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1
Porter, Craig Thomas. "Computational modelling of cyclic peptides incorporating reverse turn peptidomimetics". Thesis, University of Southampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243122.
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Closen, Max. "Self-tapping screw assemblies under monotonic and reverse cyclic load". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42780.
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In the past century old-growth forests in Canada and the USA provided sufficiently large, clear wooden construction material which have been extensively used. Today, the importance of high-quality structural timber and wood products has increased by far. This increase in demand for high-quality timber and wood products can only be satisfied with second-growth wood, some remaining old-growth forests, and of course engineered wood products. The performance of these materials in structures is, however, largely influenced by the capacity of connections. The envelope in timber construction can only be pushed forward if research on mechanical fasteners and connections that are strong, reliable and cost efficient is conducted. Primary focus of research must address the inherent tensile and shear weaknesses of wood perpendicular and parallel to the wood grain.
The thesis presented here experimentally investigates the performance of newly evolved structural self-tapping full thread wood screws as a primary fastener in Canadian Douglas-fir glulam and Cross-Laminated-Timber. The screws as primary fasteners were investigated in a commonly used shear connection and a recently developed moment resisting assembly under reverse cyclic load. Both connection systems utilize the high withdrawal resistance and tensile strength of the fastener with inclined (screw-in angles between 30° and 45°) arrangements. The inclined arrangement allows force transfer along the fastener axis and therefore reduces perpendicular to grain splitting and parallel to grain shear failure and provides high connection capacities and stiffness. The results show that structural self-tapping wood screws can effectively be used as primary connector under reverse cyclic loading conditions. In addition to the screw’s superior withdrawal resistance and tensile strength the research showed that self-tapping screws can be applied efficiently with commonly available machinery and tools.
3
Aghniaey, Nima. "Behaviour of Self Consolidating Steel Fiber Reinforced Concrete Beams Under Reversed Cyclic Loading". Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/23785.
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Concrete is a very weak and brittle material in tension. It has been shown in previous researches that the addition of steel fibers to a concrete matrix can improve this behavior. The ability of fibers to control and redistribute stresses after cracking results in a number of improvements in the structural behaviour of concrete. A review of existing literature shows that the addition of steel fibers enhances concrete’s tensile resistance, crack control properties, ductility and damage tolerance. In beams, fibers can transform brittle shear response into a flexural response and promote ductility, thereby allowing for a full or partial replacement of traditional shear reinforcement. The enhanced shear capacity, ductility and damage tolerance of Steel Fiber Reinforced Concrete (SFRC) can also potentially be used to relax seismic detailing requirements in frames by partially replacing the required transverse reinforcement in the plastic hinge regions of RC beams.
One of the drawbacks associated with SFRC is that the addition of steel fibers to a traditional concrete mix at high fiber contents can result in workability problems. The combined use of Self-Consolidating Concrete (SCC) and fibers can solve this problem and facilitate placement for a wider range of structural applications.
Although several studies have been conducted on the behaviour of SFRC beams subjected to monotonic loading, there is limited research on the behaviour of SFRC beams under cyclic or reverse-cyclic loading. This thesis presents the results of an experimental and analytical study conducted on nine SFRC beam specimens tested under load reversals. The main objective of this research program was to investigate the effect of fibers on structural behaviour and to examine the ability of steel fibers to replace transverse reinforcement. The experimental and analytical results show that use of fibers results in several improvements in behaviour, including enhanced damage tolerance and post-peak ductility. The results also show that steel fibers can potentially be used to allow for a reduction of transverse reinforcement in beams, however further research is required.
4
Graham, Drew Abram. "Performance of log shear walls and lag screw connections subjected to monotonic and reverse-cyclic loading". Online access for everyone, 2007. http://www.dissertations.wsu.edu/Thesis/Spring2007/d%5Fgraham%5F030607.pdf.
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Albright, Dustin Graham. "The Effects of Bolt Spacing on the Performance of Single-Shear Timber Connections Under Reverse-Cyclic Loading". Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/34324.
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Much previous experimentation related to wood structures has employed monotonic loading to replicate static situations. However, instances of natural hazards have raised interest in the response of structural connections to dynamic loads. This increased interest led the Consortium of Universities for Research in Earthquake Engineering (CUREE) to develop a testing protocol for reverse-cyclic loading, which involves cycling loads through zero in order to test specimens in both tension and compression. With the CUREE testing protocol in place, recent research has been devoted to understanding the effects of reverse-cyclic loading on multiple-fastener connections.
Experimentation by Heine (2001), Anderson (2002), Billings (2004) and others contributed to a better understanding of bolted connection behavior under reverse-cyclic loading. However, some questions remained. Billings was unable to consistently produce yield modes III and IV, meaning that her suggested bolt spacing of seven times the bolt diameter (7D) could not be applied to connections subject to these yield modes without further testing. In addition, the work of Anderson and Billings raised questions regarding the proper measurement of bending yield strength in bolts and the relationship between the bending yield strength and the tensile yield strength. These topics are each addressed by this project and thesis report.
Results of the connection testing presented in this report can be used in conjunction with the work of Anderson and Billings to critically evaluate the 4D between-bolt spacing recommended by the National Design Specification (NDS) for Wood Construction (AF&PA, 2001). Results of the bolt testing provide a supplement to the search for a reliable method for the measurement of bending yield strength in bolts.Master of Science
6
Knudson, Caleb Jesse. "Investigation into the effects of variable row spacing in bolted timber connections subjected to reverse cyclic loading". Online access for everyone, 2006. http://www.dissertations.wsu.edu/Thesis/Fall2006/c_knudson_110906.pdf.
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Ntshongontshi, Nomaphelo. "Cytochrome P450-3A4/copper-poly(propylene imine)- polypyrrole star co-polymer Nanobiosensor system for delavirdine – a non-nucleoside reverse transcriptase inhibitor HIV drug". University of the Western Cape, 2014. http://hdl.handle.net/11394/4446.
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>Magister Scientiae - MScHIV and AIDS are among the world's pandemics that pose serious concern to almost every individual in the world. With the current level of availability of anti-retroviral (ARV) drugs and the ease of accessibility of treatment in many countries such as South Africa, the disease can be controlled by suppressing the viral load of an infected individual. These anti HIV drugs such as delavirdine are metabolised by enzymes which are found in the liver microsomes, particularly those of the cytochrome P450 family. Due to the fact that the metabolic rate of a patient determines the effect of the drug, the drug could either have a beneficial or an adverse effect once it is administered. It is therefore imperative that the metabolic profile of a patient is determined at point-of-care is necessary for proper dosing of the ARV drugs. In this project a nanobiosensor system was devised and used for the determination of the metabolism of delavirdine, a non-nucleoside reverse transcriptase inhibitor (NNRTI) ARV drug. The nanobiosensor was prepared by the entrapment of the isoenzyme CYP3A4 into a pre-formed electro active carrier matrice consisting of a dendrimeric copper generation-2 poly (propylene imine)-co-polypyrrole star copolymer (Cu(G2PPI)-co-PPy). The metallo-dendrimer was used as a host for the enzyme and provided thenecessary bio-compatible environment that allowed the direct transfer of electrons between the enzyme's active centres and platinum electrode surface. Copper was the choice of metal used in the study due to its properties. Copper is a malleable, ductile and a good conductor of both heat and electricity. It is a better conductor than most metals. Silver which also belongs to group 1b in the periodic table is a better electrical conductor than copper but copper has better corrosion resistance and is a more abundant and hence it is a cheaper material to use. Cu(G2PPI)-co-PPy was prepared by the incorporation of the copper metal into the G2PPI and the electropolymerization of pyrrole onto the Cu(G2PPI). The incorporation of Cu into G2PPI was determined by FTIR which did not show the presence of the Cu but showed an increase in the intensities of the peaks after the incorporation. The surface morphology of Cu (G2PPI) was confirmed by the use of HRSEM which showed a difference in the surface morphology of the dendrimer moiety with the addition of the copper metal. The HRSEM images after Cu incorporation resulted in the change from rough surface to smooth surface with open cavities which were essential for the entrapment of the biological systems (CYP3A4). Energy dispersive spectrometry (EDS) and HRTEM were used to confirm the presence of spherically shaped copper nanoparticles in the Cu (G2PPI) and were found to have a size distribution of 12-17 nm with an average particle size of 15nm. The star copolymer (Cu(G2PPI)-co-PPy) was characterised using cyclic voltammetrywhere it was confirmed that the material was electroactive and conducting due to electron movement along the polymer chain. A diffusion co-efficient (D₀) value of 8.64 x 10⁻⁵ cm²/s was determined for the material indicating a slow electron transfer kinetics within the diffusion layer. The constructed nanobiosensor was developed using copper poly (propylene imine) – polypyrrole star copolymer, bovine serum albumin and glutaraldehyde coupled to the enzyme CYP3A4. The resultant nanobiosensor parameters include a dynamic linear range (DLR) of 0.01-0.06 nM, a limit of detection (LOD) of 0.025 nM and a sensitivity value of0.379 μA/nM.
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Billings, Mary Anna. "Investigation of the Effects of Spacing between Bolts in a Row in a Single-Shear Timber Connection Subjected to Reverse Cyclic Loading". Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/35757.
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This thesis presents the results of testing to determine if spacing between bolts in a multiple-bolt, single-shear connection subjected to natural hazard loading affects seven strength and serviceability parameters: maximum load, failure load, E.E.P. yield load, 5% offset load, elastic stiffness, E.E.P. energy, and ductility ratio. This research also determines if a statistical difference exists between previously published research for 4D spacing as compared to results produced by this research for five alternate spacings: 8D, 7D, 6D, 5D, and 3D. Finally, this research determines which of the spacings examined: 8D, 7D, 6D, 5D, 3D; produced the most optimal results for each examined strength and serviceability parameter where optimization is based on economy and performance.
Three connection configurations with five different spacings between bolts were subjected to reverse cyclic loading for a total of one hundred and fifty tests. The reverse cyclic protocol was based on recommendations by the Consortium of Universities for Research in Earthquake Engineering (CUREE) for testing woodframe structures. The same connection configurations were also subjected to monotonic loading for an additional forty-five tests.
Results of this research can be used to evaluate the current design recommendation presented in the National Design Specification (NDS) for Wood Construction (AF&PA, 2001) of spacing bolts at four times the bolt diameter (4D) to determine if a different spacing should be recommended for natural hazard loading conditions.
Master of Science
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Mulla, Salah. "Effect of Cyclic Loading on Screw Joint Stability of Implants with Angled Screw Channel Crowns". The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1593090425010651.
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Marcus, Adam Wade. "New combinatorial techniques for nonlinear orders". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24685.
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Thesis (Ph.D.)--Mathematics, Georgia Institute of Technology, 2008.Committee Chair: Prasad Tetali; Committee Member: Dana Randall; Committee Member: Robin Thomas; Committee Member: Vijay Vazirani; Committee Member: William T. Trotter
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Ni, Chun. "Behavior of nailed timber joints under reversed cyclic load". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq23869.pdf.
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Khadilkar, Yogesh S. "Reverse supply chain life cycle inventory analysis /". Cincinnati, Ohio : University of Cincinnati, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1098665167.
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KHADILKAR, YOGESH SUDHIR Mr. "REVERSE SUPPLY CHAIN: LIFE CYCLE INVENTORY ANALYSIS". University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1098665167.
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渠瑾 y Jin Qu. "Novel helices, reversed turns and cyclic peptides containing alpha-aminoxy acids". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B3124225X.
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Vojoudi, Mehrabani Reza [Verfasser]. "Reinforced Concrete Beams Subjected to Reversed Cyclic Shear / Reza Vojoudi Mehrabani". Aachen : Shaker, 2017. http://d-nb.info/1149278773/34.
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Qu, Jin. "Novel helices, reversed turns and cyclic peptides containing alpha-aminoxy acids /". Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22713360.
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Bakis, Charles E. "Fatigue behavior of notched carbon epoxy laminates during reversed cyclic loads". Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53903.
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The relationships between fatigue damage, stress redistribution, and residual stiffness and strength were investigated for notched graphite epoxy laminates during fulIy-reversed cyclic loads. Two material systems, AS4/3501-6 and AS4/1808, two lamination arrangements, (0,45,90,-45)s₄ and (0,45,0,-45)s₄, and two notch configurations, central hole and opposing semi-circular edge notches, were used to obtain a fundamental understanding of the fatigue effect in specimens under low and high cycle lifetimes. Damage was evaluated with penetrant-enhanced X-ray radiography and Iaminate deply. Tensile and compressive residual strengths were measured at three stages of damage development. A recently developed nondestructive testing technique, Stress Pattern Analysis by Thermal Emission, was implemented to obtain full-field measurements of surface stresses during damage initiation and growth. A new micromechanical theory of the adiabatic thermoelastic effect in Iaminated fiber composites was conceived to assist the interpretation of SPATE measurements.Ph. D.
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Mehrabani, Reza Vojoudi [Verfasser]. "Reinforced Concrete Beams Subjected to Reversed Cyclic Shear / Reza Vojoudi Mehrabani". Aachen : Shaker, 2017. http://nbn-resolving.de/urn:nbn:de:101:1-201712219501.
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Li, Yantao. "Behaviour of moment-resisting multi-fastener joints subject to reversed cyclic load". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0035/MQ65502.pdf.
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Akin, Umut. "Seismic Assessment Of Reinforced Concrete Beam-to-column Connections Under Reversed Cyclic Loading". Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613123/index.pdf.
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Prior experimental research clearly reveals that the performance of reinforced concrete frame structures under earthquake loading is closely related to the behavior of beam-to-column connection regions. In order for a reinforced concrete building to have an adequate response under high lateral deformations, beam-to-column connections should be able to preserve their integrity. However, even today beam-to-column connections are assumed to be rigid or elastic, leading to an incorrect estimation of the structural response under earthquake loading. One of the basic reasons for the assumption of rigid joints is the lack of analytical models that adequately represent the seismic behavior of the connection region. In this thesis, an analytical model that realistically represents the beam-to-column connection response is developed, in the light of prior experimental data. The experimental subassemblies used in the generation of the analytical model are later modeled in OpenSees environment in order to verify the accuracy of the model. Throughout the research, utmost attention is paid for the model to be simple enough to be used practically and also to cover a wide range of beam to column connection properties.
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Dabbagh, Hooshang Civil & Environmental Engineering Faculty of Engineering UNSW. "Strength and ductility of high-strength concrete shear walls under reversed cyclic loading". Awarded by:University of New South Wales. School of Civil and Environmental Engineering, 2005. http://handle.unsw.edu.au/1959.4/27467.
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This study concerns the strength and behaviour of low-rise shear walls made from high-strength concrete under reversed cyclic loading. The response of such walls is often strongly governed by the shear effects leading to the shear induced or brittle failure. The brittle nature of high-strength concrete poses further difficulties in obtaining ductile response from shear walls. An experimental program consisting of six high-strength concrete shear walls was carried out. Specimens were tested under inplane axial load and reversed cyclic displacements with the test parameters investigated being longitudinal reinforcement ratio, transverse reinforcement ratio and axial load. Lateral loads, lateral displacements and the strains of reinforcement in edge elements and web wall were measured. The test results showed the presence of axial load has a significant effect on the strength and ductility of the shear walls. The axially loaded wall specimens exhibited a brittle behaviour regardless of reinforcement ratio whereas the specimen with no axial load had a lower strength but higher ductility. It was also found that an increase in the longitudinal reinforcement ratio gave an increase in the failure load while an increase in the transverse reinforcement ratio had no significant effect on the strength but influenced the failure mode. A non-linear finite element program based on the crack membrane model and using smeared-fixed crack approach was developed with a new aggregate interlock model incorporated into the finite element procedure. The finite element model was corroborated by experimental results of shear panels and walls. The finite element analysis of shear wall specimens indicated that while strengths can be predicted reasonably, the stiffness of edge elements has a significant effect on the deformational results for two-dimensional analyses. Therefore, to capture the deformation of walls accurately, three-dimensional finite element analyses are required. The shear wall design provisions given in the current Australian Standard and the Building Code of American Concrete Institute were compared with the experimental results. The comparison showed that the calculated strengths based on the codes are considerably conservative, specially when there exists the axial load.
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Shaback, J. Brad. "Behaviour of square HSS braces with end connections under reversed cyclic axial loading". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ65011.pdf.
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O'Loughlin, R. L. "Optimal design of organic refrigerant reverse cycle absorption air conditioning systems /". Title page, contents and abstract only, 1986. http://web4.library.adelaide.edu.au/theses/09ENS/09enso52.pdf.
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Rebehmed, Joseph. "Molecular modelling and design of inhibitors for the HIV-1 reverse transcriptase and cyclin dependent kinases". Paris 7, 2009. http://www.theses.fr/2009PA077177.
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Les techniques de modélisation moléculaire ont révélé être d'une grande aide dans l'amélioration de l'efficacité de n'importe quelle étape du processus de découverte des médicaments, et cela en diminuant les coûts d'expérimentation et en réduisant le temps. Dans ce travail, nous avons étudié le mode d'interaction de certains inhibiteurs avec deux systèmes biologiques d'intérêt pharmacologique: la transcriptase inverse du virus d'immunodéficience humaine 1 (VIH-1) et la cycline kinase dépendante 5 (CDK5). L'objectif de ce travail est de comprendre le processus d'inhibition et de fournir des informations cruciales pour la conception de nouvelles molécules inhibitrices plus efficaces. À ces fins, nous avons utilisé des approches de QSAR, d'amarrage moléculaire (docking) et des simulations de dynamique moléculaire. À partir des résultats obtenus, différentes modifications chimiques ont été proposées pour concevoir de meilleurs médicaments et leurs synthèses sont en cours. Simultanément, des calculs de chimie quantique ont été effectués pour assister la synthèse organique expérimentale des ces nouveaux composésMolecular modelling techniques showed to be of great help in increasing the efficiency of any stage of the drug discovery process by decreasing experimental costs and reducing time. In this work, we studied the interaction mode of some inhibitors with two biological Systems of pharmacological interests: The human immunodeficiency virus 1 reverse transcriptase (HIV-1 RT) and the cyclin dependant kinase 5 (CDK5) proteins. The aim of this work is to understand the inhibition process and provide crucial information for designing new and more efficient drugs molecules. For these purposes, we used QSAR, docking and molecular dynamics simulations approaches. From the obtained results, different chemical modifications were proposed to design better drugs and their syntheses are underway. Simultaneously, quantum chemistry calculations were performed to assist the experimental organic synthesis
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Sharbatdar, Mohammad-Kazem. "Concrete columns and beams reinforced with FRP bars and grids under monotonic and reversed cyclic loading". Thesis, University of Ottawa (Canada), 2003. http://hdl.handle.net/10393/29066.
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The use of fiber reinforced polymer (FRP) reinforcement is currently being explored by the construction industry as a new and innovative material. A significant force behind this consideration is the superior performance of FRP material in corrosive environments. FRP possesses high strength-to-weight ratio, favorable fatigue strength, and low relaxation characteristics when compared with steel reinforcement, offering economically and structurally sound alternative for most applications. The majority of current FRP applications have been in the area of rehabilitation and strengthening of existing structures, although some attempts have been made for application to new construction.
The research program consisted of four phases; (i) columns under eccentric monotonic loading; (ii) reinforced cylinders under concentric compression; (iii) columns under constant axial compression and lateral load reversals, and (iv) cantilever beams subjected lateral monotonic or cyclic loading. The results of tests conducted at the Structures Laboratory of the University of Ottawa indicate that CFRP reinforcement can be used effectively in new concrete members. CFRP reinforced columns subjected to eccentric loading were able to develop their expected moment capacities as governed by the crushing of concrete. All columns under cyclic loading sustained a lateral drift level exceeding 2% and 2.5% limits specified for earthquake resistant columns in the National Building Code of Canada (1995, 2005). Failure in these columns was initiated by the spalling of concrete cover, followed by the buckling of FRP bars in compression at approximately 0.45% to 0.60% compressive strain, and subsequent crushing of the core concrete. The failure of FRP bars in compression was due to instability. The stability failure of FRP bars in compression was different than that observed in steel reinforcing bars. The hysteretic relationship of flexure dominant FRP reinforced beams indicated stiffness degradation under cyclic loading due to the progressive cracking of concrete and associated softening in the member, developing approximately 3% lateral drift ratio prior to failure. This level of lateral drift may be considered to be sufficient for earthquake resistant construction. All the flexure dominant members developed their flexural capacities computed on the basis of plane-strain analysis. (Abstract shortened by UMI.)
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Abulkhair, Nesreen. "Investigating the effect of mechanical loading in a total reversed shoulder implant". Thesis, Brunel University, 2012. http://bura.brunel.ac.uk/handle/2438/7652.
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The shoulder joint is a multi-axis synovial ball and socket joint, by having a loose connection it provides a wide degree of freedom; however this means the joint lacks robustness and is prone to damage most commonly from shoulder dislocations. A rotator cuff tear causes major problems in allowing the arm to be lifted beyond a 90˚ abduction position. It is common that this insufficiency aggravates arthritis problems that may have occurred due the rotator cuff tear problem. The study focuses on investigating, describing and quantifying the implant geometric properties to evaluate the joint contact characteristics and use the outcome in redesign the implant. The investigation presents results of finite element analysis on a heavy loading condition on a Verso (reverse) shoulder implant which is validated using experimental data on the same prosthesis. The results are validated within a 5% error margin. A Verso implant is modelled using MIMICS (materialise) and imported into ABAQUS (Simulia, Providence, USA) to analyse the distribution of stress, strain and displacement across the Humerus and Scapula. Details of interaction, boundary conditions, loads and material properties are all obtained from research and applied to the model to portray realistic behaviour. The resulting stress, strain and displacement from this simulation are indicated to show the magnitude and distribution across the entire bone region. This validates the benefits of a Verso implant compared to conventional and long stemmed reverse shoulder implants, as well as provide a basis from which improved designs can be built upon and allow further accurate methods to be developed in analysing shoulder implants effectively.
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Faze, Natasha Ranjit. "Life Cycle And Economic Analysis Comparing Microbial Desalination Cell And Reverse Osmosis Technologies". The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1428934798.
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Robazza, Brook Raymond. "Out-of-plane stability of reinforced masonry shear walls under seismic loading : in-plane reversed cyclic testing". Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45238.
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Reinforced concrete block masonry shear walls (RMSWs) often constitute the principal seismic
force resisting system in masonry structures in Canada. During an earthquake, these walls
experience the combined effects of axial gravity loading and overturning moments due to inplane
lateral seismic forces. This loading precipitates out-of-plane instability when the
longitudinal reinforcement in the wall end zones is subjected to cycles of high tensile strain
followed by compression. The Canadian masonry design standard (CSA S304.1-04) [Canadian
Standard Association 2004] stipulates stringent height-to-thickness ratio limits for the seismic
design of ductile RMSWs. Experimental research and earthquake evidence have demonstrated
this failure mechanism in reinforced concrete shear walls loaded in-plane. However, similar
evidence of the mechanism occurring in RMSWs is not available. This provided motivation for
the research study described in this thesis.
The research presented here represents the second phase of a comprehensive multi-phase
research program. The first phase involved the experimental testing of full-scale reinforced
masonry (RM) column-like specimens subjected to uniaxial cyclic tension-compression loading.
The testing provided valuable insight into the out-of-plane instability as it occurs in RM. The
second phase of the research program focused primarily on the lateral reversed-cyclic
experimental testing of two full-scale, slender RMSWs with height-to-thickness ratios of 27, well
exceeding the CSA S304.2 limits. The target failure mode was an out-of-plane failure
mechanism. The results contribute unique benchmark data for the qualitative and quantitative
assessment of the factors influencing out-of-plane instability of RMSWs as well providing better
understanding of the mechanism itself. The effect of applied axial stress on out-of-plane
instability is evaluated and possible other influential design parameters are discussed.
From the results of the experimental study, it was concluded that the applied axial stress is a
critical factor in the initiation of out-of-plane instability. This factor had effects on many other
parameters, the most important of which was the development of tensile strain in the vertical
reinforcement as well as the width and distribution of cracks over the plastic hinge height. These
results indicate that the height-to-thickness ratio alone may not be an adequate factor governing
the occurrence of out-of-plane instability in RMSWs.
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Jonrinaldi, J. "Modelling of coordinating production and inventory cycles in a manufacturing supply chain involving reverse logistics". Thesis, University of Exeter, 2012. http://hdl.handle.net/10036/4046.
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In today’s global and competitive markets selling products at competitive prices, coordination of supply chain configuration, and environmental and ecological consciousness and responsibility become important issues for all companies around the world. The price of products is affected by costs, one of which is inventory cost. Inventory does not give any added value to products but must be kept in order to fulfill the customer demand in time. Therefore, this cost must be kept at the minimum level. In order to reduce the amount of inventory across a supply chain, coordination of decisions among all players in the chain is necessary. Coordination is needed not only for a two-level supply chain involving a manufacturer and its customers, but also for a complex supply chain of multiple tiers involving many players. With increasing attention being placed to environmental and ecological consciousness and responsibility, companies are keen to have a reverse supply chain where used products are collected and usable components remanufactured and reused in production to minimize negative impacts on the environment, adding further complexity to decision making across a supply chain. To deal with the above issues, this thesis proposes and develops the mathematical models and solution methods for coordinating the production inventory system in a complex manufacturing supply chain involving reverse logistics and multiple products. The supply chain consists of tier-2 suppliers for raw materials, tier-1 suppliers for parts, a manufacturer who manufactures and assembles parts into finished products, distributors, retailers and a third party who collects the used products and returns usable parts to the system. The models consider a limited contract period among all players, capacity constraints in transportation units and stochastic demand. The solution methods for solving the models are proposed based on decentralized, semi-centralized and centralized decision making processes. Numerical examples are used by adopting data from the literature to demonstrate, test, analyse and discuss the models. The results show that centralised decision making process is the best way to coordinate all players in the supply chain which minimise total cost of the supply chain as a whole. The results also show that the selection of the length of limited horizon/ contract period will be one of the main factors which will determine the type of coordination (decentralised, centralised or semi-centralised) among all players in the supply chain. We also found that the models developed can be viewed as generalised models for multi-level supply chain by examining the models using systems of different tiers from the literature. We conclude that the models are insensitive to changes of input parameters since percentage changes of the supply chain’s total cost are less than percentage changes of input parameters for the scenarios studied.
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Kaufmann, Bruno. "The Reverse Product Cycle Model Revisited: Co-produced solutions in knowledge-intensive business services". Thesis, KTH, Entreprenörskap och Innovation, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-51487.
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Services and innovation are the drivers of today’s economy, yet, there is a lack on academic literature on what matter the interactions between these two forces. On that sense, Barras, in 1986, established one of the most representative models regarding innovation within service firms. The “Reverse Product Cycle” (RPC) argue that service firms, trigged by IT advancements, would follow an opposite innovation evolution if compared to the classic manufactured view of novelty progress. Besides representing an important breakthrough on the services differentiation from the predominant industry view, it was replete of problematic that are now reinforced by the present high dynamic environment. On that present scenario, the role knowledge-intensive business services (KIBS) play is of crucial importance to innovation dissemination within a diversity of industries. It features are intrinsically related to tailored co-produced solutions to specific clients requirements that, by the case study of an ongoing KIBS shared solution development, seems to bring back the innovation pattern defended by the RPC model. The present study aims to analyze this hypothesis and revisit the RPC model through the optics of current KIBS innovation process.
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Aingaran, S. "Experimental investigation of static and cyclic behaviour of scaled railway ballast and the effect of stress reversal". Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/366814/.
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The aim of the research was to improve the fundamental understanding of mechanical behaviour of ballast and study the effect of tamping on ballast. The experiments were carried out on scaled railway ballast to eliminate the difficulties associated with testing large particle granular materials. Consideration was given to the gradation, mineralogy and shape during scaling. Particle characterisation work was carried out on scaled and full size ballast using imaging techniques to examine the validity of the use of scaled ballast. Detailed analysis of results is used to quantitatively measure the changes in shape with particle size. The results show measurable differences in particle shape between different particle size intervals. As the differences are small in magnitude, they do not invalidate the use of scaled ballast. Monotonic, cyclic experiments were carried out as part of a laboratory testing programme. Scaled ballast shows generally similar stress strain behaviour to larger granular materials. The friction angle of 40o to 50o for the confining pressure range of 15 kPa to 200 kPa falls within the range of friction angle obtained for full size ballast in the literature. The effect of changing confining pressure during train loading was examined. The results show that the settlement increases and the stiffness reduces when the confining pressure cycles. The effect of principal stress reversal during tamping was examined by an extension stage after the cyclic loading. It is shown that massive settlement occurs after the extension stage during initial cycles and settlement returns back to the pre-extension stage soon under loading. The results evidence the disruption of ballast structure and loss of stiffness due to tamping. Specimens were resin stabilised within the triaxial cell after specific stress paths had been followed. The changes in structure during a specific stress path can be studied by CT examination.
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Forster, Christopher James. "DEVELOPMENT OF AN AIR‐CYCLE ENVIRONMENTAL CONTROL SYSTEM FOR AUTOMOTIVE APPLICATIONS". DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/197.
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An air‐cycle air conditioning system, using a typical automotive turbocharger as the core of the system, was designed and tested. Effects on engine performance were kept to a minimum while providing the maximum amount of cooling possible and minimizing weight and space requirements. A test stand utilizing shop compressed air was developed to measure component performance. An unmodified automotive turbocharger was tested initially as a baseline in a Reversed‐Brayton Cycle air cooling system. Once the baseline was established, another aircycle machine, assembled from commercial turbocharger components chosen individually to optimize their performance for cooling purposes, was tested to improve the overall cycle efficiency. Finally, once the air‐cycle air conditioning system was optimized, it was tested on an engine to simulate more realistic operating conditions and performance. The shop‐air test stand experiments showed a peak dry‐air‐rated (DAR) coefficient of performance (COP) of 0.38 and a DAR cooling capacity of 0.45 tons for the baseline turbocharger, and a peak DAR COP of 0.73 and DAR cooling capacity of 1.5 tons for the optimized system with a modified turbocharger. The on‐engine testing was limited due to a thrust bearing failure in the ACM. However, the data collected at lower engine load and speed indicates a DAR COP of 0.56 and a DAR cooling capacity of 0.72 tons. On‐engine testing was planned to include operating points where the stock turbocharger was utilizing turbine‐bypass to limit boost pressure. While it wasn't possible to continue testing, it is expected that DAR COP and cooling capacity would have increased at higher engine load and speed, where turbine‐bypass operation typically occurs.
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Singh, Rajendra. "Towards Information Polycentricity Theory - Investigation of a Hospital Revenue Cycle". Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/ceprin_diss/3.
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This research takes steps towards developing a new theory of organizational information management based on the idea that information creates ordering effects in transactions and on the idea that there are multiple centers of authority in organizations. The rationale for developing this theory is the empirical observation that hospitals have great difficulty in managing information relating to transactions with patients. The research illustrates the detailed workings of an initial conceptual framework based on an action research project into the revenue cycle of a hospital. The framework facilitates a deeper understanding of how information technology can help transform information management practices in complex organizations, such as hospitals. At the same time, this research adds to the literature on Polycentricity Theory by linking its two core concepts – multiple nested centers of decision-making and context-dependent governance – with Transaction Cost Theory and information management theories to establish a new foundation for understanding the role of information technology in organizational contexts.
34
Read, Jacinda. "Narratives of transformation : feminism, femininity and the rape-revenge cycle". Thesis, University of Warwick, 1998. http://wrap.warwick.ac.uk/4338/.
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This thesis analyses the 'rape-revenge' films of the post- 1970 period. Against the tendency of existing work in this area to categorize rape-revenge as a sub-genre of horror, I argue that rape-revenge is better understood as a narrative structure which, on meeting the discourses of second-wave feminism in the 1970s, has produced an historically specific, but generically diverse cycle of films. I suggest, therefore, that the rape-revenge cycle might usefully be read as one of the key ways in which Hollywood has attempted to make sense of feminism and the changing shape of heterosexual femininity in the post-1970 period. Using a model of cultural analysis influenced by Gramsci's theory of hegemony, I argue that it is in the struggle between the feminist stories the rape-revenge structure attempts to tell and the feminine stories embedded in the genres over which it has been mapped that common-sense understandings of feminism are produced. Initial consideration is given to the ideological effects of various generic deployments of the rape-revenge structure in the pre-1970 period. Subsequent chapters explore the ways in which post-1970 deployments of the structure negotiate and rework the 'mass cultural fictions of femininity' inscribed in the genres over which they have been mapped, and the understandings of feminism these negotiations have produced. The ways in which extra-textual material such as reviews contribute to the construction of these understandings is also explored. Additional consideration is given to the increasing influence of post-modern aesthetics on Hollywood film, the emergence of the New Right during the 1980s and the characterization of this period as one of post-feminism or backlash. In identifying the rape-revenge cycle as one of the key sites through which the meanings of feminism are constructed and negotiated, I suggest that the most politically expedient form feminist film theory can take today is not one which attempts to separate feminist film from mainstream film, the political from the popular, but one which attempts to theorize the relationship between feminism and film, the political and the popular.
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Sharma, Manu. "Reverse Logistics and Environmental Considerations in Equipment Leasing and Asset Management". Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4869.
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Reverse Logistics and Environmental Considerations in Equipment Leasing and Asset Management
Manu Sharma
151 Pages
Directed by Dr. Jane C. Ammons
Today many business enterprises employ capital assets in the form of electronic equipment (e.g., personal computers, workstations and peripherals) in large quantities. As a result of rapid technological progress, these products have a very short life cycle, typically not much more than three or four years. Unfortunately, the disposal of electronic equipment (which contains hazardous materials) presents an environmental problem. In the face of rapid equipment changes, current tax laws and disposal challenges, leasing or procurement contracts with take-back considerations are attractive. For a large electronic equipment leasing company, optimal management of assets supported by good logistics decisions is crucial and may provide a significant competitive advantage. The leasing company tries to maximize operating profits through key decisions associated with the length of leases, efficient utilization of logistics facilities for material flow to and from customer sites, and equipment reuse, refurbishment and disposal actions.
In this research, a mixed integer linear programming (MILP) model is developed to facilitate better decisions from the perspective of an electronic equipment leasing company. The model reduces to a linear program (LP) under certain cost assumptions. All computational results are based on the LP version of the model. A case study with representative industry data validates the approach and demonstrates the utility of the model in answering key research questions. Next, important problem uncertainties are identified and prioritized. The effects of these key uncertainties on optimal lease length and product flow decisions are examined in detail via an extended case study. It is also shown how the leasing company can make near-robust leasing decisions in the face of these uncertainties.
The computational research results also have implications for policy formulation on electronic waste. The important insights include an understanding of the potential impacts and expected effectiveness of alternative environmental legislation in different geographic areas, and the imposition of negative externalities on other policy realms as a result of this non-uniform approach. Therefore, this research contributes new models and understanding to the intersection of the fields of reverse logistics and equipment replacement, and provides valuable insights to both business asset managers and environmental policy makers.
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Salas, Claudio D. "Ádám's Conjecture and Arc Reversal Problems". CSUSB ScholarWorks, 2016. https://scholarworks.lib.csusb.edu/etd/337.
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A. Ádám conjectured that for any non-acyclic digraph D, there exists an arc whose reversal reduces the total number of cycles in D. In this thesis we characterize and identify structure common to all digraphs for which Ádám's conjecture holds. We investigate quasi-acyclic digraphs and verify that Ádám's conjecture holds for such digraphs. We develop the notions of arc-cycle transversals and reversal sets to classify and quantify this structure. It is known that Ádám's conjecture does not hold for certain infinite families of digraphs. We provide constructions for such counterexamples to Ádám's conjecture. Finally, we address a conjecture of Reid [Rei84] that Ádám's conjecture is true for tournaments that are 3-arc-connected but not 4-arc-connected.
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Santos, Marcus Vinicius Rezende dos. "O efeito do atraso em movimentos reversos do cotovelos : comparação entre sujeitos saudaveis e portadores da doença de Parkinson". [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314247.
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Orientador: Gil Lucio AlmeidaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-06T21:23:30Z (GMT). No. of bitstreams: 1 Santos_MarcusViniciusRezendedos_M.pdf: 2514721 bytes, checksum: a7b1ab66caadf0d4fb9a3367038033d5 (MD5) Previous issue date: 2005
Resumo: Neste trabalho, foram investigados efeitos de condições especiais como o envelhecimento e a Doença de Parkinson no controle de movimentos reversos do cotovelo, realizados com um atraso variável entre a ida (Ml) e a volta (M2) do mesmo. Outro objetivo foi verificar se o ciclo de alongamento-encurtamento (CAE) age como potencializador da contração muscular nessa população. Foram recrutados 12 voluntários, sendo seis sujeitos saudáveis (três homens e três mulheres) com idades entre 51 e 71 anos (Média = 62.33 e DP = 8.95) e seis portadores da doença de Parkinson (três homens e três mulheres) com idades entre 59 e 77 anos (Média = 68.66 e DP = 7.47). Eles realizaram movimentos uni-articulares rápidos de reversão com o cotovelo, que se movia em direção à um alvo (Ml) e depois retomava à posição inicial (M2). Esses movimentos foram realizados em três diferentes distâncias (20°, 40° e 60°) e entre os dois componentes (Ml e M2) foi realizado um atraso variável (Os, 0.2s, 0.5s e ls). O deslocamento angular do cotovelo foi registrado por um sistema óptico de análise do movimento (OPTOTRAK@ 3020) e a atividade elétrica dos músculos braquiorradial (BRR) e cabeça lateral do tríceps braquial (TR) foi registrada através de um eletromiógrafo EMG DelSYS (modelo DE2.2L) com eletrodos de superficie. O envelhecimento saudável não influenciou os padrões EMG utilizados por esses indivíduos para ativar os músculos agonista e antagonista na realização de movimentos uni-articulares com reversão com diferentes atrasos. A velocidade dos movimentos executados por esses indivíduos foi mais baixa devido ao uso de um padrão semelhante aos sujeitos jovens, porém com uma menor quantidade de ativação. Os parkinsonianos moveram mais lentamente que os idosos saudáveis e indivíduos saudáveis devido a algumas alterações na modulação da atividade EMG. Apesar de apresentarem a manutenção do padrão trifásico, a atividade elétrica dos músculos ocorreu na forma de vários bursts altemantes durante toda a realização da tarefa, o que provocou uma redução na quantidade de ativida elétrica dos músculos. Os parkinsonianos não reduziram a magnitude do segundo burst agoninos movimentos sem atraso, o que trouxe uma dificuldade maior para reverter os moviment< Por fim, notou-se que os indivíduos portadores da doença de Parkinson relaxavam menos a SI musculatura e iniciavam o retomo à posição inicial necessitando de uma atividade maior do 1 para gerar uma velocidade igual à dos indivíduos saudáveis, o que não aconteceu. ( movimentos que reverteram sem atraso apresentaram um valor maior da velocidade movimento de retomo à posição inicial, mesmo nos portadores da doença de Parkinso confirmando a ação potencializadora do ciclo de alongamento-encurtamento (CAE) sobre músculo tríceps. Isso suporta a influência, tanto dos reflexos (gerados pelo estiramento muscula quanto da energia potencial armazenada pelo músculo e tendão, que têm suas origens na fa: excêntrica do CAE e são liberados no movimento de volta (fase concêntrica). Palavras-chave: Movimentos reversos, doença de Parkinson, ciclo de alongamento encurtamento, eletromiografia e cinemática
Abstract: Within this study were investigated the effects of special conditions like aging and the Parkinson's disease on the control ofreversal movements ofthe elbow joint performed with a variable delay between the two components (Ml and M2) ofreversal. Another aim was to verify if the stretch-shortening cycle exerts his potentiating effects on muscular contraction in this population. To perform these observations, 12 volunteers were recruited. Six of them (3 males and 3 females) were normal at their neurological assessment and were between 51 and 71 years of age (Mean = 62.33 e S.D.= 8.95), and the other six (3 males and 3 females) had been diagnosised with Parkinson disease and were between 59 and 77 years old (Mean = 68.66 e S.D. = 7.47). They executed fast single-joint movements with a reversal, moving towards a target (Ml) and getting back to the initial position (M2). These movements were accomplished in three different distances (20°, 40° and 60°) and between the two components ofreversal (Ml e M2) there were variable delays (Os, 0.2s, 0.5s eIs). The elbow angle was recorded using a optoelectric system of motion analysis (OPTOTRAK@ 3020) and the electrical activity of braquioradialis (BRR) and lateral head of triceps brachi (TR) muscles were recorded by a electromyograph EMG DelSYS (model DE2.2L) with surface electrodes placed over the muscles bellies. The aging did not affect the EMG patterns used by these persons in activating the agonist and antagonist muscles to accomplish single-joint movements with a delay between the movements toward the target and the return to the initial position. The velocity of movements executed by the elder1y volunteers was lower due to the fact that the same strategy applied to young hea1thy persons was used, however with less EMG activity. The volunteers with Parkinson's disease moved slower than the heaIthy elderly and young subjects due to aIterations in the modulation of EMG activity. Altough they kept the triphasic pattern, the EMG showed multiple bursts that aItemated during the task accomplishmen~ which decreased the amount of ellectricaI activity. Besides, they did not reduce the magnitude of second agonist burst in the reversaI movements without delay, what made the reversion harder. FinaIly, it was noticed that the parkinsonians showed less relaxation of his muscles during the intervaI between TI-T4, and started the return movement needing more TR activity to produce the same velocity, when compared to heaIthy persons, which was not the case. Those movements that reverted with no delay showed higher values concerning the second peak ofvelocity, even within the volunteers with Parkinson disease, sustaining the potentianting action of SSC over the triceps muscle. This effect comes from the influence of reflexes (generated by the muscle stretching), as well as the storage of elastic energy in the muscle and tendon in the eccentric phase of SSC, which are released at the movement of returning (concentric phase)
Mestrado
Fisiologia
Mestre em Biologia Funcional e Molecular
38
Varma, Sreejith Jayasree. "Mimicking C-C bond forming reactions of core metabolism". Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAF038/document.
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Toutes les formes de vie assemblent et désassemblent continuellement des composés chimiques via un processus de consommation d'énergie appelé métabolisme. Le métabolisme est généralement modélisé en chimie et biologie par un cycle. Ce modèle dynamique traduit la transformation de composés de base en une cascade de produits appelés métabolites. Celui-ci est comparable à un ouragan à l’échelle moléculaire. De manière analogique et imagée un cyclone est constitué de deux éléments, l'air et l'eau, et transforme l’environnement qui l’entoure par un processus endothermique (consommateur d’énergie). Traditionnellement, la recherche chimique sur les origines de la vie est concentrée principalement sur la synthèse de composés chimiques sans suffisamment apprécier leur place dans la plus grande organisation biochimique de la vie. La vie construit toutes ses molécules à partir du dioxyde de carbone, pourtant elle manque étonnamment d'innovation à cet égard. Malgré presque 4 milliards d'années d'évolution, les organismes autotrophes utilisent seulement six voies différentes pour construire leurs molécules à partir du CO2. Parmi elles, deux voies – la voie de l’acétyle CoA (aussi appelée voie Wood-Ljungdahl) et le cycle du rTCA (également appelé le cycle de Krebs inverse) - sont considérées comme primitives, et contiennent les cinq molécules servant de précurseurs chimiques universels pour toute la biochimie. Comment et pourquoi les voies de l’acétyle CoA et du rTCA sont-elles apparues? Pour répondre à cette question, une recherche systématique a été effectuée afin de trouver des catalyseurs chimiques non-enzymatiques ou des minéraux simples, ainsi que des réactifs pouvant promouvoir les réactions d'anabolisme principal, particulièrement la voie de l’Acétyle CoA et le cycle de rTCA. A l’origine, pour créer les molécules organiques complexes comme les enzymes il a fallu que des molécules plus simples avec un moins grand nombre de carbone se forme sur terre et cela à partir du CO2. On peut donc supposer que les premiers produits à plusieurs carbones sont issus de synthèse totalement inorganique comme celles développer dans notre laboratoire, plutôt que d’une évolution chimique et organométallique simultanée, c’est-à-dire une interaction efficace entre une molécule carbonée et un ou plusieurs métaux à l’instar de certains enzymes. Après avoir trouvé autant de façons possible de promouvoir individuellement chaque étapes des cycles catalytiques étudiés, seules les conditions réactionnelles mutuellement compatibles (à savoir des conditions permettant de produire l’ensemble des métabolites dans le bon ordre) ont été retenuAll life forms continuously build up and break down its constituent chemical building blocks, through an energy consuming process called metabolism. Just like a hurricane’s dynamic patterns and its building blocks (air and water) as being equally fundamental to its nature, so too should metabolism’s dynamic chemical patterns and chemical building blocks be viewed as equally characteristic. Traditionally, much chemical research on the origins of life is overly focused on the synthesis of chemical building blocks without sufficiently appreciating their place in life’s larger biochemical self-organization. Life ultimately builds all of its molecules from carbon dioxide, yet it is surprisingly lacking in innovation in this respect. Despite nearly 4 billion years of evolution, autotrophic organisms use only six pathways to build their molecules from CO2. Two of these pathways – the acetyl CoA pathway (also known as the Wood-Ljungdahl pathway) and rTCA cycle (also known as the reverse Krebs cycle) - are thought to be ancestral, with just five molecules within them serving as the universal chemical precursors for all of biochemistry. How and why did these pathways get their start? To answer this question, a systematic search was designed to find simple, non-enzymatic chemical or mineral catalysts and reagents, that can promote the reactions of core anabolism, particularly the acetyl CoA pathway and the rTCA cycle. After finding as many ways as possible to promote each reaction, they could be narrowed down to mutually compatible conditions where many reactions can occur in sequence. The more of core anabolism that can be achieved under a single set of purely chemical conditions, the more likely it is to have constituted early prebiotic chemistry rather than a later product of chemical and biological evolution
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Gonzalez, Cardozo Carlos Aurelio. "Manufatura digital aplicada no contexto de engenharia reversa : estudo de caso : protótipo virtual do avião Blériot". [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265311.
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Orientador: João Maurício RosárioDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
Made available in DSpace on 2018-08-20T17:16:06Z (GMT). No. of bitstreams: 1 GonzalezCardozo_CarlosAurelio_M.pdf: 3291710 bytes, checksum: 44b69cb0622c9a8dd792e7d9b3e4cee9 (MD5) Previous issue date: 2012
Resumo: A Manufatura Digital integra o projeto do produto ao planejamento dos processos de manufatura e de suporte ao produto. Produtos, processos e recursos são modelados a partir de dados reais, em uma fábrica virtual. O funcionamento desta fábrica virtual é testado até sua validação e os resultados são aplicados na fábrica real. É uma importante alternativa com potencial para transformar os negócios, tornando-os mais competitivos, graças aos diversos benefícios conseguidos com a Manufatura Digital, tais como redução dos ciclos de desenvolvimento do produto e dos custos de manufatura, aceleração de resposta ao mercado, aumento da qualidade do produto, melhoras na disseminação do conhecimento do produto. O objetivo deste estudo é descrever a aplicação da Manufatura Digital no Contexto de Engenharia Reversa através de um estudo de caso de um Projeto Colaborativo Internacional que resultou no Protótipo Virtual de um avião Blériot XI e fabricação de uma réplica deste avião, com o objetivo de validar a implantação da Manufatura Digital em um ambiente educacional
Abstract: The Digital Manufacturing integrates product design to manufacturing process planning and product support. Products, processes and resources are modeled from real data in a virtual factory. The operation of the virtual factory is tested to its validation and the results are applied to actual plant. It is an important alternative with the potential to transform businesses, making them more competitive, thanks to the many benefits achieved through Digital Manufacturing, such as reducing product development cycles and manufacturing cost, rapid response to market, increased product quality improvements in the dissemination of product knowledge. The aim of this study is to describe the application of Digital Manufacturing in the Context of Reverse Engineering through a case study an International Collaborative Project which resulted in the Virtual Prototype of an airplane Blériot XI and manufacture of a replica of this plane, with the aim of validating the deployment of Digital Manufacturing in an educational environment
Mestrado
Mecanica dos Sólidos e Projeto Mecanico
Mestre em Engenharia Mecânica
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Elliott, Brian P. "“Messengers of Justice and of Wrath”: The Captivity-Revenge Cycle in the American Frontier Romance". Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1303933331.
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Oliveira, Ariane Braga. "Avaliação do ciclo de vida de cenários de logística reversa de embalagens de agrotóxicos no Brasil /". Bauru, 2019. http://hdl.handle.net/11449/183494.
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Orientador: Sandro Donnini ManciniCoorientador: Bruno Fernando Gianelli
Banca: Diogo Aparecido Lopes Silva
Banca: Gerson Araújo de Medeiros
Banca: Ricardo Gabbay de Souza
Banca: Michel Xocaira Paes
Resumo: Neste trabalho foi realizada a Avaliação do Ciclo de Vida (ACV) do processo de logística reversa da destinação de embalagens vazias de agrotóxicos empregado atualmente no Brasil. Esse procedimento apresenta um fluxo que se inicia na entrega das embalagens, após o uso, em postos de recebimento que encaminham a unidade maiores, denominadas centrais que, por sua vez, remetem os invólucros a incineradoras e recicladoras associadas ao órgão que administra o processo. Para avaliar esse procedimento, inicialmente, foi realizada uma ACV da fronteira final do sistema. Para tal foram utilizados dados de quantidade de embalagens destinadas, por tipo, e quantidade de viagens realizadas entre centrais e destinadoras, nos anos de 2014, 2015, 2016 e 2017 de quatro unidades de recebimento, localizadas nas cidades de: Capão do Leão/RS, Ituverava/SP, Piedade/SP e Piracicaba/SP. O método utilizado foi o Midpoint (H)/World ReCiPe H/H (2016). Nesse primeiro momento foram simulados o cenário atual e outros cenários com tratamentos diferentes dispensados às embalagens. Os resultados mostraram que as distâncias percorridas entre centrais e destinadoras prejudicam substancialmente o objetivo inicial do processo de redução de impactos ambientais. Um cenário em que são utilizadas recicladoras e incineradoras mais próximas às centrais foi capaz de reduzir os impactos ambientais em todas as categorias estudadas, para todos os anos e unidades de recebimento, atingindo, por exemplo, na central de Capão do ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In this thesis it was carried out the Life Cycle Assessment (LCA) of the reverse logistics processes for the destination of empty agrochemical containers currently employed in Brazil. This procedure was created to reduce environmental damager and the process flow starts from the delivery of packages, after use, at the receiving stations that send them to larger units, called plants. In turn, they send the casings to the incinerators and recyclers associated to the body that administers the process. In order to evaluate this procedure, initially a LCA of the final frontier of the system was performed. For this purpose, we used data on the number of packages destined, by type and number of trips made between central and destination, in 2014, 2015, 2016 and 2017 of four reception units located in the cities of: Capão do Leão / RS, Ituverava / SP, Piedade / SP and Piracicaba / SP. The method used was Midpoint (H) / World ReCiPe H / H (2016). In this first moment the current scenario and other scenarios with different treatments to the packages were simulated. The results showed that the distances traveled between centrals and destinantions substantially undermine the initial objective of the process of reducing environmental impacts. A scenario with recyclers and incinerators closer to the plants, was able to reduce environmental impacts in all categories studied, considering all the years and receiving units, reaching, for example, the Capão do Leão plant - the farthest one amon... (Complete abstract click electronic access below)
Doutor
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Luo, Lingai. "Etude thermodynamique et thermique de machine à cycle inverse à adsorption". Vandoeuvre-les-Nancy, INPL, 1991. http://docnum.univ-lorraine.fr/public/INPL_T_1991_LUO_L.pdf.
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L'étude thermodynamique, thermique et expérimentale de la machine inverse à adsorption a été réalisée afin d'examiner les couples et les modèles théoriques en vue de l'optimisation des machines à froid par : 1) une étude thermodynamique basée sur une synthèse d'une soixantaine de travaux de littérature pour le choix du couple en vue d'utilisations diverses ; 2) une étude théorique précise de modélisation du COP reposant sur le modèle de DUBININ-RADUSHKEVICH pour la comparaison avec les différents modèles de la littérature ; 3) une étude de trois modèles transitoires de générateur : un modèle global, un modèle à partir d'une discrétisation radiale du générateur cylindrique et un modèle à partir du comportement d'un grain cylindrique, conduisant à une meilleure représentation des évolutions de température, de masse cyclée ainsi que de la distribution radiale de température pendant la phase d'adsorption et la phase de désorption ; 4) une étude expérimentale sur la maquette réalisée en laboratoire avec le couple charbon actif ac35/3-méthanol ou éthanol, débouchant sur une connaissance des températures, pressions et de la masse adsorbée au cours du cycle ; 5) une comparaison des modèles théoriques et des résultats expérimentaux permettant la discussion de leurs validités
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Linke, Julia M., Dmitry Yu Borin y Stefan Odenbach. "First-order reversal curve analysis of magnetoactive elastomers". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-224278.
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The first magnetization loop and the first stress–strain cycle of magnetoactive elastomers (MAEs) in a magnetic field differ considerably from the following loops and cycles, possibly due to the internal restructuring of the magnetic filler particles and the matrix polymer chains. In the present study, the irreversible magnetization processes during the first magnetization of MAEs with different filler compositions and tensile moduli of the matrix are studied by first-order reversal curve (FORC) measurements. For MAEs with mixed magnetic NdFeB/Fe fillers the FORC distributions and magnetization distributions of the first major loop reveal a complex irreversible magnetization behavior at interaction fields Hu < −50 kA m−1 due to the magnetostatic coupling between the magnetically hard NdFeB and the magnetically soft Fe particles. This coupling is enhanced either if the interparticle distance is reduced by particle motion and restructuring or by an increase in the particle densities. If the stiffness of the matrix is increased, the structuring and thus the interparticle interactions are suppressed and the magnetization reversal is dominated by domain processes in the NdFeB particles at high coercive fields of Hc > 600 kA m−1.
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Linke, Julia M., Dmitry Yu Borin y Stefan Odenbach. "First-order reversal curve analysis of magnetoactive elastomers". Royal Society of Chemistry, 2016. https://tud.qucosa.de/id/qucosa%3A30308.
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The first magnetization loop and the first stress–strain cycle of magnetoactive elastomers (MAEs) in a magnetic field differ considerably from the following loops and cycles, possibly due to the internal restructuring of the magnetic filler particles and the matrix polymer chains. In the present study, the irreversible magnetization processes during the first magnetization of MAEs with different filler compositions and tensile moduli of the matrix are studied by first-order reversal curve (FORC) measurements. For MAEs with mixed magnetic NdFeB/Fe fillers the FORC distributions and magnetization distributions of the first major loop reveal a complex irreversible magnetization behavior at interaction fields Hu < −50 kA m−1 due to the magnetostatic coupling between the magnetically hard NdFeB and the magnetically soft Fe particles. This coupling is enhanced either if the interparticle distance is reduced by particle motion and restructuring or by an increase in the particle densities. If the stiffness of the matrix is increased, the structuring and thus the interparticle interactions are suppressed and the magnetization reversal is dominated by domain processes in the NdFeB particles at high coercive fields of Hc > 600 kA m−1.
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Monteiro, Marta Emília Rodrigues. "A Panel Data Econometric Study of Corporate Tax Revenue in European Union: Stuctural, Cyclical Business and Institutional Determinants". Dissertação, Faculdade de Economia da Universidade do Porto, 2010. http://hdl.handle.net/10216/57369.
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Monteiro, Marta Emília Rodrigues. "A Panel Data Econometric Study of Corporate Tax Revenue in European Union: Stuctural, Cyclical Business and Institutional Determinants". Master's thesis, Faculdade de Economia da Universidade do Porto, 2010. http://hdl.handle.net/10216/57369.
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McMillan, Chloé. "Long-term effects of base cation fertilization on nutrient cycling and species composition of a sugar maple stand in southern Québec: application of the Rb/K reverse tracer". Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=123161.
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To improve the understanding of the long-term effect of forest potassium (K)-fertilization, I revived a 23-year-old base cation fertilization experiment in a sugar maple stand in southern Quebec (45°59.6'N 73°59.9'W). My main objectives were to determine (i) the long-term percent of K derived from fertilizer in the soil-plant system using the rubidium (Rb)/K reverse tracer method, (ii) if fertilization had altered the diversity of the understory plant community, and (iii) if there was still an effect on the growth and nutrient status of the sugar maple trees. In 1988, six 40 m × 40 m plots were delineated in a sugar maple stand. In June 1989, three of these plots received 500, 250, and 250 kg•ha-1 of K2SO4, CaMg(CO3)2, and CaCO3, respectively as fine particulate matter, and the other three were left as control. Mid-canopy leaves of sugar maple trees were sampled annually in August from 1988 to 1991 and 2011 to 2012. In 2012, understory species were surveyed using the Braun-Blanquet method and ten of the most abundant and ubiquitous species were sampled for leaf chemistry. Leaves of both understory and canopy sugar maple trees were digested for nutrient concentrations using trace metal grade HNO3. In 2012, two soil pits were dug in each plot and individual horizons were sampled. Soil was extracted with 1 M NH4Cl. K, Ca, Mg, and Rb concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS) for both digested and extracted samples. Growth of sugar maple trees was assessed using tree cores taken in 2012. Fertilization increased sugar maple leaf K two years following fertilization, but the effect was no longer detectable in 2011/2012. Only Ca and Mg showed increased concentrations in the leaves the fall of the year of fertilization. The percent of leaf K derived from fertilizer in 2011/12 is nearly what it was in the fall of 1989, two months after fertilization. There was no significant difference between control and fertilized plots in the concentration of K in the sapwood of the sugar maple trees, but there was 27 ± 2 % of K derived from fertilizer in the wood in 2012. There was no difference in relative growth of sugar maple, or understory vegetation diversity or species richness in fertilized plots. Nutrient analysis of understory vegetation showed no differences in concentrations of leaf K between treatments, but percent K from fertilizers amounted to over 25 % in several species. There was no effect of treatment on soil chemistry but there was a large proportion of the original fertilizer recovered in the soil profile. The total amount of K from fertilizer held in the soil-plant system was 54 kg•ha-1 or 24 % of the original 225 kg•ha-1 of fertilizer K applied. Overall, these results suggest: (i) a short-term improvement of K status following fertilization, (ii) efficient recycling of K fertilizer in the soil-plant system of maple forests, and (iii) no obvious long-term change in understory species composition following forest fertilization.Pour améliorer notre compréhension de l'effet de la fertilisation en potassium (K) des forêts à long terme, nous avons remis en fonction une expérience de 23 ans de fertilisation en cations basiques dans un peuplement d'érable à sucre dans le sud du Québec (45°59.6'N 73°59.9'W). Nos objectifs étaient de déterminer (i) le pourcentage de potassium (K) provenant d'engrais dans le système sol-plante 23 ans après la fertilisation en utilisant méthode de traçage inverse du rubidium (Rb) / K, (ii) si la fertilisation a modifié la biodiversité de la communauté végétale des strates arbustives et herbacées, et (iii) s'il y avait encore un effet sur la croissance et l'état nutritionnel des érables à sucre.En 1988, six 40 x 40 m parcelles ont été délimitées dans un peuplement d'érable à sucre. En juin 1989, trois de ces parcelles ont reçu 500, 250 et 250 kg•ha- 1 de K2SO4, CaMg(CO3)2 et CaCO3, respectivement, sous forme de particules fines, et les trois autres parcelles n'ont pas été fertilisées (contrôle). Les feuilles en périphérie de la couronne d'érables à sucre ont été échantillonnées annuellement en août de 1988 à 1991 et 2011 à 2012. En 2012, les espèces du sous-étage ont été échantillonnés selon la méthode de Braun-Blanquet et dix espèces les plus communes ont été analysées pour la chimie des feuilles (digestion humide au HNO3). En 2012, deux pédons ont été creusés dans chaque parcelle et les horizons ont été échantillonnés jusqu'à une profondeur de 70 cm. Les sols ont été extraits au NH4Cl (1 M). Les concentrations de Rb, K, Ca, et Mg dans les feuilles et les sols ont été déterminées par spectrométrie de masse à plasma inductif (ICP-MS). La croissance des érables à sucre a été évaluée en utilisant des carottes d'arbres récoltées en 2012.La fertilisation a augmenté le K des feuilles d'érable à sucre deux ans après la fertilisation, mais l'effet n'était plus détectable en 2011/ 2012. Les concentrations en Ca et Mg ont augmenté à l'automne de l'année de la fertilisation. Le pourcentage du K foliaire provenant des engrais en 2011/12 est à peu près ce qu'il était à l'automne 1989. La fertilisation n'a pas augmenté la concentration de K de l'aubier des arbres d'érable à sucre, mais 27 ± 2% du K provenait des engrais en 2012. La croissance relative de l'érable à sucre, et la diversité et la richesse en espèces de la végétation du sous-étage dans les parcelles fertilisées n'ont pas été affectées par la fertilisation. L'analyse des éléments nutritifs de la végétation du sous-étage n'a montré aucune différence dans les concentrations en K des feuilles entre les traitements, mais le pourcentage en K dérivé des engrais s'élevaient à plus de 25% chez plusieurs espèces. Il n'y avait aucun effet du traitement sur la chimie du sol, mais il y avait une grande proportion de l'engrais récupéré dans le profil du sol. La masse totale de K dérivé des engrais dans le système sol-plante était de 54 kg•ha-1 ou 24 % des 225 kg•ha-1 d'engrais K appliqué. Ces résultats suggèrent: (i) une amélioration à court terme de la nutrition en K suivant la fertilisation, (ii) un recyclage efficace des engrais en K dans le système sol-plante de cette érablière, et (iii) aucun changement évident à long terme de la composition en espèces du sous-étage suivant la fertilisation du peuplement.
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Lima, Carla Andreia Baggetti Ferraz de. "Excreção cervicovaginal do vírus da imunodeficiência humana (HIV) ao longo do ciclo menstrual em mulheres soropositivas acompanhadas em serviço especializado de São Paulo". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/5/5134/tde-16022009-160328/.
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A via sexual é a principal forma de transmissão inter-humana da infecção pelo vírus da imunodeficiência humana (HIV). Com o incremento do número de mulheres infectadas por esse agente retroviral, o estudo de particularidades da biologia do vírus no trato genital feminino adquiriu maior importância. Com o objetivo de avaliar a excreção genital do HIV ao longo do ciclo menstrual, coletaram-se, nas diversas fases de dois ciclos, lavados cervicovaginais de 17 mulheres soropositivas para essa infecção e acompanhadas em serviço ambulatorial especializado de São Paulo. O RNA viral livre foi quantificado por RT-PCR e o DNA proviral por PCR em tempo real, empregando sistema TaqMan. Avaliou-se ainda a carga viral plasmática de HIV, o número de células CD4+ periféricas e presença de co-infecção genital. Detectou-se excreção de RNA-HIV e de DNA proviral, respectivamente, em 18,8% e 31,3% das pacientes. Todas as pacientes que apresentaram excreção de RNA viral também exibiram a de DNA proviral, incluindo paciente com viremia de HIV indetectável. Não houve variação significativa da excreção genital do vírus durante o ciclo menstrual. Em 6 dessas pacientes, que apresentaram co-infecção genital previamente à admissão no estudo, avaliou-se também a excreção genital de HIV quando da co-infecção. Em 2 casos, a excreção genital do DNA-HIV foi superior na vigência de co-infecção causada por Streptococcus sp e Ureaplasma. Não se observou excreção de RNA viral livre nas pacientes co-infectadas. Os resultados obtidos podem contribuir para o entendimento do potencial de transmissibilidade sexual da infecção por HIV e reiteram a necessidade de adesão às práticas de sexo protegido para evitar sua transmissão inter-humanaThe sexual route is the main means of transmission of the human immunodeficiency virus (HIV). With the increasing numbers of HIV-infected women, the investigation of particular biological features of HIV infection in the genital tract has become more important. To evaluate HIV genital shedding during the menstrual cycle, we collected cervicovaginal lavages (CVL) from 17 women, assisted at an HIV outpatient clinic in São Paulo, in different hormonal phases during 2 cycles. HIV-RNA and proviral DNA shedding were quantified using RT-PCR and a TaqMan real-time PCR assay, respectively. In addition, patients were screened for genital coinfections and had their HIV plasma viral loads and CD4+ cell counts assessed. Cell-free HIV-RNA and proviral DNA shedding were found in 18.8% and 31.3% of women. All patients who shed HIV-RNA were also shown to present detectable proviral DNA in their CVL, including one woman with undetectable HIV plasma viral load. No significant difference in viral shedding was seen among menstrual cycle phases. Six patients from the cohort, who exhibited genital coinfections previous to admission to the study, had their HIV genital shedding compared at time of coinfection and after its resolution. In two of them proviral DNA shedding was higher at the time of coinfection, caused by Streptococcus sp and Ureaplasma. No cell-free HIV-RNA shedding was detected in coinfected patients. Our results may contribute to the understanding of HIV sexual infectivity from women and emphasize the need for adherence to protected sexual practices in order to avoid viral transmission.
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Daza, Yolanda Andreina. "Closing a Synthetic Carbon Cycle: Carbon Dioxide Conversion to Carbon Monoxide for Liquid Fuels Synthesis". Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6079.
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CO2 global emissions exceed 30 Giga tonnes (Gt) per year, and the high atmospheric concentrations are detrimental to the environment. In spite of efforts to decrease emissions by sequestration (carbon capture and storage) and repurposing (use in fine chemicals synthesis and oil extraction), more than 98% of CO2 generated is released to the atmosphere. With emissions expected to increase, transforming CO2 to chemicals of high demand could be an alternative to decrease its atmospheric concentration. Transportation fuels represent 26% of the global energy consumption, making it an ideal end product that could match the scale of CO2 generation. The long-term goal of the study is to transform CO2 to liquid fuels closing a synthetic carbon cycle.
Synthetic fuels, such as diesel and gasoline, can be produced from syngas (a combination of CO and H2) by Fischer Tropsch synthesis or methanol synthesis, respectively. Methanol can be turned into gasoline by MTO technologies. Technologies to make renewable hydrogen are already in existence, but CO is almost exclusively generated from methane. Due to the high stability of the CO2 molecule, its transformation is very energy intensive. Therefore, the current challenge is developing technologies for the conversion of CO2 to CO with a low energy requirement.
The work in this dissertation describes the development of a recyclable, isothermal, low-temperature process for the conversion of CO2 to CO with high selectivity, called Reverse Water Gas Shift Chemical Looping (RWGS-CL). In this process, H2 is used to generate oxygen vacancies in a metal oxide bed. These vacancies then can be re-filled by one O atom from CO2, producing CO. Perovskites (ABO3) were used as the oxide material due to their high oxygen mobility and stability. They were synthesized by the Pechini sol-gel synthesis, and characterized with X-ray diffraction and surface area measurements. Mass spectrometry was used to evaluate the reducibility and re-oxidation abilities of the materials with temperature-programmed reduction and oxidation experiments. Cycles of RWGS-CL were performed in a packed bed reactor to study CO production rates.
Different metal compositions on the A and B site of the oxide were tested. In all the studies, La and Sr were used on the A site because their combination is known to enhance oxygen vacancies formation and CO2 adsorption on the perovskites. The RWGS-CL was first demonstrated in a non-isothermal process at 500 °C for the H2-reduction and 850 °C for the CO2 conversion on a Co-based perovskite. This perovskite was too unstable for the H2 treatment. Addition of Fe to the perovskite enhanced its stability, and allowed for an isothermal and recyclable process at 550 °C with high selectivity towards CO. In an effort to decrease the operating temperature, Cu was incorporated to the structure. It was found that Cu addition inhibited CO formation and formed very unstable oxide materials.
Preliminary studies show that application of this technology has the potential to significantly reduce CO2 emissions from captured flue gases (i.e. from power plants) or from concentrated CO2 (adsorbed from the atmosphere), while generating a high value chemical. This technology also has possible applications in space explorations, especially in environments like Mars atmosphere, which has high concentrations of atmospheric carbon dioxide.
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Noubli, Halima. "Développement d’un nouveau thermo-transformateur à absorption-démixtion : optimisation conjointe du cycle et du mélange de travail". Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL089N/document.
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Ce travail porte sur l’étude d’un nouveau type de thermo-transformateur à absorption-démixtion (TTAD) utilisant un mélange présentant une lacune de miscibilité à basse température. Dans ce cycle, l’opération de séparation, est effectuée par décantation gravitaire par simple refroidissement du mélange. La séparation est ainsi énergétiquement gratuite et permet d’atteindre des rendements thermiques plus élevés que ceux des pompes à chaleur à absorption classiques dans lesquelles la séparation s’effectue par distillation.Afin de trouver des mélanges de travail pour atteindre un saut thermique de 50°C, un outil de simulation numérique a été développé pour évaluer les performances des TTAD en fonction des conditions opératoires (rapport d’alimentation et nombre d’étages de la colonne de rectification inverse) et des caractéristiques des composés du mélange de travail (Cp, Lv, paramètres caractéristiques des équilibres liquide-liquide et liquide-vapeur). L’optimisation des conditions opératoires a ainsi permis d’obtenir un saut thermique maximal de 12,4°C pour le mélange n-heptane / DMF pris comme référence. En faisant varier les propriétés des composés autour de celles de ce mélange de référence, un saut maximum de 32°C a été calculé pour un mélange fictif. L’étude de 17 mélanges réels a permis atteindre 21°C de saut thermique. Une liste d’autres mélanges à étudier a été établie. A l’aide d’une unité pilote d’une puissance de 4kW, des mesures expérimentales des performances du cycle modifié de TTAD pour le mélange n-heptane / DMF ont été réalisées et démontré la faisabilité de ce cycle même si le saut thermique de 11°C atteint au maximum est inférieur à celui calculé par simulationThis work is a study of a new type of Absorption-Demixing Heat Transformer (ADHT), using a mixture exhibiting a miscibility gap at low temperature. In this cycle, the separation step is performed by settling obtained after cooling the mixture. The separation is then energetically free and enables to reach thermal yields higher than those obtained for classical absorption heat transformers where separation is done by distillation.In order to find suitable working mixtures to reach temperature lift of 50°C, a numerical simulation tool was developed to calculate ADHT performances. This tool enabled to calculate thermal yield and thermal lift for different values of operating parameters (molar feed ratio, number of stages of rectification column) and different properties of working mixtures (Cp, Lv, parameters characterizing liquid-liquid and liquid-vapour equilibria). The best operating conditions allowed reaching a 12,4°C thermal lift for the n-heptane / DMF mixture takes as a reference mixture. By varying the mixture properties around the values of the reference mixture properties, a maximal thermal lift of 32°C was reached for an imaginary mixture. 17 real mixtures were also studied and enabled to reach a 21°C temperature lift. A list of other working mixtures that should be suitable was established. A 4 kW ADHT pilot unit was designed and built. The technical feasibility of this cycle was then experimentally demonstrated with this unit. A maximum temperature lift of 11°C was measured with the n-heptane / DMF mixture that is lower than the values calculated by simulation