O aço 10B06 é utilizado na produção de fio máquina para trefilação. Por ser produzido em aciaria elétrica, o teor de nitrogênio desse aço tende a ser elevado, o que pode causar o fenômeno de envelhecimento, resultando em aumento de resistência e queda de ductilidade. Reduzir o teor de nitrogênio livre é uma forma de minimizar esse efeito, o que é realizado pela adição de boro. Dessa forma, o presente trabalho teve como objetivo estudar o efeito do boro no aço 10B06. Foram utilizadas amostras de fio máquina, diâmetro 5,50mm, e arame trefilado com teores de boro variando de 55 a 112ppm. Os dois principais fatores que influenciam a microestrutura e propriedades mecânicas do material são a composição química e o processo produtivo. Por esse motivo, inicialmente foi avaliada a etapa de resfriamento durante a laminação do fio máquina, por meio de uma análise termográfica. Foi encontrada a temperatura de 767ºC no início do resfriamento do material, valor próximo de Ac1, limite inferior do intervalo intercrítico. Esse fato favorece o enriquecimento da austenita em carbono, facilitando a formação de martensita e/ou austenita retida. Os resultados da análise metalográfica com Nital revelaram microestrutura composta de aproximadamente 88% de ferrita e 12% de perlita. Já o reagente Le Pera identificou ilhas de martensita e/ou austenita retida (MA), o que foi comprovado por análises de microscopia eletrônica de varredura. Os resultados de microdureza mostraram uma tendência de queda com o aumento do teor de boro. As medições de nanodureza confirmaram a presença do microconstituinte MA. A ferrita apresentou dureza na faixa de 280 - 320 HV, enquanto o MA ficou no intervalo de 349 - 424 HV. Comparando-se o limite de resistência obtido no fio máquina com menor teor de boro (55ppm - 434MPa) com o de maior (112ppm - 394MPa), observasse uma redução de 40MPa para um acréscimo de 57ppm de boro, confirmando o efeito esperado para esse elemento pela formação de BN. Utilizando os dados da curva tensão versus deformação foram obtidos os coeficientes de encruamento dos fios máquina, que apresentaram uma tendência de crescimento com o teor de boro, sendo que o material com 101ppm de boro mostrou o melhor valor para aplicação em processos de conformação. As análises fractográficas revelaram que os mecanismos de fratura presentes em todos os materiais foram a formação e coalescimento de microvidades. Considerando-se todas as análises realizadas nesse trabalho foi possível evidenciar o efeito do boro na redução do efeito do envelhecimento provocado pelo nitrogênio. Entre os testes realizados, os que apresentaram as melhores relações B/N foram os de teores 109 e 112ppm de boro. Essas relações estão próximas do valor máximo indicado de 0,8. / The 10B06 steel grade is applied to the production of wire rod for drawing. The steel is produced in an Electric Arc Furnace and this process can lead to higher nitrogen levels that cause strain aging resulting in an increase of the strength and ductility loss. The reduction of free nitrogen content through boron addition is one way to minimize this effect that can be done through boron addition. In this way, the present work aims to study boron effect on 10B06 steel. It was used wire rod, diameter 5,50mm and a cold-drawn wire rod with chemical composition from 55 to 112ppm of boron. The main factors that influence the microstructure and mechanical properties of the material are the chemical composition and the productive process. For this reason, initially, the cooling treatment was analyzed using thermography and it was found at the beginning of the cooling process a temperature of 767oC in the material, close to Ac1, lower limit of the intercritical interval. This temperature can facilitate the enrichment of carbon in the austenite, making easier martensite and/or retained austenite formation. The metallographic analysis with Nital etchant showed a microstructure composed of about 88% ferrite and 12% perlite, and Le Pera etchant identified martensite and/or retained austenite (MA), what was confirmed by scanning electron microscope analysis. Furthermore, nanohardness measurements confirmed the presence of the microconstituent MA, as ferrite presented hardness from 280 to 320 HV and MA from 349 to 424 HV. Microhardess results decreased with increasing boron content. A decrease of 40MPa in the tensile strength was observed between the wire rod with boron content of 55ppm (434MPa) and the one with 112ppm (394MPa), in agreement with the expected effect of the BN formation. It was possible to obtain hardening coefficient of the wire rod using the data of the stress versus strain curve, which increased with boron content, and the material with 101ppm of boron showed the best value for forming application. Fractographic analysis revealed that the fracture mechanisms in all the materials were the development and coalescing of microcavity. Considering all the analysis of this study it was possible to confirm boron\'s effect to reduce strain aging caused by nitrogen. Materials with 109 and 112ppm of boron presented the best B/N ratio, with values close to the maximum indicated, 0,8.

A principal característica de cabos é a sua capacidadede suportar grande carga na direção longitudinal e são utilizadas em, por exemplo, concreto comprimido, plataformas e pontes. Usualmente, sua estrutura básica é formada por um elemento central (núcleo) e reto juntamente com outros componentes dispostos ao seu redor em forma de hélice. Existe uma variedade de geometrias que podem ser utilizadas, assim como número de camadas. Seguindo a teoria de vigas espaciais e parametrizando a geometria, a linha média de apenas uma dessas hélices foi analisada analiticamente. Essa simplificação é valida visto que o contato e deslizamento não são incluídos nesta teoria, produzindo uma primeira abordagem ao problema da modelagem dessas estruturas. Sendo assim, as equações de equilíbrio foram deduzidas e seu sistema diferencial foi resolvido com o objetivo de representar o comportamento mecânico da estrutura. Utilizando a tríade de Frenet-Serret para definir um sistema de coordenadas local, as condições de contorno foram aplicadas buscando determinar as constantes de integração resultantes da solução analítica das equações diferenciais. Essa solução foi comparadas com resultados numéricos obtidos pelo Método dos Elementos Finitos (FEM) para validação dos casos de carga concentrada e distribuída em duas geometrias, o arco plano e a hélice. Em ambos os casos resultados apresentaram boa concordância para forças, momentos, rotações e deslocamentos. Considerando o caso do arco, o seu raio foi aumentado, de forma que a geometria se aproximasse de uma viga reta. O modelo proposto também foi utilizado para simular uma mola sob compressão. / A high number of structures uses cables due to their ability to bear large load in the longitudinal direction, for example, prestressed concrete, offshore systems and bridges. Its basic structure is formed by a central straight element surrounded by strands laid helically. A variety of geometries can be used, as well as the number of layers. Using the theory of spatial beams and parameterizing the geometry, the center line of only one of these helixes was analyzed analytically, since contact and slip are not included in this theory, obtaining a first approach in order to model these structures and to determine its mechanical behavior. Thus, the equilibrium equations were deduced and the differential system was solved with the objective of representing the mechanical behavior of the structure. Using the Frenet-Serret triad to define a local coordinate system, the boundary conditions were applied aiming the determination of the integration constants. The expressions obtained were compared with results obtained by the Finite Element Method (FEM) for validation applying concentrated and distributed loads. All cases presented good agreement FOR forces, moments, rotations and displacements. Considering the arc case, its radius was increased until a straight beam. The proposed model was also used to simulate a spring under compression.

This work enables accelerated fluid recovery in oil and gas reservoirs by automatically controlling fluid height and bottomhole pressure in wells. Several literature studies show significant increase in recovered oil by determining a target bottomhole pressure but rarely consider how to control to that value. This work enables those benefits by maintaining bottomhole pressure or fluid height. Moving Horizon Estimation (MHE) determines uncertain well parameters using only common surface measurements. A Model Predictive Controller (MPC) adjusts the stroking speed of a sucker rod pump to maintain fluid height. Pump boundary conditions are simulated with Mathematical Programs with Complementarity Constraints (MPCCs) and a nonlinear programming solver finds a solution in near real-time. A combined rod string, well, and reservoir model simulate dynamic well conditions, and are formulated for simultaneous optimization by large-scale solvers. MPC increases cumulative oil production vs. conventional pump off control by maintaining an optimal fluid level height.

This report investigates the sensitivity of the control rod depletion coefficients, Sg, to different input parameters and how this affects the accumulated 10B depletion, β. Currently the coefficients are generated with PHOENIX4, but the geometries can be more accurately simulated in McScram. McScram is used to calculate Control Rod Worth, which in turn is used to calculate Nuclear End Of Life, and Sg cannot be generated in the current version of McScram. Therefore, it is also analyzed whether the coefficients can be related to CRW and thus be studied indirectly through it. Simulations of the coefficients were done in PHOENIX4, simulations of CRW were done in both PHOENIX4 and McScram and simulations of β were done in POLCA7. All simulations were performed for a CR99 in a BWR reactor. The control rod coefficients were found to be sensitive to the enrichment of the fuel, void fraction of the water and the width of the gap, and these effects were also seen in the results of β. As a result, one of three steps could be taken. First, the parameter values should not be set arbitrarily, instead default values could be chosen such that Sg is calculated more accurately. Second, a set of tables of Sg could be generated for different parameter values so that β can be calculated with Sg from the current conditions, although this would mean that PHOENIX4 needs to be updated. Third, McScram can be updated to be able to calculate Sg directly. It has been concluded that Sg cannot be studied indirectly through CRW since the trends and the sensitivity to the different parameters were not consistent between Sg, CRW calculated with PHOENIX4 and CRW calculated with McScram, where PHOENIX4 was more sensitive than McScram. The results can instead be used to bench-mark the PHOENIX4 results.

<p>Cilj istraživanja je da se dokumentuju različiti identiteti profesorki univerziteta koje su oti&scaron;le iz Srbije u razne akademske sredine u svetu i ostvarile profesionalnu karijeru.<br />Hipoteze su shodno cilju rada:<br />H-1: Prva hipoteza je da su profesorke u akademskoj dijaspori oti&scaron;le u inostranstvo kako bi uspe&scaron;no izgradile profesionalnu karijeru u vreme kada u zemlji porekla za to nisu postojali dovoljni uslovi u onim naučnim disciplinama za koje su se one opredelile.<br />H-2: Druga hipoteza je da sve profesorke u akademskoj dijaspori imaju promenljive, vi&scaron;estruke identitete.<br />H-3: Treća hipoteza je da empirijski podaci o životu profesorki u akademskoj dijaspori pomažu da se izgradi strategija saradnje profesorki iz dijaspore sa univerzitetskim centrima ovde.<br />Osnovni i kontrolni korpus za analizu čini 21 životna priča profesorki koje su obrazovanje za karijeru stekle na univerzitetima u Srbiji, a profesionalnu karijeru ostvarile u raznim zemljama Evrope i sveta. Audio zapisi snimljenog razgovora za ukupno 11 profesorki, zabeleženi tokom &scaron;est godina (2009-2015), audio zapisom (24 sata) na osnovu polustrukturiranog upitnika, transrkibovani u formu pisanog teksta (256 stranica). Kao kontrolni korpus empirijskih podatka su objavljenih 10 životnih priča profesorki sa Univerzitetu u Novom Sadu (Savić 2015). Osnovni kriterijumi za odbir žena su: da su rođene u Republici Srbiji (gde su provele detinjstvo, deo ili svo obrazovanje), a ostvarile akademsku karijeru u nekoj od zemalja sveta.<br />Podaci pokazuju da su sve profesorke uskladile profesionalni i privatni život i da je jedan hranio drugi u njihovoj uspe&scaron;noj karijeri.<br />Za profesionalni rad i za odlazak u zemlje destinacije (prijema) profesorke su imale podr&scaron;ku bračnih partnera, koja je bila neohodna, s obzirom na činjenicu da su sve profesorke u akademskoj dijaspori nailazile na brojne prepreke i izazove od momenta odlaska iz zemlje porekla i tokom građenja karijere (na primer, neke su visoko &scaron;kolovanje ponovile, ili su promenile profesiju ili oblast kojom se bave, a deo je nastavio usavr&scaron;avanje).<br />Obrazovanje je presudno i za vaspitanje potomstva - vrhunsko obrazovanje u skladu sa željama i afinitetima svoje dece.<br />Jezički identitet profesorki u akademskoj dijaspori povezan je sa profesionalnom orijentacijom vi&scaron;e nego sa nacionalnim identitetom.<br />Profesorke su se trudile da njihova deca u dijaspori nauče maternji jezik (jezike) roditelja, iako su deca rođena, ili najveći deo svog života, provode u zemlji destinacije, pa se može govoriti o dva (ili vi&scaron;e) maternjih jezika.<br />Najupečatljivija sličnost profesorki UNS i profesorki u akademskoj dijaspori je njihova jednaka želja i volja za obrazovanjem, usavr&scaron;avanjem i napredovanjem u struci i naučnom radu, bez obzira na cenu i prepreke sa kojima su suočene.<br />Takođe, jednako važna sličnost jeste diskriminacija sa kojom se susreću u građenju svojih karijera, profesorke UNS prilikom napredovanja, a profesorke u akademskoj dijaspori prilikom zaposlenja, bavljenja svojom strukom i, takođe, eventualnog napredovanja.<br />Sve profesorke u akademskoj dijaspori žele profesionalno da sarađuju sa univerzitetima i naučnim (i drugim) institucijama u Srbiji, ali ne postoji sistemsko re&scaron;enje za takvu saradnju u sada&scaron;njem trenutku u Srbiji.<br />Ženska iskustva ovde objedinjena svedoče o neiskori&scaron;ćenim resursima, izostalim u saradnji i angažmanu profesorki iz akademske dijaspore u Srbiji danas. Ona mogu dobro poslužiti za sačinjavanje dugoročne strategije o implementaciji znanja i postignuća akademskih profesorki u domaćem okuženju.<br />Značajno je &scaron;to se u okviru interdisciplinarnih rodnim studija objedinjuje problematika migracija žena, naročito povezano sa profesijama, jer je izvesno da će migracije biti dugoročna tema u budućnosti cele civilizacije. Postoje programi i predmeti koji se bave visokim obrazovanjem žena u profesijama i na kojima se izvode istraživački projekti na kojima se sakuplja empirijski materijal.<br />Mogućnost primene rezultata:<br />1. Empirijski podaci o identitetu akademski obrazovanih žena iz dijaspore, od kojih je jedan i rodni, poslužiće u teorijskoj raspravi o odnosu elemenata identiteta u odnosu na rod.<br />2. Empirijski podaci mogu dobro poslužiti u praksi za predlog strategije za saradnju, eventualni povratak, akademski usmerenih žena iz dijaspore u akademsku elitu u Republici Srbiji (i regionu biv&scaron;e Jugoslavije).<br />3. Bogaćenje postojeće baze podataka životnih priča žena u Republici Srbiji iz različitih nacionalnih zajednica koje su svoje živote ostvarile u 20. i 21. veku.<br />Rezultati doktorske disertacije treba da posluže u razvijanju strategije o implementaciji postignuća akademskih žena u domaćem okuženju.</p> / <p>The goal of the research is to document different identities of female university professors who left Serbia and went to other academic communities throughout the world, in order to achieve their professional career.<br />Hypothesis of the work:<br />H-1: First hypothesis is that female professors of the academic diaspora have left their countries in order to be able to successfully build their professional careers elsewhere, during times when it was impossible for them to do so in their own countries, due to lack of sufficient conditions which would facilitate their domestic careers.<br />H-2: Second hypothesis is that all professors in the academic diaspora have variable, multiple identities.<br />H-3: Third hypothesis: empirical data on lives of professors within the academic diaspora are helpful in building of the cooperation strategy between the professors from diaspora and domestic university centres.<br />The basic and control group of analysis consists of 21 life stories of female professors who have acquired their career education within Serbian universities, while their professional career was established in different countries in Europe and throughout the world. Audio recordings of 11 professors, made during a period of six years (2009-2015) in a form of conversations according to previously prepared semi-structured questionnaires (24h of audio material), were transcribed to a form of written text (256 pages in total). 10 life stories of University of Novi Sad&#39;s female professors were published as a control material (Savic 2015). The basic criteria for the selection of women: they were all born in the Republic of Serbia (where they have spent their childhood and finished some or all of their education), while achieving their career somewhere else in the world, outside Serbia.<br />The data shows that all professors have managed to balance their professional and private life, and it turned out that &quot;one&quot; was facilitating the &quot;other&quot;, during their successful career.<br />All professors had support of their spouses for their professional work as well as for relocation to foreign countries. Such support proved to be necessary, since all of them encountered obstacles and challenges within the academic diaspora, from the moment they left their country as well as during their professional career (e.g.: some of them had to repeat/retake their higher education, or to change the profession or area/field of work, while some of them continued with their academic specialization).<br />Education proved crucial for upbringing of their children, too. Top notch education according to desires and affinities of their children.<br />Language identity of the professors within the academic diaspora is more connected to their professional orientation than to their national identities.<br />Professors have tried to teach their children their mother tongue, even though they were born (or have spent the most of their lives) in foreign countries, so it wouold be safe to say that those children have two (or more) languages that they consider as their native.<br />The most striking resemblance between the professors of the Novi Sad University (UNS) and professors in academic diaspora is their equal desire and thrive for education and advancement within their science and field of work, regardless of the cost and obstacles they have encountered, during that journey.<br />Equaly important similarity is the discrimination they have faced during their careers. UNS professors have faced discrimination on their scientific path and advancement, while academic diaspora professors have faced it regarding their employment, their field of expertise and possible advancement, as well.<br />All professors from academic diaspora are willing to cooperate with universities and other scientific institutions in Serbia, but the lack of systematic solutions for such cooperation in Serbia at this point is preventing them to do so.<br />Female experiences encompassed here, are witnessing the unused resources, which are missing when it comes to cooperation and engagement of academic diaspora professors in Serbia today. They can serve as a starting point for making a longterm strategy on implementation of knowledge and achievements of female academic professors in domestic surroundings.<br />It is significant that the issue of female migration, especially when it is connected to their work and profession, is intertwined within the interdisciplinary gender studies, since it is certain that migrations will be a longterm subject in the future of the whole civilisation. There are programs and courses dealing with higher education of women, collecting empirical material during research projects.<br />Possibilities for application of results:<br />1. Empirical data on identitiy of academically educated women from diaspora (gender being one of them) will serve during theoretical discussions on relationship of the elements of identity and gender.<br />2.Empirical data have practical significance, as they may serve as a proposition and starting point of the cooperation strategy, as well as for the possible return of the female academic experts from the diaspora back to academic elite of Serbia (and the Ex-YU region).<br />3. Enrichment of the existing data base of life stories of women from the Republic of Serbia, members of different national communities, who have accomplished their lives in the 20th and 21st century.<br />The results of the PhD thesis should serve the development of a strategy on implementation of academic women&#39;s achievements, in domestic surroundings.</p>

The use of preformed polymers for the preparation of Langmuir-Blodgett (LB) multilayers is reviewed. Principles for polymer self-organization are outlined and the appropriate molecular designs are discussed. Recent developments in the different classes of polymers for LB multilayers are presented, and their outstanding properties highlighted.

Umströmte Rohr- bzw. Stabbündel sind als Übertrager von Wärmeenergie in einem breiten Spektrum von Anwendungsgebieten zu finden. Beispiele sind Heizkörper, Kühlaggregate, Heizpatronen, industrielle Wärmetauscher und Brennelemente in Kernreaktoren. Für jede dieser Anwendungen besteht die Anforderung, die Wärmeübertragung an den Wärmeübertragerflächen zu optimieren. Dabei besteht eine enge Kopplung zwischen Wärmetransport und Strömungsstruktur. Eine besonders effiziente Form der Wärmeübertragung ist die Verdampfung. Diese wird unter anderem bei Brennelementen in Druckwasserreaktoren genutzt. Hier siedet das Kühlwasser an der Brennstaboberfläche. Durch Kondensation der Dampfblasen in der unterkühlten Kernströmung wird die Wärme dann effizient in die Flüssigphase übertragen. Durch die hohe Verdampfungsenthalpie des Wassers wird beim Strömungssieden ein viel höherer Wärmestrom in das Kühlwasser übertragen, als bei rein einphasig-konvektivem Wärmetransport. Sicherheitstechnisch relevant für Brennelemente in Leichtwasserreaktoren ist der Übergang vom Blasensieden zum Filmsieden (kritischer Wärmestrom). Dieser muss unter allen Umständen vermieden werden, um die Integrität der Brennstabhüllen zu gewährleisten, die bei Überschreiten der kritischen Heizflächenbelastung aufschmelzen bzw. reißen können. Aus diesem Grund werden im Rahmen eines vom Bundesministerium für Bildung und Forschung geförderten Projektes (Förderkennzeichen 02NUK010A) numerische Strömungsberechnungsmodelle entwickelt, die bei der Beschreibung und numerischen Behandlung der Siedephänomene helfen sollen. Zur Validierung dieser Modelle anhand von Experimenten wurde ein Strömungskanal konstruiert, in dem ein vertikales Stabbündel von einem Kältemittel (RC318) aufwärtig durchströmt wird. Der Versuchsstand ist so konzipiert, dass ein optischer und messtechnischer Zugang zu den umströmten Einbauten gegeben ist. Damit sind Messungen in Zweiphasenströmungen ebenso möglich, wie Untersuchungen zur einphasigen Durchströmung. Für später erfolgende Zweiphasen-Experimente mit Stabbeheizung wurden zunächst Voruntersuchungen zur einphasigen Durchströmungen durchgeführt, welche insbesondere Aufschluss über die Homogenität der Strömung in den Unterkanälen sowie die Existenz von Querströmungen geben sollten. Als Messverfahren dafür wurde die Particle Image Velocimetry (PIV) ausgewählt, welche es ermöglicht, zweidimensionale Strömungsfelder aufzuzeichnen. Die experimentellen Studien erfolgten am Optical Multi-Phase Flow Research Laboratory des Nuclear Engineering Department der Texas A&M University in College Station, USA. Die Untersuchungen wurden für drei Volumenstromraten durchgeführt. Der vorliegende Bericht umfasst die Beschreibung des Versuchsstandes und der Messmethodik, eine Vorstellung des Auswerteverfahrens und relevanter Ergebnisse sowie eine Fehlerbetrachtung.

Ever-increasing interest in millimeter-wave and terahertz spectrum has prompted research and development of novel passive components working at these frequencies. Compared with the conventional planar components, non-planar dielectric devices become more attractive as frequencies increase due to their higher quality factors and dimensional tolerances. In this thesis, we present fast methods to analyze the millimeter-wave dielectric resonator and rod antenna. First, an analytical method has been developed to evaluate resonant frequencies, quality factors of the Whispering Gallery Mode (WGM) disk resonators and also the resonator-waveguide coupling. A numerical solver based on full-wave finite element method is implemented to verify the analytical result. This analytical model provides a solution for fast design and optimization of WGM resonators in filter and sensor applications. Secondly, a fast analytical approach based on local mode theory is introduced to calculate the radiation from tapered dielectric rod antenna. This efficient approximate model consumes much less computing resources and time, and demonstrates good agreements with full-wave numerical results. It supplies a quantitative way to understand the radiation mechanism and interaction between different parts of the antenna. Based on this, design criteria for the taper profile of rod antennas are given.

In a nuclear power plant, control rods play a central role to control the reactivity ofthe core. In an inspection campaign of three control rods (CR 99) operated in theKKL reactor in Leibstadt, Switzerland, during 6 respectively 7 consecutive cycles,defects were detected in the top part of the control rods due to swelling caused bydepletion of the neutron-absorbing 10B isotope (Boron-10). In order to correlatethese defects to control rod depletion, the 10B depletion has in this study beencalculated in detail for the absorber pins in the top node of the control rods.Today the core simulator PLOCA7 is used for predicting the behavior of the reactorcore, where the retrievable information from the standard control rod follow-up isthe average 10B depletion for clusters of 19 absorber holes i.e. one axial node.However, the local 10B depletion in an absorber pin may be significantly differentfrom the node average depletion that is re-ceived from POLCA7. To learn more, the 10B depletion has been simulated for each absorber hole in the uppermost node usingthe stochastic Monte Carlo 3D simulation code MCNP as well as an MCNP- based2D-depletion code (McScram). It was found that the 10B depletion is significantly higher for the uppermost absorberpins than the node average. Furthermore, the radial depletion in individual absorberpins was found to be much higher than expected. The results are consistent with theexperimental data on control rod defects.

Ever-increasing interest in millimeter-wave and terahertz spectrum has prompted research and development of novel passive components working at these frequencies. Compared with the conventional planar components, non-planar dielectric devices become more attractive as frequencies increase due to their higher quality factors and dimensional tolerances. In this thesis, we present fast methods to analyze the millimeter-wave dielectric resonator and rod antenna. First, an analytical method has been developed to evaluate resonant frequencies, quality factors of the Whispering Gallery Mode (WGM) disk resonators and also the resonator-waveguide coupling. A numerical solver based on full-wave finite element method is implemented to verify the analytical result. This analytical model provides a solution for fast design and optimization of WGM resonators in filter and sensor applications. Secondly, a fast analytical approach based on local mode theory is introduced to calculate the radiation from tapered dielectric rod antenna. This efficient approximate model consumes much less computing resources and time, and demonstrates good agreements with full-wave numerical results. It supplies a quantitative way to understand the radiation mechanism and interaction between different parts of the antenna. Based on this, design criteria for the taper profile of rod antennas are given.