Essa dissertação aborda o tema de propagação de ondas de tensão em hastes metálicas retangulares. Este tipo de onda pode ser utilizada como base na verificação da integridade estrutural através de um ensaio não destrutivo (END). A propagação de ondas elásticas em sólidos apresenta muito potencial quando se deseja estimar a integridade de determinada estrutura. Porém para transformar esse fenômeno físico em uma técnica aplicável na detecção de danos, alguns passos devem ser seguidos, dentre eles: a compreensão das características de propagação da estrutura em estudo, in teração das ondas elásticas com defeitos, aten uação das ondas propagadoras devido a fontes de amortecimento e dispersão. Neste contexto o presente trabalho tem o principal foco no desenvolvimento de uma metodologia eficiente para a investigação da propagação de ondas de tensão em hastes retangulares metálicas, abordando o tema por diversos aspectos. No decorrer do mesmo são calcu ladas as curvas de dispersão de uma haste retangular com seção transversal de 15 x5 [rum], para uma faixa de frequência determinada [0,100 kHz], utilizando três metodologias distintas e realizando a comparação crítica entre elas. São realizadas investigações teóricas, de forma analítica e numérica (via análise explícita empregando elementos finitos) e uma inves tigação experimental das características de propagação da geometria referida. Também os efeitos da aten uação das ondas na geometria é estudado. Os resulta dos obtidos são discutidos procurando mostrar sua coerência e enfatizando a informação sobre o comportamento mecânico das ondas de tensão nesse tipo de estrutura, observando aspectos relevantes à concepção de técnicas de END que possi bilitem a avaliação da integridade dessas estruturas. / This dissertation addresses the issue of propagation of stress waves in metallic rectangular rods. This type of wave can be used as the integrity check structural integrity through a non-destructive test (NDT). The propagation of elastic waves in solids has a lot of potential when estimating the given structure integrity. But to turn this physical phenomenon in an applicable technique for the detection of damage, some steps should be taken, including: understanding of propagating characteristics of the structure under study, interaction of elastic waves with defects, attenuation of the propagating waves due to sources of damping and dispersion. In this context, the present work is the main focus in developing an effective methodology for investigating the propagation of stress waves in rectangular metal rods, addressing the issue by several aspects. During the same are calculated dispersion curves of a rod with rectangular cross section 15 x5 [mm], for a given frequency range [0,100 kHz], using three different methodologies and performing the critical comparison between them. Are performed theoretical investigations, in analytical and numerical form (via explicit analysis using finite element) and an experimental investigation of the propagation features said geometry. Also the effects of attenuation of the waves on geometry is studied. The results are discussed trying to show their consistency and emphasizing information about the mechanical behavior of stress waves in this type of structure, observing relevant aspects to the design of NDT techniques to enable the assessment of the integrity of these structures.

Une analyse numérique basée sur la méthode des éléments finis permettant de quantifier les coefficients d'atténuation et de diffusion ultrasonores dans un polycristal en domaine temporel et fréquentiel est présentée. En particulier, une méthode originale basée sur le théorème de réciprocité pour l'évaluation numérique du coefficient de diffusion est proposée. Des formules analytiques bidimensionnelles (2D) pour les coefficients d'atténuation ultrasonore et de rétrodiffusion sont développées en utilisant l'approximation de Born pour valider les évaluations numériques. L'approche numérique proposée est appliquée au titanium, un polycristal monophasé et non texturé. Premièrement, des simulations sont effectuées dans des microstructures idéalisées composées de grains en taille unimodale. Une comparaison cohérente entre les évaluations numériques et les prédictions analytiques 2D est obtenue. Par ailleurs, les effets de l'atténuation induite par la diffusion multiple sur la mesure de rétrodiffusion, qui sont négligés par les modèles théoriques, sont quantifiés. Deuxièmement, l'approche numérique proposée est appliquée aux polycristaux composés de grains en taille bimodale. Les résultats numériques indiquent que les coefficients d'atténuation et de rétrodiffusion en domaine fréquentiel se situent au milieu des coefficients pour les microstructures unimodales et sont principalement déterminés par les fractions volumiques des grains constitutifs. Cependant, ils ne sont que légèrement affectés par la répartition des gros grains. Une étude de la fonction d'autocorrélation spatiale dans des telles microstructures bimodales est proposée afin d’obtenir une interprétation analytique des phénomènes expérimentés numériquement. / A numerical approach based on the finite element method to quantify ultrasonic attenuation and grain-noise scattering coefficients in both time and frequency domains for polycrystalline materials is presented. More particularly, an original method based on the reciprocity theorem for the numerical evaluation of the grain-noise scattering coefficient is proposed. Twodimensional (2D) analytical formulas of ultrasonic attenuation and backscattering coefficients are developed by using the Born approximation to validate numerical evaluations. Then the proposed numerical approach is applied to the single-phase and untextured polycrystalline titanium. Firstly, 2D FE simulations are performed in idealized microstructures composed of equiaxed grains with different unimodal grain sizes. Coherent comparison between numerical estimates and 2D analytical predictions is obtained. Effects of attenuation due to multiple scattering on the backscattering measurement, which are neglected in the theoretical model, are quantified. Secondly, polycrystals with bimodal grain sizes are considered. Numerical results indicate that attenuation and backscattering coefficients in bimodal microstructures are inbetween the ones of unimodal microstructures and are mainly determined by volume fractions of the constituent grains. However they are only slightly affected by the grain location distributions. The spatial autocorrelation function in bimodal microstructures is further quantified to gain an analytical interpretation of the above phenomena.

Este estudo trata da manifestação da cortesia verbal nas interações feitas por e-mail dentro de ambientes empresariais espanhóis e brasileiros. Buscamos, por meio da análise quantitativa de um corpus composto por correios eletrônicos em Português e em Espanhol, diferenças e/ou semelhanças entre as duas línguas e culturas na forma de comunicar-se por este meio. Em primeiro lugar, discutimos conceitos básicos sobre o gênero discursivo de nosso corpus e, em seguida, passamos às primeiras comparações entre as línguas a este respeito. Com base, principalmente, nos estudos da Pragmática sociocultural, autonomia/afiliação (Bravo, 1999) e atenuação (Briz, 1998), verificamos os pedidos emitidos por brasileiros e espanhóis. Buscamos, em nossas análises, encontrar diferenças e/ou semelhanças linguísticas e socioculturais no que diz respeito a estes atos de fala, traçando uma relação com os estudos da cortesia verbal. Verificamos também a frequência e função dos marcadores de atenuação nessas interações via e-mail. Nossos resultados demonstram algumas diferenças e semelhanças nas formas de interação dessas línguas. Parece haver uma valorização, por parte do Português do Brasil, de uma cortesia atenuadora, que visa a diminuir o grau de imposição de um pedido, evitando, desse modo, um possível desequilíbrio entre os interlocutores. O mesmo não ocorre no grupo de e-mails representantes do Espanhol peninsular. Percebemos que, ainda que sejam línguas semelhantes do ponto de vista estrutural, existem diferenças pragmáticas durante suas interações por e-mail / This study is about the presence of linguistic politeness in Brazilian and Spanish corporate e-mails. Applying a quantitative research technique in a corpus composed by electronic mails in Brazilian Portuguese and Peninsular Spanish, we searched for differences and/or similarities between both languages and cultures in the way of communicating via e-mails. Firstly, we discussed basic concepts about the discursive genre we used as our corpus. Following, we compared both languages regarding those concepts. Based, mainly, on sociocultural pragmatics, autonomy/affiliation (Bravo, 1999), and attenuation (Briz, 1998) studies, we analyzed Brazilian and Spanish requests. We tried to identify linguistic and sociocultural contrasts and similarities in the way of communicating written requests. We also verified the frequency and role of attenuation marks within these e-mails. Our results demonstrated some variation and resemblance in how both languages communicate requests. It seems that there is an over appreciation from the Brazilian Portuguese side, for using attenuators, in order to diminish the degree of imposition of a request, and therefore avoiding a possible instability between the interlocutors. This preference does not occur among the Spanish e-mail group. We found out that, although they are similar languages, their pragmatic choices in e-mail interaction do not seem to coincide

Submitted by Joana Azevedo (joanad@id.uff.br) on 2017-07-03T12:52:37Z No. of bitstreams: 1 Dissert CEZAR AUGUSTO CECHIN.pdf: 2893279 bytes, checksum: 6041ec6c989e858605c656ff1fe6baab (MD5) / Approved for entry into archive by Biblioteca da Escola de Engenharia (bee@ndc.uff.br) on 2017-07-06T16:47:06Z (GMT) No. of bitstreams: 1 Dissert CEZAR AUGUSTO CECHIN.pdf: 2893279 bytes, checksum: 6041ec6c989e858605c656ff1fe6baab (MD5) / Made available in DSpace on 2017-07-06T16:47:06Z (GMT). No. of bitstreams: 1 Dissert CEZAR AUGUSTO CECHIN.pdf: 2893279 bytes, checksum: 6041ec6c989e858605c656ff1fe6baab (MD5) Previous issue date: 2016-06-20 / Esta pesquisa apresenta como objetivo geral analisar o controle de ruído nos geradores de energia em uma balsa guindaste, através da utilização de materiais de atenuação, intervenção na vibração dos equipamentos e na introdução de acessórios e componentes de máquinas, ventiladores e exaustores. Para o desenvolvimento da pesquisa foi escolhida um dos ambientes de trabalho mais ruidosos da balsa guindaste, construída na década de 70, pertencente a uma das Empresas que presta apoio na exploração e produção de petróleo na área de Engenharia Submarina e que seu escopo principal é realizar atividades de movimentação de grandes cargas e lançamentos de dutos. Numa avaliação detalhada nas frentes de serviço e dos equipamentos existentes, medições e estudos realizados no período 2013 até 2016, histórico de monitoramento dos ruídos e análise critica dos últimos cinco anos, bem como entrevista verbal com a força de trabalho envolvida, foram selecionados a praça de geradores de energia para estudo de caso e melhorias na atenuação do ruído. Conjuntamente com a implantação das medidas propostas de redução de ruído, foi aplicado o questionário para verificação da eficácia do tratamento realizado e dos fatores de qualidade de vida dos colaboradores. Como resultado final foi sugerido às medidas corretivas e preventivas para tornar o ambiente saudável do ponto de vista da higiene ocupacional, como por exemplo, a instalação de atenuadores de ruído nos ventiladores e exaustores dos geradores de energia, instalação de painéis de lã de rocha com chapas perfuradas em determinados ambientes, bem como inserir forro acústico no teto da sala e paredes da sala de manutenção (SMM), visando diminuir a influencia das fontes geradoras. / The present research intends to analyze the noise control in power generators on a ferry crane, through the use of mitigation materials, intervention in the equipment’s vibration and the introduction of accessories and machine components, ventilation fans and exhaust fans. In order to develop this research it was chosen one of the noisiest barge crane, which was built in the 1970s, owned by one of the companies that provide support in oil exploration and production in the field of Subsea Engineering and its main goal is to perform activities that handle with large loads and pipelines launching. In a detailed evaluation of the service and equipment, measurements and studies of the noise monitoring historical and critical analysis of the past five years were realized during 2013 to 2016, as well as verbal interviews with the workforce involved, selecting some square power generators for case study and improvements in noise attenuation. In conjunction with the implementation of noise reduction measures proposed, it was applied a questionnaire to verify the effectiveness of the treatment and the quality of life of employees factors. As a final result it was suggested to the corrective and preventive measures to turn it into a healthy area from the point of view of occupational hygiene, such as the installation of noise attenuators in ventilation fans and exhaust fans of power generators, installation of rock wool panels with perforated sheets in certain areas, as well as insert acoustic ceiling in the living room and walls of the engine room monitoring, in order to reduce the influence of the generating sources.

Este trabalho sustenta que o processo de cooperação para manutenção das faces é condição principal numa interação não polêmica. Esse processo aparece marcado na materialidade linguística, e, quando um ato que ameaça à face é produzido por um dos participantes da interação, em regra, segue acompanhado por procedimentos atenuadores que visam a minorar a ameaça e minimizar os danos causados à imagem dos participantes. O objetivo geral desta pesquisa é investigar o uso dos procedimentos de atenuação como parte do processo de cooperação para preservação da face em interações não polêmicas. Foram gravadas três entrevistas, no total de cinco horas e cinquenta e um minutos e vinte e sete segundos. Tais entrevistas foram separadas em três modalidades: modalidade 1 subdividida em 1A e 1B; modalidade 2 e modalidade 3 subdividida em 3A, 3B e 3C. Para as análises do corpus, utilizamos a noção de face constantes em Goffman (1980), em Brown e Levinson (1987), bem como os estudos sobre cortesia de Bravo (2005), e as definições de atenuação de Briz Goméz (2004, 2005, 2012) e Albelda Marco (2014). Os resultados mostraram que os procedimentos linguísticos empregados serviram em algumas falas para proteger ou reparar algum dano à imagem do falante e em outras para preservar ou reparar a imagem do ouvinte e também preservar ou reparar a imagem de ambos. Os interlocutores procuraram evitar o conflito e colaborar para que as imagens fossem resguardadas. Concluímos que os procedimentos de atenuação possibilitaram aos falantes afastarem-se do conteúdo dos enunciados, quando esses representaram um ameaça e, ao mesmo tempo, aproximarem-se dos ouvintes, cooperando para a preservação das faces, evitando o conflito na interação. / This study argues that the cooperation process for the maintenance of faces is the main requirement in a non-polemic interaction. This process is marked in linguistic materiality and when an act that threatens the face is produced by one of the participants of the interaction, as a rule, occur a procedure of attenuation that aim to mitigate a threat and minimize the damage caused to the image of the participants. The general objective of this research is to investigate attenuation´s procedure as part of the cooperation process for the preservation of the face in non-controversial interactions. Three interviews were recorded with total amount of time being five hours and fifty-one minutes and twenty-seven seconds. These interviews were divided into three types: category 1 subdivided into 1A and 1B; Category 2 and category 3 subdivided in 3A, 3B and 3C. For the analysis of the corpus we use the Goffman\'s notion of face (1980) Brown and Levinson (1987), as well as the studies on politeness of Bravo (2005), and the definitions of attenuation of Briz Goméz (2004, 2005, 2012) and Albelda Marco (2014). The results showed that linguistic procedures can be used to protect or repair some damage of the speaker´s image, the listener´s image or the image of both. The interlocutors tried to avoid conflict and to collaborate so the images would remain the same. We concluded that attenuation procedure might allow speakers to keep some distance from the discussed topic when it may represent a threat and at the same time approach to listeners, cooperating with them for the preservation of faces, avoiding conflict when interacting.

Esta dissertação estuda o controle multivariável de uma plataforma \"offshore\" típica. Com esse propósito, um modelo dinâmico rigoroso do processo não-linear foi desenvolvido e usado para representar o processo real nas simulações das estratégias de controle propostas. Baseado no modelo rigoroso e usando métodos de identificação, foram desenvolvidos modelos lineares aproximados para representar o processo no controlador preditivo (MPC). O sistema de controle foi projetado visando manter as variáveis controladas em valores adequados e reduzir o efeito de golfadas severas nos equipamentos à jusante da plataforma. Foram testados dois controladores preditivos: o MPC convencional que opera com \"setpoints\" fixos para as variáveis controladas e o controlador preditivo que opera com zonas para as variáveis controladas. Os resultados da simulação mostram que o controlador preditivo com controle por zonas é capaz de ter uma performance bem melhor que o controlador preditivo convencional, com uma significativa redução na amplitude das oscilações causadas pelas golfadas na vazão de petróleo na saída da plataforma. / This dissertation studies the multivariable control of a typical offshore platform. For this purpose, a rigorous nonlinear dynamic model of the process system is developed and used to represent the true process in the simulation of the proposed control strategies. Based on this rigorous model, approximate linear models are obtained through identification methods in order to represent the platform process in the Model Predictive Control (MPC). The control system was designed aimed at keeping all the controlled variables at adequate values and to reduce the effect of severe riser slugging on the downstream systems. Two model predictive controllers are tested: the conventional MPC with fixed set-points to the controlled outputs and the MPC with zone control of the outputs. The simulation results show that the controller based on the output zone control has a better performance than the conventional MPC with a significant reduction on the amplitude of the oscillation of oil flow at the outlet of the platform process.

As propriedades de espalhamento de raios X e atenuação de tecidos mamários normais (adiposo e fibroglandular), neoplásicos (benigno e maligno) e vários materiais tecido-equivalente (nylon, poliacetato, polimetilmetacrilato (PMMA), água, músculo-equivalente, osso-equivalente e adiposo-equivalente) foram determinados usando um sistema de raios X dispersivo em energia (SRXDE). O SRXDE consistiu de um tubo de raios X com anodo de tungstênio operando a 60kVp, um goniômetro e dois detectores: um detector de telureto de cádmio (CdTe), posicionado a 7 graus com relação ao feixe incidente usado para detectar a distribuição em energia dos fótons espalhados (numa faixa de momento transferido de 0,5nm-1 - 3,5nm-1) e um detector de silício (Silicon Drift Detector, SDD), posicionado a zero graus e usado para detectar a distribuição em energia do feixe transmitido (com amostra) ou do feixe incidente (sem amostra). A distribuição espectral foi processada para se obter o perfil de espalhamento e o coeficiente de atenuação linear de 100 amostras de tecidos mamários (59 normal, 30 maligno e 11 benigno). Este sistema foi, também, aplicado ao estudo de regiões de transição entre tecidos com diferentes composições. Os resultados encontrados neste trabalho mostram que os tecidos mamários podem ser caracterizados através de suas propriedades de atenuação e espalhamento. Perfis de espalhamento neoplásico apresentam formato do pico principal significativamente diferente na faixa de momento transferido de 0,8nm-1 - 2,0nm-1, aos tecidos normais. Especificamente, o tecido adiposo apresentou um perfil de espalhamento muito diferente (pico principal em 1,12nm-1 e LMA de 0,33nm-1) quando comparado com tecidos neoplásico maligno e benigno e normal fibroglandular (pico principal em torno de 1,54nm-1 e LMA em torno de 0,73nm-1). O coeficiente de atenuação linear observado para os tecidos maligno, benigno e fibroglandular são muito similares e mostraram diferenças menores que 8% para energias entre 10 e 35keV. Entretanto, o tecido adiposo apresentou diferenças significativas com relação aos outros tecidos em toda faixa de energia (diferenças de até 40% foram observadas). Os resultados obtidos da varredura espacial das amostras heterogêneas mostram que o sistema desenvolvido permite o estudo de regiões de transição entre tecidos com diferentes composições. Finalmente, nossos resultados foram comparados com dados experimentais previamente publicados na literatura, mostrando boa concordância dentro das incertezas estatísticas. / The X-ray scattering and attenuation properties for normal (adipose and glandular) and neoplastic (benign and malignant) breast tissues and several tissue-equivalent materials (nylon, polyacetate, polymethylmethacrylate (PMMA), water, muscle-equivalent, bone-equivalent and adipose-equivalent) were determined using an energy dispersive X-ray system (EDXS). The EDXS consisted of a tungsten anode X-ray tube operating at 60kVp, a goniometer, and two detectors: a Cadmium Telluride (CdTe) detector, positioned at 7 degrees with relation to the incident beam used for detecting the energy distribution of scattered photons (over the momentum transfer range of 0,5nm-1- 3,5nm-1) and a Silicon Drift Detector (SSD), positioned at zero degree used for detecting the energy distribution of the transmitted beam (with the sample) or the incident beam (without the sample). The spectra distributions were processed to obtaine the scattering profile and the linear attenuation coefficient of 100 samples of breast tissues (59 normal, 30 malignant and 11 benign). This system was also applied to the study of the transition regions between tissues with different composition. The results found in this work show that breast tissues may be characterized through their attenuation and scattering properties. Neoplastic scattering profiles presented format and the main peak position significantly different in the range of momentum transfer from 0,8nm-1- 2,0nm-1, to normal tissues. Specifically, adipose tissue presented a very different scattering profile (main peak at 1,12nm-1and FWHM of 0,33nm-1) when compared with malignant, benign and also normal glandular tissues (main peak around 1,54nm-1and FWHM about of 0,73nm-1). The linear attenuation coefficient observed for malignant, benign and normal glandular tissues were quite similar and showed differences smaller than 8% for energies between 10 and 35keV. However, adipose tissue presented significant differences from the others tissues type in all energy range (differences up to 40% were observed). The results of the spatial scan of heterogeneous samples show that the developed system allows the study of transition regions between tissues with different composition. Finally, our results were compared with previous experimental data showing a good agreement within the experimental uncertainties

For this study, we revisited whether the common iron Fe mineral, magnetite Fe3O4 (s), can reduce tetrachloroethylene (PCE) and trichloroethylene (TCE) as discrepancies exist in the literature regarding rates and extent of reduction. We measured PCE and TCE reduction in batch reactors as a function of magnetite stoichiometry (x = Fe2+/Fe3+ ratio), solids loading, pH, and Fe(II) concentration. Our results show that magnetite reacts only slowly with TCE (t1/2 = 7.6 years) and is not reactive with PCE over 150 days. The addition of aqueous Fe(II) to magnetite suspensions, however, results in slow, but measurable PCE and TCE reduction under some conditions. The solubility of ferrous hydroxide, Fe(OH)2(s), appears to play an important role in whether magnetite reduces PCE and TCE. In addition, we found that Fe(OH)2(s) reduces PCE and TCE at high Fe(II) concentrations as well. At certain conditions degradation of the PCE and TCE is enhanced by an unexplored synergistic response from magnetite and ferrous hydroxide iron phases. Our work suggests that measuring dissolved Fe(II) concentration and pH may be used as indicators to predict whether PCE and TCE will be abiotically degraded by groundwater aquifer solids containing magnetite.

L’atténuation sismique est un paramètre physique très utile pour décrire et imager les propriétés du sous-sol, et tout particulièrement les roches saturées et les nuages de gaz. Les approches classiques analysent l’amplitude du spectre des données ou bien la distorsion de ce spectre, avec des méthodes asymptotiques. L’inversion des formes d’onde (Full Waveform Inversion en anglais, FWI) est une approche alternative qui prend en compte les aspects de fréquences finies. En pratique, à la fois les vitesses et l’atténuation doivent être déterminées. Il est connu que l’inversion multi-paramètre ne conduit pas à un résultat unique.Ce travail se focalise sur la détermination des vitesses et de l’atténuation. La dispersion liée à l’atténuation produit des modèles de vitesse équivalents en termes de cinématique. Je propose une inversion hybride : la « relation cinématique » est un moyen de guider l’inversion des formes d’onde non-linéaire. Elle se décompose en deux étapes. Dans un premier temps, l’information cinématique est remise à jour, et ensuite les vitesses et l’atténuation sont modifiées, pour une cinématique donnée. Différentes approches sont proposées et discutées au travers d’applications sur des données synthétiques 2D, en particulier sur les modèles Midlle-East et Marmousi. / Seismic attenuation is a useful physical parameter to describe and to image the properties of specific geological bodies, e.g., saturated rocks and gas clouds. Classical approaches consist of analyzing seismic spectrum amplitudes or spectrum distortions based on ray methods. Full waveform inversion is an alternative approach that takes into account the finite frequency aspect of seismic waves. In practice, both seismic velocities and attenuation have to be determined. It is known that the multi-parameter inversion suffers from cross-talks.This thesis focuses on retrieving velocity and attenuation. Attenuation dispersion leads to equivalent kinematic velocity models, as different combinations of velocity and attenuation have the same kinematic effects. I propose a hybrid inversion strategy: the kinematic relationship is a way to guide the non-linear full waveform inversion. The hybrid inversion strategy includes two steps. It first updates the kinematic velocity, and then retrieves the velocity and attenuation models for a fixed kinematic velocity. The different approaches are discussed through applications on 2D synthetic data sets, including the Midlle-East and Marmousi models.

Networks of small, often mobile, polarimetric radars are gaining popularity in the hydrometeorology community due to their rainfall observing capabilities and relative low purchase cost. In recent years, a number of installations have become operational around the globe. The problem of signal attenuation by intervening rainfall has been recognized as the major source of error in rainfall estimation by short-wavelength (C-, X, K-band) radars. The simultaneous observation of precipitation by multiple radars creates new prospects for better and more robust attenuation correction algorithms and, consequently, yields more accurate rainfall estimation. The University of Iowa hydrometeorology group's acquisition of a network of four mobile, polarimetric, X-band radars has resulted in the need for a thoughtful evaluation of the instrument. In this work, we use computer simulations and the data collected by The University of Iowa Polarimetric Radar Network to study the performance of attenuation correction methods in single-radar and network-based arrangements. To support the computer simulations, we developed a comprehensive polarimetric radar network simulator, which replicates the essential aspects of the radar network rainfall observing process. The simulations are based on a series of physics- and stochastic-based simulated rainfall events occurring over the area of interest. The characteristics of the simulated radars are those of The University of Iowa Polarimetric Radar Network. We assess the correction methods by analyzing the errors in reflectivity and rainfall rate over the area of interest covered by the network's radars. To enable the implementation of the attenuation correction methods to the data collected by The University of Iowa Polarimetric Radar Network, we first developed a set of utilities to assist with efficient data collection and analysis. Next, we conducted a series of calibration tests to evaluate the relative calibration and channel balance of the 2 network's radars. Finally, in an attempt to verify the results obtained via computer simulations, we applied the set of attenuation correction algorithms to the data collected by The University of Iowa Polarimetric Radar Network.