Search results for: geometric frustration
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 710

Search results for: geometric frustration

380 Computational Fluids Dynamics Investigation of the Effect of Geometric Parameters on the Ejector Performance

Authors: Michel Wakim, Rodrigo Rivera Tinoco

Abstract:

Supersonic ejector is an economical device that use high pressure vapor to compress a low pressure vapor without any rotating parts or external power sources. Entrainment ratio is a major characteristic of the ejector performance, so the ejector performance is highly dependent on its geometry. The aim of this paper is to design ejector geometry, based on pre-specified operating conditions, and to study the flow behavior inside the ejector by using computational fluid dynamics ‘CFD’ by using ‘ANSYS FLUENT 15.0’ software. In the first section; 1-D mathematical model is carried out to predict the ejector geometry. The second part describes the flow behavior inside the designed model. CFD is the most reliable tool to reveal the mixing process at different parts of the supersonic turbulent flow and to study the effect of the geometry on the effective ejector area. Finally, the results show the effect of the geometry on the entrainment ratio.

Keywords: computational fluids dynamics, ejector, entrainment ratio, geometry optimization, performance

Procedia PDF Downloads 248
379 Concepts of Modern Design: A Study of Art and Architecture Synergies in Early 20ᵗʰ Century Europe

Authors: Stanley Russell

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Until the end of the 19th century, European painting dealt almost exclusively with the realistic representation of objects and landscapes, as can be seen in the work of realist artists like Gustav Courbet. Architects of the day typically made reference to and recreated historical precedents in their designs. The curriculum of the first architecture school in Europe, The Ecole des Beaux Artes, based on the study of classical buildings, had a profound effect on the profession. Painting exhibited an increasing level of abstraction from the late 19th century, with impressionism, and the trend continued into the early 20th century when Cubism had an explosive effect sending shock waves through the art world that also extended into the realm of architectural design. Architect /painter Le Corbusier with “Purism” was one of the first to integrate abstract painting and building design theory in works that were equally shocking to the architecture world. The interrelationship of the arts, including architecture, was institutionalized in the Bauhaus curriculum that sought to find commonality between diverse art disciplines. Renowned painter and Bauhaus instructor Vassily Kandinsky was one of the first artists to make a semi-scientific analysis of the elements in “non-objective” painting while also drawing parallels between painting and architecture in his book Point and Line to plane. Russian constructivists made abstract compositions with simple geometric forms, and like the De Stijl group of the Netherlands, they also experimented with full-scale constructions and spatial explorations. Based on the study of historical accounts and original artworks, of Impressionism, Cubism, the Bauhaus, De Stijl, and Russian Constructivism, this paper begins with a thorough explanation of the art theory and several key works from these important art movements of the late 19th and early 20th century. Similarly, based on written histories and first-hand experience of built and drawn works, the author continues with an analysis of the theories and architectural works generated by the same groups, all of which actively pursued continuity between their art and architectural concepts. With images of specific works, the author shows how the trend toward abstraction and geometric purity in painting coincided with a similar trend in architecture that favored simple unornamented geometries. Using examples like the Villa Savoye, The Schroeder House, the Dessau Bauhaus, and unbuilt designs by Russian architect Chernikov, the author gives detailed examples of how the intersection of trends in Art and Architecture led to a unique and fruitful period of creative synergy when the same concepts that were used by artists to generate paintings were also used by architects in the making of objects, space, and buildings. In Conclusion, this article examines the extremely pivotal period in art and architecture history from the late 19th to early 20th century when the confluence of art and architectural theory led to many painted, drawn, and built works that continue to inspire architects and artists to this day.

Keywords: modern art, architecture, design methodologies, modern architecture

Procedia PDF Downloads 101
378 Specific Language Impairment: Assessing Bilingual Children for Identifying Children with Specific Language Impairment (SLI)

Authors: Manish Madappa, Madhavi Gayathri Raman

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The primary vehicle of human communication is language. A breakdown occurring in any aspect of communication may lead to frustration and isolation among the learners and the teachers. Over seven percent of the population in the world currently experience limitations and those children who exhibit a deviant/deficient language acquisition curve even when being in a language rich environment as their peers may be at risk of having a language disorder or language impairment. The difficulty may be in the word level [vocabulary/word knowledge] and/or the sentence level [syntax/morphology) Children with SLI appear to be developing normally in all aspects except for their receptive and/or expressive language skills. Thus, it is utmost importance to identify children with or at risk of SLI so that an early intervention can foster language and social growth, provide the best possible learning environment with special support for language to be explicitly taught and a step in providing continuous and ongoing support. The present study looks at Kannada English bilingual children and works towards identifying children at risk of “specific language impairment”. The study was conducted through an exploratory study which systematically enquired into the narratives of young Kannada-English bilinguals and to investigate the data for story structure in their narrative formulations. Oral narrative offers a rich source of data about a child’s language use in a relatively natural context. The fundamental objective is to ensure comparability and to be more universal and thus allows for the evaluation narrative text competence. The data was collected from 10 class three students at a primary school in Mysore, Karnataka and analyzed for macrostructure component reflecting the goal directed behavior of a protagonist who is motivated to carry out some kind of action with the intention of attaining a goal. The results show that the children exhibiting a deviation of -1.25 SD are at risk of SLI. Two learners were identified to be at risk of Specific Language Impairment with a standard deviation of more the 1.25 below the mean score.

Keywords: bilingual, oral narratives, SLI, macrostructure

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377 East West Discourse: An Esoteric Comparison of the Western Philosophy and the Eastern Vedanta

Authors: Chandrabati Chakraborty

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The progressive emergence, in the course of the evolution of life, mind and personality, requires us to assume a creative Principle operating timeless Reality in the temporal. The difference between Western philosophy and that of India, concerns the origin and the purpose of the philosophical enquiry. While the former wonders at the external world, the latter is awareness of perennial suffering associated with human existence. The present world suffers from a basic form of rootlessness,reflecting many psychological, philosophical studies. Alienation,a major theme of human condition in the contemporary epoch has emerged as natural consequences of existential predicament. As Edmund Fuller also observes that individuals suffer not only from famine, ruin or even war but also from devastating inner problems, which are that of estrangement, hopelessness and utter despair. This existentialism is thus considered by Jean Wahl as the “Philosophies of existence”.The post world war scenario well analyses the chaos,annihilation,frustration and anguished estrangement. In such conditions when the West cries out , “What is there?I know first of all that I am.But who am I?.....I am sepeated.What I am seperated from I cannot name it. But I am seperated.”(Dostoevsky:The Confession), Vedantic philosophy looks upon the Pilgrim’s Progress of Humanity as being essentially one,operationg squarely within the bounds of reality, reflecting a basic human experience, outbraving indecorous dictims that have failed to give due honour to human beings,echoing for centuries the Sanskrit slokas with ultimate certitude: II Esa Atma samaha plusina samo masakena samo nagena sama ebhis tribhir lokaih.....sama nena sarvena II (The Atman (Divine Soul) is the same in the ant, the same in the gnat, the same in the elephant, the same in these three worlds....the same in the whole Universe). The present paper aims at a comparative study of cultural and philosophical expression taking into view extensive illustrations from Western Philosophers and The Vedantic,Upanishadic lores of Indian philosophy.

Keywords: existentialism, Vedanta, philosophy, absurdism

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376 Characterizing the Geometry of Envy Human Behaviour Using Game Theory Model with Two Types of Homogeneous Players

Authors: A. S. Mousa, R. I. Rajab, A. A. Pinto

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An envy behavioral game theoretical model with two types of homogeneous players is considered in this paper. The strategy space of each type of players is a discrete set with only two alternatives. The preferences of each type of players is given by a discrete utility function. All envy strategies that form Nash equilibria and the corresponding envy Nash domains for each type of players have been characterized. We use geometry to construct two dimensional envy tilings where the horizontal axis reflects the preference for players of type one, while the vertical axis reflects the preference for the players of type two. The influence of the envy behavior parameters on the Cartesian position of the equilibria has been studied, and in each envy tiling we determine the envy Nash equilibria. We observe that there are 1024 combinatorial classes of envy tilings generated from envy chromosomes: 256 of them are being structurally stable while 768 are with bifurcation. Finally, some conditions for the disparate envy Nash equilibria are stated.

Keywords: game theory, Nash equilibrium, envy Nash behavior, geometric tilings, bifurcation thresholds

Procedia PDF Downloads 189
375 Influence of Bra Band Tension and Underwire Angles on Breast Motion

Authors: Cheuk Wing Lee, Kit Lun Yick, Sun Pui Ng, Joanne Yip

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Daily activities and exercise may result in large displacements of the breasts, which lead to breast pain and discomfort. Therefore, a proper bra design and fit can help to control excessive breast motion to prevent the over-stretching of the connective tissues. Nevertheless, bra fit problems, such as excessively high tension of the shoulder straps and a tight underband could have substantially negative effects on the wear comfort and health of the wearer. The purpose of this study is to, therefore, examine the effects of bra band tension on breast displacement. Usually, human wear trials are carried out, but there are inconsistencies during testing. Therefore, a soft manikin torso is used to examine breast displacement at walking speeds of 2.30 km/h and 4.08 km/h. The breast displacement itself is determined by using a VICON motion capture system. The 3D geometric changes of the underwire bra band tension and the corresponding control of breast movement are also analyzed by using a 3D handheld scanner along with Rapidform software. The results indicate that an appropriate bra band tension can help to reduce breast displacement and provide a comfortable angle for the underwire. The findings can be used by designers and bra engineers as a reference source to advance bra design and development.

Keywords: bra band, bra features, breast displacement, underwire angle

Procedia PDF Downloads 228
374 3D Shape Knitting: Loop Alignment on a Surface with Positive Gaussian Curvature

Authors: C. T. Cheung, R. K. P. Ng, T. Y. Lo, Zhou Jinyun

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This paper aims at manipulating loop alignment in knitting a three-dimensional (3D) shape by its geometry. Two loop alignment methods are introduced to handle a surface with positive Gaussian curvature. As weft knitting is a two-dimensional (2D) knitting mechanism that the knitting cam carrying the feeders moves in two directions only, left and right, the knitted fabric generated grows in width and length but not in depth. Therefore, a 3D shape is required to be flattened to a 2D plane with surface area preserved for knitting. On this flattened plane, dimensional measurements are taken for loop alignment. The way these measurements being taken derived two different loop alignment methods. In this paper, only plain knitted structure was considered. Each knitted loop was taken as a basic unit for loop alignment in order to achieve the required geometric dimensions, without the inclusion of other stitches which give textural dimensions to the fabric. Two loop alignment methods were experimented and compared. Only one of these two can successfully preserve the dimensions of the shape.

Keywords: 3D knitting, 3D shape, loop alignment, positive Gaussian curvature

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373 Coastal Hydraulic Modelling to Ascertain Stability of Rubble Mound Breakwater

Authors: Safari Mat Desa, Othman A. Karim, Mohd Kamarulhuda Samion, Saiful Bahri Hamzah

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Rubble mound breakwater was one of the most popular designs in Malaysia, constructed at the river mouth to dissipate the incoming wave energy from the seaward. Geometrically characteristics in trapezoid, crest width, and bottom width will determine the hypotonus stability, whilst structural height was designed for wave overtopping consideration. Physical hydraulic modelling in two-dimensional facilities was instigated in the flume to test the stability as well as the overtopping rate complied with the method of similarity, namely kinematic, dynamic, and geometric. Scaling effects of wave characteristics were carried out in order to acquire significant interaction of wave height, wave period, and water depth. Results showed two-dimensional physical modelling has proven reliable capability to ascertain breakwater stability significantly.

Keywords: breakwater, geometrical characteristic, wave overtopping, physical hydraulic modelling, method of similarity, wave characteristic

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372 In Situ Laser-Induced Synthesis of Copper Microstructures with High Catalytic Properties and Sensory Characteristics

Authors: Maxim Panov, Evgenia Khairullina, Sergey Ermakov, Oleg Gundobin, Vladimir Kochemirovsky

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The continuous in situ laser-induced catalysis proceeding via generation and growth of nano-sized copper particles was discussed. Also, the simple and lost-cost method for manufacturing of microstructural copper electrodes was proposed. The electrochemical properties of these electrodes were studied by cyclic voltammetry and impedance spectroscopy. The surface of the deposited copper structures (electrodes) was investigated by X-ray photoelectron spectroscopy and atomic force microscopy. These microstructures are highly conductive and porous with a dispersion of pore size ranging from 50 nm to 50 μm. An analytical response of the fabricated copper electrode is 30 times higher than those observed for a pure bulk copper with similar geometric parameters. A study of sensory characteristics for hydrogen peroxide determination showed that the value of Faraday current at the fabricated copper electrode is 2-2.5 orders of magnitude higher than for etalon one.

Keywords: laser-induced deposition, electrochemical electrodes, non-enzymatic sensors, copper

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371 Modeling Electrical Properties of Hetero-Junction-Graphene/Pentacene and Gold/Pentacene

Authors: V. K. Lamba, Abhinandan Bharti

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We investigate the electronic transport properties across the graphene/ pentacene and gold/pentacene interface. Further, we studied the effect of ripples/bends in pentacene using NEGF-DFT approach. Current transport across the pentacene/graphene interface is found to be remarkably different from transport across pentacene/Gold interfaces. We found that current across these interfaces could be accurately modeled by a combination of thermionic and Poole–Frenkel emission. Further, the degree of bend or degrees of the curve formed during ripple formation strongly change the optimized geometric structures, charge distributions, energy bands, and DOS. The misorientation and hybridization of carbon orbitals are associated with a variation in bond lengths and carrier densities, and are the causes of the dramatic changes in the electronic structure during ripple formation. The electrical conductivity decreases with increase in curvature during ripple formation or due to bending of pentacene molecule and a decrease in conductivity is directly proportional to the increase in curvature angle and given by quadratic relation.

Keywords: hetero-junction, grapheme, NEGF-DFT, pentacene, gold/pentacene

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370 Translation and Adaptation of the Assessment Instrument “Kiddycat” for European Portuguese

Authors: Elsa Marta Soares, Ana Rita Valente, Cristiana Rodrigues, Filipa Gonçalves

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Background: The assessment of feelings and attitudes of preschool children in relation to stuttering is crucial. Negative experiences can lead to anxiety, worry or frustration. To avoid the worsening of attitudes and feelings related to stuttering, it is important the early detection in order to intervene as soon as possible through an individualized intervention plan. Then it is important to have Portuguese instruments that allow this assessment. Aims: The aim of the present study is to realize the translation and adaptation of the Communication Attitude Test for Children in Preschool Age and Kindergarten (KiddyCat) for EP. Methodology: For the translation and adaptation process, a methodological study was carried out with the following steps: translation, back translation, assessment by a committee of experts and pre-test. This abstract describes the results of the first two phases of this process. The translation was accomplished by two bilingual individuals without experience in health and any knowledge about the instrument. One of them was an English teacher and the other one a Translator. The back-translation was conducted by two Senior Class Teachers that live in United Kingdom without any knowledge in health and about the instrument. Results and Discussion: In translation there were differences in semantic equivalences of various expressions and concepts. A discussion between the two translators, mediated by the researchers, allowed to achieve the consensus version of the translated instrument. Taking into account the original version of KiddyCAT the results demonstrated that back-translation versions were similar to the original version of this assessment instrument. Although the back-translators used different words, they were synonymous, maintaining semantic and idiomatic equivalences of the instrument’s items. Conclusion: This project contributes with an important resource that can be used in the assessment of feelings and attitudes of preschool children who stutter. This was the first phase of the research; expert panel and pretest are being developed. Therefore, it is expected that this instrument contributes to an holistic therapeutic intervention, taking into account the individual characteristics of each child.

Keywords: assessment, feelings and attitudes, preschool children, stuttering

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369 Spectral Anomaly Detection and Clustering in Radiological Search

Authors: Thomas L. McCullough, John D. Hague, Marylesa M. Howard, Matthew K. Kiser, Michael A. Mazur, Lance K. McLean, Johanna L. Turk

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Radiological search and mapping depends on the successful recognition of anomalies in large data sets which contain varied and dynamic backgrounds. We present a new algorithmic approach for real-time anomaly detection which is resistant to common detector imperfections, avoids the limitations of a source template library and provides immediate, and easily interpretable, user feedback. This algorithm is based on a continuous wavelet transform for variance reduction and evaluates the deviation between a foreground measurement and a local background expectation using methods from linear algebra. We also present a technique for recognizing and visualizing spectrally similar clusters of data. This technique uses Laplacian Eigenmap Manifold Learning to perform dimensional reduction which preserves the geometric "closeness" of the data while maintaining sensitivity to outlying data. We illustrate the utility of both techniques on real-world data sets.

Keywords: radiological search, radiological mapping, radioactivity, radiation protection

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368 3D Point Cloud Model Color Adjustment by Combining Terrestrial Laser Scanner and Close Range Photogrammetry Datasets

Authors: M. Pepe, S. Ackermann, L. Fregonese, C. Achille

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3D models obtained with advanced survey techniques such as close-range photogrammetry and laser scanner are nowadays particularly appreciated in Cultural Heritage and Archaeology fields. In order to produce high quality models representing archaeological evidences and anthropological artifacts, the appearance of the model (i.e. color) beyond the geometric accuracy, is not a negligible aspect. The integration of the close-range photogrammetry survey techniques with the laser scanner is still a topic of study and research. By combining point cloud data sets of the same object generated with both technologies, or with the same technology but registered in different moment and/or natural light condition, could construct a final point cloud with accentuated color dissimilarities. In this paper, a methodology to uniform the different data sets, to improve the chromatic quality and to highlight further details by balancing the point color will be presented.

Keywords: color models, cultural heritage, laser scanner, photogrammetry

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367 Application of Transform Fourier for Dynamic Control of Structures with Global Positioning System

Authors: J. M. de Luis Ruiz, P. M. Sierra García, R. P. García, R. P. Álvarez, F. P. García, E. C. López

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Given the evolution of viaducts, structural health monitoring requires more complex techniques to define their state. two alternatives can be distinguished: experimental and operational modal analysis. Although accelerometers or Global Positioning System (GPS) have been applied for the monitoring of structures under exploitation, the dynamic monitoring during the stage of construction is not common. This research analyzes whether GPS data can be applied to certain dynamic geometric controls of evolving structures. The fundamentals of this work were applied to the New Bridge of Cádiz (Spain), a worldwide milestone in bridge building. GPS data were recorded with an interval of 1 second during the erection of segments and turned to the frequency domain with Fourier transform. The vibration period and amplitude were contrasted with those provided by the finite element model, with differences of less than 10%, which is admissible. This process provides a vibration record of the structure with GPS, avoiding specific equipment.

Keywords: Fourier transform, global position system, operational modal analysis, structural health monitoring

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366 Autonomy in Healthcare Organisations: A Comparative Case Study of Middle Managers in England and Iran

Authors: Maryam Zahmatkesh

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Middle managers form a significant occupational category in organisations. They undertake a vital role, as they sit between the operational and strategic roles. Traditionally they were acting as diplomat administrators, and were only in power to meet the demands of professionals. Following the introduction of internal market, in line with the principles of New Public Management, middle managers have been considered as change agents. More recently, in the debates of middle managers, there is emphasis on entrepreneurialism and enacting strategic role. It was assumed that granting autonomy to the local organisations and the inception of semi-autonomous hospitals (Foundation Trusts in England and Board of Trustees in Iran) would give managers more autonomy to act proactively and innovatively. This thesis explores the hospital middle managers’ perception of and responses to public management reforms (in particular, hospital autonomy) in England and Iran. In order to meet the aims of the thesis, research was undertaken within the interpretative paradigm, in line with social constructivism. Data were collected from interviews with forty-five middle managers, observational fieldwork and documentary analysis across four teaching university hospitals in England and Iran. The findings show the different ways middle managers’ autonomy is constrained in the two countries. In England, middle managers have financial and human recourses, but their autonomy is constrained by government policy and targets. In Iran, middle managers are less constrained by government policy and targets, but they do not have financial and human resources to exercise autonomy. Unbalanced autonomy causes tension and frustration for middle managers. According to neo-institutional theory, organisations are deeply embedded within social, political, economic and normative settings that exert isomorphic and internal population-level pressures to conform to existing and established modes of operation. Health systems which are seeking to devolve autonomy to middle managers must appreciate the multidimensional nature of the autonomy, as well as the wider environment that organisations are embedded, if they are about to improve the performance of managers and their organisations.

Keywords: autonomy, healthcare organisations, middle managers, new public management

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365 The Effect of Midwifery Counseling Based on Gamble Approach on the Coping Strategies of Women with Abortion: A Randomized Controlled Clinical Trial

Authors: Hasanzadeh Tahraband F., Kheirkhah M.

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The trauma resulting from abortion causes fear, frustration, inability, lack of self-confidence, and psychological distress in women. The present study was conducted to determine the effect of midwifery counseling based on the Gamble approach on coping strategies of women with abortion. This randomized controlled clinical trial was conducted on women with abortions in April–October 2021, Karaj, Iran. Ninety-six eligible women were randomly assigned to two 48-member groups with 4, 6, and 8 blocks. The women in the intervention group participated in two 45-75-minute Gamble counseling programs. They were asked to fill out the demographic and fertility information questionnaire before the intervention and the cope operations preference inquiry questionnaire before, immediately (in the 4-6th week of the study), and three months after the intervention. The analysis of the data was done through Chi-square, independent sample t-test. The significance level was considered P<0.05. The results showed that the differences between the two groups before the intervention were not statistically significant in terms of demographic and fertility variables (P>0.05). However, the total mean score of the problem-focused dimension in 3-month post-abortion (97/34±8/69) and the emotion-focused dimension in 4-6 weeks and 3-month post-abortion (34/14±3/48 and 32/41±3/41) in the intervention group was significantly different from the control group (P<0.001). According to the results of the repeated measures ANOVA, the level of coping and its dimensions significantly changed in the intervention group over time (P<0.001). The results of the present study showed that Gamble counseling promoted the problem-focused dimension score and reduced the emotion-focused dimension score in women with abortion. It is recommended that Gamble counseling should be used as midwife-led counseling to increase coping strategies and reduce the psychological distress of women who have experienced abortion.

Keywords: midwife-led counseling, coping strategies, post-abortion, psychological distress, Iran

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364 Generative Design of Acoustical Diffuser and Absorber Elements Using Large-Scale Additive Manufacturing

Authors: Saqib Aziz, Brad Alexander, Christoph Gengnagel, Stefan Weinzierl

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This paper explores a generative design, simulation, and optimization workflow for the integration of acoustical diffuser and/or absorber geometry with embedded coupled Helmholtz-resonators for full-scale 3D printed building components. Large-scale additive manufacturing in conjunction with algorithmic CAD design tools enables a vast amount of control when creating geometry. This is advantageous regarding the increasing demands of comfort standards for indoor spaces and the use of more resourceful and sustainable construction methods and materials. The presented methodology highlights these new technological advancements and offers a multimodal and integrative design solution with the potential for an immediate application in the AEC-Industry. In principle, the methodology can be applied to a wide range of structural elements that can be manufactured by additive manufacturing processes. The current paper focuses on a case study of an application for a biaxial load-bearing beam grillage made of reinforced concrete, which allows for a variety of applications through the combination of additive prefabricated semi-finished parts and in-situ concrete supplementation. The semi-prefabricated parts or formwork bodies form the basic framework of the supporting structure and at the same time have acoustic absorption and diffusion properties that are precisely acoustically programmed for the space underneath the structure. To this end, a hybrid validation strategy is being explored using a digital and cross-platform simulation environment, verified with physical prototyping. The iterative workflow starts with the generation of a parametric design model for the acoustical geometry using the algorithmic visual scripting editor Grasshopper3D inside the building information modeling (BIM) software Revit. Various geometric attributes (i.e., bottleneck and cavity dimensions) of the resonator are parameterized and fed to a numerical optimization algorithm which can modify the geometry with the goal of increasing absorption at resonance and increasing the bandwidth of the effective absorption range. Using Rhino.Inside and LiveLink for Revit, the generative model was imported directly into the Multiphysics simulation environment COMSOL. The geometry was further modified and prepared for simulation in a semi-automated process. The incident and scattered pressure fields were simulated from which the surface normal absorption coefficients were calculated. This reciprocal process was repeated to further optimize the geometric parameters. Subsequently the numerical models were compared to a set of 3D concrete printed physical twin models, which were tested in a .25 m x .25 m impedance tube. The empirical results served to improve the starting parameter settings of the initial numerical model. The geometry resulting from the numerical optimization was finally returned to grasshopper for further implementation in an interdisciplinary study.

Keywords: acoustical design, additive manufacturing, computational design, multimodal optimization

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363 A Simplified, Fabrication-Friendly Acoustophoretic Model for Size Sensitive Particle Sorting

Authors: V. Karamzadeh, J. Adhvaryu, A. Chandrasekaran, M. Packirisamy

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In Bulk Acoustic Wave (BAW) microfluidics, the throughput of particle sorting is dependent on the complex interplay between the geometric configuration of the channel, the size of the particles, and the properties of the fluid medium, which therefore calls for a detailed modeling and understanding of the fluid-particle interaction dynamics under an acoustic field, prior to designing the system. In this work, we propose a simplified Bulk acoustophoretic system that can be used for size dependent particle sorting. A Finite Element Method (FEM) based analytical model has been developed to study the dependence of particle sizes on channel parameters, and the sorting efficiency in a given fluid medium. Based on the results, the microfluidic system has been designed to take into account all the variables involved with the underlying physics, and has been fabricated using an additive manufacturing technique employing a commercial 3D printer, to generate a simple, cost-effective system that can be used for size sensitive particle sorting.

Keywords: 3D printing, 3D microfluidic chip, acoustophoresis, cell separation, MEMS (Microelectromechanical Systems), microfluidics

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362 An Interpretable Data-Driven Approach for the Stratification of the Cardiorespiratory Fitness

Authors: D.Mendes, J. Henriques, P. Carvalho, T. Rocha, S. Paredes, R. Cabiddu, R. Trimer, R. Mendes, A. Borghi-Silva, L. Kaminsky, E. Ashley, R. Arena, J. Myers

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The continued exploration of clinically relevant predictive models continues to be an important pursuit. Cardiorespiratory fitness (CRF) portends clinical vital information and as such its accurate prediction is of high importance. Therefore, the aim of the current study was to develop a data-driven model, based on computational intelligence techniques and, in particular, clustering approaches, to predict CRF. Two prediction models were implemented and compared: 1) the traditional Wasserman/Hansen Equations; and 2) an interpretable clustering approach. Data used for this analysis were from the 'FRIEND - Fitness Registry and the Importance of Exercise: The National Data Base'; in the present study a subset of 10690 apparently healthy individuals were utilized. The accuracy of the models was performed through the computation of sensitivity, specificity, and geometric mean values. The results show the superiority of the clustering approach in the accurate estimation of CRF (i.e., maximal oxygen consumption).

Keywords: cardiorespiratory fitness, data-driven models, knowledge extraction, machine learning

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361 Qualitative Needs Assessment for Development of a Smart Thumb Prosthetic

Authors: Syena Moltaji, Stephanie Posa, Sander Hitzig, Amanda Mayo, Heather Baltzer

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Purpose: To critically assess deficits following thumb amputation and delineate elements of an ideal thumb prosthesis from the end-user perspective. Methods: This was a qualitative study based on grounded theory. End-user stakeholder groups of thumb amputees and prosthetists were interviewed. Transcripts were reviewed whole first for familiarity. Data coding was then performed by two individual authors. Coded units were grouped by similarity and reviewed to reach a consensus. Codes were then analyzed for emergent themes by each author. A consensus meeting was held with all authors to finalize themes. Results: Three patients with traumatic thumb amputation and eight prosthetists were interviewed. Seven themes emerged. First was the significant impact of losing a thumb, in which codes of functional impact, mental impact, and occupational impact were included. The second theme was the unique nature of each thumb amputee, including goals, readiness for prosthesis, nature of the injury, and insurance. The third emergent theme was cost, surrounding government funding, insurability, and prosthetic pricing. The fourth theme was patient frustration, which included mismatches of prosthetic expectations and realities, activity limitations, and causes of devices abandonment. Themes five and six surrounded the strengths and weaknesses of current prosthetics, respectively. Theme seven was the ideal design for a thumb prosthetic, including abilities, suspension, and materials. Conclusions: Representative data from stakeholders mapped the current status of thumb prosthetics. Preferences for an ideal thumb prosthetic emerged, with suggestions for a simple, durable design. The ability to oppose, grasp and sense pressure was reported as functional priorities. Feasible cost and easy fitting emerged as systemic objectives. This data will be utilized in the development of a sensate thumb prosthetic.

Keywords: smart thumb, thumb prosthetic, sensate prosthetic, amputation

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360 A Study of Numerical Reaction-Diffusion Systems on Closed Surfaces

Authors: Mei-Hsiu Chi, Jyh-Yang Wu, Sheng-Gwo Chen

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The diffusion-reaction equations are important Partial Differential Equations in mathematical biology, material science, physics, and so on. However, finding efficient numerical methods for diffusion-reaction systems on curved surfaces is still an important and difficult problem. The purpose of this paper is to present a convergent geometric method for solving the reaction-diffusion equations on closed surfaces by an O(r)-LTL configuration method. The O(r)-LTL configuration method combining the local tangential lifting technique and configuration equations is an effective method to estimate differential quantities on curved surfaces. Since estimating the Laplace-Beltrami operator is an important task for solving the reaction-diffusion equations on surfaces, we use the local tangential lifting method and a generalized finite difference method to approximate the Laplace-Beltrami operators and we solve this reaction-diffusion system on closed surfaces. Our method is not only conceptually simple, but also easy to implement.

Keywords: closed surfaces, high-order approachs, numerical solutions, reaction-diffusion systems

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359 Fast and Efficient Algorithms for Evaluating Uniform and Nonuniform Lagrange and Newton Curves

Authors: Taweechai Nuntawisuttiwong, Natasha Dejdumrong

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Newton-Lagrange Interpolations are widely used in numerical analysis. However, it requires a quadratic computational time for their constructions. In computer aided geometric design (CAGD), there are some polynomial curves: Wang-Ball, DP and Dejdumrong curves, which have linear time complexity algorithms. Thus, the computational time for Newton-Lagrange Interpolations can be reduced by applying the algorithms of Wang-Ball, DP and Dejdumrong curves. In order to use Wang-Ball, DP and Dejdumrong algorithms, first, it is necessary to convert Newton-Lagrange polynomials into Wang-Ball, DP or Dejdumrong polynomials. In this work, the algorithms for converting from both uniform and non-uniform Newton-Lagrange polynomials into Wang-Ball, DP and Dejdumrong polynomials are investigated. Thus, the computational time for representing Newton-Lagrange polynomials can be reduced into linear complexity. In addition, the other utilizations of using CAGD curves to modify the Newton-Lagrange curves can be taken.

Keywords: Lagrange interpolation, linear complexity, monomial matrix, Newton interpolation

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358 Data Challenges Facing Implementation of Road Safety Management Systems in Egypt

Authors: A. Anis, W. Bekheet, A. El Hakim

Abstract:

Implementing a Road Safety Management System (SMS) in a crowded developing country such as Egypt is a necessity. Beginning a sustainable SMS requires a comprehensive reliable data system for all information pertinent to road crashes. In this paper, a survey for the available data in Egypt and validating it for using in an SMS in Egypt. The research provides some missing data, and refer to the unavailable data in Egypt, looking forward to the contribution of the scientific society, the authorities, and the public in solving the problem of missing or unreliable crash data. The required data for implementing an SMS in Egypt are divided into three categories; the first is available data such as fatality and injury rates and it is proven in this research that it may be inconsistent and unreliable, the second category of data is not available, but it may be estimated, an example of estimating vehicle cost is available in this research, the third is not available and can be measured case by case such as the functional and geometric properties of a facility. Some inquiries are provided in this research for the scientific society, such as how to improve the links among stakeholders of road safety in order to obtain a consistent, non-biased, and reliable data system.

Keywords: road safety management system, road crash, road fatality, road injury

Procedia PDF Downloads 89
357 Anonymous Editing Prevention Technique Using Gradient Method for High-Quality Video

Authors: Jiwon Lee, Chanho Jung, Si-Hwan Jang, Kyung-Ill Kim, Sanghyun Joo, Wook-Ho Son

Abstract:

Since the advances in digital imaging technologies have led to development of high quality digital devices, there are a lot of illegal copies of copyrighted video content on the internet. Thus, we propose a high-quality (HQ) video watermarking scheme that can prevent these illegal copies from spreading out. The proposed scheme is applied spatial and temporal gradient methods to improve the fidelity and detection performance. Also, the scheme duplicates the watermark signal temporally to alleviate the signal reduction caused by geometric and signal-processing distortions. Experimental results show that the proposed scheme achieves better performance than previously proposed schemes and it has high fidelity. The proposed scheme can be used in broadcast monitoring or traitor tracking applications which need fast detection process to prevent illegally recorded video content from spreading out.

Keywords: editing prevention technique, gradient method, luminance change, video watermarking

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356 Enhancing Greenhouse Productivity and Energy Efficiency Through UV-IR Reflective Coatings and Dust Mitigation: A Case Study in Saudi Arabia

Authors: Tayirjan Taylor Isimjan, Essam Jamea, Muien Qaryouti

Abstract:

The demand for efficient greenhouse production is escalating, necessitating continuous improvements in controlled plant growth environments. Central to maximizing growth are critical light-related factors, including quantity, quality, and geometric distribution of intercepted radiation. This becomes particularly crucial in regions like the Middle East, characterized by high solar radiation and dusty atmospheric conditions. Existing greenhouse technologies often rely on additional expensive equipment to manage light conditions effectively. In this study, we propose a distinct approach employing functional coatings to mitigate dust and block UV and IR radiation, thereby conserving energy and enhancing productivity. By combining UV-IR reflective coatings with dust mitigation strategies, we aim to address both environmental challenges and energy consumption issues faced by greenhouse agriculture in Saudi Arabia.

Keywords: greenhouse, UV-IR reflective coatings, dust mitigation, energy efficiency, productivity

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355 Design and Analysis of a Piezoelectric-Based AC Current Measuring Sensor

Authors: Easa Ali Abbasi, Akbar Allahverdizadeh, Reza Jahangiri, Behnam Dadashzadeh

Abstract:

Electrical current measurement is a suitable method for the performance determination of electrical devices. There are two contact and noncontact methods in this measuring process. Contact method has some disadvantages like having direct connection with wire which may endamage the system. Thus, in this paper, a bimorph piezoelectric cantilever beam which has a permanent magnet on its free end is used to measure electrical current in a noncontact way. In mathematical modeling, based on Galerkin method, the governing equation of the cantilever beam is solved, and the equation presenting the relation between applied force and beam’s output voltage is presented. Magnetic force resulting from current carrying wire is considered as the external excitation force of the system. The results are compared with other references in order to demonstrate the accuracy of the mathematical model. Finally, the effects of geometric parameters on the output voltage and natural frequency are presented.

Keywords: cantilever beam, electrical current measurement, forced excitation, piezoelectric

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354 Snake Locomotion: From Sinusoidal Curves and Periodic Spiral Formations to the Design of a Polymorphic Surface

Authors: Ennios Eros Giogos, Nefeli Katsarou, Giota Mantziorou, Elena Panou, Nikolaos Kourniatis, Socratis Giannoudis

Abstract:

In the context of the postgraduate course Productive Design, Department of Interior Architecture of the University of West Attica in Athens, under the guidance of Professors Nikolaos Koyrniatis and Socratis Giannoudis, kinetic mechanisms with parametric models were examined for their further application in the design of objects. In the first phase, the students studied a motion mechanism that they chose from daily experience and then analyzed its geometric structure in relation to the geometric transformations that exist. In the second phase, the students tried to design it through a parametric model in Grasshopper3d for Rhino algorithmic processor and plan the design of its application in an everyday object. For the project presented, our team began by studying the movement of living beings, specifically the snake. By studying the snake and the role that the environment has in its movement, four basic typologies were recognized: serpentine, concertina, sidewinding and rectilinear locomotion, as well as its ability to perform spiral formations. Most typologies are characterized by ripples, a series of sinusoidal curves. For the application of the snake movement in a polymorphic space divider, the use of a coil-type joint was studied. In the Grasshopper program, the simulation of the desired motion for the polymorphic surface was tested by applying a coil on a sinusoidal curve and a spiral curve. It was important throughout the process that the points corresponding to the nodes of the real object remain constant in number, as well as the distances between them and the elasticity of the construction had to be achieved through a modular movement of the coil and not some elastic element (material) at the nodes. Using mesh (repeating coil), the whole construction is transformed into a supporting body and combines functionality with aesthetics. The set of elements functions as a vertical spatial network, where each element participates in its coherence and stability. Depending on the positions of the elements in terms of the level of support, different perspectives are created in terms of the visual perception of the adjacent space. For the implementation of the model on the scale (1:3), (0.50m.x2.00m.), the load-bearing structure that was studied has aluminum rods for the basic pillars Φ6mm and Φ 2.50 mm, for the secondary columns. Filling elements and nodes are of similar material and were made of MDF surfaces. During the design process, four trapezoidal patterns were picketed, which function as filling elements, while in order to support their assembly, a different engraving facet was done. The nodes have holes that can be pierced by the rods, while their connection point with the patterns has a half-carved recess. The patterns have a corresponding recess. The nodes are of two different types depending on the column that passes through them. The patterns and knots were designed to be cut and engraved using a Laser Cutter and attached to the knots using glue. The parameters participate in the design as mechanisms that generate complex forms and structures through the repetition of constantly changing versions of the parts that compose the object.

Keywords: polymorphic, locomotion, sinusoidal curves, parametric

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353 Shock Isolation Performance of a Pre-Compressed Large Deformation Shock Isolator with Quasi-Zero-Stiffness Characteristic

Authors: Ji Chen, Chunhui Zhang, Fanming Zeng, Lei Zhang, Ying Li, Wei Zhang

Abstract:

Based on the synthetic principle of force, a pre-compressed nonlinear isolator with quasi-zero-stiffness (QZS) is developed for shock isolation of ship equipment. The proposed isolator consists of a vertical spring with positive stiffness and several lateral springs with negative stiffness. An analytical expression of vertical stiffness of the nonlinear isolator is derived and numerical simulation on the effect of the geometric design parameters is carried out. Besides, a pre-compressed QZS shock isolation system model is established. The stiffness characteristic of the system is studied and the effects of excitation amplitude and friction damping on shock isolation performance are discussed respectively. The research results show that in comparison with linear shock isolation system, the pre-compressed QZS shock isolation system could realize constant-force or approximately constant-force function and perform better anti-impact performance.

Keywords: quasi-zero-stiffness, constant-force, pre-compressed, large deformation, shock isolation, friction damping

Procedia PDF Downloads 649
352 Fluid Structure Interaction of Flow and Heat Transfer around a Microcantilever

Authors: Khalil Khanafer

Abstract:

This study emphasizes on analyzing the effect of flow conditions and the geometric variation of the microcantilever’s bluff body on the microcantilever detection capabilities within a fluidic device using a finite element fluid-structure interaction model. Such parameters include inlet velocity, flow direction, and height of the microcantilever’s supporting system within the fluidic cell. The transport equations are solved using a finite element formulation based on the Galerkin method of weighted residuals. For a flexible microcantilever, a fully coupled fluid-structure interaction (FSI) analysis is utilized and the fluid domain is described by an Arbitrary-Lagrangian–Eulerian (ALE) formulation that is fully coupled to the structure domain. The results of this study showed a profound effect on the magnitude and direction of the inlet velocity and the height of the bluff body on the deflection of the microcantilever. The vibration characteristics were also investigated in this study. This work paves the road for researchers to design efficient microcantilevers that display least errors in the measurements.

Keywords: fluidic cell, FSI, microcantilever, flow direction

Procedia PDF Downloads 353
351 Three Dimensional Simulation of the Transient Modeling and Simulation of Different Gas Flows Velocity and Flow Distribution in Catalytic Converter with Porous Media

Authors: Amir Reza Radmanesh, Sina Farajzadeh Khosroshahi, Hani Sadr

Abstract:

The transient catalytic converter performance is governed by complex interactions between exhaust gas flow and the monolithic structure of the catalytic converter. Stringent emission regulations around the world necessitate the use of highly-efficient catalytic converters in vehicle exhaust systems. Computational fluid dynamics (CFD) is a powerful tool for calculating the flow field inside the catalytic converter. Radial velocity profiles, obtained by a commercial CFD code, present very good agreement with respective experimental results published in the literature. However the applicability of CFD for transient simulations is limited by the high CPU demands. In the present work, Geometric modeling ceramic monolith substrate is done with square shaped channel type of Catalytic converter and it is coated platinum and palladium. This example illustrates the effect of flow distribution on thermal response of a catalytic converter and different gas flow velocities, during the critical phase of catalytic converter warm up.

Keywords: catalytic converter, computational fluid dynamic, porous media, velocity distribution

Procedia PDF Downloads 828