Search results for: short beam
2614 Effect of the Concrete Cover on the Bond Strength of the FRP Wrapped and Non-Wrapped Reinforced Concrete Beam with Lap Splice under Uni-Direction Cyclic Loading
Authors: Rayed Alyousef, Tim Topper, Adil Al-Mayah
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Many of the reinforced concrete structures subject to cyclic load constructed before the modern bond and fatigue design code. One of the main issue face on exists structure is the bond strength of the longitudinal steel bar and the surrounding concrete. A lap splice is a common connection method to transfer the force between the steel rebar in a reinforced concrete member. Usually, the lap splice is the weak connection on the bond strength. Fatigue flexural loading imposes severe demands on the strength and ductility of the lap splice region in reinforced concrete structures and can lead to a brittle and sudden failure of the member. This paper investigates the effect of different concrete covers on the fatigue bond strength of reinforcing concrete beams containing a lap splice under a fatigue loads. It includes tests of thirty-seven beams divided into three groups. Each group has beams with 30 mm and 50 mm clear side and bottom concrete covers. The variables that were addressed where the concrete cover, the presence or absence of CFRP or GFRP sheet wrapping, the type of loading (monotonic or fatigue) and the fatigue load ranges. The test results showed that an increase in the concrete cover led to an increase in the bond strength under both monotonic and fatigue loading for both the unwrapped and wrapped beams. Also, the FRP sheets increased both the fatigue strength and the ductility for both the 30 mm and the 50 mm concrete covers.Keywords: bond strength, fatigue, Lap splice, FRp wrapping
Procedia PDF Downloads 4902613 Adoption of Lean Thinking and Service Improvement for Care Home Service
Authors: Chuang-Chun Chiou
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Ageing population is a global trend; therefore the need of care service has been increasing dramatically. There are three basic forms of service delivered to the elderly: institution, community, and home. Particularly, the institutional service can be seen as an extension of medical service. The nursing home or so-called care home which is equipped with professional staff and facilities can provide a variety of service including rehabilitation service, short-term care, and long term care. Similar to hospital and other health care service, care home service do need to provide quality and cost-effective service to satisfy the dwellers. The main purpose of this paper is to show how lean thinking and service innovation can be applied to care home operation. The issues and key factors of implementing lean practice are discussed.Keywords: lean, service improvement, SERVQUAL, care home service
Procedia PDF Downloads 6072612 Tunnelling Concepts in Overstressed Weak Rocks
Authors: Entfellner Manuel, Wannenmacher Helmut, Reisenbauer Josef, Schubert Wulf
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When tunnelling in overstressed weak rocks ("squeezing ground"), two basic design approaches are available: the resistance principle, and the yielding principle. The resistance principle relies on rigid support systems to withstand the ground pressure. Alternatively, the yielding principle prioritizes controlled deformation, allowing the ground to deform without compromising tunnel integrity. This paper highlights the beneficial factors of the yielding principle for conventionally excavated tunnels in overstressed weak rocks. Especially the application of a ductile shotcrete lining with yielding elements is analysed in detail. Construction costs, safety, short- and long-term stabilities are discussed.Keywords: squeezing ground, yielding principle, yielding element, conventional tunneling
Procedia PDF Downloads 732611 Influence of Concrete Cracking in the Tensile Strength of Cast-in Headed Anchors
Authors: W. Nataniel, B. Lima, J. Manoel, M. P. Filho, H. Marcos, Oliveira Mauricio, P. Ferreira
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Headed reinforcement bars are increasingly used for anchorage in concrete structures. Applications include connections in composite steel-concrete structures, such as beam-column joints, in several strengthening situations as well as in more traditional uses in cast-in-place and precast structural systems. This paper investigates the reduction in the ultimate tensile capacity of embedded cast-in headed anchors due to concrete cracking. A series of nine laboratory tests are carried out to evaluate the influence of cracking on the concrete breakout strength in tension. The experimental results show that cracking affects both the resistance and load-slip response of the headed bar anchors. The strengths measured in these tests are compared to theoretical resistances calculated following the recommendations presented by fib Bulletin no. 58 (2011), ETAG 001 (2010) and ACI 318 (2014). The influences of parameters such as the effective embedment depth (hef), bar diameter (ds), and the concrete compressive strength (fc) are analysed and discussed. The theoretical recommendations are shown to be over-conservative for both embedment depths and were, in general, inaccurate in comparison to the experimental trends. The ACI 318 (2014) was the design code which presented the best performance regarding to the predictions of the ultimate load, with an average of 1.42 for the ratio between the experimental and estimated strengths, standard deviation of 0.36, and coefficient of variation equal to 0.25.Keywords: cast-in headed anchors, concrete cone failure, uncracked concrete, cracked concrete
Procedia PDF Downloads 2062610 The Effect of Damper Attachment on Tennis Racket Vibration: A Simulation Study
Authors: Kuangyou B. Cheng
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Tennis is among the most popular sports worldwide. During ball-racket impact, substantial vibration transmitted to the hand/arm may be the cause of “tennis elbow”. Although it is common for athletes to attach a “vibration damper” to the spring-bed, the effect remains unclear. To avoid subjective factors and errors in data recording, the effect of damper attachment on racket handle end vibration was investigated with computer simulation. The tennis racket was modeled as a beam with free-free ends (similar to loosely holding the racket). Finite difference method with 40 segments was used to simulate ball-racket impact response. The effect of attaching a damper was modeled as having a segment with increased mass. It was found that the damper has the largest effect when installed at the spring-bed center. However, this is not a practical location due to interference with ball-racket impact. Vibration amplitude changed very slightly when the damper was near the top or bottom of the spring-bed. The damper works only slightly better at the bottom than at the top of the spring-bed. In addition, heavier dampers work better than lighter ones. These simulation results were comparable with experimental recordings in which the selection of damper locations was restricted by ball impact locations. It was concluded that mathematical model simulations were able to objectively investigate the effect of damper attachment on racket vibration. In addition, with very slight difference in grip end vibration amplitude when the damper was attached at the top or bottom of the spring-bed, whether the effect can really be felt by athletes is questionable.Keywords: finite difference, impact, modeling, vibration amplitude
Procedia PDF Downloads 2622609 Evaluating Forecasting Strategies for Day-Ahead Electricity Prices: Insights From the Russia-Ukraine Crisis
Authors: Alexandra Papagianni, George Filis, Panagiotis Papadopoulos
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The liberalization of the energy market and the increasing penetration of fluctuating renewables (e.g., wind and solar power) have heightened the importance of the spot market for ensuring efficient electricity supply. This is further emphasized by the EU’s goal of achieving net-zero emissions by 2050. The day-ahead market (DAM) plays a key role in European energy trading, accounting for 80-90% of spot transactions and providing critical insights for next-day pricing. Therefore, short-term electricity price forecasting (EPF) within the DAM is crucial for market participants to make informed decisions and improve their market positioning. Existing literature highlights out-of-sample performance as a key factor in assessing EPF accuracy, with influencing factors such as predictors, forecast horizon, model selection, and strategy. Several studies indicate that electricity demand is a primary price determinant, while renewable energy sources (RES) like wind and solar significantly impact price dynamics, often lowering prices. Additionally, incorporating data from neighboring countries, due to market coupling, further improves forecast accuracy. Most studies predict up to 24 steps ahead using hourly data, while some extend forecasts using higher-frequency data (e.g., half-hourly or quarter-hourly). Short-term EPF methods fall into two main categories: statistical and computational intelligence (CI) methods, with hybrid models combining both. While many studies use advanced statistical methods, particularly through different versions of traditional AR-type models, others apply computational techniques such as artificial neural networks (ANNs) and support vector machines (SVMs). Recent research combines multiple methods to enhance forecasting performance. Despite extensive research on EPF accuracy, a gap remains in understanding how forecasting strategy affects prediction outcomes. While iterated strategies are commonly used, they are often chosen without justification. This paper contributes by examining whether the choice of forecasting strategy impacts the quality of day-ahead price predictions, especially for multi-step forecasts. We evaluate both iterated and direct methods, exploring alternative ways of conducting iterated forecasts on benchmark and state-of-the-art forecasting frameworks. The goal is to assess whether these factors should be considered by end-users to improve forecast quality. We focus on the Greek DAM using data from July 1, 2021, to March 31, 2022. This period is chosen due to significant price volatility in Greece, driven by its dependence on natural gas and limited interconnection capacity with larger European grids. The analysis covers two phases: pre-conflict (January 1, 2022, to February 23, 2022) and post-conflict (February 24, 2022, to March 31, 2022), following the Russian-Ukraine conflict that initiated an energy crisis. We use the mean absolute percentage error (MAPE) and symmetric mean absolute percentage error (sMAPE) for evaluation, as well as the Direction of Change (DoC) measure to assess the accuracy of price movement predictions. Our findings suggest that forecasters need to apply all strategies across different horizons and models. Different strategies may be required for different horizons to optimize both accuracy and directional predictions, ensuring more reliable forecasts.Keywords: short-term electricity price forecast, forecast strategies, forecast horizons, recursive strategy, direct strategy
Procedia PDF Downloads 112608 Women Right in Islam and Misconceptions: A Critical Study
Authors: Abubakar Ibrahim Usman, Mustapha Halilu
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The provisions of rights to women in Islam have generated and are creating a tense and serious debate among Muslims and non-Muslims alike. The Muslims are arguing that Islam provides right to Womenfolk, but their actions, cultural/traditional practices, and treatment reveal otherwise, Non-Muslims, on the other hand, held a different view, saying that Islam has never made such provision. One may not blame their misconception, due to the wide spectrum of treatment given to women in many Muslim societies, which generated, fueled and geared the misconceptions and ceaseless barrage of sensational articles, movies and negative portrayal of Islam today. It has to put in our minds, many actions and Crimes of some Muslims (Who are mostly minority) did not represent the teachings and precepts of Islam, just like one cannot put blame on the parents of a child whose actions fall short of his home background.Keywords: Islam, women rights, cultural practices, religion
Procedia PDF Downloads 4442607 Investigating the Successes of in vitro Embryogenesis
Authors: Zelikha Labbani
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The in vitro isolated microspore culture is the most powerful androgenic pathway to produce doubled haploid plants in the short time. To deviate a microspore toward embryogenesis, a number of factors, different for each species, must concur at the same time and place. Once induced, the microspore undergoes numerous changes at different levels, from overall morphology to gene expression. Induction of microspore embryogenesis not only implies the expression of an embryogenic program, but also a stress-related cellular response and a repression of the gametophytic program to revert the microspore to a totipotent status. As haploid single cells, microspore became a strategy to achieve various objectives particularly in genetic engineering. In this communication we would show the most recent advances in the producing haploid embryos via in vitro isolated microspore culture.Keywords: in vitro isolated microspore culture, success, haploid cells, bioinformatics, biomedicine
Procedia PDF Downloads 4762606 Writing Style in a Thousand Splendid Suns
Authors: Maroof Sakhi
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This article studies writing style in A Thousand Splendid Suns. It mainly discusses code-switching and usage of Persian words in the novel. Hosseini mainly writes in English; however, constantly he applies Persian words, phrases and syntax. Code-switching is used for different purposes in A Thousand Splendid Suns. It gives a voice to a character from Afghanistan. It is also used to mark a difference between the American and Afghanistan cultures and languages. Furthermore, representation of Persian language can be interpreted as valorization of the author’s mother tongue. In short, the writing style in A Thousand Splendid Suns represents Hosseini’s identity, culture and linguistic background.Keywords: code-switching, hybridity, identity, linguistic background, Persian literature
Procedia PDF Downloads 992605 Residual Power Series Method for System of Volterra Integro-Differential Equations
Authors: Zuhier Altawallbeh
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This paper investigates the approximate analytical solutions of general form of Volterra integro-differential equations system by using the residual power series method (for short RPSM). The proposed method produces the solutions in terms of convergent series requires no linearization or small perturbation and reproduces the exact solution when the solution is polynomial. Some examples are given to demonstrate the simplicity and efficiency of the proposed method. Comparisons with the Laplace decomposition algorithm verify that the new method is very effective and convenient for solving system of pantograph equations.Keywords: integro-differential equation, pantograph equations, system of initial value problems, residual power series method
Procedia PDF Downloads 4192604 Perception, Awareness and Attitude of Muslim Academicians on Islamic Banking Products in Kano State of Nigeria
Authors: Muhammad Abdullahi Mago
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Islamic Banking began in Nigeria last three years and the sector has shown the sign of bright future for the sector and the Nigerian economy, within this very short time it is important to know the perception of the customers particularly learned or educated individuals for immediate evaluation and adjustment. This study investigates into the perception, awareness and attitudes of the academicians in the most populous state/place in Nigeria with more than 90% muslims, and the results has shown a relatively low levels results in all the variables of the study.The study recommends aggressive marketing strategy for the Banks operating within the sector.Keywords: Islamic Banking Products, Islamic Financial Products, academicians, Islamic finance industry, perception, awareness and attitude
Procedia PDF Downloads 4432603 Practical Aspects Pertaining to the Selection of Size and Location of Source Substations in an Oil Field
Authors: Yadavalli Venkata Sridhar
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Finalization of Substation sizing and location is an important task to be carried out by electrical designers in an oil field. Practical issues influence the selection of size and location of the source substations that feed multiple production facilities are listed. Importance of selection of appropriately rated short circuit level for 11KV switchboards and constraints pertaining to availability of manufacturers are highlighted. Without being lost in the research of absolute optimum solution, under time constraints, the importance of practical approach is brought out. Focus on identifying near optimum solutions by process of elimination of unfeasible substation locations with the support of cost figures, is emphasized through a case study.Keywords: substation, size, location, oil field
Procedia PDF Downloads 6642602 Investigation into the Homoepitaxy of AlGaN/GaN Heterostructure via Molecular Beam Epitaxy
Authors: Jiajia Yao, Guanlin Wu, Fang Liu, Junshuai Xue, Yue Hao
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As the production process of self-standing GaN substrates evolves, the commercialization of low dislocation density, large-scale, semi-insulating self-standing GaN substrates is gradually becoming a reality. This advancement has given rise to increased interest in GaN materials' homoepitaxial technology. However, at the homoepitaxial interface, there are considerable concentrations of impurity elements, including C, Si, and O, which generate parasitic leakage channels at the re-growth junction. This phenomenon results in leaked HEMTs that prove difficult to switch off, rendering them effectively non-functional. The emergence of leakage channels can also degrade the high-frequency properties and lower the power devices' breakdown voltage. In this study, the uniform epitaxy of AlGaN/GaN heterojunction with high electron mobility was accomplished through the surface treatment of the GaN substrates prior to growth and the design of the AlN isolation layer structure. By employing a procedure combining gallium atom in-situ cleaning and plasma nitridation, the C and O impurity concentrations at the homoepitaxial interface were diminished to the scale of 10¹⁷ cm-³. Additionally, the 1.5 nm nitrogen-rich AlN isolation layer successfully prevented the diffusion of Si impurities into the GaN channel layer. The result was an AlGaN/GaN heterojunction with an electron mobility of 1552 cm²/Vs and an electron density of 1.1 × 10¹³ cm-² at room temperature, obtained on a Fe-doped semi-insulating GaN substrate.Keywords: MBE, AlGaN/GaN, homogenerous epitaxy, HEMT
Procedia PDF Downloads 712601 Ottoman Marches Composed by European Musicians
Authors: Selcen Özyurt Ulutaş
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March as a musical form in Ottoman Music has started after Sultan II. Mahmud. Owing to the modernization process on Ottoman Empire, marches had accepted and embraced by the sultanate in a short period of time. The reasons behind sultans favor against marches that is actually a European Music form is closely related to attribute meanings to marches. After Sultan II. Mahmud, marches became a symbol of westernization and became a symbol of sultanate. After that period besides sultans also princes started to compose marches. The presentation includes the demonstration of the marches classification in achieves to be able to give information on the composers of those marches. Through that process, this study aims to show attributed meanings to those marches and what those marches represent.Keywords: Ottoman marches, music, Europe, European musicians
Procedia PDF Downloads 3192600 Suspended Nickel Oxide Nano-Beam and Its Heterostructure Device for Gas Sensing
Authors: Kusuma Urs M. B., Navakant Bhat, Vinayak B. Kamble
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Metal oxide semiconductors (MOS) are known to be excellent candidates for solid-state gas sensor devices. However, in spite of high sensitivities, their high operating temperatures and lack of selectivity is a big concern limiting their practical applications. A lot of research has been devoted so far to enhance their sensitivity and selectivity, often empirically. Some of the promising routes to achieve the same are reducing dimensionality and formation of heterostructures. These heterostructures offer improved sensitivity, selectivity even at relatively low operating temperatures compared to bare metal oxides. Thus, a combination of n-type and p-type metal oxides leads to the formation of p-n junction at the interface resulting in the diffusion of the carriers across the barrier along with the surface adsorption. In order to achieve this and to study their sensing mechanism, we have designed and lithographically fabricated a suspended nanobeam of NiO, which is a p-type semiconductor. The response of the same has been studied for various gases and is found to exhibit selective response towards hydrogen gas at room temperature. Further, the same has been radially coated with TiO₂ shell of varying thicknesses, in order to study the effect of radial p-n junction thus formed. Subsequently, efforts have been made to study the effect of shell thickness on the space charge region and to shed some light on the basic mechanism involved in gas sensing of MOS sensors.Keywords: gas sensing, heterostructure, metal oxide semiconductor, space charge region
Procedia PDF Downloads 1332599 Thermodynamic Study of Homo-Pairs in Molten Cd-Me, (Me=Ga,in) Binary Systems
Authors: Yisau Adelaja Odusote, Olakanmi Felix Akinto
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The associative tendency between like atoms in molten Cd-Ga and Cd-In alloy systems has been studied by using the Quasi-Chemical Approximation Model (QCAM). The concentration dependence of the microscopic functions (the concentration-concentration fluctuations in the long-wavelength limits, Scc(0), the chemical short-range order (CSRO) parameter α1 as well as the chemical diffusion) and the mixing properties as the free energy of mixing, GM, enthalpy of mixing and entropy of mixing of the two molten alloys have been determined. Thermodynamic properties of both systems deviate positively from Raoult's law, while the systems are characterized by positive interaction energy. The role of atomic size ratio on the alloying properties was discussed.Keywords: homo-pairs, interchange energy, enthalpy, entropy, Cd-Ga, Cd-In
Procedia PDF Downloads 4372598 Big Data Strategy for Telco: Network Transformation
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Big data has the potential to improve the quality of services; enable infrastructure that businesses depend on to adapt continually and efficiently; improve the performance of employees; help organizations better understand customers; and reduce liability risks. Analytics and marketing models of fixed and mobile operators are falling short in combating churn and declining revenue per user. Big Data presents new method to reverse the way and improve profitability. The benefits of Big Data and next-generation network, however, are more exorbitant than improved customer relationship management. Next generation of networks are in a prime position to monetize rich supplies of customer information—while being mindful of legal and privacy issues. As data assets are transformed into new revenue streams will become integral to high performance.Keywords: big data, next generation networks, network transformation, strategy
Procedia PDF Downloads 3612597 Developing a Comprehensive Green Building Rating System Tailored for Nigeria: Analyzing International Sustainable Rating Systems to Create Environmentally Responsible Standards for the Nigerian Construction Industry and Built Environment
Authors: Azeez Balogun
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Inexperienced building score practices are continually evolving and vary across areas. Yet, a few middle ideas stay steady, such as website selection, design, energy efficiency, water and material conservation, indoor environmental great, operational optimization, and waste discount. The essence of green building lies inside the optimization of 1 or more of those standards. This paper conducts a comparative analysis of 7 extensively recognized sustainable score structures—BREEAM, CASBEE, green GLOBES, inexperienced superstar, HK-BEAM, IGBC green homes, and LEED—based totally on the perceptions and opinions of stakeholders in Nigeria certified in green constructing rating systems. The purpose is to pick out and adopt an appropriate green building rating device for Nigeria. Numerous components of those systems had been tested to determine the high-quality health of the Nigerian built environment. The findings imply that LEED, the important machine within the USA and Canada, is the most suitable for Nigeria due to its sturdy basis, extensive funding, and confirmed blessings. LEED obtained the highest rating of eighty out of one hundred points on this assessment.Keywords: structure, built surroundings, inexperienced building score gadget, Nigeria Inexperienced Constructing Council, sustainability
Procedia PDF Downloads 312596 Performance Evaluation of the Classic seq2seq Model versus a Proposed Semi-supervised Long Short-Term Memory Autoencoder for Time Series Data Forecasting
Authors: Aswathi Thrivikraman, S. Advaith
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The study is aimed at designing encoders for deciphering intricacies in time series data by redescribing the dynamics operating on a lower-dimensional manifold. A semi-supervised LSTM autoencoder is devised and investigated to see if the latent representation of the time series data can better forecast the data. End-to-end training of the LSTM autoencoder, together with another LSTM network that is connected to the latent space, forces the hidden states of the encoder to represent the most meaningful latent variables relevant for forecasting. Furthermore, the study compares the predictions with those of a traditional seq2seq model.Keywords: LSTM, autoencoder, forecasting, seq2seq model
Procedia PDF Downloads 1572595 A New Method Presentation for Locating Fault in Power Distribution Feeders Considering DG
Authors: Rahman Dashti, Ehsan Gord
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In this paper, an improved impedance based fault location method is proposed. In this method, online fault locating is performed using voltage and current information at the beginning of the feeder. Determining precise fault location in a short time increases reliability and efficiency of the system. The proposed method utilizes information about main component of voltage and current at the beginning of the feeder and distributed generation unit (DGU) in order to precisely locate different faults in acceptable time. To evaluate precision and accuracy of the proposed method, a 13-node is simulated and tested using MATLAB.Keywords: distribution network, fault section determination, distributed generation units, distribution protection equipment
Procedia PDF Downloads 4042594 Sentiment Analysis of Social Media on the Cryptocurrency Price
Authors: Tarek Sadraoui, Ahlem Nasr Othman
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Our research deal with studying and testing the effects of social media on the cryptocurrency price during the period 2020-2023. The rise of the phenomena of cryptocurrency in the world raises questions about the importance of sentiment analysis of social media on the price of the cryptocurrency. Using panel data, we show that the positive and negative twits have a positive and statistically significant impact on the price of the cryptocurrency, and neutral twits have exerted a negative and significant effect on the cryptocurrency price. Specifically, we determine the causal relationship, short-term and long-term relationship with ARDL approach between the cryptocurrency price and social media using the Granger causality test.Keywords: social media, Twitter, Google trend, panel, cryptocurrency
Procedia PDF Downloads 1182593 Proactive Approach to Innovation Management
Authors: Andrus Pedai, Igor Astrov
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The focus of this paper is to compare common approaches for Systems of Innovation (SI) and identify proactive alternatives for driving the innovation. Proactive approaches will also consider short and medium term perspectives with developments in the field of Computer Technology and Artificial Intelligence. Concerning computer technology and large connected information systems, it is reasonable to predict that during current or the next century, intelligence and innovation will be separated from the constraints of human-driven management. After this happens, humans will no longer be driving the innovation and there is possibility that SI for new intelligent systems will set its own targets and exclude humans. Over long time scale, these developments could result in a scenario, which will lead to the development of larger, cross galactic (universal) proactive SI and Intelligence.Keywords: artificial intelligence, DARPA, Moore’s law, proactive innovation, singularity, systems of innovation
Procedia PDF Downloads 4802592 Optimization of Highly Oriented Pyrolytic Graphite Crystals for Neutron Optics
Authors: Hao Qu, Xiang Liu, Michael Crosby, Brian Kozak, Andreas K. Freund
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The outstanding performance of highly oriented pyrolytic graphite (HOPG) as an optical element for neutron beam conditioning is unequaled by any other crystalline material in the applications of monochromator, analyzer, and filter. This superiority stems from the favorable nuclear properties of carbon (small absorption and incoherent scattering cross-sections, big coherent scattering length) and the specific crystalline structure (small thermal diffuse scattering cross-section, layered crystal structure). The real crystal defect structure revealed by imaging techniques is correlated with the parameters used in the mosaic model (mosaic spread, mosaic block size, uniformity). The diffraction properties (rocking curve width as determined by both the intrinsic mosaic spread and the diffraction process, peak and integrated reflectivity, filter transmission) as a function of neutron wavelength or energy can be predicted with high accuracy and reliability by diffraction theory using empirical primary extinction coefficients extracted from a great amount of existing experimental data. The results of these calculations are given as graphs and tables permitting to optimize HOPG characteristics (mosaic spread, thickness, curvature) for any given experimental situation.Keywords: neutron optics, pyrolytic graphite, mosaic spread, neutron scattering, monochromator, analyzer
Procedia PDF Downloads 1432591 A Study on Evaluation for Performance Verification of Ni-63 Radioisotope Betavoltaic Battery
Authors: Youngmok Yun, Bosung Kim, Sungho Lee, Kyeongsu Jeon, Hyunwook Hwangbo, Byounggun Choi
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A betavoltaic battery converts nuclear energy released as beta particles (β-) directly into electrical energy. Betavoltaic cells are analogous to photovoltaic cells. The beta particle’s kinetic energy enters a p-n junction and creates electron-hole pairs. Subsequently, the built-in potential of the p-n junction accelerates the electrons and ions to their respective collectors. The major challenges are electrical conversion efficiencies and exact evaluation. In this study, the performance of betavoltaic battery was evaluated. The betavoltaic cell was evaluated in the same condition as radiation from radioactive isotope using by FE-SEM(field emission scanning electron microscope). The average energy of the radiation emitted from the Ni-63 radioisotope is 17.42 keV. FE-SEM is capable of emitting an electron beam of 1-30keV. Therefore, it is possible to evaluate betavoltaic cell without radioactive isotopes. The betavoltaic battery consists of radioisotope that is physically connected on the surface of Si-based PN diode. The performance of betavoltaic battery can be estimated by the efficiency of PN diode unit cell. The current generated by scanning electron microscope with fixed accelerating voltage (17keV) was measured by using faraday cup. Electrical characterization of the p-n junction diode was performed by using Nano Probe Work Station and I-V measurement system. The output value of the betavoltaic cells developed by this research team was 0.162 μw/cm2 and the efficiency was 1.14%.Keywords: betavoltaic, nuclear, battery, Ni-63, radio-isotope
Procedia PDF Downloads 2592590 Desert Houses of the Past: Green Buildings of Today
Authors: Baharak Shakeri, Seyed Hashem Hosseini
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The weather in deserts is hot and dry in summers, and cold and dry in winters, and difference of temperature of nights and days sometimes reaches to 28°C. People of deserts have reached some solutions to cope with this climatic condition and to decrease its annoying features. Among these solutions are: constructing houses adjacent to each other, making tall walls, using mud brick and thatch cover, constructing domical arches, cellar, and wind catcher, which are together the devices to control the adversity of hot weather in summers and cold weather in winters. Using these solutions, the people of deserts have succeeded to make the best use with the least energy consumption, and to minimize the damage on the nature and environment, and in short, they are friends of the nature, which is a step toward the objectives of green buildings.Keywords: desert house, green building, Iran, nature
Procedia PDF Downloads 3392589 Studies on the Feasibility of Cow Dung as a Non-Conventional Energy Source
Authors: Raj Kumar Rajak, Bharat Mishra
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Bio-batteries represent an entirely new long-term, reasonable, reachable and ecofriendly approach to produce sustainable energy. In the present experimental work, we have studied the effect of generation of power by bio-battery using different electrode pairs. The tests show that it is possible to generate electricity using cow dung as an electrolyte. C-Mg electrode pair shows maximum voltage and SCC (Short Circuit Current) while C-Zn electrode pair shows less OCV (Open Circuit Voltage) and SCC. We have chosen C-Zn electrodes because Mg electrodes are not economical. By the studies of different electrodes and cow dung, it is found that C-Zn electrode battery is more suitable. This result shows that the bio-batteries have the potency to full fill the need of electricity demand for lower energy equipment.Keywords: bio-batteries, electricity, cow-dung, electrodes, non-conventional
Procedia PDF Downloads 2052588 A Connected Structure of All-Optical Logic Gate “NOT-AND”
Authors: Roumaissa Derdour, Lebbal Mohamed Redha
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We present a study of the transmission of the all-optical logic gate using a structure connected with a triangular photonic crystal lattice that is improved. The proposed logic gate consists of a photonic crystal nano-resonator formed by changing the size of the air holes. In addition to the simplicity, the response time is very short, and the designed nano-resonator increases the bit rate of the logic gate. The two-dimensional finite difference time domain (2DFDTD) method is used to simulate the structure; the transmission obtained is about 98% with very negligible losses. The proposed photonic crystal AND logic gate is widely used in future integrated optical microelectronics.Keywords: logic gates, photonic crystals, optical integrated circuits, resonant cavities
Procedia PDF Downloads 1002587 Gradient Index Metalens for WLAN Applications
Authors: Akram Boubakri, Fethi Choubeni, Tan Hoa Vuong, Jacques David
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The control of electromagnetic waves is a key aim of several researches over the past decade. In this regard, Metamaterials have shown a strong ability to manipulate the electromagnetic waves on a subwavelength scales thanks to its unconventional properties that are not available in natural materials such as negative refraction index, super imaging and invisibility cloaking. Metalenses were used to avoid some drawbacks presented by conventional lenses since focusing with conventional lenses suffered from the limited resolution because they were only able to focus the propagating wave component. Nevertheless, Metalenses were able to go beyond the diffraction limit and enhance the resolution not only by collecting the propagating waves but also by restoring the amplitude of evanescent waves that decay rapidly when going far from the source and that contains the finest details of the image. Metasurfaces have many mechanical advantages over three-dimensional metamaterial structures especially the ease of fabrication and a smaller required volume. Those structures have been widely used for antenna performance improvement and to build flat metalenses. In this work, we showed that a well-designed metasurface lens operating at the frequency of 5.9GHz, has efficiently enhanced the radiation characteristics of a patch antenna and can be used for WLAN applications (IEEE 802.11 a). The proposed metasurface lens is built with a geometrically modified unit cells which lead to a change in the response of the lens at different position and allow the control of the wavefront beam of the incident wave thanks to the gradient refractive index.Keywords: focusing, gradient index, metasurface, metalens, WLAN Applications
Procedia PDF Downloads 2562586 Tunable Control of Therapeutics Release from the Nanochannel Delivery System (nDS)
Authors: Thomas Geninatti, Bruno Giacomo, Alessandro Grattoni
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Nanofluidic devices have been investigated for over a decade as promising platforms for the controlled release of therapeutics. The nanochannel drug delivery system (nDS), a membrane fabricated with high precision silicon techniques, capable of zero-order release of drugs by exploiting diffusion transport at the nanoscale originated from the interactions between molecules with nanochannel surfaces, showed the flexibility of the sustained release in vitro and in vivo, over periods of time ranging from weeks to months. To improve the implantable bio nanotechnology, in order to create a system that possesses the key features for achieve the suitable release of therapeutics, the next generation of nDS has been created. Platinum electrodes are integrated by e-beam deposition onto both surfaces of the membrane allowing low voltage (<2 V) and active temporal control of drug release through modulation of electrostatic potentials at the inlet and outlet of the membrane’s fluidic channels. Hence, a tunable administration of drugs is ensured from the nanochannel drug delivery system. The membrane will be incorporated into a peek implantable capsule, which will include drug reservoir, control hardware and RF system to allow suitable therapeutic regimens in real-time. Therefore, this new nanotechnology offers tremendous potential solutions to manage chronic disease such as cancer, heart disease, circadian dysfunction, pain and stress.Keywords: nanochannel membrane, drug delivery, tunable release, personalized administration, nanoscale transport, biomems
Procedia PDF Downloads 3152585 Study on the Stability of Large Space Expandable Parabolic Cylindrical Antenna
Authors: Chuanzhi Chen, Wenjing Yu
Abstract:
Parabolic cylindrical deployable antenna has the characteristics of wide cutting width, strong directivity, high gain, and easy automatic beam scanning. While, due to its large size, high flexibility, and strong coupling, the deployment process of parabolic cylindrical deployable antenna presents such problems as unsynchronized deployment speed, large local deformation and discontinuous switching of deployment state. A large deployable parabolic cylindrical antenna is taken as the research object, and the problem of unfolding process instability of cylindrical antenna is studied in the paper, which is caused by multiple factors such as multiple closed loops, elastic deformation, motion friction, and gap collision. Firstly, the multi-flexible system dynamics model of large-scale parabolic cylindrical antenna is established to study the influence of friction and elastic deformation on the stability of large multi-closed loop antenna. Secondly, the evaluation method of antenna expansion stability is studied, and the quantitative index of antenna configuration design is proposed to provide a theoretical basis for improving the overall performance of the antenna. Finally, through simulation analysis and experiment, the development dynamics and stability of large-scale parabolic cylindrical antennas are verified by in-depth analysis, and the principles for improving the stability of antenna deployment are summarized.Keywords: multibody dynamics, expandable parabolic cylindrical antenna, stability, flexible deformation
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