Дисертації з теми "Shape dependence"

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1

Weir, Brian S. "MONTE CARLO SIMULATIONS OF SHAPE DEPENDENCE IN MAGNETIC ANTIDOT ARRAYS." Miami University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=miami1155065484.

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2

Dinsdale, Michael J. "The scheme-dependence of power correction fits to event shape observables." Thesis, Durham University, 2005. http://etheses.dur.ac.uk/3011/.

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A recent analysis by the DELPHI collaboration showed that if one uses an "optimised" choice of renormalization scale, some e+e(^-) event shape means can be described without significant power corrections. Motivated by this, in this thesis optimised scales (and schemes) are applied to similar observables. First, abrief review of QCD and scale/scheme optimisation is given. Then, the distributions of the e+e(^-) event shapes l-thrust and heavy-jet mass are studied within the Method of Effective Charges, including performing a next-to-leading log resummation of the effective charge beta function. There is some reduction in the apparent size of power corrections, but the resummed results behave pathologically in the 2-jet limit. Next, the Principle of Minimal Sensitivity is applied to the choice of renormalization and factorization scales for event shape means defined in the Breit frame of ep BIS. This has little effect on the perturbative predictions and large power corrections are still required. However, if one introduces separate renormalization scales for the qγ* and gγ* sub-processes, a substantial reduction in the size of the power corrections is seen for most observables.
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3

Huang, Weimin. "Shape memory alloys and their application to actuators for deployable structures." Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299009.

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4

Morgan, Katharine Elizabeth. "The scale dependence of perturbative QCD predictions for e+e− event shape moments and LHC observables." Thesis, Durham University, 2013. http://etheses.dur.ac.uk/6374/.

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Perturbative QCD predictions that are truncated at fixed order have an unphysical dependence on the renormalisation procedure. We investigate two methods of avoiding scale and scheme dependence in QCD predictions of physical observables: the Effective Charges (ECH) method and the Principle of Minimal Sensitivity (PMS). The ECH method is used to avoid the renormalisation scale and scheme dependence of fixed-order predictions of event shape moments. Values of αs(MZ) are extracted from e+e− data using both ECH and the physical scale method in the MS scheme. The ECH method at NLO is found to perform better than standard MS perturbation theory (MS PT) when applied to means of event shapes. However ECH at NNLO functions less well than at NLO, and the ECH method also fails to describe data for higher moments of event shapes. Pad ́e Approximant methods are used to estimate missing higher orders in the perturbative expansions, a technique that works especially well for MS PT applied to the higher moments. We also examine the effect of adding non-perturbative power corrections to the perturbative approximations. It is found that power corrections are insufficient to counteract the undesirable behaviour of ECH at NNLO. The PMS method is used to provide predictions of the b ̄b and tt ̄total cross-sections at the Tevatron and the LHC. Hadronic cross-sections depend on the factorisation scale as well as the renormalisation scale. PMS is applied by searching for stationary points on the cross-section surface in the space of the two scales. The PMS method predicts substantially larger b ̄b cross-sections than using standard diagonal scale choices. For tt ̄ production, however, there is very little difference observed between the two methods. Both produce predictions that are in good agreement with the current experimental data.
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5

Saghaian, Sayed M. "SHAPE MEMORY BEHAVIOR OF SINGLE CRYSTAL AND POLYCRYSTALLINE Ni-RICH NiTiHf HIGH TEMPERATURE SHAPE MEMORY ALLOYS." UKnowledge, 2015. http://uknowledge.uky.edu/me_etds/65.

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NiTiHf shape memory alloys have been receiving considerable attention for high temperature and high strength applications since they could have transformation temperatures above 100 °C, shape memory effect under high stress (above 500 MPa) and superelasticity at high temperatures. Moreover, their shape memory properties can be tailored by microstructural engineering. However, NiTiHf alloys have some drawbacks such as low ductility and high work hardening in stress induced martensite transformation region. In order to overcome these limitations, studies have been focused on microstructural engineering by aging, alloying and processing. Shape memory properties and microstructure of four Ni-rich NiTiHf alloys (Ni50.3Ti29.7Hf20, Ni50.7Ti29.3Hf20, Ni51.2Ti28.8Hf20, and Ni52Ti28Hf20 (at. %)) were systematically characterized in the furnace cooled condition. H-phase precipitates were formed during furnace cooling in compositions with greater than 50.3Ni and the driving force for nucleation increased with Ni content. Alloy strength increased while recoverable strain decreased with increasing Ni content due to changes in precipitate characteristics. The effects of the heat treatments on the transformation characteristics and microstructure of the Ni-rich NiTiHf shape memory alloys have been investigated. Transformation temperatures are found to be highly annealing temperature dependent. Generation of nanosize precipitates (~20 nm in size) after three hours aging at 450 °C and 550 °C improved the strength of the material, resulting in a near perfect dimensional stability under high stress levels (> 1500 MPa) with a work output of 20–30 J cm– 3. Superelastic behavior with 4% recoverable strain was demonstrated at low and high temperatures where stress could reach to a maximum value of more than 2 GPa after three hours aging at 450 and 550 °C for alloys with Ni great than 50.3 at. %. Shape memory properties of polycrystalline Ni50.3Ti29.7Hf20 alloys were studied via thermal cycling under stress and isothermal stress cycling experiments in tension. Recoverable strain of ~5% was observed for the as-extruded samples while it was decreased to ~4% after aging due to the formation of precipitates. The aged alloys demonstrated near perfect shape memory effect under high tensile stress level of 700 MPa and perfect superelasticity at high temperatures up to 230 °C. Finally, the tensioncompression asymmetry observed in NiTiHf where recoverable tensile strain was higher than compressive strain. The shape memory properties of solutionized and aged Ni-rich Ni50.3Ti29.7Hf20 single crystals were investigated along the [001], [011], and [111] orientations in compression. [001]-oriented single crystals showed high dimensional stability under stress levels as high as 1500 MPa in both the solutionized and aged conditions, but with transformation strains of less than 2%. Perfect superelasticity with recoverable strain of more than 4% was observed for solutionized and 550 °C-3h aged single crystals along the [011] and [111] orientations, and general superelastic behavior was observed over a wide temperature range. The calculated transformation strains were higher than the experimentally observed strains since the calculated strains could not capture the formation of martensite plates with (001) compound twins.
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6

Stokes, Kimberly. "A Closer Look: Uncovering The Reasons Schools And Businesses Partner And How The Partnerships Shape Curriculum And Pedagogy." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1228339564.

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7

Gauthier-Faille, Gail. "Outpatient treatment for substance dependence : using empirical findings about retention and substance use outcomes to shape treatment services." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100370.

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The literature has indicated that frequently examined patient variables at intake have shown mixed results in the prediction of dropout from outpatient substance abuse treatment. In this research sociodemographic characteristics, substance use and psychological problem severity at intake were examined as predictors of early dropout in 411 patients enrolled in a 6-month outpatient substance abuse treatment program. Early dropout was defined as participation of less than 6 weeks, the first phase of treatment. Another focus of the research was to determine how patients who dropped out of treatment early fared in terms of substance use at 6 months compared to those retained longer. It was found that being younger, unmarried or not cohabitating, and having a greater severity of employment problems at intake were associated with early treatment dropout. Substance abuse and psychological problem severity at intake were not associated with dropout from the first phase of treatment. Patients who left treatment early had some reduction in alcohol consumption at 6-month follow-up, but overall, those retained in treatment longer had better alcohol and drug use outcomes at 6 months. Both the outcomes on retention and substance use were examined in order to explore possible solutions to dropout from the perspective of health services. Despite the improvements in substance abuse for patients retained longer than 6 weeks, it was determined that only 40% of patients were retained for 6 months, thereby indicating that the majority of patients had not received the planned 6-month intervention. In response to these facts, a brief intervention consisting of 5 individual therapy sessions based on coping skills and motivational enhancement strategies was designed and manualized with participation of the clinical staff. Following this, a randomized clinical trial was conducted with 72 patients, and substance use at 6-month follow-up was compared between the brief intervention and the conventional treatment groups. At 6 months, both the brief intervention and conventional treatment groups had reductions in alcohol use compared to intake, but no conclusions could be made about drug use. The implications of the findings for substance abuse treatment service delivery are discussed.
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8

Bugana, Marco. "Mathematical Modeling to Investigate Antiarrhythmic Drug Side Effects: Rate-Dependence Role in Ionic Currents and Action Potentials Shape in the O’Hara Model." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/3529/.

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Sudden cardiac death due to ventricular arrhythmia is one of the leading causes of mortality in the world. In the last decades, it has proven that anti-arrhythmic drugs, which prolong the refractory period by means of prolongation of the cardiac action potential duration (APD), play a good role in preventing of relevant human arrhythmias. However, it has long been observed that the “class III antiarrhythmic effect” diminish at faster heart rates and that this phenomenon represent a big weakness, since it is the precise situation when arrhythmias are most prone to occur. It is well known that mathematical modeling is a useful tool for investigating cardiac cell behavior. In the last 60 years, a multitude of cardiac models has been created; from the pioneering work of Hodgkin and Huxley (1952), who first described the ionic currents of the squid giant axon quantitatively, mathematical modeling has made great strides. The O’Hara model, that I employed in this research work, is one of the modern computational models of ventricular myocyte, a new generation began in 1991 with ventricular cell model by Noble et al. Successful of these models is that you can generate novel predictions, suggest experiments and provide a quantitative understanding of underlying mechanism. Obviously, the drawback is that they remain simple models, they don’t represent the real system. The overall goal of this research is to give an additional tool, through mathematical modeling, to understand the behavior of the main ionic currents involved during the action potential (AP), especially underlining the differences between slower and faster heart rates. In particular to evaluate the rate-dependence role on the action potential duration, to implement a new method for interpreting ionic currents behavior after a perturbation effect and to verify the validity of the work proposed by Antonio Zaza using an injected current as a perturbing effect.
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9

Leithäuser, Christian [Verfasser]. "Controllability of Shape-Dependent Operators and Constrained Shape Optimization for Polymer Distributors / Christian Leithäuser." München : Verlag Dr. Hut, 2013. http://d-nb.info/1033041246/34.

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10

Narayanan, Radha. "Shape-Dependent Nanocatalysis and the Effect of Catalysis on the Shape and Size of Colloidal Metal Nanoparticles." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6878.

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From catalytic studies in surface science, it has been shown that the catalytic activity is dependent on the type of metal facet used. Nanocrystals of different shapes have different facets. This raises the possibility that the use of metal nanoparticles of different shapes could catalyze different reactions with different efficiencies. The catalytic activity is found to correlate with the fraction of surface atoms located on the corners and edges of the tetrahedral, cubic, and spherical platinum nanoparticles. It is observed that for nanoparticles of comparable size, the tetrahedral nanoparticles have the highest fraction of surface atoms located on the corners and edges and also have the lowest activation energy, making them the most catalytically active. Nanoparticles have a high surface-to-volume ratio, which makes them attractive to use compared to bulk catalytic materials. However, their surface atoms are also very active due to their high surface energy. As a result, it is possible that the surface atoms are so active that their size and shape could change during the course of their catalytic function. It is found that dissolution of corner and edge atoms occurs for both the tetrahedral and cubic platinum nanoparticles during the full course of the mild electron transfer reaction and that there is a corresponding change in the activation energy in which both kinds of nanoparticles strive to behave like spherical nanoparticles. When spherical palladium nanoparticles are used as catalysts for the Suzuki reaction, it is found that the nanoparticles grow larger after the first cycle of the reaction due to the Ostwald ripening process since it is a relatively harsh reaction due to the need to reflux the reaction mixture for 12 hours at 100 oC. When the tetrahedral Pt nanoparticles are used to catalyze this reaction, the tetrahedral nanoparticles transform to spherical ones, which grow larger during the second cycle. In addition, studies on the effect of the individual reactant have also provided clues to the surface catalytic process that is taking place. In the case of the electron transfer reaction, the surface catalytic process involves the thiosulfate ions binding to the nanoparticle surface and reacting with the hexacyanoferrate (III) ions in solution. In the case of the Suzuki reaction, the surface catalytic mechanism of the Suzuki reaction involves the phenylboronic acid binding to the nanoparticle surface and reacting with iodobenzene via collisional processes.
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11

Qiao, Lei Ph D. Massachusetts Institute of Technology. "Computational modeling of size-dependent superelasticity in shape memory alloys." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85763.

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Анотація:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 145-155).
The superelastic effect in shape memory alloys (SMAs) is attributed to the stress-induced reversible austenitic-martensitic phase transformations. It is characterized by the development of significant strains which are fully recoverable upon unloading, and also characterized by the stress-hysteresis in the loading and unloading cycle which corresponds to the energy dissipated during phase transformations. Recently, experiments have revealed size-dependent effects in the superelastic responses of SMAs at micro- and nanoscales. For instance, the CuAlNi microwires and submicron pillars show a substantially higher capacity for the energy dissipation than that of bulk samples, which offers a significant promise for the applications in protective materials. In this thesis, a continuum model is developed in order to improve our understanding of size effects in SMAs at small scales. The modeling approach combines classic superelastic models, which use the volume fraction as an internal variable to represent the martensitic phase transformation, with strain gradient plasticity theories. Size effects are incorporated through two internal length scales, an energetic length scale and a dissipative length scale, which correspond to the martensitic volume fraction gradient and its time rate of change, respectively. Introducing the gradient of the martensitic volume fraction leads to coupled macro- and microforce balance equations, where the displacements and the martensitic volume fraction are both independent fields. A variational formulation for the temporally-discretized coupled macro- and microforce balance equations is proposed, as well as a computational framework based on this formulation. A robust and scalable parallel algorithm is implemented within this computational framework, which enables the large-scale three-dimensional study of size effects in SMAs with unprecedented resolution. This modeling and computational framework furnishes, in effect, a versatile tool to analyze a broad range of problems involving size effects in superelasticity with the potential to guide microstructure design and optimization. In particular, the model captures the increase of the stress hysteresis and strain hardening in bulk polycrystalline SMAs for decreasing grain size, as well as the increase of the residual strain for decreasing pillar size in NiTi pillars. The model confirms that constraints like grain boundaries and the surface Ti oxide layer are responsible for the size-dependent superelasticity in SMAs.
by Lei Qiao.
Ph. D.
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12

Ugail, Hassan. "Time-dependent shape parameterisation of complex geometry using PDE surfaces." Nashboro Press, 2004. http://hdl.handle.net/10454/2686.

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13

Svensson, Lena. "Dependent form : Finding form by using two shapes dependent on eachother." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-12995.

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The interest of this work is found in the potential ways of constructinggarments and how form can be explored within that field.This work explores how one can use draping as a construction methodapplied on garments to change the traditional shape and to create new formand silhouettes. The possibility to create form by using two depending components is thefoundation and aim of this collection. It will embrace different qualities inmaterials and challenge traditional garments and the view on how we usuallyand suppose to wear these garments. Garments are dependent mostly on the body of the wearer in first hand, onecould say that this work challenges that order when the two pieces aredeveloped being dependent on each other in first hand. Through relationship of fastening and uniting materials I will explore thepossibilities within form and volume and push the expression within thebasic forms within a traditional wardrobe. My aim is to further investigate the possibilities within womens wear bylooking at material, color and silhouette through a deconstructed way ofdraping. A collection of seven outfits is the result of this work. The outfits willchallenge the field of construction and how we traditionally make garments.The shapes and expression will be based on the interaction between garmentsand the materials.
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14

Wong, Truman. "Dynamics of platelet shape change and aggregation size-dependent platelet subpopulations." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61778.

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15

Volino, Marco. "View-dependent representation of shape and appearance from multiple view video." Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/810240/.

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Over the past decade, markerless performance capture, through multiple synchronised cameras, has emerged as an alternative to traditional motion capture techniques, allowing the simultaneous acquisition of shape, motion and appearance. This technology is capable of capturing the subtle details of human motion, e.g. clothing, skin and hair dynamics, which cannot be achieved through current marker based capture techniques. Markerless performance capture has the potential to revolutionise digital content creation in many creative industries, but must overcome several hurdles before it can be seen as a practical mainstream technology. One limitation of the technology is the enormous size of the generated data. This thesis addresses issues surrounding compact appearance representation of virtual characters generated through markerless performance capture, optimisation of the underlying 3D geometry and delivery of interactive content over the internet. Current approaches to multiple camera texture representation effectively reduce the storage requirements by discarding huge amounts of view dependent and dynamic appearance information. This information is important for reproducing the realism of the captured multiple view video. The first contribution of this thesis introduces a novel multiple layer texture representation (MLTR) for multiple view video. The MLTR preserves dynamic, view dependent appearance information by resampling the captured frames into a hierarchical set of texture maps ordered by surface visibility. The MLTR also enables computationally efficient view-dependent rendering by pre-computing visibility testing and reduces projective texturing to a simple texture lookup. The representation is quantitatively evaluated and shown to reduce the storage cost by > 90% without a significant effect on visual quality. The second contribution outlines the ideal properties for the optimal representation of 4D video and takes steps in achieving this goal. Using the MLTR, spatial and temporal consistency is enforced using a Markov random field framework, allowing video compression algorithms to make further storage reductions through increased spatial and temporal redundancies. An optical flow-based multiple camera alignment method is also introduced to reduce visual artefacts, such as blurring and ghosting, that are caused by approximate geometry and camera calibration errors. This results in clearer and sharper textures with a lower storage footprint. In order to facilitate high quality free-viewpoint rendering, two shape optimisation methods are proposed. The first combines the strengths of the visual hull, multiple view stereo and temporally consistent geometry to match visually important features using a non-rigid iterative closest point method. The second is based on a bundle adjustment formulation which jointly refines shape and calibration. While, these methods achieve the objective of enhancing the geometry and/or camera calibration parameters, further research is required to improve the resulting shape. Finally, it is shown how the methods developed in this thesis could be used to deliver interactive 4D video to consumers via a WebGL enabled internet browser, e.g. Firefox or Chrome. Existing methods for parametric motion graphs are adapted and combined with an efficient WebGL renderer to allow interactive 4D character delivery over the Internet. This demonstrates for the first time that 4D video has the potential to provide interactive content via the internet which opens this technology up to the widest possible audience.
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16

Aristorenas, George V. (George Villanueva). "Time-dependent behavior of tunnels excavated in shale." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/13197.

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17

Sawer, Francesca K. "The role of shame in alcohol dependence : narratives from those in recovery." Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/811750/.

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A relationship between shame and alcohol dependence has been reported in the literature, however the precise nature of this relationship is largely unexplored. A review of the literature suggested that experiencing shame is considered to be a risk factor of relapse. The drinking of alcohol temporarily relieves the negative feelings of shame therefore reinforcing further drinking and maintaining addictive behaviour. As a consequence, learning how to cope with shame without drinking, may improve recovery. On the other hand, some evidence suggests that experiencing shame may be helpful for developing reasons for stopping drinking and also a necessary protective factor that helps to prevent relapse. This study sought to explore how shame is experienced and understood by those ‘in recovery’ from alcohol dependence, by looking at the different ways that shame is spoken about in personal narratives. Eight participants were recruited from Alcoholic Anonymous (AA) groups and invited to tell their story of recovery. Transcripts were analysed using a narrative approach, focusing on how participants narrated their stories and made sense of their experiences, by identifying specific narrative techniques used to talk about shame. An analysis across all transcripts then identified narrative themes in relation to shame and from this a tentative model of shame in alcohol dependence was proposed. A discussion of the findings evaluated evidence for the model, taking into account the results from this study and those from existing theory and research, whilst identifying areas of further research that are needed. Clinical implications in relation to addressing shame in recovery are also discussed.
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18

Holmberg, Rurik. "Survival of the Unfit : Path Dependence and the Estonian Oil Shale Industry." Doctoral thesis, Linköping : Linköping University, Department of Technology and Social Change, 2008. http://www.bibl.liu.se/liupubl/disp/disp2008/arts427s.pdf.

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19

Miao, Yi. "Shape-Dependent Molecular Recognition of Specific Sequences of DNA by Heterocyclic Cations." Digital Archive @ GSU, 2006. http://digitalarchive.gsu.edu/chemistry_diss/4.

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SHAPE-DEPENDENT MOLECULAR RECOGNITION OF SPECIFIC SEQUENCES OF DNA BY HETEROCYCLIC CATIONS by YI MIAO Under the Direction of Dr. W. David Wilson ABSTRACT DB921 and DB911 are biphenyl-benzimidazole-diamidine isomers with a central para- and meta-substituted phenyl group, respectively. Unexpectedly, linear DB921 has much stronger binding affinity with DNA than its curved isomer, DB911. This is quite surprising and intriguing since DB911 has the classical curved shape generally required for strong minor groove binding while DB921 clearly does not match the groove shape. Several biophysical techniques including thermal melting (Tm), circular dichroism (CD), biosensor-surface plasmon resonance (SPR), and isothermal titration calorimetry (ITC) have been utilized to investigate the interactions between these compounds and DNA. The structure of the DB921-DNA complex reveals that DB921 binds to DNA with a reduced twist of the biphenyl for better fit of DB921 into the minor groove. A bound water molecule complements the curvature of DB921 and contributes for tight binding by forming H-bonds with both DNA and DB921. Structure-affinity relationship studies of a series of DB921 analogs show that the benzimidazole group is one of the key groups of DB921 for its strong binding to the minor groove. Thermodynamic studies show that the stronger binding of DB921 is due to a more favorable binding enthalpy compared to DB911 even though the complex formation with DNA for these compounds are all predominantly entropically driven. DB921 also has more negative heat capacity change than DB911. The initial studies of inhibition of the interaction between an AT hook peptide of HMGA proteins and its target DNA by a set of diamidine AT-minor groove binders using biosensor-SPR technique show that the inhibitory ranking order is consistent with that of binding affinity and linear-shaped DB921 still has excellent inhibitory effects. These heterocyclic cations rapidly inhibit the binding of DBD2 peptide to the DNA and may only block the specific AT binding of the peptide without hindering the non-specific binding interaction. The results of this project have shown that DB921 represents a new novel effective minor groove binder that does not fit the traditional model and is a potential inhibitor for DNA/protein complexes. INDEX WORDS: Molecular recognition, DNA binding, Minor groove binding, Linear shape, Compound curvature, Binding affinity, Binding kinetics, Thermodynamics, Surface plasmon resonance, Isothermal titration calorimetry, Inhibition
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20

Schütte, Maria [Verfasser]. "On shape sensitivity analysis for 3D time-dependent Maxwell's equations / Maria Schütte." Paderborn : Universitätsbibliothek, 2017. http://d-nb.info/1127109979/34.

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21

Oh, Joonyoung. "Numerical study of micro-scale damage evolution in time dependent fracture mechanics." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1117645391.

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Анотація:
Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xvi, 147 p.; also includes graphics Includes bibliographical references (p. 143-147). Available online via OhioLINK's ETD Center
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22

Li, Wen. "Solute diffusion in the bone lacunar-canalicular system its dependency on molecular weight, shape, and charge /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 75 p, 2009. http://proquest.umi.com/pqdweb?did=1694433001&sid=9&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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23

Gong, Yin. "An Experimental Investigation of Pressure-dependent and Time-dependent Fracture Aperture and Permeability in Barnett Shale." Thesis, University of Louisiana at Lafayette, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1553880.

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U.S. domestic shale-gas production is economic owing to the new completion practice of horizontal wells and multiple hydraulic fractures. The performance of these fractures is improved through the placement of proppant. The change in the stress can affect fracture conductivity considerably. The objective of this study is to experimentally determine the impact of rock stress and time on aperture and permeability of hydraulic fractures in shale gas reservoirs.

Seven experiments were conducted to measure pressure and time dependent closure and permeability of hydraulic fractures created in Barnett shale under different confining pressure. Result shows that pressure dependence of permeability of these fractures obeys Walsh’s permeability models. Time dependence of permeability at high stresses reveals that proppant embedment occurred to the Barnett shale cores.

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24

Pei, Haochun. "Shape and Surface Property Dependent Phytotoxicity of Silver and Gold Nanoparticles to Lactuca sativa (Lettuce)." OpenSIUC, 2013. https://opensiuc.lib.siu.edu/theses/1144.

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Engineered nanomaterials (ENMs) are currently used in a wide range of manufacturing processes and applications thanks to the numerous technical and economic benefits derived from the incorporation of ENMs in these processes. Accompanying these benefits are the potential toxicity of ENMs to humans and the environment. Previous research has shown that ENMs display strong toxicity to plants. Earlier research suggested that physicochemical properties of ENMs such as their size, shape, and surface properties considerably affect toxicity; however, the unique physicochemical properties of ENMs affect their phytotxicity to plants is still unknown. This research evaluated the phytotoxicity of silver and gold nanoparticles to lettuce plants in both sand and hydroponic conditions by monitoring a wide range of plant physiological parameters after their exposure to these nanoparticles with two coating materials (citrate and polyvinylpyrrolidone) and three shapes (sphere, wire and plate) at 200 and 1000 µg/L concentrations. The result from lettuce in hydroponics showed that spherical silver or gold nanoparticles with both coatings did not affect biomass significantly, but both of silver and gold nanoparticles at 1000 µg/L slightly reduced the biomass compared to the control lettuce. The effect on root leakage was similar, but spherical silver nanoparticles had slightly higher damage due to root leakage than gold nanoparticles at the same concentration. The lettuce treated to citrate-coated gold nanoparticles significantly reduced chlorophyll content compared to citrate-coated silver nanoparticles. Secondly, when it came to the surface coating, the plant exposed to 1000 µg/L spherical citrate- coated silver or gold nanoparticles had higher root leakage compared to PVP-coated nanoparticles. Both of 1000 µg/L spherical citrate-coated silver nanoparticles and gold nanoparticles significantly reduced chlorophyll content compared to PVP-coated nanoparticles. Thirdly, for different shapes of PVP-coated silver nanoparticles, the plant exposed to plate shaped and sphere shaped silver nanoparticles had significantly lower biomass compared to the wire shaped silver nanoparticles. The plant exposed to spherical silver nanoparticles had the lowest chlorophyll content between plate shaped and wire shaped silver nanoparticles. In addition, the result from lettuce in sand medium showed that the biomass production and the root leakage showed no significant difference between spherical citrate-coated, spherical PVP-coated, and silver ions at 200 µg/L. In conclusion, different nanoparticles affected different physiological processes of plants differently.
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25

Aebig, Trudy J. "Cell cycle-dependent association of plectin 1b regulates mitochondrial morphology and function." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1307440587.

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26

Mckernan, Rosanne. "An experimental investigation into the stress dependent fluid transport properties of mudstones." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/an-experimental-investigation-into-the-stress-dependent-fluid-transport-properties-of-mudstones(17efbf46-29a3-44d1-afd3-194709418c90).html.

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Measuring transport properties of rock samples under stress is essential to understanding and predicting the migration of fluids within the Earth's crust. Mudrocks play an essential role in petroleum systems as they are often the source rock and may act as a seal due to their low permeability. With increasing production from unconventional reservoirs where the mudrock is source, reservoir and seal, there is now even greater demand to understand the permeability and storativity of mudstones and tight sandstones. When hydraulic fracture treatment is used to enhance production, flow of hydrocarbons into the fractures will be ultimately controlled by the matrix permeability. Knowledge of the fluid transport properties of mudstones is currently hindered by a scarcity of published experimental data. In this thesis, a combination of permeability and ultrasonic velocity measurements allied with image analysis is used to distinguish the primary microstructural controls on effective stress dependent permeability. Permeabilities of cylindrical samples of Whitby Mudstone and Eagle Ford Shale have been measured using the oscillating pore pressure method at confining pressures ranging between 30-95 MPa and pore pressures ranging between 1-80 MPa. The results show that samples must be pressure cycled in order to obtain a reproducible behaviour, after which the relationship between permeability and effective stress can be described by an exponential law. The permeability of the Whitby Mudstone samples ranges between 7 ×10-21 m2 and 2 ×10-19 m2 (7 nd to 188 nd) and decreases by ~1 order of magnitude across the applied effective stress range. The permeability of the Eagle Ford Shale samples is slightly higher ranging between 2 ×10-18 m2 and 42 ×10-18 m2 (2 μd to 42 μd) and decreases by half an order of magnitude across the applied effective stress range. Permeability is shown to be more sensitive to changes in pore pressure than changes in confining pressure yielding values of alpha between 1.1-2.1 for Whitby Mudstone and 1.6-4.6 for Eagle Ford Shale. Gas slippage (Klinkenberg) effects are restricted to pore pressures below 10 MPa in the Whitby Mudstone and therefore do not affect the results presented. The permeability-effective stress relationship is thus empirically described using a modified effective stress law in terms of confining pressure, pore pressure and a Klinkenberg effect. Use of a simple reservoir model demonstrates that if pressure dependent permeability is not taken into account, substantial overestimation of gas flow rate and original gas in place will be made from well tests. Changes in ultrasonic velocity and pore volume were related to the observed loss of permeability with increasing effective stress, providing further insight into the nature of the permeability-controlling pore network. Combining the petrophysical data with pore conductivity modelling and microstructural analysis shows that at low effective stresses, permeability is controlled by a network of long, thin crack-like pores associated with grain boundaries. At high effective stresses, these cracks are closed and fluid is restricted to flowing through a less permeable network of higher aspect ratio, stiffer, nm-scale pores in the clay matrix. Applying the methods developed in the present work to different mudstones with a range of compositions and textures will help to refine understanding of the variability in fluid-conducting pore networks, thereby advancing the interpretation of data from well logs and well tests used for reservoir evaluation.
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27

El-Galfy, Ahmed Mohamed Mohamed. "The structure of cross-sectional dependence in analysts forecasts of earnings per share: evidence and implications." Thesis, University of Manchester, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488103.

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A number of papers have provided empirical evidence suggesting that analysts' earnings forecasts do not conform to Muthian rationality. Analysts' earnings forecasts have been found, in both early research and more recent studies, to be irrational, i.e., biased, inefficient or both (see for instance: Brown et al., 1985 and Easterwood and Nutt, 1999). De Bondt and Thaler (1990), in particular, documented generalised overreaction in the analysts' forecasts, showing that the forecasts, tracked by I/B/E/S, are too optimistic and too extreme to be considered rational. Conversely, a notable study developed by Keane and Runkle (1998) claimed that analysts' forecasts of corporate profits may be rational after all if we take into account two complications: (1) the cross-sectional correlation in contemporaneous forecast errors across analysts and firms, and (2) discretionary asset write-downs, which affect earnings but are intentionally ignored by analysts when they make earnings forecasts. They proposed an estimation technique for testing the rationality of analysts' forecasts based on the GMM of Hansen (1982). This thesis challenges the finding that cross-sectional correlation "explains" the irrationality of analysts' earnings forecasts. The thesis further investigates Keane and Runkle's (1998) claim. The rationality of analysts' earnings forecasts per share is tested in the current study using two data-set samples and employing two complementary empirical methods. Firstly, the quality of "annual" analysts' earnings forecasts for a "balanced panel" of US firms is investigated. In particular, I test for forecast accuracy by using two alternative forecast errors metrics, that are: the "mean absolute percent forecast errors" and the "mean percent forecast errors". Then, I evaluate the superiority of analysts' earnings forecasts by comparing the forecasts of my balanced panel of firms with those generated by a variety of alternative benchmark models, using Theil's if metric which evaluates the adequacy of analysts' forecasts based on the mean-square error of their predictions. Next, the unbiasedness and efficiency are tested by using OLS regression of the actual change of EPS on the forecasted change of EPS. The study is extended in this part to investigate the degree to which the analysts vary in their predictive performance and the impact of some inappropriate forecasts on the adequacy of analysts' forecasts as a whole. Secondly, GMM correction to the variance-covariance matrix is employed to test the rationality of "quarterly" analysts' earnings forecasts per share, allowing for cross-sectional dependence, as well as controlling for the extreme special items. I use in this part the framework advanced by Keane and Runkle (1998), and also introduce some extensions to their framework to try to improve the understanding of this issue.
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28

Liu, Xiaomeng. "Study on composition dependent phase stability of Ni50MnxIn50-x shape memory alloys by ab-initio simulation." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0050.

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Une série de calculs de premier principe pour étudier la transformation martensitique des alliages Ni-Mn-In a été mise en œuvre en utilisant la méthode du pseudopotentiel de VASP et la méthode de densité de charge complète par EMTO-CPA dans le cadre de la théorie de la fonctionnelle de la densité (DFT). Pour l'alliage stoechiométrique Ni50Mn25In25, l'effet de Coulomb efficace et des paramètres d'échange (U + J) sur la stabilité de phase, les propriétés structurelles et magnétiques a été étudié. Les paramètres du réseau et la stabilité de phase varient avec les différents couplages U et J dans l'austénite cubique L21. Cependant, la bande interdite présente toujours une liaison métallique dans l'alliage cubique Ni50Mn25In25. Pour déterminer l'effet des atomes de Mn en excès sur la préférence de la structure martensitique, la distorsion tétragonale a été utilisée dans les alliages Ni50MnxIn50-x avec différentes teneurs en Mn. La distorsion tétragonale à l'état fondamental, résolue en énergie, révèle que l'excès de Mn change la structure stable préférée de la structure cubique parfaite L21 en structures déformées tétragonales. De plus, pour découvrir une préférence plus précise de la structure de la martensite, les énergies de formation ont été calculées. Les résultats montrent que la structure orthorhombique est préférée aux concentrations de Mn faibles (entre 29 at.% et 40 at.%), Tandis que la structure tétragonale L10 est plus stable aux concentrations Mn plus élevées (supérieures à 40 at.%). De plus, l'effet de la concentration en Mn sur les propriétés magnétiques a également été étudié. Avec l'augmentation de la teneur en Mn en excès, le moment magnétique augmente linéairement dans la structure ferromagnétique cubique L21, alors qu'il varie dans les deux types de martensite. L'excès de Mn pourrait conduire à la coexistence du ferromagnétisme et de l'antiferromagnétisme. L'apparition de l'antiferromagnétisme pourrait être attribuée à l'interaction antiferromagnétique Ni-Mn dans la martensite tétragonale. De plus, les effets de la concentration en Mn et des contributions excitées thermiquement (y compris les contributions vibratoires, électroniques et magnétiques) sur la stabilité de phase de l'austénite et de la martensite de 0 K à des températures finies dans les alliages à mémoire de forme Ni50MnxIn50-x typés Heusler ont également été étudiés. Les résultats montrent qu'à 0 K, les différences d'énergie entre la martensite non modulée (NM) et l'austénite deviennent négatives lorsque du Mn supplémentaire est ajouté, indiquant que le Mn ajouté stabilise la martensite et favorise la transformation martensitique. Aux températures finies, il a été révélé que les entropies vibrationnelles des deux phases augmentent avec l'augmentation de la température pour toutes les teneurs en Mn. Sous les deux effets (température et teneur en Mn), l'austénite a une entropie vibrationnelle plus grande que la martensite, ce qui indique que l'entropie vibrationnelle contribue à favoriser la transformation martensitique. La teneur en Mn et la température montrent une influence similaire sur les entropies électroniques des deux phases. Et les moments magnétiques augmentent linéairement avec la teneur en Mn, cependant, l'influence de la température est relativement faible. Au-dessus de 100 K, le moment magnétique de l'austénite est plus élevé que celui de la martensite dans l’alliage ferromagnétique Ni50Mn29.25In20.75, suggérant que l'entropie magnétique contribue de manière similaire à favoriser la transformation martensitique, comme les entropies vibratoires et d'excitation électronique. Le présent travail fournit des connaissances fondamentales pour comprendre la transformation martensitique des alliages Ni-Mn-In stœchiométriques, qui pourraient être utilisés pour concevoir des alliages ferromagnétiques à mémoire de forme avec des performances fonctionnelles améliorées
A series of first-principle calculations to discover the martensitic transition of the Ni-Mn-In alloys were implemented using the pseudopotential method by VASP and the full charge density method by EMTO-CPA within the framework of the Density Functional Theory (DFT). In the stoichiometric Ni50Mn25In25 alloy, the effect of effective Coulomb and exchange parameters (U + J) on the phase stability, structural and magnetic properties was studied. The lattice parameters and the phase stability vary with the U and J couplings in the cubic L21 austenite. However, the bandgap is still showing metallic bonding in the cubic Ni50Mn25In25 alloy. To figure out the effect of excess Mn atoms on the preference of the martensite structure, the tetragonal distortion was employed in the off-stoichiometric Ni50MnxIn50-x alloys with different Mn contents. The calculations were conducted with the optimization of the magnetic structure, where the stoichiometric Ni50Mn25In25 alloy was served as the reference. The ground state-energy-resolved tetragonal distortion reveals that the excess Mn changes the preferred stable structure from the perfect cubic L21 structure to the tetragonally distorted structures. Furthermore, to find out more accurate preference of the martensite structure, the formation energies were calculated. The results show that, the orthorhombic structure is preferred at lower Mn concentrations (between 29 at. % and 40 at. %), whereas the tetragonal L10 structure is more stable at the higher Mn concentrations (above 40 at. %). Moreover, the effect of the Mn concentration on the magnetic properties was also studied. With the increase of the excess Mn content, the magnetic moment increases linearly in the ferromagnetic cubic L21 structure, whereas it varies in the two kinds of martensite. The excess Mn could lead to the coexistence of ferromagnetism and antiferromagnetism. The appearance of the antiferromagnetism could be attributed to the Ni-Mn antiferromagnetic interaction in the tetragonal martensite. Furthermore, the effects of Mn concentration and thermally excited contributions (including the vibrational, electronic excitation and magnetic contributions) on the phase stability of austenite and martensite from 0 K to finite temperatures in Heusler type Ni50MnxIn50-x shape memory alloys were also studied. Results show that at 0 K, the energy differences between the non-modulated (NM) martensite and the austenite become negative when extra Mn is added, indicating that the added Mn stabilizes the martensite and promotes martensitic transformation. At finite temperatures, the three thermal contributions (the vibrational, electronic excitation and magnetic contributions) were further calculated based on the equilibrium structure at 0 K. It was revealed that the vibrational entropies of the two phases increase with the increase of the temperature for all Mn contents. Under the two effects (temperature and Mn-content), the austenite has a larger vibrational entropy than the martensite, which indicates that the vibrational entropy contributes to promoting the martensitic transition. The Mn content and the temperature show a similar influence on the electronic entropies of the two phases. And the magnetic moments increase linearly with the Mn content, however, the influence of temperature is relatively small. Above 100 K, the magnetic moment of the austenite is higher than that of the martensite in ferromagnetic Ni50Mn29.25In20.75 alloy, suggesting that the magnetic entropy makes a similar contribution to promote the martensitic transformation, like the vibrational and electronic excitation entropies. The present work provides fundamental knowledge to understand the martensitic transition of off-stoichiometric Ni50MnxIn50-x alloys, which could be used for the design of ferromagnetic shape memory alloys with improved functional performances
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29

Gur, S., S. K. Mishra, and G. N. Frantziskonis. "Thermo-mechanical strain rate-dependent behavior of shape memory alloys as vibration dampers and comparison to conventional dampers." SAGE PUBLICATIONS LTD, 2015. http://hdl.handle.net/10150/615541.

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A study on shape memory alloy materials as vibration dampers is reported. An important component is the strain rate-dependent and temperature-dependent constitutive behavior of shape memory alloy, which can significantly change its energy dissipation capacity under cyclic loading. The constitutive model used accounts for the thermo-mechanical strain rate-dependent behavior and phase transformation. With increasing structural flexibility, the hysteretic loop size of shape memory alloy dampers increases due to increasing strain rates, thus further decreasing the response of the structure to cyclic excitation. The structure examined is a beam, and its behavior with shape memory alloy dampers is compared to the same beam with conventional dampers. Parametric studies reveal the superior performance of the shape memory alloy over the conventional dampers even at the resonance frequency of the beam-damper system. An important behavior of the shape memory alloy dampers is discovered, in that they absorb energy from the fundamental and higher vibration modes. In contrast, the conventional dampers transfer energy to higher modes. For the same beam control, the stiffness requirement for the shape memory alloy dampers is significantly less than that of the conventional dampers. Response quantities of interest show improved performance of the shape memory alloy over the conventional dampers under varying excitation intensity, frequency, temperature, and strain rate.
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30

Trigeorgis, Christina Ariana. "An investigation of the relationship between shame and substance use : aggression, disclosure and self-related constructs in clients with drug dependence." Thesis, University of Surrey, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.600136.

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Objectives The central objective of this study was to investigate the relationship between shame and substance use. The Experiences of Shame Scale CESS) was used to differentiate between different sources of shame, namely character, behaviour and body shame. Drug-related shame was examined as a possible additional source of shame. The study also aimed to investigate potential constructs underlying the association between shame and substance use. Aggression was considered alongside the self-related concepts of self-ambivalence and self-esteem as potential mediators. Finally, the relationship between shame and distress disclosure was examined. Method 100 participants were recruited for the study; 50 poly-drug users were recruited from drug and alcohol services for the substance use (SU) group and 50 non-substance using participants were recruited online via mental health charities for the comparison group. The study used a cross-sectional design to investigate differences between the groups. Standardised self-report questionnaire measures were used. Results Findings indicate that the SU group participants scored higher on all ESS subscales. After adjusting for demographic differences between the groups, only differences on Character shame remained significant. Aggression was found to be a significant mediator of the relationship between Character shame and substance use. Findings also suggest that the highest level of shame experienced by SU participants is related to substance use. Moreover, self-ambivalence, self-esteem and willingness to disclose distress were associated with shame, regardless of substance use.
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31

Miller, Carol Diana. "Effects of economic development, trade dependency, and debt on women's share of the labor force: A cross-national study." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/252896.

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This is a cross-national study of determinants of women's share of the labor force. Previous research suggests that national rates of female share of the labor force are affected by economic development and international trade. Economic development has been linked to increased education opportunities for women, decreased fertility rates and increased gross national product per capita. These effects of economic development were suggested to improve women's economic opportunities. Some studies have focussed on the effects of foreign trade and finance on cross-national variations in female labor force participation rates. World-system researchers have recommended changes in methods and theory that suggest that the determinants of female labor force participation need to be reexamined. By using statistical methods recently introduced to cross-national research, as well as more recent data, I have tested hypotheses suggested by previous research for the decade of the 1980's. Specifically, previous research suggested that economic development increases and international trade generally decreases women's share of the labor force. This period was a tumultuous time in the world-economy. Many countries experienced debt crises and many attempted economic restructuring by focusing on exports of manufactured commodities instead of raw materials and agricultural goods. I have tested for the effects of these changes on changes in women's share of the labor force using data from the 60 countries for which data were available. Lowered fertility rates increased women's share of the labor force in the 1980's, but that was the only modernization indicator that had an effect. The proportion of a country's revenues obtained from exports affected women's share of the labor force, but this effect varied by levels of commodity concentration and exports in manufactured products. As commodity concentration increased, the positive effect of exports became less positive. As manufactured exports became a bigger proportion of all of a countries exports, the positive effect of exports as a source of a country's revenues on women's share of the labor force became more positive. Debt servicing and debt restructuring was not found to have an effect on women's share of the labor force in the 1980's.
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32

Amarh, Vincent. "Visualization of replication-dependent DNA double-strand break repair in Escherichia coli." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29596.

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Chromosomal replication is a source of spontaneous DNA double-strand breaks (DSBs). In E. coli, DSBs are repaired by homologous recombination using an undamaged sister template. During repair, the RecA protein polymerizes on single-stranded DNA generated at the site of the DSB and catalyses the search for sequence homologies on the undamaged sister template. This study utilized fluorescence microscopy to investigate the spatial and temporal dynamics of the RecA protein at the site of a replication-dependent DSB generated at the lacZ locus of the E. coli chromosome. The DSB was generated by SbcCD-mediated cleavage of a hairpin DNA structure formed on the lagging strand template of the replication fork by a long palindromic sequence. The tandem insertion of a recA-mCherry gene with the endogenous recA gene at the natural chromosomal locus produced no detectable effect on cell viability in the presence of DSB formation. During repair, the fluorescently-labelled RecA protein formed a transient focus, which was inferred to be the RecA nucleoprotein filament at the site of the replication-dependent DSB. The duration of the RecA focus at the site of the DSB was modestly reduced in a ΔdinI mutant and modestly increased in a ΔuvrD or ΔrecX mutant. Most cells underwent a period of extended cohesion of the sister lacZ loci after disappearance of the RecA focus. Segregation of the sister lacZ loci was followed by cell division, with each daughter cell obtaining a copy of the fluorescently-labelled lacZ locus. The RecA focus at the site of the DSB was observed predominantly between the mid-cell and the 1⁄4 position. In the absence of DSB formation, the lacZ locus exhibited dynamic movement between the mid-cell and the 1⁄4 position until the onset of segregation. Formation of the DSB and initiation of repair occurred at the spatial localization for replication of the lacZ locus while the downstream repair events occurred very close to the mid-cell. Genomic analysis of RecA-DNA interactions by ChIP-seq was used to demonstrate that the RecA focus at the lacZ locus was generated by the repair of the palindrome-induced DSB and not the repair of one-ended DSBs emanating from stalled replication forks at the repressor-bound operator arrays. This study has shown that the repair of a replication-dependent DSB occurs exclusively during the period of cohesion of the sister loci and the repair is efficiently completed prior to segregation of the two sister loci.
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33

Price, Lorraine. "Back to the beginning : an exploration of the treatment and effects of therapeutic regression to dependence in psychotherapeutic practice." Thesis, De Montfort University, 2014. http://hdl.handle.net/2086/10510.

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This research builds upon and explores an enigmatic set of experiences which theorists in the Object Relations tradition have characterised as regression to dependence, a return to a primitive, pre-verbal relational process presenting in some clients in psychotherapy. This research is a study of the concept of regression to dependence, its manifestation within the psychotherapy process, and facilitation within the therapeutic relationship. The Psychoanalytic theoretical positions on regression to dependence are explored, together with the Relational/Developmental perspective which recognises regression and its importance within psychotherapy. This exploration seeks to understand the experience of regression to dependence, how regression to dependence can be effectively worked within Integrative Psychotherapy, and makes recommendations for Integrative practitioners and theorists related to effective facilitation of clients, showing how the Relational/Developmental approach can effect repair. The study employs a qualitative methodology. A heuristic study was undertaken in which eleven practicing psychotherapists were interviewed and data was collected via semi-structured interviews. Most participants were interviewed twice, with a view to collecting data on both their personal experience as a client in psychotherapy and also their experiences as practitioners when working with clients who were experiencing regression to dependence. The transcripts from these interviews were analysed for emergent themes. The themes are discussed in the context of and with reference to the Psychoanalytic theoretical position and the Relational/Developmental perspective. An account is offered of how these experiences have come to be understood as recollecting difficulties in early infantile relationships. Reflections are made on the essence and qualities of a therapy that can facilitate regression to dependence in order to promote healing. Recommendations are made for the practice of Integrative Psychotherapy and the training of Integrative Psychotherapists in order to prepare them for this work. These recommendations for therapists include; having sufficient preparation, knowledge and understanding to be able to recognise and work with a regressive process emerging in the client; having an understanding of the need to facilitate this process for some clients; and to be aware of the need for particular adaptations in the therapeutic stance in some circumstances, and the difficulties which may arise. Recommendations are also offered regarding the support needed for the therapist whilst working with this process, which include the need for ongoing personal therapy, and supervision. The researcher’s personal story is an intrinsic part of the research, and as an integral part of this study is in accordance with the heuristic and autoethnographic styles, and with the practice of Integrative Psychotherapy, where the use of self is seen as a crucial clinical tool in the therapeutic process. Throughout this study reflexivity has been used regarding the personal experiences of the researcher as client, therapist and researcher.
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34

Liao, Chen-Ting, Xuan Li, Daniel J. Haxton, Thomas N. Rescigno, Robert R. Lucchese, C. William McCurdy, and Arvinder Sandhu. "Probing autoionizing states of molecular oxygen with XUV transient absorption: Electronic-symmetry-dependent line shapes and laser-induced modifications." AMER PHYSICAL SOC, 2017. http://hdl.handle.net/10150/624049.

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We used extreme ultraviolet (XUV) transient absorption spectroscopy to study the autoionizing Rydberg states of oxygen in an electronically- and vibrationally-resolved fashion. XUVpulse initiates molecular polarization and near-infrared pulse perturbs its evolution. Transient absorption spectra show positive optical-density (OD) change in the case of ns sigma(g) and nd pi(g) autoionizing states of oxygen and negative OD change for nd sigma(g) states. Multiconfiguration time-dependent Hartree-Fock (MCTDHF) calculations are used to simulate the transient absorption and the resulting spectra and temporal evolution agree with experimental observations. We model the effect of nearinfrared perturbation on molecular polarization and find that the laser-induced phase-shift model agrees with the experimental andMCTDHF results, while the laser-induced attenuation model does not. We relate the electronicstate- symmetry-dependent sign of the OD change to the Fano parameters of the static absorption line shapes.
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35

Kretschmer, Lorenz Christoph Benjamin [Verfasser], Dirk [Akademischer Betreuer] Busch, Hendrik [Gutachter] Poeck, Marc [Gutachter] Schmidt-Supprian, and Dirk [Gutachter] Busch. "Antigen-dependence of cell cycle speed during priming shapes CD8+ T cell memory / Lorenz Christoph Benjamin Kretschmer ; Gutachter: Hendrik Poeck, Marc Schmidt-Supprian, Dirk Busch ; Betreuer: Dirk Busch." München : Universitätsbibliothek der TU München, 2021. http://d-nb.info/1231434503/34.

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36

Nardin, Chiara. "Seismic experimental analyses and surrogate models of multi-component systems in special-risk industrial facilities." Doctoral thesis, Università degli studi di Trento, 2022. https://hdl.handle.net/11572/362462.

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Nowadays, earthquakes are one of the most catastrophic natural events that have a significant human, socio-economic and environmental impact. Besides, based on both observations of damage following recent major/moderate seismic events and numerical/experimental studies, it clearly emerges that critical non-structural components (NSCs) that are ubiquitous to most industrial facilities are particularly and even disproportionately vulnerable to those events. Nonetheless and despite their great importance, seismic provisions for industrial facilities and their process equipment are still based on the classical load-and-resistance factor design (LRFD) approach; a performance-based earthquake engineering (PBEE) approach should, instead, be preferred. Along this vein, in recent years, much research has been devoted to setting computational fragility frameworks for special-risk industrial components and structures. However, within a PBEE perspective, studies have clearly remarked: i) a lack of definition of performance objectives for NSCs; ii) the need for fully comprehensive testing campaigns data on coupling effects between main structures and NSCs. In this respect, this doctorate thesis introduces a computational framework for an efficient and accurate seismic state-dependent fragility analysis; it is based on a combination of data acquired from an extensive experimental shake table test campaign on a full-scale prototype industrial steel frame structure and the most recent surrogate-based UQ forward analysis advancements. Specifically, the framework is applied to a real-world application consisting of seismic shake table tests of a representative industrial multi-storey frame structure equipped with complex process components, carried out at the EUCENTRE facility in Italy, within the European SPIF project: Seismic Performance of Multi-Component Systems in Special Risk Industrial Facilities. The results of this experimental research campaign also aspire to improve the understanding of these complex systems and improve the knowledge of FE modelling techniques. The main goals aim to reduce the huge computational burden and to assess, as well, when the importance of coupling effects between NSCs and the main structure comes into play. Insights provided by innovative monitoring systems were then deployed to develop and validate numerical and analytical models. At the same time, the adoption of Der Kiureghian's stochastic site-based ground motion model (GMM) was deemed necessary to severely excite the process equipment and supplement the scarcity of real records with a specific frequency content capable of enhancing coupling effects. Finally, to assess the seismic risk of NSCs of those special facilities, this thesis introduces state-dependent fragility curves that consider the accumulation of damage effects due to sequential seismic events. To this end, the computational burden was alleviated by adopting polynomial chaos expansion (PCE) surrogate models. More precisely, the dimensionality of a seismic input random vector has been reduced by performing the principal component analysis (PCA) on the experimental realizations. Successively, by bootstrapping on the experimental design, separate PCE coefficients have been determined, yielding a full response sample at each point. Eventually, empirical state-dependent fragility curves were derived.
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37

McKinney, Amy Marie. "Pollinator-mediated interactions between the invasive shrub Lonicera maackii and native herbs: The roles of shade, flowering phenology, spatial scale, and floral density." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1276309342.

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38

Bennala, Nezar. "Optimal tests for panel data." Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210081.

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Анотація:
Dans ce travail, nous proposons des procédures de test paramétriques et nonparamétriques localement et asymptotiquement optimales au sens de Hajek et Le Cam, pour deux modèles de données de panel. Notre approche est fondée sur la théorie de Le Cam d'une part, pour obtenir les propriétés de normalité asymptotique, bases de la construction des tests paramétriques optimaux, et la théorie de Hajek d'autre part, qui, via un principe d'invariance, permet d'obtenir les procédures nonparamétriques.

Dans le premier chapitre, nous considérons un modèle à erreurs composées et nous nous intéressons au problème qui consiste à tester l'absence de l'effet individuel aléatoire. Nous

établissons la propriété de normalité locale asymptotique (LAN), ce qui nous permet de construire des procédures paramétriques localement et asymptotiquement optimales (“les plus stringentes”)

pour le problème considéré. L'optimalité de ces procédures est liée à la densité-cible f1. Ces propriétés d'optimalité sont hautement paramétriques puisqu'elles requièrent que la densité sous-jacente soit f1. De plus, ces procédures ne seront valides que si la densité-cible f1 et la densité sous-jacent g1 coincïdent. Or, en pratique, une spécification correcte de la densité sous-jacente g1 est non réaliste, et g1 doit être considérée comme un paramètre de nuissance. Pour éliminer cette nuisance, nous adoptons l'argument d'invariance et nous nous restreignons aux procédures fondées sur des statistiques qui sont mesurables par rapport au vecteur des rangs. Les tests que nous obtenons restent valide quelle que soit la densité sous-jacente et sont localement et asymptotiquement les plus stringents. Afin d'avoir des renseignements sur l'efficacité des tests

fondés sur les rangs sous différentes lois, nous calculons les efficacités asymptotiques relatives de ces tests par rapport aux tests pseudo-gaussiens, sous des densités g1 quelconques. Enfin, nous proposons quelques simulations pour comparer les performances des procédures proposées.

Dans le deuxième chapitre, nous considérons un modèle à erreurs composées avec autocorrélation d'ordre 1 et nous montrons que ce modèle jouit de la propriété LAN. A partir de ce résultat, nous construisons des tests optimaux, au sens local et asymptotique, pour trois problèmes de tests importants dans ce contexte :(a) test de l'absence d'effet individuel et d'autocorrélation; (b) test de l'absence d'effet individuel en présence d'une autocorrélation non

spécifiée; et (c) test de l'absence d'autocorrélation en présence d'un effet individuel non spécifié. Enfin, nous proposons quelques simulations pour comparer les performances des tests pseudogaussiens

et des tests classiques.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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39

Sarkadi, Anna. "The borderland between care and self-care." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-4901-8/.

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40

Di, Novo Nicolò Giuseppe. "Water self-ejection, frosting, harvesting and viruses viability on surfaces: modelling and fabrication." Doctoral thesis, Università degli studi di Trento, 2022. https://hdl.handle.net/11572/355461.

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Анотація:
The wettability and phase change phenomena of water are ubiquitous on biological and artificial surfaces. Properties like water repellency, self-cleaning, coalescence induced condensation jumping, anti-frosting, and dew harvesting arise on surfaces with particular structures and chemistry and are of particular interest for energy and water saving. This thesis collects different studies of wettability and phase change on natural and artificial surfaces: growth and self-ejection of condensation droplets on micro and nanostructured surfaces we fabricated, their applications, the Sliding on Frost of condensation droplets observed on the Cotinus Coggygria leaf, the dew harvesting property of the Old Man of the Andes Cactus enhanced by distance coalescence through microgrooves and finally, a theoretical study of viruses viability in sessile droplets. The first chapter introduces the theoretical framework of wettability and phase changes on surfaces. In the second chapter, we present the self-ejection of condensation droplets from hydrophobic nanostructured microstructures. We modelled analytically the droplets jumping and fabricated surfaces to verify the predictions. The fabricated geometry was inspired by the modelling and the available fabrication techniques. We tested the surfaces in condensation conditions. Using a high frame rate camera coupled with a long working distance microscopy objective, we investigated the growth and ejection transient. We then compared the experimental self-ejection velocity for various structures geometry with our analytical models. In Chapter 3, we investigated the applications of the fabricated surfaces reported in Chapter 2. In Chapter 4, we explore the condensation frosting on the leaf of Cotinus Coggygria, native of our woods and with interesting hydrophobic properties. Covered by wax nanotubules, it exhibits coalescence-induced condensation jumpings that may be a useful cleaning tool. Furthermore, the frost is delayed but not only for the jumping. Surprisingly, at temperatures some degrees below zero, we observed what we called ‘droplet Sliding on Frost bridges’, that further delays frosting. We described the feasibility of this sliding in terms of dynamic contact angles of the surface and contact angles of supercooled water on ice. By capturing high temporal and spatial resolution videos we investigated the sliding on frost and droplet recalescence (fast dendrite growth that partially solidify the liquid). The responsible for the failure of sliding for temperatures from about -8 ° C down appears to be the advancing angle of water on ice that increases with the subcooling rather than the recalescence that blocks the drop in place. These results add a piece to the fundamental research on the supercooled water-ice-vapour interfaces. As it often happens, biological surfaces offer a starting point for the study of fundamental mechanisms and the development of artificial surfaces with optimized properties. In the Chapter 5, the multifunctional roles of hairs and spines in Old Man of the Andes Cactus (Oreocereus trolli) are studied. We study the morphology of the appendages, the hairs wettability, mechanical properties of both, and the dew formation on spines. The longitudinal microgrooves on the spines cause a particular phenomenon of distant coalescence (DC), in which smaller droplets flow totally or partially into larger ones through the microgrooves, with consequent accumulation of water in a few large drops. An earlier study has shown artificial micro-grooved surfaces that exhibit DC are more efficient than flat ones at collecting and sliding dew, and thus these cactus spines could act as soil dew conveyors. The agreement between our analytical model and experimental data verifies that the flow is driven by the Laplace pressure difference between the drops. This allowed us to obtain a general criterion for predicting the total or partial emptying of the smaller drops as a function of the dynamic contact angles of a surface. Based on this criterion, an hydrophilic material with small contact angle hysteresis would allow a greater number of complete drops emptying. The COVID-19 pandemic has raised the problem of contagion from airborne and deposited droplets. In the last chapter, we report the state of the art of experiments on the viability of viruses in deposited droplets. Up to date, it has been experimentally highlighted that the relative viability of some viruses (RV) depends on the material chemistry, temperature, and interestingly, on relative humidity (RH) with a U-shaped trend. One of the current hypotheses is that the cumulative dose of salt concentration (CD) affects RV. We model the RV of viruses in sessile droplets by inserting a RV-CD relation in a model of droplet evaporation. By considering a saline water droplet (one salt) as the simplest approximation of real solutions, we analytically simulate the time evolution of salt concentration, vapor pressure, and droplet volume varying contact angles, droplet sizes, and RH in the range 0–100%. The results elucidate some previously not yet well-understood dynamics, demonstrating how three main regimes—directly implicated in nontrivial experimental trends of virus RV—can be recognized as the function of RH. The proposed approach could suggest a chart of a virus fate by predicting its survival time at a given temperature as a function of RH and contact angle. We found a good agreement with experimental data for various enveloped viruses and predicted in particular for the Phi6 virus, a surrogate of coronavirus, the characteristic U-shaped dependence of RV on RH. Given the generality of the model, once experimental data are available that link the vulnerability of a certain virus (such as SARS-CoV-2) to the concentrations of salts or other substances in terms of CD, it is envisioned that this approach could be employed for antivirus strategies and protocols for the prediction/reduction of human health risks associated with SARS-CoV-2 and other viruses.
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41

Xiong, Qihua. "Shape dependence of physical properties of polar semiconducting nanowires." 2006. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-1307/index.html.

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42

Li, Chia-Yang, and 李家揚. "Sample shape and transverse field dependence of the planar Hall effect in Fe-Ni Permalloy." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/20293935934646387590.

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Анотація:
碩士
國立中正大學
物理系
89
A series of Permally film samples, in various shapes and thickness (t), were made. The sample width to length ratio W/L was changed from 0.1 to 1, The planar Hall effect (PHE) signal was found to be proportional to W/L and 1/t. Then, we studied how the planar Hall effect signal was affected by adding a transverse field Hy along the easy-axis direction. As a result, PHE sensitivity changed as a function of Hy. For the square sample, when t = 200 Å, Smax is as high as 575 Ω/T, and the inoperative range of Hy is the narrowest. In addition, another series of Permally film samples, in various shapes and thickness, were measured for the X-hystersesis loop and the Y-hystersesis loop by the biaxial VSM. We could find easy axis or hard axis quite accurately (within 0.5°) form a sequence of symmetrical graphs. This phenomenon could not be found by the conventional VSM.
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43

Zeng, Cyun-Lun, and 曾羣倫. "Dependence of the self-assembled fibrillary nanocomposites on sizes, shape anisotropy and concentration of magnetic nanoparticles." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/8mhzc2.

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Анотація:
碩士
國立交通大學
影像與生醫光電研究所
106
In this research, the dynamic process of aggregation that forms micro flower morphology in solution of lysozyme amyloid fibrils doped with magnetic nanoparticles of different sizes, shapes and proportional concentration during the process of drying as well as their final microstructures were investigated. The prepared lysozyme amyloid fibrils as well as their mixtures with magnetic particles, which were prepared by adding the nanoparticles to the fibrils solution after the process of fibrillation was done, were characterized using brightfield trans-illumination-mode optical microscope, atomic force microscopy (AFM) and scanning electron microscope (SEM). Bright field optical imaging bases upon photo absorptive property of the fibrils-nanoparticle composites clearly reveals the morphological features in microscale, and additionally, for the in vivo, live action of the time-dependent process of self-assembly of such composites composed of fibrillary structure incorporated with magnetic particles was optically elucidated at ambient temperature. Moreover, while results of AFM revealed delicate and peculiar association of fibrils with magnetic nanoparticles of different shapes and sizes, SEM images illustrate a stark difference in fine detailed final morphology of microstructures associated with spherical and spindle-like nanoparticles. Our results indicated that the interaction between fibrils solution and the nanoparticles commence right after mixing, the dynamic process of forming dendritic structure resembling microflower morphology is on the order of minutes to an hour, and its final structure is highly dependent on the shape, size and concentration of magnetic nanoparticles doped in different concentration with fibril. Likewise, the influence of external magnetic field to the self-assembled MNPs-incorporated fibrillary composites was studied.
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44

Excell, Peter S., and Z. M. Hejazi. "Compact Superconducting Dual-Log Spiral Resonator with High Q-Factor and Low Power Dependence." 2002. http://hdl.handle.net/10454/3260.

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Анотація:
No
A new dual-log spiral geometry is proposed for microstrip resonators, offering substantial advantages in performance and size reduction at subgigahertz frequencies when realized in superconducting materials. The spiral is logarithmic in line spacing and width such that the width of the spiral line increases smoothly with the increase of the current density, reaching its maximum where the current density is maximum (in its center for ¿/2 resonators). Preliminary results of such a logarithmic ten-turn (2 × 5 turns) spiral, realized with double-sided YBCO thin film, showed a Q.-factor seven times higher than that of a single ten-turn uniform spiral made of YBCO thin film and 64 times higher than a copper counterpart. The insertion loss of the YBCO dual log-spiral has a high degree of independence of the input power in comparison with a uniform Archimedian spiral, increasing by only 2.5% for a 30-dBm increase of the input power, compared with nearly 31% for the uniform spiral. A simple approximate method, developed for prediction of the resonant frequency of the new resonators, shows a good agreement with the test results.
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45

Sadeghi, F., A. Yazdanpanah, A. Abrishamkar, F. Moztarzadeh, A. Ramedani, S. Pouraghaie, H. Shirinzadeh, et al. "Shape-controlled silver NPs for shape-dependent biological activities." 2017. http://hdl.handle.net/10454/17024.

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Анотація:
No
The most important issue during synthesis of nanoparticles (NPs) is to avoid particle agglomeration and adhesion. There have been several attempts to use special substances such as organic surfactants, polymers and stable ligands for this purpose. In this study, silver NPs were synthesised with and without gelatin macromolecules, as a green natural biopolymer, which resulted in NPs with varying shapes and sizes. The effect of morphological characteristics on the antibacterial and antifungal properties of the synthesised NPs were studied, by comparing Gram-negative (Escherichia coli) versus Gram-positive (Staphylococcus aureus) bacteria as well as fungi (Candida albicans) by calculation of minimal inhibition concentration value. The results corresponded well with the assumptions on the effects of shape and size on the antibacterial and antifungal properties of the studied NPs.
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46

Hartl, Darren J. "Modeling of Shape Memory Alloys Considering Rate-independent and Rate-dependent Irrecoverable Strains." 2009. http://hdl.handle.net/1969.1/ETD-TAMU-2009-12-7573.

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This dissertation addresses new developments in the constitutive modeling and structural analysis pertaining to rate-independent and rate-dependent irrecoverable inelasticity in Shape Memory Alloys (SMAs). A new model for fully recoverable SMA response is derived that accounts for material behaviors not previously addressed. Rate-independent and rate-dependent irrecoverable deformations (plasticity and viscoplasticity) are then considered. The three phenomenological models are based on continuum thermodynamics where the free energy potentials, evolution equations, and hardening functions are properly chosen. The simultaneous transformation-plastic model considers rate-independent irrecoverable strain generation and uses isotropic and kinematic plastic hardening to capture the interactions between irrecoverable plastic strain and recoverable transformation strain. The combination of theory and implementation is unique in its ability to capture the simultaneous evolution of recoverable transformation strains and irrecoverable plastic strains. The simultaneous transformation-viscoplastic model considers rate-dependent irrecoverable strain generation where the theoretical framework is modfii ed such that the evolution of the viscoplastic strain components are given explicitly. The numerical integration of the constitutive equations is formulated such that objectivity is maintained for SMA structures undergoing moderate strains and large displacements. Experimentally validated analysis results are provided for the fully recoverable model, the simultaneous transformation-plastic yield model, and the transformation-viscoplastic creep model.
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47

Vera, Rosales Fabian 1986. "Evidence of Pressure Dependent Permeability in Long-Term Shale Gas Production and Pressure Transient Responses." Thesis, 2012. http://hdl.handle.net/1969.1/148240.

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The current state of shale gas reservoir dynamics demands understanding long-term production, and existing models that address important parameters like fracture half-length, permeability, and stimulated shale volume assume constant permeability. Petroleum geologists suggest that observed steep declining rates may involve pressure-dependent permeability (PDP). This study accounts for PDP in three potential shale media: the shale matrix, the existing natural fractures, and the created hydraulic fractures. Sensitivity studies comparing expected long-term rate and pressure production behavior with and without PDP show that these two are distinct when presented as a sequence of coupled build-up rate-normalized pressure (BU-RNP) and its logarithmic derivative, making PDP a recognizable trend. Pressure and rate field data demonstrate evidence of PDP only in Horn River and Haynesville but not in Fayetteville shale. While the presence of PDP did not seem to impact the long term recovery forecast, it is possible to determine whether the observed behavior relates to change in hydraulic fracture conductivity or to change in fracture network permeability. As well, it provides insight on whether apparent fracture networks relate to an existing natural fracture network in the shale or to a fracture network induced during hydraulic fracturing.
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48

Fritz, Karolina. "Applications of size and shape dependent properties of nanocrystalline lead sulfide and cadmium selenide." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=742465&T=F.

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49

Guo-DongHuang and 黃國棟. "Size and shape dependent preparation of Au-polymer Janus nanostructures and their potential biomedical applications." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/36831523888846870661.

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Анотація:
碩士
國立成功大學
化學系碩博士班
100
We developed a simple synthetic system to prepare acorn-like Au-polymer nanoparticles through a thermal inducing cross-linking reaction. The size and shape dependence studies indicate that Au nanoparticles strongly affected formation of Janus nanoparticles in size. Additionally, this approach can readily applied to PSMA analogues containing styrene and carboxylate moieties. Because of the size down to below 100 nm for the Janus nanoparticles, it is highly anticipated to further explore the capability of those asymmetric nanoparticles in biomedical applications, which has been greatly limited by the currently developed Janus microspheres. It has already been proved the applications in bioimaging and SERS sensing probe.
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50

Hsieh, Meng Shan, and 謝孟珊. "Synthesis of Shape-Controlled Ag3PO4 Crystals and Their Facet-Dependent Photocatalytic and Electrical Conductivity Properties." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/d866q5.

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