpredictably at the trailing edge when subjected to a different angle of attack. The shear area observed in the boundary layer at the trailing edge tends towards an unsteady turbulent flow even at small angles of attack, creating drag as the flow separates, reducing the aerodynamic performance of aerofoil. In this paper, research was conducted to determine the effect of Kutta circulation over the aerofoil and the effect of that circulation in reducing the effect of pressure and boundary layer distribution over the aerofoil. The effect of circulation is observed by using Ansys Fluent by using varying flow parameters and differential schemes to observe the flow behaviour on the aerofoil. Initially, steady flow analysis was conducted on the aerofoil to determine the effect of circulation, and it was noticed that the effect of circulation could only be properly observed when the aerofoil is subjected to oscillations. Therefore, that was modelled by using Ansys user-defined functions, which define the motion of the aerofoil by creating a dynamic mesh on the aerofoil. Initial results were observed, and further development of the dynamic mesh functions in Ansys is taking place. This research will determine the overall basic principles of unsteady flow aerodynamics applied to the investigation of Kutta related circulation, and gives an indication regarding the generation of vortices which is discussed further in this paper.

Keywords: circulation, flow seperation, turbulence modelling, vortices

Procedia PDF Downloads 205
4303 WASH Governance Opportunity for Inspiring Innovation and a Circular Economy in Karnali Province of Nepal

Authors: Nirajan Shrestha

Abstract:

Karnali is one of the most vulnerable provinces in Nepal, facing challenges from climate change, poverty, and natural calamities across different regions. In recent years, the province has been severely impacted by climate change stress such as temperature rises in glacier lake of mountainous region and spring source water shortages, particularly in hilly areas where settlements are located, and water sources have depleted from their original ground levels. As a result, Karnali could face a future without enough water for all. Deep causes of sustainable safe water supply have always been neglected in rural areas of Nepal, and communities are unfairly burdened with a challenge of keeping water facilities functioning in areas affected by frequent natural disasters where there is a substantial, well-documented funding gap between the revenues from user payments and the full cost of sustained services. The key importance of a permanent system to support communities in service delivery has been always underrated so far. The complexity of water service sustainability as a topic should be simplified to one clear indicator: the functionality rate, which can be expressed as uptime or the percentage of time that the service is delivered over the total time. For example, a functionality rate of 80% means that the water service is operational 80% of the time, while 20% of the time the system is not functioning. This represents 0.2 multiplied by 365, which equals 73 days every year, or roughly two and a half months without water. This percentage should be widely understood and used in Karnali. All local governments should report their targets and performance in improving it, and there should be a broader discussion about what target is acceptable and what can be realistically achieved. In response to these challenges, the Sustainable WASH for All (SUSWA) project has introduced innovative models and policy formulation strategies in various working local government. SUSWA’s approach, which delegates rural water supply and sanitation responsibilities to local governments, has been instrumental in addressing these issues. To keep pace with the growing demand, the province has adopted a service support center model, linking local governments with federal authorities to ensure effective service delivery to the communities By enhancing WASH governance through local governments engagement, capacity building and inclusive WASH policy frameworks, there is potential to address WASH gaps while fostering a circular economy. This strategy emphasizes resource recovery, waste minimization and the creation of local employment generation opportunities. The research highlights key governance mechanisms, innovative practices and policy interventions that can be scaled up across other regions. It also provides recommendations on how to leverage Karnali’s unique socio-economic and environmental context nature-based solutions to inspire innovation and drive sustainable WASH solutions. Key findings suggest that with strong ownership and leadership of local governments, community engagement and appropriate technology, Karnali Province can become a model for integrating WASH governance with circular economy concept, providing broader lessons for other regions in Nepal.

Keywords: vulnerable provinces, natural calamities, climate change stres, spring source depletion, resources recovery, governance mechanisms, appropriate technology, community engagement, innovation

Procedia PDF Downloads 14
4302 Origins of the Tattoo: Decoding the Ancient Meanings of Terrestrial Body Art to Establish a Connection between the Natural World and Humans Today

Authors: Sangeet Anand

Abstract:

Body art and tattooing have long been practiced as a form of self-expression for centuries, and this study studies and analyzes the pertinence of tattoo culture in our everyday lives and ancient past. Individuals of different cultures represent ideas, practices, and elements of their cultures through symbolic representation. These symbols come in all shapes and sizes and can be as simple as the makeup you put on every day to something more permanent such as a tattoo. In the long run, these individuals who choose to display art on their bodies are seeking to express their individuality. In addition, these visuals are ultimately a reflection of our own appropriate cultures deem as beautiful, important, and powerful to the human eye. They make us known to the world and give us a plausible identity in an ever-changing world. We have lived through and seen a rise in hippie culture today. This type of bodily decoration displayed by this fad has made it seem as though body art is a visual language that is relatively new. But quite to the contrary, it is not. Through cultural symbolic exploration, we can answer key questions to ideas that have been raised for centuries. Through careful, in-depth interviews, this study takes a broad subject matter-art, and symbolism-and culminates it into a deeper philosophical connection between the world and its past. The basic methodologies used in this sociocultural study include interview questionnaires and textual analysis, which encompass a subject and interviewer as well as source material. The major findings of this study contain a distinct connection between cultural heritage and the day-to-day likings of an individual. The participant that was studied during this project demonstrated a clear passion for hobbies that were practiced even by her ancestors. We can conclude, through these findings, that there is a deeper cultural connection between modern day humans, the first humans, and the surrounding environments. Our symbols today are a direct reflection of the elements of nature that our human ancestors were exposed to, and, through cultural acceptance, we can adorn ourselves with these representations to help others identify our pasts. Body art embraces the different aspects of different cultures and holds significance, tells stories, and persists, even as the human population rapidly integrates. With this pattern, our human descendents will continue to represent their cultures and identities in the future. Body art is an integral element in understanding how and why people identify with certain aspects of life over others and broaden the scope for conducting more analysis cross-culturally.

Keywords: natural, symbolism, tattoo, terrestrial

Procedia PDF Downloads 107
4301 Biophilic Design Strategies: Four Case-Studies from Northern Europe

Authors: Carmen García Sánchez

Abstract:

The UN's 17 Sustainable Development Goals – specifically the nº 3 and nº 11- urgently call for new architectural design solutions at different design scales to increase human contact with nature in the health and wellbeing promotion of primarily urban communities. The discipline of Interior Design offers an important alternative to large-scale nature-inclusive actions which are not always possible due to space limitations. These circumstances provide an immense opportunity to integrate biophilic design, a complex emerging and under-developed approach that pursues sustainable design strategies for increasing the human-nature connection through the experience of the built environment. Biophilic design explores the diverse ways humans are inherently inclined to affiliate with nature, attach meaning to and derive benefit from the natural world. It represents a biological understanding of architecture which categorization is still in progress. The internationally renowned Danish domestic architecture built in the 1950´s and early 1960´s - a golden age of Danish modern architecture - left a leading legacy that has greatly influenced the domestic sphere and has further led the world in terms of good design and welfare. This study examines how four existing post-war domestic buildings establish a dialogue with nature and her variations over time. The case-studies unveil both memorable and unique biophilic resources through sophisticated and original design expressions, where transformative processes connect the users to the natural setting and reflect fundamental ways in which they attach meaning to the place. In addition, fascinating analogies in terms of this nature interaction with particular traditional Japanese architecture inform the research. They embody prevailing lessons for our time today. The research methodology is based on a thorough literature review combined with a phenomenological analysis into how these case-studies contribute to the connection between humans and nature, after conducting fieldwork throughout varying seasons to document understanding in nature transformations multi-sensory perception (via sight, touch, sound, smell, time and movement) as a core research strategy. The cases´ most outstanding features have been studied attending the following key parameters: 1. Space: 1.1. Relationships (itineraries); 1.2. Measures/scale; 2. Context: Context: Landscape reading in different weather/seasonal conditions; 3. Tectonic: 3.1. Constructive joints, elements assembly; 3.2. Structural order; 4. Materiality: 4.1. Finishes, 4.2. Colors; 4.3. Tactile qualities; 5. Daylight interplay. Departing from an artistic-scientific exploration this groundbreaking study provides sustainable practical design strategies, perspectives, and inspiration to boost humans´ contact with nature through the experience of the interior built environment. Some strategies are associated with access to outdoor space or require ample space, while others can thrive in a dense urban context without direct access to the natural environment. The objective is not only to produce knowledge, but to phase in biophilic design in the built environment, expanding its theory and practice into a new dimension. Its long-term vision is to efficiently enhance the health and well-being of urban communities through daily interaction with Nature.

Keywords: sustainability, biophilic design, architectural design, interior design, nature, Danish architecture, Japanese architecture

Procedia PDF Downloads 100
4300 The Influence of Green Supply Chain Management Practices' Implementation on Organizational Performance: An Empirical Case Study in Spain

Authors: Keivan Amirbagheri, Ana Nuñez-Carballosa, Laura Guitart-Tarrés

Abstract:

Over the last couple of decades, enterprises have begun to accept the need for environmental management and have started to implement environmental management programs to compete in the markets. The implementation of green supply chain management (GSCM) practices can provide valuable opportunities to improve firm performance. Through the prior investigations, the ascending tendency of the numbers of published papers in the field of green supply chain management practices has been reported and it shows the high interest level of the authors to work in this area. Besides, there is still a gap to study more about the relationship of GSCM to the organizational performance (OP). So, the purpose of this research is to study the practices related to green supply chain management that influence the results of the company as an organizational performance. Based on our previous works, from one part we have collected these GSCM practices (planning, operational, and communication practices) and classified them through conducting some literature reviews to analyze their effects on the OP’s factors (balanced scorecard’s perspectives). To do so we design a case study methodology through semi-structured interviews and secondary data from some multinational well-known companies based in Spain. The cases have been selected with the criterion of trying to collect members of the entire supply chain to have a vision as global as possible. The results report the considerable influence of green supply chain management practices on the organizational performance of the companies of the study. In addition, they represent that the implementation of green supply chain management practices especially in a long-term perspective can be economically justified. From the point of view of the personal, they feel better about being a member of this type of company that has been structured on environmental issues. Also, for these companies, the image that has been created by the implementation of these practices helps them to facilitate their marketing program.

Keywords: green supply chain management, organizational performance, case study, Spain

Procedia PDF Downloads 190
4299 Shifting to Electronic Operative Notes in Plastic surgery

Authors: Samar Mousa, Galini Mavromatidou, Rebecca Shirley

Abstract:

Surgeons carry out numerous operations in the busy burns and plastic surgery department daily. Writing an accurate operation note with all the essential information is crucial for communication not only within the plastics team but also to the multi-disciplinary team looking after the patient, including other specialties, nurses and GPs. The Royal college of surgeons of England, in its guidelines of good surgical practice, mentioned that the surgeon should ensure that there are clear (preferably typed) operative notes for every procedure. The notes should accompany the patient into recovery and to the ward and should give sufficient detail to enable continuity of care by another doctor. The notes should include the Date and time, Elective/emergency procedure, Names of the operating surgeon and assistant, Name of the theatre anesthetist, Operative procedure carried out, Incision, Operative diagnosis, Operative findings, Any problems/complications, Any extra procedure performed and the reason why it was performed, Details of tissue removed, added or altered, Identification of any prosthesis used, including the serial numbers of prostheses and other implanted materials, Details of closure technique, Anticipated blood loss, Antibiotic prophylaxis (where applicable), DVT prophylaxis (where applicable), Detailed postoperative care instructions and Signature. Fourteen random days were chosen in December 2021 to assess the accuracy of operative notes and post-operative care. A total of 163 operative notes were examined. The average completion rates in all domains were 85.4%. An electronic operative note template was designed to cover all domains mentioned in the Royal College of surgeons' good surgical practice. It is kept in the hospital drive for all surgeons to use.

Keywords: operative notes, plastic surgery, documentation, electronic

Procedia PDF Downloads 79
4298 Utilization Of Medical Plants Tetrastigma glabratum (Blume) Planch from Mount Prau in the Blumah, Central Java

Authors: A. Lianah, B. Peter Sopade, C. Krisantini

Abstract:

Walikadep/Tetrastigma glabratum (Blume) Planch is a traditional herb that has been used by people of Blumah village; it is believed to have a stimulant effect and ailments for many illnesses. Our survey demonstrated that the people of Blumah village has exploited walikadep from Protected Forest of Mount Prau. More than 10% of 448 households at Blumah village have used walikadep as traditional herb or jamu. Part of the walikadep plants used is the liquid extract of the stem. The population of walikadep is getting scarce and it is rarely found now. The objectives of this study are to examine the stimulant effect of walikadep, to measure growth and exploitation rate of walikadep, and to find ways to effectively propagate the plants, as well as identifying the impact on the environment through field experiments and explorative survey. Stimulant effect was tested using open-field and hole-board test. Data were collected through field observation and experiment, and data were analysed using lab test and Anova. Rate of exploitation and plant growth was measured using Regression analysis; comparison of plant growth in-situ and ex-situ used descriptive analysis. The environmental impact was measured by population structure vegetation analysis method by Shannon Weinner. The study revealed that the walikadep exudates did not have a stimulant effect. Exploitation of walikadep and the long time required to reach harvestable size resulted in the scarcity of the plant in the natural habitat. Plant growth was faster in-situ than ex-situ; and fast growth was obtained from middle part cuttings treated with vermicompost. Biodiversity index after exploitation was higher than before exploitation, possibly due to the toxic and allellopathic effect (phenolics) of the plant. Based on these findings, further research is needed to examine the toxic effects of the leave and stem extract of walikadep and their allelopathic effects. We recommend that people of Blumah village to stop using walikadep as the stimulant. The local people, village government in the regional and central levels, and perhutani should do an integrated efforts to conserve walikadep through Pengamanan Terpadu Konservasi Walikadep Lestari (PTKWL) program, so this population of this plant in the natural habitat can be maintained.

Keywords: utilization, medical plants, traditional, Tetastigma glabratum

Procedia PDF Downloads 280
4297 The Impact of Roof Thermal Performance on the Indoor Thermal Comfort in a Natural Ventilated Building Envelope in Hot Climatic Climates

Authors: J. Iwaro, A. Mwasha, K. Ramsubhag

Abstract:

Global warming has become a threat of our time. It poses challenges to the existence of beings on earth, the built environment, natural environment and has made a clear impact on the level of energy and water consumption. As such, increase in the ambient temperature increases indoor and outdoor temperature level of the buildings which brings about the use of more energy and mechanical air conditioning systems. In addition, in view of the increased modernization and economic growth in the developing countries, a significant amount of energy is being used, especially those with hot climatic conditions. Since modernization in developing countries is rising rapidly, more pressure is being placed on the buildings and energy resources to satisfy the indoor comfort requirements. This paper presents a sustainable passive roof solution as a means of reducing energy cooling loads for satisfying human comfort requirements in a hot climate. As such, the study based on the field study data discusses indoor thermal roof design strategies for a hot climate by investigating the impacts of roof thermal performance on indoor thermal comfort in naturally ventilated building envelope small scaled structures. In this respect, the traditional concrete flat roof, corrugated galvanised iron roof and pre-painted standing seam roof were used. The experiment made used of three identical small scale physical models constructed and sited on the roof of a building at the University of the West Indies. The results show that the utilization of insulation in traditional roofing systems will significantly reduce heat transfer between the internal and ambient environment, thus reducing the energy demand of the structure and the relative carbon footprint of a structure per unit area over its lifetime. Also, the application of flat slab concrete roofing system showed the best performance as opposed to the metal roof sheeting alternative systems. In addition, it has been shown experimentally through this study that a sustainable passive roof solution such as insulated flat concrete roof in hot dry climate has a better cooling strength that can provide building occupant with a better thermal comfort, conducive indoor conditions and energy efficiency.

Keywords: building envelope, roof, energy consumption, thermal comfort

Procedia PDF Downloads 271
4296 Influence of Single and Multiple Skin-Core Debonding on Free Vibration Characteristics of Innovative GFRP Sandwich Panels

Authors: Indunil Jayatilake, Warna Karunasena, Weena Lokuge

Abstract:

An Australian manufacturer has fabricated an innovative GFRP sandwich panel made from E-glass fiber skin and a modified phenolic core for structural applications. Debonding, which refers to separation of skin from the core material in composite sandwiches, is one of the most common types of damage in composites. The presence of debonding is of great concern because it not only severely affects the stiffness but also modifies the dynamic behaviour of the structure. Generally, it is seen that the majority of research carried out has been concerned about the delamination of laminated structures whereas skin-core debonding has received relatively minor attention. Furthermore, it is observed that research done on composite slabs having multiple skin-core debonding is very limited. To address this gap, a comprehensive research investigating dynamic behaviour of composite panels with single and multiple debonding is presented. The study uses finite-element modelling and analyses for investigating the influence of debonding on free vibration behaviour of single and multilayer composite sandwich panels. A broad parametric investigation has been carried out by varying debonding locations, debonding sizes and support conditions of the panels in view of both single and multiple debonding. Numerical models were developed with Strand7 finite element package by innovatively selecting the suitable elements to diligently represent their actual behavior. Three-dimensional finite element models were employed to simulate the physically real situation as close as possible, with the use of an experimentally and numerically validated finite element model. Comparative results and conclusions based on the analyses are presented. For similar extents and locations of debonding, the effect of debonding on natural frequencies appears greatly dependent on the end conditions of the panel, giving greater decrease in natural frequency when the panels are more restrained. Some modes are more sensitive to debonding and this sensitivity seems to be related to their vibration mode shapes. The fundamental mode seems generally the least sensitive mode to debonding with respect to the variation in free vibration characteristics. The results indicate the effectiveness of the developed three-dimensional finite element models in assessing debonding damage in composite sandwich panels

Keywords: debonding, free vibration behaviour, GFRP sandwich panels, three dimensional finite element modelling

Procedia PDF Downloads 315
4295 Interactive Multiple Functions User Interface

Authors: Manjit Singh Sidhu, Waleed Maqableh, Jee Geak Ying

Abstract:

Tangible user interfaces (TUI) that employ markers in the augmented reality (AR) environment has hampered the interactivity between the user and the software application. This is because the user lacks focus on visualizing the contents due to the interaction mechanisms whereby multiple markers may need to be used to perform a particular function. In this research, we have designed a novel TUI user interface where multiple functions could be triggered similar to a natural keyboard thus allowing user to focus more on its digital contents such as 2D/3D, text input, animation and sound. Test results of the user interface with potential users and HCI experts revealed that the multiple functions user interface was new, preferred and appreciated more as opposed to marker based user interface.

Keywords: multimedia, augmented reality, engineering, user interface, visualization

Procedia PDF Downloads 449
4294 An Overview of Heating and Cooling Techniques Used in Green Buildings

Authors: Umesh Kumar Soni, Suresh Kumar Soni, S. R. Awasthi

Abstract:

Worldwide biggest difficulties are climate change, future availability of fossil fuels, and economical feasibility of renewable energy. They force us to use to a greater extent renewable energy and develop suitable hybrid renewable systems. Building heating/cooling consumes significant amount of energy. It can be conserved by use of proper heating/cooling techniques. This paper reviews and critically analyzes various active, passive and hybrid heating/cooling techniques used in green buildings.

Keywords: natural ventilation, energy conservation, hybrid ventilation techniques, climate change

Procedia PDF Downloads 605
4293 Numerical Investigation of Turbulent Inflow Strategy in Wind Energy Applications

Authors: Arijit Saha, Hassan Kassem, Leo Hoening

Abstract:

Ongoing climate change demands the increasing use of renewable energies. Wind energy plays an important role in this context since it can be applied almost everywhere in the world. To reduce the costs of wind turbines and to make them more competitive, simulations are very important since experiments are often too costly if at all possible. The wind turbine on a vast open area experiences the turbulence generated due to the atmosphere, so it was of utmost interest from this research point of view to generate the turbulence through various Inlet Turbulence Generation methods like Precursor cyclic and Kaimal Spectrum Exponential Coherence (KSEC) in the computational simulation domain. To be able to validate computational fluid dynamic simulations of wind turbines with the experimental data, it is crucial to set up the conditions in the simulation as close to reality as possible. This present work, therefore, aims at investigating the turbulent inflow strategy and boundary conditions of KSEC and providing a comparative analysis alongside the Precursor cyclic method for Large Eddy Simulation within the context of wind energy applications. For the generation of the turbulent box through KSEC method, firstly, the constrained data were collected from an auxiliary channel flow, and later processing was performed with the open-source tool PyconTurb, whereas for the precursor cyclic, only the data from the auxiliary channel were sufficient. The functionality of these methods was studied through various statistical properties such as variance, turbulent intensity, etc with respect to different Bulk Reynolds numbers, and a conclusion was drawn on the feasibility of KSEC method. Furthermore, it was found necessary to verify the obtained data with DNS case setup for its applicability to use it as a real field CFD simulation.

Keywords: Inlet Turbulence Generation, CFD, precursor cyclic, KSEC, large Eddy simulation, PyconTurb

Procedia PDF Downloads 96
4292 Liquid-Liquid Plug Flow Characteristics in Microchannel with T-Junction

Authors: Anna Yagodnitsyna, Alexander Kovalev, Artur Bilsky

Abstract:

The efficiency of certain technological processes in two-phase microfluidics such as emulsion production, nanomaterial synthesis, nitration, extraction processes etc. depends on two-phase flow regimes in microchannels. For practical application in chemistry and biochemistry it is very important to predict the expected flow pattern for a large variety of fluids and channel geometries. In the case of immiscible liquids, the plug flow is a typical and optimal regime for chemical reactions and needs to be predicted by empirical data or correlations. In this work flow patterns of immiscible liquid-liquid flow in a rectangular microchannel with T-junction are investigated. Three liquid-liquid flow systems are considered, viz. kerosene – water, paraffin oil – water and castor oil – paraffin oil. Different flow patterns such as parallel flow, slug flow, plug flow, dispersed (droplet) flow, and rivulet flow are observed for different velocity ratios. New flow pattern of the parallel flow with steady wavy interface (serpentine flow) has been found. It is shown that flow pattern maps based on Weber numbers for different liquid-liquid systems do not match well. Weber number multiplied by Ohnesorge number is proposed as a parameter to generalize flow maps. Flow maps based on this parameter are superposed well for all liquid-liquid systems of this work and other experiments. Plug length and velocity are measured for the plug flow regime. When dispersed liquid wets channel walls plug length cannot be predicted by known empirical correlations. By means of particle tracking velocimetry technique instantaneous velocity fields in a plug flow regime were measured. Flow circulation inside plug was calculated using velocity data that can be useful for mass flux prediction in chemical reactions.

Keywords: flow patterns, hydrodynamics, liquid-liquid flow, microchannel

Procedia PDF Downloads 395
4291 The Emergence of Memory at the Nanoscale

Authors: Victor Lopez-Richard, Rafael Schio Wengenroth Silva, Fabian Hartmann

Abstract:

Memcomputing is a computational paradigm that combines information processing and storage on the same physical platform. Key elements for this topic are devices with an inherent memory, such as memristors, memcapacitors, and meminductors. Despite the widespread emergence of memory effects in various solid systems, a clear understanding of the basic microscopic mechanisms that trigger them is still a puzzling task. We report basic ingredients of the theory of solid-state transport, intrinsic to a wide range of mechanisms, as sufficient conditions for a memristive response that points to the natural emergence of memory. This emergence should be discernible under an adequate set of driving inputs, as highlighted by our theoretical prediction and general common trends can be thus listed that become a rule and not the exception, with contrasting signatures according to symmetry constraints, either built-in or induced by external factors at the microscopic level. Explicit analytical figures of merit for the memory modulation of the conductance are presented, unveiling very concise and accessible correlations between general intrinsic microscopic parameters such as relaxation times, activation energies, and efficiencies (encountered throughout various fields in Physics) with external drives: voltage pulses, temperature, illumination, etc. These building blocks of memory can be extended to a vast universe of materials and devices, with combinations of parallel and independent transport channels, providing an efficient and unified physical explanation for a wide class of resistive memory devices that have emerged in recent years. Its simplicity and practicality have also allowed a direct correlation with reported experimental observations with the potential of pointing out the optimal driving configurations. The main methodological tools used to combine three quantum transport approaches, Drude-like model, Landauer-Buttiker formalism, and field-effect transistor emulators, with the microscopic characterization of nonequilibrium dynamics. Both qualitative and quantitative agreements with available experimental responses are provided for validating the main hypothesis. This analysis also shades light on the basic universality of complex natural impedances of systems out of equilibrium and might help pave the way for new trends in the area of memory formation as well as in its technological applications.

Keywords: memories, memdevices, memristors, nonequilibrium states

Procedia PDF Downloads 97
4290 Experimental Investigation on Mechanical Properties of Rice Husk Filled Jute Reinforced Composites

Authors: Priyankar P. Deka, Sutanu Samanta

Abstract:

This paper describes the development of new class of epoxy based hybrid composites reinforced with jute and filled with rice husk flour. Rice husk flour is added in 0%, 1%, 3%, 5% by weight. Epoxy resin and triethylene tetramine (T.E.T.A) is used as matrix and hardener respectively. It investigates the mechanical properties of the composites and a comparison is done for monolithic jute composite and the filled ones. The specimens are prepared according to the ASTM standards and experimentation is carried out using INSTRON 8801. The result shows that with the increase of filler percentage the tensile properties increases but compressive and flexural properties decreases.

Keywords: jute, mechanical characterization, natural fiber, rice husk

Procedia PDF Downloads 285
4289 Impact of Charging PHEV at Different Penetration Levels on Power System Network

Authors: M. R. Ahmad, I. Musirin, M. M. Othman, N. A. Rahmat

Abstract:

Plug-in Hybrid-Electric Vehicle (PHEV) has gained immense popularity in recent years. PHEV offers numerous advantages compared to the conventional internal-combustion engine (ICE) vehicle. Millions of PHEVs are estimated to be on the road in the USA by 2020. Uncoordinated PHEV charging is believed to cause severe impacts to the power grid; i.e. feeders, lines and transformers overload and voltage drop. Nevertheless, improper PHEV data model used in such studies may cause the findings of their works is in appropriated. Although smart charging is more attractive to researchers in recent years, its implementation is not yet attainable on the street due to its requirement for physical infrastructure readiness and technology advancement. As the first step, it is finest to study the impact of charging PHEV based on real vehicle travel data from National Household Travel Survey (NHTS) and at present charging rate. Due to the lack of charging station on the street at the moment, charging PHEV at home is the best option and has been considered in this work. This paper proposed a technique that comprehensively presents the impact of charging PHEV on power system networks considering huge numbers of PHEV samples with its traveling data pattern. Vehicles Charging Load Profile (VCLP) is developed and implemented in IEEE 30-bus test system that represents a portion of American Electric Power System (Midwestern US). Normalization technique is used to correspond to real time loads at all buses. Results from the study indicated that charging PHEV using opportunity charging will have significant impacts on power system networks, especially whereas bigger battery capacity (kWh) is used as well as for higher penetration level.

Keywords: plug-in hybrid electric vehicle, transportation electrification, impact of charging PHEV, electricity demand profile, load profile

Procedia PDF Downloads 287
4288 Understanding the Accumulation of Microplastics in Riverbeds and Soils

Authors: Gopala Krishna Darbha

Abstract:

Microplastics (MPs) are secondary fragments of large-sized plastic debris released into the environment and fall in the size range of less than 5 mm. Though reports indicate the abundance of MPs in both riverine and soil environments, their fate is still not completely understood due to the complexity of natural conditions. Mineral particles are ubiquitous in the rivers and may play a vital role in accumulating MPs to the riverbed, thus affecting the benthic life and posing a threat to the river's health. Apart, the chemistry (pH, ionic strength, humics) at the interface can be very prominent. The MPs can also act as potential vectors to transport other contaminants in the environment causing secondary water pollution. The present study focuses on understanding the interaction of MPs with weathering sequence of minerals (feldspar, kaolinite and gibbsite) under batch mode under relevant environmental and natural conditions. Simultaneously, we performed stability studies and transport (column) experiments to understand the mobility of MPs under varying soil solutions (SS) chemistry and the influence of contaminants (CuO nanoparticles). Results showed that the charge and morphology of the gibbsite played an significant role in sorption of NPs (108.1 mg/g) compared to feldspar (7.7 mg/g) and kaolinite (11.9 mg/g). The Fourier transform infrared spectroscopy data supports the complexation of NPs with gibbsite particles via hydrogen bonding. In case of feldspar and kaolinite, a weak interaction with NPs was observed which can be due to electrostatic repulsions and low surface area to volume ration of the mineral particles. The study highlights the enhanced mobility in presence of feldspar and kaolinite while gibbsite rich zones can cause entrapment of NPs accumulating in the riverbeds. In the case of soils, in the absence of MPs, a very high aggregation of CuO NPs observed in SS extracted from black, lateritic, and red soils, which can be correlated with ionic strength (IS) and type of ionic species. The sedimentation rate (Ksed(1/h)) for CuO NPs was >0.5 h−1 in the case of these SS. Interestingly, the stability and sedimentation behavior of CuO NPs varied significantly in the presence of MPs. The Ksed for CuO NPs decreased to half and found <0.25 h−1 in the presence of MPs in all SS. C/C0 values in breakthrough curves increased drastically (black < alluvial < laterite < red) in the presence of MPs. Results suggest that the release of MPs in the terrestrial ecosystem is a potential threat leading to increased mobility of metal nanoparticles in the environment.

Keywords: microplastics, minerals, sorption, soils

Procedia PDF Downloads 90
4287 Contribution of Algerians Local Materials on the Compressive Strengths of Concrete: Experimental and Numerical Study

Authors: Mohamed Lyes Kamel Khouadjia, Bouzidi Mezghiche

Abstract:

The evolution in the civil engineering and carried out more consumption of aggregates and particularly the sand. Due to the depletion of natural reserves of sand, it is necessary to focus on the use of local materials such as crushed sand, river sand and dune sand, mineral additions. The aim of this work is to improve the state of knowledge on the compressive strengths of crushed sands with several mixtures (dune sand, river sand, pozzolan, and slag). The obtained results were compared with numerical results obtained with the software Béton Lab Pro 3.

Keywords: crushed sand, river sand, dune sand, pouzzolan, slag, compressive strengths, Béton Lab Pro 3

Procedia PDF Downloads 325
4286 Assessing the Financial Impact of Federal Benefit Program Enrollment on Low-income Households

Authors: Timothy Scheinert, Eliza Wright

Abstract:

Background: Link Health is a Boston-based non-profit leveraging in-person and digital platforms to promote health equity. Its primary aim is to financially support low-income individuals through enrollment in federal benefit programs. This study examines the monetary impact of enrollment in several benefit programs. Methodologies: Approximately 17,000 individuals have been screened for eligibility via digital outreach, community events, and in-person clinics. Enrollment and financial distributions are evaluated across programs, including the Affordable Connectivity Program (ACP), Lifeline, LIHEAP, Transitional Aid to Families with Dependent Children (TAFDC), and the Supplemental Nutrition Assistance Program (SNAP). Major Findings: A total of 1,895 individuals have successfully applied, collectively distributing an estimated $1,288,152.00 in aid. The largest contributors to this sum include: ACP: 1,149 enrollments, $413,640 distributed annually. Child Care Financial Assistance (CCFA): 15 enrollments, $240,000 distributed annually. Lifeline: 602 enrollments, $66,822 distributed annually. LIHEAP: 25 enrollments, $48,750 distributed annually. SNAP: 41 enrollments, $123,000 distributed annually. TAFDC: 21 enrollments, $341,760 distributed annually. Conclusions: These results highlight the role of targeted outreach and effective enrollment processes in promoting access to federal benefit programs. High enrollment rates in ACP and Lifeline demonstrate a considerable need for affordable broadband and internet services. Programs like CCFA and TAFDC, despite lower enrollment numbers, provide sizable support per individual. This analysis advocates for continued funding of federal benefit programs. Future efforts can be made to develop screening tools that identify eligibility for multiple programs and reduce the complexity of enrollment.

Keywords: benefits, childcare, connectivity, equity, nutrition

Procedia PDF Downloads 27
4285 A Review of Security Attacks and Intrusion Detection Schemes in Wireless Sensor Networks: A Survey

Authors: Maleh Yassine, Ezzati Abdellah

Abstract:

Wireless Sensor Networks (WSNs) are currently used in different industrial and consumer applications, such as earth monitoring, health related applications, natural disaster prevention, and many other areas. Security is one of the major aspects of wireless sensor networks due to the resource limitations of sensor nodes. However, these networks are facing several threats that affect their functioning and their life. In this paper we present security attacks in wireless sensor networks, and we focus on a review and analysis of the recent Intrusion Detection schemes in WSNs.

Keywords: wireless sensor networks, security attack, denial of service, IDS, cluster-based model, signature based IDS, hybrid IDS

Procedia PDF Downloads 385
4284 Assessment of Impact of Urbanization in Drainage Urban Systems, Cali-Colombia

Authors: A. Caicedo Padilla, J. Zambrano Nájera

Abstract:

Cali, the capital of Valle del Cauca and the second city of Colombia, is located in the Cauca River Valley between the Western and Central Cordillera that is South West of the country. The topography of the city is mainly flat, but it is possibly to find mountains in the west. The city has increased urbanization during XX century, especially since 1958 when started a rapid growth due to migration of people from other parts of the region. Much of that population has settled in eastern of Cali, an area originally intended for cane cultivation and a zone of flood from Cauca River and its tributaries. Due to the unplanned migration, settling was inadequate and produced changes in natural dynamics of the basins, which has resulted in increases in runoff volumes, peak flows and flow velocities, that in turn increases flood risk. Sewerage networks capacity were not enough for this higher runoff volume, because in first term they were not adequately designed and built, causing its failure. This in turn generates increasingly recurrent floods generating considerable effects on the economy and development of normal activities in Cali. Thus, it becomes very important to know hydrological behavior of Urban Watersheds. This research aims to determine the impact of urbanization on hydrology of watersheds with very low slopes. The project aims to identify changes in natural drainage patterns caused by the changes made on landscape. From the identification of such modifications it will be defined the most critical areas due to recurring flood events in the city of Cali. Critical areas are defined as areas where the sewerage system does not work properly as surface runoff increases considerable with storm events, and floods are recurrent. The assessment will be done from the analysis of Geographic Information Systems (GIS) theme layers from CVC Environmental Institution of Regional Control in Valle del Cauca, hydrological data and disaster database developed by OSSO Corporation. Rainfall data from a network and historical stream flow data will be used for analysis of historical behavior and change of precipitation and hydrological response according to homogeneous zones characterized by EMCALI S.A. public utility enterprise of Cali in 1999.

Keywords: drainage systems, land cover changes, urban hydrology, urban planning

Procedia PDF Downloads 264
4283 In Silico Study of Alpha glucosidase Inhibitors by Flavonoids

Authors: Boukli Hacene Faiza, Soufi Wassila, Ghalem Said

Abstract:

The oral antidiabetics drugs such as alpha glucosidase inhibitors present undesirable effects like acarbose. Flavonoids are class of molecules widely distributed in plants, for this reason we are interested in our work to study the inhibition in silico of alpha glucosidase by natural ligands ( flavonoids analogues) using molecular modeling methods using MOE (Molecular Operating Environment) software to predict their interaction with this enzyme with score energy, ADME /T tests and druglikeness properties experiments. Two flavonoids Beicalein and Apigenin have high binding affinity with alpha glucosidase with lower IC50 supposed potent inhibitors.

Keywords: alpha glucosidase, flavonoides analogues, drug research, molecular modeling

Procedia PDF Downloads 107
4282 Studying the Effect of Different Sizes of Carbon Fiber on Locally Developed Copper Based Composites

Authors: Tahir Ahmad, Abubaker Khan, Muhammad Kamran, Muhammad Umer Manzoor, Muhammad Taqi Zahid Butt

Abstract:

Metal Matrix Composites (MMC) is a class of weight efficient structural materials that are becoming popular in engineering applications especially in electronic, aerospace, aircraft, packaging and various other industries. This study focuses on the development of carbon fiber reinforced copper matrix composite. Keeping in view the vast applications of metal matrix composites,this specific material is produced for its unique mechanical and thermal properties i.e. high thermal conductivity and low coefficient of thermal expansion at elevated temperatures. The carbon fibers were not pretreated but coated with copper by electroless plating in order to increase the wettability of carbon fiber with the copper matrix. Casting is chosen as the manufacturing route for the C-Cu composite. Four different compositions of the composite were developed by varying the amount of carbon fibers by 0.5, 1, 1.5 and 2 wt. % of the copper. The effect of varying carbon fiber content and sizes on the mechanical properties of the C-Cu composite is studied in this work. The tensile test was performed on the tensile specimens. The yield strength decreases with increasing fiber content while the ultimate tensile strength increases with increasing fiber content. Rockwell hardness test was also performed and the result followed the increasing trend for increasing carbon fibers and the hardness numbers are 30.2, 37.2, 39.9 and 42.5 for sample 1, 2, 3 and 4 respectively. The microstructures of the specimens were also examined under the optical microscope. Wear test and SEM also done for checking characteristic of C-Cu marix composite. Through casting may be a route for the production of the C-Cu matrix composite but still powder metallurgy is better to follow as the wettability of carbon fiber with matrix, in that case, would be better.

Keywords: copper based composites, mechanical properties, wear properties, microstructure

Procedia PDF Downloads 364