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Статті в журналах з теми "Linear FEM analyse"
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Ptaszny, Jacek, and Marcin Hatłas. "Evaluation of the FMBEM efficiency in the analysis of porous structures." Engineering Computations 35, no. 2 (April 16, 2018): 843–66. http://dx.doi.org/10.1108/ec-12-2016-0436.
Повний текст джерелаАнотація:
Purpose The purpose of this paper is to evaluate the efficiency of the fast multipole boundary element method (FMBEM) in the analysis of stress and effective properties of 3D linear elastic structures with cavities. In particular, a comparison between the FMBEM and the finite element method (FEM) is performed in terms of accuracy, model size and computation time. Design/methodology/approach The developed FMBEM uses eight-node Serendipity boundary elements with numerical integration based on the adaptive subdivision of elements. Multipole and local expansions and translations involve solid harmonics. The proposed model is used to analyse a solid body with two interacting spherical cavities, and to predict the homogenized response of a porous material under linear displacement boundary condition. The FEM results are generated in commercial codes Ansys and MSC Patran/Nastran, and the results are compared in terms of accuracy, model size and execution time. Analytical solutions available in the literature are also considered. Findings FMBEM and FEM approximate the geometry with similar accuracy and provide similar results. However, FMBEM requires a model size that is smaller by an order of magnitude in terms of the number of degrees of freedom. The problems under consideration can be solved by using FMBEM within the time comparable to the FEM with an iterative solver. Research limitations/implications The present results are limited to linear elasticity. Originality/value This work is a step towards a comprehensive efficiency evaluation of the FMBEM applied to selected problems of micromechanics, by comparison with the commercial FEM codes.
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Wang, Xiang Qiu, Zhi Guo Zhou, and Yu Hong Zhang. "Non-Linear FEM Analysis for the Layered Rock-Mass Tunnel Based on the Twin Shear Strength Criterion." Advanced Materials Research 168-170 (December 2010): 152–55. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.152.
Повний текст джерелаАнотація:
According to the geotechnical conditions, A FEM model has been established to analyse the mechanical characteristics of the highway tunnel in the layered rock mass. In this model the layered rock mass and the soften joint are simulated by the transversal isotropic material, the interfaces between layers are simulated by the element of rotational Goodman interface, but the interface between the lining structure and surrounding mass is proposed to simulate by an interface element with thickness, and the supporting of tunnel is simulated by the straight beam element. In the meantime, based on the twin shear strength criterion, the mechanical characteristics of rock, the stiff matrix of element for the layered rock mass, soften joint and interface have been discussed. The analytical model has been demonstrated by comparing the results of layered surrounding rock-mass FEM with the test data in situ.
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Akinpelu, Mutiu Adelodun, Bilyamin Adeoye Ibitoye, Samson Olalekan Odeyemi, and Kabir Opeyemi Olorede. "Numerical Verification of Strut and Tie Models and Failure Modes of Reinforced Self-Compacting Concrete Deep Beams." International Journal of Engineering Research in Africa 53 (March 2021): 76–100. http://dx.doi.org/10.4028/www.scientific.net/jera.53.76.
Повний текст джерелаАнотація:
This study utilized Finite Element Method (FEM) to analyse the structural behaviour and failure modes of Reinforced Self Compacting Concrete (RSCC) deep beams. Eighteen deep beam specimens subjected to four-point loadings were modelled and analyzed using Abaqus modelling tool. Damage plasticity model was used to characterised the nonlinear behaviour of concrete material while linear elastic, linear-plastic-hardening model represented the reinforcing steel material behaviour. The results of the finite model were compared with four different Strut and Tie Models (STMs) using one-way Analysis of Variance (ANOVA). Results of the numerical study revealed that the concrete strength and shear span to depth ratio mostly affect the load-deflection response of the beams. Also, the failure modes of the studied deep beams were influenced by shear span to depth ratio, concrete strength as well as web reinforcement distribution. The ANOVA results also showed that the FEM outperformed the existing STMs.
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Maleska, Tomasz, and Damian Beben. "Behaviour of corrugated steel plate bridge with high soil cover under seismic excitation." MATEC Web of Conferences 174 (2018): 04003. http://dx.doi.org/10.1051/matecconf/201817404003.
Повний текст джерелаАнотація:
The design codes and calculation methods related to the corrugated steel plate (CSP) bridges and culverts say only on the minimum soil height. This value is connected with the bridge span and shell height. In the case of static and dynamic loads (like passing the vehicles), such approach seems to be reasonable. However, it is important to know how the CSP bridges with high the soil covers behave under the seismic loads. This paper is presented the result of numerical study of CSP bridge with different high cover under seismic excitation. The analysed CSP railway bridge in the cross section has two closed pipe-arches. The span of shells is 4.40 m and the height of shells is 2.80 m. The load-carrying structure was constructed as two shells assembled from CSP sheets, designed with a depth of 0.05 m, pitch of 0.15 m, and plate thickness of 0.003 m. The real soil cover depth over the CSP structure (including ballast, blanket and backfill) equals 2.40 m. In this study two heights of soil cover were analysed (2.40 m and 5.00 m). Numerical analysis was conducted using the DIANA program based on finite element method (FEM). A linear model with El Centro records and Time History was used to analyse the problem.
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Plaitano, Francesco, Aurel Stratan, and Elide Nastri. "Simplified Modelling of Failure in High Strength Bolts under Combined Tension and Bending." Journal of Composites Science 6, no. 10 (October 11, 2022): 302. http://dx.doi.org/10.3390/jcs6100302.
Повний текст джерелаАнотація:
Bolted connections are widely adopted in steel structures and their behaviour affects to a large extent the global response of the system. High-strength bolts of type HV are commonly employed. Under pure tension, these bolt assemblies usually fail by thread stripping. However, it was observed experimentally that, under combined tension and bending, the failure mode changes to fracture of the shank. The former loading condition commonly occurs in the case of thick extended end plate connections and the latter in the case of flush end plates. In order to analyse the behaviour of the structure, the finite element method (FEM) is usually employed. While there is a wealth of information on FEM modelling of bolts for standard loading conditions (e.g., tension), the authors are unaware of a model able to replicate both tension-only and combined tension and bending conditions. In this paper, a simplified approach to be used in the framework of FEM is proposed to model the behaviour of high-strength HV bolts which can replicate the failure mechanism of bolts under tension only and combined tension and bending. The bolt assembly is modelled with continuum elements, supplemented by a non-linear spring connecting the nut to the bolt shank. The spring captures the stiffness, resistance, and ductility of the bolt-to-nut threaded connection, reproducing the experimentally observed failure mode in the case of pure tension conditions. A simplified damage model is applied to the continuum finite elements used to model the bolt, which replicates shank failure under combined tension and bending as a result of large local stresses and strains occurring under these conditions. The proposed model captures with good accuracy the actual behaviour of high-strength HV bolts under tension only as well as under combined tension and bending.
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Calderon Arenas, Jose Antonio. "Axisymmetric modelling of transient thermal response in solids for application to infrared photothermal radiometry technique." Revista Mexicana de Física 65, no. 1 (December 31, 2018): 54. http://dx.doi.org/10.31349/revmexfis.65.54.
Повний текст джерелаАнотація:
To induce temperature changes on the sample surface by the incidence of a monochromatic modulated light beam and detect the changes produced in the thermal radiation emission is the basic principle of the infrared photothermal radiometry technique. Until now, in order to analyze the thermal response mathematical models based in an one-dimensional model were used considering a sample with a finite thickness and an infinite incidence surface, as well as, the linear approximation of the Stefan-Boltzmann Law in the calculus of the heat losses due to thermal radiation. In this work, analytical and numerical models for the 2D heat diffusion in homogenous finite solid samples, are presented. These models were obtained by solving the heat diffusion equation, under cylindrical symmetry, considering mixed boundary conditions to include radiation and convection heat losses through the surfaces of the sample, and a monochromatic Gaussian excitation beam impinging on the front of the sample. The analytical models were obtained by solving the governing equations, considering the well-known linear approximation of the Stefan-Boltzmann law in the calculus of the heat losses due to thermal radiation. To analyse the effects of the non-linearity of the heat losses by thermal radiation on the thermal transient response, in the numerical model it was taken into account the full expression of the Stefan-Boltzmann law, and the transport equation was solved numerically by means of the Finite Element Method (FEM). The analytical solution for the oscillatory thermal response reveals the close dependence of the thermal response on the ratio of thickness to the radius of the sample, represented by the form factor sf. Both, the analytical and the numerical solutions were employed to simulate the thermal response of homogenous materials, and compared with experimental results reported elsewhere by part of our same research group. Finally, the difference between the thermal response predictions, from the analytical and numerical models, were analyzed.
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Devaud, Denis. "Petrov–Galerkin space-time hp-approximation of parabolic equations in H1/2." IMA Journal of Numerical Analysis 40, no. 4 (October 16, 2019): 2717–45. http://dx.doi.org/10.1093/imanum/drz036.
Повний текст джерелаАнотація:
Abstract We analyse a class of variational space-time discretizations for a broad class of initial boundary value problems for linear, parabolic evolution equations. The space-time variational formulation is based on fractional Sobolev spaces of order $1/2$ and the Riemann–Liouville derivative of order $1/2$ with respect to the temporal variable. It accommodates general, conforming space discretizations and naturally accommodates discretization of infinite horizon evolution problems. We prove an inf-sup condition for $hp$-time semidiscretizations with an explicit expression of stable test functions given in terms of Hilbert transforms of the corresponding trial functions; inf-sup constants are independent of temporal order and the time-step sequences, allowing quasi-optimal, high-order discretizations on graded time-step sequences, and also $hp$-time discretizations. For solutions exhibiting Gevrey regularity in time and taking values in certain weighted Bochner spaces, we establish novel exponential convergence estimates in terms of $N_t$, the number of (elliptic) spatial problems to be solved. The space-time variational setting allows general space discretizations and, in particular, for spatial $hp$-FEM discretizations. We report numerical tests of the method for model problems in one space dimension with typical singular solutions in the spatial and temporal variable. $hp$-discretizations in both spatial and temporal variables are used without any loss of stability, resulting in overall exponential convergence of the space-time discretization.
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HLADÍK, I., M. B. REED, and G. SWOBODA. "ROBUST PRECONDITIONERS FOR LINEAR ELASTICITY FEM ANALYSES." International Journal for Numerical Methods in Engineering 40, no. 11 (June 15, 1997): 2109–27. http://dx.doi.org/10.1002/(sici)1097-0207(19970615)40:11<2109::aid-nme163>3.0.co;2-1.
Повний текст джерела
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Różyło, P. "Experimental-numerical test of open section composite columns stability subjected to axial compression." Archives of Materials Science and Engineering 84, no. 2 (April 2, 2017): 58–64. http://dx.doi.org/10.5604/01.3001.0010.0979.
Повний текст джерелаАнотація:
Purpose: The aim of the work was to analyse the critical state of thin-walled composite profiles with top-hat cross section under axial compression. Design/methodology/approach: The purpose of the work was achieved by using known approximation methods in experimental and finite element methods for numerical simulations. The scope of work included an analysis of the behavior of thin-walled composite structures in critical state with respect to numerical studies verified experimentally. Findings: In the presented work were determined the values of critical loads related to the loss of stability of the structures by using well-known approximation methods and computer simulations (FEM analysis). Research limitations/implications: The research presented in the paper is about the potential possibility of determining the values of critical loads equivalent to loss of stability of thin-walled composite structures and the future possibility of analyzing limit states related to loss of load capacity. Practical implications: The practical approach in the actual application of the described specimen and methodology of study is related to the necessity of carrying out of strength analyzes, allowing for a precise assessment of the loads upon which the loss of stability (bifurcation) occurs. Originality/value: The originality of the research is closely associated with used the thinwalled composite profile with top-hat cross-section, which is commonly used in the fuselage of passenger airplane. The methodology of simultaneous confrontation of the obtained results of critical loads by using approximation methods and using the linear eigenvalue solution in numerical analysis demonstrates the originality of the research character. Presented results and the methodology are intended for researchers, who are concerned with the topic of loss of stability of thin-walled composite structures.
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Zhang, Yunpeng, Dorival M. Pedroso, and Ling Li. "FDM and FEM solutions to linear dynamics of porous media: stabilised, monolithic and fractional schemes." International Journal for Numerical Methods in Engineering 108, no. 6 (March 11, 2016): 614–45. http://dx.doi.org/10.1002/nme.5231.
Повний текст джерелаДисертації з теми "Linear FEM analyse"
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VIALE, NICOLA. "A new flat jack test for evaluating shear properties on unreinforced masonry." Doctoral thesis, Politecnico di Torino, 2020. http://hdl.handle.net/11583/2846617.
Повний текст джерела
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Lofink, Paul [Verfasser], Wolfgang H. [Akademischer Betreuer] Müller, Wolfgang H. [Gutachter] Müller, and Nikolai D. [Gutachter] Tutyshkin. "FEM-gestützte Analyse der linear-elastischen und hyperelastischen eigengravitierenden Erde unter dem Aspekt geometrischer und physikalischer Nichtlinearitäten / Paul Lofink ; Gutachter: Wolfgang H. Müller, Nikolai D. Tutyshkin ; Betreuer: Wolfgang H. Müller." Berlin : Technische Universität Berlin, 2018. http://d-nb.info/1156276659/34.
Повний текст джерела
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Jakel, Roland. "Lineare und nichtlineare Analyse hochdynamischer Einschlagvorgänge mit Creo Simulate und Abaqus/Explicit." Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-171812.
Повний текст джерелаАнотація:
Der Vortrag beschreibt wie sich mittels der unterschiedlichen Berechnungsverfahren zur Lösung dynamischer Strukturpobleme der Einschlag eines idealisierten Bruchstücks in eine Schutzwand berechnen lässt. Dies wird mittels zweier kommerzieller FEM-Programme beschrieben: a.) Creo Simulate nutzt zur Lösung die Methode der modalen Superposition, d.h., es können nur lineare dynamische Systeme mit rein modaler Dämpfung berechnet werden. Kontakt zwischen zwei Bauteilen lässt sich damit nicht erfassen. Die unbekannte Kraft-Zeit-Funktion des Einschlagvorganges muss also geeignet abgeschätzt und als äußere Last auf die Schutzwand aufgebracht werden. Je dynamischer der Einschlagvorgang, desto eher wird der Gültigkeitsbereich des zugrunde liegenden linearen Modells verlassen. b.) Abaqus/Explicit nutzt ein direktes Zeitintegrationsverfahren zur schrittweisen Lösung der zugrunde liegenden Differentialgleichung, die keine tangentiale Steifigkeitsmatrix benötigt. Damit können sowohl Materialnichtlinearitäten als auch Kontakt geeignet erfasst und damit die Kraft-Zeit-Funktion des Einschlages ermittelt werden. Auch bei extrem hochdynamischen Vorgängen liefert diese Methode ein gutes Ergebnis. Es müssen dafür jedoch weit mehr Werkstoffdaten bekannt sein, um das nichtlineare elasto-plastische Materialverhalten mit Schädigungseffekten korrekt zu beschreiben. Die Schwierigkeiten der Werkstoffdatenbestimmung werden in den Grundlagen erläutertThe presentation describes how to analyze the impact of an idealized fragment into a stell protective panel with different dynamic analysis methods. Two different commercial Finite Element codes are used for this: a.) Creo Simulate: This code uses the method of modal superposition for analyzing the dynamic response of linear dynamic systems. Therefore, only modal damping and no contact can be used. The unknown force-vs.-time curve of the impact event cannot be computed, but must be assumed and applied as external force to the steel protective panel. As more dynamic the impact, as sooner the range of validity of the underlying linear model is left. b.) Abaqus/Explicit: This code uses a direct integration method for an incremental (step by step) solution of the underlying differential equation, which does not need a tangential stiffness matrix. In this way, matieral nonlinearities as well as contact can be obtained as one result of the FEM analysis. Even for extremely high-dynamic impacts, good results can be obtained. But, the nonlinear elasto-plastic material behavior with damage initiation and damage evolution must be characterized with a lot of effort. The principal difficulties of the material characterization are described
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Teklemariam, Daniel Mekonnen, and Bennie Hamunzala. "Design of Thick Concrete Beams : Using Non-Linear FEM." Thesis, KTH, Bro- och stålbyggnad, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-189141.
Повний текст джерелаАнотація:
The experimental studies performed on the behaviour of very thick concrete beams subjected to static loads have revealed that the shear mechanisms play an important role in the overall response and failure behaviour. The aim of this thesis is to recommend suitable design methods for thick concrete beams subjected to off-centre static concentrated load according Eurocode 2 by using non-linear finite element analysis (NLFEA). To achieve this task, Abaqus/Explicit has been used by employing constitutive material models to capture the material non-linearity and stiffness degradation of concrete. Concrete damaged plasticity model and perfect plasticity model has been used for concrete and steel respectively. Three dilation angles (30º, 38º and 45º) and fracture energy from FIB 1990 (76 N/m) and FIB 2010 (142 N/m) has been used to investigate their influence on the finite element model. The dilation angle of 38º and FIB 2010 fracture energy was adopted as the suitable choice that reasonably matched with the experimental results. In verifying and calibrating the finite element model, the experimental results of the thick reinforced concrete beam conducted by the American Concrete Institute have been used. Three design approaches in the ultimate and serviceability limit state according to Eurocode 2 recommendations have been used namely; the beam method, strut and tie method and shell element method. Using the reinforcement detailing of the hand calculations of beam method and strut and tie method and linear finite element analysis of shell element method, non-linear finite element models have been pre-processed and analysed in Abaqus/Explicit. During the post-processing, the results have been interpreted and compared between the three design methods. The results under consideration are hand-calculated load at 0.3 mm crack width, FE-load at 0.3 mm crack width, amount of reinforcement and FE-failure load. The comparison of the results between the three design approaches (beam method, strut and tie method and shell element method) indicates that strut and tie method is better design approach, because it is relatively economic with regards to the quantity of reinforcement bars, has the higher load capacity and has a higher load at crack width of 0.3 mm crack width.De experimentella studier som utförts på tjocka betongbalkar som utsätts för statisk last har visat att skjuvning spelar en viktig roll i brottmekanismen. Syftet med detta examensarbete är att rekommendera lämpliga dimensioneringsmetoder för tjock betongbalkar utsatt for statisk koncentrerad last enligt Eurokod 2 med hjälp av ickelinjära finita element metod. Abaqus/Explicit användes genom att utnyttja konstitutiva materialmodeller för att fånga materialens icke-linjäritet och minskad styvhet. Tre dilatationsvinklar (30°, 38° och 45°) och två brottenergi från FIB 1990 (76 N/m) och FIB 2010 (142 N/m) tillämpas för att kontrollera deras inverkan på FE-modellerna. Dilatationsvinkel med 38° och FIB 2010 med högre brottenergi valdes i de icke-linjära finita elementanalyserna. Kontroll av FE-modellerna är baserad på ”American Concret Institutes” experimentella resultat på de tjocka betongbalkarna. Handberäkningar av tjocka betongbalkar har utförts i brott- och bruksgränstillstånd med tre dimensioneringsmetoder i Eurokod 2 nämligen balk metoden, fackverksmetoden och linjära-FE skalelementmetoden. Jämförelse har gjorts för de olika dimensioneringsmetoderna, genom att använda de armeringsdetaljer av handberäkningar i de verifierade och kalibrerade icke linjära FE-modellerna i Abaqus/Explicit. Resultaten i fråga är last för 0.3 mm handberäknad sprikvidd, FE-last för 0.3 mm sprikvidd, armeringsmängd och FE-brottlast. Jämförelse av resultaten mellan de tre dimensioneringsmetoder (balkmetod, fackverksmetod och skalelementmetod) visar att fackverksmetod är bättre design metod, eftersom det är relativt ekonomiskt med avseende på armeringsmängd, har högre lastkapacitet och last på 0.3 mm sprickvidd.
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Dettmann, Aaron. "Loosely coupled, modular framework for linear static aeroelastic analyses." Thesis, KTH, Lättkonstruktioner, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262047.
Повний текст джерелаАнотація:
A computational framework for linear static aeroelastic analyses is presented. The overall aeroelasticity model is applicable to conceptual aircraft design studies and other low-fidelity aero-structural analyses. A partitioned approach is used, i. e. separate solvers for aerodynamics and structure analyses are coupled in a suitable way, together forming a model for aeroelastic simulations. Aerodynamics are modelled using the vortexlattice method (VLM), a simple computational fluid dynamics (CFD) model based on potential flow. The structure is represented by a three-dimensional (3D) Euler-Bernoulli beam model in a finite element method (FEM) formulation. A particular focus was put on the modularity and loose coupling of aforementioned models. The core of the aeroelastic framework was abstracted, such that it does not depend on any specific details of the underlying aerodynamics and structure modules. The final aeroelasticity model constitutes independent software tools for the VLM and the beam FEM, as well as a framework enabling the aeroelastic coupling. These different tools have been developed as part of this thesis work. A wind tunnel experiment with a simple wing model is presented as a validation test case. An aero-structural analysis of a fully elastic unmanned aerial vehicle (UAV) (OptiMale) is described and results are compared with an existing higherfidelity study.Rapporten beskriver en beräkningsmodell för linjära, statisk aeroelastiska analyser. Modellen kan användas för konceptuella designstudier av flygplan. En partitionerad metod används, d v s separata lösare för aerodynamik- och strukturanalyser kopplas på ett lämpligt sätt, och bildar tillsammans en modell för aeroelastiska simulationer. Aerodynamik modelleras med hjälp av en så kallad vortex-lattice method (VLM), en enkel modell för beräkningsströmningsdynamik (CFD) som är baserad på friktionsfri strömning. Strukturen representeras av en tredimensionell (3D) Euler-Bernoulli-balkmodell implementerad med hjälp av en finita elementmetod (FEM). Ovannämnda modeller har utvecklats med fokus på modularitet och lös koppling. Kärnan i den aeroelastiska modellen har abstraherats så att den inte beror på specifika detaljer i de underliggande aerodynamik- och strukturmodulerna. Aeroelasticitetsmodellen i sin helhet består av separata mjukvaruprogram för VLM och balk-FEM, såväl som ett ramverk som möjliggör den aeroelastiska kopplingen. Dessa olika program har utvecklats som en del av examensarbetet. Ett vindtunnelförsök med en enkel vingmodell presenteras som ett valideringstest. Dessutom beskrivs en analys av ett elastiskt obemannad flygplan (OptiMale) och resultaten jämförs med en befintlig studie som har genomförts med modeller av högre trovärdighet.
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Denimal, Enora. "Prédiction des instabilités de frottement par méta-modélisation et approches fréquentielles : Application au crissement de frein automobile." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEC039/document.
Повний текст джерелаАнотація:
Le crissement de frein est une nuisance sonore qui représente des coûts importants pour l'industrie automobile. Il tire son origine dans des phénomènes complexes à l'interface frottante entre les plaquettes de frein et le disque. L'analyse de stabilité reste aujourd'hui la méthode privilégiée dans l'industrie pour prédire la stabilité d'un système de frein malgré ses aspects sur- et sous-prédictifs.Afin de construire un système de frein robuste, il est nécessaire de trouver la technologie qui permette de limiter les instabilités malgré certains paramètres incertains présents dans le système. Ainsi, l'un des objectifs de la thèse est de développer une méthode permettant de traiter et de propager l'incertitude et la variabilité de certains paramètres dans le modèle éléments finis de frein avec des coûts numériques abordables.Dans un premier temps, l'influence d'un premier groupe de paramètres correspondant à des contacts internes au système a été étudiée afin de mieux comprendre les phénomènes physiques mis en jeu et leurs impacts sur le phénomène de crissement. Une approche basée sur l'utilisation d'un algorithme génétique a été également mise en place afin d'identifier le jeu de paramètres le plus défavorable en terme de propension au crissement sur le système.Dans un second temps, différentes méthodes de méta-modélisation ont été proposées afin de prédire la stabilité du système de frein en fonction de différents paramètres qui peuvent être des paramètres de conception ou des paramètres incertains liés à l'environnement du système.Dans un troisième temps, une méthode d'analyse non-linéaire complémentaire de l'analyse de stabilité a été proposée et développée. Elle se base sur le suivi de la stabilité d'une solution vibratoire approchée et permet d'identifier les modes instables présents dans la réponse dynamique du système. Cette méthode a été appliquée sur un modèle simple avant d'illustrer sa faisabilité sur le modèle éléments finis de frein completBrake squeal is a noise nuisance that represents significant costs for the automotive industry. It originates from complex phenomena at the frictional interface between the brake pads and the disc. The stability analysis remains the preferred method in the industry today to predict the stability of a brake system despite its over- and under-predictive aspects.In order to build a robust brake system, it is necessary to find the technology that limits instabilities despite some uncertain parameters present in the system. Thus, one of the main objectives of the PhD thesis is to develop a method to treat and propagate the uncertainty and variability of some parameters in the finite element brake model with reasonable numerical costs.First, the influence of a first group of parameters corresponding to contacts within the system was studied in order to better understand the physical phenomena involved and their impacts on the squealing phenomenon. An approach based on the use of a genetic algorithm has also been implemented to identify the most unfavourable set of parameters in terms of squeal propensity on the brake system.In a second step, different meta-modelling methods were proposed to predict the stability of the brake system with respect to different parameters that may be design parameters or uncertain parameters related to the environment of the brake system.In a third step, a non-linear analysis method complementary to the stability analysis was proposed and developed. It is based on the tracking of the stability of an approximate vibrational solution and allows the identification of unstable modes present in the dynamic response of the system. This method was applied to a simple academic model before demonstrating its feasibility on the complete industrial brake finite element model under study
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Makhlouf, Heba. "Essais virtuels pour l'industrie du meuble." Thesis, Paris Est, 2015. http://www.theses.fr/2015PESC1164.
Повний текст джерелаАнотація:
Le travail s’inscrit dans le cadre d’une collaboration entre le Pôle Ameublement FCBA et le Laboratoire MSME de l’UPEM. L’objectif était de mettre au point un outil de simulation permettant à FCBA de mener une étude de validation (tenue aux tests normalisés) avant la fabrication du meuble. Ce travail était supporté par les fonds collectifs de la profession ameublement. Il a donné lieu à des développements dans le domaine de l’identification du comportement anisotrope du bois par analyse d’images couplée à la méthode des éléments finis, d’une approche multi-échelle pour identifier le comportement des liens entre éléments de meuble et d’un programme éléments finis utilisant l’approche « poutres » pour réaliser une étude statistique du comportement du meuble prenant en compte la dispersion du comportement du bois. Chaque étape a été validée expérimentalement. La simulation par éléments finis s’est focalisée sur une application « lits superposées en bois massif » pour laquelle un code à base de poutres a été développé dans l’environnement Matlab afin de pouvoir y implanter :• une théorie élastique anisotrope via des poutres de Timoshenko pour prendre en compte l’effet des déformations dues aux faibles rigidités transversales du bois en regard de la rigidité longitudinale ;• des éléments de connexion ponctuels représentant la contribution des composants de quincaillerie (vis, écrou noyé, tourillon…) et les effets locaux 3D aux liaisons entre poutres ;• la possibilité de prendre en compte les incertitudes sur les paramètres matériau d’une poutre à l’autre en fonction de l’orientation des planches, de la densité du bois etc… via une simulation de Monte-CarloThe work joins within the framework of a collaboration between the Pole Furnishing FCBA and the Laboratory MSME of the UPEM. The objective was to finalize(to work out) a tool of simulation allowing FCBA to lead a study of validation (held the normalized(standardized) tests) before the manufacturing of the piece of furniture
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Pablos, Rabano Alejandro. "Modeling of a PMSynRel stator with concentrated windings using FEM and non-linear reluctance networks." Thesis, KTH, Elektrisk energiomvandling, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-124543.
Повний текст джерелаАнотація:
Permanent magnets synchronous reluctance (PMSynRel) motors are attractive due to their high torque density and because a lower quantity of permanent magnets is necessary in comparison with other permanent magnet machines. This thesis deals with the analysis of PMSynRel machines using a finite element method (FEM) and reluctance networks. First, a PMSynRel machine model is built in order to carry out simulations using a finite element method package. The effect of different design parameters such as the combination of the number of poles and slots, the number of flux barriers or the number of magnets can be studied since the implementation provides the possibility to change those variables. Next, a reluctance networks model, aimed to enable lower computation times than corresponding finite element models, is implemented for analysing the flux density distributions along the air gap of the machine disregarding the magnetic influence of the rotor. Finally, the results are compared with FEM simulations. It is concluded that the agreement reached is satisfactory in most of the cases analysed.
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Alagbada, Adefemi Samuel. "Thermo-Mechanical Fatigue Assessment of Marine Boiler : Using linear Finite Element Analyses." Thesis, Linnéuniversitetet, Institutionen för maskinteknik (MT), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-95439.
Повний текст джерелаАнотація:
This thesis is on fatigue crack growth assessments of a thermomechanical loaded Marine Boiler- Sunrod CPDB12. The installation position of the marine boiler in the ship in relation to its fatigue life under mode 1 loading is investigated. Thermomechanical loading embodies pressures, temperatures, RAO, subjected to the rigid body dynamic of ship in the marine environment. Linear elastic fracture mechanics (LEFM) method was used is predicting the growth rates of the welding flaws at the joint based on stress range of the Paris law relationship. FEA Numerical simulation delivered better crack growth rate assessments and life predictions of the smallest detectable flaws in the boiler. The identified smallest detestable flaws at the welding joint diminishing the designed safe life of the boiler significantly. Also, installation position within the ship do affect the fatigue life of the boiler.
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Selli, Nicola. "Static and seismic analysis of a historic masonry building in San Pio delle Camere." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2022.
Знайти повний текст джерелаАнотація:
In February 2021, in San Pio delle Camere, on the Navelli plateau south-east of L'Aquila, a masonry building collapsed suddenly, after repair work had just begun on the damage caused by the 2009 earthquake. The current study, after a detailed examination of all the design documentation and the comparison of the post-earthquake damage with the results of the analysis on the model, finding an excellent correspondence, went to research the possible causes of the structural collapse, which occurred in static conditions. The masonry texture was then analysed, consisting of unworked natural stones of medium-small size bound by poor quality mortar, parameterising the mechanical characteristics with in situ tests, the Masonry Quality Index and the values proposed in NTC 2018. Then, the analysis of the global model lead to the verification of the complexity of the aggregate induced greater pressures, and consequent deformations, precisely in the walls from which the collapse originated. With these assumptions, and from the evidence of the presence of a modest void in an internal facing, the study of the local mechanism was deepened, arriving at the presumption of the possible minimum dimensions of such a cavity and how this, even if minimal, could have been the cause if concomitant with the degradation of the bonding mortar induced by the absence of maintenance and the loss of even minimal resistance capacities.
Книги з теми "Linear FEM analyse"
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Gagliardi, Isabella, ed. Le vestigia dei gesuati. Florence: Firenze University Press, 2020. http://dx.doi.org/10.36253/978-88-5518-228-7.
Повний текст джерелаАнотація:
The book analyses the history of the Jesuat congregation, highlighting the elements of connection and comparison with the social contexts, then describing the origin and the most ancient events of the female branch of the congregation, and the memory of the meeting between the "founder" of the Jesuats and the "foundress" of the Gesuate. The iconographic memory of the initiator of the congregation, Giovani Colombini, the collection of the lauds of the Jesuat Bianco da Siena, and the fortune of the 15th-century Life of Giovanni Colombini, written by Feo Belcari, are also investigated. Then the research reconstructs the constellation of groups, religious experiments and bearers of ideas and devotions that were linked to the Jesuats and, in particular, to the convents of Milan, Siena, Lucca, Venice and Rome and the sanctuaries managed by the congregation. The congregational sociability is analysed along its lines: the practice of work as pharmacists and the cultivation of spiritual friendships with prominent people such as the Countess of Guastalla, Lodovica Torelli. Finally, the erudite use of Colombini's Epistolario as a language text is studied. The volume closes with a documentary appendix on the Jesuat convent of Chiusi.
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Walsh, Bruce, and Michael Lynch. Analysis of Short-term Selection Experiments: 1. Least-squares Approaches. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198830870.003.0018.
Повний текст джерелаАнотація:
This chapter examines short-term (a few generations) selection response in the mean of a trait. Traditionally, such experiments are analyzed using least-squares (LS) approaches. While ordinary LS (OLS) is often used, genetic drift causes the residual to be both correlated and heteroscedastic, resulting in the sampling variances given by OLS being too small. This chapter details the appropriate general LS (GLS) approaches to properly account for this residual error structure. It also reviews some of the common features observed in short-term selection experiments and examines experimental designs, such as the use of a control population versus a divergence-selection approach. It concludes by discussing another linear model used mainly by plant breeders, generation-means analysis (GMA), wherein remnant seed for several generations of response are crossed and then grown in a common garden. Such an analysis can provide insight into the genetic nature of any response.
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North, Susan. Sweet and Clean? Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198856139.001.0001.
Повний текст джерелаАнотація:
Sweet and Clean? Bodies and Clothes in Early Modern England challenges the widely held beliefs on bathing and cleanliness in the past. For over 30 years, the work of the French historian, George Vigarello, has been hugely influential on early modern European social history, describing an aversion to water and bathing, and the use of linen underwear as the sole cleaning agent for the body. However, these concepts do not apply to early modern England. Sweet and Clean? analyses etiquette and medical literature revealing repeated recommendations to wash or bathe in order to clean the skin. Clean linen was essential for propriety but advice from medical experts was contradictory. Many doctors were convinced that it prevented the spread of contagious diseases, but others recommended flannel for undergarments, and a few thought changing a fever patient’s linens was dangerous. The methodology of material culture helps determine if and how this advice was practised. Evidence from inventories, household accounts and manuals, and surviving linen garments tracks underwear through its life-cycle of production, making, wearing, laundering, and final recycling. Although the material culture of washing bodies is much sparser, other sources, such as the Old Bailey records, paint a more accurate picture of cleanliness in early modern England than has been previously described. The contrasting analyses of linen and bodies reveal what histories material culture best serves. Finally, what of the diseases—plague, smallpox, and typhus—that cleanliness of body and clothes were thought to prevent? Did following early modern medical advice protect people from these illnesses?
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Pritchett, Lant, Kunal Sen, and Eric Werker, eds. Deals and Development. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198801641.001.0001.
Повний текст джерелаАнотація:
When are developing countries able to initiate periods of rapid growth and why have so few of these countries been able to sustain growth over decades? Deals and Development: The Political Dynamics of Growth Episodes seeks to answer these questions and many more through a novel conceptual framework built from a political economy of business–government relations. Economic growth for most developing countries is not a linear process. Growth instead proceeds in booms and busts, yet most frameworks for thinking about economic growth are built on the faulty assumption that a country’s economic performance is largely stable. Deals and Development explains how growth episodes emerge and when growth, once ignited, is maintained for a sustained period. It applies its new framework to examining the growth of countries across a range of institutional and political contexts in Africa and Asia, using the examples of Bangladesh, Cambodia, India, Malaysia, Thailand, Ghana, Liberia, Malawi, Rwanda, and Uganda. Through these country analyses it demonstrates the explanatory power of its framework and the importance of feedback cycles in which economic trends interact with political behaviour to either sustain or terminate a growth episode. Offering a lens through which to analyse complex scenarios and unwieldy amounts of information, this book provides actionable levers of intervention to bring around reform and improve a country’s chance at achieving transformative economic growth.
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Rathey, Markus. Bach in the World. Oxford University PressNew York, 2022. http://dx.doi.org/10.1093/oso/9780197578841.001.0001.
Повний текст джерелаАнотація:
Abstract Johann Sebastian Bach’s works are often classified along the lines of “sacred” versus “secular.” While this distinction is fraught with problems, it seems to provide a useful way to distinguish between Bach’s vocal works for the liturgy and those that were written to honor courts and members of the nobility. But even within this second group, the lines cannot be drawn that clearly. The political and social systems of Bach’s time relied on religion as an ideological foundation, and public displays of political power almost always included religious rituals and thus required some form of sacred music. Social constructs, such as class and gender, were also embedded in religious frameworks. The book analyzes public manifestations of the social order during Bach’s time in large-scale celebrations, processions, public performances, and visual displays. By analyzing selected cantatas, the book explores how Bach’s music functioned as an agent of affective communication within rituals, such as the installation of the town council, and as a place where sociopolitical norms were perpetuated and—in a few cases—even challenged.
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Darrigol, Olivier. Models, structure, and generality in Clerk Maxwell’s theory of electromagnetism. Edited by Karine Chemla, Renaud Chorlay, and David Rabouin. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780198777267.013.12.
Повний текст джерелаАнотація:
This article examines the gradual development of James Clerk Maxwell’s electromagnetic theory, arguing that he aimed at general structures through his models, illustrations, formal analogies, and scientific metaphors. It also considers a few texts in which Maxwell expounds his conception of physical theories and their relation to mathematics. Following a discussion of Maxwell’s extension of an analogy invented by William Thomson in 1842, the article analyzes Maxwell’s geometrical expression of Michael Faraday’s notion of lines of force. It then revisits Maxwell’s honeycomb model that he used to obtain his system of equations and the concomitant unification of electricity, magnetism, and optics. It also explores Maxwell’s view about the Lagrangian form of the fundamental equations of a physical theory. It shows that Maxwell was guided by general structural requirements that were inspired by partial and temporary models; these requirements were systematically detailed in Maxwell’s 1873 Treatise on electricity and magnetism.
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Wilson, Keeley. A Shooting Star. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198777199.003.0001.
Повний текст джерелаАнотація:
No large industrial company has ever grown as fast as Nokia did in the 1990s and few have fallen quite as rapidly: Nokia’s mobile phone business went from posting record results in 2007 to almost dragging the whole company into bankruptcy in 2012. The opening chapter sets the scene with a brief history of Nokia’s journey. Three different lines of theoretical reasoning which could explain Nokia’s decline are discussed: unavoidable Schumpeterian creative destruction, organizational evolution gone astray, and a failure of managerial volition. The CORE dimensions used in the analysis of each chapter are introduced: Cognition (what leaders saw, how they interpreted it, conclusions they drew, and decisions made); Organization (operational actions, managers’ responsibilities, and relationships in the firm); Relationships (interpersonal element of how leaders complement each other, how well they work together, and the ambitions they harbor); and Emotions (critical to the quality of strategic sense-making and collective commitment).
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Scarlet, Janina, Ariel J. Lang, and Robyn D. Walser. Acceptance and Commitment Therapy for Posttraumatic Stress Disorder. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780190205959.003.0003.
Повний текст джерелаАнотація:
This chapter examines evidence for the effectiveness of complementary and alternative medicine (CAM) for posttraumatic stress disorder (PTSD). There is high demand for CAM among both military and civilian consumers and thus CAM for PTSD warrants thorough analysis. The CAM interventions reviewed herein include mindfulness and other meditative practices, acupuncture, yoga, relaxation, breathing training, and physical exercise. Although there are few rigorous studies of CAM for PTSD, available evidence suggests that these approaches are moderately effective. They would generally not be considered a first line intervention for PTSD at this point, but rather would be recommended as an adjunct to established approaches. The limited number of studies available, however, precludes drawing firm conclusions. Thus, future work should focus on better understanding the optimal uses of CAM for PTSD.
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Drach, Alexis, and Youssef Cassis, eds. Financial Deregulation. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198856955.001.0001.
Повний текст джерелаАнотація:
A wave of liberalization swept the end of the twentieth century. From the 1970s and 1980s onwards, most developed countries have passed various measures to liberalize and ‘modernize’ the financial markets. Each country had its agenda, but most of them have experienced, to a different extent, a change in regulatory regime. This change, often labelled deregulation and associated with the advent of neoliberalism, was sharply contrasting with the previous era, the Bretton Woods system, which has sometimes been portrayed as an era of ‘financial repression’. On the other hand, a quick glance at financial regulation today, at the amount of paper it produces, at its complexity, at the number of people involved, and at the resources invested in it, is enough to say that, somehow, there is more regulation today than ever before. In the new system, financial regulation has taken unprecedented importance. As more archival material is becoming available, a better understanding of the fundamental changes in the regulatory environment towards the end of the twentieth century is now possible. What kind of change exactly was deregulation? Did competition between financial regulators lead to a ‘race to the bottom’ in regulation? Is deregulation responsible for the recurring financial crises which seem to have characterized the international financial system since the 1980s? The movement towards a more liberal regulatory regime was neither linear nor simple. This book—a collection of chapters studying deregulation in various countries and contexts—examines the national and international pathways of deregulation by providing an in-depth analysis of a short but crucial period in a few major countries.
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Nitzan, Abraham. Chemical Dynamics in Condensed Phases. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780198529798.001.0001.
Повний текст джерелаАнотація:
This text provides a uniform and consistent approach to diversified problems encountered in the study of dynamical processes in condensed phase molecular systems. Given the broad interdisciplinary aspect of this subject, the book focuses on three themes: coverage of needed background material, in-depth introduction of methodologies, and analysis of several key applications. The uniform approach and common language used in all discussions help to develop general understanding and insight on condensed phases chemical dynamics. The applications discussed are among the most fundamental processes that underlie physical, chemical and biological phenomena in complex systems. The first part of the book starts with a general review of basic mathematical and physical methods (Chapter 1) and a few introductory chapters on quantum dynamics (Chapter 2), interaction of radiation and matter (Chapter 3) and basic properties of solids (chapter 4) and liquids (Chapter 5). In the second part the text embarks on a broad coverage of the main methodological approaches. The central role of classical and quantum time correlation functions is emphasized in Chapter 6. The presentation of dynamical phenomena in complex systems as stochastic processes is discussed in Chapters 7 and 8. The basic theory of quantum relaxation phenomena is developed in Chapter 9, and carried on in Chapter 10 which introduces the density operator, its quantum evolution in Liouville space, and the concept of reduced equation of motions. The methodological part concludes with a discussion of linear response theory in Chapter 11, and of the spin-boson model in chapter 12. The third part of the book applies the methodologies introduced earlier to several fundamental processes that underlie much of the dynamical behaviour of condensed phase molecular systems. Vibrational relaxation and vibrational energy transfer (Chapter 13), Barrier crossing and diffusion controlled reactions (Chapter 14), solvation dynamics (Chapter 15), electron transfer in bulk solvents (Chapter 16) and at electrodes/electrolyte and metal/molecule/metal junctions (Chapter 17), and several processes pertaining to molecular spectroscopy in condensed phases (Chapter 18) are the main subjects discussed in this part.
Частини книг з теми "Linear FEM analyse"
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Blaauwendraad, Johan. "Reinforcement Design Using Linear Analysis." In Plates and FEM, 291–318. Dordrecht: Springer Netherlands, 2009. http://dx.doi.org/10.1007/978-90-481-3596-7_16.
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Oñate, Eugenio. "Programming the Fem For Beam, Plate and Shell Analysis in Mat-fem." In Structural Analysis with the Finite Element Method Linear Statics, 729–90. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-1-4020-8743-1_12.
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Tiemin, Zhang, Cao Fei, Li Shenghua, Liang Li, and Wen Sheng. "FEM Analysis and Parameter Optimization of a Linear Piezoelectric Motor Macro Driven." In Intelligent Robotics and Applications, 171–78. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-13966-1_17.
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Xu, Zhen, Junfeng Sun, Taohong Liao, Xiangping Hu, and Xuedong Zhang. "Performance Analysis of Ball Mill Liner Based on DEM-FEM Coupling." In Lecture Notes in Electrical Engineering, 3–10. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-2341-0_1.
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Krishnasamy, M., J. R. Shinde, H. P. Mohammad, G. Amarnath, and Trupti Ranjan Lenka. "Design and Analysis of FEM Novel X-Shaped Broadband Linear Piezoelectric Energy Harvester." In Lecture Notes in Electrical Engineering, 407–16. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-3767-4_39.
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Seidl, Helmut, Vesal Vojdani, and Varmo Vene. "A Smooth Combination of Linear and Herbrand Equalities for Polynomial Time Must-Alias Analysis." In FM 2009: Formal Methods, 644–59. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-05089-3_41.
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Takács, P. F., K. V. Høiseth, S. I. Sørensen, T. Kanstad, J. A. Øverli, and E. Thorenfeldt. "Non-linear analysis of prestressed concrete beams with a total strain based model: FEM model and full-scale testing." In Finite Elements in Civil Engineering Applications, 201–8. London: CRC Press, 2021. http://dx.doi.org/10.1201/9781003211365-28.
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Si, Jikai, Shaohua Wang, Xiaozhuo Xu, Haicao Feng, and Xudong Wang. "Analysis of Characteristics of Permanent Magnet Linear Motor Fed by Sinusoidal and Non-sinusoidal Power Supply." In Electrical, Information Engineering and Mechatronics 2011, 2073–79. London: Springer London, 2012. http://dx.doi.org/10.1007/978-1-4471-2467-2_245.
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Calabretta, Michele, Alessandro Sitta, Salvatore Massimo Oliveri, and Gaetano Sequenzia. "Analysis of Warpage Induced by Thick Copper Metal on Semiconductor Device." In Lecture Notes in Mechanical Engineering, 55–60. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-70566-4_10.
Повний текст джерелаАнотація:
AbstractElectrochemical deposited (ECD) thick film copper on silicon substrate is one of the most challenging technological brick for semiconductor industry representing a relevant improvement from the state of art because of its excellent electrical and thermal conductivity compared with traditional compound such as aluminum. The main technological factor that makes challenging the industrial implementation of thick copper layer is the severe wafer warpage induced by Cu annealing process, which negatively impacts the wafer manufacturability. The aim of presented work is the understanding of warpage variation during annealing process of ECD thick (~20 µm) copper layer. Warpage has been experimental characterized at different temperature by means of Phase-Shift Moiré principle, according to different annealing profiles. A linear Finite Element Model (FEM) has been developed to predict the geometrically stress-curvature relation, comparing results with analytical models.
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Rüd, Sophie, Hilmar Müller, Helmut Fleischer, and Christoph Stephan. "Development of a Verification Procedure of Partial Loading on Existing Solid Hydraulic Structures - Probabilistic Assessment for 3D Material Variations." In Lecture Notes in Civil Engineering, 372–83. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6138-0_33.
Повний текст джерелаАнотація:
AbstractOne of the challenges in assessing the load-bearing capacity of existing solid hydraulic structures is the formal verification of concentrated loads for plain concrete. Due to the age bandwidth of such structures in Germany, this applies to hundreds of cases and especially to older structures of rammed concrete. Typical examples of components subjected to partial loads are found at weir pillars: e.g. support niches of inspection closures. Although they cannot be formally verified using the current regulations, the BAW Code of Practice “Evaluation of the load bearing capacity of existing solid hydraulic structures” (TbW) allows more detailed investigation methods to be applied, e.g. the use of non-linear probabilistic calculations. The principle research motivations are a higher loading capacity by numerical simulations with a more realistic material model compared to the usual linear calculations and a higher loading capacity by reproducing a “natural” bandwidth of material characteristics in these simulations. The aim of the current research project is the development and standardisation of the numerical simulations for such a verification procedure and its underlying safety concept by a classification of structural markers. As a result, the necessity of complex reinforcements for such structures could be assessed. The paper introduces the research concept and addresses the investigation steps regarding measured and generic 3D material distributions and FEM representation specifics as the material model. Furthermore, the preparation of the stochastic analysis is introduced by a demonstration model: The resulting hundreds to thousands of simulations of individual cases enable the stochastic analysis of metamodels to deduce general probabilistic results. Prospectively, the demonstration model will be transferred to further component measures and compressive strength classes.
Тези доповідей конференцій з теми "Linear FEM analyse"
1
Pişkin, Altuğ, and Ahmet Topal. "Coupled CFD and Heat Transfer Analysis for a Small Scale Gas Turbine Combustor." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57846.
Повний текст джерелаАнотація:
Gas turbine combustor design process has significant number of design parameters because of contained complex phenomena. One of the most complicated of these is the heat transfer process of combustor liners. Heat transfer studies are performed in preliminary design phase by the help of one-dimensional tools and combustor geometry is shaped to satisfy design requirements. However; in the detail design phase, a fine tuning can be required to optimize it by using 3D CFD analysis. Conjugate heat transfer is a powerful tool to simulate interaction between reacting flow and combustor liners in detail design phase. But it is difficult to use computationally expensive conjugate heat transfer analysis in design iterations for calculating liner metal temperatures because of the high computation times. Its application will be mainly limited to optimized final geometries and steady simulations. On the other hand, when the 3D liner temperatures are required for structural evaluation during the preliminary design phase; coupled analysis of Finite Element Analysis (FEA)/ Computational Fluid Dynamics (CFD) can provide quick alternative solution. Coupled analysis requires lower mesh size and less calculation time comparing to the conjugate analysis. During a coupled analysis, an iterative boundary information exchange is conducted until the desired convergence criterion is reached. In this study, a series of numerical analyses are evaluated and the relevant rig test thermal paint results are presented. Numerical analyses consist of coupled analyses with various boundary condition cases. Some of these cases have the complete set of boundary conditions and they assumed as comparable to the test condition. In the coupling process, FEM use the near wall gas temperature data that comes from CFD solution and CFD uses wall temperature data that comes from the FEM solution. Heat transfer coefficients are not coupled and they are obtained from empirical heat transfer correlations. An atmospheric combustor test rig was used to apply thermal paint and thermocouple measurements were taken from the combustor outer liner. Numerical and experimental values of the liner temperatures are also compared and analyzed.
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Fatima, Arooj, Stefan Turek, Abderrahim Ouazzi, and Muhammad Aaqib Afaq. "An adaptive discrete Newton method for regularization-free Bingham model." In VI ECCOMAS Young Investigators Conference. València: Editorial Universitat Politècnica de València, 2021. http://dx.doi.org/10.4995/yic2021.2021.12389.
Повний текст джерелаАнотація:
Developing a numerical and algorithmic tool which correctly identifies unyielded region in the yield stress fluid flow is a challenging task. Two approaches are commonly used to handle the singular behaviour at the yield surface, i.e. Augmented Lagrangian approach and the regularization approach, respectively. Generally in the regularization approach, solvers do not perform efficiently when the regularization parameter gets very small. In this work, we use a formulation introducing a new auxiliary stress [1]. The three field formulation of yield stress fluid corresponds to a regularization-free Bingham formulation. The resulting set of equations arising from the three field formulation is solved efficiently and accurately by a monolithic finite element method. The velocity and pressure are discretized by higher order stable FEM pair $Q_2/P^{\text{disc}}_1$ and the auxiliary stress is discretized by $Q_2$ element.Furthermore, this problem is highly nonlinear and presents a big challenge to any nonlinear solver. We developed a new adaptive discrete Newton's method, which evaluates the Jacobian with the directional divided difference approach [2]. The step length in this process is an important key: We relate this length to the rate of the actual nonlinear reduction for achieving a robust adaptive Newton's method. The resulting linear sub problems are solved using the geometrical multigrid solver. We analyse the solvability of the problem along with the adaptive Newton method for Bingham fluids by doing numerical studies for two different prototypical configurations, i.e. "Viscoplastic fluid flow in a channel" and "Lid Driven Cavity", respectively [2].REFERENCES[1] Aposporidis, A., Haber, E., Olshanskii, M. A. and Veneziani, A. A mixed formulation of the Bingham fluid flow problem: Analysis and numerical solution. Comput. Methods Appl. Mech. Engrg, Vol. 200, pp. 2434–2446, (2011).[2] Fatima, A., Turek, S., Ouazzi, A. and Afaq, M. A. An adaptive discrete Newton method for regularization-free Bingham model. Ergebnisberichte des Instituts fuer Angewandte Mathematik Nummer 635, Fakultaet fuer Mathematik, TU Dortmund University, 635, 2021.
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Satoh, Naoshi, Tetsuya Sakai, and Mamoru Aida. "Non-Linear FEM Analysis of the Trunnion Suspension System." In International Truck & Bus Meeting & Exposition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1991. http://dx.doi.org/10.4271/912714.
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Toenshoff, Hans K., and Axel Stegmann. "FEM analysis of a bimodal linear piezo-friction motor." In Smart Structures and Materials '97, edited by Mark E. Regelbrugge. SPIE, 1997. http://dx.doi.org/10.1117/12.275658.
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Guo Liang, Lu Qinfen, and Ye Yunyue. "FEM analysis of the linear generator EMF in Maglev." In Proceedings of the Eighth International Conference on Electrical Machines and Systems. IEEE, 2005. http://dx.doi.org/10.1109/icems.2005.202937.
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Jindra, Daniel, Petr Hradil, Jiří Kala та Vlastislav Salajka. "Non linear FEM analysis οf composite concrete slab exposed τo extreme thermal load". У INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS ICNAAM 2019. AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0026880.
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Lund, Espen, Mladen Jecmenica, Hamid Reza Karimi, Kjell G. Robbersmyr, and Ole Melteig. "Energy analysis of a non-linear dynamic impact using FEM." In 2014 11th World Congress on Intelligent Control and Automation (WCICA). IEEE, 2014. http://dx.doi.org/10.1109/wcica.2014.7053760.
Повний текст джерела
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Sulejmani, Xevat, and Goga Cvetkovski. "FEM Modelling and Analysis of Single Sided Linear Synchronous Motor." In 7th Symposium on Applied Electromagnetics SAEM`18. Unviersity of Maribor Press, 2019. http://dx.doi.org/10.18690/978-961-286-241-1.23.
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Liu, G. R. "On Smoothed Finite Element Methods." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-62239.
Повний текст джерелаАнотація:
The paper presents an overview of the smoothed finite element methods (S-FEM) which are formulated by combining the existing standard FEM with the strain smoothing techniques used in the meshfree methods. The S-FEM family includes five models: CS-FEM, NS-FEM, ES-FEM, FS-FEM and α-FEM (a combination of NS-FEM and FEM). It was originally formulated for problems of linear elastic solid mechanics and found to have five major properties: (1) S-FEM models are always “softer” than the standard FEM, offering possibilities to overcome the so-called overly-stiff phenomenon encountered in the standard the FEM models; (2) S-FEM models give more freedom and convenience in constructing shape functions for special purposes or enrichments (e.g, various degree of singular field near the crack-tip, highly oscillating fields, etc.); (3) S-FEM models allow the use of distorted elements and general n-sided polygonal elements; (4) NS-FEM offers a simpler tool to estimate the bounds of solutions for many types of problems; (5) the αFEM can offer solutions of very high accuracy. With these properties, the S-FEM has rapidly attracted interests of many. Studies have been published on theoretical aspects of S-FEMs or modified S-FEMs or the related numerical methods. In addition, the applications of the S-FEM have been also extended to many different areas such as analyses of plate and shell structures, analyses of structures using new materials (piezo, composite, FGM), limit and shakedown analyses, geometrical nonlinear and material nonlinear analyses, acoustic analyses, analyses of singular problems (crack, fracture), and analyses of fluid-structure interaction problems.
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Darabi, S., and M. Ardebili. "Analysis of linear switched reluctance motor with longitudinal flux linkage using 2D-FEM compared to 3D-FEM." In Technologies Conference (PEDSTC). IEEE, 2011. http://dx.doi.org/10.1109/pedstc.2011.5742499.
Повний текст джерелаЗвіти організацій з теми "Linear FEM analyse"
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Rhymer, Donald W. Stress Intensity Solutions of Thermally Induced Cracks in Combustor Liner Hot Spots Using Finite Element Analysis (FEA). Fort Belvoir, VA: Defense Technical Information Center, December 2005. http://dx.doi.org/10.21236/ada450027.
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Lers, Amnon, Majid R. Foolad, and Haya Friedman. genetic basis for postharvest chilling tolerance in tomato fruit. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7600014.bard.
Повний текст джерелаАнотація:
ABSTRACT Postharvest losses of fresh produce are estimated globally to be around 30%. Reducing these losses is considered a major solution to ensure global food security. Storage at low temperatures is an efficient practice to prolong postharvest performance of crops with minimal negative impact on produce quality or human health and the environment. However, many fresh produce commodities are susceptible to chilling temperatures, and the application of cold storage is limited as it would cause physiological chilling injury (CI) leading to reduced produce quality. Further, the primary CI becomes a preferred site for pathogens leading to decay and massive produce losses. Thus, chilling sensitive crops should be stored at higher minimal temperatures, which curtails their marketing life and in some cases necessitates the use of other storage strategies. Development of new knowledge about the biological basis for chilling tolerance in fruits and vegetables should allow development of both new varieties more tolerant to cold, and more efficient postharvest storage treatments and storage conditions. In order to improve the agricultural performance of modern crop varieties, including tomato, there is great potential in introgression of marker-defined genomic regions from wild species onto the background of elite breeding lines. To exploit this potential for improving tomato fruit chilling tolerance during postharvest storage, we have used in this research a recombinant inbred line (RIL) population derived from a cross between the red-fruited tomato wild species SolanumpimpinellifoliumL. accession LA2093 and an advanced Solanum lycopersicumL. tomato breeding line NCEBR-1, developed in the laboratory of the US co-PI. The original specific objectives were: 1) Screening of RIL population resulting from the cross NCEBR1 X LA2093 for fruit chilling response during postharvest storage and estimation of its heritability; 2) Perform a transcriptopmic and bioinformatics analysis for the two parental lines following exposure to chilling storage. During the course of the project, we learned that we could measure greater differences in chilling responses among specific RILs compared to that observed between the two parental lines, and thus we decided not to perform transcriptomic analysis and instead invest our efforts more on characterization of the RILs. Performing the transcriptomic analysis for several RILs, which significantly differ in their chilling tolerance/sensitivity, at a later stage could result with more significant insights. The RIL population, (172 lines), was used in field experiment in which fruits were examined for chilling sensitivity by determining CI severity. Following the field experiments, including 4 harvest days and CI measurements, two extreme tails of the response distribution, each consisting of 11 RILs exhibiting either high sensitivity or tolerance to chilling stress, were identified and were further examined for chilling response in greenhouse experiments. Across the RILs, we found significant (P < 0.01) correlation between field and greenhouse grown plants in fruit CI. Two groups of 5 RILs, whose fruits exhibited reproducible chilling tolerant/sensitive phenotypes in both field and greenhouse experiments, were selected for further analyses. Numerous genetic, physiological, biochemical and molecular variations were investigated in response to postharvest chilling stress in the selected RILs. We confirmed the differential response of the parental lines of the RIL population to chilling stress, and examined the extent of variation in the RIL population in response to chilling treatment. We determined parameters which would be useful for further characterization of chilling response in the RIL population. These included chlorophyll fluorescence Fv/Fm, water loss, total non-enzymatic potential of antioxidant activity, ascorbate and proline content, and expression of LeCBF1 gene, known to be associated with cold acclimation. These parameters could be used in continuation studies for the identification and genetic mapping of loci contributing to chilling tolerance in this population, and identifying genetic markers associated with chilling tolerance in tomato. Once genetic markers associated with chilling tolerance are identified, the trait could be transferred to different genetic background via marker-assisted selection (MAS) and breeding. The collaborative research established in this program has resulted in new information and insights in this area of research and the collaboration will be continued to obtain further insights into the genetic, molecular biology and physiology of postharvest chilling tolerance in tomato fruit. The US Co-PI, developed the RIL population that was used for screening and measurement of the relevant chilling stress responses and conducted statistical analyses of the data. Because we were not able to grow the RIL population under field conditions in two successive generations, we could not estimate heritability of response to chilling temperatures. However, we plan to continue the research, grow the RIL progeny in the field again, and determine heritability of chilling tolerance in a near future. The IS and US investigators interacted regularly and plan to continue and expand on this study, since combing the expertise of the Co-PI in genetics and breeding with that of the PI in postharvest physiology and molecular biology will have great impact on this line of research, given the significant findings of this one-year feasibility project.
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Lers, Amnon, and Pamela J. Green. LX Senescence-Induced Ribonuclease in Tomato: Function and Regulation. United States Department of Agriculture, September 2003. http://dx.doi.org/10.32747/2003.7586455.bard.
Повний текст джерелаАнотація:
Natural leaf senescence, which occurs even when growth conditions are near optimal, has a negative influence on yield. Postharvest induced senescence contributes to the losses of quality in flowers, foliage, and vegetables. Strategies designed to control the senescence process in crop plants could therefore have great applied significance. However, the successful design of such strategies requires a better insight into the senescence machinery and control in higher plants. A main feature of senescence is the hydrolysis of macromolecules by hydrolases of various types such as ribonucleases (RNases) and proteases. Previously we had identified and characterized the tomato LX RNase gene demonstrating its transcript to be highly and specifically induced during senescence. This reported study was focused on LX but also had broadened our research to other senescence-associated nucleic acids degrading enzymes to learn about their function and the regulation of their encoding genes. Beside tomato we used parsley and Arabidopsis for the study of: the bi-functional nuclease which has a role in senescence. The study of different senescence- associated nucleases in few plant systems will allow a more general view on function and regulation of these enzymes in senescence. The specific original proposed objectives included: 1. Study the consequences of alterations in LX RNase level on tomato leaf senescence and general development; 2. Analyze stimuli which may participate in senescence-specific activation of the LX gene; 3. Clone the senescence-associated BFNI nuclease gene homologue from tomato. 4. Further characterize the sequences required for senescence-specific gene expression. Homozygous transgenic plants in which LX gene was either inhibited or over-expressed were generated. In both of these LX mutated plants no major phenotypic consequences were observed, which may suggests that LX is not essential for plant growth under optimal growth conditions. Lack of any abnormalities in the LX over-expressing lines suggests that special system exist to allow function of the RNase only when needed. Detailed analyses of growth under stress and consequences to RNA metabolism are underway. We have analyzed LX expression on the protein level demonstrating that it is involved also in petal senescing. Our results suggest that LX is responding to complex regulation involving developmental, organ dependent factors and responds differently to hormonal or environmental stimuli in the different plant organs. The cloned 1.4 kb promoter was cloned and its analysis revealed that probably not all required elements for senescence induction are included. Biochemical analysis of senescence-associated be-functional nucleases in the different plants, tomato, parsley and Arabidopsis, suggests they belong to a sub-class within the type I plant nucleases. The parsley PcNUC1/2 nuclease protein was purified from senescing leaves its and activity was studied in vitro revealing endo-, double strand, nucleolytic activity and exo-nucleolytic activity. Its encoding gene was cloned and found to be induced on the mRNA level. The promoter of the related Arabidopsis BFNI nuclease was shown in both tomato and Arabidopsis to be able and direct senescence-specific expression suggesting that, at least part, the gene is regulated on the transcriptional level and that the mechanism for this senescence-specific regulation is conserved between different plants. Few plants in which the BFNI gene is mutated were identified which are subjected now to detailed analysis. Our results suggest that the senescence-related nucleic acid degrading enzymes share similarities in both function and regulation between different plants and possibly have important functions in processes un-related to senescence. Still, the function of these enzymes, at least in some cases is not essential to plant development under optimal growth conditions. We are now at the stage which permits in depth investigation of the specific functions and mode of molecular regulation of senescence-associated nucleases with the aid of the research tools developed. The isolated senescence-specific promoter, shown to be active in heterologous plant system, could be utilized in agricultural-related biotechnological applications for retardation of senescence.
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Zamir, Dani, Steven Tanksley, and Robert Fluhr. Cloning a Fusarium Resistance Gene in Tomato Based on Knowledge of its Map Position. United States Department of Agriculture, July 1995. http://dx.doi.org/10.32747/1995.7604934.bard.
Повний текст джерелаАнотація:
The objectives of this project were to develop the tools and methodologies for positional cloning of genes in tomato and apply them for the cloning a Fusarium resistance gene - I2.. The feasibility of positional cloning of disease resistance genes was demonstrated for Pto which confers resistance to pseudomonas (Martin et al. 1993). The Fusarium resistance gene was mapped genetically and physically and was found to be in close proximity to TG 105 (Segal et al. 1992). To obtain fine mapping of gene I2, and additional target genes in future projects, a high density linkage map was developed (Tanksley et al. 1992; Broun and Tanksley 1993). In addition two permanent mapping populations were constructed: a recombinant inbred (Paran et al. 1995; Zamir et al. 1993) and an introgression line population (Eshed et al. 1992; Eshed and Zamir 1994). Using these resources we determined that the I2 locus shows complete co-segregation, down to a resolution of a few Kb, with SL8 which shows architectural similarity with other plant resistance genes. Transformation and complementation analysis is in progress (Ori et al. in preparation).
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Kodupuganti, Swapneel R., Sonu Mathew, and Srinivas S. Pulugurtha. Modeling Operational Performance of Urban Roads with Heterogeneous Traffic Conditions. Mineta Transportation Institute, January 2021. http://dx.doi.org/10.31979/mti.2021.1802.
Повний текст джерелаАнотація:
The rapid growth in population and related demand for travel during the past few decades has had a catalytic effect on traffic congestion, air quality, and safety in many urban areas. Transportation managers and planners have planned for new facilities to cater to the needs of users of alternative modes of transportation (e.g., public transportation, walking, and bicycling) over the next decade. However, there are no widely accepted methods, nor there is enough evidence to justify whether such plans are instrumental in improving mobility of the transportation system. Therefore, this project researches the operational performance of urban roads with heterogeneous traffic conditions to improve the mobility and reliability of people and goods. A 4-mile stretch of the Blue Line light rail transit (LRT) extension, which connects Old Concord Rd and the University of North Carolina at Charlotte’s main campus on N Tryon St in Charlotte, North Carolina, was considered for travel time reliability analysis. The influence of crosswalks, sidewalks, trails, greenways, on-street bicycle lanes, bus/LRT routes and stops/stations, and street network characteristics on travel time reliability were comprehensively considered from a multimodal perspective. Likewise, a 2.5-mile-long section of the Blue Line LRT extension, which connects University City Blvd and Mallard Creek Church Rd on N Tryon St in Charlotte, North Carolina, was considered for simulation-based operational analysis. Vissim traffic simulation software was used to compute and compare delay, queue length, and maximum queue length at nine intersections to evaluate the influence of vehicles, LRT, pedestrians, and bicyclists, individually and/or combined. The statistical significance of variations in travel time reliability were particularly less in the case of links on N Tryon St with the Blue Line LRT extension. However, a decrease in travel time reliability on some links was observed on the parallel route (I-85) and cross-streets. While a decrease in vehicle delay on northbound and southbound approaches of N Tryon St was observed in most cases after the LRT is in operation, the cross-streets of N Tryon St incurred a relatively higher increase in delay after the LRT is in operation. The current pedestrian and bicycling activity levels seemed insignificant to have an influence on vehicle delay at intersections. The methodological approaches from this research can be used to assess the performance of a transportation facility and identify remedial solutions from a multimodal perspective.
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McKinnon, Mark B., and Daniel Madrzykowski. Four Firefighters Burned in Residential House Fire - Georgia. UL's Fire Safety Research Institute, June 2022. http://dx.doi.org/10.54206/102376/gekk4148.
Повний текст джерелаАнотація:
On September 3, 2018, two career Fire Lieutenants and two career Firefighters suffered burn injuries as a result of a residential structure fire. On September 10, 2018, personnel representing several other fire departments in the area, including a member of the Fire Safety Research Institute (FSRI) Advisory Board visited the fire scene to document the incident and collect material samples from the structure. The narrative and analysis presented in this report rely on the photographs and evidence collected on September 10, 2018, dispatch transcript [5] and videos recorded at the time of the incident, and interviews conducted by a local investigator between September 3, 2018 and September 7, 2018 with fire service personnel involved in the incident and the resident of the structure [6]. The LaGrange Fire Department invited FSRI to study this incident as part of FSRI’s Near-Miss Project which is supported by a DHS/FEMA Assistance to Firefighters Grant. The goal of this project is to enhance the safety and situational awareness of the fire service by applying fire dynamics research results to near-miss or line of duty injury fire incidents. By identifying factors that contributed to the incident, perhaps future incidents may be prevented. FSRI’s analysis of this incident will apply research results and utilize fire research tools, such as computer fire models, to examine key fire phenomena and tactical outcomes. This report will explain the incident, what occurred, why it occurred, and what can be done differently in the future to result in a more favorable outcome
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Mayfield, Colin. Capacity Development in the Water Sector: the case of Massive Open On-line Courses. United Nations University Institute for Water, Environment and Health, January 2017. http://dx.doi.org/10.53328/mwud6984.
Повний текст джерелаАнотація:
The Sustainable Development Goal 6 targets are all dependent on capacity development as outlined in SDG 6a “Expand international cooperation and capacity-building support to developing countries in water- and sanitation related activities and programmes “. Massive Open On-line Courses (MOOCs) and distance learning in general have a significant role to play in this expansion. This report examines the role that MOOCs and similar courses could play in capacity development in the water sector. The appearance of MOOCs in 2010/11 led within 4 years to a huge increase in this type of course and in student enrollment. Some problems with student dropout rates, over-estimating the transformational and disruptive nature of MOOCs and uncertain business models remain, but less “massive” MOOCs with more engaged students are overcoming these problems. There are many existing distance learning courses and programmes in the water sector designed to train and/ or educate professionals, operators, graduate and undergraduate students and, to a lesser extent, members of communities dealing with water issues. There are few existing true MOOCs in the water sector. MOOCs could supply significant numbers of qualified practitioners for the water sector. A suite of programmes on water-related topics would allow anyone to try the courses and determine whether they were appropriate and useful. If they were, the students could officially enroll in the course or programme to gain a meaningful qualification or simply to upgrade their qualifications. To make MOOCs more relevant to education and training in the water sector an analysis of the requirements in the sector and the potential demand for such courses is required. Cooperation between institutions preparing MOOCs would be desirable given the substantial time and funding required to produce excellent quality courses. One attractive model for cooperation would be to produce modules on all aspects of water and sanitation dealing with technical, scientific, social, legal and management topics. These should be produced by recognized experts in each field and should be “stand-alone” or complete in themselves. If all modules were made freely available, users or mentors could assemble different MOOCs by linking relevant modules. Then extracts, simplified or less technical versions of the modules could then be used to produce presentations to encourage public participation and for other training purposes. Adaptive learning, where course materials are more tailored to individual students based on their test results and reactions to the material, can be an integral part of MOOCs. MOOCs efficiently provide access to quality courses at low or no cost to students around the world, they enable students to try courses at their convenience, they can be tailored to both professional and technical aspects, and they are very suitable to provide adaptive learning courses. Cooperation between institutions would provide many course modules for the water sector that collectively could provide excellent programmes to address the challenges of capacity development for SDG 6 and other issues within the water sector.
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Olsson, Olle. Industrial decarbonization done right: identifying success factors for well-functioning permitting processes. Stockholm Environment Institute, November 2021. http://dx.doi.org/10.51414/sei2021.034.
Повний текст джерелаАнотація:
1 Introduction 1.1 The urgency of industrial decarbonization The last few years have seen several of the world’s largest carbon dioxide-emitting countries and leading heavy industry companies committing to mid-century net-zero targets (Buckley 2021; Denyer and Kashiwagi 2020; McCurry 2020; Myers 2020). Consequently, the discussion on economy-wide transition to net-zero is accelerating, with focus shifting from “if” to “when” and “how”, even for heavy industry sectors like steel, cement and chemicals. This makes it increasingly urgent to analyse not just whether it is technologically feasible to decarbonize heavy industry, but also investigate issues more directly related to practical implementation. This includes site-specific planning, infrastructure availability, and consultation with local authorities and other stakeholders. Many of the latter considerations are formalized as part of the permitting processes that are an essential vehicle to ensure that industrial interests are balanced against interests of society at large. However, doing this balancing act can turn out to be very complicated and associated with uncertainties as to their outcome, as well as being demanding in resources and time. At the same time, to ensure broad buy-in and support from society, the investments needed must be implemented in a way that takes a broad spectrum of sustainability concerns into account, not just climate change mitigation. A key question is if and how permitting processes can run more smoothly and efficiently while still ensuring inclusive consultations, fair procedures and adherence to legal certainty. This policy brief discusses this question from the starting point of Swedish conditions, but many of the points raised will be relevant for a broader international discussion on taking industrial decarbonization to implementation. 1.2 Industrial transition and permitting processes in Sweden Decarbonization of the industrial sector in Sweden essentially entails a relatively small number of investment projects in the cement, steel, petrochemical and refinery sectors, where the vast majority of carbon emissions are concentrated (Karltorp et al. 2019; Nykvist et al. 2020). However, while few in number, the size of these investments means that their implementation will by necessity become relevant to many other parts of society. In connection with the increasing focus on how to implement industrial decarbonization in Sweden, discussions about permitting processes have been brought higher up on the agenda. While there has been an active discussion on permitting processes in Sweden for quite some time, it has primarily been focused on aspects related to mining and wind power (Larsen et al. 2017; Raitio et al. 2020). The last few years have, however, focused increasingly on industrial projects, in particular related to a proposed – though eventually cancelled – expansion of an oil refinery in the southwestern part of the country (Blad 2020). In terms of political discussions, both the governmental initiative Fossil-free Sweden (2020) and the Swedish Climate Policy Council (2020) emphasize that permitting processes need to become faster in order for Sweden’s industrial transition to be implemented in line with the time plan set by the 2017 Swedish Climate Act. Business representatives and organizations are also voicing concerns about the slow speed of permitting (Balanskommissionen 2019; Jacke 2018). At the same time, criticism has been raised that much of the environmental damage done in Sweden comes from activities conducted within limits set by environmental permits, which could be a flaw in the system (Malmaeus and Lindblom 2019). Finally, recent public inquiries have also discussed permitting processes.
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Fromm, Hillel, Paul Michael Hasegawa, and Aaron Fait. Calcium-regulated Transcription Factors Mediating Carbon Metabolism in Response to Drought. United States Department of Agriculture, June 2013. http://dx.doi.org/10.32747/2013.7699847.bard.
Повний текст джерелаАнотація:
Original objectives: The long-term goal of the proposed research is to elucidate the transcription factors, genes and metabolic networks involved in carbon metabolism and partitioning in response to water deficit. The proposed research focuses on the GTLcalcium/calmodulinbindingTFs and the gene and metabolic networks modulated by these TFs in Arabidopsis thaliana. The specific objectives are as follows. Objective-1 (USA): Physiological analyses of GTL1 loss- and gain-of-function plants under water sufficient and drought stress conditions Objective 2 (USA / Israel-TAU): Characterizion of GTL target genes and bioinformatic analysis of data to eulcidate gene-network topology. Objective-3 (Israel-TAU): Regulation of GTLmediated transcription by Ca²⁺/calmodulin: mechanism and biological significance. Objective-4 (Israel-BGU): Metabolic networks and carbon partitioning in response to drought. Additional direction: In the course of the project we added another direction, which was reported in the 2nd annual report, to elucidate genes controlling drought avoidance. The TAU team has isolated a few unhydrotropic (hyd) mutants and are in the process of mapping these mutations (of hyd13 and hyd15; see last year's report for a description of these mutants under salt stress) in the Arabidopsis genome by map-based cloning and deep sequencing. For this purpose, each hyd mutant was crossed with a wild type plant of the Landsberg ecotype, and at the F2 stage, 500-700 seedlings showing the unhydrotropic phenotype were collected separately and pooled DNA samples were subkected to the Illumina deep sequencing technology. Bioinformatics were used to identify the exact genomic positions of the mutations (based on a comparison of the genomic sequences of the two Arabidopsis thaliana ecotypes (Columbia and Landsberg). Background: To feed the 9 billion people or more, expected to live on Earth by the mid 21st century, the production of high-quality food must increase substantially. Based on a 2009 Declaration of the World Summit on Food Security, a target of 70% more global food production by the year 2050 was marked, an unprecedented food-production growth rate. Importantly, due to the larger areas of low-yielding land globally, low-yielding environments offer the greatest opportunity for substantial increases in global food production. Nowadays, 70% of the global available water is used by agriculture, and 40% of the world food is produced from irrigated soils. Therefore, much needs to be done towards improving the efficiency of water use by plants, accompanied by increased crop yield production under water-limiting conditions. Major conclusions, solutions and achievements: We established that AtGTL1 (Arabidopsis thaliana GT-2 LIKE1) is a focal determinant in water deficit (drought) signaling and tolerance, and water use efficiency (WUE). The GTL1 transcription factor is an upstream regulator of stomatal development as a transrepressor of AtSDD1, which encodes a subtilisin protease that activates a MAP kinase pathway that negatively regulates stomatal lineage and density. GTL1 binds to the core GT3 cis-element in the SDD1 promoter and transrepresses its expression under water-sufficient conditions. GTL1 loss-of-function mutants have reduced stomatal number and transpiration, and enhanced drought tolerance and WUE. In this case, higher WUE under water sufficient conditions occurs without reduction in absolute biomass accumulation or carbon assimilation, indicating that gtl1-mediated effects on stomatal conductance and transpiration do not substantially affect CO₂ uptake. These results are proof-of-concept that fine-tuned regulation of stomatal density can result in drought tolerance and higher WUE with maintenance of yield stability. Implications: Accomplishments during the IS-4243-09R project provide unique tools for continued discovery research to enhance plant drought tolerance and WUE.
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Delwiche, Michael, Boaz Zion, Robert BonDurant, Judith Rishpon, Ephraim Maltz, and Miriam Rosenberg. Biosensors for On-Line Measurement of Reproductive Hormones and Milk Proteins to Improve Dairy Herd Management. United States Department of Agriculture, February 2001. http://dx.doi.org/10.32747/2001.7573998.bard.
Повний текст джерелаАнотація:
The original objectives of this research project were to: (1) develop immunoassays, photometric sensors, and electrochemical sensors for real-time measurement of progesterone and estradiol in milk, (2) develop biosensors for measurement of caseins in milk, and (3) integrate and adapt these sensor technologies to create an automated electronic sensing system for operation in dairy parlors during milking. The overall direction of research was not changed, although the work was expanded to include other milk components such as urea and lactose. A second generation biosensor for on-line measurement of bovine progesterone was designed and tested. Anti-progesterone antibody was coated on small disks of nitrocellulose membrane, which were inserted in the reaction chamber prior to testing, and a real-time assay was developed. The biosensor was designed using micropumps and valves under computer control, and assayed fluid volumes on the order of 1 ml. An automated sampler was designed to draw a test volume of milk from the long milk tube using a 4-way pinch valve. The system could execute a measurement cycle in about 10 min. Progesterone could be measured at concentrations low enough to distinguish luteal-phase from follicular-phase cows. The potential of the sensor to detect actual ovulatory events was compared with standard methods of estrus detection, including human observation and an activity monitor. The biosensor correctly identified all ovulatory events during its testperiod, but the variability at low progesterone concentrations triggered some false positives. Direct on-line measurement and intelligent interpretation of reproductive hormone profiles offers the potential for substantial improvement in reproductive management. A simple potentiometric method for measurement of milk protein was developed and tested. The method was based on the fact that proteins bind iodine. When proteins are added to a solution of the redox couple iodine/iodide (I-I2), the concentration of free iodine is changed and, as a consequence, the potential between two electrodes immersed in the solution is changed. The method worked well with analytical casein solutions and accurately measured concentrations of analytical caseins added to fresh milk. When tested with actual milk samples, the correlation between the sensor readings and the reference lab results (of both total proteins and casein content) was inferior to that of analytical casein. A number of different technologies were explored for the analysis of milk urea, and a manometric technique was selected for the final design. In the new sensor, urea in the sample was hydrolyzed to ammonium and carbonate by the enzyme urease, and subsequent shaking of the sample with citric acid in a sealed cell allowed urea to be estimated as a change in partial pressure of carbon dioxide. The pressure change in the cell was measured with a miniature piezoresistive pressure sensor, and effects of background dissolved gases and vapor pressures were corrected for by repeating the measurement of pressure developed in the sample without the addition of urease. Results were accurate in the physiological range of milk, the assay was faster than the typical milking period, and no toxic reagents were required. A sampling device was designed and built to passively draw milk from the long milk tube in the parlor. An electrochemical sensor for lactose was developed starting with a three-cascaded-enzyme sensor, evolving into two enzymes and CO2[Fe (CN)6] as a mediator, and then into a microflow injection system using poly-osmium modified screen-printed electrodes. The sensor was designed to serve multiple milking positions, using a manifold valve, a sampling valve, and two pumps. Disposable screen-printed electrodes with enzymatic membranes were used. The sensor was optimized for electrode coating components, flow rate, pH, and sample size, and the results correlated well (r2= 0.967) with known lactose concentrations.