Bibliografias temáticas / Sma. smat

Índice

Artigos de revistas
Teses / dissertações
Livros
Capítulos de livros
Trabalhos de conferências
Relatórios de organizações

Literatura científica selecionada sobre o tema "Sma. smat"

Autor: Grafiati

Publicado: 19 de outubro de 2024

Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos

Selecione um tipo de fonte:

Consulte a lista de atuais artigos, livros, teses, anais de congressos e outras fontes científicas relevantes para o tema "Sma. smat".

Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.

Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.

Artigos de revistas sobre o assunto "Sma. smat"

Shi, Fei Fei, Bing Hou, Yu Long Li, Jian Lu e Han Zhao. "Experimental Study on a Graded Stainless Steel Sheet under Quasi-Static and Dynamic Loading". Key Engineering Materials 535-536 (janeiro de 2013): 56–59. http://dx.doi.org/10.4028/www.scientific.net/kem.535-536.56.

Texto completo da fonte

Resumo:

Shearing tests and penetration tests were combined to determine the mechanical behavior of a stainless steel metal treated by surface mechanical attrition (SMA). SMAT is a usual treatment to strengthen the hardness of treated surface by severe mechanical strain, which generates also a gradient through the direction of thickness. This paper aimed at investigating the behavior of sheet metals treated by means of SMAT under impact loading. Double shearing tests at high strain rate were performed using Hopkinson bar. The experimental results demonstrated notable strain rate sensitivity and a good ductility without sacrificing the strength. An impact perforation test is also performed using inversed perforation test in order to study its sensibility of failure to the loading rate.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Fitriani, Renita, e Muhammad Tajuddin. "Desain Sistem Informasi Sekolah Berbasis Android". Jurnal Matrik 16, n.º 1 (26 de julho de 2017): 12. http://dx.doi.org/10.30812/matrik.v16i1.19.

Texto completo da fonte

Resumo:

Information technology today has grown rapidly, not least in Indonesia. almost all large and medium enterprises to apply information technology to help oprasi business. The use of thistechnology covers virtually all ages, ranging from young children to adults especially Smart phone. Smart phone is a phone with capabilities beyond computing and connectivity. Smat phonean Android-based smart phone that dominate the world's smart phone market, making the Android-based applications easier when compared to other operating systems. Likewise, the implementation of education, especially Senior High School (SMA). SMAN XXX require the system to help the school and students that there SMAN XXX. Where the application is built withthe programming language PHP (Personal Home Page), Database MySQL, XAMPP, Web Server and its utlity software using android studio. System development methodology that I use is the Waterfall methodology. This system generates data information teacher, student data, employee data, and the data on tuition payments. This application is also in lengakapi with features share the announcement, in which not only the admin can share information or send information, but students, teachers, and employees can also send or transmit information through features share the announcement, which will be received the user a notification announcement, extracurricular andSPP notifications and other announcements.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Rehana, Fowzia, e Afroz Fahmin. "Strategic Management Accounting Techniques of Manufacturing Organizations of Bangladesh With Special Reference to Satisfaction Level". DIU Journal of Business and Entrepreneurship 10, n.º 02 (30 de dezembro de 2016): 123–34. http://dx.doi.org/10.36481/diujbe.v010i2.z8sfje06.

Texto completo da fonte

Resumo:

Different types of business strategy and a number of sophisticated strategy-based techniques have emerged to support and meet the challenges of global competition and customer satisfaction. As a manufacturing organization’s business strategies, such as strategic pattern, strategic mission, and strategic positioning are different- the satisfaction levels of various Strategic Management Accounting Techniques (SMAT) can vary accordingly. This study discussed the degree of similarity and variances of these in listed manufacturing organizations in Bangladesh. Research question of the study is whether relationships between the satisfaction levels of different SMAT and different types of strategic pattern, vision, mission and positioning in listed manufacturing organizations of Bangladesh have been prevailing? Secondary data were collected from 100 listed companies between August and October, 2016. For statistical analysis we used ANOVA test. Out of 16 types of SMAT, none of the techniques found satisfied, few of the techniques are in neutral positions, and most of these are in dissatisfic levels. Study found that the SMAT varies between countries due to economical and cultural differences. Authors found that there is no difference in satisfaction level of different types of SMA techniques identified by the authors based on a previous study. Studics also found that there is significant difference in strategic mission and strategic positioning at 95% confidence interval, respectively.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Demangel, Clémence, A. Poznanski, V. Steenhout, Alexandra Levesque, Hicham Benhayoune e Delphine Retraint. "Benefit of a Surface Nanocrystallization Treatment on Co28Cr6Mo Abrasive Wear Properties". Advanced Materials Research 966-967 (junho de 2014): 435–41. http://dx.doi.org/10.4028/www.scientific.net/amr.966-967.435.

Texto completo da fonte

Resumo:

In this work, the use of a nanocrystallization surface treatment is considered on a cobalt based alloy. Since the Co28Cr6Mo is widely used as an articular bearing surface for artificial joints like hip and knee prostheses, the improvement of its tribological properties is a matter of concern to extend the lifespan of implants. By means of SMA (Surface Mechanical Attrition) treatment, a nanostructured layer is formed at the surface of a CoCrMo alloy establishing an optimized hardness gradient down to a depth of a few hundred of microns. Different treatment times (5, 15 and 25 minutes) are assessed comparatively and several surface polishing methods are studied: with clothes, brushes and a liquid filled with abrasive particles. The influence of processing parameters is discussed regarding hardness and topography. Moreover, the impact of surface modification is examined in terms of wear strengthening through scratch testing. The use of increasing loads mode gives some evidence of the benefit of SMAT. A significant decrease of penetration depth is noticed, from 30% to 60% on average. A straight correlation is also noticed depending on the surface finish method. This study illustrates both the ability of micro scratch testing to assess comparatively treated surface layer and to highlight the benefit of SMAT for wear strengthening in an abrasive wear mode.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Sabora, Ririn S., Astin Lukum, Mardjan Paputungan, Hendri Iyabu, La Ode Aman e La Alio. "Studi Perbandingan Kemampuan Pemecahan Masalah Siswa Menggunakan Model Pembelajaran Problem Based Learning Dan Problem Solving". Jambura Journal of Educational Chemistry 4, n.º 2 (25 de setembro de 2022): 118–26. http://dx.doi.org/10.34312/jjec.v4i2.15781.

Texto completo da fonte

Resumo:

Tujuan penelitian adalah untuk Adapun tujuan dari penelitian ini adalah untuk: Mengetahui perbedaan signifikan antara kemampuan pemecahan masalah siswa yang menerapkan model pembelajaran Problem Based Learning dan Problem Solving di SMAT Wira Bhakti. Desain penelitian yang digunakan adalah Quasi Eksperimental dengan rancangan pretest-posttest control group design. Sampel pada penelitian ini berjumlah 40 siswa yaitu sebanyak 20 siswa pada kelas eksperimen I dan 20 siswa pada kelas eksperimen II. Berdasarkan hasil yang diperoleh dari uji t, nilai thitung sebesar 4,9774 dan nilai ttabel pada taraf α = 0,05; dk = 38 diperoleh sebesar 1,68595. Dengan demikian thitung dilihat lebih besar dari ttabel (thitung = 4,9774 ˃ ttabel =1,68595) sehingga H0 ditolak dengan arti lain bahwa H1 diterima. artinya terdapat adanya perbedaan signifikan antara kemampuan pemecahan masalah siswa pada pokok bahasan hukum-hukum dasar kimia antara kelas yang menerapkan model pembelajaran problem based learning dan kelas yang menerapkan model pembelajaran problem solving di SMA Terpadu Wira Bhakti.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Sakpichaisakul, Kullasate, Kamornwan Katanyuwong, Utcharee Intusoma, Tanitnun Paprad, Piradee Suwanpakdee, Chaiyos Khongkhatithum e Oranee Sanmaneechai. "Spinal muscular atrophy in an upper-middle-income nation before the advent of reimbursed disease-modifying therapies". BMJ Paediatrics Open 8, n.º 1 (agosto de 2024): e002775. http://dx.doi.org/10.1136/bmjpo-2024-002775.

Texto completo da fonte

Resumo:

Objective To elucidate the clinical characteristics and standard of care (SoC) of spinal muscular atrophy (SMA) patients in Thailand, focusing on primary endpoints: age at death and a composite of death or tracheostomy need. Design Retrospective observational study. Setting Seven tertiary centres across Thailand. Patients Records of 110 patients with genetically confirmed SMA, spanning 2012–2021. Interventions Historical data review; no active interventions. Main outcome measures Age at death and a composite measure of death or tracheostomy necessity. Results The cohort included 1 SMA0, 50 SMA1, 40 SMA2 and 19 SMA3 cases. Median ages at the onset and diagnosis of SMA1 were 3 and 6.2 months. Of SMA1 patients, 63% required ventilators, and eight received dimethyltryptamines (DMTs) at a median of 15 months (range 6.4–24.5 months). The median time from onset to DMT was 11 months (range 4.2–20.5 months). Among SMA1 patients, 73% died by the study’s end. SMA2 and SMA3 patients' median onset ages were 11 and 24 months, respectively, with diagnosis at 24.8 and 68.7 months. Half of all types received physical therapy. Conclusions Significant delays in diagnosis and SoC access, including DMTs, were observed, underscoring urgent needs for improved diagnostic and care strategies to enhance SMA patient outcomes in Thailand.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Waltz, Laurent, Delphine Retraint e Arjen Roos. "Semi-Massive Nanocrystallised Composites: From the Process to Mechanical and Microstructural Investigations". Materials Science Forum 762 (julho de 2013): 487–92. http://dx.doi.org/10.4028/www.scientific.net/msf.762.487.

Texto completo da fonte

Resumo:

The aim of the present study is first to describe an original process, the so called duplex process, whose feature is the coupling between the well-known SMAT (Surface Mechanical Attrition Treatment) and the traditional co-rolling. The first step of this process consists of SMA-Treatment of 316L stainless steel sheets to generate nanocrystalline layers on their top surfaces according to the grain refinement mechanism of austenitic steels which is well described in the literature. During the second step, three treated sheets are co-rolled at 550°C to obtain a semi-massive nanocrystallised multilayer structure with improved mechanical strength alternating nanocrystalline, transition and coarse grain layers. The second part of this work deals with the mechanical and the microstructural characterization of the as-obtained structures. Thus, sharp nanoindentation tests performed over the cross section of the laminates coupled with Transmission Electron Microscopy (TEM) confirm the presence of nanograins after the thermomechanical treatment. In addition, the enhanced yield strength demonstrated by tensile tests correlate well with the theoretical volume fractions of nanoand transition layers. The interface cohesion between the sheets is tested by three-point bending tests and the interface bonding is evaluated by microstructural observations.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Wicaksana, Andrean Fahreza Nur, e Akhmad Tabrani. "KEMAMPUAN MENULIS PUISI BERIMA SISWA KELAS X SMA BRAWIJAYA SMART SCHOOL". Hasta Wiyata 6, n.º 2 (30 de julho de 2023): 178–89. http://dx.doi.org/10.21776/ub.hastawiyata.2023.006.02.06.

Texto completo da fonte

Resumo:

The ability to write rhymed poetry is one of the studies that illustrate students' ability to write poetry using the rhyme method. This is important to do because based on observations, students' ability to write poetry is considered lacking. This study aims to determine: 1) the ability of tenth-grade students of SMA Brawijaya Smart School Malang to write rhymed poetry, viewed from the aspect of sound; 2) the ability of tenth-grade students of SMA Brawijaya Smart School Malang to write rhymed poetry, viewed from the aspect of word positioning. The design used in this research is descriptive quantitative, describing the research variables in the form of numbers or statistics obtained from written test results that portray the ability of tenth-grade students of SMA Brawijaya Smart School Malang to write a rhymed poem. The data in this study was analyzed through five stages: collecting data, identifying data, classifying data, analyzing data, and drawing conclusions. The data processing results in this study show that the ability of tenth-grade students of SMA Brawijaya Smart School Malang to write rhymed poetry is already adequate. Based on the data processing results, it appears that the test results of the tenth-grade students of SMA Brawijaya Smart School Malang in writing rhymed poetry are categorized as good with an average score of 88.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Septiana, Santi, Fahyuddin Fahyuddin e Nur Arfa Yanti. "ANALISI FAKTOR – FAKTOR YANG MEMPENGARUHI PRESTASI BELAJAR BIOLOGI : STUDI KASUS PADA SISWA KELAS XI SMA DI KABUPATEN MOROWALI". Jurnal Biofiskim: Pendidikan dan Pembelajaran IPA 3, n.º 1 (30 de junho de 2021): 33. http://dx.doi.org/10.33772/biofiskim.v3i1.23525.

Texto completo da fonte

Resumo:

Abstrak. Tujuan penelitian ini adalah untuk mempelajari Pengaruh Lingkungan Keluarga, Lingkungan Sekolah, Minat Dan Motivasi Belajar Terhadap Prestasi Belajar Biologi Pada Siswa SMA Se-Kabupaten Morowali. Jenis penelitian ini adalah korelasi sebab akibat. Teknik pengambilan data menggunakan kuesioner dan dokumentasi. Populasi dalam penelitian ini berjumlah 2.630 siswa dan sampel berjumlah 169 siswa dengan teknik cluster stratified random sampling yang berasal dari siswa kelas XI IPA dari SMAN 1 Witaponda, SMAN 2 Bungku, SMAN 1 Menui Kepulauan, SMAS Al-Khairaat Kolono dan SMAN 1 Bungku Pesisir. Teknik analisis menggunakan teknik analisis jalur. Hasil penelitian menunjukkan bahwa variabel eksternal lingkungan keluarga dan lingkungan sekolah siswa SMA sekabupaten Morowali masih tergolong sedang secara rata. Lingkungan keluarga, lingkungan sekolah, minat, dan motivasi secara bersama sama memberikan pengaruh yang signifikan pada prestasi belajar biologi sebesar 24% dan sisanya 76% di pengaruhi oleh faktor lain. Kata Kunci: lingkungan keluarga, lingkungan sekolah, minat, motivasi dan prestasi belajar

Estilos ABNT, Harvard, Vancouver, APA, etc.

Hasnat, Abul, Safkat Tajwar Ahmed e Hafiz Ahmed. "A Review Of Utilizing Shape Memory Alloy In Structural Safety". AIUB Journal of Science and Engineering (AJSE) 19, n.º 3 (31 de dezembro de 2020): 116–25. http://dx.doi.org/10.53799/ajse.v19i3.111.

Texto completo da fonte

Resumo:

Abstract- The advancement of material technology has paved the way for smart materials to emerge in the civil engineering sector. These smart materials possess the potential to encounter structural deterioration. Therefore, proper attention should be provided to smart materials regarding both research and application. Shape memory alloy (SMA) is a unique smart material that demonstrates growing applicability in numerous sectors. Recently, a lot of emphasis is being given to SMA research with a view to utilizing SMA in civil engineering structures. SMAs have some special properties such as high damping capacity, self-centering mechanism, two-way memory, self-adaptability etc. for which they can be used to make various types of structural control devices. An integrated assessment of the fundamental properties of SMAs, based on the existing data is presented by this paper in a concise and graphical manner. This paper also discusses the possibility of implementing SMAs in a wide range of civil engineering application, therefore motivating the large scale development of smart structures.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Mais fontes

Teses / dissertações sobre o assunto "Sma. smat"

Gasmi, Assia. "Effet de la nanostructuration sur le comportement thermomécanique du Nitinol". Electronic Thesis or Diss., Université de Montpellier (2022-....), 2024. http://www.theses.fr/2024UMONS018.

Texto completo da fonte

Resumo:

La présente thèse s’intéresse à l'alliage à mémoire de forme NiTi, en se concentrant sur l'influence du procédé de nanostructuration superficielle SMAT sur son comportement thermomécanique. À travers quatre chapitres distincts, elle rappelle les principales caractéristiques des alliages à mémoire de forme (AMF), mettant en avant les propriétés exceptionnelles de l'alliage NiTi, et explorant le traitement de nanocristallisation superficielle (SMAT). La caractérisation microstructurale est ensuite approfondie, notamment en étudiant les effets du traitement thermique de recuit et du SMAT sur la transition de phase. Le troisième chapitre se concentre sur les méthodes d'analyse thermomécanique adaptées au NiTi, en examinant les essais de traction et de nanoindentation. Enfin, le quatrième chapitre analyse la caractérisation thermomécanique de l'alliage avant et après le traitement SMAT, mettant en évidence les implications de ces transformations sur son comportement global.La thèse contribue à la compréhension des effets du procédé SMAT sur l'alliage NiTi, révélant des liens entre la microstructure, les phases présentes et les propriétés mécaniques. Les résultats ouvrent des perspectives prometteuses pour la meilleure maîtrise des propriétés de l'alliage NiTi.Les résultats obtenus pour différents traitements SMAT montrent que ce procédé modifie la réponse mécanique du matériau. Elle a aussi une influence sur son état initial, comme l’illustrent les différences dans les courbes de DSC. Les mesures cinématiques (champs de vitesses de déformation) et calorimétriques (champ de source de chaleur) indiquent aussi l’apparition de différences notables dans les réponses en fonction des paramètres de traitement SMAT. L'exploration du comportement lors de cycles de charge/décharge montre une réponse qui se stabiliser après quelques cycles. Les effets de couplage semblent être prépondérants par rapport aux effets dissipatifs. Ces observations devraient être étendues à des chargements en fatigue afin de mieux mettre en évidence les éventuels effets dissipatifs. De même, l’utilisation de modèles d’interprétation plus élaborés permettrait de mieux tenir compte des effets de structure et d’enrichir la compréhension de la relation entre le procédé et les évolutions des propriétés
This thesis focuses on the shape memory alloy NiTi, with a specific emphasis on the influence of the surface nanostructuring process SMAT on its thermomechanical behavior. Through four distinct chapters, it revisits the main characteristics of shape memory alloys (SMAs), highlighting the exceptional properties of the NiTi alloy and exploring the surface nanocrystallization treatment (SMAT). Microstructural characterization is then deeply investigated, particularly by studying the effects of annealing heat treatment and SMAT on phase transition. The third chapter focuses on thermomechanical analysis methods suitable for NiTi, examining tensile tests and nanoindentation. Finally, the fourth chapter analyzes the thermomechanical characterization of the alloy before and after SMAT treatment, highlighting the implications of these transformations on its overall behavior.This thesis contributes to understanding the effects of the SMAT process on the NiTi alloy, revealing links between microstructure, present phases, and mechanical properties. The results offer promising perspectives for better control of the properties of the NiTi alloy.The results obtained for different SMAT treatments show that this process modifies the mechanical response of the material. It also has an influence on its initial state, as illustrated by differences in DSC curves. Kinematic (strain rate fields) and calorimetric (heat source field) measurements also indicate notable differences in responses depending on SMAT processing parameters. Exploration of behavior during load/unload cycles shows a response that stabilizes after a few cycles. Coupling effects seem to be predominant compared to dissipative effects. These observations should be extended to fatigue loading to better highlight any dissipative effects. Similarly, the use of more elaborate interpretation models would allow better consideration of structural effects and enrich the understanding of the relationship between the process and property evolutions

Estilos ABNT, Harvard, Vancouver, APA, etc.

Grimslätt, Tove, e Sofia Freiholtz. "SMAX : Smart clothing racks". Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-37531.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Anjum, Sadaf Saad. "Fabrication of smart intercalated polymer-SMA nanocomposite". Thesis, Cranfield University, 2015. http://dspace.lib.cranfield.ac.uk/handle/1826/9384.

Texto completo da fonte

Resumo:

Mimicking nature gives rise to many important facets of biomaterials. This study is inspired by nature and reports on the fabrication of an intercalated polymer-NiTi nanocomposite that mimics the structural order of urethral tissue performing micturition. PTFE is chosen due to its hydrophobicity, low surface energy, and thermal and chemical stability. NiTi has been selected as a prime candidate for this research due to its excellent mechanical stability, corrosion resistance, energy absorbance, shape memory and biocompatibility. Nanoscale engineering of intercalated nanocomposites is done by PVD sputtering PTFE and NiTi. FTIR spectroscopy confirms that PTFE reforms as polymer chains after sputtering. Suitable PVD sputtering parameters were selected by investigating their influence on deposition rates, microstructure and properties of PTFE and NiTi thin films. PTFE forms stable nanocomposite coatings with NiTi and displays favourable surface interactions, known as ‘intercalation’. Intercalated PTFE-NiTi films were fabricated as layered and co-sputtered thin films. Co-sputtered nanocomposites contained nearly one-third vacant sites within its internal microstructure because of intercalation while intercalation introduced minute pits in fibrous NiTi columns of layered nanocomposites. These pits allow PTFE to extend their chains and crosslinks, resulting in microstructural and functional changes in the thin films. Intercalated PTFE-NiTi nanocomposites offer a close match to the natural tissue in terms of responding to the fluid contact (wetting angle modifications), and allow the soft and hard matter to incorporate in one framework without any chemical reactions (intercalation). An intercalated microstructure in co-sputtered and layered nanocomposites was verified by EDS-SEM and EDS-TEM techniques. The functional responses were witnessed by changes in water contact angle (WCA) and coefficient of friction (CoF) values measured on the film surface. The WCA (99°) and CoF (0.1 – 0.2) of the intercalated nanocomposite (sample PNT12) were different to the NiTi (top layer). WCA and CoF indicate the internal microstructural interactions because of intercalation. Although the pseudoelastic behaviour of NiTi can provide additional fluid response but the difficulty is an absence of crystallinity in as-deposited NiTi, and the heat treatment that melts PTFE. However, DSC and XRD techniques were employed to find the optimum NiTi composition and transition temperatures for phase transformation related to pseudoelasticity. This study provides the basis to incorporate the shape memory (pseudoelasticity or thermal shape memory effect (shape memory effect)) features of NiTi into the intercalated nanocomposite in future. The intercalated PTFE-NiTi nanocomposite reveals a fascinating research precinct, having the response generating characteristics similar to that of natural tissue.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Hassan, Mohd Roshdi. "Design, manufacturing and testing of SMA-based smart and cellular structures". Thesis, University of Sheffield, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434620.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Alazzawi, Sheymaa. "DESIGNING A SMART GREENHOUSE VENTILATION WINDOW BASED ON NITI SMA ACTUATOR". OpenSIUC, 2019. https://opensiuc.lib.siu.edu/dissertations/1703.

Texto completo da fonte

Resumo:

A multi-functional (sensing -actuating) greenhouse ventilation window heated/cooled naturally by convection was designed to overcome different industry challenges in terms of designing smart applications. This ventilation window design includes a three-pulley system to reduce the load on the NiTi actuator and enhance its long-life time. In addition, using the NiTi actuator allows energy saving due to natural phase transformation induction (i.e. convection) and high force generation compared to the small NiTi wire mass. Structural analysis was used to determine the force generated in the “C-shaped” NiTi wire after loading. Transient thermal and structural analysis also was used to investigate the strain rate effects on the shape memory response of “C shaped” NiTi alloy element under different thermomechanical loadings and boundary conditions. Two types of loading have been applied isothermally or at adiabatic conditions. The results showed a significant effect of the high loading rates on increasing the stress plateau which is caused by the corresponding shift in the transformation temperatures. As a result, it could be expected that the actuator life time could be reduced when a rapid, as opposed to a slow loading rate, is adopted. In addition, the dynamic loading of the NiTi leads to a decrease of the recoverable strain. Experimental work was done to validate the simulation model by testing a commercial NiTi sample dynamically and compare the macroscopic displacement during mechanical loading and the strain recovery process.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Vouillot, Léna. "Développement des motoneurones chez un modèle amphibien d'amyotrophie spinale généré à l'aide de nucléases". Thesis, Evry-Val d'Essonne, 2014. http://www.theses.fr/2014EVRY0038.

Texto completo da fonte

Resumo:

Les amyotrophies spinales proximales sont des maladies génétiques neuromusculaires caractérisées par la dégénérescence des motoneurones spinaux et une atrophie des muscles squelettiques proximaux. La perte de fonction du gène smn1, un gène essentiel à la survie des motoneurones, entraîne une réduction drastique du niveau de protéine SMN et est, à l’origine des symptômes observés chez les patients. L'amphibien anoure Xenopus tropicalis constitue un très bon petit animal modèle pour étudier cette maladie ainsi que le développement des motoneurones. En effet une diminution de la production de la protéine SMN via l’utilisation de morpholinos a permis de montrer chez les têtards, des défauts de migration des motoneurones ainsi qu’une atrophie des muscles caudaux. Pour développer un modèle héritable de SMA, nous avons utilisé des nucléases tels que les ZFN ou le système CRISPR/Cas pour générer des mutations du gène smn chez Xenopus tropicalis. Nous avons conçu les outils moléculaires pour induire différentes mutations du gène smn avec des ZFN ou le système CRISP/Cas9. Nous avons ensuite validé l'efficacité de ces nucléases dans des embryons in vivo et développé une méthode de recherche de mutations basée sur l’utilisation des endonucléases T7EI et Surveyor. Nous avons obtenu un animal fondateur mutant qui permettra de générer des embryons homozygotes pour la mutation. En parallèle, nous avons développé une lignée transgénique chez Xenopus tropicalis permettant de visualiser les populations de motoneurones spinaux, pour mieux caractériser les animaux mutants smn in vivo. La combinaison de ces deux lignées permettra de mieux comprendre la physiopathologie motoneuronal liée à des mutations de smn
Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by motor neuron loss and skeletal muscle atrophy. In human the loss of function of the smn1 gene, the main supplier of survival motor neuron protein (SMN), leads to reduced levels of SMN and eventually to SMA. The anuran amphibian Xenopus tropicalis is a good animal model for the study of SMA and motor neurons development. Indeed the inhibition of the production of SMN using antisense morpholinos leads to caudal muscular atrophy in tadpoles. To develop an inheritable SMA model, we edited the smn gene in X. tropicalis using zinc-finger nucleases (ZFNs) and CRISPR/Cas system. As a first step, we designed the molecular tools needed to induce mutations of the smn gene using ZFN and CRISPR/cas9. Next we probed the efficiency of these tools and developed a method to identify mutations using T7EI and Surveyor endonucleases. We obtained a mutant frog and thus we will be able to produce homozygous mutant embryos for smn. In parallel we developed a transgenic line of Xenopus tropicalis frogs in which we can image motor neurons populations in vivo. The combination of both lines should enable to increase our knowledge and understanding of motor neuron physiopathology due to smn mutations

Estilos ABNT, Harvard, Vancouver, APA, etc.

Demény, Maté Agoston. "Analysis of TAF8, a subunit of TFIID and SMAT (smal TAF complex), reveals novel regulation of the assembly of TAF-containing complexes". Université Louis Pasteur (Strasbourg) (1971-2008), 2006. http://www.theses.fr/2006STR13096.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Alhali, Sara. "Formminneslegeringar : En jämförandestudie mellan en ny typ av förstärkning och traditionella förstärkning av broar". Thesis, Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-45391.

Texto completo da fonte

Resumo:

Den industriella revolutionen kom med behovet av att bygga byggnader och broar, till en början förstod man inte vikten av armering och förstärkning av konstruktion. Men med tiden behövde man komma på någon strategi att göra konstruktionen starkare och mer hållbar, och det var då man började använda sig av förstärkning. I dagens moderna samhälle är det vanligare att bygga med betong, betong är det viktigaste byggmaterialet i världen. Det har flera egenskaper som garanterar en lång livslängd för konstruktionen; dess hållbarhet och styvhet är av störst intresse för att designa betongkonstruktioner. Andra egenskaper såsom täthet och bearbetbarhet är också viktiga. För att utnyttja betongegenskaperna korrekt måste nästan alla strukturer förstärkas på ett eller annat sätt. Därför har man under en lång period gjort stora forskningar på hur man kan göra betong starkt i draghållfasthet och inte bara i tryck. Moderna komplicerade konstruktionsformer kräver nya förstärkningsmetoder, komplexiteten i den nya strukturen både när det gäller höjd och bredd har nödvändiggjort behovet av nya metoder för betongarmering. En metod är användningen av järn-baserade minneslegeringar (Fe-SMA), genom forskning har det visat sig vara en effektiv metod för armering av stål. SMAs har unika egenskaper och det mest speciella är att det återgår till sin ursprungliga form även när det har deformerats. Som ett resultat av detta möjliggör det förstärkning av betong av vilken form och storlek som helst, de goda limegenskaperna hos betong och järn gör installationen komplett. Detta examensarbete resulterade att SMA har väldigt unika egenskaper som kommer att göra stora skillnader i byggbranschen. Detta gäller främst hos broar och är en väldigt aktuell metod som har förmågan att anpassa sig till den omgivande miljön. Utöver det kan den även justera sig själv för att säkerställa optimal och säker drift under normala och svåra belastnings villkor och det minimala kravet för underhåll.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Hu, Jong Wan. "Seismic performance evaluations and analyses for composite moment frames with smart SMA PR-CFT connections". Diss., Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22655.

Texto completo da fonte

Resumo:

This thesis investigates the performance of composite frame structures with smart partially-restrained (PR) concrete filled tube (CFT) column connections through simplified 2D and advanced 3D computational simulations. It also provides a design methodology for new types of innovative connections based on achieving a beam hinging mechanism. These types of connections intend to utilize the recentering properties of super-elastic SMA tension bars, the energy dissipation capacity of low-carbon steel bars, and the robustness of CFT columns. In the first part of this study, three different PR-CFT connection prototypes were designed based on a hierarchy of strength models for each connection component. Numerical simulations with refined three dimensional (3D) solid elements were conducted on full scale PR-CFT connection models in order to verify the strength models and evaluate the system performance under static loading. Based on system information obtained from these analyses, simplified connection models were formulated by replacing the individual connection components with spring elements and condensing their contributions. Connection behavior under cyclic loads was extrapolated and then compared with the monotonic behavior. In the second part of this study, the application of these connections to low-rise composite frames was illustrated by designing both 2D and 3D, 4 and 6 story buildings for the Los Angeles region. A total of 36 frames were studied. Pushover curves plotted as the normalized shear force versus inter story drift ratio (ISDR) showed significant transition points: elastic range or proportional limit, full yielding of the cross-section, strength hardening, ultimate strength, and strength degradation or stability limit. Based on the transition points in the monotonic pushover curves, three performance levels were defined: Design Point, Yield Point, and Ultimate Point. All frames were stable up to the yield point level. For all fames, after reaching the ultimate point, plastic rotation increased significantly and concentrated on the lower levels. These observations were quantified through the use of elastic strength ratios and inelastic curvature ductility ratios. The composite frames showed superior performance over traditional welded ones in terms of ductility and stability, and validated the premises of this research.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Henriques, Moreira Daniel. "SimPatrol: um simulador de sistemas multiagentes para o patrulhamento". Universidade Federal de Pernambuco, 2008. https://repositorio.ufpe.br/handle/123456789/2248.

Texto completo da fonte

Resumo:

Made available in DSpace on 2014-06-12T15:55:45Z (GMT). No. of bitstreams: 2 arquivo2286_1.pdf: 1818614 bytes, checksum: bde38ef39500718996aa2511dab57905 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Apesar de sistemas multiagentes estarem se tornando cada vez mais comuns no desenvolvimento de software, há ainda que se chegar a um consenso sobre como modelar e comparar diferentes soluções de sistemas multiagentes para um mesmo problema. Em outras palavras, os pesquisadores de tal área ainda estão à procura de benchmarks que sirvam de referência para a comparação de abordagens distintas. Dada a importância do estabelecimento de benchmarks para sistemas multiagentes, uma questão que surge entre os pesquisadores da área de patrulhamento é a possibilidade e o potencial do problema do patrulhamento como um destes benchmarks. Apesar da quantidade de trabalho produzido até este ponto, tem-se encontrado dificuldades para comparar precisamente as soluções propostas para o patrulhamento. Estas dificuldades remetem principalmente à ausência de ferramentas (em especial um simulador unificado) que permitam aos estudiosos se concentrarem na solução do problema em si, e não na sua representação. Partindo deste cenário, este trabalho tem como objetivo discutir o estabelecimento do patrulhamento enquanto um benchmark para sistemas multiagentes. Adicionalmente, como um primeiro passo no sentido de preencher as lacunas que dificultam tal estabelecimento, introduz-se o SimPatrol, um novo simulador voltado para a tarefa de patrulhamento, fortemente inspirado pelos simuladores da RoboCup e TAC. Novos resultados são produzidos a partir de uma avaliação de parte das técnicas propostas pelas pesquisas anteriores frente às novas funcionalidades implementadas pelo simulador, em especial a inédita medida de ociosidade dos vértices, que leva em consideração o tempo de raciocínio gasto pelos patrulheiros

Estilos ABNT, Harvard, Vancouver, APA, etc.

Mais fontes

Livros sobre o assunto "Sma. smat"

Kaisha, Fuji Terebijon Kabushiki, ed. Bisutoro Sumappu kanzen reshipi: Bistro Smap = Smap x Smap. Tōkyō: Fuji Terebi Shuppan, 1996.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

1967-, Klu-byams-rgyal Bya-mdo, e Lha-mo-skyabs, eds. Bod sman sman sbyor rig pa. [Pe-cin]: Mi rigs dpe skrun khaṅ, 2007.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Foitzik, Jan, Horst Möller, Wladimir P. Koslow, Alexandr O. Tschubarjan, Sergei W. Mironienko e Hartmut Weber, eds. SMAD-Handbuch. München: OLDENBOURG WISSENSCHAFTSVERLAG, 2009. http://dx.doi.org/10.1524/9783486708578.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Madzelan, Seman. Smak doli. [Nowy Sącz]: Sądecka Oficyna Wydawnicza, 1986.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Cetera, A. Smak morwy. Warszawa: Wyd-wo Uniw. Warszawskiego, 2009.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Mozdzynski, Tadeusz. Smak Chleba. Krakow: Wyd. Literackie, 1985.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Polska, Edipresse, ed. Smak miłości. Warszawa: Wydawnictwo Edipresse Polska, 2013.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Henadzʹ, Kisi︠a︡li︠o︡ŭ, ed. Smak Belarushchyny. Minsk: Limaryus, 2013.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Madzeli͡an, Semen. Smak doli. Nowy Sącz: Sądecka Oficyna Wydawnicza Woj. Ośrodka Kultury, 1986.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Wernik, Romuald. Smak miodu. Poznań: Wydawn. 'Kurpisz", 1994.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Mais fontes

Capítulos de livros sobre o assunto "Sma. smat"

Gooch, Jan W. "SMA". In Encyclopedic Dictionary of Polymers, 672. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_10781.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Ahmadian, Amir, Angela E. Downes e A. Samy Youssef. "SMA". In Encyclopedia of Otolaryngology, Head and Neck Surgery, 2518. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-23499-6_200114.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Leung, Alexander K. C., Cham Pion Kao, Andrew L. Wong, Alexander K. C. Leung, Thomas Kolter, Ute Schepers, Konrad Sandhoff et al. "SMA". In Encyclopedia of Molecular Mechanisms of Disease, 1946. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-29676-8_6849.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Kohl, Manfred. "SMA Microvalves". In Microtechnology and MEMS, 96–160. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-662-09875-2_5.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Langbein, Sven, e Alexander Czechowicz. "Future Perspectives of SMA and SMA Valves". In Shape Memory Alloy Valves, 191–207. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-19081-5_12.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Revertera, Jean, Maria Sokhn, Elena Mugellini e Omar Abou Khaled. "SMAC: Smart Multimedia Archiving for Conferences". In Advances in Intelligent and Soft Computing, 143–52. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-18029-3_15.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Li, Chuanyang, Dewei Tang, Hongwei Guo, Huiyin Yan, Weimin Ouyang, Rongqiang Liu e Zongquan Deng. "Parameters Analysis of SMA Bimetallic Strip Smart Actuator". In Advances in Mechanism and Machine Science, 2599–609. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-20131-9_257.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Kohl, Manfred, Berthold Krevet e Elmar Just. "SMA Microgripper System". In Transducers ’01 Eurosensors XV, 710–13. Berlin, Heidelberg: Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/978-3-642-59497-7_169.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Andani, Masood Taheri, Francesco Bucchi e Mohammad H. Elahinia. "SMA Actuation Mechanisms". In Shape Memory Alloy Actuators, 85–123. Chichester, UK: John Wiley & Sons, Ltd, 2015. http://dx.doi.org/10.1002/9781118426913.ch3.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Kohl, Manfred. "SMA Linear Actuators". In Microtechnology and MEMS, 161–218. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-662-09875-2_6.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Trabalhos de conferências sobre o assunto "Sma. smat"

Bruck, Hugh A., e Charles L. Moore. "Mechanical Characterization of Shape Memory Alloy Composites for Designing Smart Structures". In ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-0532.

Texto completo da fonte

Resumo:

Abstract Actuators with large displacement ranges are being designed for smart structures by utilizing the unconventional mechanical behavior of Shape Memory Alloys (SMAs). This behavior is characterized by deformation recovery through thermally activated phase transformations. However, because of this deformation mechanism, conventional constitutive models cannot be employed to predict the mechanical behavior of SMAs. Appropriate constitutive models have been proposed, but their application can be computationally intensive. In this investigation, SMA wire-reinforced fiberglass composites are fabricated to determine the relationship between the mechanical response of the composite and the composition of SMA wire reinforcement. A modified linear Rule-of-Mixtures (ROM) formulation is proposed for predicting the mechanical behavior of the SMA composites. This simple, uniaxial constitutive model provides a reasonable prediction of SMA composite mechanical behavior, and is computationally efficient enough to use with Finite Element Analyses for designing smart structures that contain heterogeneous compositions.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Xu, Lei, Theocharis Baxevanis e Dimitris Lagoudas. "A Three-Dimensional Constitutive Model for Polycrystalline Shape Memory Alloys Under Large Strains Combined With Large Rotations". In ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/smasis2018-8050.

Texto completo da fonte

Resumo:

Shape Memory Alloys (SMAs), known as an intermetallic alloys with the ability to recover its predefined shape under specific thermomechanical loading, has been widely aware of working as actuators for active/smart morphing structures in engineering industry. Because of the high actuation energy density of SMAs, compared to other active materials, structures integrated with SMA-based actuators has high advantage in terms of tradeoffs between overall structure weight, integrity and functionality. The majority of available constitutive models for SMAs are developed within infinitesimal strain regime. However, it was reported that particular SMAs can generate transformation strains nearly up to 8%–10%, for which the adopted infinitesimal strain assumption is no longer appropriate. Furthermore, industry applications may require SMA actuators, such as a SMA torque tube, undergo large rotation deformation at work. Combining the above two facts, a constitutive model for SMAs developed on a finite deformation framework is required to predict accurate response for these SMA-based actuators under large deformations. A three-dimensional constitutive model for SMAs considering large strains with large rotations is proposed in this work. This model utilizes the logarithmic strain as a finite strain measure for large deformation analysis so that its rate form hypoelastic constitutive relation can be consistently integrated to deliver a free energy based hyper-elastic constitutive relation. The martensitic volume fraction and the second-order transformation strain tensor are chosen as the internal state variables to characterize the inelastic response exhibited by polycrystalline SMAs. Numerical experiments for basic SMA geometries, such as a bar under tension and a torque tube under torsion are performed to test the capabilities of the newly proposed model. The presented formulation and its numerical implementation scheme can be extended in future work for the incorporation of other inelastic phenomenas such as transformation-induced plasticity, viscoplasticity and creep under large deformations.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Daghash, Sherif, Osman E. Ozbulut e Muhammad M. Sherif. "Shape Memory Alloy Cables for Civil Infrastructure Systems". In ASME 2014 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/smasis2014-7562.

Texto completo da fonte

Resumo:

Shape memory alloys (SMAs) have attracted a great deal of attention as a smart material that can be used in various civil engineering applications due to their favorable mechanical properties such as ability to undergo large deformations, high corrosion and fatigue resistance, good energy dissipating capacity, and excellent re-centering ability. In contrast to the use of SMAs in the biomedical, mechanical and aerospace applications, which requires mostly small diameter of material, the larger size bars are usually needed in a civil engineering application. It is well known that properties of large-section SMA bars are generally poorer than those of wires due to difficulties in material processing. Furthermore, large diameter SMA bars are more expensive than thin SMA wires. Shape memory alloy cables have been recently developed as an alternative and new structural element. They leverage the superior mechanical characteristics of small diameter SMAs into large-size structural tension elements and possess several advantages over SMA bars. This study explores the performance of NiTi SMA cables and their potential use in civil engineering. The SMA cable, which has a diameter of 8 mm, is composed of 7 strands and each strand has 7 wires with a diameter of 0.885 mm. The uniaxial tensile tests are conducted at various loading rates and strain amplitudes to characterize the superelastic properties of the SMA cable and study the rate-dependent mechanical response of the SMA cable under dynamic loads. An optical digital image correlation measurement system and an infrared thermal imaging camera are employed to obtain the full-field strain and temperature fields. Potential applications of SMA cables in civil infrastructure applications are discussed and illustrated.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Bruck, Hugh A., e Charles L. Moore. "Mechanical Characterization and Design of Shape Memory Alloy Composites for Functionally Graded Adaptive Structures". In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1695.

Texto completo da fonte

Resumo:

Abstract Shape Memory Alloys (SMAs) are being embedded in smart structures for sensing and actuation. The resulting structure is a composite material that possesses a heterogeneous architecture, requiring a system-based approach to optimize its design. In order to develop this approach, it is necessary to determine appropriate thermomechanical models for designing heterogeneous smart structures. In this investigation, the constitutive and actuation behavior of SMA wire-reinforced epoxy composites are charaacterized. A structural model is then verified for predicting the actuation behavior of functionally graded adaptive structures fabricated from SMA composites.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Šittner, P., V. Novák, P. Lukáš e D. Neov. "Stress Induced Martensitic Transformation in Shape Memory Alloys Studied by In-Situ Neutron Diffraction Techniques". In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1686.

Texto completo da fonte

Resumo:

Abstract Shape memory alloy (SMA) elements are being embedded in smart materials and hybrid composites as actuating and/or sensing elements responding to the stress and temperature stimuli. In order to design smart composites, in-situ experimental information about evolution of internal stresses and phase fractions in the embedded SMA elements and internal stresses in neighboring matrix during actuation cycles would be of interest. Such experimental data have to be obtained nondestructively from the microscopic particles or fibres deep in the bulk specimens exposed to stress and/or thermal variations. In-situ neutron diffraction experimental techniques fulfill in principle these requirements. However, reliable evaluation of internal stresses from neutron diffraction experiments in the smart SMA composites can be made only after the lattice plane responses of monolithic SMAs in thermomechanical cyclic loads are fully understood. In this paper, the results of the in-situ investigations of stress induced martensitic transformation (SIMT) in tensile tests carried out on monolithic CuAlZnMn SMA polycrystal are reported, and the observed lattice plane responses are interpreted using a selfconsistent model of SMA polycrystal.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Park, Jungkyu, Leon M. Headings, Marcelo J. Dapino, Jeffery W. Baur e Gyaneshwar P. Tandon. "Analysis of Shape Memory Polymer-Alloy Composites: Modeling and Parametric Studies". In ASME 2012 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/smasis2012-8257.

Texto completo da fonte

Resumo:

Shape memory composites (SMCs) based on shape memory alloys (SMAs) and shape memory polymers (SMPs) are interesting due to their controllable temperature-dependent mechanical properties. The complementary characteristics of SMAs and SMPs can be used to create materials or systems with shape recovery created by the SMA and shape fixity provided by the SMP. In this research, three SMC operating regimes are identified and the behavior of SMC structures is analyzed by focusing on composite fixity and interfacial stresses. Analytical models show that certain SMPs can achieve sufficient shape fixing. COMSOL Multi-Physics simulations are in agreement with analytical expressions for shape fixity and interfacial stresses. Analytical models are developed for an end-coupled linear SMP-SMA two-way actuation system.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Jia, Hongyu, Frederic Lalande e Craig A. Rogers. "Review of Constitutive Modeling of Shape Memory Alloys". In ASME 1996 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/imece1996-0673.

Texto completo da fonte

Resumo:

Abstract Shape memory alloys (SMAs) are increasingly used in many engineering fields, particularly in the smart or intelligent material area. The principal characteristic of shape memory alloys is their ability to memorize their original configuration after they have been deformed, by heating the alloys above the characteristic transition temperature. During this process, a large recoverable strain on the order of 8% can be obtained, making SMAs excellent actuators. In order to fully utilize the SMAs potential, it is necessary to have a good understanding of their mechanical behavior under thermal and mechanical loading. For this reason, the constitutive modeling of SMA has been, and still is, the focus of many researchers. Several models based on various theories have been proposed thus far. Considering the various theories used, the proposed constitutive models can be classified to five categories: ferroelectrics models, internal variable models, plasticity models, hysteresis models, and non-isothermal models. A review of the SMA constitutive models is presented here.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Prechtl, Johannes, Stefan Seelecke, Paul Motzki e Gianluca Rizzello. "Self-Sensing Control of Antagonistic SMA Actuators Based on Resistance-Displacement Hysteresis Compensation". In ASME 2020 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/smasis2020-2224.

Texto completo da fonte

Resumo:

Abstract Shape memory alloys (SMAs) are a well-known class of smart materials which allow the design of compact and silent actuation mechanisms. A remarkable feature of SMAs is self-sensing, namely the possibility to reconstruct the actuator position information from electrical resistance measurements. In case of simple SMA actuators, such as spring-loaded wires, the relation between resistance and displacement is usually linear and thus simple to exploit for self-sensing. For more advanced actuator types, such as protagonist-antagonist SMA configurations, the resistance-displacement characteristic is often hysteretic and thus more difficult to invert in real-time. To deal with this issue, this work proposes a novel self-sensing method for protagonist-antagonist SMA actuators having a highly hysteretic resistance-displacement behavior. An online hysteresis compensation scheme, based on the modified Prandtl-Ishlinskii model, is implemented and used to linearize the resistance-displacement characteristic. A lab setup which allows characterization of antagonistic SMA system as well as implementation of self-sensing control architectures is also developed. Experimental results show how, when combined with a PI controller, the developed scheme permits to noticeably reduce the error in comparison to compensator-free self-sensing architectures.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Lara-Quintanilla, Adrian, e Harald E. N. Bersee. "Improvement of the Attainable Working Frequency of SMA Wires by Means of Active Cooling and Working Strain-Ratios". In ASME 2014 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/smasis2014-7464.

Texto completo da fonte

Resumo:

Shape Memory Alloys (SMAs) are one of the most widely used smart materials. Their attractive characteristics make them interesting for the development of novel devices. Most of these devices make use of their shape memory effect or superelasticity; these effects are based on diffusionless phase transitions. SMAs can be used in different forms. In particular, wires are often used for actuation purposes because they exert linear forces and large strokes, up to the 8% of their original (memorized) length. However, they work at very low frequencies. SMAs are thermally activated. The limitation on their actuation bandwidth is a consequence of their capability to increase and decrease their temperature. The most common way of heating SMA wires is by Joule heating. Afterwards, they normally cool down by releasing thermal energy to their surroundings by conduction or convection. The heating and the cooling come from different physic’s principles and the cooling is a slower process than the heating one. Therefore, the cooling of SMAs is the main concern regarding to the SMA wire’s maximum attainable working frequency. In this paper, the effect of different applied heating and cooling rates on the resulting SMA wire’s working frequency is studied. Different heating rates have been applied to an SMA wire by applying different levels of electrical power. In a similar manner, different cooling rates have been applied to the wire by applying different forced airflows around the SMA wire. The use of a forced airflow has shown to increase the convective heat transfer coefficient between the wire and the surrounding air up to eight-fold. SMA wires’ working frequency depends on the amplitude of strains at which it performs. The higher the amplitude, the lower the maximum attainable frequency. Moreover, the relationship between the temperature and the strain is highly non-linear. For that reason, the range of strains in which the wire works has also an effect on the resulting attainable frequency for a given working amplitude. This is of great interest for SMA actuators since a similar working amplitude can result in very different attainable frequencies, depending on the range of temperatures within which the wire performs. Experimental results show that the SMA wire’s working frequency can be increased up to threefold by making it work within the appropriate temperature range. Afterwards, this improvement is reflected on the overall performance of the actuator in which the SMA wire is embedded.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Scholtes, Dominik, Yannik Goergen, Paul Motzki, Stefan Seelecke e Philipp Scheiner. "Soft Morphing Buttons Based on Actuator and Sensor Properties of Shape Memory Alloy Wires". In ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/smasis2019-5504.

Texto completo da fonte

Resumo:

Abstract As a smart material thermal shape memory alloys (SMAs) feature actuator behavior combined with self-sensing capabilities. With their high energy density and design flexibility they are predestined to be used in soft robotics and the emerging field of morphing surfaces. Such shape changing surfaces can be used for novel human-machine interaction (HMI) elements based on mode-/situation-dependent interfaces that may be applied to all kind of machines, appliances and smart home devices as well as automotive interiors. Since many of those contain textile surfaces, it is of special interest to place SMA-based actuator-sensor-elements beneath a textile cover or integrated them in the textile itself. In this study, the unique features of SMAs are used to design a system which represents an active “morphing” button. It can lower into the surface it is integrated in, pops up to be used and shows a proportional signal output depending on the pushing stroke. The system is characterized concerning haptics and sensor technology. The button consists of a TPU structure, to which two NiTi wires are attached. When activated, the SMAs contract and the structure curves upwards. The user can now push on the device to use it as a button. In the future, the use of SMA wires and for example TPU fibers enables direct integration in the production process of a possible smart and functional textile.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Relatórios de organizações sobre o assunto "Sma. smat"

Lee, Jusang, John E. Haddock e Jongmyung Jeon. Development of Volumetric Acceptance and Percent Within Limits (PWL) and Criteria for Stone Metrix Asphalt (SMA) Mixtures in Indiana. Purdue University, 2022. http://dx.doi.org/10.5703/1288284317580.

Texto completo da fonte

Resumo:

SMA is to be designed based on SMA volumetric properties in terms of air voids content (Va), voids in the mineral aggregate (VMA), and adequate stone-on-stone contact. For construction quality assurance (QA) purposes, INDOT currently accepts SMAs based on aggregate gradation and asphalt binder content. Thus, there is a discrepancy between SMA design criteria and construction acceptance. To better align design and construction, it is necessary to consider SMA volumetric properties in the use of QA. For HMA mixtures, INDOT has already transitioned from volumetric QA acceptance procedures to PWL. Today, SMA still uses adjustment points not based on robust statistics for QA acceptance. SMA QA samples and QA data sets were collected from projects constructed in 2019 and tested in the laboratory. The Hamburg Wheel Track Test (HWTT) was performed on the 2019 QA samples to evaluate SMA rutting performance. Additionally, the PWL for HMA was applied to the 2019 SMA QA data to see if the HMA PWL method would work for SMA. Possible SMA QA measurements were compared to past QA data and HMA QA measurements. In addition, Voids in the Coarse Aggregate (VCA) was evaluated as a possible SMA QA measurement. Finally, using the suitable QA measurements for SMA, a PWL parameter study was performed to find PWL that provides a Pay Factor (PF) equivalent to the current SMA Adjustment Point (AP) PF. The current SMA QA measurements (binder content, gradation, and density) are recommended for Indiana's SMA PWL. Based on the results of applying PWL to SMA QA data for the last four years, SMA PWL specification limits are recommended. Also, the SMA PF equations are suggested to get the SMA PWL to have PF equivalent to the current AP PF.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Lagoudas, D. C., e O. K. Rediniotis. Highly-Compact SMA Actuators A Feasibiltiy Study of Fuel-Powered and Thermoelectric SMA Actuators. Fort Belvoir, VA: Defense Technical Information Center, dezembro de 2003. http://dx.doi.org/10.21236/ada424753.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Matus, Sean, e Daniel Gambill. Automation of gridded HEC-HMS model development using Python : initial condition testing and calibration applications. Engineer Research and Development Center (U.S.), novembro de 2022. http://dx.doi.org/10.21079/11681/46126.

Texto completo da fonte

Resumo:

The US Army Corps of Engineers’s (USACE) Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) rainfall-runoff model is widely used within the research community to develop both event-based and continuous rainfall-runoff models. The soil moisture accounting (SMA) algorithm is commonly used for long-term simulations. Depending on the final model setup, 12 to 18 parameters are needed to characterize the modeled watershed’s canopy, surface, soil, and routing processes, all of which are potential calibration parameters. HEC-HMS includes optimization tools to facilitate model calibration, but only initial conditions (ICs) can be calibrated when using the gridded SMA algorithm. Calibrating a continuous SMA HEC-HMS model is an iterative process that can require hundreds of simulations, a time intensive process requiring automation. HEC-HMS is written in Java and is predominantly run through a graphical user interface (GUI). As such, conducting a long-term gridded SMA calibration is infeasible using the GUI. USACE Construction Engineering Research Laboratory (CERL) has written a workflow that utilizes the existing Jython application programming interface (API) to batch run HEC-HMS simulations with Python. The workflow allows for gridded SMA HEC-HMS model sensitivity and calibration analyses to be conducted in a timely manner.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Lagoudas, Dimitris C. Fatigue Life and Dynamic Response of SMA Actuators. Fort Belvoir, VA: Defense Technical Information Center, setembro de 2004. http://dx.doi.org/10.21236/ada433226.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Pfaeffle, H. J., Dimitris C. Lagoudas, Iradj Tadjbakhsh e Kevin C. Craig. Design of Flexible Rods with Embedded SMA Actuators. Fort Belvoir, VA: Defense Technical Information Center, janeiro de 1993. http://dx.doi.org/10.21236/ada260742.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Merchant, Bion J. CEA SMAD 2016 Digitizer Evaluation. Office of Scientific and Technical Information (OSTI), agosto de 2017. http://dx.doi.org/10.2172/1374793.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Rieu, Pierre, Samira Amraoui e Marco Restano. Standalone Multi-mission Altimetry Processor (SMAP). European Space Agency, junho de 2021. http://dx.doi.org/10.5270/esa-cnes.sentinel-3.smap.

Texto completo da fonte

Resumo:

SMAP is a standalone altimeter data processor written in Python 3 (3.7.3). It implements in particular the fully-focused SAR (FF-SAR) processing (both time-domain and frequency-domain algorithms). SMAP is currently able to process Sentinel-3 L1a Ground Segment products. This processor has been developed though studies and projects funded by ESA and CNES.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Patchett, B. M., e A. C. Bicknell. L51706 Higher-Strength SMAW Filler Metals. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), dezembro de 1993. http://dx.doi.org/10.55274/r0010418.

Texto completo da fonte

Resumo:

The welding of high strength steels in general, and for pipeline fabrication in particular, has shown that cracking due to hydrogen absorption during welding is more complex in these steels than in older, lower strength steels. In older steels, primary strengthening was accomplished with carbon, which caused hydrogen cracking in the base metal HAZ under reasonably predictable conditions involving microstructure, residual stress and hydrogen level. Pipeline steels were and are in the vanguard of change in strengthening philosophy. The change involves two areas of steel making, chemical composition and deformation processing. Pipeline steels now contain low carbon levels, in many cases less than 0.10%, and the resulting lack of strength is reclaimed by adding higher alloy levels to promote solution hardening (e.g. Mn), precipitation hardening (e.g. Cb, Cu) or transformation hardening (e.g. MO). In addition, alloy elements are added to improve toughness at high strength levels (e.g. Ni). At the same time, improvements have been made in reducing impurity and residual element levels, notably for S, P and O and N. Limitations on the effects of alloying additions on strength and toughness encouraged the use of deformation processing, primarily during rolling, to promote fine-grained microstructures to increase strength andtoughness simultaneously. Electrodes for the SMAW process have been developed for welding high-strength pipeline steels by using core wires made from high-strength microalloyed skelp extruded with cellulosic (Exx10) and low hydrogen (Exx16) flux coatings. The required alloy elements for high-strength deposits were therefore obtained from the core wire and not ferroalloy powders added to the flux, as is standard industrial practice. The idea behind this change was two fold: to avoid the possibility of introducing impurities from the varying sources of ferro alloy powders, including oxygen from the oxidized powder surfaces, and also to provide a closer match of the microalloy level to modern pipeline steel chemistries. The unknowns in this work were the effects of lower impurities/similar alloy content on the mechanical properties in the cast microstructure of a weld, compared to a pipe, and of the effect on electrode welding behaviour of a flux containing no ferro powders other than FeSi.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Wang, Bin, e Songye Zhu. EXPERIMENTAL INVESTIGATION OF SELF-CENTERING STEEL COLUMNS WITH SMA BOLTS. The Hong Kong Institute of Steel Construction, dezembro de 2018. http://dx.doi.org/10.18057/icass2018.p.103.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Lagoudas, Dimitris C. Thermomechanical Modeling and Experimentation for SMA Actuators under Cyclic Loading. Fort Belvoir, VA: Defense Technical Information Center, julho de 2002. http://dx.doi.org/10.21236/ada405599.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Oferecemos descontos em todos os planos premium para autores cujas obras estão incluídas em seleções literárias temáticas. Contate-nos para obter um código promocional único!