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Dissertations / Theses on the topic 'Polar'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 August 2024

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1

Müller, Marion. "Polare Stratosphärenwolken und mesoskalige Dynamik am Polarwirbelrand = Polar stratospheric clouds and mesoscale dynamics at the polar vortex edge /." Bremerhaven : Alfred-Wegener-Inst. für Polar- und Meeresforschung, 2001. http://www.gbv.de/dms/bs/toc/334030064.pdf.

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2

Khesin, Boris, Alexei Rosly, and rosly@heron itep ru. "Polar Homology." ESI preprints, 2000. ftp://ftp.esi.ac.at/pub/Preprints/esi941.ps.

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3

Trueblood, Jeffrey Allen. "Polar night." Thesis, University of Iowa, 2013. https://ir.uiowa.edu/etd/2649.

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For my thesis I plan on exploring the concepts and reasons that I make my art. I will talk about how I explore the night as my subject and the emotional response I hope to evoke with my work, and my influences and inspirations while exploring this topic. I will talk about how I try to show how in the modern world we try to take that darkness and drive it back with artificial lights intending to duplicate the world of daylight, but instead we create stages of normalcy in between the depths of the night allowing the individual imaginations of the viewer to dream into the darkness bringing their own experiences and emotions to the images and making an interactive viewing experience. By trying to recreate the mental state where our minds revert to the most primal instincts of fight or flight in the face of the unknown, despite our knowledge of what exists in the daylight, I try to reach a more primal work of art that goes beyond my early influences of the western Romantic art and show how these instincts still deeply affect us in our modern world.

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4

Newsham, David K. Sen Ayusman. "Palladium catalyzed copolymerizations of polar and non-polar monomers." [University Park, Pa.] : Pennsylvania State University, 2009. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-4528/index.html.

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5

Hanan, Faridah Hanim Ab. "Plasticizer transportation studies in polar and non-polar rubbers." Thesis, London Metropolitan University, 2001. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341733.

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6

SILVA, ELIZANDRA MARTINS. "NANOSCALE MECHANICAL DEFORMATION MECHANISMS OF POLAR AND NON-POLAR ZNO." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=24779@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO
Neste trabalho foi estudado o mecanismo de deformação de faces polares e não polares do óxido de zinco (ZnO), através da introdução de defeitos mecânicos por nanoindentação. A estrutura cristalina estável do ZnO é do tipo wurtzita, de forte caráter anisotrópico já observado em relação a propriedades como piezoeletricidade e polarização espontânea. O mecanismo de deformação mecânica desses sistemas ainda não está bem esclarecido e são de vital importância na otimização de dispositivos optoeletrônicos. A extensão dos defeitos para cada orientação do cristal foi analisada via microscopia eletrônica de transmissão e correlacionada com o movimento de planos basais {0001} de forma divergente, em faces não polares (1100) e (1120), e ao movimento de planos piramidais {1011} de forma convergente para faces polares (0001) e (0001). A extensão da deformação induzida abaixo da superfície foi avaliada, onde foi possível identificar a formação de discordâncias do tipo parafuso que se propagam através do sistema de escorregamento (1120)(0001), se propagando de forma altamente localizada abaixo da superfície. O início da deformação plástica em monocristais é marcado por eventos plásticos súbitos (pop-ins). Estes eventos foram identificados e analisados em função da força e da extensão da deformação gerada. A topografia e forma das impressões residuais foi analisada usando microscopia de força atômica. Os defeitos observados no plano superficial tenderam a se propagar em direções preferenciais num processo induzido pela formação de zonas de tensão em torno da indentação. A formação de zonas de tensão trativa em uma dada direção aumenta a mobilidade das discordâncias, enquanto zonas de tensão compressiva agem contribuindo para o travamento. Estas zonas foram identificadas e a magnitude desta tensão foi estimada via catodoluminescência. Observamos também que a face polar (0001) apresentou um comportamento reativo, onde defeitos localizados abaixo da superfície foram revelados através do processo de limpeza.
In this work, deformation mechanisms of polar and non-polar zinc oxide (ZnO) were studied by nanoindentation tests. The stable crystal structure of ZnO is the wurtzite with a strong anisotropic character observed in relation to the piezoelectricity and spontaneous polarization properties, for example. The mechanical deformation mechanisms of these sorts of materials are not yet fully understood, being of vital importance for optoelectronic devices optimization.For each ZnO crystallographic orientation, the induced defects damages were analyzed by transmission electron microscopy (TEM) and correlated with the slip of basal planes {0001} in the divergent directions for the both non-polar faces (1100) and (1120), as well as for the both polar faces (0001) and (0001). Screw perfect dislocations were identified by propagating through the slip system (1120)(0001). The beginning of plastic deformation in single crystals is marked by pop-ins events. Such events were identified and analyzed in function of the applied force and size. The residual impressions topography and shape were analyzed by atomic force microscopy (AFM). The observed defects on the surface were propagated in a preferred direction induced by stress components around the indentation. Tensile stress generation in a certain direction increases the dislocations mobility, while compressive stress contributes to pinning regions. Stress components were identified and their magnitudes were estimated by cathode luminescence method. The polar face (0001) showed a reactive behavior; some defects produced underneath the surface were revealed by samples cleaning process.

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7

Kullen, Anita. "Polar auroral arcs." Doctoral thesis, KTH, Alfvén Laboratory, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3562.

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8

Pajuelo, Eduardo María Marta. "Jorge Polar, educador." Pontificia Universidad Católica del Perú, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/114170.

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9

Liu, Ling. "Polar codes and polar lattices for efficient communication and source quantization." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/48001.

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In the past several decays, lattice codes played an important role in coding theory and information theory. Lattice codes with good performance in communication and source compression have attracted considerable interest. A typical method of constructing good lattice codes is to use existing linear codes. For instance, the famous Barnes-Wall lattices are generated by Reed-Muller (RM) codes, and more recently, the emerging low density Construction-A (LDA) lattices are resulted from low density parity check (LDPC) codes. In this thesis, we develop a new class of lattices, called polar lattices, based on polar codes. The invention of polar codes is considered to be one of the major breakthroughs in coding theory for the past ten years. We show that polar lattices provide explicit solutions for many interesting problems in information theory. For channel coding, we prove that polar lattices are capable of achieving the capacity of the additive white Gaussian noise (AWGN) channel. For the dual side, i.e., source compression, polar lattices can also achieve the rate-distortion bound for the independent and identically distributed (i.i.d.) Gaussian source. Moreover, a combining design of polar lattices for both channel coding and source coding gives us explicit solutions to the Gaussian version of the Wyner-Ziv and Gelfand-Pinsker problems. For physical layer security, we prove that polar lattices are able to approach the secrecy capacity of the Gaussian wiretap channel under the strong secrecy criterion. Two more applications of polar lattices are achieving the capacity of the i.i.d. fading channel and extracting the common information of two joint Gaussian sources. The explicit construction of polar lattices provides us better insights on the study of lattice coding. Many interesting problems of lattice coding, such as AWGN goodness, secrecy-goodness, lattice shaping, and lattice Gaussian distribution will be addressed from the perspective of polar lattices.

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10

Chang, Tse Yang. "Characterisation of polar (0001) and non-polar (11-20) ultraviolet nitride semiconductors." Thesis, University of Cambridge, 2012. https://www.repository.cam.ac.uk/handle/1810/242371.

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UV and deep-UV emitters based on AlGaN/AlN heterostructures are very inefficient due to the high lattice mismatch of these films with sapphire substrates, leading to high dislocation densities. This thesis describes the characterisation of the nanostructures of a range of UV structures, including c-plane (polar) AlGaN epilayers grown on AlN template, and nonpolar GaN/AlGaN MQWs grown on a-plane GaN template. The results are based primarily on transmission electron microscopy (TEM), cathodoluminescence in the scanning electron microscope (SEM-CL), high-resolution X-ray diffraction (HRXRD) and atomic force microscopy (AFM) measurements. The structural and optical properties of various types of defect were examined in the c-plane AlGaN epilayers. Strain analysis based on in-situ wafer curvature measurements was employed to describe the strain relief mechanisms for different AlGaN compositions and to correlate the strain to each type of defect observed in the epilayers. This is followed by the investigation of AlN template growth optimisation, based on the TMA pre-dose on sapphire method to enhance the quality and the surface morphology of the template further. The initial growth conditions were shown to be critical for the final AlN film morphology. A higher TMA pre-dose has been shown to enable a better Al coverage leading to a fully coalesced AlN film at 1 μm thickness. An atomically smooth surface of the template was achieved over a large 10 x 10 μm AFM scale. Finally, the investigation of UV emitters based on nonpolar crystal orientations is presented. The SiNx interlayer was able to reduce the threading dislocation density but was also found to generate voids with longer SiNx growth time. The relationship between voids, threading dislocations, inversion domain boundaries and their associated V-defects and the variation in MQW growth rate has been discussed in detail.

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11

Dihmes, Godoy Alfredo, Echevarría Diego Larach, and del Canto Fernando Yávar. "Valoración de La Polar." Tesis, Universidad de Chile, 2005. http://repositorio.uchile.cl/handle/2250/108353.

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El objetivo de este Seminario es encontrar los determinantes claves en el repunte que tuvo La Polar, desde su adquisición por parte del fondo de inversión Southern Cross, hasta llegar a situarse como la cuarta tienda por departamentos más grande de Chile, incluyendo su ingreso a la bolsa el año 2003, doblando su precio de colocación ($580) en menos de 2 años, y además obteniendo rentabilidades superiores a las de mercado en gran parte del periodo de transacción.. También se calculo el valor de mercado de la acción de La Polar, utilizando el método de Valoración de Flujo de Caja Libre, con un horizonte explícito de 5 años (2005 – 2009) y un horizonte implícito calculado a partir de los índices de la Industria Norteamericana. Los resultados fueron simulados con el programa sensibilizador de Parisi, el cual mediante una simulación de Monte Carlo, entrega el valor más probable de la acción ($1.230,98) y su rango de fluctuación ($684,8 y $1712,1), los cuales se acercan a los valores realmente pagados por la acción. Finalmente, podemos decir que la acción de La Polar se ha afirmado en el mercado, producto de una administración correcta, y sobre todo, por las altas expectativas de crecimiento futuras.

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12

El-Agamey, Ali Abdel Ghani. "Acylperoxyl radicals and their reactions with carotenoids in polar and non-polar solvents." Thesis, Keele University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252583.

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13

Emery, Robert Michael. "Investigation into the growth of non-polar and semi-polar InGaN quantum dots." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708911.

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14

Johnston, C. F. "Characterization of (11-20) non-polar and (11-22) semi-polar GaN epitaxial films." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.605657.

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This thesis describes the microstructural characterization (using transmission electron microscopy [TEM], high resolution X-ray diffraction [HRXRD] and atomic force microscopy [AFM]) of non-polar (11-20) and semi-polar (11-22) GaN epitaxial layers. They were grown under a range of conditions on sapphire by metal-organic vapour phase epitaxy (MOVPE). The majority of the dislocations were partial dislocations bounding BSFs. As a consequence, defects were confined to the c-plane. A 3D-2D growth transition (where 3D islands are grown initially, then coalesced) reduced the defect density of non-polar GaN. Optimised coalescence conditions (i.e. a V/III ratio of 50) produced smooth films with a low RMS roughness. The effect of a 3D-2D growth transition on semi-polar material was less clear, but the microstructure was similar to non-polar GaN, in that the majority of dislocations were partials bounding BSFs. Since the growth conditions for the semi-polar epilayers were not optimised, surfaces were rough. Quantum wells grown on these templates were found to follow the surface roughness resulting in large fluctuations in quantum well width (of a few nanometres) and subsequent broadening of peaks in the photoluminescence spectra. To reduce the defect density, epitaxial laterial overgrowth (ELOG), SiN_x interlayers and ScN interlayers were applied to non-polar and semi-polar films. ELOG was effective at reducing both BSF and dislocation density in both examples. Thick SiN_x interlayers in non-polar GaN reduced dislocation density by a factor of 500 and BSF density by a factor of 5, compared to the template. An 8.5 nm ScN interlayer in semi-polar GaN reduced the dislocation density by a factor of 200 and BSF density by a factor of 14.

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15

Zhang, Yuan. "STM Investigation of Electric Polar Molecular Self-Assembly and Artificial Electric Polar Molecular Rotors." Ohio University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1416927903.

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16

Sui, Yongqiang. "Toward polar 1,4-diphenylbutadiene materials." Diss., Columbia, Mo. : University of Missouri-Columbia, 2004. http://hdl.handle.net/10355/4099.

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Thesis (M.S.)--University of Missouri-Columbia, 2004.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 30, 2006). Includes bibliographical references.

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17

Persson, Marcus. "Surfactants at non-polar surfaces." Doctoral thesis, KTH, Chemistry, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3444.

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The aim of this thesis work was to investigate theadsorption of surfactants to different nonpolar interfaces.Particularly, the effects of the polar group and the nature ofthe hydrophobic interface were elucidated. The interfacialbehavior of the liquid-vapor interface was investigated bymeans of surface tension measurements. Here the effect of thepolar group and the hydrocarbon chain length was investigatedin a systematic manner. It was found that the shorter of thetwo chains examined, decyl, generated a larger surface pressurecontribution than the longer, dodecyl. Furthermore, the sugarbased surfactants behaved differently as compared to theethylene oxide based ones. The former could be modelled byassuming a hard disc behavior of the head group while thelatter displayed polymeric behavior. The influence of saltconcentration on the surface tension behavior of an ionicsurfactant, sodium dodecyl sulphate, was investigated. Theresult could be rationalized by employing the Gouy- Chapmanmodel to the polar region. Furthermore, mixtures of two sugarbased surfactants were investigated by surface tensionmeasurements and the adsorbed amount of the two components atthe interface atdifferent concentrations and fractions in thebulk were obtained by applying the Gibbs surface tensionequation. It was found that the molecule with the smaller headgroup adsorbed preferentially, and more so as the totalsurfactant concentration was increased. These findings could beexplained by considering the interactions generated by thedifferent head groups. The adsorption of sugar surfactants toan isolated hydrophobic surface was studied by means of wettingmeasurements and the behavior was similar to that at theliquid-vapor interface. Wetting isotherms were measured on twodifferent hydrophobic surfaces where the covalently attachedhydrophobic layers were in a crystalline and fluid state,respectively. The wetting results revealed that the sugarsurfactants anchored in the fluid hydrophobic layer. This had asignificant influence on the force profile. For example, at thecrystalline surface the surfactant monolayers were easilyremoved as the surface came into contact at relatively lowapplied loads. This was not the case when the hydrophobic layerwas in a fluid state. Here a significant fraction of thesurfactants remained between the surfaces. Disjoining pressureisotherms were measured using a sugar based surfactant thatwere thoroughly purified and compared to the as receivedsample. Even the purified sample showed a double-layer forcealthough lower as compared to the as received, one. Asignificant difference in foam stability was also observed.

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18

Sawade, Hans. "Polar schaltende Lyomesophasen diskotischer Flüssigkristalle." [S.l.] : [s.n.], 2002. http://edocs.tu-berlin.de/diss/2002/sawade_hans.pdf.

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19

Millien, Pierre. "On a polar factorization theorem." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/38915.

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We study the link between two different factorization theorems and their proofs : Brenier's Theorem which states that for any u ∈L^p(Ω), where Ω is a bounded domain in R ^d and 1 ≤ p ≤ ∞, u can be written as u=∇ ɸ ο s where ɸ is a convex function, and s a measure preserving transformation, and on the other hand Ghoussoub and Moameni's theorem which states that for any u ∈ L∞ (Ω), u(x) = ∇₁H(S(x),x), where H is a convex concave anti-symmetric function, and S is a measure preserving involution. In a second time we prove that Ghoussoub and Moameni's theorem is true in L², and find the decomposition for particular example : u(x) = |x-1/2|.

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20

Choi, Kwansik. "Molecular interactions in polar solvents." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/17851.

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21

Rust, Arlene Elizabeth. "Thermohaline convection in polar seawater." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321658.

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22

Soria-Alvarez, Carmen. "Synthetic applications of polar metallocenes." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614902.

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23

Thesling, Bill. "Digital Cross-Polar Interference Canceller." International Foundation for Telemetering, 2010. http://hdl.handle.net/10150/604302.

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ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California
Dual-polarized data transmission promises to double the system capacity by transmitting independent signals simultaneously on both polarizations in the same channel. However, the polarization orthogonality of the propagation field can not always be perfectly preserved in various environments. Also the antenna and waveguide networks may not be able to achieve absolute polarization isolation. Therefore cross-polarization interference becomes a severe source of performance degradation in dual-polar systems. This paper presents an all-digital design of the cross-polarization interference canceller (XPIC or CPIC). This canceller is designed to remove the cross-polar interference so that comparable performance to single-polar system can be achieved for each polarization. Specifically, this digital design aims for • Mitigating the cross-polarization interference caused primarily by antenna orientation. (Delay between the signals from both polarizations is considered insignificant.) • Can operate with time varying cross-polar interference varying at rates of 2-3 Hz and beyond. • Initial isolation can be as low as 10 dB. • Is well suited to an all digital modem where clocking from the A/D is independent of symbol timing recovery clocks.

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24

Zhou, Linghui. "Polar Codes for Identification Systems." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-232176.

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Identication systems are ubiquitous, for example, biometric identication systemswith ngerprints and Face IDs, etc. Basically, the identication problemconsists of two steps. The enrollment phase where the user's data are captured,compressed and stored, for example taking the ngerprint or capturing some importantfeatures of your face. In the identication phase, an observation, yourngerprint or your face, is compared with the stored information in the databaseto provide an armative answer. Since the system involves many users, bothstoring and searching for the correct user is challenging.This project aims to implement compression and identication algorithms forthe high dimensional identication system which includes M users. Polar codesare employed to be the main toolbox. Firstly, we implement polar codes for thesource compression and then design corresponding identication mappings. Thesource compression can be seen as the channel decoding of polar codes. In theidentication phase, the observation can be seen as the side information, so wewill consider using Wyner-Ziv coding for polar codes to reconstruct and identify.In the next step, we will implement polar codes for two-layer Wyner-Zivcoding for identication systems. This will enable us to store the compresseddata in separate databases and do the reconstruction in two stages. With theenrollment mapping and identication mapping implemented, we will evaluatethe performance of the designed identication systems, such as identicationerror rate and complexity. Some possible further directions would be to implementmore advanced algorithms such as simplied or fast simplied successivecancellation encoding in source coding and universal decoding in identication.
Identieringssystem frekommer verallt, till exempel, biometriska identieringssystemmed ngeravtryck och ansiktsigenknning, etc. Fundamentalt kan problemetbrytas ned i tv faser. Registreringsfasen dr data om anvndaren insamlas, komprimerasoch lagras, till exempel att ta ngeravtryck eller nna viktiga ansiktsdetaljer.I identieringsfasen, jmfrs en observation, ditt ngeravtryck elleransikte, med information som lagrats tidigare fr att ge ett positivt svar. Eftersomsystemet hanterar mnga anvndare r bde lagring och skning efter den rttaanvndaren utmanande.Syftet med detta projekt r att designa och implementera eektiva komprimeringsochidentieringsalgoritmer fr det hgdimensionella Identieringssystemet medM anvndare. Polar codes anvnds som det huvudsakliga verktyget. Frst implementerarvi polar codes fr eektiv kllkomprimering och designar sedan motsvarandeidentieringskartlggning. Kllkomprimering kan ses som kanalavkodningen avpolar codes och I identieringsfasen kan observationen ses som sido-informationen,s vi vervger att anvnda Wyner-Ziv kodning fr polar codes fr att rekonstrueraoch identiera. I nsta steg implementerar vi polar codes fr skra Wyner-Zivproblem. Detta tillter oss att spara komprimerad data i separata databaser ochterskapa med tv steg. Med registreringskarlggning och identieringskartlggningimplementerade utvrderar vi prestandan av de designade identieringssystemenmed metoder som felfrekvens av identieringar och berkningskomplexitet.

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25

Burrows, Susannah. "Polar measurements of mesospheric CO." Oberlin College Honors Theses / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=oberlin1119041096.

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26

Quezada, María Paz. "Valoración de La Polar S.A." Tesis, Universidad de Chile, 2016. http://repositorio.uchile.cl/handle/2250/145727.

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TESIS PARA OPTAR AL GRADO DE MAGÍSTER EN FINANZAS
En el presente trabajo se desarrolló una valoración económica y financiera de Empresas La Polar, utilizando como método Flujos de Caja Descontados, esta valoración fue realizada utilizando la información financiera publicada por la empresa hasta el 30 de Septiembre de 2013 en sus memorias y en la Superintendencia de Valores y Seguros. Se realizó un análisis global de la empresa, tanto de su historia, como ha sido su desarrollo, a que segmento está enfocado, como financia sus proyectos, todos estos factores que nos permitieron realizar proyecciones financieras las cuales utilizando como metodología Flujo de Caja Descontados obtuvimos como resultado el precio de la acción. Para realizar las proyecciones financieras necesarias, es importante recaudar información financiera de Empresa La Polar y de la industria en la cual está inserta, para poder determinar cómo es el funcionamiento de esta, como le afectan la variables económicas y así poder construir supuestos consecuentes y conservadores, de modo de que nuestros cálculos sean lo más cercanos a la realidad. El objetivo de este trabajo es mostrar de una manera sencilla cómo se realiza en la práctica un análisis financiero de una empresa, que variables son necesarias tener en consideración, de donde puedes obtener la infurción necesaria para realizar los diferentes cálculos y posteriormente las proyecciones. La Valoración de Empresas, es considerada una buena herramienta en la toma de decisiones de inversión, ya que a través de esto puedes determinar si está en un precio de la acción es mayor o menor a su precio histórico, si es conveniente realizar compras o ventas de dicha acción, nos permite tener una visión basada en fundamentos financieros.

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27

Dyck, Markus Guido. "Effects of tundra vehicle activity on polar bears ( Ursus maritimus) at Churchill, Manitoba." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63946.pdf.

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28

Nowack, Rüdiger Jens. "Neutral nickel and palladium complexes as catalysts in copolymerizations of polar and non-polar monomers." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:289-vts-63659.

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29

Gunkel, Felix [Verfasser]. "The role of defects at functional interfaces between polar and non-polar perovskite oxides / Felix Gunkel." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2013. http://d-nb.info/1044492325/34.

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30

Bennett, Megan. "Energy Transfer Dynamics in Collisions of Polar and Non-polar Gases with Functionalized Self-Assembled Monolayers." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/33229.

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Molecular beam scattering experiments are used to investigate the extent of thermal accommodation of Ne, CD4, ND3, and D2O in collisions with long chain CH3, NH2, and OH terminated self-assembled monolayers (SAMs) on gold. Surface rigidity, internal degrees of freedom of the impinging gas, and potential energy surface well depths have been explored as a way to predict the outcome of a gas-surface collision. Ne is used to assess the mechanical rigidity of the SAMs. The order of rigidity is CH3 < NH2 ~ OH. The NH2 and OH terminated SAMs are more rigid due to the intermolecular hydrogen bonding structure at the gas-surface interface. Despite the hydrogen bonding nature of the NH2 and OH terminated SAMs CD4, ND3, and D2O are extensively thermally accommodated on the surfaces, therefore surface rigidity is no solely responsible for energy transfer dynamics. It was found that the number of degrees of freedom do not predict how extensively a gas will thermally accommodate on a surface capable of hydrogen bonding. A qualitative correlation between increasing potential energy well depths and the extent of thermal accommodation has been established as a result of these scattering experiments.
Master of Science

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Gong, Yipin. "MOCVD growth and optical investigation of III-nitride materials including non-polar and semi-polar GaN." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/4991/.

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This thesis focuses on the growth of high quality III-nitride materials by MOCVD along both c-direction and non-polar a-direction. High temperature AlN buffer layer is introduced, which can effectively reduce the dislocation density of the overlying layer. Stimulated emission at 340nm has been obtained by such AlN buffer techniques, which mechanism is understood by studying the strain relaxation in the QW structure with RSM measurements. A non-polar overgrowth approach has also been established for the growth of non-polar GaN, leading to an impressive improvement in the crystalline quality. Meanwhile, optical investigation on c-plane InGaN/GaN MQW nanorod structures has been performed, demonstrating an significantly enhanced photoluminescence emission. It has been concluded that the enhancement is due to the reduction on quantum confined Stark effect caused by strain relaxation in the MQW structure.

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32

Drinkwater, Mark Roland. "Radar altimetric studies of polar ice." Thesis, University of Cambridge, 1987. https://www.repository.cam.ac.uk/handle/1810/268053.

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Active microwave sensors are known to provide valuable information regarding snow and ice surfaces in the polar regions, where darkness and cloud cover prevail. Here, data collected in the Arctic by a Ku-band microwave radar altimeter, designed and constructed in the UK, are analysed. The two main components of this study comprise data gathered in the East Greenland Sea marginal ice zone and over two Svalbard ice caps. A systematic treatment is made of the electromagnetic properties of snow and ice at 13.81 GHz, and the differences between various polar surface media are highlighted. Theoretical and empirical models are presented which enable calculation of the relevant dielectric and scattering properties of snow and ice layers. Parametric studies are undertaken to give insight into the range of scattering conditions likely to be encountered by a radar altimeter in the regions investigated. Examples of altimetric data and results of their analysis are presented, demonstrating the effects of different ice types and terrain upon incident altimeter pulses. Waveforms are characterised by their shape, and certain forms are linked with particular physical properties of the surface. To this a variety of supporting information is added in order to verify and validate interpretations of these results. Algorithms are proposed which enable geophysical information to be derived from altimetric data.

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33

McCallum, Adrian Bruce. "Cone penetration testing in polar snow." Thesis, University of Cambridge, 2012. https://www.repository.cam.ac.uk/handle/1810/244073.

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Innovative Cone Penetration Testing (CPT) using adapted commercial CPT equipment was conducted in Antarctica in early 2010 in an attempt to assess the strength of polar snow; additionally, application of CPT data was considered, particularly in estimating surface bearing capacity. Almost 100 CPT tests were carried out and both qualitative and quantitative analysis of data was undertaken. Additional supporting testing in- cluded snow density assessment, snow strength assessment, extrapolation of CPT data via Ground Penetrating Radar (GPR) and preliminary mini-cone penetrometer testing in Greenland. Analysis of results revealed that assessing the strength of polar snow via CPT is affected by numerous factors including penetration rate, cone size/shape and snow material properties, particularly compaction of the snow undergoing penetration. A density-dependant relationship between CPT resistance and snow shear strength was established, and methods for estimating surface bearing capacity directly from CPT in homogeneous and layered polar snow were proposed. This work applied existing technology in a new material and shows that CPT can be used efficiently in polar environs to provide estimates of snow shear strength and surface bearing capacity, to depths of 10 m or more.

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34

Margerum, Michael Robert. "Equations of state for polar fluids." Thesis, University of Ottawa (Canada), 1989. http://hdl.handle.net/10393/5863.

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35

Zhou, Wei Hua. "Spectral approximation by the polar transformation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq25988.pdf.

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36

Welch, C. S. "Servicing polar platforms using electric propulsion." Thesis, Cranfield University, 1992. http://hdl.handle.net/1826/3435.

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The future of space development has been examined in the context of the infrastructure necessary support it. It is concluded that the selection of propulsion systems for in-orbit transportation requires the development of general computer codes capable of simulating the use of a wide range of propulsion systems on near-Earth missions. It is also concluded that, even if limited infrastructural development occurs, polar orbiting spacecraft will be an important feature of future space activities. Replacing current single-use polar spacecraft with extended-life serviceable platforms is attractive. However, the very limited manned access polar orbits in the mid-term future suggests that such platforms will only be possible if remote telerobotic/autonomous servicing can be carried out. To this extent polar platforms are considered to provide a useful driver and first testbed for the development of technologies designed to extend human capability in those regimes where direct mediation is not possible. Options for such remote servicing are examined, the concept of performing nodal transfers by enhanced differential nodal drift is introduced and the application of electric propulsion to this discussed. Low-thrust orbital manoeuvres are analyzed in this context and the conditions for optimum nodal transfer defined. Particular service vehicle configurations are then defined against a projected infrastructure and baseline polar platform constellation. A model for the service vehicle is defined and its performance investigated using a number of electric propulsion systems. Simulations of transfer manoeuvres; have been carried out and the effects and relative importance of the various orbit perturbations identified. It is concluded that a service vehicle propelled by a Xenon ion system offers the capability required and two final configurations are identified characterising different servicing mission upload schemes.

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37

Day-Williams, Michaela Joanne. "Polar flagellum glycosylation in aeromonas caviae." Thesis, University of Sheffield, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515262.

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38

Tabor, Richard F. "Surfactant kinetics in non-polar solvents." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.508096.

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39

Russell, B. C. "The polar surfaces of strontium titanate." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.497089.

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40

Homam, Mariyam Jamilah. "Radiowave propagation in the polar ionosphere." Thesis, University of Leicester, 2012. http://hdl.handle.net/2381/10812.

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A dual-frequency GPS receiver, GSV4004B, has been installed at Alert, Canada since May 2008 to study the ionospheric variability at a high-latitude location. This Ionospheric Scintillation and TEC Monitor (GISTM) receiver is able to measure amplitude and phase scintillation, and also Total Electron Content (TEC). In addition, a High Frequency (HF) link has been established from Qaanaaq to Svalbard since March 2009 to study the channel characteristics, including Doppler spreads. This study covers from end of May 2008 to February 2011 where it was mostly during the minimum state of solar activity. During the period of where both GISTM and HF data were available (i.e. March 2009-July 2010), data from both links are compared to see any relation between TEC variations and scintillation effects and also Doppler spreads. Data from the GISTM receivers at Svalbard were also utilised. Winter months expectedly show lower mean vertical TEC (VTEC) than in other months. Higher mean VTEC was observed in 2010 that could be related to the increase of solar activity. In 2010, both small and large patches of moderate-high intensity were found to be more than twice as common in February and March than in other months. The difference in the occurrences of small patches between months of the same year was about 1-2% (for low intensity patches) and 1-10% (moderate-high intensity). This difference increased to 1-4% (low intensity) and 1-12% (moderate-high intensity) for large patches. UT dependence can be seen where ~80 large and ~300 small patches were identified ~1000 to 2000 UT from June to October in both 2008 and 2009, and they doubled in 2010. Amplitude scintillations index, S4 were very low where at least ~99% were between 0 and 0.1, which is insignificant. Meanwhile, phase scintillations index, σφ were from 0 to 0.1 rad for at least 93% of the time. The relationship of TEC fluctuations/increase and phase scintillations is complex. There are few events where phase scintillations occurred simultaneously with slant TEC increases, but this is not frequent. The magnitude of the irregularities was generally independent of geomagnetic indices, Interplanetary Magnetic Field (IMF) components, and local magnetic fields at Eureka and Resolute Bay. Monthly upper decile of Doppler spreads generally varied from 1 to 5.5 Hz. High upper decile normally occurred from around September/October to March, from ~0000 to 1700 UT on 6.95 and 8.01 MHz. The hourly upper decile reached up to 7-8.5 Hz (6.95 MHz) and 7-9.5 Hz (8.01 MHz). Upper decile on these frequencies was mostly 0.5-4.5 Hz larger in October 2010-February 2011 than in the same months of the previous year which possibly related to the increase in solar activity. However, Doppler spreads were generally independent of independent of geomagnetic indices, IMF components, and local magnetic fields. The relation between the irregularities observed via transionospheric link and HF link is also complex. Large TEC fluctuations/increases and/or phase scintillations observed on satellite(s) close to HF midpoint may correspond to either small or large Doppler spreads.

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41

Hill, E. M. H. "The foliar penetration of polar compounds." Thesis, Liverpool John Moores University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379437.

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42

Gregory, Philip David. "Coherent control of ultracold polar molecules." Thesis, Durham University, 2018. http://etheses.dur.ac.uk/12484/.

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This thesis presents the development of a toolbox for the coherent control of ultracold polar molecules. Such systems of molecules promise the creation of long-lived, highly dipolar quantum gases with applications spanning the fields of quantum state controlled chemistry, quantum information, quantum simulation, and precision measurement. However, the addition of vibrational and rotational degrees of freedom leads to molecular systems being significantly more complex than their widely used atomic counterparts. In this work we demonstrate full control of the quantum state down to the hyperfine level of an optically trapped sample of ultracold bosonic 87Rb133 Cs molecules, and exploit that control to begin an investigation into the collision processes which take place in an ultracold molecular gas. We create a sample of up to ∼ 4000 optically trapped molecules in their rovibronic and hyperfine ground state. We characterise the molecules by measuring their temperature, binding energy, and molecule-frame electric dipole moment. We perform spectroscopy of the first rotationally excited state with hyperfine state resolution using microwaves to determine accurate values of rotational and hyperfine coupling constants. We use coherent π pulses to perform complete transfer population between selected hyperfine levels of the ground, first-excited, and second-excited rotational states. We investigate the effect of the off-resonant light of our optical dipole trap on the rotational and hyperfine structure of the molecules. Through a combination of high-resolution microwave spectroscopy and parametric heating measurements, we characterise the polarisability of the 87Rb133Cs molecule. We demonstrate that coupling between neighbouring hyperfine states manifests in rich structure with many avoided crossings in any rotational state other than the ground state. This coupling may be tuned by rotating the polarisation of the linearly polarised trapping light. Finally, we study the lifetime of polar bosonic 87Rb133Cs molecules in our 3D optical dipole trap. We examine the lifetime of the molecules as a function of dipole trap intensity, magnetic field, and hyperfine and rotational state. Despite the chemical stability of the 87Rb133 Cs molecule, we observe lifetimes of ∼1 s corresponding to 2-body decay rates close to the universal limit.

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43

Riddolls, Ryan James 1974. "Structure of the polar electrojet antenna." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/16945.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.
Includes bibliographical references (p. 153-156).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Field experiments were performed in Gakona, Alaska in August and November 2002. The ionospheric conductivity was periodically perturbed using amplitude-modulated radiation from the HAARP HF transmitter (1 MW power, 14 dB gain, 3.3-5.8 MHz carrier, 0.1-40 kHz modulation). The conductivity perturbations lead to perturbations to the natural flow of electrojet current in the lower ionosphere, resulting in ELF/VLF radiation at the modulation frequency. Measurements of the radiation, along with analytic and numerical models, suggest that a vertical loop with a scale size of 10 km is the dominant current structure excited during the experiments.
by Ryan James Riddolls.
Ph.D.

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44

Hayat, Hassan. "Polar vortex and generation fuel diversity." Kansas State University, 2015. http://hdl.handle.net/2097/19094.

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Master of Science
Department of Electrical and Computer Engineering
Anil Pahwa
The unusual weather events during the polar vortex of 2014 illuminated the needs for fuel diversity for power generation in order to allow reliable operation of the electricity grid. A system wide reliability assessment for winter months should be undertaken in addition to the summer months to ensure reliable operation of the electricity grid throughout the year. Severe weather conditions that lead to equipment malfunction during the polar vortex should be thoroughly investigated and remediations to ensure satisfactory future performance of the grid must be undertaken. Environmentally unfriendly emissions from power plants must be minimized but diversity of generation fuel must be maintained. Future energy policies must be formulated with consideration that approximately 14 GW of coal generation in Pennsylvania Jersey Maryland Regional Transmission Organization’s control area available during the polar vortex will be retired by 2015 and replaced with plants that utilize fuel types other than coal.

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45

Nielsdóttir, Maria Chun. "Iron biogeochemistry in (sub-) Polar waters." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/145859/.

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Iron represents an important control on primary production in high nutrient low chlorophyll (HNLC) regimes and has received considerably attention during the last two decades. This work has focussed on the biogeochemistry of iron in two oceanic environments; the high latitude North Atlantic and the Scotia Sea in the Southern Ocean. The mechanisms of iron supply and the biological response of resident phytoplankton communities to iron were addressed in both study areas. Two cruises to the high latitude North Atlantic Ocean (>55 °N) during late July-early September 2007 indicated that nitrate concentrations of 2 to 5 M persisted in the surface waters. The concentration of dissolved iron (dFe) in the surface waters was very low, with an average of 0.093 (<0.010-0.218, n=43) nM, and in situ chlorophyll concentrations were < 0.5 mg m-3. In vitro iron addition experiments demonstrated that the addition of iron increased photosynthetic efficiencies (Fv/Fm) and resulted in enhanced chlorophyll in treatments amended with iron when compared to controls. A number of phytoplankton taxa, including the coccolithophore Emiliania huxleyi, were observed to increase their net growth rates following iron addition. These results provide strong evidence that iron limitation within the post spring bloom phytoplankton community contributes to the observed residual macronutrient pool during summer. Low atmospheric iron supply and suboptimal Fe:N ratios in winter overturned deep water are suggested as proximal causes for this seasonal High Nutrient Low Chlorophyll (HNLC) condition, which represents an inefficiency of the biological (soft tissue) carbon pump. Large areas of the Southern Ocean are characterised as HNLC. Satellite chlorophyll data indicate that phytoplankton blooms occur in vicinity to Southern Ocean Island systems. The bloom associated with South Georgia has the largest spatial extent and duration (16-20 weeks). Detailed measurements were made on austral spring and summer cruises to the Scotia Sea during November – early December 2006 and January – February 2008. This work presents the first comprehensive study of seasonal variations in phytoplankton biomass and iron availability in the Scotia Sea. The drawdown of nitrate between the two seasons in the South Georgia bloom was 16 M indicative of substantial new production. Surface water concentrations of dissolved iron (dFe) were slightly higher during summer than spring (0.31 nM compared to 0.20 nM, with P>0.05). We suggest that the South Georgia bloom is sustained by a continuous benthic supply of iron from the South Georgia shelf. In addition, enhanced dFe (0.34 nM) was observed in a cryptophyte dominated bloom in the southern Scotia Sea in the vicinity of South Orkney Islands. The difference in the community composition between the two natural occurring blooms highlight that Southern Ocean island systems have individual characteristics and should be viewed independently.

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46

Peng, Liz Shihching. "p5.Polar - Programming For Geometric Patterns." Digital WPI, 2020. https://digitalcommons.wpi.edu/etd-theses/1353.

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Traditional teaching methods are often passive and do not interactively engage students, and this is even more challenging when teaching programming to beginners. In recent years, tech companies such as Google, and academic institutions like MIT, have introduced online learning environments to schools for teaching programming. Most of these learning environments are web-based, interactive, and provide visual feedback. Our project follows these trends and builds on p5.js, a JavaScript library that provides software sketching features and rapid visual feedback to reduce the barrier for learning programming languages. We designed and implemented a new library for drawing geometric patterns using polar coordinate systems, p5.Polar. We then developed a game that incrementally teaches our library to players, and evaluated it with an online user study.

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47

Akyol, Fatih. "N-Polar III-Nitride Optoelectronic Devices." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1307562902.

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48

Türk, Serhat, and Kristoffer Müller. "Kinetic Art Table : Polar sand plotter." Thesis, KTH, Mekatronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-296307.

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CNC machines are used with plenty of different implementations, one of which is in this project where a polar CNC machine was used to draw mesmerizing patterns on a table with fine sand. This construction read G-code and converted it to polar coordinates. The capabilities of what the plotter could draw were tested, everything from ODE plots to custom-made patterns and drawings with the help of Sandify. Although the patterns were drawn properly with small errors the ODE was too difficult to draw because it required a smaller magnetic ball and an even more precise system than what was used. This machine also generated noise at roughly 33 dB when it was in use.
CNC-maskiner används med massor av olika implementationer, en av dem är i det här projektet där en polar CNC maskin användes för att rita fascinerande mönster på ett bord fylld med fin sand. Denna konstruktion läste in G-kod och konverterade det till polära koordinater. Förmågan av vad maskinen kunde rita testades, allt från ODE grafer till specialtillverkade mönster och ritningar med hjälp av Sandify. Aven om de olika mönstren ritades ordentligt men med mindre små fel var ODE för svårt att rita på grund av att det krävde en mindre magnetisk kula och ännu mer noggrannhet jämfört med detta system. Denna maskin alstrade också ljud på cirka 33 dB under användning.

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49

Oyama, Toshiyuki. "Synthesis of Novel Aprotic Polar Polymers." Kyoto University, 1999. http://hdl.handle.net/2433/181827.

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50

Sritana-Anant, Yongsak. "Polar-pi interactions : the model studies /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p9970663.

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