Les matériaux absorbants électromagnétiques, ou « Radar Absorbing Materials » (RAM), ont été créés à la fois aux USA et en Allemagne lors de la seconde guerre mondiale. Les applications des absorbants appartiennent principalement aux domaines de la Compatibilité ElectroMagnétique (CEM) et de la discrétion radar. Ces absorbants sont lourds et encombrants. Au travers de cette thèse, nous cherchons à développer une solution pour pallier à ces inconvénients grâce aux absorbants à métamatériaux. Les métamatériaux sont des composites artificiels présentant des propriétés électromagnétiques que l'on ne retrouve pas dans la nature. En utilisant ce type de matériaux, nous pouvons obtenir des absorbants ultras fins, et par l'optimisation et la conception couvrir des bandes larges en fréquence. Nous proposons donc plusieurs formes basiques d'absorbant à métamatériaux. De ces formes, nous présentons un modèle théorique et développons les techniques pour définir leur fréquence de fonctionnement et les paramètres nécessaires pour obtenir une absorption totale. Puis nous étudions plus en détail nos différents prototypes à travers des simulations et des mesures. Nous étudions aussi le couplage des absorbants à métamatériaux avec des absorbants traditionnels pour créer un type d'absorbant inédit. / Electromagnetic absorbing materials, or "Radar Absorbing Materials" (RAM), were created in the U.S. and Germany at the same time during the Second World War. Applications of absorbers are mainly in the field of ElectroMagnetic Compatibility (EMC) and radar stealth. These absorbers are heavy and bulky. In this thesis, we seek to develop a solution to overcome these drawbacks using metamaterial absorbers. Metamaterials are artificial composites with electromagnetic properties that are not found in nature. By using this type of material, we can obtain ultra-thin absorbers over a wide band of frequency by optimizing the design. We introduce several basic forms of metamaterial absorbers. From these geometries, we present a theoretical model and we develop techniques to define their operating frequency and parameters required to achieve total absorption. Then we study in detail our various prototypes with simulations and measurements. We also study the coupling of metamaterial absorbers with traditional ones to create a new type of absorber.

abstract: Attaining a sufficiently large critical current density (Jc) in magnetic-barrier Josephson junctions has been one of the greatest challenges to the development of dense low-power superconductor memories. Many experimentalists have used various combinations of superconductor (S) and ferromagnetic (F) materials, with limited success towards the goal of attaining a useful Jc. This trial-and-error process is expensive and time consuming. An improvement in the fundamental understanding of transport through the ferromagnetic layers and across the superconductor-ferromagnetic interface could potentially give fast, accurate predictions of the transport properties in devices and help guide the experimental studies. In this thesis, parameters calculated using density functional methods are used to model transport across Nb/0.8 nm Fe/Nb/Nb and Nb/3.8 nm Ni /Nb/Nb Josephson junctions. The model simulates the following transport processes using realistic parameters from density functional theory within the generalized gradient approximation: (a) For the first electron of the Cooper pair in the superconductor to cross the interface- conservation of energy and crystal momentum parallel to the interface (kll). (b) For the second electron to be transmitted coherently- satisfying the Andreev reflection interfacial boundary conditions and crossing within a coherence time, (c) For transmission of the coherent pair through the ferromagnetic layer- the influence of the exchange field on the electrons’ wavefunction and (d) For transport through the bulk and across the interfaces- the role of pair-breaking from spin-flip scattering of the electrons. Our model shows the utility of using realistic electronic-structure band properties of the materials used, rather the mean-field exchange energy and empirical bulk and interfacial material parameters used by earlier workers. [Kontos et al. Phys. Rev Lett, 93(13), 137001. (2004); Demler et al. Phys. Rev. B, 55(22), 15174. (1997)]. The critical current densities obtained from out model for Nb/0.8 nm Fe/Nb is 104 A/cm2 and for Nb/3.8 nm Ni/Nb is 7.1*104 A/cm2. These values fall very close to those observed experimentally- i.e. for Nb/0.8 nm Fe/Nb is 8*103 A/cm2 [Robinson et al" Phys. Rev. B 76, no. 9, 094522. (2007)] and for Nb/3.8 nm of Ni/Nb is 3*104 A/cm2 [Blum et al Physical review letters 89, no. 18, 187004. (2002). This indicates that our approach could potentially be useful in optimizing the properties of ferromagnetic-barrier structures for use in low-energy superconducting memories. / Dissertation/Thesis / Masters Thesis Materials Science and Engineering 2018

Research has shown that effective school leadership has a positive influence on school effectiveness and student achievement. Current reform efforts include teachers, both formally and informally, as leaders of schools. However, there are currently no widely-accepted measurements or models to assess both formal and informal teacher leadership in schools. The purpose of this study was to compare model fit for the four-factor model of teacher leadership to model fit for three alternative models. The four-factor model was developed during the second administration of the Teacher Leadership Inventory (TLI), and the three alternative models were developed from the results and recommendations from the confirmatory factor analysis of that administration. Teacher responses to the second administration of the TLI constituted the data set for this study. Participants included 421 teachers from 23 schools in three East Tennessee school districts. Confirmatory factor analyses were conducted for each of the measurement models under investigation, and model fit indices and parameter estimates of all four models were used for comparison. Model fit indices indicate better model fit for the four-factor model over both the two-factor and five-factor models but not over the three-factor model. However, further evaluation of both parameter estimates and prior research provide support for the acceptability of the four-factor model over the three-factor model.

This study addresses the need for a parsimonious theoretical model to explain state-corporate crime. The Integrated Theoretical Model of State-Corporate Crime will be compared to the Integrated Theory of International Criminal Law Violation to determine which model provides the most accurate theoretical depiction of state- corporate crime, while retaining parsimony. For this comparison, the models will be applied to Democratic Republic of Congo case study. Using a secondary analysis of qualitative data and preexisting literature, it was found that the Integrated Theoretical Model of State-Corporate Crime displays a representative depiction of all state-corporate crime actors and their catalysts for action in a more parsimonious manner than the Integrated Theory of International Criminal Law Violation.

Multimode devices play an increasingly important role in both communication and sensing systems. Mode division multiplexing (MDM) in multimode fiber (MMF) is becoming a promising method to further increase the capacity of optical transmission link with a controllable mode coupler. Similarly, optic sensors based on core-cladding-mode interference can be widely used in measurement of refractive index (RI), temperature and strain. Fiber Bragg gratings (FBGs) in single mode operation have been extensively studied as in-line optical components for both communication and sensing applications. In recent years, research has been extended to FBGs in few-mode operation as mode couplers in MDM applications. Experimentally, mode conversion from fundamental linear polarization (LP) mode LP01 to higher order LP11 mode in two-mode FBG (TMFBG) has been observed. Index asymmetry and electric field distortion induced by ultraviolet (UV) side illumination in fabrication of FBG make the two modes no longer orthogonal. However, its spectrum analysis mainly depends on experimental data and software simulation using the complex finite element method (FEM). Here a simpler theoretical model based on coupled mode theory (CMT) and Runge-Kutta method (RKM) is proposed. An analytical expression of the mode coupling coefficient is derived and the modeling results match very well with experimental data. Abrupt fiber tapers allow power transfer between core and cladding modes and show promise as RI sensing components when two abrupt tapers are cascaded into an in-line Mach-Zehnder interferometer (MZI). The main advantage of the MZI taper sensor is its low manufacturing cost. However, the optical spectrum analyzer (OSA) used as the receiver and demodulation device in the conventional setup is still expensive. Three simplified schemes of fiber taper MZI RI sensor systems are designed and demonstrated experimentally. The transmitter and the demodulation devices for the three schemes are a single wavelength laser and a photodetector (PD), two modulated lasers and a PD together with data acquisition and processing module, and a broadband source (BBS) and a PD together with matched MZI, respectively. In all those implementations OSA is not required, which significantly lowers the cost and leads to easy integration. Although extra modulation/demodulation devices are required, the second implementation has the best performance. Automatic operation is realized by LabVIEW programming. High sensitivity (2371 mV/RI unit (RIU)) and high stability are achieved experimentally. Those new schemes have great potential to be applied to other interferometric optic sensor systems. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2014-05-09 11:44:44.837

Orientador: José Antônio Matthiesen / Banca: Renato Bertolino Junior / Banca: Francisco Antonio Rocco Lahr / Resumo: O Brasil é um país de forte vocação agrícola, que necessita lugares adequados para armazenagem de matérias subsidiárias, como por exemplo, óleos, detergentes, tintas, fertilizantes entre outros; de armazenagem de ferramentas, instrumentos, dispositivos, madeiras. As maiorias dos galpões são feitos de concreto, aço, madeira, porém existem aqueles chamados mistos. Com isso o projeto busca atender as necessidades de empresas que buscam poder armazenar seus fertilizantes em galpões feitos com madeira de reflorestamento, que é o Eucalipto Citriodora. A técnica construtiva aplicada pretende ter mais rapidez para que a estrutura fique pronta para o uso, além de economizar em mão-de-obra, materiais mais baratos e por fim, contribuindo para o uso sustentável da madeira no Brasil e procurando inspirar que não só aqui no Brasil e como vários lugares do mundo que é necessário que todos se conscientizem e preservem o "verde" do planeta. Será feito todo o estudo necessário para que este tipo de modelo, cujas dimensões para analise são de 5, 6 e 7,5 metros de comprimento, por 30 metros de largura e 15 metros de altura esteja de acordo com as normas. A estrutura terá uma série de pórticos, utilizando-se duas peças de madeira roliças para cada um deles e travadas em sua parte mais delgada através de uma ligação em forma de capuz metálico, formando um ângulo de 90o entre as peças. Para travar os 2 pórticos é utilizada uma peça roliça de madeira que usará conectores metálicos para fazer a ligação e estará posicionado a três quartos da altura do pórtico. Na base do poste há um tensionamento diminuindo o vão do pórtico de 31,5m para 30,0 m utilizando-se um cabo de aço e retirando-o quando colocado na base da fundação. Os cálculos teóricos da estrutura foram realizados seguindo as NBR 7190:1997 e NBR 6123:1988; e através de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Brazil is a country of strong agricultural vocation, which requires adequate sites for storage of subsidiary materials such as oils, detergents, paints, fertilizers, among others, storage of tools, instruments, appliances, wood. The majority of houses are made of concrete, steel, wood, however there are those called mixed. Thus the project aims to meet the needs of companies seeking to be able to store their fertilizers in sheds made of wood from reforestation, which is lemon eucalyptus. The construction technique used aims to have more speed for the structure to be ready for use, and saves on manpower, materials cheaper and ultimately contributing to the sustainable use of wood in Brazil and looking to inspire not only here in Brazil and how many places around the world that all must be aware and preserve the "green" the planet. It will be done all the studies required for this type of model to analyze the dimensions are 5, 6 and 7.5 meters long by 30 meters wide and 15 meters in height is consistent with the standards. The structure will have a series of frames, using two pieces of wood for each of them plump and locked in its thinnest part through a link-shaped metal hood, forming an angle of 90 ° between the parts. To lock the two frames is used a plump piece of wood that will use metal connectors to connect and be positioned at three-quarters of the height of the portico. At the base of the pole there is a tension reducing the span of the portico of 31.5 m to 30.0 m using a rope and pulling it while stationed at the foundation. Theoretical calculations of the structure were carried out using the NBR NBR 7190:1997 and 6123:1988, and by a numerical model developed in SAP2000 software, you can examine its behavior when subjected to proper weight and due to wind action. Concluding that it is not feasible to apply the tension and inclination of 30 ° is more appropriate, since the maximum span between frames is 6 feet. / Mestre

Made available in DSpace on 2014-06-11T19:25:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-21Bitstream added on 2014-06-13T20:32:48Z : No. of bitstreams: 1 pansiera_db_me_ilha.pdf: 3062626 bytes, checksum: adfa69acace77a9c80daa21019f26f63 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O Brasil é um país de forte vocação agrícola, que necessita lugares adequados para armazenagem de matérias subsidiárias, como por exemplo, óleos, detergentes, tintas, fertilizantes entre outros; de armazenagem de ferramentas, instrumentos, dispositivos, madeiras. As maiorias dos galpões são feitos de concreto, aço, madeira, porém existem aqueles chamados mistos. Com isso o projeto busca atender as necessidades de empresas que buscam poder armazenar seus fertilizantes em galpões feitos com madeira de reflorestamento, que é o Eucalipto Citriodora. A técnica construtiva aplicada pretende ter mais rapidez para que a estrutura fique pronta para o uso, além de economizar em mão-de-obra, materiais mais baratos e por fim, contribuindo para o uso sustentável da madeira no Brasil e procurando inspirar que não só aqui no Brasil e como vários lugares do mundo que é necessário que todos se conscientizem e preservem o “verde” do planeta. Será feito todo o estudo necessário para que este tipo de modelo, cujas dimensões para analise são de 5, 6 e 7,5 metros de comprimento, por 30 metros de largura e 15 metros de altura esteja de acordo com as normas. A estrutura terá uma série de pórticos, utilizando-se duas peças de madeira roliças para cada um deles e travadas em sua parte mais delgada através de uma ligação em forma de capuz metálico, formando um ângulo de 90o entre as peças. Para travar os 2 pórticos é utilizada uma peça roliça de madeira que usará conectores metálicos para fazer a ligação e estará posicionado a três quartos da altura do pórtico. Na base do poste há um tensionamento diminuindo o vão do pórtico de 31,5m para 30,0 m utilizando-se um cabo de aço e retirando-o quando colocado na base da fundação. Os cálculos teóricos da estrutura foram realizados seguindo as NBR 7190:1997 e NBR 6123:1988; e através de... / Brazil is a country of strong agricultural vocation, which requires adequate sites for storage of subsidiary materials such as oils, detergents, paints, fertilizers, among others, storage of tools, instruments, appliances, wood. The majority of houses are made of concrete, steel, wood, however there are those called mixed. Thus the project aims to meet the needs of companies seeking to be able to store their fertilizers in sheds made of wood from reforestation, which is lemon eucalyptus. The construction technique used aims to have more speed for the structure to be ready for use, and saves on manpower, materials cheaper and ultimately contributing to the sustainable use of wood in Brazil and looking to inspire not only here in Brazil and how many places around the world that all must be aware and preserve the green the planet. It will be done all the studies required for this type of model to analyze the dimensions are 5, 6 and 7.5 meters long by 30 meters wide and 15 meters in height is consistent with the standards. The structure will have a series of frames, using two pieces of wood for each of them plump and locked in its thinnest part through a link-shaped metal hood, forming an angle of 90 ° between the parts. To lock the two frames is used a plump piece of wood that will use metal connectors to connect and be positioned at three-quarters of the height of the portico. At the base of the pole there is a tension reducing the span of the portico of 31.5 m to 30.0 m using a rope and pulling it while stationed at the foundation. Theoretical calculations of the structure were carried out using the NBR NBR 7190:1997 and 6123:1988, and by a numerical model developed in SAP2000 software, you can examine its behavior when subjected to proper weight and due to wind action. Concluding that it is not feasible to apply the tension and inclination of 30 ° is more appropriate, since the maximum span between frames is 6 feet.

Made available in DSpace on 2014-06-11T19:31:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-06-19Bitstream added on 2014-06-13T21:02:49Z : No. of bitstreams: 1 nascimento_fr_dr_botfca.pdf: 1004832 bytes, checksum: 083eba73355a538dc2c9db45f95e6000 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A rede viária florestal influencia diretamente na qualidade do transporte. Ela serve de acesso às florestas, viabilizando o tráfego de mão de obra e o escoamento de matéria-prima. No entanto, uma das principais causas do aumento nos custos de construção é a má conservação e a falta de planejamento, visto que suas principais características são, muitas vezes, o baixo volume de tráfego e a utilização de veículos pesados e extrapesado. Além dos avanços tecnológicos e da importância do transporte para as empresas florestais, hoje, muitas empresas estão se preocupando com as condições ideais de rede viária florestal, principalmente no que se refere aos cuidados com planejamento e qualidade dos materiais utilizados. O objetivo deste trabalho foi propor e avaliar um modelo teórico de investimento para rede viária florestal em função do volume de madeira transportado. Verificou-se que os dados levantados em campo não eram compatíveis com o planejamento da empresa. A largura da pista de rolamento das estradas principais variou de 4 a 7 metros, sendo que pelo planejamento da empresa, elas deveriam ter 8 metros. Já para as estradas secundárias, a largura da pista de rolamento deveria ter 6 metros, no entanto, foi verificada uma variação de 4 a 7 metros. A análise comparativa dos custos, tendo como cenário primeiramente a situação das estradas levantadas in loco e os padrões de estrada indicados pelo modelo, permitiu notar que adoção do modelo teórico significaria acréscimo de R$ 521,30/km de estrada. Enquanto um segundo cenário comparativo composto pelas características de estradas levantadas em questionário, ou seja, as tidas como modelo para aberturas de novas estradas pela empresa, e os padrões de estrada indicados pelo modelo, indicou que o emprego do modelo teórico possibilitaria uma economia de R$ 2.036,00/km de estrada implantada... / The forest road net influences directly on transport Quality. It serves as access to forests, making possible the traffic of workers and the transporting of raw material. However, one of the main causes of the construction costs increase is the bad conservation and the lack of planning, since their main characteristics are, many times, low volume of traffic and the utilization of weighed and extra-weighed vehicles. Beside the technologic advances and the transport importance for forest companies, nowadays, many companies are worried with the ideal conditions of the forest road net, mainly on the concerning of planning and material quality. The objective of this work was to propose and evaluate a theoretical model of investment to forest road net in function of the volume of wood transported. It was verified that field data were not compatible with the company planning. The width of rolling track of main roads varied from 4 to 7 meters, although to company planning they should be 8 meters. For secondary roads, the width of rolling track should be 6 meters, although, it was observed a variation from 4 to 7 meters. Comparing theoretical model costs with real data, on the concerning of road width, it is verified that, in economic terms, the adoption of theoretical model would mean an investment of R$ 521,30/km more than in relation to that costs obtained from real data and comparing the costs of the theoretical model and the width data, obtained through consult formulary, showed that the usage of theoretical model would make possible an economy of R$ 2.036,00/km of built road. Costs of paved roads building were variable in function of rolling track width and the covering thickness, being this costs calculated as better as possible, as to allow an optimization on resources application.

Ce travail a pour objectif de contribuer à l'étude du magnétisme dans les oxydes isolants de type AB_2O_6 (A= Fe, Co, Ni; B= Ta, Sb). Ces composés cristallisent dans une structure trirutile et présentent une variété très riche de phases magnétiques. Tous les ordres observés peuvent être classés comme antiferromagnétiques mais diffèrent d'un ordre simple de type Néel. En outre, les substitutions comme Fe_xCo_{1-x}Ta_2O_6, Fe_xNi_{1-x}Ta_2O_6 et Co_xNi_{1-x}Ta_2O_6 conduisent à des domaines de coexistence de phases magnétiques et à des points bicritiques dans les diagrammes de phases T(x). Une caractéristique particulièrement intéressante de ces composés est le caractère quasi-bidimensionnel de leur magnétisme, puisque les ions de métaux de transitions A apparaissent dans des réseaux plans séparés par deux plans d'ions non magnétiques B. Une forte anisotropie de champ cristallin est observée sur les sites magnétiques, résultant de la distorsion axiale des octaèdres d'oxygènes qui entourent ces ions A. Nous avons abordé deux aspects complémentaires: théorique et expérimental. Du point de vue théorique, une reformulation du modèle bidimensionnel jusqu'à present utilisée pour décrire la susceptibilité paramagnétique nous a permi d'obtenir des constants d'échange compatibles avec les types d'ordre magnétique planaire observés. Considérant que le caractère tridimensionnel des structures magnétiques révélées par diffraction neutronique indique l'importance du couplage entre plans, quoique faible, à basse température, nous proposons un modèle tridimensionnel coherent avec les ordonnements observés aussi dans le plan ab qu'au long de l'axe c. Du point de vue expérimental, nous faisons des substitutions sur le site non magnétique pour modifier de façon systematique l'espacement entre les plans magnétiques et, en consequence, le couplage entre eux. En particulier, nous avons synthétisé des composés du type ANb_xTa_{2-x}O_6 avec A = Fe, Ni et Co, restant dans le domaine de stabilité de la phase quadratique, puisque la présence de Nb favorise une phase orthorhombique. Une caractérisation structurale et magnétique de ces systèmes est faite par diffraction de rayons X et de neutrons, complétées par des mesures de susceptibilité magnétique, chaleur spécifique et aimantation en fonction du champ appliqué. Nous étudions également des séries avec Sb à la place de Nb où nous avons également effectué des remplacements sur le site magnétique. / This work aims to contribute to the study of magnetism in insulating oxides of the type AB_2O _6 (A = Fe, Co, Ni, Ta = B, Sb). These compounds crystallize in a trirutile structure and present a rich variety of magnetic phases. All the observed orderings can be classified as antiferromagnetic, but they differ from a simple Néel type order. Moreover, substitutions such as Fe_xCo_{1-x}Ta_2O_6, Fe_xNi_{1-x}Ta_2O_6 and Co_xNi_{1-x}Ta_2O_6 produce several regions of phase coexistence and bicritical points in the phase diagram T vs. x. A particularly interesting characteristic of these compounds is the quasi-two-dimensional nature of their magnetism, since the transition-metal ions A appear in layers separated by two planes of the non-magnetic ions B. They also show strong crystal-field anisotropy on the magnetic sites due to axial distortion of the oxygen octahedra surrounding the A ions. Our approach involves two complementary aspects: theoretical and experimental. From the theoretical point of view, a reformulation of the two-dimensional model used until now to describe the paramagnetic susceptibility allows us to obtain exchange parameters compatible with the observed planar magnetic orderings. Considering that the three-dimensional character the magnetic structures revealed by neutron diffraction indicates that the coupling between planes, although weak, plays an important role to low temperatures, we propose a three-dimensional model consistent with the observed orderings both in the ab plane and along the c axis. From the experimental point of view, we make substitutions on the non-magnetic sites, in order to systematically modify the spacing between planes and, consequently, the coupling between them. In particular, we have synthesized compounds of type ANb_xTa_{2-x}O_6 with A = Fe, Ni and Co, remaining in the stability region of tetragonal phase, since the presence of Nb favors an orthorhombic phase. The structural and magnetic characterization of the systems is done via the X-ray and neutron diffraction as well as measurements of magnetic susceptibility, specific heat, and magnetization as a function of the applied field. We also study series with Sb in place of Nb where we additionally include substitutions in the magnetic site.

Resumo: A rede viária florestal influencia diretamente na qualidade do transporte. Ela serve de acesso às florestas, viabilizando o tráfego de mão de obra e o escoamento de matéria-prima. No entanto, uma das principais causas do aumento nos custos de construção é a má conservação e a falta de planejamento, visto que suas principais características são, muitas vezes, o baixo volume de tráfego e a utilização de veículos pesados e extrapesado. Além dos avanços tecnológicos e da importância do transporte para as empresas florestais, hoje, muitas empresas estão se preocupando com as condições ideais de rede viária florestal, principalmente no que se refere aos cuidados com planejamento e qualidade dos materiais utilizados. O objetivo deste trabalho foi propor e avaliar um modelo teórico de investimento para rede viária florestal em função do volume de madeira transportado. Verificou-se que os dados levantados em campo não eram compatíveis com o planejamento da empresa. A largura da pista de rolamento das estradas principais variou de 4 a 7 metros, sendo que pelo planejamento da empresa, elas deveriam ter 8 metros. Já para as estradas secundárias, a largura da pista de rolamento deveria ter 6 metros, no entanto, foi verificada uma variação de 4 a 7 metros. A análise comparativa dos custos, tendo como cenário primeiramente a situação das estradas levantadas in loco e os padrões de estrada indicados pelo modelo, permitiu notar que adoção do modelo teórico significaria acréscimo de R$ 521,30/km de estrada. Enquanto um segundo cenário comparativo composto pelas características de estradas levantadas em questionário, ou seja, as tidas como modelo para aberturas de novas estradas pela empresa, e os padrões de estrada indicados pelo modelo, indicou que o emprego do modelo teórico possibilitaria uma economia de R$ 2.036,00/km de estrada implantada...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The forest road net influences directly on transport Quality. It serves as access to forests, making possible the traffic of workers and the transporting of raw material. However, one of the main causes of the construction costs increase is the bad conservation and the lack of planning, since their main characteristics are, many times, low volume of traffic and the utilization of weighed and extra-weighed vehicles. Beside the technologic advances and the transport importance for forest companies, nowadays, many companies are worried with the ideal conditions of the forest road net, mainly on the concerning of planning and material quality. The objective of this work was to propose and evaluate a theoretical model of investment to forest road net in function of the volume of wood transported. It was verified that field data were not compatible with the company planning. The width of rolling track of main roads varied from 4 to 7 meters, although to company planning they should be 8 meters. For secondary roads, the width of rolling track should be 6 meters, although, it was observed a variation from 4 to 7 meters. Comparing theoretical model costs with real data, on the concerning of road width, it is verified that, in economic terms, the adoption of theoretical model would mean an investment of R$ 521,30/km more than in relation to that costs obtained from real data and comparing the costs of the theoretical model and the width data, obtained through consult formulary, showed that the usage of theoretical model would make possible an economy of R$ 2.036,00/km of built road. Costs of paved roads building were variable in function of rolling track width and the covering thickness, being this costs calculated as better as possible, as to allow an optimization on resources application. / Orientador: Paulo Torres Fenner / Coorientador: Alessandro Antonangelo / Banca: Elias Taylor Durgante Severo / Banca: Claudio Angeli Sansígolo / Banca: Jorge Roberto Malinovski / Banca: Nelson Yoshihiro Nakajima / Doutor