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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

MYOSIN-XVA IS KEY MOLECULE IN ESTABLISHING THE ARCHITECTURE OF MECHANOSENSORY STEREOCILIA BUNDLES OF THE INNER EAR HAIR CELLS

Hadi, Shadan 01 January 2018 (has links)
Development of hair cell stereocilia bundles involves three stages: elongation, thickening, and supernumerary stereocilia retraction. Although Myo-XVa is known to be essential for stereocilia elongation, its role in retraction/thickening remains unknown. We quantified stereocilia numbers/diameters in shaker-2 mice (Myo15sh2) that have deficiencies in “long” and “short” isoforms of myosin-XVa, and in mice lacking only the “long” myosin-XVa isoform (Myo15ΔN). Our data showed that myosin-XVa is largely not involved in the developmental retraction of supernumerary stereocilia. In normal development, the diameters of the first (tallest)/second row stereocilia within a bundle are equal and grow simultaneously. The diameter of the third row stereocilia increases together with that of taller stereocilia until P1-2 and then either decreases almost two-fold in inner hair cells (IHCs) or stays the same in outer hair cells (OHCs), resulting in a prominent diameter gradation in IHCs and less prominent in OHCs. Sh2 mutation abolishes this gradation in IHCs/OHCs. Stereocilia of all rows grow in diameters nearly equally in Myo15sh2/sh2 IHCs and OHCs. Conversely, ΔN mutation does not affect normal stereocilia diameter gradation until ~P8. Therefore, myosin-XVa “short” isoform is essential for developmental thinning of third row stereocilia, which causes diameter gradation within a hair bundle.
22

Quantifying the characteristics of fine aggregate using direct and indirect test methods

Alqarni, Ali Saeed 19 March 2014 (has links)
The characteristics of fine aggregates, such as shape, angularity, and surface texture, have been shown to influence the performance of concrete and asphalt mixtures and to play an important role in obtaining valuable properties of early age concrete such as workability, and compatibility. However, the measurement of fine aggregate characteristics is not easy. In the present study, 26 fine aggregates, covering a wide spectrum of mineralogy, were examined using direct and indirect test methods in order to evaluate the shape, angularity, and surface texture, as well as to analyze the gradation. The direct test methods, such as AIMS and Camsizer, which provide a digital image of the aggregates proved to be the best. However, the cost of such systems can limit the use of digital imagining systems in practice. The indirect test methods which provide an estimate of aggregate surface characteristics, such as uncompacted void test, mortar flow test, compressive strength test, and flakiness test gave variable results. The uncompacted void test (Method A) was shown to be the most accurate indirect test method. The Camsizer and the sieve analysis test produced identical gradation analysis results when an adequate sample was used. General correlations were developed between the direct and indirect test methods. The non-approved fine aggregates on the TxDOT’s list were analyzed and compared to those of the approved fine aggregates to see whether they could be successfully used. It was found that both LS-5 and LS-8 had good results—even better than the results of some of the approved fine aggregates. Thus, they could be successfully used. / text
23

Ageing of Asphalt Mixtures : Micro-scale and mixture morphology investigation

Das, Prabir Kumar January 2014 (has links)
There are many variables that affect the viscoelastic properties of asphalt mixtures with time, among which age hardening may be considered one of the important ones. Age hardening of asphalt mixtures is an irreversible process, which contributes to a reduction of the durability of pavements and eventually increases the maintenance cost. Beside the environmental effects, ageing in asphalt mixture depends on the physicochemical properties of bitumen and mixture morphology which is a combined effect of aggregate packing, porosity, air void distribution and their interconnectivity. Thus, a clear understanding on the physicochemical properties of bitumen and mixture morphology may help to predict the performance of asphalt mixtures, which will contribute to longer-lasting and better performing pavements. When looking at the bitumen at micro-scale, one can see microstructures appearing under certain conditions which can be partially explained by the interaction of the individual phases. Since the thermo-rheological behavior of bitumen depends largely on its chemical structure and intermolecular microstructures, studying these can lead to understanding of the mechanism, speed and conditions under which this phase behavior occurs. Linking this to the changes in properties of bitumen can thus lead to better understanding of the causes of ageing, its dominant parameters and the resulting diminished mechanical response. To investigate ageing in asphalt pavements, along with physicochemical properties of bitumen one needs to also focus on the influence of mixture morphology.  It is known that asphalt mixtures with similar percentages of air-voids can have different morphologies and thus can age differently. Prediction of ageing behavior without considering the influence of mixture morphology may thus lead to erroneous conclusions and non-optimal mix design. Hence, it is important to understand the interplay between the mixture morphology and ageing susceptibility and relate this to the long term mixture performance. The aim of this Thesis was to develop fundamental understanding on ageing in asphalt mixtures that can contribute to the asphalt community moving away from the currently used accelerated ageing laboratory tests and empirical models that can lead to erroneous conclusions. To reach this aim, experimental and numerical micro-scale analyses on bitumen and meso-scale investigations on mixture morphology have been performed which, collectively, allowed for the development of a method for the prediction of asphalt field ageing, incorporating both mixture morphology and micro-scale bitumen mechanisms. For this, first, the mechanisms of surface ageing and diffusion controlled oxidative ageing were identified. Secondly, the influence of mixture morphology on asphalt ageing susceptibility was investigated. Procedures to determine the controlling parameter were then developed and an empirical framework to quantify the long-term field ageing of asphalt mixtures was set-up. For this, a combination of experimental and numerical methods was employed. An extensive experimental study was carried out to understand the fundamental mechanisms behind the micro-structural phase appearance and the speed or mobility at which they change. Atomic Force Microscopy (AFM) was utilized at different temperatures to investigate the phase separation behavior for four different types of bitumen and co-relate it with the Differential Scanning Calorimetry (DSC) measurements. Based on the experimental findings, it was concluded that the observed phase separation is mainly due to the wax/paraffin fraction presence in bitumen (Paper I). A hypothesis was developed of the appearance of a thin film at the specimen surface due to ageing which is creating a barrier, restricting thus the microstructures to float towards the surface. Furthermore, investigation showed that depending on the bitumen and exposure types this surface thin film is water soluble and thus the moisture damage becomes more severe with the ageing of asphalt pavement (Paper II and IV). A new empirical relation to obtain the primary structure coating thickness was established utilizing mixture volumetric properties and gradation using a large set of data from different literature sources. It was found that the enhanced morphological framework can be used to optimize the long term performance of asphalt mixtures (Paper III).  Thereafter, the effect of diffusion controlled oxidative ageing on different mixture morphologies based on oxidative ageing mechanism of bitumen and diffusion-reaction process was investigated using the Finite Element Method (FEM). From the FE analyses, the effect of air-void distribution and their interconnectivity combined with the aggregate packing was shown to have a significant effect on age hardening (Paper IV). It was shown that focusing only on the percentage of air-void as the main predictive ageing parameter may lead to an erroneous conclusion and non-optimal predictions of long-term behavior.  To replace such approaches, a new way to predict the long-term ageing was proposed in this Thesis, utilizing the found influences of mixture morphology and fundamental mechanism. Though additional mechanisms and non-linear coupling between them may be still needed to reach the ‘ultimate’ ageing prediction model, the current model was found to be a significant improvement to the currently used methods and may lead the way towards further enhancing the fundamental knowledge towards asphalt mixture ageing (Paper V). / <p>QC 20140509</p>
24

Compressibility Of Various Coarse-grained Fill Materials In Dry And Wet Loading Conditions In Oedometer Test

Kayahan, Ahmet 01 January 2003 (has links) (PDF)
The use of coarse-grained fill materials has grown significantly in recent years especially on account of their use in dams and transportation networks. This study investigates compressibility of various coarse-grained fill materials in dry and wet loading conditions in oedometer test. Four materials were used in the experiments, which falls into GP, GW, GM and GC categories respectively. GP material is a weathered rock obtained from Eymir Lake region. This material was chosen especially to be able to investigate degradation and particle breakage due to compaction and compression. GW, GM and GC materials were obtained by using the material called &lsquo / bypass&rsquo / which is a fill material used in the construction of metro of Eryaman. Using these four materials, large-scale double oedometer tests were carried out to investigate compressibility in both dry and wet conditions. The double oedometer testing technique is used to investigate the effect of soaking on compressibility behaviour of compacted fill materials. Various compactive efforts were used in the compaction stage to investigate the effect of compactive effort on compressibility and degradation of the four gravelly materials. Gradations of the post-test samples were obtained and particle breakage due to compaction using various compactive efforts and particle breakage due to compression were determined. It is found that amount of compression does not necessarily depend on the dry density of the material and fine fraction is also a dominating property regarding the compressibility in coarse-grained fill materials. The vertical strains induced by soaking are on the order of 12% - 20% of the compression measured in dry loading case for the well-graded coarse-grained fill materials tested. Besides, there is significant particle breakage in the compaction process and no further particle breakage in the oedometer test for GP material.
25

Dvouvrstvý koberec drenážní s asfaltem modifikovaným pryžovým granulátem / Double Layer Porous Asphalt with Aspahlt-rubber Binder

Klimeš, Petr January 2012 (has links)
The possibilities of double layer porous asphalt usage and rules for design of porous asphalt mixtures are introduced in this work. The porous asphalt mixtures PA 8, PA 11 and PA 16 are designed with different content of asphalt-rubber according to Marshall Test method. The water sensitivity, drainability, particle loss of these PA are determined. The permanent deformation and drainability of double layer PA 8 and PA 11 were also determined. The possibility of usage of this double layer porous asphalt with expected decreasing of traffic noise was proved.
26

On the sacramentality of marriage : the divergence of canon law and theology and the inability to maintain the presumption of facere quod facit ecclesia

Pothier, Glen Joseph 11 1900 (has links)
The CIC/83, the living law (ius vigens) of the Latin Catholic Church, contains 110 canons on marriage in cc. 1055 – 1165. [The 1990 Code of Canons of the Eastern Churches contains a similar section, cc. 776 – 866]. The sacred canons, in general, are a compilation of theological statements that are presented in juridical terms. The canons on marriage, like those of the other sacraments, commence with a theological statement defining the essence of the sacrament. The first canon, c. 1055, states that (§1) the marriage covenant, for the baptized, has been raised to the dignity of a sacrament by Christ the Lord and that (§2) a valid marriage contract cannot exist between baptized persons without being a sacrament. A requirement of c. 1099 is that one must not be in error (error iuris) concerning the unity, indissolubility, or the sacramental dignity of marriage. Additionally, c. 1101, §2 states that when by a positive act of the will one excludes marriage itself or an essential element or an essential property, that marriage is invalid. The expectation of cc. 1099 and 1101, therefore, is that sacramentality be included at the time of exchange of consent. From the time of the scholastics, contract and sacrament have been identified as one for the baptized, hearkening to a time when civil legislation attempted to subvert the authority and oversight of the Church regarding (sacramental) marriage. At the Second Vatican Council, the constitution Gaudium et spes reinterpreted marriage as a covenantal relationship between man and woman. A covenant and a contract are not identical terms. More importantly, marriage was again seen as a covenant, and as a covenant, for the baptized, it Father Glen J. Pothier 2 is sacramental. Sacrosanctum Concilium, which set forth principles for the reform of the sacramental and liturgical life of the Latin Church, stated that sacraments presuppose faith. The International Theological Commission identified that there are members of the baptized faithful, Catholic or non- Catholic, who are unbelievers, who may have been baptized as children but have had no further faith elucidation, or, as members of non-Catholic ecclesial communities, do not believe in the seven sacraments of the Catholic Church, or, in particular, that marriage is a sacrament. Such persons would not, then, understand that sacramentality must be exchanged on the day of marriage. Rotal jurisprudence has reflected this change. In addition to the presumption that sacraments require faith, another presumption exists when the Church expects that the baptized marry according to the mind of the Church (the mens Ecclesiae), that is, facere quod facit Ecclesia, ([by] doing what the Church does). But in a society that is weakened by divorce, secularism, and a lack of understanding of what the Catholic Church understands by the sacrament of marriage, this presumption needs to be reexamined. Through research on the historical development of theological and canonical principles, and by means of independent studies of large groups of baptized Catholics and non-Catholics, it becomes increasingly clear that the theologico-juridico principles of c. 1055 and the sacramentality of marriage must be revisited. / Systematic Theology & Theological Ethics / D. Th. (Systematic Theology & Theological Ethics)
27

Contraintes syntaxiques et sémantiques sur l'intensification implicite: un cas non standard de la construction intensive de conséquence

Karenova, Kristyna 10 January 2014 (has links)
Cette these porte sur differents aspects syntaxiques et semantiques de l'intensification implicite dans une construction du francais non standard du type "Marie est belle qu'on en reste ebahi". Cette construction se caracterise par la presence d'un modificateur propositionnel (la prop-que) jouant le role d'un evaluateur de mesures extremes liees au predicat de la proposition matrice ("belle"). Ce modificateur opere sur des echelles de mesures et delimite la mesure reelle en la mettant en rapport avec la consequence qu'il exprime. Comme ce type d'evaluation correlative definit aussi la construction intensive de consequence (CIC), ou l'intensification est lexicalement realisée par les marqueurs d'intensité "tellement", "si", etc., nous proposons que la construction non standard represente un type implicite de la CIC. La CIC-implicite constitue un nouvel objet d'etude pour la description et la formalisation dans le cadre de la grammaire generative (Chomsky 1993, 1995, 2000). L'objectif principal de cette these est de fournir une description detaillee des comportements de la CIC-implicite, d'identifier les contraintes qui la regissent et de proposer un lien derivationnel entre cette derniere et la CIC-explicite. Une comparaison systematique des proprietes des deux CIC montre que les realisations de la CIC-implicite sont plus restreintes. Les restrictions incluent, entre autres, l'impossibilite de l'enchassement par un verbe factif et l'absence de la force interrogative. Une ligne directe peut etre etablie entre les differentes restrictions en termes de la notion pragmatique d'assertion et de la presence du locuteur. Notre derivation de la CIC-implicite, basee sur l'analyse de la CIC-explicite par association tardive proposee par Bhatt et Pancheva (2004, 2007), formalise la notion d'assertion au niveau de la peripherie gauche avec une projection dediee (Haegeman 2006 ; Speas et Tenny 2003). Cette projection, ainsi que l'association de la prop-que modificatrice, permettent d'interpreter et de legitimer la categorie vide qui realise l'intensification dans la CIC-implicite.
28

Contraintes syntaxiques et sémantiques sur l'intensification implicite: un cas non standard de la construction intensive de conséquence

Karenova, Kristyna 10 January 2014 (has links)
Cette these porte sur differents aspects syntaxiques et semantiques de l'intensification implicite dans une construction du francais non standard du type "Marie est belle qu'on en reste ebahi". Cette construction se caracterise par la presence d'un modificateur propositionnel (la prop-que) jouant le role d'un evaluateur de mesures extremes liees au predicat de la proposition matrice ("belle"). Ce modificateur opere sur des echelles de mesures et delimite la mesure reelle en la mettant en rapport avec la consequence qu'il exprime. Comme ce type d'evaluation correlative definit aussi la construction intensive de consequence (CIC), ou l'intensification est lexicalement realisée par les marqueurs d'intensité "tellement", "si", etc., nous proposons que la construction non standard represente un type implicite de la CIC. La CIC-implicite constitue un nouvel objet d'etude pour la description et la formalisation dans le cadre de la grammaire generative (Chomsky 1993, 1995, 2000). L'objectif principal de cette these est de fournir une description detaillee des comportements de la CIC-implicite, d'identifier les contraintes qui la regissent et de proposer un lien derivationnel entre cette derniere et la CIC-explicite. Une comparaison systematique des proprietes des deux CIC montre que les realisations de la CIC-implicite sont plus restreintes. Les restrictions incluent, entre autres, l'impossibilite de l'enchassement par un verbe factif et l'absence de la force interrogative. Une ligne directe peut etre etablie entre les differentes restrictions en termes de la notion pragmatique d'assertion et de la presence du locuteur. Notre derivation de la CIC-implicite, basee sur l'analyse de la CIC-explicite par association tardive proposee par Bhatt et Pancheva (2004, 2007), formalise la notion d'assertion au niveau de la peripherie gauche avec une projection dediee (Haegeman 2006 ; Speas et Tenny 2003). Cette projection, ainsi que l'association de la prop-que modificatrice, permettent d'interpreter et de legitimer la categorie vide qui realise l'intensification dans la CIC-implicite.
29

THICKNESS VARIABILITY EFFECTS ON THE PROPERTIES OF UNSTABILIZED FULL DEPTH RECLAIMED AGGREGATES

Haque, Rizwana 14 March 2014 (has links)
Inadequate financial allocation for road maintenance is a threat to the impaired rural highways in Atlantic Canada. The conventional means of pavement rehabilitation has been to place a hot mix asphalt concrete overlay on the existing worn out pavement which is only a short term adjustment. The purpose is to provide a smooth wearing surface at a low cost. This traditional way of pavement repair does not fix the damage embedded within the pavement structure. After a certain extent of time the cracks in the original pavement start to reflect to the smooth new wearing surface, causing deterioration on the overlay. The advanced approach which is becoming more popular is the application of Full Depth Reclamation (FDR). This technique helps to repair the extensively defective roads by pulverizing the flexible pavement along with a fraction of the underlying damaged base layer. Thus a damage free base layer can be obtained by stabilizing and recompacting the pulverized materials. FDR is a sustainable and an environmentally beneficial repair method as it re-uses the in-situ materials. FDR process has been used around the world for over 25 years yet confronts some difficulties regarding the fluctuation in the strength of materials in various projects. It is inferred that some of these difficulties are due to the variability and poor quality in the restored materials. The variability in the recycled base layer is a result of currently utilizing a retroactive depth control method to attain a specific blend of asphalt concrete to granular base for the pulverized materials. Two FDR projects applying two different pulverization control methods (conventional retroactive and GPR depth control methods) were analyzed to investigate the improvements in consistency of the restored materials by using Ground Penetrating Radar (GPR). A wide range of asphalt concrete/base layer blend ratio was detected in retroactive control section, while consistent blend ratio was maintained in GPR survey by mapping the variability in the depth of pavement and sub-dividing the test sections accordingly. A GPR controlled constant blend ratio during pulverization displayed improvements in consistency of materials, physical and mechanical properties and performance as anticipated. The materials obtained by using the conventional retroactive depth control method exhibited higher variability in grain size distribution, optimum moisture content, optimum density, California Bearing Ratio, resilient modulus and shear strength. All materials from both projects exhibited excessive air voids and inadequate fines content as the as-obtained particles acted as conglomerated particles and enough fines were not generated after the pulverization. It is recommended that efficient quality control, precise specifications and appropriate pulverization methods will provide more reliable and impressive FDR pavements. / This thesis contains research on unstabilized full depth reclaimed aggregates properties
30

On the sacramentality of marriage : the divergence of canon law and theology and the inability to maintain the presumption of facere quod facit ecclesia

Pothier, Glen Joseph 11 1900 (has links)
The CIC/83, the living law (ius vigens) of the Latin Catholic Church, contains 110 canons on marriage in cc. 1055 – 1165. [The 1990 Code of Canons of the Eastern Churches contains a similar section, cc. 776 – 866]. The sacred canons, in general, are a compilation of theological statements that are presented in juridical terms. The canons on marriage, like those of the other sacraments, commence with a theological statement defining the essence of the sacrament. The first canon, c. 1055, states that (§1) the marriage covenant, for the baptized, has been raised to the dignity of a sacrament by Christ the Lord and that (§2) a valid marriage contract cannot exist between baptized persons without being a sacrament. A requirement of c. 1099 is that one must not be in error (error iuris) concerning the unity, indissolubility, or the sacramental dignity of marriage. Additionally, c. 1101, §2 states that when by a positive act of the will one excludes marriage itself or an essential element or an essential property, that marriage is invalid. The expectation of cc. 1099 and 1101, therefore, is that sacramentality be included at the time of exchange of consent. From the time of the scholastics, contract and sacrament have been identified as one for the baptized, hearkening to a time when civil legislation attempted to subvert the authority and oversight of the Church regarding (sacramental) marriage. At the Second Vatican Council, the constitution Gaudium et spes reinterpreted marriage as a covenantal relationship between man and woman. A covenant and a contract are not identical terms. More importantly, marriage was again seen as a covenant, and as a covenant, for the baptized, it Father Glen J. Pothier 2 is sacramental. Sacrosanctum Concilium, which set forth principles for the reform of the sacramental and liturgical life of the Latin Church, stated that sacraments presuppose faith. The International Theological Commission identified that there are members of the baptized faithful, Catholic or non- Catholic, who are unbelievers, who may have been baptized as children but have had no further faith elucidation, or, as members of non-Catholic ecclesial communities, do not believe in the seven sacraments of the Catholic Church, or, in particular, that marriage is a sacrament. Such persons would not, then, understand that sacramentality must be exchanged on the day of marriage. Rotal jurisprudence has reflected this change. In addition to the presumption that sacraments require faith, another presumption exists when the Church expects that the baptized marry according to the mind of the Church (the mens Ecclesiae), that is, facere quod facit Ecclesia, ([by] doing what the Church does). But in a society that is weakened by divorce, secularism, and a lack of understanding of what the Catholic Church understands by the sacrament of marriage, this presumption needs to be reexamined. Through research on the historical development of theological and canonical principles, and by means of independent studies of large groups of baptized Catholics and non-Catholics, it becomes increasingly clear that the theologico-juridico principles of c. 1055 and the sacramentality of marriage must be revisited. / Philosophy, Practical and Systematic Theology / D. Th. (Systematic Theology & Theological Ethics)

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