An experimental and analytical investigation was conducted to evaluate the behavior of inflection points as brace points in multi-span purlin roof systems. Seven tests were conducted using "C" and "Z" purlins attached to standing seam and through fastened panels. These tests were subjected to uniform gravity loading by means of a vacuum chamber. The experimental results were compared with analytical predictions based on the 1996 AISI Specifications with and without the inflection point considered a brace point. Finite element modeling of through fastened "C" and "Z" purlin tests were conducted and compared to experimental through fastened results. Conclusions were drawn on the status of the inflection point and on the design of multi-span purlin roof systems with current AISI Specifications. / Master of Science

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-02-28T20:51:46Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) carolina_mata_machado_barbosa_chaves.pdf: 869125 bytes, checksum: f3a73edd9fc230fa83bcba82ad63bf37 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-03-09T20:12:08Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) carolina_mata_machado_barbosa_chaves.pdf: 869125 bytes, checksum: f3a73edd9fc230fa83bcba82ad63bf37 (MD5) / Made available in DSpace on 2018-03-09T20:12:08Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) carolina_mata_machado_barbosa_chaves.pdf: 869125 bytes, checksum: f3a73edd9fc230fa83bcba82ad63bf37 (MD5) Previous issue date: 2017 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG) / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / O enxofre (S) ? um nutriente essencial para crescimento e metabolismo das plantas, e sua defici?ncia pode limitar a produtividade de muitas culturas. A adapta??o de t?cnicas espec?ficas de an?lise espectral para a determina??o do estresse nutricional causado por este nutriente pode permitir a detec??o precoce da sua defici?ncia e suplementa??o de precis?o na aduba??o corretiva das plantas. Esse experimento foi conduzido com o objetivo de determinar se a reflect?ncia foliar obtida atrav?s do mini espectr?metro pode ser utilizada para detectar a defici?ncia de S em mudas de Eucalyptus urophylla. Durante 90 dias as mudas foram cultivadas em solu??o nutritiva de Clark modificada completa (sem omiss?o de S) e com omiss?o de S. Os sintomas visuais de defici?ncia de S foram observados e fotografados semanalmente. A cada 15 dias foram avaliados altura e di?metro das plantas e leituras nas folhas diagn?sticos, com o mini espectr?metro. Ao final de cada avalia??o, amostras de folhas diagn?sticos foram preparadas e submetidas ?s an?lises qu?micas do material vegetal dos teores de nutrientes, posteriormente as mudas foram separadas em ra?zes, caule e folhas para obten??o da massa seca total e dos seus componentes. Ap?s calcular a primeira derivada das reflect?ncias obtidas nas leituras com o mini espectr?metro, obteve-se a posi??o dos pontos de inflex?o. Foi realizado ainda um estudo de regress?o linear m?ltipla entre os teores de nutrientes das folhas diagn?sticos como vari?veis dependentes, e a produ??o de massa seca da parte a?rea e valores obtidos para o IPP como vari?veis independentes. A defici?ncia de S causou altera??es nas propriedades morfol?gicas e fisiol?gicas das plantas de Eucalyptus, o que refletiu nas mudan?as das propriedades espectrais foliares da esp?cie em quest?o. Os sintomas visuais de defici?ncia de S iniciaram-se aos 28 dias ap?s a aplica??o dos tratamentos (DAT), intensificando-se ao longo do experimento. Foi observado clorose nas folhas novas, caule mais delgado e redu??o no crescimento das mudas quando comparados ao tratamento completo. A an?lise nutricional detectou redu??o nas concentra??es de S foliar e defici?ncia do nutriente nas plantas aos 45 DAT. Contudo, somente aos 75 dias a defici?ncia de S alterou a reflect?ncia das mudas com omiss?o de S, deslocando o ponto de inflex?o para comprimentos de ondas mais curtos (? 700 ?m), ou seja, quando o aparelho (mini espectr?metro) conseguiu detectar defici?ncia nutricional de S nas plantas de Eucalyptus. A defici?ncia de S tamb?m reduziu a altura, di?metro e produ??o de massa seca total e dos seus componentes aos 75 DAT. A posi??o do ponto de inflex?o e a massa seca da parte a?rea apresentaram alta correla??o com a concentra??o de S foliar. As an?lises de regress?o linear m?ltipla e de correla??o simples indicaram que os valores de reflect?ncia foliar estimados pelo mini espectr?metro e pela massa seca da parte a?rea estavam estreitamente correlacionados com as concentra??es de S nas folhas das mudas de Eucalyptus (r2=0,99). Os resultados obtidos sugerem que a reflect?ncia espectral demonstra alto potencial como ferramenta diagn?stico para estimar a concentra??o de S foliar em Eucalyptus por meio do mini espectr?metro. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / Sulfur (S) is an essential nutrient for plant growth and metabolism, its deficiency can limit the productivity of many crops. The adaptation of specific remote sensing and spectral analysis techniques for the determination of nutrient stress in plants could allow early detection and precise supplementation for corrective fertilization. This experiment was conducted with the objective of determining if the leaf reflectance obtained through the mini spectrometer can be used to detect S deficiency in Eucalyptus urophylla seedlings. During 90 days the seedlings were grown in complete nutrient solution of Clark (without omission of S) and with omission of S. The visual symptoms of S deficiency were observed and photographed weekly. Every 15 days, plants height and diameter were evaluated, and readings on the diagnostic leaf were taken with the mini spectrometer. At the end of each evaluation the samples of the diagnostic leaves were prepared and submitted to the chemical analyzes of nutrient contents of the plant material, later the seedlings were separated into roots, stem and leaves to obtain the mass of total dry matter and its components. After calculating the first derivative of the reflectances obtained in the readings with the mini-spectrometer, the position of the inflection points was obtained. A multiple linear regression study was carried out between the nutrient contents of the diagnostic leaves as dependent variables and the shoot dry matter yield and values obtained for the position of the inflection points as independent variables. Sulfur deficiency caused changes in the morphological and physiological properties of Eucalyptus plants, which reflected changes in the leaf spectral properties of the species. The visual symptoms of S deficiency began at 28 days after application of the treatments, intensifying throughout the experiment. It was observed chlorosis in the new leaves, slender stem and reduction in the growth of the seedlings when compared to the complete treatment. Nutritional analysis detected a reduction in the foliar S concentrations and nutrient deficiency in plants at 45 days after application of the treatments. However, only at 75 days S deficiency altered the reflectance of the seedlings under S omission, shifting the inflection point to shorter wavelengths (? 700 ?m),that is, when the device (mini spectrometer) was able to detect nutritional deficiency of S in Eucalyptus plants. Sulfur deficiency also reduced the height, diameter and yield of total dry mass and its components at 75 days after application of the treatments. The position of the inflection point and the shoot dry mass presented a high correlation with the concentration of leaf sulfur. Multiple linear regression and simple correlation analyzes indicated that leaf reflectance values estimated by the mini spectrometer and through MSPA were closely correlated with the concentrations of S in the leaves of the Eucalyptus seedlings (r2 = 0.99).The results obtained suggest that the spectral reflectance demonstrates high potential as a diagnostic tool to estimate the leaf sulfur concentration in Eucalyptus using the mini-spectrometer.

Submitted by GIULIA LEMBO CATERINA null (giucaterina@hotmail.com) on 2017-04-03T21:59:24Z No. of bitstreams: 1 Giulia_Caterina_tese.pdf: 2061741 bytes, checksum: ba5089a3900a08b417c76904274f934d (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-11T20:50:43Z (GMT) No. of bitstreams: 1 caterina_gl_dr_bot.pdf: 2061741 bytes, checksum: ba5089a3900a08b417c76904274f934d (MD5) / Made available in DSpace on 2017-04-11T20:50:43Z (GMT). No. of bitstreams: 1 caterina_gl_dr_bot.pdf: 2061741 bytes, checksum: ba5089a3900a08b417c76904274f934d (MD5) Previous issue date: 2017-02-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Modelos de crescimento podem servir como ferramenta de planejamento de plantios florestais para o serviço público, produtores e investidores. O presente trabalho utilizou o modelo de crescimento Gompertz para analisar e comparar curvas médias de crescimento em volume de madeira com casca e sem casca por árvore de dois clones distintos de Eucalyptus grandis x Eucalyptus urophylla em diferentes densidades de plantio: 1,5m x 1,5m, 3,0m x 0,75m, 3,0m x 1,0m, e 3,0m x 1,9m. Os dados foram coletados a partir de parcelas permanentes localizadas em plantios da empresa Duratex Florestal LTDA no município de Estrela do Sul - MG em quatro idades: 24, 36, 48 e 60 meses. As análises seguiram duas abordagens. A primeira abordagem foi pela curva de crescimento utilizando o modelo Gompertz, do qual foram ajustadas as curvas médias de crescimento. Os parâmetros estimados de interesse foram a velocidade máxima de crescimento no ponto de inflexão e a abscissa da inflexão. A segunda abordagem foi pela modelagem do máximo volume com e sem casca amostrais através de modelos lineares generalizados. O efeito de clone e espaçamento foi avaliado e as médias dos maiores volumes amostrais foram, também, comparadas entre tratamentos. Os dados observados de volume com e sem casca por árvore permitiram bons ajustes do modelo de Gompertz, com o objetivo de descrever o crescimento destas variáveis ao longo do tempo. Foi possível identificar as fases juvenil, que vai até o ponto de inflexão da curva e de maturidade, que vai do ponto de inflexão até o ponto de máxima tangência nas curvas projetadas para quase todos os tratamentos. Porém, o período de dados coletados não foi o suficiente para se modelar a curva de crescimento por árvore até a senescência da curva, mesmo para os espaçamentos mais adensados. As maiores médias de velocidade máxima de crescimento individual foram encontradas no espaçamento mais amplo, 3,0m x 1,9m, para ambos os clones, assim como as maiores médias dos volumes individuais máximos com e sem casca. O clone c1 apresentou maiores médias dos volumes individuais máximos com e sem casca por árvore observados que o clone c2. A idade do plantio se mostrou essencial na discussão sobre a produtividade de diferentes arranjos de plantio. Portanto, este estudo confirma a importância do uso de curvas de crescimentos em estudos na área florestal. / Growth models can serve as a tool for forest management plans for public service, producers and investors. The present work used the Gompertz growth model to analyze and compare individual volume growth curves of three distinct clones of Eucalyptus grandis x Eucalyptus urophylla at different planting densities. Four different spacings densities were evaluated, 3.0m x 0.75m, 1.5m x 1.5m, 3.0m x 1.9m and 3.0m x 1.0m, for each clone at two different sites, São Paulo and Minas Gerais General. The data were collected from permanent plots at four ages: 24, 36, 48 and 60 months. The analyzes followed two approaches. The first approach was to adjust the growth curve using the Gompertz model to the volume data. The estimated parameters of interest, analyzed later, were the maximum velocity of growth at the inflection point and the abscissa of the inflection point. For each estimated parameter, generalized linear models were adjusted to detect the effect of location, clone and spacing. Thus, the adjustment was made for each portion of the treatments and the means of the estimated parameters were compared. The second approach was the modeling of the largest volume observed through generalized linear models. The effect of site, clone and spacing were evaluated and the means of the largest sample volumes were compared between treatments. The observed data of volume with and without bark per tree allowed good adjustments of the Gompertz model, in order to describe the growth of these variables over time. It was possible to identify the juvenile phase, which goes from first years to the point of inflection, and the maturity phase, which goes from the point of inflection to the point of maximum tangency, for almost all treatments. However, the period of data collection was not sufficient to get the curves to the senescence phase, even for the denser spaces. The spacing density 3.0m x 1.9m resulted on the higher averages of maximum individual growth velocity and on the higher mean values of the observed volumes with and without bark. Clone c1 presented higher mean values of the observed volumes with and without bark per tree than clone c2. The stand age was shown to be essential in the discussion of a productivity of different densities arrangements. Therefore, this study confirms the importance of the use of growth curves in studies in forestry.

No description available.

Better understanding of the role of vegetation in the transport of fluid and pollutants requires improved knowledge of the detailed flow structure within the vegetation. Instead of spatial averaging, this study uses discrete measurements at multiple locations within the canopy to develop velocity and turbulence intensity profiles and observe the changes in the flow characteristics as water travels through a vegetation array simulated by rigid dowels. Velocity data were collected with a one dimensional laser Doppler velocimeter (LDV) under single layer emergent and submerged flow conditions, and through two layers of vegetation. The effects of dowel arrangement, density, and roughness are also examined under the single layer experiments. The results show that the velocity within the vegetation array is constant with depth and the velocity profile is logarithmic above it. The region immediately behind a dowel, where the vorticity and turbulence intensity are highest, is characterized by a velocity spike near the bed and an inflection point near the top of the dowel arrays. With two dowel layers, the velocity profile in the region behind a tall dowel exhibits multiple inflection points and the highest turbulence intensities are found there. / Master of Science

Boundary layer rolls are a rather frequent phenomena, where regions of alternating up- and downdraft motion causes clouds to form in elongated, parallel rows oriented with the mean wind direction. The clouds can be seen during certain atmospheric conditions and are often called ”cloud streets” because of their characteristic appearance. By performing a linear instability analysis, the underlying mechanisms causing the onset of boundary layer rolls has been analysed in this study. There are two governing mech- anisms that cause the boundary layer rolls to form, the thermal instability and the dynamic instability. The thermal instability is caused by convection in an unstable airmass, while the dynamic instability usually is associated with neutral or stable conditions. The dynamic instability arise due to an inflection point in the wind profile, around which eddies develop. In a previous study by Svensson et al. (2017), rolls were observed over the Swedish east-coast, stretching out over sea during four days; 2 of May 1997, 3 of May 1997, 17 of May 2011 and 25 of May 2011. The aim of this study is to simulate the rolls on these four dates, analyse the underlying mechanisms and establish what type of instability that primarily causes the rolls to form. The linear stability analysis performed in this study indicate that the dynamic instability is the main mechanism giving rise to the rolls on all four studied dates. The rolls are found to arise over the Swedish mainland and are advected out over the sea. Both the orientation of the rolls and the modeled wind direction are in accordance with the observations. A qualitative agreement is found for the wavelength, the amplitude and the altitude of the rolls, when comparing the results of this study with the observations.

This thesis is mainly concerned with some important properties of complex fluids, and how these properties are influenced by structures in the nano/mesoscopic scale. Short-range assembly of the constituent molecules results in an amazing variety of phase behavior in these systems. Liquid-liquid phase transitions, or transitions from a homogeneous(mixed) phase to an immiscible phase (two-phase coexistence), are the outcome of a competition between entropy and short-ranged attractive forces, and form an important part of this thesis. A rich phase behavior is uncovered by a detailed study of liquid-liquid phase transitions in a mixture of ethanol(E) and water(W), induced by the addition of ammonium sulfate(AS) ions (E and W are otherwise completely soluble in each other). This is the main motivation for choosing this system. Furthermore, experimental evidence of the presence of supramolecular association in alcohol-water mixtures [J.-H. Guo et al., Phys. Rev Lett, 91, 15401(2003)] enhances our interest to study the phase behavior in more detail. The presence of a critical point, at which there is a second order phase transition, is quite common in complex fluids. An issue which has been the subject of extensive scientific research in recent years is the influence of nano/mesoscopic structure on the critical behavior of these fluids corresponds to the Ising universality class. However, the approach to the asymptotic regime is governed by a competition between the correlation length of critical concentration fluctuations and the additional length scale arising due to structuring., which results in a crossover from the universal Ising behavior to the mean-field behavior, sometimes within the critical domain. This phenomenon of crossover criticality is presently explored in the E + W + AS system. A significant portion of the thesis presents explorations on the critical behavior in the vicinity of special critical points (SCP), which are formed by the coalescence of two or more critical points. Recentrant liquid-liquid phase transitions observed in the E + W + AS system, furnishes an unique opportunity for the realization of three SCPs – the double critical point(DCP) and the critical double point(CDP) formed by the merger of two critical points , and a critical inflection point(CIP), formed by the merger of three critical points. A CIP had not been experimentally realized prior to the studies presented in this thesis. Apart from the above studies investigations are also carried out on the conformational changes of a technologically important conducting polymer, polyethylene dioxythiophene doped with polystyrene suflonate (PEDOT-PSS), in various solvents. The electrical and optical properties of the polymer films get enhanced when solution processed with specific solvents. The experiments presented in this thesis are directed at unraveling the role of conformational modifications in the electrical and optical properties of these systems. The experimental techniques that were employed in the present studies are: Laser light scattering, small-angle X-ray scattering(SAXS) measurements and visual observations. The eoexistence surface of the system E + W + AS was determined by visual observations. Laser light scattering measurements were conducted to study the critical behavior of osmotic susceptibility (xr) of E + W + As, whereas SAXS studies were conducted to ascertain the existence, and quantify the spatial extent of the additional length scale in the two systems investigated. The main objectives of this research were: (i) to study the phase behavior of the ternary mixture E + W + AS at atmospheric pressure; (ii) to check the existence of crossover from 3-D Ising to mean-field critical behavior while moving away from Tc in this system; (iii) to determine the nature (monotonic or nonmonotonic) of crossover; (iv) to provide some insight into the origin of this crossover behavior in terms of an additional length scale characteristic of the system; (v) to understand the evolution of the critical behavior in the proximity of CDP, and DCP; (vi) to experimentally realize the CIP; and (vii) to investigate the presence of solvent-induced conformational changes in conducting polymer.

Bar code stores information in the form of series of bars and gaps with various widths, and therefore can be considered as an example of bilevel (square) signal. Magnetic bar codes are created by applying slightly ferromagnetic material to a substrate. Sensing is done by reading oscillator, whose frequency is modulated by presence of the mentioned ferromagnetic material. Signal from the oscillator is then subjected to frequency demodulation. Due to temperature drift of the reading oscillator, the demodulated signal is accompanied by DC drift. Method for removal of the drift is introduced. Also, drift-insensitive detection of presence of a bar code is described. Reading bar codes is complicated by convolutional distortion, which is result of spatially dispersed sensitivity of the sensor. Effect of the convolutional distortion is analogous to low-pass filtering, causing edges to be smoothed and overlapped, and making their detection difficult. Characteristics of convolutional distortion can be summarized into point-spread function (PSF). In case of magnetic bar codes, the shape of the PSF can be known in advance, but not its width of DC transfer. Methods for estimation of these parameters are discussed. The signal needs to be reconstructed (into original bilevel form) before decoding can take place. Variational methods provide effective way. Their core idea is to reformulate reconstruction as an optimization problem of functional minimization. The functional can be extended by other functionals (regularizations) in order to considerably improve results of reconstruction. Principle of variational methods will be shown, including examples of use of various regularizations. All algorithm and methods (including frequency demodulation of signal from reading oscillator) are digital. They are implemented as a program for a microcontroller from the PIC32 family, which offers high computing power, so that even blind deconvolution (when the real PSF also needs to be found) can be finished in a few seconds. The microcontroller is part of magnetic bar code reader, whose hardware allows the read information to be transferred to personal computer via the PS/2 interface or USB (by emulating key presses on virtual keyboard), or shown on display.

摘要 組織乃社會網絡的一員，其必須正視後現代主義者對當今後現代社會的觀察，以及必須面臨的嚴苛挑戰! 本論文旨在探討後現代主義思潮對當代組織的影響與啟示為何?部分當代管理情境(或稱後現代情境)， 例如，追求一切可能性、對簡單之渴望、感性的思維、 不確定性、 快速變遷、不連續性、模糊、 無界限、解構、 去中間化、 片斷化、 以族群取代社會階級、 多元化、尊重差異、超現實、以及反宰制性規則等等，對當代組織(或稱後現代組織)現在或未來在策略擬定時的影響與啟示為何? 面對後現代情境及其挑戰 ， 後現代組織現在或未來對策略之再思考為何? 後現代組織未來可能適用之新的組織模式為何? 以及後現代組織對策略之再思考的實務作為為何? 本研究主要以文獻探討與次級資料檢索之檔案研究法為主，資料檢索的對象(含個案資料之來源)是以探討較高層次的概念性策略新思維為主。至於屬於研究輔助性質之個案部分，則以屬於營利性質之全球知名多國籍企業、由製造導向轉型為服務導向者、或者可印證本研究所探討之策略新思維者為主。 經由本探索研究後發現，面對後現代主義思維的衝擊，以及後現代管理情境的挑戰，組織應該重新檢視其前提假設、回歸策略本質、勾勒遠大的構想、開創新的價值曲線以避開面對面競爭、重新尋找組織在數位世界的價值定位與經營模式、專注核心、建立社群、培養廣義「顧客」----利害關係人之新的忠誠度、善用所有利害關係人的關係與優勢、 注重組織內外部的整合以及策略要素之間的整合與一致性、擺脫語言牢籠(規則)的束縛而賦予員工彈性、持續尋找任何強調彈性結構、網絡關係、溝通效率、以及民主化機制的組織模式或概念。 最後，對於全球的多國籍企業，本研究建議其必須在全球的產業分工體系之下，勾勒遠大的構想、開創新的價值曲線、發展世界級的核心能力、建立或主導某些內外部社群或電子企業社群、採行time pacing策略以穩健成長、強化跨產業或跨國之組織與策略整合的作為、時時檢視與修改任何宰制性的政策或規則、以及繼續尋找與試行任何可能且可行的組織模式或概念。 / Abstract Organizations that are parts of social network must take into account those issues discovered and criticized by Postmodernist and those severe challenges facing organizations. This dissertation tries to explore those impact and implications aroused by postmodernist for contemporary organizations, those contemporary scenario (postmodern scenario) facing organizations, such as in search of possibilities, in need of simplicity, sensuous thinking, indeterminacy, a rapidly changing environment, discontinuity, ambiguity, boundarylessness, borderless, deconstruction, disintermediation, fragmentation, social class replaced by tribes, diversity, apprizing difference or otherness, hyperreality, and against governing rules, that will affect the strategic planning of organizations at present or in the coming future. In addition, this dissertation also tries to explore that currently or in the coming future how organizations rethink their strategies while facing postmodern scenario and its rigorous challenges, what forms, models or concepts of organization design that organizations can apply, and those managerial practices that organizations have ever executed. The research methodology adopted by this dissertation is primarily literature review and secondary data exploration. The target data including cases are focused on those conceptual strategic thinking. Those cases that are mainly complement to this dissertation are those distinguished multinational corporations (MNC) that have ever been transformed from manufacturing-oriented to service-oriented, or are able to prove partial strategic thinking reviewed in the dissertation. In the face of those thinking impact stirred by postmodernist and challenges resulted from postmodern managerial scenario, this dissertation concludes that organizations should review and rethink their assumption for the world, revisit the essence of strategy, picture and propose the big ideas, create or explore new value curves to avoid cruel face-to-face competition, explore new value positions and business models in the digital world, focus and develop core businesses and competence, build and manage communities, cultivate new types of royalty for those stakeholders partnering with organizations, utilize the relationships with and advantages from stakeholders, emphasize and advocate internal and external organizational integration and consistence and alignment for strategies, free from the cage of language and empower employees, keep exploring those organizational models or concepts that advocate or propose flexibility, networks of people, efficiency of communication, and spirit of democracy. In conclusion, this dissertation suggests that under global industrial value chains, multinational corporations should picture and propose the big ideas, create and explore new value curves, develop best-in-world core competence, form or dominate some internal or external communities or e-business communities, adopt strategy of time pacing for sound and moderate growth, reinforce cross-industry or cross-nation integration for organizations and strategies, keep reviewing and modifying any governing policy or rules, and keep searching and experimenting any latest possible and feasible models or concepts of organization.