Summary of structure design possibility. Proposal of structure design. Hardware proposal. Software proposal. Gearing calculation.

The aim of this diploma thesis is to design and implement a universal driver unit designed to control electric motors of small voltages – electronically commutated, DC and stepper. This involves creating topology and selecting appropriate components based on the required parameters. It also includes the manufacture of printed circuit board (PCB), soldering of the components and programming of the necessary functions. Thesis contains the analysis of three selected types of motors – the principle of operation, wiring and control. Testing of the control unit was performed at the end of the work.

The development of phased array antenna systems requires considerable resources and time. Due to this constraint, the Naval Air Command (NAVAIR) needs a phased array that can be physically reconfigured to meet the demands of multiple missions without added development time or cost. This work develops and demonstrates a solution to this problem by implementing an adaptive calibration approach to the development of electronically steerable antennas (ESAs). In contrast to previous analog adaptive beamformer systems, this system allows for an arbitrary antenna configuration with a variable number of antenna elements and locations. A simulation model of arbitrary phased array configurations was developed to test the beamformer calibration algorithm and was used to show practical tile locations. To demonstrate this approach, four 4x4 ULA phased array antenna tiles were built and tested together in various configurations to show the viability of developing a physically reconfigurable phased array system.

No description available.

De nos jours, les antennes à réseaux transmetteurs attirent un grand intérêt pour de nombreuses applications civiles et militaires aux bandes de fréquence comprises entre 10 et 110 GHz (réseaux de communication 5G, liens point à point, radars, etc.).Le travail de thèse vise à faire des innovations dans la modélisation et la conception d'antennes à réseaux transmetteurs pour des applications en bande Ka (28-40 GHz). Il porte plus précisément sur le développement d'outils numériques pour l’analyse théorique des réseaux transmetteurs, la conception et la démonstration de plusieurs prototypes avec des fonctionnalités avancées, telles que des réseaux transmetteurs passifs (larges bandes ou à multifaisceaux) et actifs (à reconfiguration électronique).La première partie des travaux consiste en une analyse théorique des réseaux transmetteurs. Dans un premier temps, l’impact de la méthode de compensation de phase sur les performances des réseaux transmetteurs est étudié. La loi de compensation de phase de l’onde quasi-sphérique incidente sur l’ouverture du réseau transmetteur est calculée en utilisant deux méthodes nommées compensation à phase constante et compensation par ligne à retard, et nous montrons que cette dernière permet d’augmenter la bande passante du réseau transmetteur et de corriger les erreurs de dépointage du faisceau. Dans un second temps, le principe de fonctionnement des réseaux transmetteurs facettés est décrit en détail. La simulation numérique du réseau transmetteur à trois facettes est validée au travers de simulations électromagnétiques 3-D. Pour un certain angle d’inclinaison, nous montrons que la bande passante et la capacité de dépointage du réseau transmetteur sont améliorées au détriment du gain.La suite des travaux porte sur la conception et le prototypage de deux réseaux transmetteurs passifs, dont l’un à faisceau collimaté et très large bande et l’autre à quatre faisceaux fixes. Les deux réseaux transmetteurs sont basés sur une cellule élémentaire à 3bits qui assure une double fonction à savoir la compensation de phase et la conversion de la polarisation linéaire en circulaire. Le réseau passif à faisceau collimaté présente un gain mesuré de 33,8 dBi (correspondant à une efficacité d'ouverture de 51,2%) et une bande passante à -3 dB supérieure à 15,9%. La distribution de phase du réseau transmetteur à quatre faisceaux a été optimisée par un algorithme génétique afin d’avoir des faisceaux dépointés à ± 25° dans le plan horizontal et le plan vertical à la fréquence d’optimisation.La dernière partie des travaux vise la conception d’un réseau transmetteur reconfigurable à 27-31 GHz. Dans un premier temps, une cellule élémentaire active à quatre états de phase (2 bits) en polarisation linéaire a été conçue et validée expérimentalement. Elle est composée de six couches métalliques imprimées sur trois substrats. Les éléments rayonnants sont des antennes patch rectangulaires comprenant chacun deux diodes PIN pour contrôler la phase de transmission. Le principe de fonctionnement de la cellule élémentaire a été validé expérimentalement avec des pertes d’insertion minimales de 1.6-2,1 dB et une bande passante en transmission (à 3 dB) de 10-12,1% pour les quatre états de phase 0 °, 90°, 180° et 270°. Cette cellule a ensuite été utilisée pour la conception d’un réseau transmetteur reconfigurable comprenant 14 × 14 cellules unitaires et 784 diodes PIN. Un prototype a été réalisé et caractérisé, il présente un gain maximum mesuré de 19,8 dBi, correspondant à une efficacité d'ouverture de 23,5%, et une bande passante à 3 dB de 4,7 GHz (26,2-30,9 GHz). Malgré quelques éléments défaillants, ce prototype valide le principe de fonctionnement et la faisabilité de réseaux transmetteurs en bande Ka avec une quantification de phase de 2 bits et constitue une des premières réalisations de ce type dans l’état de l’art actuel. / Nowadays, transmitarray antennas are of great interest for many civil and military applications in frequency bands between 10 and 110 GHz (5G mobile networks, point-to-point communication systems, radars, etc.).This thesis aims to make major innovations in modeling and design of transmitarray antennas for Ka-band applications (28-40 GHz). It focuses on the development of numerical tools, and the design and demonstration of several prototypes with advanced functionalities, such as passive (broadband or multibeam) and active (at electronic reconfiguration) transmitarrays.The first part of the work consists of a theoretical analysis of the transmitarray antenna. In a first step, the impact of the phase compensation method on the performance of the transmitarray is studied. The phase compensation law of the quasi-spherical wave incident on the array aperture is calculated using two methods called constant phase compensation and true-time delay (TTD) compensation. The numerical results show that TTD compensation allows an increase of the transmitarrays bandwidth and a reduction of the beam squint as compared to constant phase-shift compensation. In a second step, the operating principle of facetted transmitarrays is described in detail. The numerical simulation of a 3-facet transmitarray is validated through 3-D electromagnetic simulations. For a certain facet angle, the bandwidth and the beam scanning capability of the TA are improved at the expense of the gain.The next step of the work concerns the design and prototyping of two passive transmitarray antennas, one with a collimated and a large bandwidth, and the other with four fixed beams. The two transmitarrays are based on a 3-bit unit-cell providing two functions, namely the phase compensation and the polarization conversion from linear to circular. The passive beam-collimated transmitarray exhibits a measured gain of 33.8 dBi (corresponding to an aperture efficiency of 51.2%) and a 3-dB gain-bandwidth larger than 15.9%. The quad-beam transmitarray phase distribution has been optimized by a genetic algorithm code coupled with an analytical tool. The array is designed to radiate four beams at ±25° in the horizontal and vertical planes at the optimization frequency.The last part of the work aims to the design of a 27-31 GHz reconfigurable transmitarray antenna. Initially, an active unit-cell with four phase states (2 bits) in linear polarization was designed and validated experimentally. It consists of six metal layers printed on three substrates. The radiating elements are rectangular patch antennas, each of them including two PIN diodes to control the transmission phase. The operating principle of the unit-cell has been experimentally validated with a minimum insertion loss of 1.6-2.1 dB and a 3-dB transmission bandwidth of 10-12.1% for the four phase states. 0°, 90°, 180° and 270°.Then, this unit-cell was used for the design of a reconfigurable transmitarray antenna comprising 14 × 14 unit cells and 784 PIN diodes. A prototype was realized and characterized, it presents a measured maximum gain of 19.8 dBi, corresponding to an aperture efficiency of 23.5%, and a 3-dB bandwidth of 4.7 GHz (26.2% at 30.9 GHz). Despite some faulty elements, this prototype validates the operating principle and the feasibility of Ka-band transmitarray antennas with a 2-bit phase quantization. It is one of the first demonstration of such an antenna in the current state of the art.

Made available in DSpace on 2016-04-27T18:12:39Z (GMT). No. of bitstreams: 1 Millena Nobrega Campos de Sousa.pdf: 1030142 bytes, checksum: fc11f9c7d90aa6efa2c5cd789b259a0e (MD5) Previous issue date: 2009-02-19 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Introduction: The electronically amplified music represents an occupational exposure to noise for employees of nightclubs. Such exposure can cause health effects of these workers. Aim: Verifying the effects of noise on hearing and health of employees of nightclubs in the city of Sao Paulo, exposed to electronically amplified music. Method: The sample comprised 50 employees of two nightclubs in the city of Sao Paulo. The procedures were performed: anamnesis, tympanometry and Distortion-Product Otoacoustic Emissions (DPOAE). Results: The most complaints were: tinnitus (18.0%) and intolerance to loud sounds (16.0%), headache (24.0%) and insomnia (22.0%), respectively. Most employees 31(81.6%) reported audiometry within the normal pattern of bilateral normality. The DPOAE test showed absence of responses in the left ear in 21 (42.0%) employees and 17 (34.0%) in the right ear. The absence was bilateral in 22% of the sample (n = 11). The most affected were f2 3174 Hz, 4004 Hz and 6348 Hz. There was a correlation between the results of DPOAE of the right ear with only the variables complained of dizziness and smoking habits. Conclusion: The DPOAE test may be useful for early identification of changes that come in a PAIR employees exposed to electronically amplified music / Introdução: A música eletronicamente amplificada representa a exposição ocupacional a ruído para funcionários de casas noturnas. Tal exposição pode ocasionar efeitos na saúde destes trabalhadores. Objetivos: Verificar a ocorrência dos efeitos do ruído sobre a audição e a saúde em funcionários de casas noturnas da cidade de São Paulo, expostos à música eletronicamente amplificada. Método: A amostra foi composta por 50 funcionários de duas casas noturnas da cidade de São Paulo. Os procedimentos realizados foram: questionário, timpanometria e teste de emissões otoacústicas - produto de distorção (EOAPD). Resultados: As queixas mais encontradas foram: zumbido (18,0%) e intolerância a sons fortes (16,0%), dor de cabeça (24,0%) e insônia (22,0%), respectivamente. A maioria dos funcionários 31 (81,6%) relatou audiometria dentro dos padrões de normalidade. O teste de EOAPD apresentou ausência de respostas na orelha esquerda em 21 (42,0%) funcionários e em 17 (34,0%) na orelha direita. A ausência bilateral ocorreu em 22% da amostra (n=11). As f2 mais acometidas foram 3174 Hz, 4004 Hz e 6348 Hz. Houve correlação entre os resultados da EOAPD da orelha direita apenas com as variáveis queixa de tontura e hábito de fumar. Conclusão: O teste de EOAPD pode ser útil na identificação precoce das alterações que procedem a PAIR em funcionários expostos à música eletronicamente

EU beslutade 2002 om en särskild beskattningsanordning i syfte att undanröja konkurrenssnedvridningar vid försäljning av elektroniska tjänster. Frågetecken om var eller av vem som moms ska erläggas kan ibland uppstå. Förvaltningsrätten och regeringen har gjort olika bedömningar beträffande mervärdesskatteskyldighet för två svenska företag vars tjänster varit underkastade moms i andra länder. Medan förvaltningsrätten dömde företag A att betala mervärdeskatt befriade regeringen företag B från mervärdebeskattning. Syftet är att utreda hur skattskyldighet beträffande samma elektroniska tjänster kan uppkomma i olika medlemsländer samt om de som tillhandahåller dessa tjänster säljer till eller ifrån fasta etableringsställen eller om de är att betrakta som återförsäljare. Varför samma skattskyldighet uppkommer i olika medlemsländer kan delvis härledas till de avvikelser som finns mellan svensk rätt och EU-rätt beträffande innebörden av de olika begrepp som används för att beteckna momsredovisningsskyldiga. Det kan även bero på den vaga och vida definition som begreppet elektroniska tjänster innefattar samt de skillnader som finns mellan språkversionerna beträffande vad som ska anses omfattas. Tillhandahållare av elektroniska tjänster ska erlägga mervärdeskatt i det land där köparen har sätet för sin ekonomiska verksamhet eller där det fasta etableringsstället finns till vilka tjänsterna tillhandahålls. Vid omsättning eller förvärv av tjänster är det den som agerar som faktisk säljare eller den kund som faktiskt förvärvar och konsumerar tjänsten som avgör var omsättningen anses belägen. Bedömningen ska fokusera på de huvudsakliga momenten för tjänsten ifråga. Tillhandahållare av elektroniska tjänster är inte att betrakta som återförsäljare eftersom de inte uppfyller de kriterier som finns uppställda för begreppet återförsäljare. Därmed kan en analogi inte göras gällande. / In 2002 the member states of EU took a decision regarding whether to introduce a special tax base on digital supplies or not. This tax base was later on implemented to the member states domestic laws. Question may sometimes arise as to where or by whom VAT should be paid regarding electronically supplies. The administrative court and the Swedish government have made different judgments regarding two Swedish companies whose services already have been subject to VAT in other member states. While the administrative court sentenced company A to pay VAT the government exempted company B. This bachelor thesis will examine how tax claims regarding the same electronically supply can occur in different member states and if the providers are selling to or from a permanent establishment or if they are to be considered as distributors. The answer to the first question can partly be due to the difference between Swedish law and EU-law regarding the different use of word for designating a taxable person. The words used for designating a taxable person have different meanings which can constitute confusion. It can furthermore be due to the vague and broad definition for the term electronically supplies and the differences that occur, regarding what can be covered by the definition of electronically supplies. Providers of digital supplies shall pay VAT in the country where the buyer has his place of business or where the fixed establishment is located to which the supplies are provided. Regarding revenue or acquisition it is the one who acts like the real seller or the customer who acquires and consumes the provided service who determines where the supply is situated. The main elements for the services provided have to be examined. Providers of digital supplies are not to be regarded as distributors because they do not meet the criteria’s that are set out for the term.

A cryogenic (325-80 K) ion mobility-mass spectrometer was designed and constructed in order to improve the analytical figures-of-merit for the chemical analysis of small mass analytes using ion mobility-mass spectrometry. The instrument incorporates an electron ionization source, a quadrupole mass spectrometer, a uniform field drift cell spectrometer encased in a cryogenic envelope, and an orthogonal geometry time-of-flight mass spectrometer. The analytical benefits of low temperature ion mobility are discussed in terms of enhanced separation ability, ion selectivity and sensitivity. The distinction between resolving power and resolution for ion mobility is also discussed. Detailed experimental designs and rationales are provided for each instrument component. Tuning and calibration data and methods are also provided for the technique. Proof-of-concept experiments for an array of analytes including rare gases (argon, krypton, xenon), hydrocarbons (acetone, ethylene glycol, methanol), and halides (carbon tetrachloride) are provided in order to demonstrate the advantages and limitations of the instrument for obtaining analytically useful information. Trendline partitioning of small analyte ions based on chemical composition is demonstrated as a novel chemical analysis method. The utility of mobility-mass analysis for mass selected ions is also demonstrated, particularly for probing the ion chemistry which occurs in the drift tube for small mass ions. As a final demonstration of the separation abilities of the instrument, the electronic states of chromium and titanium (ground and excited) are separated with low temperature. The transition metal electronic state separations demonstrated here are at the highest resolution ever obtained for ion mobility methods. The electronic conformational mass isomers of methanol (conventional and distonic) are also partially separated at low temperature. Various drift gases (helium, neon, and argon) are explored for the methanol system in order to probe stronger ion-neutral interaction potentials and effectuate higher resolution separations of the two isomeric ions. Finally, two versatile ion source designs and a method for axially focusing ions at low pressure (1-10 torr) using electrostatic fields is presented along with some preliminary work on the ion sources.

The purpose of this paper is to present all participants of the Dresden Conference the digital School Journal Revista Escolar de la Olimpiada Iberoamericana de Matemática, online since May-June 2002, with lmost 16,000 subscribers at current issue number 32. Subscribers are based all over the world, but mostly in Spain, Portugal and Latin America.

No description available.