3D Ionospheric Effects on HF Propagation and Heating

The thesis uses a three-dimensional, first-principles model of the ionosphere in combination with High Frequency (HF) raytracing model to address key topics related to the physics of HF propagation and artificial ionospheric heating. In particular: 1. Explores the effect of the ubiquitous electron density gradients caused by Medium Scale Traveling Ionospheric Disturbances (MSTIDs) on high-angle of incidence HF radio wave propagation. Previous studies neglected the all-important presence of horizontal gradients in both the cross- and down-range directions, which refract the HF waves, significantly changing their path through the ionosphere. The physics-based ionosphere model SAMI3/ESF is used to generate a self-consistently evolving MSTID that allows for the examination of the spatio-temporal progression of the HF radio waves in the ionosphere. 2. Tests the potential and determines engineering requirements for ground- based high power HF heaters to trigger and control the evolution of Equatorial Spread F (ESF). Interference from ESF on radio wave propagation through the ionosphere remains a critical issue on HF systems reliability. Artificial HF heating has been shown to create plasma density cavities in the ionosphere similar to those that may trigger ESF bubbles. The work explores whether HF heating may trigger or control ESF bubbles. 3. Uses the combined ionosphere and HF raytracing models to create the first self-consistent HF Heating model. This model is utilized to simulate results from an Arecibo experiment and to provide understanding of the physical mechanism behind observed phenomena. The insights gained provide engineering guidance for new artificial heaters that are being built for use in low to middle latitude regions. In accomplishing the above topics: (i) I generated a model MSTID using the SAMI3/ESF code, and used a raytrace model to examine the effects of the MSTID gradients on radio wave propagation observables; (ii) I implemented a three- dimensional HF heating model in SAMI3/ESF and used the model to determine whether HF heating could artificially generate an ESF bubble; (iii) I created the first self-consistent model for artificial HF heating using the SAMI3/ESF ionosphere model and the MoJo raytrace model and ran a series of simulations that successfully modeled the results of early artificial heating experiments at Arecibo.

Defibrillator

Defibrillator is a 16’41” musical work for solo performer, laptop computer and electric guitar. The electric guitar is processed in real-time by digital signal processing network in software, with gestural control provided by a foot-operated pedal board. --------- The work is informed by a range of ideas from the genres of electroacoustic music, western art music, popular music and cinematic sound. It seeks to fluidly cross and hybridise musical practices from these diverse sonic traditions and to develop a compositional language that draws upon multiple genres, but at the same time resists the ability to be located within a singular genre. Musical structures and sonic markers which form genre are ruptured at strategic levels of the musical structure in order to allow for a cross flow of concepts between genres. The process of rupture is facilitated by the practical implementation of music and sound reception theories into the compositional process. -------- The piece exhibits the by-products of a composer born into a media saturated environment, drawing on a range of musical and sonic traditions, actively seeking to explore the liminal space in between these traditions. The project stems from the author's research interests in locating points of connection between traditions of experimentation in diverse musical and sonic traditions arising from the broad uptake of media technologies in the early 20th century.

Notions of Nation : A Critical Discursive Psychology perspective on the Isle of Man

At the the heart of this study can be seen the dual concern of how the nation is represented as a categorical entity and how this is put to use in everyday social interactions.This can be seen as a reaction to the general approach to categorisation and identity functions that tend to be reified and essentialized within the social sciences. The empirical focus of this study is the Isle of Man, a crown dependency situated geographically central within the British Isles while remaining political outside the United Kingdom. The choice of this site was chosen explicitly as ‘notions of nation’ expressed on the island can be seen as being contested and ephemerally unstable. To get at these ‘notions of nation’ is was necessary to choose specific theoretical tools that were able to capture the wider cultural and representational domain while being capable of addressing the nuanced and functional aspects of interaction. As such, the main theoretical perspective used within this study was that of critical discursive psychology which incorporates the specific theoretical tools interpretative repertoires, ideological dilemmas and subject positions. To supplement these tools, a discursive approach to place was taken in tandem to address the form and function of place attached to nationhood. Two methods of data collection were utilized, that of computer mediated communication and acquaintance interviews. From the data a number of interpretative repertoires were proposed, namely being, essential rights, economic worth, heritage claims, conflict orientation, people-as-nation and place-as-nation. Attached to such interpretative repertoires were the ideological dilemmas region vs. country, people vs. place and individualism vs. collectivism. The subject positions found are much more difficult to condense, but the most significant ones were gender, age and parentage. The final focus of the study, that of place, was shown to be more than just an unreflected on ‘container’ of people but was significant in terms of the rhetorical construction of such places for how people saw themselves and the discursive function of the particular interaction. As such, certain forms of place construction included size, community, temporal, economic, safety, political and recognition. A number of conclusions were drawn from the above which included, that when looking at nation categories we should take into account the specific meanings that people attach to such concepts and to be aware of the particular uses they are put to in interaction. Also, that it is impossible to separate concepts neatly, but it is necessary to be aware of the intersection where concepts cross, and clash, when looking at nationhood.

A characteristic based numerical method with tracking for nonlinear wave equations

Many physical problems can be modeled by scalar, first-order, nonlinear, hyperbolic, partial differential equations (PDEs). The solutions to these PDEs often contain shock and rarefaction waves, where the solution becomes discontinuous or has a discontinuous derivative. One can encounter difficulties using traditional finite difference methods to solve these equations. In this paper, we introduce a numerical method for solving first-order scalar wave equations. The method involves solving ordinary differential equations (ODEs) to advance the solution along the characteristics and to propagate the characteristics in time. Shocks are created when characteristics cross, and the shocks are then propagated by applying analytical jump conditions. New characteristics are inserted in spreading rarefaction fans. New characteristics are also inserted when values on adjacent characteristics lie on opposite sides of an inflection point of a nonconvex flux function, Solutions along characteristics are propagated using a standard fourth-order Runge-Kutta ODE solver. Shocks waves are kept perfectly sharp. In addition, shock locations and velocities are determined without analyzing smeared profiles or taking numerical derivatives. In order to test the numerical method, we study analytically a particular class of nonlinear hyperbolic PDEs, deriving closed form solutions for certain special initial data. We also find bounded, smooth, self-similar solutions using group theoretic methods. The numerical method is validated against these analytical results. In addition, we compare the errors in our method with those using the Lax-Wendroff method for both convex and nonconvex flux functions. Finally, we apply the method to solve a PDE with a convex flux function describing the development of a thin liquid film on a horizontally rotating disk and a PDE with a nonconvex flux function, arising in a problem concerning flow in an underground reservoir.

El imaginario de la luz en la mística cortés de Matilde de Magdeburgo : continuidad y transformación de la herencia hildegardiana en el siglo XIII

El artículo se propone desarrollar la continuidad y proyección de la estética de Hildegarda de Bingen en el siglo XIII a través del estudio del imaginario de la luz en la obra La luz fluyente de la divinidad de Matilde de Magdeburgo. El paso de una estética espacial de lo ígneo hacia una estética temporal de lo líquido se corresponde con la transformación del paradigma sacral feudal en el de la mística cortés, a cuyos tópicos responde la obra de esta última. La figura de Matilde, que se vuelve una con su obra, describe una curva que va desde la cosmología simbólica, por la mística cortés del Amor, hacia la mística del abismo y del desierto que brota del grito inarticulado de la cruz y que proyecta su influencia hacia el siglo XIV. En el dinamismo de la simbólica del agua y de las imágenes nupciales que acompañan a esta luz fluyente del amor, Matilde ha dejado trazadas sendas para pensar, en lenguaje estético, la experiencia de Dios en nuestro siglo XXI.

Fe, cristianismo y humildad: núcleos teologales de la pastoral popular del padre Rafael Tello

Resumen: Sin pretender “espiritualizar” la teología del padre Rafael Tello, este artículo ofrece algunas de las vertientes en las que abreva la espiritualidad de la pastoral popular de la que el teólogo argentino es uno de sus más originales representantes. Indagaremos en ciertos núcleos teologales y teológicos que nos permitirán registrar una continuidad entre teología y vida, al tiempo que nos dejarán en el umbral de una propuesta evangelizadora que no es posible comprender sin esta manera de vivir la fe cristiana. De la mano de figuras tradicionales de la mística y de la teología como san Juan de la Cruz y santo Tomás de Aquino, el padre Tello nos propone recrear la vivencia del evangelio para los tiempos actuales.

Artes de Exu: intervenções artísticas e representações afro-brasileiras no Rio de Janeiro: Tridente de Ni e Exu dos Ventos

Artes de Exu trata os objetos de arte não só pelos aspectos artísticos e sociológicos, mas também pelos aspectos que ligam as obras a Exu, além do enunciado. Como coisa contida na concepção, na execução e imbricada na própria história da obra. As obras escolhidas são: Tridente de NI (2006) de Alexandre Vogler e Exu dos Ventos (1992), de Mario Cravo Júnior. As obras contêm conflitos que envolvem a mídia, religiosos e políticos. A partir de pesquisas etnográficas é feita uma análise dos olhares que se cruzam na construção dos sentidos na disputa pelo espaço simbólico, considerando ainda o trânsito percorrido pelas obras entre a oficina, o espaço de exposição e a rua. Pertence ainda ao corpo das análises as referências na mídia impressa, forma de veiculação das imagens, apropriações e discursos. As artes de Exu se evidenciam no desenrolar dessas tramas, conforme os objetos artísticos oferecem um lugar para pensar na conciliação entre diferentes: entre a cruz e o tridente, entre Cristo e Exu e entre cristãos e religiões de matriz africana

An investigation into the rheological properties of different lead-free solder pastes for surface mount applications

Purpose – The purpose of this paper is to investigate the rheological behaviour of three different lead-free solder pastes used for surface mount applications in the electronic industry.Design/methodology/approach – This study concerns the rheological measurements of solder paste samples and is made up of three parts. The first part deals with the measurement of rhelogical properties with three different measuring geometries, the second part looks into the effect of frequencies on oscillatory stress sweep measurements and the final part reports on the characterisation and comparison of three different types of Pb-free solder pastes. Findings – Among the three geometries, the serrated parallel plate was found effective in minimising the wall-slip effect. From the oscillatory stresssweep data with different frequencies; it was observed that the linear visco-elastic region is independent of frequency for all the solder paste samples. To understand the shear thinning behaviour of solder paste, the well known Cross and Carreau models were fitted to the viscosity data. Moreover,creep-recovery and dynamic frequency-sweep tests were also carried out without destroying the sample’s structure and have yielded useful information on the pastes behaviour.Research limitations/implications – More extensive research is needed to fully characterise the wall-slip behaviour during the rheological measurements of solder pastes. Practical implications – The rheological test results presented in this paper will be of important value for research and development, quality control and facilitation of the manufacturing of solder pastes and flux mediums. Originality/value – This paper shows how wall-slip effects can be effectively avoided during rheological measurements of solder pastes. The paper also outlines how different rheological test methods can be used to characterise solder paste behaviours

The dominions of the Czar of Russia Alba or Great Duke of Moscovia in which are the Dukedoms of Moscow, Wolodimer, Rezan, Worotin, Novogorod-Sewierski, Czernihow, Smolensko, Reschow, Twer, Novogorod-Weliki, Biele Jezora, Wologda, .. /

1 kartta :, käsinvär. ;, 57 x 88 cm, lehti 62,5 x 92,5 cm

Dynamic distributed lanes: motion planning for multiple autonomous vehicles

Unorganized traffic is a generalized form of travel wherein vehicles do not adhere to any predefined lanes and can travel in-between lanes. Such travel is visible in a number of countries e.g. India, wherein it enables a higher traffic bandwidth, more overtaking and more efficient travel. These advantages are visible when the vehicles vary considerably in size and speed, in the absence of which the predefined lanes are near-optimal. Motion planning for multiple autonomous vehicles in unorganized traffic deals with deciding on the manner in which every vehicle travels, ensuring no collision either with each other or with static obstacles. In this paper the notion of predefined lanes is generalized to model unorganized travel for the purpose of planning vehicles travel. A uniform cost search is used for finding the optimal motion strategy of a vehicle, amidst the known travel plans of the other vehicles. The aim is to maximize the separation between the vehicles and static obstacles. The search is responsible for defining an optimal lane distribution among vehicles in the planning scenario. Clothoid curves are used for maintaining a lane or changing lanes. Experiments are performed by simulation over a set of challenging scenarios with a complex grid of obstacles. Additionally behaviours of overtaking, waiting for a vehicle to cross and following another vehicle are exhibited.

Al-Mahdi - Gestalt och budskap : En litteraturstudie jämförande sudanesisk Mahdi och indisk Mahdi inom islam

Followers of three world religions, Judaism, Christianity and Islam are waiting for the Messiah. Muslims are even waiting for aspiritual leader al-Mahdi. Two different persons claimed the title of al-Mahdi, at the end of the nineteenth century. Theyappeared almost at the same time, at the totally different places of the earth, with a completely different message and underthe rule of the British colonial power. The aim of the study is to compare the both religious figures, Mirza Ghulam Ahmadfrom India and Muhammad Ahmad from Sudan regarding their different messages, to illustrate the social, political andreligious factors that lead to the entirely different profile and image of these two men and how their organizations havedeveloped after their death up till today. The result shows that the Sudanese Mahdi Muhammad Ahmad claimed hisMahdiship in the year 1881. He became a political leader in a time when Sudan was under the rule of a colonial power. Hetook advantage of the religion for personal purposes and tried to liberate his native country Sudan. The contemporaryMuslim clergy criticized him for his claim because the content of the Hadith traditions did not support his claim ofMahdiship. He maintained his sole right for the interpretation of religion and of the laws of Sharia. He made changes even inthe chief pillars of Islam by asserting that Jehad with sword was more imperative than the pilgrimage journey to Mecca. Heasserted that the Prophet Muhammad himself had entrusted him to launch the holy war against the non-believers. He hadimmense ambitions which were never fulfilled since he suddenly died four years after his claim for Mahdiship, in June 1885.This day his followers are organized as a political party in Sudan with a modest roll in the Sudanese politics. The IndianMahdi Mirza Ghulam Ahmad claimed in 1889 to be Mahdi, Mujaddid, Muhaddas, Messiah and a Prophet at a time of socialand political peace, though Islam as a religion was firmly pushed by the Hindu and Christian missionaries. He had no politicalambitions at all and was utterly loyal to the British colonial power. His mission was to crush the Cross and to demonstrateIslam’s excellence over all the religions of the world through overwhelming arguments. He proclaimed that Jesus was humanand a Prophet and not the son of God. Jesus survived from the cross and died a natural death after he had lived for manyyears. Ahmad claimed that God had commanded him to put stop to the religious wars. The contemporary Muslim clergyblamed him for being an imposter, melancholic and hypochondriac who had self invented the divine revelations. He died year1908, nineteen years after his claim and the communion he found is established today in more than hundred countries of theworld. Reasons for the breakdown of mission of the Sudanese Mahdi were that his objectives were political and he challengedthe colonial power with the sword. Another decisive factor was his sudden death merely four years after the beginning of hismission. Reasons for the success of Indian Mahdi were that his objectives were purely religious and he was wholly loyal to theforeign government. He survived nineteen years after the beginning of his mission which made it possible for him to create acommunion based on solid grounds. His followers continued on the same path and never engaged in local politics where everthey lived. For further studies it will be of great interest to study the life of Mirza Ghulam Ahmad and objectively examine thearguments he presented in support of his divine appointment. Furthermore it is enriching to study the organization andactivities of the Ahmadiyya Muslim community to explore if they are in accordance with the basic principles of Ahmad.

Laminados compósitos de PRFV: efeitos da descontinuidade geométrica e do envelhecimento ambiental acelerado

The growing demand in the use of composite materials necessitates a better understanding of its behavior related to many conditions of loading and service, as well as under several ways of connections involved in mechanisms of structural projects. Within these project conditions are highlighted the presence of geometrical discontinuities in the area of cross and longitudinal sections of structural elements and environmental conditions of work like UV radiation, moisture, heat, leading to a decrease in final mechanical response of the material. In this sense, this thesis aims to develop studies detailed (experimental and semi-empirical models) the effects caused by the presence of geometric discontinuity, more specifically, a central hole in the longitudinal section (with reduced cross section) and the influence of accelerated environmental aging on the mechanical properties and fracture mechanism of FGRP composite laminates under the action of uniaxial tensile loads. Studies on morphological behavior and structural degradation of composite laminates are performed by macroscopic and microscopic analysis of affected surfaces, in addition to evaluation by the Measurement technique for mass variation (TMVM). The accelerated environmental aging conditions are simulated by aging chamber. To study the simultaneous influence of aging/geometric discontinuity in the mechanical properties of composite laminates, a semiempirical model is proposed and called IE/FCPM Model. For the stress concentration due to the central hole, an analisys by failures criteria were performed by Average-Stress Criterion (ASC) and Point-Stress Criterion (PSC). Two polymeric composite laminates, manufactured industrially were studied: the first is only reinforced by short mats of fiberglass-E (LM) and the second where the reinforced by glass fiber/E comes in the form of bidirectional fabric (LT). In the conception configurations of laminates the anisotropy is crucial to the final mechanical response of the same. Finally, a comparative study of all parameters was performed for a better understanding of the results. How conclusive study, the characteristics of the final fracture of the laminate under all conditions that they were subjected, were analyzed. These analyzes were made at the macroscopic level (scanner) microscope (optical and scanning electron). At the end of the analyzes, it was observed that the degradation process occurs similarly for each composite researched, however, the LM composite compared to composite LT (configurations LT 0/90º and LT ±45º) proved to be more susceptible to loss of mechanical properties in both regarding with the central hole as well to accelerated environmental aging

Caracterização morfológica e sedimentologica da plataforma, continental brasileira adjacente aos municípios de Fortim, Aracati e Icapuí- CE

The study area is located on the Brazilian Continental Shelf adjacent to Ceará State, inserted in the submerged Potiguar Basin. This area was submitted to extensional efforts during Upper Cretaceous, associated to the begining of the rifting that resulted in African and South American Continent separation. The main goal of this research was to better understand the sedimentary and geomorphological characteristics of the continental shelf adjacent to Fortim, Aracati and Icapuí (Ceará State). The used data base included geophysical (sides scan sonar and bathymetry studies) and sedimentological survey, associated to satellite image processing and interpretation. Inferences about suspended material and longshore drift was possible using satellite images, and differente bedforms were characterized such as: different kinds of dunes (longitudinal, cross and oblique), bioclastic banks, paleochannels, flat and rock bottom. The researched area comprehended about 2509,13 km2, where 6 different sedimentary facies, based on sediment composition and texture, could be recognized, such as: Bioclastic Sand, Siliciclastic Sand, Biosiliciclastic Sand, Bioclastic gravel, Biosiliciclastic sand with granule and gravel, and Silicibioclastic sand with granule and gravel. The integration of bathymetric, satellite image, side scan sonar and sedimentological data allow us a better characterization of this continental shelf area, as to advance in the knowledge of the continental shelf of the state of Ceara, a very important area to the oil industry because of its potential exploration and e exploitation, and to environmental survey as well

Crescimento dos tecidos muscular e adiposo de fêmeas bovinas de diferentes grupos genéticos no modelo biológico superprecoce

Objetivou-se avaliar o crescimento de novilhas de diferentes grupos genéticos no sistema de produção superprecoce. Utilizaram-se 132 novilhas dos seguintes grupos genéticos: 18 ¾ Canchim × ¼ Nelore (¾ CN); 18 ½ Canchim × ½ Nelore (½ CN); 24 Simbrasil -⅝ Simental × ⅜ Nelore; e 72 Three-cross ¼ Simental × ¼ Nelore × ½ Angus. As novilhas foram desmamadas aos 210 dias de idade, com 247,4 ± 16,5 kg de peso vivo (PV), mantidas em creep-feeding durante a fase de cria e confinadas por 132 ± 14 dias até atingirem 350 kg PV e 5 mm de gordura subcutânea, quando, então, foram abatidas. Os grupos genéticos não influenciaram o ganho de peso médio diário, porém a espessura de gordura subcutânea do dorso (EGS) e da garupa (EGG) foi maior nos animais Three-cross, que apresentaram os maiores valores iniciais (1,07 kg/dia). Não houve diferença na área de olho-de-lombo (AOL) inicial, porém a os animais Three-cross apresentaram os maiores valores iniciais. Nos animais do grupo Three-cross, a área de olho-de-lombo (AOL) final e ajustada para 100 kg de peso vivo (PV) foi inferior à observada nos demais grupos, porém o peso final foi superior ao do grupo Simbrasil, com tempo intermediário de confinamento. Ajustando-se os valores de AOL e EGG para o menor número de dias de confinamento (114 dias), animais Simbrasil apresentam maior valor de AOL final e os animais Three-cross e Simbrasil, maior EGG final.

Quantitative trait loci associated with chemical composition of the chicken carcass

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)