Search results for: free space
6547 Zonal and Sequential Extraction Design for Large Flat Space to Achieve Perpetual Tenability
Authors: Mingjun Xu, Man Pun Wan
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This study proposed an effective smoke control strategy for the large flat space with a low ceiling to achieve the requirement of perpetual tenability. For the large flat space with a low ceiling, the depth of the smoke reservoir is very shallow, and it is difficult to perpetually constrain the smoke within a limited space. A series of numerical tests were conducted to determine the smoke strategy. A zonal design i.e., the fire zone and two adjacent zones was proposed and validated to be effective in controlling smoke. Once a fire happens in a compartment space, the Engineered Smoke Control (ESC) system will be activated in three zones i.e., the fire zone, in which the fire happened, and two adjacent zones. The smoke can be perpetually constrained within the three smoke zones. To further improve the extraction efficiency, sequential activation of the ESC system within the 3 zones turned out to be more efficient than simultaneous activation. Additionally, the proposed zonal and sequential extraction design can reduce the mechanical extraction flow rate by up to 40.7 % as compared to the conventional method, which is much more economical than that of the conventional method.Keywords: performance-based design, perpetual tenability, smoke control, fire plume
Procedia PDF Downloads 636546 Stem Covers of Leibniz n-Algebras
Authors: Natália Maria Rego
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ALeibnizn-algebraGis aK-vector space endowed whit a n-linearbracket operation [-,…-] : GG … G→ Gsatisfying the fundamental identity, which can be expressed saying that the right multiplication map Ry2, …, ᵧₙ: Gn→ G, Rᵧ₂, …, ᵧₙn(ˣ¹, …, ₓₙ) = [[ˣ¹, …, ₓₙ], ᵧ₂, …, ᵧₙ], is a derivation. This structure, together with its skew-symmetric version, named as Lie n-algebra or Filippov algebra, arose in the setting of Nambumechanics, an n-ary generalization of the Hamiltonian mechanics. Thefirst goal of this work is to provide a characterization of various classes of central extensions of Leibniz n-algebras in terms of homological properties. Namely, Commutator extension, Quasi-commutator extension, Stem extension, and Stem cover. These kind of central extensions are characterized by means of the character of the map *(E): nHL1(G) → M provided by the five-term exact sequence in homology with trivial coefficients of Leibniz n-algebras associated to an extension E : 0 → M → K → G → 0. For a free presentation 0 →R→ F →G→ 0of a Leibniz n-algebra G,the term M(G) = (R[F,…n.., F])/[R, F,..n-1..,F] is called the Schur multiplier of G, which is a Baer invariant, i.e., it does not depend on the chosen free presentation, and it is isomorphic to the first Leibniz n-algebras homology with trivial coefficients of G. A central extension of Leibniz n-algebras is a short exact sequenceE : 0 →M→K→G→ 0such that [M, K,.. ⁿ⁻¹.., K]=0. It is said to be a stem extension if M⊆[G, .. n.., G]. Additionally, if the induced map M(K) → M(G) is the zero map, then the stem extension Eis said to be a stem cover. The second aim of this work is to analyze the interplay between stem covers of Leibniz n-algebras and the Schur multiplier. Concretely, in the case of finite-dimensional Leibniz n-algebras, we show the existence of coverings, and we prove that all stem covers with finite-dimensional Schur multiplier are isoclinic. Additionally, we characterize stem covers of perfect Leibniz n-algebras.Keywords: leibniz n-algebras, central extensions, Schur multiplier, stem cover
Procedia PDF Downloads 1546545 Agegraphic Dark Energy with GUP
Authors: H. R. Fazlollahi
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Dark Energy origin is unknown and so describing this mysterious component in large scale structure needs to manipulate our theories in general relativity. Although in most models, dark energy arises from extra terms through modifying Einstein-Hilbert action, maybe its origin traces back to fundamental aspects of ground energy of space-time given in quantum mechanics. Hence, diluting space-time in general relativity with quantum mechanics properties leads to the Karolyhazy relation corresponding energy density of quantum fluctuations of space-time. Through generalized uncertainty principle and an eye to Karolyhazy approach in this study we extend energy density of quantum fluctuations of space-time. Also, the application of this idea is considered in late time evolution and we have shown how extra term in generalized uncertainty principle plays as a plausible interaction term role in suggested model.Keywords: generalized uncertainty principle, karolyhazy approach, agegraphic dark energy, cosmology
Procedia PDF Downloads 696544 Survey of Free-Range inhabitants of Federal University of Agriculture Abeokuta Zoological Park
Authors: Matthew Olanrewaju Ibiyomi
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The study examined the abundance of free-range natural inhabitants of the Federal University of Agriculture, Abeokuta (FUNAAB) Zoo Park. A baseline data of free-ranging inhabitants of the Park is essential to monitor trends and institute conservation plans through unsustainable natural resources exploitation and habitat destruction. Four transects were selected across the study area. Each transect was traversed for a period of four months and observations was carried out twice a day. The Four existing tracks explored during the study were the aviary, reptile, carnivore and primate tracks. Data were analyzed using descriptive statistics. The findings from this study revealed that 8 species of natural inhabitants were identified, which were the Vervet monkey (Chlorocebuspygerythrus), Maxwell duiker(Philantombamaxwellii), Mongoose (Herpestidaespp), Bushbuck(Tragelaphusscriptus), Cobra (Najanaja), Ground squirrel (Marmotinispp), Senegal coucal(Centropus senegalensis), Black kite (Milvus migrans). The result further showed that a total of 115 animals were encountered in the primate transect, 77 animals in the carnivores transect, 46 animals in the aviary transect and 34 animals in the ungulates transect by the representative of 43.3%, 28.3%, 15.8% and 12.5% respectively. Human activities and level of disturbance were observed to have affected the abundance and distribution of animals at Funaab Zoo Park. Continuous field inventory is recommended to ascertain the dynamics of animals observed as free-range inhabitants in this study.Keywords: abundance, ecosystem, extinction, free-range
Procedia PDF Downloads 846543 Analyzing Extended Reality Technologies for Human Space Exploration
Authors: Morgan Kuligowski, Marientina Gotsis
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Extended reality (XR) technologies share an intertwined history with spaceflight and innovation. New advancements in XR technologies offer expanding possibilities to advance the future of human space exploration with increased crew autonomy. This paper seeks to identify implementation gaps between existing and proposed XR space applications to inform future mission planning. A review of virtual reality, augmented reality, and mixed reality technologies implemented aboard the International Space Station revealed a total of 16 flown investigations. A secondary set of ground-tested XR human spaceflight applications were systematically retrieved from literature sources. The two sets of XR technologies, those flown and those existing in the literature were analyzed to characterize application domains and device types. Comparisons between these groups revealed untapped application areas for XR to support crew psychological health, in-flight training, and extravehicular operations on future flights. To fill these roles, integrating XR technologies with advancements in biometric sensors and machine learning tools is expected to transform crew capabilities.Keywords: augmented reality, extended reality, international space station, mixed reality, virtual reality
Procedia PDF Downloads 2096542 Detectability Analysis of Typical Aerial Targets from Space-Based Platforms
Authors: Yin Zhang, Kai Qiao, Xiyang Zhi, Jinnan Gong, Jianming Hu
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In order to achieve effective detection of aerial targets over long distances from space-based platforms, the mechanism of interaction between the radiation characteristics of the aerial targets and the complex scene environment including the sunlight conditions, underlying surfaces and the atmosphere are analyzed. A large simulated database of space-based radiance images is constructed considering several typical aerial targets, target working modes (flight velocity and altitude), illumination and observation angles, background types (cloud, ocean, and urban areas) and sensor spectrums ranging from visible to thermal infrared. The target detectability is characterized by the signal-to-clutter ratio (SCR) extracted from the images. The influence laws of the target detectability are discussed under different detection bands and instantaneous fields of view (IFOV). Furthermore, the optimal center wavelengths and widths of the detection bands are suggested, and the minimum IFOV requirements are proposed. The research can provide theoretical support and scientific guidance for the design of space-based detection systems and on-board information processing algorithms.Keywords: space-based detection, aerial targets, detectability analysis, scene environment
Procedia PDF Downloads 1436541 Understanding the Role of Alkali-Free Accelerators in Wet-Mix Shotcrete
Authors: Ezgi Yurdakul, Klaus-Alexander Rieder, Richard Sibbick
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Most of the shotcrete projects require compliance with meeting a specified early-age strength target (e.g., reaching 1 MPa in 1 hour) that is selected based on the underground conditions. To meet the desired early-age performance characteristics, accelerators are commonly used as they increase early-age strength development rate and accelerate the setting thereby reducing sagging and rebound. The selection of accelerator type and its dosage is made by the setting time and strength required for the shotcrete application. While alkaline and alkali-free accelerators are the two main types used in wet-mix shotcrete; alkali-free admixtures increasingly substitute the alkaline accelerators to improve the performance and working safety. This paper aims to evaluate the impact of alkali-free accelerators in wet-mix on various tests including set time, early and later-age compressive strength, boiled absorption, and electrical resistivity. Furthermore, the comparison between accelerated and non-accelerated samples will be made to demonstrate the interaction between cement and accelerators. Scanning electron microscopy (SEM), fluorescent resin impregnated thin section and cut and polished surface images will be used to understand the microstructure characterization of mixes in the presence of accelerators.Keywords: accelerators, chemical admixtures, shotcrete, sprayed concrete
Procedia PDF Downloads 1656540 Comparison of Leeway Space Predictions Using Moyers and Tanaka-Johnston Upper Jaw and Lower Jaw on Batak Tribe Between Male and Female in Elementary School Students in Medan City, Sumatera Utara, Indonesia: A Cross-sectional Study
Authors: Hilda Fitria Lubis, Erna Sulistyawati
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Objective: The study aims to compare Leeway space averages between Moyers and Tanaka-Johnston's analysis of elementary school students from the Batak tribe in Medan City. Material and Methods: The study involved 106 students from the Batak tribe elementary school in Medan, comprising 53 male and 53 female students. The samples obtained were then printed on both jaws to obtain a working model, and the mesiodistal width of the four permanent biting teeth of the lower jaw and the amount of space available on the canine-premolar region, as well as the predicted mesiodistal number of the canine-premolar on the Moyers probability table with a 75% degree of confidence and the Tanaka-Johnston formula. Results: Using Moyers analysis, students at Batak Elementary School in Medan City have an average Leeway space value of 2 mm on the upper jaw and 2.78 mm on the lower jaw. The average Leeway spatial value using Tanaka-Johnston analysis in the Batak tribe in elementary school in Medan City is 1.33 mm on the top jaw and 2.39 mm on the bottom jaw. Conclusion: According to Moyers and Tanaka-Johnsnton's analysis of both the upper and lower jaws in elementary school students of the Batak tribe in Medan City, there is a significant difference between Leeway's average space.Keywords: leeways space, batak tribe, genders, diagnosis
Procedia PDF Downloads 186539 Finding the Free Stream Velocity Using Flow Generated Sound
Authors: Saeed Hosseini, Ali Reza Tahavvor
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Sound processing is one the subjects that newly attracts a lot of researchers. It is efficient and usually less expensive than other methods. In this paper the flow generated sound is used to estimate the flow speed of free flows. Many sound samples are gathered. After analyzing the data, a parameter named wave power is chosen. For all samples, the wave power is calculated and averaged for each flow speed. A curve is fitted to the averaged data and a correlation between the wave power and flow speed is founded. Test data are used to validate the method and errors for all test data were under 10 percent. The speed of the flow can be estimated by calculating the wave power of the flow generated sound and using the proposed correlation.Keywords: the flow generated sound, free stream, sound processing, speed, wave power
Procedia PDF Downloads 4086538 Coding and Decoding versus Space Diversity for Rayleigh Fading Radio Frequency Channels
Authors: Ahmed Mahmoud Ahmed Abouelmagd
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The diversity is the usual remedy of the transmitted signal level variations (Fading phenomena) in radio frequency channels. Diversity techniques utilize two or more copies of a signal and combine those signals to combat fading. The basic concept of diversity is to transmit the signal via several independent diversity branches to get independent signal replicas via time – frequency - space - and polarization diversity domains. Coding and decoding processes can be an alternative remedy for fading phenomena, it cannot increase the channel capacity, but it can improve the error performance. In this paper we propose the use of replication decoding with BCH code class, and Viterbi decoding algorithm with convolution coding; as examples of coding and decoding processes. The results are compared to those obtained from two optimized selection space diversity techniques. The performance of Rayleigh fading channel, as the model considered for radio frequency channels, is evaluated for each case. The evaluation results show that the coding and decoding approaches, especially the BCH coding approach with replication decoding scheme, give better performance compared to that of selection space diversity optimization approaches. Also, an approach for combining the coding and decoding diversity as well as the space diversity is considered, the main disadvantage of this approach is its complexity but it yields good performance results.Keywords: Rayleigh fading, diversity, BCH codes, Replication decoding, convolution coding, viterbi decoding, space diversity
Procedia PDF Downloads 4336537 ‘A Ghost of One’s Own’: Spectral Intrusions and Trauma in the Poetry of Joanna Baillie and Anne Bannerman
Authors: Elli Karampela
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In Specters of Marx (1993), Jacques Derrida refers to the ghost as an Other presence that occupies the space of the self and emanates from there, haunting in its shadowy pastness and threatening/striving to break free. In times of change, ghosts both reflect the dissolution of set principles and voice traumas of the past that create a sense of fear and instability. This paper observes the way female ghosts create connections with the living in the poetry of Joanna Baillie and Anne Bannerman, both integral, albeit under-researched in different ways, writers of the English Romantic period working in the aftermath of the French Revolution. Especially at the beginning of the nineteenth century, when ghost narratives were devoured by readers and enjoyed as stories that re-awakened sensation in times of revolution, there was at the same time fear of intrusion by terror’s unruly forces that threatened to turn the readers restless. The ghost was particularly dangerous because it was associated with memory and the intrusion of past trauma in the here and now. As will be seen, both Baillie and Bannerman explore the idea of the female ghost’s ‘return’ (a Freudian term that will be approached) which breaks both time and space boundaries to raise the suppressed female voice, threaten stability, and correct wrongs. As a result, the varied manifestations of female ghosts render Baillie and Bannerman active in the contemporary discourse about human rights and the reclamation of the agency.Keywords: poetry, romanticism, spectrality, trauma, women
Procedia PDF Downloads 2066536 Influence and Depiction of Power in an Urban Space
Authors: Kalpeshkumar Patel, Nikita Manvi
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The paper is an attempt to understand the influence and depiction of power in an urban space by throwing light across a few examples across the architectural timeline. Power has been the medium through which ideologies function, as witnessed across the timeline. The center to understand this ideology is to apprehend how power is formed, captured, owned, traded, and distorted. Every urban space has power embedded in it, either for the people who are imposing it or for the public who are receiving it. The most fundamental question in the issue of power is who – who will judge, whose tastes will matter and whose interests are being served. Power is expressed and reinforced by regular means, a boundary and gates, a parade route, a dominant landmark, play of shape or scale in elevation, ceremonial axis, boulevards and avenues, the vista, bilateral symmetry, or regular order. Even if people accept the psychological efficacy of these forms, the way they perceive them may vary depending on the subject. They are cold devices of power used to make some people submit to others. Yet it is also true that these symbolic forms are attractive because they speak to the deep emotions of people. They do indeed give us a sense of security, stability and continuity, awe and pride. The Urban Space for mass assembly is an idea that continues to seduce dictators and democracies. It is a tradition as old as an agora and as manipulative as Baroque Rome.Keywords: urban space, aggrandization, city planning, landscape, supremacy, democratic
Procedia PDF Downloads 1246535 Implementation of Free-Field Boundary Condition for 2D Site Response Analysis in OpenSees
Authors: M. Eskandarighadi, C. R. McGann
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It is observed from past experiences of earthquakes that local site conditions can significantly affect the strong ground motion characteristics experience at the site. One-dimensional seismic site response analysis is the most common approach for investigating site response. This approach assumes that soil is homogeneous and infinitely extended in the horizontal direction. Therefore, tying side boundaries together is one way to model this behavior, as the wave passage is assumed to be only vertical. However, 1D analysis cannot capture the 2D nature of wave propagation, soil heterogeneity, and 2D soil profile with features such as inclined layer boundaries. In contrast, 2D seismic site response modeling can consider all of the mentioned factors to better understand local site effects on strong ground motions. 2D wave propagation and considering that the soil profile on the two sides of the model may not be identical clarifies the importance of a boundary condition on each side that can minimize the unwanted reflections from the edges of the model and input appropriate loading conditions. Ideally, the model size should be sufficiently large to minimize the wave reflection, however, due to computational limitations, increasing the model size is impractical in some cases. Another approach is to employ free-field boundary conditions that take into account the free-field motion that would exist far from the model domain and apply this to the sides of the model. This research focuses on implementing free-field boundary conditions in OpenSees for 2D site response analysisComparisons are made between 1D models and 2D models with various boundary conditions, and details and limitations of the developed free-field boundary modeling approach are discussed.Keywords: boundary condition, free-field, opensees, site response analysis, wave propagation
Procedia PDF Downloads 1476534 Quantum Localization of Vibrational Mirror in Cavity Optomechanics
Authors: Madiha Tariq, Hena Rabbani
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Recently, cavity-optomechanics becomes an extensive research field that has manipulated the mechanical effects of light for coupling of the optical field with other physical objects specifically with regards to dynamical localization. We investigate the dynamical localization (both in momentum and position space) for a vibrational mirror in a Fabry-Pérot cavity driven by a single mode optical field and a transverse probe field. The weak probe field phenomenon results in classical chaos in phase space and spatio temporal dynamics in position |ψ(x)²| and momentum space |ψ(p)²| versus time show quantum localization in both momentum and position space. Also, we discuss the parametric dependencies of dynamical localization for a designated set of parameters to be experimentally feasible. Our work opens an avenue to manipulate the other optical phenomena and applicability of proposed work can be prolonged to turn-able laser sources in the future.Keywords: dynamical localization, cavity optomechanics, Hamiltonian chaos, probe field
Procedia PDF Downloads 1456533 Determination of the Gain in Learning the Free-Fall Motion of Bodies by Applying the Resource of Previous Concepts
Authors: Ricardo Merlo
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In this paper, we analyzed the different didactic proposals for teaching about the free fall motion of bodies available online. An important aspect was the interpretation of the direction and sense of the acceleration of gravity and of the falling velocity of a body, which is why we found different applications of the Cartesian reference system used and also different graphical presentations of the velocity as a function of time and of the distance traveled vertically by the body in the period of time that it was dropped from a height h0. In this framework, a survey of previous concepts was applied to a voluntary group of first-year university students of an Engineering degree before and after the development of the class of the subject in question. Then, Hake's index (0.52) was determined, which resulted in an average learning gain from the meaningful use of the reference system and the respective graphs of v=ƒ (t) and h=ƒ (t).Keywords: didactic gain, free–fall, physics teaching, previous knowledge
Procedia PDF Downloads 1576532 The Use of Artificial Intelligence in the Context of a Space Traffic Management System: Legal Aspects
Authors: George Kyriakopoulos, Photini Pazartzis, Anthi Koskina, Crystalie Bourcha
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The need for securing safe access to and return from outer space, as well as ensuring the viability of outer space operations, maintains vivid the debate over the promotion of organization of space traffic through a Space Traffic Management System (STM). The proliferation of outer space activities in recent years as well as the dynamic emergence of the private sector has gradually resulted in a diverse universe of actors operating in outer space. The said developments created an increased adverse impact on outer space sustainability as the case of the growing number of space debris clearly demonstrates. The above landscape sustains considerable threats to outer space environment and its operators that need to be addressed by a combination of scientific-technological measures and regulatory interventions. In this context, recourse to recent technological advancements and, in particular, to Artificial Intelligence (AI) and machine learning systems, could achieve exponential results in promoting space traffic management with respect to collision avoidance as well as launch and re-entry procedures/phases. New technologies can support the prospects of a successful space traffic management system at an international scale by enabling, inter alia, timely, accurate and analytical processing of large data sets and rapid decision-making, more precise space debris identification and tracking and overall minimization of collision risks and reduction of operational costs. What is more, a significant part of space activities (i.e. launch and/or re-entry phase) takes place in airspace rather than in outer space, hence the overall discussion also involves the highly developed, both technically and legally, international (and national) Air Traffic Management System (ATM). Nonetheless, from a regulatory perspective, the use of AI for the purposes of space traffic management puts forward implications that merit particular attention. Key issues in this regard include the delimitation of AI-based activities as space activities, the designation of the applicable legal regime (international space or air law, national law), the assessment of the nature and extent of international legal obligations regarding space traffic coordination, as well as the appropriate liability regime applicable to AI-based technologies when operating for space traffic coordination, taking into particular consideration the dense regulatory developments at EU level. In addition, the prospects of institutionalizing international cooperation and promoting an international governance system, together with the challenges of establishment of a comprehensive international STM regime are revisited in the light of intervention of AI technologies. This paper aims at examining regulatory implications advanced by the use of AI technology in the context of space traffic management operations and its key correlating concepts (SSA, space debris mitigation) drawing in particular on international and regional considerations in the field of STM (e.g. UNCOPUOS, International Academy of Astronautics, European Space Agency, among other actors), the promising advancements of the EU approach to AI regulation and, last but not least, national approaches regarding the use of AI in the context of space traffic management, in toto. Acknowledgment: The present work was co-funded by the European Union and Greek national funds through the Operational Program "Human Resources Development, Education and Lifelong Learning " (NSRF 2014-2020), under the call "Supporting Researchers with an Emphasis on Young Researchers – Cycle B" (MIS: 5048145).Keywords: artificial intelligence, space traffic management, space situational awareness, space debris
Procedia PDF Downloads 2476531 ΕSW01: A Methodology for Approaching the Design of Interior Spaces
Authors: Eirini Krasaki
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This paper addresses the problem of designing spaces in a consistently changing environment. Space is considered as a totality of forces that coexist in the same place. Forces form the identity of space and characterize the entities that coexist within the same totality. Interior space is considered as a totality of forces which develop within an envelope. This research focuses on the formation of the tripole space-forces-totality and studies the relation of this tripole to the interior space. The point of departure for this investigation has been set the historic center of Athens, a city center where the majority of building mass is unused. The objective of the study is to connect the development of interior spaces to the alterations of the conceptions that form the built environment. The research focuses on Evripidou street, an axis around which expand both commercial and residential centers. Along Evripidou street, three case studies elaborate: a) In case study 01, Evripidou street is examined as a megastructure in which totalities of interior spaces develop. b) In case study 02, a particular group of entities (polykatoikia) that expand in Evripidou street is investigated. c) In case study 03, a particular group of entities (apartment) that derives from a specific envelope is investigated. Throughout the studies and comparisons of different scales, a design methodology that addresses the design of interior space in relation to the dynamics of the built environment is evolved.Keywords: methodology, research by design, interior, envelope, dynamics
Procedia PDF Downloads 1706530 Relaxor Ferroelectric Lead-Free Na₀.₅₂K₀.₄₄Li₀.₀₄Nb₀.₈₄Ta₀.₁₀Sb₀.₀₆O₃ Ceramic: Giant Electromechanical Response with Intrinsic Polarization and Resistive Leakage Analyses
Authors: Abid Hussain, Binay Kumar
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Environment-friendly lead-free Na₀.₅₂K₀.₄₄Li₀.₀₄Nb₀.₈₄Ta₀.₁₀Sb₀.₀₆O₃ (NKLNTS) ceramic was synthesized by solid-state reaction method in search of a potential candidate to replace lead-based ceramics such as PbZrO₃-PbTiO₃ (PZT), Pb(Mg₁/₃Nb₂/₃)O₃-PbTiO₃ (PMN-PT) etc., for various applications. The ceramic was calcined at temperature 850 ᵒC and sintered at 1090 ᵒC. The powder X-Ray Diffraction (XRD) pattern revealed the formation of pure perovskite phase having tetragonal symmetry with space group P4mm of the synthesized ceramic. The surface morphology of the ceramic was studied using Field Emission Scanning Electron Microscopy (FESEM) technique. The well-defined grains with homogeneous microstructure were observed. The average grain size was found to be ~ 0.6 µm. A very large value of piezoelectric charge coefficient (d₃₃ ~ 754 pm/V) was obtained for the synthesized ceramic which indicated its potential for use in transducers and actuators. In dielectric measurements, a high value of ferroelectric to paraelectric phase transition temperature (Tm~305 ᵒC), a high value of maximum dielectric permittivity ~ 2110 (at 1 kHz) and a very small value of dielectric loss ( < 0.6) were obtained which suggested the utility of NKLNTS ceramic in high-temperature ferroelectric devices. Also, the degree of diffuseness (γ) was found to be 1.61 which confirmed a relaxor ferroelectric behavior in NKLNTS ceramic. P-E hysteresis loop was traced and the value of spontaneous polarization was found to be ~11μC/cm² at room temperature. The pyroelectric coefficient was obtained to be very high (p ∼ 1870 μCm⁻² ᵒC⁻¹) for the present case indicating its applicability in pyroelectric detector applications including fire and burglar alarms, infrared imaging, etc. NKLNTS ceramic showed fatigue free behavior over 107 switching cycles. Remanent hysteresis task was performed to determine the true-remanent (or intrinsic) polarization of NKLNTS ceramic by eliminating non-switchable components which showed that a major portion (83.10 %) of the remanent polarization (Pr) is switchable in the sample which makes NKLNTS ceramic a suitable material for memory switching devices applications. Time-Dependent Compensated (TDC) hysteresis task was carried out which revealed resistive leakage free nature of the ceramic. The performance of NKLNTS ceramic was found to be superior to many lead based piezoceramics and hence can effectively replace them for use in piezoelectric, pyroelectric and long duration ferroelectric applications.Keywords: dielectric properties, ferroelectric properties , lead free ceramic, piezoelectric property, solid state reaction, true-remanent polarization
Procedia PDF Downloads 1326529 Effect of Gamma Radiation, Age of Paddy, Rice Variety and Packaging Materials on the Surface Free Fatty Acid Content of Brown Rice
Authors: Zenaida M. De Guzman, Davison T. Baldos, Gilberto T. Diano, Jeff Darren G. Valdez, Levelyn Mitos Tolentino, Gina B. Abrera, Ma. Lucia Cobar, Cristina Gragasin
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One of the factors affecting the quality of brown rice is the free fatty acid produced from surface lipids. It is the purpose of the study to determine the effect of gamma radiation, packaging materials and age and variety of paddy on the surface free fatty acid content using two different brown rice variety, namely, RC-160 and SL-7, packed in two different packaging materials, namely, regular polyethylene bag and Super bag irradiated at 0.5 and 1.0 kGy. Brown rice was produced from 2-week old (Lot 1) and two months old paddy (Lot 2) and irradiated at the Co-60 Multipurpose Irradiation Facility, PNRI. The surface Free Fatty Acid (FFA) content was obtained following the AOCS Official Method (1982) with some modifications. The experiment was laid out using Split-Plot Randomized Control Block Design. Analysis of variance (ANOVA) showed that the effects of variety, age of paddy and interactions of both were both significant. The surface FFA of SL-7 variety was found to be significantly higher than the RC-160 variety for all radiation doses. Likewise, Lot 2 was observed to have higher surface FFA than Lot 1 regardless of packaging material and radiation dose. It was observed that the surface FFA of both varieties packed in both packaging materials increased significantly up to the 2nd or 3rd month of storage and remains the same until the 5th month. On the other hand, radiation dose did not significantly affect the surface free fatty acid content for all storage/sampling time while the packaging material significantly interacts with the type of variety and radiation dose. Gamma radiation was proven to have no significant effect on the surface free fatty acid at 0.5 and 1.0 kGy and further analyses are needed to determine the action of gamma radiation to the activity of enzyme (lipase-induced and microbial) responsible for the production of other lipolytic products and the effect of gamma radiation on the integrity of the packaging materials.Keywords: brown rice, free fatty acid, gamma radiation, polyethylene bag
Procedia PDF Downloads 3826528 Effects of Colour Choices On the Moods of People in Residential Interiors
Authors: Nishtha Kumar
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In order to understand how people like their interiors and how they feel inside a space, it is important to know the effect that the Colour of the space has on these individuals. Understanding this effect with the help of variables like colour choices of walls, furnishings, lighting, and the lifestyle of people will give a more clear understanding of the individual’s preferences and choices and how they feel about various colours and spaces. This paper focuses on understanding the various moods of people and the psychological effect that the colour of space has on the person living in it. An extensive literature review was conducted to analyse the effect of these variables of colour on the moods of people living in residential interiors. Alongside, a questionnaire survey was conducted to note the responses of people living in residential buildings who have got their interiors done regarding how different colours in their houses makes them feel and if it affects their mood. The results of this survey have helped in providing a better understanding of the relationship between various colours and how different people associate different moods with the same colour. Thus, such results allow us to have a deeper understanding of the effect of colour in residential interiors on individuals and how the colour of a space can affect the state of mind and mood of an individual. This result helps interior designers to incorporate colours into space according to the moods of the individual and understand how every colour depicts a different emotion in different human beings.Keywords: colour, residental interiors, psychological effect, people, different moods
Procedia PDF Downloads 1066527 Thinking about Drawing: The Evolution of Architectural Education in China After 1949
Authors: Wang Yanze
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Architectural design results from the interaction between space and drawing. Stemming from the Beaux-Arts architectural education, drawing kept its dominant position in teaching and learning process for centuries. However, this education system is being challenged in the present time due to the development of the times. Based on the architectural education of China after 1949, a brief introduction to the history of the evolution of the design concept and drawing is given in this paper. Illustrating with the reference to the students’ works in Nanjing Institute of Technology, the predecessor of Southeast University, in China, the paper analyses the relationship between concept and representation, as well as the participation of Space, the modernism discourse. This process contains the transmission of the character of architects, the renovation of drawing skills and the profound social background. With different purposes, the emphasis on representation tends to be combined with the operation on space, and the role of drawing in architectural design process also changes. Therefore, based on the continuity of the traditional architectural education system, the discussion on the “Drawing of Space” in contemporary education system is proposed.Keywords: architectural education, beaux-arts, drawing, modernism
Procedia PDF Downloads 4836526 Approximation to the Hardy Operator on Topological Measure Spaces
Authors: Kairat T. Mynbaev, Elena N. Lomakina
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We consider a Hardy-type operator generated by a family of open subsets of a Hausdorff topological space. The family is indexed with non-negative real numbers and is totally ordered. For this operator, we obtain two-sided bounds of its norm, a compactness criterion, and bounds for its approximation numbers. Previously, bounds for its approximation numbers have been established only in the one-dimensional case, while we do not impose any restrictions on the dimension of the Hausdorff space. The bounds for the norm and conditions for compactness earlier have been found using different methods by G. Sinnamon and K. Mynbaev. Our approach is different in that we use domain partitions for all problems under consideration.Keywords: approximation numbers, boundedness and compactness, multidimensional Hardy operator, Hausdorff topological space
Procedia PDF Downloads 986525 Design Intervention to Achieve Space Efficiency for Commercial Interiors
Authors: Hari Krishna Ayyappa, Reenu Singh
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Rising population and restricted land for development has led towards the growth of vertical buildings and small complexes. It provides many possibilities to change the shape and size of internal space in addition to the social impacts on the commercial spaces. With the increased volatility of necessities of people, the need for mental and physical comfort has continuously increased. . Living in a small space musts minimalist and space- saving cabinetwork results to sustain mortal good. This paper attempts to explore the Influence of Using Minimalist Furniture on the Efficiency of the commercial Space interiors by means of the variable resulting from preceding studies based on literature. A literature review was conducted on research articles to understand the contributing variables in a well designed small commercial spaces. A questionnaire survey was conducted to understand the layout of small commercial spaces with respect to Environmental impact, material, Design elements, Modern approach, Layered lightings, and colours. The problem of small spaces can be resolved by some ways; it's still needed for cabinetwork to develop to be more innovative to accommodate small living spaces. Since cabinetwork is a necessity and not luxury, everybody is in need of it. The spatial factors affecting overall satisfaction at a detailed position were bandied. The variable helped in proposing design ideation and mock ups to explore improved interiors. This paper concludes that most of the principles of the minimalist approach have been overlooked at, which had an impact on the space efficiency in commercial spaces like storage rooms, office area, retail stores, restaurants, and other spaces where business is conducted.Keywords: materials, modern approach, space efficiency, tall commercial buildings
Procedia PDF Downloads 1036524 Effect of Water Hardness and Free Residual Chlorine on Black Tea Brew
Authors: P. Murugesan, G. Venkateswaran, V. A. Shanmuga Selvan
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Water used for brewing tea plays a major role in the quality of tea. Water with higher hardness gives very dark coloured brew. This study was conducted to determine the effect of water hardness and free residual chlorine on the quality of black tea liquor. Theaflavin (TF) and Thearubigin (TR) levels are lower in comparison with the tea brewed in distilled water. At the same time, there is an increase in High Polymerized Substance (HPS) and Total Liquor Colour (TLC). While water with higher hardness has a negative impact on tea brew, water with high concentration of free residual chlorine did not affect the quality of tea brew.Keywords: Theaflavin, Thearubigin, high polymerised substance, total liquor colour, hardness, residual chlorine
Procedia PDF Downloads 2546523 Modeling and Experimental Verification of Crystal Growth Kinetics in Glass Forming Alloys
Authors: Peter K. Galenko, Stefanie Koch, Markus Rettenmayr, Robert Wonneberger, Evgeny V. Kharanzhevskiy, Maria Zamoryanskaya, Vladimir Ankudinov
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We analyze the structure of undercooled melts, crystal growth kinetics and amorphous/crystalline microstructure of rapidly solidifying glass-forming Pd-based and CuZr-based alloys. A dendrite growth model is developed using a combination of the kinetic phase-field model and mesoscopic sharp interface model. The model predicts features of crystallization kinetics in alloys from thermodynamically controlled growth (governed by the Gibbs free energy change on solidification) to the kinetically limited regime (governed by atomic attachment-detachment processes at the solid/liquid interface). Comparing critical undercoolings observed in the crystallization kinetics with experimental data on melt viscosity, atomistic simulation's data on liquid microstructure and theoretically predicted dendrite growth velocity allows us to conclude that the dendrite growth kinetics strongly depends on the cluster structure changes of the melt. The obtained data of theoretical and experimental investigations are used for interpretation of microstructure of samples processed in electro-magnetic levitator on board International Space Station in the frame of the project "MULTIPHAS" (European Space Agency and German Aerospace Center, 50WM1941) and "KINETIKA" (ROSKOSMOS).Keywords: dendrite, kinetics, model, solidification
Procedia PDF Downloads 1106522 Microgreenspace Regeneration in an Inclusive Perspective
Authors: Li Shiyue
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In an urban built environment, urban green space is scarce, especially around old residential areas. Due to the innate design deficiency and the non-core location of these areas, they lack green space, and the recreational opportunities of the surrounding residents are not guaranteed. Micro greenspace becomes a "patch" to compensate for the urban function. To realize the renewal and transformation of micro greenspace, and make it meet the use needs of most groups, this paper introduces the concept of inclusive design. Based on relevant research at home and abroad, this paper discusses the connotation and current situation of micro greenspace. Combining with the realistic conditions of China, this paper thinks about the planning path of inclusive renewal from the aspects of selecting micro greenspace transformation potential points and exploring the key points of site renewal. Among them, the key points of site renewal are explored from five angles: land guarantee, systematic coordination, refined design, and shared space creation, to provide useful references for related research and practice.Keywords: inclusive design, micro greenspace, old city area, space renewal
Procedia PDF Downloads 566521 Nonlinear Free Surface Flow Simulations Using Smoothed Particle Hydrodynamics
Authors: Abdelraheem M. Aly, Minh Tuan Nguyen, Sang-Wook Lee
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The incompressible smoothed particle hydrodynamics (ISPH) is used to simulate impact free surface flows. In the ISPH, pressure is evaluated by solving pressure Poisson equation using a semi-implicit algorithm based on the projection method. The current ISPH method is applied to simulate dam break flow over an inclined plane with different inclination angles. The effects of inclination angle in the velocity of wave front and pressure distribution is discussed. The impact of circular cylinder over water in tank has also been simulated using ISPH method. The computed pressures on the solid boundaries is studied and compared with the experimental results.Keywords: incompressible smoothed particle hydrodynamics, free surface flow, inclined plane, water entry impact
Procedia PDF Downloads 3976520 A New Approach to Interval Matrices and Applications
Authors: Obaid Algahtani
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An interval may be defined as a convex combination as follows: I=[a,b]={x_α=(1-α)a+αb: α∈[0,1]}. Consequently, we may adopt interval operations by applying the scalar operation point-wise to the corresponding interval points: I ∙J={x_α∙y_α ∶ αϵ[0,1],x_α ϵI ,y_α ϵJ}, With the usual restriction 0∉J if ∙ = ÷. These operations are associative: I+( J+K)=(I+J)+ K, I*( J*K)=( I*J )* K. These two properties, which are missing in the usual interval operations, will enable the extension of the usual linear system concepts to the interval setting in a seamless manner. The arithmetic introduced here avoids such vague terms as ”interval extension”, ”inclusion function”, determinants which we encounter in the engineering literature that deal with interval linear systems. On the other hand, these definitions were motivated by our attempt to arrive at a definition of interval random variables and investigate the corresponding statistical properties. We feel that they are the natural ones to handle interval systems. We will enable the extension of many results from usual state space models to interval state space models. The interval state space model we will consider here is one of the form X_((t+1) )=AX_t+ W_t, Y_t=HX_t+ V_t, t≥0, where A∈ 〖IR〗^(k×k), H ∈ 〖IR〗^(p×k) are interval matrices and 〖W 〗_t ∈ 〖IR〗^k,V_t ∈〖IR〗^p are zero – mean Gaussian white-noise interval processes. This feeling is reassured by the numerical results we obtained in a simulation examples.Keywords: interval analysis, interval matrices, state space model, Kalman Filter
Procedia PDF Downloads 4186519 Recent Advances in Pulse Width Modulation Techniques and Multilevel Inverters
Authors: Satish Kumar Peddapelli
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This paper presents advances in pulse width modulation techniques which refers to a method of carrying information on train of pulses and the information be encoded in the width of pulses. Pulse Width Modulation is used to control the inverter output voltage. This is done by exercising the control within the inverter itself by adjusting the ON and OFF periods of inverter. By fixing the DC input voltage we get AC output voltage. In variable speed AC motors the AC output voltage from a constant DC voltage is obtained by using inverter. Recent developments in power electronics and semiconductor technology have lead improvements in power electronic systems. Hence, different circuit configurations namely multilevel inverters have become popular and considerable interest by researcher are given on them. A fast Space-Vector Pulse Width Modulation (SVPWM) method for five-level inverter is also discussed. In this method, the space vector diagram of the five-level inverter is decomposed into six space vector diagrams of three-level inverters. In turn, each of these six space vector diagrams of three-level inverter is decomposed into six space vector diagrams of two-level inverters. After decomposition, all the remaining necessary procedures for the three-level SVPWM are done like conventional two-level inverter. The proposed method reduces the algorithm complexity and the execution time. It can be applied to the multilevel inverters above the five-level also. The experimental setup for three-level diode-clamped inverter is developed using TMS320LF2407 DSP controller and the experimental results are analysed.Keywords: five-level inverter, space vector pulse wide modulation, diode clamped inverter, electrical engineering
Procedia PDF Downloads 3826518 Application of Model Free Adaptive Control in Main Steam Temperature System of Thermal Power Plant
Authors: Khaing Yadana Swe, Lillie Dewan
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At present, the cascade PID control is widely used to control the super-heating temperature (main steam temperature). As the main steam temperature has the characteristics of large inertia, large time-delay, and time varying, etc., conventional PID control strategy can not achieve good control performance. In order to overcome the bad performance and deficiencies of main steam temperature control system, Model Free Adaptive Control (MFAC) P cascade control system is proposed in this paper. By substituting MFAC in PID of the main control loop of the main steam temperature control, it can overcome time delays, non-linearity, disturbance and time variation.Keywords: model-free adaptive control, cascade control, adaptive control, PID
Procedia PDF Downloads 598