Search results for: conventional%20banking

Authors: Kadrefi Athanasia, Fronimaki Evgenia, Mavri Maria

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3D Printing (3DP) is a distinct, disruptive technology that belongs to a wider group of manufacturing technologies, Additive Manufacturing (AM). In 3DP, a custom digital file turns into a solid object using a single computer and a 3D printer. Among multiple advantages, 3DP offers production with fewer steps compared to conventional manufacturing, lower production costs, and customizable designs. 3DP can be performed by several techniques, while the most common is Fused Deposition Modeling (FDM). FDM belongs to a wider group of AM techniques, material extrusion, where a digital file converts into a solid object using raw material (called filament) melted in high temperatures. As in most manufacturing procedures, environmental issues have been raised here, too. This study aims to review the literature on issues that determine technical and mechanical factors that affect the sustainability and resilience of a final 3D-printed object. The research focuses on the collection of papers that deal with 3D printing techniques and use keywords or phrases like ‘3D printed objects’, ‘factors of 3DP sustainability’, ‘waste materials,’ ‘infill patterns,’ and ‘support structures.’ After determining factors, a pilot survey will be conducted at the 3D Printing Lab in order to define the significance of each factor in the final 3D printed object.

Keywords: additive manufacturing, 3D printing, sustainable manufacturing, sustainable production

Procedia PDF Downloads 38

Authors: Cheng-Jhe Lee, Chiun-Chieh Hsu

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Due to the rapid development of the Internet and the increased availability of digital documents, the excessive information on the Internet has led to information overflow problem. In order to solve these problems for effective information retrieval, document clustering in text mining becomes a popular research topic. Clustering is the unsupervised classification of data items into groups without the need of training data. Many conventional document clustering methods perform inefficiently for large document collections because they were originally designed for relational database. Therefore they are impractical in real-world document clustering and require special handling for high dimensionality and high volume. We propose the FIHC (Frequent Itemset-based Hierarchical Clustering) method, which is a hierarchical clustering method developed for document clustering, where the intuition of FIHC is that there exist some common words for each cluster. FIHC uses such words to cluster documents and builds hierarchical topic tree. In this paper, we combine FIHC algorithm with ontology to solve the semantic problem and mine the meaning behind the words in documents. Furthermore, we use the closed frequent itemsets instead of only use frequent itemsets, which increases efficiency and scalability. The experimental results show that our method is more accurate than those of well-known document clustering algorithms.

Keywords: FIHC, documents clustering, ontology, closed frequent itemset

Procedia PDF Downloads 377

Authors: Gaurav Datta, Sourav Ghosh, Rahul Roy

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The incorporation of silica fume into the normal concrete is a routine one in the present days to produce the tailor made high strength and high performance concrete. The design parameters are increasing with the incorporation of silica fume in conventional concrete and the mix proportioning is becoming complex. The main objective of this paper has been made to investigate the different mechanical properties like compressive strength, permeability, porosity, density, modulus of elasticity, compacting factor, slump of concrete incorporating silica fume. In this present paper 5 (five) mix of concrete incorporating silica fume is cast to perform experiments. These experiments were carried out by replacing cement with different percentages of silica fume at a single constant water-cementitious materials ratio keeping other mix design variables constant. The silica fume was replaced by 0%, 5%, 10%, 15% and 20% for water-cementitious materials (w/cm) ratio for 0.40. For all mixes compressive strengths were determined at 24 hours, 7 and 28 days for 100 mm and 150 mm cubes. Other properties like permeability, porosity, density, modulus of elasticity, compacting factor, and slump were also determined for five mixes of concrete.

Keywords: high performance concrete, high strength concrete, silica fume, strength

Procedia PDF Downloads 272

Authors: Liseane Padilha Thives, Mayara S. S. Lima, João Victor Staub De Melo, Glicério Trichês

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Red mud is a waste resulting from the processing of bauxite to alumina, the raw material of the production of aluminum. The large quantity of red mud generated and inadequately disposed in the environment has motivated researchers to develop methods for reinsertion of this waste into the productive cycle. This work aims to evaluate the resistance to permanent deformation of dense asphalt mixtures with red mud filler. The red mud was characterized by tests of X-ray diffraction, fluorescence, specific mass, laser granulometry, pH and scanning electron microscopy. For the analysis of the influence of the quantity of red mud in the mechanical performance of asphalt mixtures, a total filler content of 7% was established. Asphalt mixtures with 3%, 5% and 7% red mud were produced. A conventional mixture with 7% stone powder filler was used as reference. The asphalt mixtures were evaluated for performance to permanent deformation in the French Rutting Tester (FRT) traffic simulator. The mixture with 5% red mud presented greater resistance to permanent deformation with rutting depth at 30,000 cycles of 3.50%. The asphalt mixtures with red mud presented better performance, with reduction of the rutting of 12.63 to 42.62% in relation to the reference mixture. This study confirmed the viability of reinserting the red mud in the production chain and possible usage in the construction industry. The red mud as filler in asphalt mixtures is a reuse option of this waste and mitigation of the disposal problems, as well as being an environmentally friendly alternative.

Keywords: asphalt mixtures, permanent deformation, red mud, pavements

Procedia PDF Downloads 267

Authors: Vipul Shiralkar, Rohit Khadilkar, Shekhar Kulkarni, Ismail Mullani, Omkar Malvankar

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The use of water cooler has increased and become an important appliance in the world of global warming. Most of the coolers are electrically operated. In this study an experimental setup of evaporative water cooler using solar energy is designed and developed. It works on the principle of heat transfer using evaporation of water. Water is made to flow through copper tubes arranged in a specific array manner. Cotton plug is wrapped on copper tubes and rubber pipes are arranged in the same way as copper tubes above it. Water percolated from rubber pipes is absorbed by cotton plug. The setup has 40L water carrying capacity with forced cooling arrangement and variable speed fan which uses solar energy stored in 20Ah capacity battery. Fan speed greatly affects the temperature drop. Tests were performed at different fan speed. Maximum temperature drop achieved was 90C at 1440 rpm of fan speed. This temperature drop is very attractive. This water cooler uses solar energy hence it is cost efficient and it is affordable to rural community as well. The cooler is free from any harmful emissions like other refrigerants and hence environmental friendly. Very less maintenance is required as compared to the conventional electrical water cooler.

Keywords: evaporation, cooler, energy, copper, solar, cost

Procedia PDF Downloads 299

Authors: Olivia Bory Devisme, Denis Genon-Catalot, Frederic Alicalapa, Pierre-Olivier Lucas De Peslouan, Jean-Pierre Chabriat

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In the context of climate change, it is essential that island territories gain energy autonomy. Currently mostly dependent on fossil fuels, the island of Reunion lo- cated in the Indian Ocean nevertheless has a high potential for solar energy. As the market for photovoltaic panels has been growing in recent years, the issues of energy losses linked to the multiple conversions from direct current to alternating current are emerging. In order to quantify these advantages and disadvantages by a comparative study, this document present the measurements carried out on a direct current test bench, particularly for lighting, ventilation, air condi- tioning and office equipment for the tertiary sector. All equipment is supplied with DC power from energy produced by photovoltaic panels. A weather sta- tion, environmental indoor sensors, and drivers are also used to control energy. Self-consumption is encouraged in order to manage different priorities between user consumption and energy storage in a lithium iron phosphate battery. The measurements are compared to a conventional electrical architecture (DC-AC- DC) for energy consumption, equipment overheating, cost, and life cycle analysis.

Keywords: DC microgrids, solar energy, smart buildings, storage

Procedia PDF Downloads 146

Authors: Salha Abdullah Ali Al-Shamrani, Maha Muhammad Dhaher Aljuhani, Eman Ali Ahmed Aldhaheri

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With the proliferation of Internet of Things (IoT) devices in various industries, there has been a concurrent rise in security vulnerabilities, particularly spoofing attacks. This study explores the potential of blockchain technology in enhancing the security of IoT systems and mitigating these attacks. Blockchain's decentralized and immutable ledger offers significant promise for improving data integrity, transaction transparency, and tamper-proofing. This research develops and implements a blockchain-based IoT architecture and a reference network to simulate real-world scenarios and evaluate a blockchain-integrated intrusion detection system. Performance measures including time delay, security, and resource utilization are used to assess the system's effectiveness, comparing it to conventional IoT networks without blockchain. The results provide valuable insights into the practicality and efficacy of employing blockchain as a security mechanism, shedding light on the trade-offs between speed and security in blockchain deployment for IoT. The study concludes that despite minor increases in time consumption, the security benefits of incorporating blockchain technology into IoT systems outweigh potential drawbacks, demonstrating a significant potential for blockchain in bolstering IoT security.

Keywords: internet of things, spoofing, IoT, access control, blockchain, raspberry pi

Procedia PDF Downloads 48

Authors: Marvin Ricardo Awarab

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There has never been a greater need for telecom services. The Internet of Things (IoT), 5G networking, and edge computing are the driving forces behind this increased demand. The fierce demand offers communications service providers significant income opportunities. The telecom sector is centered on automation, and realizing a digital operation that functions as a real-time business will be crucial for the industry as a whole. Automation in telecom refers to the application of technology to create a more effective, quick, and scalable alternative to the conventional method of operating the telecom industry. With the promotion of 5G and the Internet of Things (IoT), telecom companies will continue to invest extensively in telecom automation technology. Automation offers benefits in the telecom industry; developing countries such as Namibia may not fully tap into such benefits because of the lack of funds and infrastructural resources to invest in automation. This paper fully investigates the benefits of automation in the telecom industry. Furthermore, the paper identifies hiccups that developing countries such as Namibia face in their quest to fully introduce automation in the telecom industry. Additionally, the paper proposes possible avenues that Namibia, as a developing country, adopt investing in automation infrastructural resources with the aim of reaping the full benefits of automation in the telecom industry.

Keywords: automation, development, internet, internet of things, network, telecom, telecommunications policy, 5G

Procedia PDF Downloads 50

Authors: Deepti Mishra, Arindam Modak, K. K. Pant, Xiu Song Zhao

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The promotional effect of mixed ceria-zirconia oxides (CZO) over the Mo/HZSM-5 catalyst for methane dehydroaromatization (MDA) reaction was studied. The surface and structural properties of the synthesized catalyst were characterized using a range of spectroscopic and microscopic techniques, and the correlation between catalytic properties and its performance for MDA reaction is discussed. The impregnation of CZO solid solution on Mo/HZSM-5 was observed to give an excellent catalytic performance and improved benzene formation rate (4.5 μmol/gcat. s) as compared to the conventional Mo/HZSM-5 (3.1 μmol/gcat. s) catalyst. In addition, a significant reduction in coke formation was observed in the CZO-modified Mo/HZSM-5 catalyst. The prevailing comprehension for higher catalytic activity could be because of the redox properties of CZO deposited Mo/HZSM-5, which acts as a selective oxygen supplier and performs hydrogen combustion during the reaction, which is indirectly probed by O₂-TPD and H₂-TPR analysis. The selective hydrogen combustion prevents the over-oxidation of aromatic species formed during the reaction while the generated steam helps in reducing the amount of coke generated in the MDA reaction. Thus, the advantage of CZO incorporated Mo/HZSM-5 is manifested as it promotes the reaction equilibrium to shift towards the formation of benzene which is favourable for MDA reaction.

Keywords: Mo/HZSM-5, ceria-zirconia (CZO), in-situ combustion, methane dehydroaromatization

Procedia PDF Downloads 81

Authors: Mohammad Mardi

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Generally, the resistivity is high in oil layer and low in water layer. Yet there are intervals of oil-bearing zones showing low resistivity, high porosity, and low resistance. In the typical example, well A (depth: 4341.5-4372.0m), both Spectral Gamma Ray (SGR) and Corrected Gamma Ray (CGR) are relatively low; porosity varies from 12-22%. Above 4360 meters, the reservoir shows the conventional positive difference between deep and shallow resistivity with high resistance; below 4360m, the reservoir shows a negative difference with low resistance, especially at depths of 4362.4 meters and 4371 meters, deep resistivity is only 2Ω.m, and the CAST-V imaging map shows that there are low resistance substances contained in the pores or matrix in the reservoirs of this interval. The rock slice analysis data shows that the pyrite volume is 2-3% in the interval 4369.08m-4371.55m. A comprehensive analysis on the volume of shale (Vsh), porosity, invasion features of resistivity, mud logging, and mineral volume indicates that the possible causes for the negative difference between deep and shallow resistivities with relatively low resistance are erosional pores, caves, micritic texture and the presence of pyrite. Full-bore Drill Stem Test (DST) verified 4991.09 bbl/d in this interval. To identify and thoroughly characterize low resistivity intervals coring, Nuclear Magnetic Resonance (NMR) logging and further geological evaluation are needed.

Keywords: low resistivity pay, carbonates petrophysics, microporosity, porosity

Procedia PDF Downloads 146

Authors: Joseph E. Hummer

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An efficient freeway system will be essential to the development of Africa, and interchanges are a key to that efficiency. Around the world, many interchanges between freeways and surface streets, called service interchanges, are of the diamond configuration, and interchanges using roundabouts or loop ramps are also popular. However, many diamond interchanges have serious operational problems, interchanges with roundabouts fail at high demand levels, and loops use lots of expensive land. Newer service interchange designs provide other options. The most popular new interchange design in the US at the moment is the double crossover diamond (DCD), also known as the diverging diamond. The DCD has enormous potential, but also has several significant limitations. The objectives of this paper are to review new service interchange options and to highlight some of the main features of those alternatives. The paper tests four conventional and seven unconventional designs using seven measures related to efficiency, cost, and safety. The results show that there is no superior design in all measures investigated. The DCD is better than most designs tested on most measures examined. However, the DCD was only superior to all other designs for bridge width. The DCD performed relatively poorly for capacity and for serving pedestrians. Based on the results, African freeway designers are encouraged to investigate the full range of alternatives that could work at the spot of interest. Diamonds and DCDs have their niches, but some of the other designs investigated could be optimum at some spots.

Keywords: interchange, diamond, diverging diamond, capacity, safety, cost

Procedia PDF Downloads 233

Authors: Zemmouri Hassiba, Lounici Hakim, Mameri Nabil

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Dried crushed seeds of Moringa oleifera contain an effective soluble protein; a natural cationic polyelectrolyte which causes coagulation. The present study aims to investigate the performance of Moringa oleifera seed extract as natural coagulant in clarification of secondary wastewater treatment highly charged in colloidal. A series of Jar tests was undertaken using raw wastewater providing from secondary decanter of Reghaia municipal wastewater treatment plant (MWWTP) located in East of Algiers, Algeria. Coagulation flocculation performance of Moringa oleifera was evaluated through supernatant residual turbidity. Various influence parameters namely Moringa oleifera dosage and pH have been considered. Tests on Reghaia wastewater, having 129 NTU of initial turbidity, showed a removal of 69.45% of residual turbidity with only 1.5 mg/l of Moringa oleifera. This sufficient removal capability encourages the use of this bioflocculant for treatment of turbid waters. Based on this result, the coagulant seed extract of Moringa oleifera is better suited to clarify municipal wastewater by removing turbidity. Indeed, Moringa oleifera which is a natural resource available locally (South of Algeria) coupled to the non-toxicity, biocompatibility and biodegradability, may be a very interesting alternative to the conventional coagulants used so far.

Keywords: coagulation flocculation, colloids, moringa oleifera, secondary wastewater

Procedia PDF Downloads 295

Authors: Nandhini Ravi, Muthukumaran Shanmugam

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Metals are being replaced by thermoplastic polymer composites in automotive industries because of their low density, easiness to fabricate, low cost and good wear resistance. Complex polymer components consist of assemblies of smaller parts which can be joined by friction stir welding. This study deals with the additive friction stir welding of 15 wt.% glass fiber reinforced polyamide 66 composite which is a modified technique of the conventional friction stir welding by the addition of a filler plate for the heating of the composite work piece through the tool during the welding process. Welding at different combinations of tool rotational speed, travel speed and tool plunge depth was done after which the tensile strength of the respective experiments was determined. The maximum tensile strength obtained was 77 MPa which was 80% of the strength of the base material. The process parameters were optimized using the L9 orthogonal array and also the effect of individual welding parameter on the tensile strength was studied. The optimum parameter combination was determined with the help of ANOVA studies. The hardness of the welded joints was studied with the help of Shore Durometer which yielded the maximum of D 75.

Keywords: additive friction stir welding, polyamide 66, process parameters, thermoplastic polymer composite

Procedia PDF Downloads 136

Authors: Nursuhaili Najwa Masrol, Nur Hafizah Mohammed, Nur Nadhirah Rusyda Rosnan, Vijaya Subramaniam, Sim Choon Cheak

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Replanting in oil palm cultivation is vital to enable the introduction of planting materials and provides an opportunity to improve the road, drainage, terrace design, and planting density. Oil palm replanting is fundamentally necessary every 25 years. The adoption of the digital replanting blueprint is imperative as it can assist the Malaysia Oil Palm industry in addressing challenges such as labour shortages and limited expertise related to replanting tasks. Effective replanting planning should commence at least 6 months prior to the actual replanting process. Therefore, this study will help to plan and design the replanting blueprint with high-precision translation on the ground. With the advancement of geospatial technology, it is now feasible to engage in thoroughly researched planning, which can help maximize the potential yield. A blueprint designed before replanting is to enhance management’s ability to optimize the planting program, address manpower issues, or even increase productivity. In terrace planting blueprints, geographic tools have been utilized to design the roads, drainages, terraces, and planting points based on the ARM standards. These designs are mapped with location information and undergo statistical analysis. The geospatial approach is essential in precision agriculture and ensuring an accurate translation of design to the ground by implementing high-accuracy technologies. In this study, geospatial and remote sensing technologies played a vital role. LiDAR data was employed to determine the Digital Elevation Model (DEM), enabling the precise selection of terraces, while ortho imagery was used for validation purposes. Throughout the designing process, Geographical Information System (GIS) tools were extensively utilized. To assess the design’s reliability on the ground compared with the current conventional method, high-precision GPS instruments like EOS Arrow Gold and HIPER VR GNSS were used, with both offering accuracy levels between 0.3 cm and 0.5cm. Nearest Distance Analysis was generated to compare the design with actual planting on the ground. The analysis revealed that it could not be applied to the roads due to discrepancies between actual roads and the blueprint design, which resulted in minimal variance. In contrast, the terraces closely adhered to the GPS markings, with the most variance distance being less than 0.5 meters compared to actual terraces constructed. Considering the required slope degrees for terrace planting, which must be greater than 6 degrees, the study found that approximately 65% of the terracing was constructed at a 12-degree slope, while over 50% of the terracing was constructed at slopes exceeding the minimum degrees. Utilizing blueprint replanting promising strategies for optimizing land utilization in agriculture. This approach harnesses technology and meticulous planning to yield advantages, including increased efficiency, enhanced sustainability, and cost reduction. From this study, practical implementation of this technique can lead to tangible and significant improvements in agricultural sectors. In boosting further efficiencies, future initiatives will require more sophisticated techniques and the incorporation of precision GPS devices for upcoming blueprint replanting projects besides strategic progression aims to guarantee the precision of both blueprint design stages and its subsequent implementation on the field. Looking ahead, automating digital blueprints are necessary to reduce time, workforce, and costs in commercial production.

Keywords: replanting, geospatial, precision agriculture, blueprint

Procedia PDF Downloads 61

Authors: Ahlam Inayatullah Badrul Munir, M. Husaini A. Rahman, Mohd Sukri Hassan

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Real-time PCR is a molecular biology technique that is currently being widely used for halal services to differentiating between porcine and bovine DNA. The useful of technique become very important for student or workers (who works in the laboratory) to learn how the technique could be run smoothly without fail. Same concept with conventional PCR, real-time PCR also needed DNA template, primer, enzyme polymerase, dNTP, and buffer. The difference is in real-time PCR, have additional component namely fluorescent dye. The most common use of fluorescent dye in real-time PCR is SYBR green. The purpose of this study was to find out how sensitive, specific and efficient real-time PCR technique was combined with SYBR green method and specific primers of CYT b. The results showed that real-time PCR technique using SYBR Green, capable of detecting porcine and bovine DNA concentrations up to 0.0001 µl/ng. The level of efficiency for both types of DNA was 91% (90-110). Not only that in specific primer CYT b bovine primer could detect only bovine DNA, and porcine primer could detect only porcine primer. So, from the study could be concluded that real-time PCR technique that was combined with specific primer CYT b and SYBR green method, was sensitive, specific and efficient to detect porcine and bovine DNA.

Keywords: sensitivity, specificity, efficiency, real-time PCR, SYBR green, Cytochrome b, porcine DNA, bovine DNA

Procedia PDF Downloads 299

Authors: Ali Reza Ghaffari, Hassan Saghi

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Given the limitation of fossil resources to supply energy to buildings, recent years have seen a revival of interest in new technologies that produce the energy using new forms of energy in many developed countries. In this research, first the potentials of new energies in Iran are discussed and then based on case studies undertaken in a building in Tehran, the effects of utilizing new solar energy technology for supplying the energy of buildings are investigated. Then, by analyzing the data recorded over a four-year period, the technical performance of this system is investigated. According to the experimental operation plan, this system requires an auxiliary heating circuit for continuous operation over a year. Also, in the economic analysis, real conditions are considered and the results are recorded based on long-term data. Considering the purchase and commissioning building, supplementary energy consumption, etc. a comparison is drawn between the costs of using a solar water heater in a residential unit with the energy costs of a similar unit equipped with a conventional gas water heater. Given the current price of energy, using a solar water heater in the country will not economical, but considering the global energy prices, this system will have a return on investment after 4.5 years. It also produces 81% less pollution and saves about $21.5 on environmental pollution cleanup.

Keywords: energy supply, new energies, new technologies, buildings

Procedia PDF Downloads 146

Authors: Vijayakumar Kunche

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Waste heat recovery from Pre Heater exhaust gases and Clinker cooler vent gases is now common place in Cement Industry. Most common practice is to use Steam Rankine cycle for heat to power conversion. In this process, waste heat from the flue gas is recovered through a Heat Recovery steam generator where steam is generated and fed to a conventional Steam turbine generator. However steam Rankine cycle tends to have lesser efficiency for smaller power plants with less than 5MW capacity and where the steam temperature at the inlet of the turbine is less than 350 deg C. further a steam Rankine cycle needs treated water and maintenance intensive. These problems can be overcome by using Thermodynamic cycle using Cyclopentane vapour in place of steam. This innovative cycle is best suited for Heat recovery in cement plants and results in best possible heat to power conversion efficiency. This paper discusses about Heat Recovery Power generation using innovative thermal cycle which uses Cyclopentane vapour in place of water- steam. And how this technology has been adopted for a Clinker cooler hot gas from mid-tap.

Keywords: clinker cooler, energy efficiency, organic rankine cycle, waste heat recovery

Procedia PDF Downloads 217

Authors: Daniel Phifer, Anna Prokhodtseva

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DualBeam (FIB-SEM) has long been the technology of choice to sub-sample and characterize materials at site-specific locations which are difficult or impossible to extract by conventional embedding/polishing methods. Whereas Ga based FIB provides excellent resolution and enables precise material removal, the current is usually limited and only allows the extraction of small material biopsies typically ranging from 5-70um wide. Xe Plasma FIB, by contrast, has around 38x more current and can remove more material at the same time to extract significant sized chunks (100-1000um) of materials for further analysis. This increased volume has enabled time-prohibitive investigations like large grain 3D serial sectioning and EBSD and micro-machining for micro-mechanical testing. Investigation of the pore spaces with 3D modeling can determine the relative characteristics of the materials to help design or select properties for best function. Pore spaces can be described with a tortuosity number which is calculated by modules in the 3D analysis software. Xe Plasma FIB technology provides a workflow with sufficient volume to characterize porosity when both large-volume 3D materials characterization and nanometer resolution is required to understand the system.

Keywords: dual-beam, FIB-SEM, porosity, SOFC, solid oxide fuel cell

Procedia PDF Downloads 192

Authors: Min-Kook Park, Deuck Hang Lee, Hyun Mo Yang, Jae Hyun Kim, Kang Su Kim

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Prestressed hollow-core slabs (HCS) are structurally optimized precast units with light-weight hollowed-sections and very economical due to the mass production by a unique production method. They have been thus widely used in the precast concrete constructions in many countries all around the world. It is, however, difficult to provide shear reinforcement in HCS units produced by the extrusion method, and thus all the shear forces should be resisted solely by concrete webs in the HCS units. This means that, for the HCS units, it is very important to estimate the contribution of web concrete to the shear resistance accurately. In design codes, however, the shear strengths for HCS units are estimated by the same equations that are used for typical prestressed concrete members, which were determined from the calibrations to experimental results of conventional prestressed concrete members other than HCS units. In this study, therefore, shear test results of HCS members with a wide range of influential variables were collected, and the shear strength equations in design codes were thoroughly examined by comparing to the experimental results in the shear database of HCS members. Acknowledgement: This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT & Future Planning(NRF-2016R1A2B2010277).

Keywords: hollow-core, web-shear, precast concrete, prestress, capacity

Procedia PDF Downloads 489

Authors: Daniel Nieto, Ramiro Couceiro

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Microfluidic chips have demonstrated their significant application potentials in microbiological processing and chemical reactions, with the goal of developing monolithic and compact chip-sized multifunctional systems. Heat generation and thermal control are critical in some of the biochemical processes. The paper presents a laser direct-write technique for rapid prototyping and manufacturing of microheater chips and its applicability for perfusion cell culture outside a cell incubator. The aim of the microheater is to take the role of conventional incubators for cell culture for facilitating microscopic observation or other online monitoring activities during cell culture and provides portability of cell culture operation. Microheaters (5 mm × 5 mm) have been successfully fabricated on soda-lime glass substrates covered with aluminum layer of thickness 120 nm. Experimental results show that the microheaters exhibit good performance in temperature rise and decay characteristics, with localized heating at targeted spatial domains. These microheaters were suitable for a maximum long-term operation temperature of 120ºC and validated for long-time operation at 37ºC. for 24 hours. Results demonstrated that the physiology of the cultured SW480 adenocarcinoma of the colon cell line on the developed microheater chip was consistent with that of an incubator.

Keywords: laser microfabrication, microheater, bioengineering, cell culture

Procedia PDF Downloads 277

Authors: Gaddafi Sani Shehu, Tankut Yalcınoz, Abdullahi Bala Kunya

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Multilevel inverters such as flying capacitor, diode-clamped, and cascaded H-bridge inverters are very popular particularly in medium and high power applications. This paper focuses on a cascaded H-bridge module using a single direct current (DC) source in order to generate an 11-level output voltage. The noble approach reduces the number of switches and gate drivers, in comparison with a conventional method. The anticipated topology produces more accurate result with an isolation transformer at high switching frequency. Different modulation techniques can be used for the multilevel inverter, but this work features modulation techniques known as selective harmonic elimination (SHE).This modulation approach reduces the number of carriers with reduction in Switching Losses, Total Harmonic Distortion (THD), and thereby increasing Power Quality (PQ). Based on the simulation result obtained, it appears SHE has the ability to eliminate selected harmonics by chopping off the fundamental output component. The performance evaluation of the proposed cascaded multilevel inverter is performed using PSIM simulation package and THD of 0.94% is obtained.

Keywords: cascaded H-bridge multilevel inverter, power quality, selective harmonic elimination

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Authors: Ajay Kumar Choubey, Geeta Agnihotri, C. Sasikumar, Rashmi Dwivedi

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Deep-drawing operations are performed widely in industrial applications. It is very important for efficiency to achieve parts with no or minimum defects. Deep drawn parts are used in high performance, high strength and high reliability applications where tension, stress, load and human safety are critical considerations. Wrinkling is a kind of defect caused by stresses in the flange part of the blank during metal forming operations. To avoid wrinkling appropriate blank-holder pressure/force or drawbead can be applied. Now-a-day computer simulation plays a vital role in the field of manufacturing process. So computer simulation of manufacturing has much advantage over previous conventional process i.e. mass production, good quality of product, fast working etc. In this study, a two dimensional elasto-plastic Finite Element (F.E.) model for Mild Steel material blank has been developed to study the behavior of the flange wrinkling and deep drawing parameters under different Blank-Holder Pressure (B.H.P.). For this, commercially available Finite Element software ANSYS 14 has been used in this study. Simulation results are critically studied and salient conclusions have been drawn.

Keywords: ANSYS, deep drawing, BHP, finite element simulation, wrinkling

Procedia PDF Downloads 438

Authors: Suraka Bhattacharjee, Ranjan Chaudhury

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The interaction between the charge degrees of freedom for itinerant antiferromagnets is investigated in terms of generalized charge stiffness constant corresponding to nearest neighbour t-J model and t1-t2-t3-J model. The low dimensional hole doped antiferromagnets are the well known systems that can be described by the t-J-like models. Accordingly, we have used these models to investigate the fermionic pairing possibilities and the coupling between the itinerant charge degrees of freedom. A detailed comparison between spin and charge couplings highlights that the charge and spin couplings show very similar behaviour in the over-doped region, whereas, they show completely different trends in the lower doping regimes. Moreover, a qualitative equivalence between generalized charge stiffness and effective Coulomb interaction is also established based on the comparisons with other theoretical and experimental results. Thus it is obvious that the enhanced possibility of fermionic pairing is inherent in the reduction of Coulomb repulsion with increase in doping concentration. However, the increased possibility can not give rise to pairing without the presence of any other pair producing mechanism outside the t-J model. Therefore, one can conclude that the t-J-like models themselves solely are not capable of producing conventional momentum-based superconducting pairing on their own.

Keywords: generalized charge stiffness constant, charge coupling, effective Coulomb interaction, t-J-like models, momentum-space pairing

Procedia PDF Downloads 141

Authors: Sai Sudarshan, Harsh Vyas, Riddhiman Sherlekar

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The oil and gas industry has been unwilling to adopt stochastic definition of reserves. Nevertheless, Monte Carlo simulation methods have gained acceptance by engineers, geoscientists and other professionals who want to evaluate prospects or otherwise analyze problems that involve uncertainty. One of the common applications of Monte Carlo simulation is the estimation of recoverable hydrocarbon from a reservoir.Monte Carlo Simulation makes use of random samples of parameters or inputs to explore the behavior of a complex system or process. It finds application whenever one needs to make an estimate, forecast or decision where there is significant uncertainty. First, the project focuses on performing Monte-Carlo Simulation on a given data set using U. S Department of Energy’s MonteCarlo Software, which is a freeware e&p tool. Further, an algorithm for simulation has been developed for MATLAB and program performs simulation by prompting user for input distributions and parameters associated with each distribution (i.e. mean, st.dev, min., max., most likely, etc.). It also prompts user for desired probability for which reserves are to be calculated. The algorithm so developed and tested in MATLAB further finds implementation in Python where existing libraries on statistics and graph plotting have been imported to generate better outcome. With PyQt designer, codes for a simple graphical user interface have also been written. The graph so plotted is then validated with already available results from U.S DOE MonteCarlo Software.

Keywords: simulation, probability, confidence interval, sensitivity analysis

Procedia PDF Downloads 367

Authors: Win Nee Phong, Tau Chuan Ling, Pau Loke Show

Abstract:

From an industrial perspective, the exploitation of microalgae for protein source is of great economical and commercial interest due to numerous attractive characteristics. Nonetheless, the release of protein from microalgae is limited by the multiple layers of the rigid thick cell wall that generally contain a large proportion of cellulose. Thus an efficient cell disruption process is required to rupture the cell wall. The conventional downstream processing methods which typically involve several unit operational steps such as disruption, isolation, extraction, concentration and purification are energy-intensive and costly. To reduce the overall cost and establish a feasible technology for the success of the large-scale production, microalgal industry today demands a more cost-effective and eco-friendly technique in downstream processing. One of the main challenges to extract the proteins from microalgae is the presence of rigid cell wall. This study aims to provide some guidance on the selection of the efficient solvent to facilitate the proteins released during the cell disruption process. The effects of solvent types such as methanol, ethanol, 1-propanol and water in rupturing the microalgae cell wall were studied. It is interesting to know that water is the most effective solvent to recover proteins from microalgae and the cost is cheapest among all other solvents.

Keywords: green, microalgae, protein, solvents

Procedia PDF Downloads 239

Authors: Ugur Buyuk, Sevda Engin

Abstract:

Among the various alloy systems being considered as lead-free solder candidates, Sn-Ag-Cu alloys have been recognized as the most promising because of their excellent reliability and compatibility with current components. Thus, Sn-Ag-Cu alloys have recently attracted considerable attention and have been proposed by the Japanese, the EU and the US consortiums to replace conventional Sn-Pb eutectic solder. However, many problems or unknown characteristics of the Sn-Ag-Cu alloy system such as the best composition, the large undercooling in solidification, and the formation of large intermetallics still exist. It is expected that the addition of some solidification nuclei for Sn-Ag-Cu alloys will refine the solidification microstructure and will suppress undercooling.In the present work, the effects of the fourth elements, i.e., Zn, Ni, Bi, In and Co, on microstructural and mechanical properties of Sn-3.5Ag-0.9Cu lead-free solder were investigated. Sn-3.5Ag-0.9Cu-0.5X (X= Zn, Ni, Bi, In, Co (wt.)) alloys were prepared in a graphite crucible under vacuum atmosphere. The samples were directionally solidified upward at a constant temperature gradient and growth rates by using a Bridgman type directional solidification furnace. The microstructure, microhardness and ultimate tensile strength of alloys were measured. The effects of fourth elements on the microstructure and mechanical properties of Sn–Ag-Cu eutectic alloys were investigated. The results obtained in the present work were compared with the previous experimental results.

Keywords: lead-free solders, microhardness, microstructure, tensile strength

Procedia PDF Downloads 401

Authors: D. S. Naumann, B. J. Evans, O. Hassan

Abstract:

This paper outlines the development of an automated aerodynamic optimisation algorithm using a novel method of parameterising a computational mesh by employing user–defined control nodes. The shape boundary movement is coupled to the movement of the novel concept of the control nodes via a quasi-1D-linear deformation. Additionally, a second order smoothing step has been integrated to act on the boundary during the mesh movement based on the change in its second derivative. This allows for both linear and non-linear shape transformations dependent on the preference of the user. The domain mesh movement is then coupled to the shape boundary movement via a Delaunay graph mapping. A Modified Cuckoo Search (MCS) algorithm is used for optimisation within the prescribed design space defined by the allowed range of control node displacement. A finite volume compressible NavierStokes solver is used for aerodynamic modelling to predict aerodynamic design fitness. The resulting coupled algorithm is applied to a range of test cases in two dimensions including the design of a subsonic, transonic and supersonic intake and the optimisation approach is compared with more conventional optimisation strategies. Ultimately, the algorithm is tested on a three dimensional wing optimisation case.

Keywords: mesh movement, aerodynamic shape optimization, cuckoo search, shape parameterisation

Procedia PDF Downloads 318

Authors: Anton G. Akulichev, Avinash Tiwari, Ben Alcock, Andreas Echtermeyer

Abstract:

Low temperatures are known to pose a major threat for polymers; many are prone to excessive stiffness or even brittleness. There is a technology gap between the properties of existing elastomeric sealing materials and the properties needed for service in extremely cold regions. Moreover, some aspects of low temperature behaviour of rubber are not thoroughly studied and understood. The paper presents results of laboratory testing of a conventional oilfield HNBR (hydrogenated nitrile butadiene rubber) elastomer at low climatic temperatures above and below its glass transition point, as well as the performance of some filled HNBR formulations. Particular emphasis in the experiments is put on rubber viscoelastic characteristics studied by Dynamic Mechanical Analysis (DMA) and quasi-static mechanical testing results at low temperatures. As demonstrated by the stress relaxation and DMA experiments the transition region near Tg of the studied compound has the most striking features, like rapid stress relaxation, as compared to the glassy and rubbery plateau. In addition the quasi-static experiments show that molecular movement below Tg is not completely frozen, but rather evident and manifested in a certain stress decay as well. The effect of temperature and filler additions on typical mechanical and other properties of the materials is also discussed.

Keywords: characterization, filled elastomers, HNBR, low temperature

Procedia PDF Downloads 299

Authors: Syed Khurram Mahmud, Athar Naveed, Shoaib Arif

Abstract:

Beamforming is a signal processing technique extensively utilized in wireless communications and radars for desired signal intensification and interference signal minimization through spatial selectivity. In this paper, we present a method for calculation of optimal weight vectors for smart antenna array, to achieve a directive pattern during transmission and selective reception in interference prone environment. In proposed scheme, Mutual Information (MI) extrema are evaluated through an energy constrained objective function, which is based on a-priori information of interference source and desired array factor. Signal to Interference plus Noise Ratio (SINR) performance is evaluated for both transmission and reception. In our scheme, MI is presented as an index to identify trade-off between information gain, SINR, illumination time and spatial selectivity in an energy constrained optimization problem. The employed method yields lesser computational complexity, which is presented through comparative analysis with conventional methods in vogue. MI based beamforming offers enhancement of signal integrity in degraded environment while reducing computational intricacy and correlating key performance indicators.

Keywords: beamforming, interference, mutual information, wireless communications

Procedia PDF Downloads 263

Authors: Junkyeong Kim, Jooyoung Park, Aoqi Zhang, Seunghee Park

Abstract:

The tensile force of Pre-Stressed Concrete (PSC) girder is the most important factor for evaluating the performance of PSC girder bridges. To measure the tensile force of PSC girder, several NDT methods were studied. However, conventional NDT method cannot be applied to the real-size PSC girder because the PS tendons could not be approached. To measure the tensile force of real-size PSC girder, this study proposed embedded EM sensor based tensile force estimation method. The embedded EM sensor could be installed inside of PSC girder as a sheath joint before the concrete casting. After curing process, the PS tendons were installed, and the tensile force was induced step by step using hydraulic jacking machine. The B-H loop was measured using embedded EM sensor at each tensile force steps and to compare with actual tensile force, the load cell was installed at each end of girder. The magnetization energy loss, that is the closed area of B-H loop, was decreased according to the increase of tensile force with regular pattern. Thus, the tensile force could be estimated by the tracking the change of magnetization energy loss of PS tendons. Through the experimental result, the proposed method can be used to estimate the tensile force of the in-situ real-size PSC girder bridge.

Keywords: tensile force estimation, embedded EM sensor, magnetization energy loss, PSC girder

Procedia PDF Downloads 320