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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

Phenomenological Consequences of Heavy Right Handed Neutrinos

Rayyan, Saifuddin Ramadan 30 May 2007 (has links)
The discovery of neutrino mixing provides the possibility of a non vanishing CP violating phase in the neutrino mixing matrix. CP violation in the leptonic sector can be large enough to explain the matter-antimatter asymmetry in the universe. An indirect probe of CP violation is the experimental measurement of Electric Dipole Moment (EDM). CP violation has been discovered in the quark sector,but it contributes to lepton EDM at the 3-loop level. Neutrino masses can be generated in the standard model via the see-saw mechanism where heavy right-handed neutrinos mix with the weak-basis states. The Majorana nature of the seesaw type neutrinos generates new 2-loop diagrams that lead to a non-vanishing lepton EDM. Only estimates of the resulting EDM have been done in the literature. A full calculation of the 2-loop diagrams and the exact result is presented. / Ph. D.
22

Handedness & Autobiographical Memory: An Examination of Handedness and its Effects on Autobiographical Memory

Gosch, Austin 01 January 2018 (has links)
Previous research has shown that individuals who are inconsistently handed (IH) outperform consistently handed (IH) individuals on episodic and spatial memory tasks as well as many others. This current study examines whether handedness is related to a person’s ability to recall autobiographical memories (AM) - episodic memories about oneself. Participants were first asked to recall seven memories that will be cued by seven cue words: earth, friend, dream, power, love, trouble, and opinion. They later expanded on those memories to include more detail, then self-rated how well they were able to remember them on five aspects of AM (spatial layout, content, reliving, vividness, and belief) using a modified version of the Autobiographical Memory Questionnaire (AMQ). Ninety-seven participants (44.3% female, Age: 19 to 69 years) were included in the data analysis. All ninety-seven were recruited through Amazon’s Mechanical Turk system and were financially compensated for their time. Results showed no main effect of handedness on AM in regards to all five AM aspects tested, meaning IH’s did not outperform CH’s in regards to autobiographical memory recall.
23

Hygienické a pracovní návyky u levorukých žáků na 1. stupni ZŠ / Hygienic and Working Habits of Left-handed Pupils at Primary School

KOLÁŘOVÁ, Lucie January 2018 (has links)
The diploma thesis deals with the hygienic and working habits of left-handed pupils at the first level of elementary schools. The thesis is divided into two main parts, theoretical and research. The theoretical part of the thesis deals with basic information about laterality, brain hemispheres and school maturity. The main focus is on leftist and writing, where we focus on preparation for writing and individual hygiene and working habits of pupils. Problems of written speech and famous leftists are also mentioned. The research part is focused on the survey of the level of hygienic and working habits of primary school pupils. The research was conducted in the form of observations. The obtained results are graphically processed and interpreted. In conclusion, there is a recommendation for working with left-handers in practice.
24

Theoretical Investigation Of Metamaterials: Srr Structures And Periodic Arrays Of Thin Conducting Wires

Ates, Kazim Ozan 01 May 2008 (has links) (PDF)
In recent years, there has been an increasing interest on left handed metamaterials because of their possible innovative applications. The pioneer study introducing such materials was brought out by V. G. Veselago in 1968 [1]. In his work, Veselago proposed a medium having simultaneously negative electric permittivity and magnetic permeability and investigated its electromagnetic characteristics. He found out that the electric field, magnetic field and the propagation vector form a left handed triplet, thus named such materials as &ldquo / Left Handed Materials&rdquo / . Despite the significance of Veselago&rsquo / s inferences, the metamaterial theory stayed dormant for nearly 30 years. Towards the end of 1990s, the physically realizable left handed materials were built as the combination of two periodical structures / Split Ring Resonators (SRRs) and metallic thin wire arrays [4-5]. In this thesis, electrical and magnetic characteristics of the left handed metamaterials are theoretically investigated by using the analytical models for their permittivity and permeability functions with respect to frequency. For this purpose, first, two basic metamaterial structures / the Split Ring Resonators and Thin Metallic Wire Arrays are studied individually and their electrical and magnetic characteristics are examined. Finally, the composite left handed structure containing both SRRs and thin wires is studied to investigate the resulting simultaneous resonance properties and to estimate their overall effective permeability and permittivity functions.
25

Mating behaviour and the reproductive ecology of the big-handed crab, Heterozius rotundifrons A. Milne Edwards, 1867

Thompson, Glen Andrew January 1999 (has links)
The mating behaviour and reproductive ecology of the big-handed crab Heterozius rotundifrons was studied at Kaikoura between November 1997 and December 1998. H. rotundifrons was found at mean densities of 7.6 per m² (± 1.4) within the middle and low shore levels and varied little between seasons. The variance! mean ratio indicated that males and females aggregated within these shore levels. The sex ratio was significantly female biased during the majority of the year. Allometric growth rates indicated that males and females reached sexual maturity at 11 mm carapace width (CW). In males, spermatozoa production occurred between 9-9.99 mm CW. Ovigerous females were present every month except February. The first broods of the year were produced in March which coincides with a decrease in the female gonado-somatic index (GSI). These broods were incubated for approximately nine months whereas broods produced in August were incubated for only five months. Female brood production appeared to be cyclical, alternating between a winter incubation period and a summer incubation period. The completed cycle takes approximately three years with two broods produced during the cycle. Fecundity increased with female size but egg mortality was quite high (19%). Instantaneous mortality rate increased with increasing brood development. Females mate when recently moulted (soft-shelled). Although females moulted through out the year, in small numbers, there was a peak in female moulting during October and November. The operational sex ratio (OSR) was male biased during all months of the year. Females released an attractant prior to moulting which initiated pre-copulatory mate guarding by the male. Once the female moulted, copulation occurred approximately 6 h later. Copulation lasted for approximately 3 h and was followed by a period of post-copulatory mate guarding. Males increased the duration of post-copulatory mate guarding if another male was present. Large males out competed small males for receptive females. Males used their large cheliped to subdue competitors and to provide protection for the soft female. Mate guarding was shown to reduce cannibalism from other females. Spermatozoa are packaged in spermatophores within the vas deferens of males but are quickly dehisced within the spermathecae (ventral-type) of newly mated females. Last male to copulate probably achieves the highest level of paternity. Postcopulatory mate guarding by the male was found and ejaculates were found in discrete packets within the spermatheca. Sperm competition appeared to be important because large males displaced small males during copulation, males left when a female was still receptive and the females could retain sperm between moults. It is concluded that H. rotundifrons probably has a polygynous mating system in which males compete for soft females (female centered competition)
26

A handwriting analysis of the achievement of sinistrals in grades three through six

Jones, Marian P. January 1956 (has links)
Thesis (Ed.M.)--Boston University / The intention of this study is to examine the quality and quantitative achievements of two hundred seventy-nine left handed children located in the elementary schools of New England.
27

Development of Bioactive Peptidomimetics

She, Fengyu 01 October 2018 (has links)
Peptidomimetics are synthetic foldamers that expected more resistant to proteolytic degradation and enormous chemodiversity when compared with peptides. To date, the functional peptidomimetics such as β-peptides, peptoids, oligoureas, etc have been developed in many science fields. In order to explore the unnatural foldameric architectures, it’s necessary to discover the novel frameworks and molecular scaffolds. γ-AApeptides were reported to be a new class of peptidomimetics that showed its potential applications in drug discovery and chemical biology. However, a wide function and property of γ-AApeptides need to be further explored. To expand the potential application of γ-AApeptides in biochemistry, I have been focusing on the development of bioactive peptidomimetics, such as exploring the antibacterial activity of helical 1:1 α-sulfono-γ-AA heterogeneous peptides, developing the helical peptidomimetic as the inhibitor of the protein Ras_Raf interaction, identifying the protein/peptide ligands by the novel one-bead-two compound macrocyclic γ-AApeptide screening library, and elucidating the de novo dragon-boat-shaped synthetic foldamers.
28

Optical Studies ofNano-Structures in the Beetle<em>Cetonia Aurata</em><em></em>

Shamim, Rizwana January 2009 (has links)
<p> </p><p> </p><p> </p><p><p>The main</p><p>objective of this thesis is to study the polarization effects of the beetle <em>Cetonia aurata </em>using Mueller-matrix ellipsometry. The outer shell of the beetle consists of complex microstructures which control the polarization of the reflected light. It has metallic appearance which originates from helicoidal structures. When these microstructures are exposed to polarized or unpolarized light, only left-handed circularly polarized light is reflected. Moreover, the exo-skeleton of the beetle absorbs right-handed polarized light. Multichannel Mueller-matrix ellipsometer or dual rotating compensator ellipsometer, called RC2, from J.A.Woollam is used to measure the polarization caused by different parts of beetle’s body. The 16 Mueller matrix elements are measured in the spectral range 400-800 nm at multiple angles of incidencein the range 40<sup>0</sup>-70<sup>0</sup>. An Optical model is developed to help us understand the nature and type of microstructure which only reflects the green colour circularly polarized light. With the help of multiparametric modeling, we were able to find optical properties and structural parameters. The parameters are: the number of layers, the numbers of sub-layers, their thicknesses, and the orientation with respect to optical axes. This optical model describes the nanostructures which provide the reflection properties similar to the nanostructure found in the beetle <em>Cetonia aurata. </em>The model is also useful for analysis of the optical response data of different materials with multilayer structures.</p></p><p> </p>
29

Optical Studies ofNano-Structures in the BeetleCetonia Aurata

Shamim, Rizwana January 2009 (has links)
The main objective of this thesis is to study the polarization effects of the beetle Cetonia aurata using Mueller-matrix ellipsometry. The outer shell of the beetle consists of complex microstructures which control the polarization of the reflected light. It has metallic appearance which originates from helicoidal structures. When these microstructures are exposed to polarized or unpolarized light, only left-handed circularly polarized light is reflected. Moreover, the exo-skeleton of the beetle absorbs right-handed polarized light. Multichannel Mueller-matrix ellipsometer or dual rotating compensator ellipsometer, called RC2, from J.A.Woollam is used to measure the polarization caused by different parts of beetle’s body. The 16 Mueller matrix elements are measured in the spectral range 400-800 nm at multiple angles of incidencein the range 400-700. An Optical model is developed to help us understand the nature and type of microstructure which only reflects the green colour circularly polarized light. With the help of multiparametric modeling, we were able to find optical properties and structural parameters. The parameters are: the number of layers, the numbers of sub-layers, their thicknesses, and the orientation with respect to optical axes. This optical model describes the nanostructures which provide the reflection properties similar to the nanostructure found in the beetle Cetonia aurata. The model is also useful for analysis of the optical response data of different materials with multilayer structures.
30

Mating behaviour and the reproductive ecology of the big-handed crab, Heterozius rotundifrons A. Milne Edwards, 1867

Thompson, Glen Andrew January 1999 (has links)
The mating behaviour and reproductive ecology of the big-handed crab Heterozius rotundifrons was studied at Kaikoura between November 1997 and December 1998. H. rotundifrons was found at mean densities of 7.6 per m² (± 1.4) within the middle and low shore levels and varied little between seasons. The variance! mean ratio indicated that males and females aggregated within these shore levels. The sex ratio was significantly female biased during the majority of the year. Allometric growth rates indicated that males and females reached sexual maturity at 11 mm carapace width (CW). In males, spermatozoa production occurred between 9-9.99 mm CW. Ovigerous females were present every month except February. The first broods of the year were produced in March which coincides with a decrease in the female gonado-somatic index (GSI). These broods were incubated for approximately nine months whereas broods produced in August were incubated for only five months. Female brood production appeared to be cyclical, alternating between a winter incubation period and a summer incubation period. The completed cycle takes approximately three years with two broods produced during the cycle. Fecundity increased with female size but egg mortality was quite high (19%). Instantaneous mortality rate increased with increasing brood development. Females mate when recently moulted (soft-shelled). Although females moulted through out the year, in small numbers, there was a peak in female moulting during October and November. The operational sex ratio (OSR) was male biased during all months of the year. Females released an attractant prior to moulting which initiated pre-copulatory mate guarding by the male. Once the female moulted, copulation occurred approximately 6 h later. Copulation lasted for approximately 3 h and was followed by a period of post-copulatory mate guarding. Males increased the duration of post-copulatory mate guarding if another male was present. Large males out competed small males for receptive females. Males used their large cheliped to subdue competitors and to provide protection for the soft female. Mate guarding was shown to reduce cannibalism from other females. Spermatozoa are packaged in spermatophores within the vas deferens of males but are quickly dehisced within the spermathecae (ventral-type) of newly mated females. Last male to copulate probably achieves the highest level of paternity. Postcopulatory mate guarding by the male was found and ejaculates were found in discrete packets within the spermatheca. Sperm competition appeared to be important because large males displaced small males during copulation, males left when a female was still receptive and the females could retain sperm between moults. It is concluded that H. rotundifrons probably has a polygynous mating system in which males compete for soft females (female centered competition)

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