O Litoral Norte de São Paulo é uma região pouco impactada e com elevada sensibilidade ecológica e que reúne perspectivas de grande crescimento econômico com novas instalações de empresas ligadas à exploração do PRÉ-SAL. O presente estudo tem como objetivo analisar a toxicidade dos sedimentos dos Municípios de Ubatuba e Caraguatatuba com os procedimentos da Avaliação e Identificação da Toxicidade (AIT), somente a fase I, proposto pela USEPA (1991; 2007). O ensaio de toxicidade crônico de desenvolvimento embriolarval do ouriço do mar Lytechinus variegatus. Foi extraída a água intersticial dos sedimentos, coletados em quatro enseadas, pelo método de sucção descrito por Winger & Lasier (1991), sendo dois pontos de coleta na Enseada de Ubatuba - Perequê-Açu e Itaguá, um na Enseada do Flamengo, um na Enseada do Mar Virado e uma na Enseada de Caraguatatuba. A AIT evidenciou como agente causador da toxicidade, de modo geral, os compostos pH dependentes e dos metais. As amostras do Perequê-Açu e de Caraguatatuba apresentaram toxicidade em todas as amostras analisadas, as demais amostras não presentaram nenhuma relação entre a toxicidade e a sazonalidade. / São Paulo north coast is a poor impacted region and with high ecological sensitivity which gathers perspectives of great economic growth with new facilities related to the operation of the Pre-Salt companies. The aim of the present study is to analyze the toxicity of sediments from the municipalities of Ubatuba and Caraguatatuba with the procedures of the Toxicity Identification Evaluation (TIE), only the phase I, proposed by USEPA (1991, 2007). The test of chronic toxicity of embriolarval development of sea urchin Lytechinus variegates. Pore water was extracted from the sediments collected in four bays, by the suction method described by Winger & Lasier (1991), being two collection points in Ubatuba Bay - Perequê-Açu and Itaguá, one in Flamengo Bay, one the Mar Virado Bay and one in Caraguatatuba Bay. The TIE evidenced as a causative agent of toxicity, in general, the compounds of pH dependent and of metals. The samples of Perequê-Açu and Caraguatatuba showed toxicity in all samples, the other samples showed no relationship between toxicity and seasonality.

The strut-and-tie method (STM) is a simple and conservative method for designing concrete structures, especially deep beams. This method expresses complicated stress patterns as a simple truss or kinematic model made up of compression elements (struts), tension elements (ties), and the joints between elements (nodes). STM is based on lowerbound plasticity theorem, so using it properly will lead to a conservative design. Although the concepts of STM have been around in concrete design since the late 19th century, STM was first introduced in AASHTO LRFD in 1994 and ACI 318-02 in 2002. ACI 318 defines two different types of struts (prismatic and bottle-shaped) based on whether compression stress can spread transversely along the length of the strut. Recent work has brought into question whether these two types of struts do exist and whether current design provisions conservatively estimate failure loads for all members. The performance of struts and nodes were investigated experimentally by testing six fullscale concrete deep beams. The specimens had two different shapes (rectangular and trusslike), two different shear span-to-depth ratio (1 and 1.6), and three different types of development (externally unbonded bars, internally bonded hooked bars, and internally bonded bars with welded external plates). All the specimens were supported vertically and vii tested under a three-point load setup. Based on the results, the truss-like specimen failed at higher loads than rectangular specimens with the same shear span-to-depth ratio. According to these results and recent debate in the literature, bottle-shaped struts are not weaker than prismatic struts because of their shape. They are weaker due to shear failure where struts cross a diagonal tension field. Therefore, the structures should be separately checked for shear strength when they are designed with STM. In this dissertation, the development of the design equation for shear strength of discontinuity regions was introduced, and the procedure is under consideration for adoption in ACI 318-19. This research was expanded numerically by studying the effect of development type and length, strut type, and strut angle on the behavior of concrete deep beams. The crack patterns and load-displacement curves, which were obtained from experimental tests, were used to validate numerical models. The strength of concrete deep beams was assessed by modeling thirty-five specimens in a nonlinear finite element software. According to the results, development length and development types influenced the presence of tensile stress in the support nodes. Additionally, the effect of the tensile stresses from reinforcement development and diagonal tension were not additive in rectangular specimens.

The interstate highway system is vitally dependent upon current and future bridges. These bridges must be designed economically to continue the serviceability with limited maintenance. For precast bridge construction a portion of the design must consider the bridge connections. Some current connections have proved insufficient in serviceability as there is uncontrolled cracking. In other connections there are uncertainties in the calculations (or lack of calculations) which require design guidelines. This thesis presents design recommendations for precast decking u-bar reinforcement in tension which results from negative moment over a pier. Testing results from the University of Tennessee were analyzed to determine the design recommendations. The calculated capacity of the specimens was determined first by strut and tie modeling by AASHTO and ACI, but was shown to be insufficient. Proposed changes to the current calculation of the strut width as specified in AASHTO and ACI STM methods were discussed in order to match the test results. However, strut and tie modeling demonstrated that the design for the lacer bar was inadequate. Since the strut and tie modeling method resulted in an inaccurate lacer bar size, another method was developed. A triangular shape develops from the flow of forces in the connection joint zone; as a result, a free body diagram (FBD) was developed from the concrete triangular shape. This diagram showed how the forces flow in the in-situ joint as well as how they are resisted. A formula was developed from the FBD to determine the capacity of the joint which accurately reflected the capacities from tests. A FBD was also made of the lacer bar utilizing the forces and geometry calculated from the capacity calculations. A computer analysis program was used to determine the forces in the lacer bar. The lacer bar could then be designed since the required forces to resist (moment and shear) were known. A comparison of the strut and tie model to the triangular method led to the conclusion that both can determine the longitudinal reinforcement spacing, joint overlap length, and concrete strength, but only the triangular method can determine a more sufficient lacer bar size.

Minimum miscibility pressure (MMP) is a key parameter in the design of gas flooding. There are experimental and computational methods to determine MMP. Computational methods are fast and convenient alternatives to otherwise slow and expensive experimental procedures. This research focuses on the computational aspects of MMP estimation. It investigates the shortcomings of the current computational models and offers ways to improve the robustness of MMP estimation. First, we develop a new mixing cell method of estimating MMP that, unlike previous "mixing cell" methods, uses a variable number of cells and is independent of gas-oil ratio, volume of the cells, excess oil volumes, and the amount of gas injected. The new method relies entirely on robust P-T flash calculations using any cubic equation-of-state (EOS). We show that mixing cell MMPs are comparable with those of other analytical and experimental methods, and that our mixing cell method finds all the key tie lines predicted by MOC; however, the method proved to be more robust and reliable than current analytical methods. Second, we identify a number of problems with analytical methods of MMP estimation, and demonstrate them using real oil characterization examples. We show that the current MOC results, which assume that shocks exist from one key tie line to the next may not be reliable and may lead to large errors in MMP estimation. In such cases, the key tie lines determined using the MOC method do not control miscibility, likely as a result of the onset of L₁-L₂-V behavior. We explain the problem with a simplified pseudo-ternary model and offer a procedure for determining when an error exists and for improving the results. Finally, we present a simple mathematical model for predicting the MMP of contaminated gas. Injection-gas compositions often vary during the life of a gasflood because of reinjection and mixing of fluids in situ. Determining the MMP by slim-tube or other methods for each possible variation in the gas-mixture composition is impractical. Our method gives an easy and accurate way to determine impure CO₂ MMPs for variable field solvent compositions on the basis of just a few MMPs. Alternatively, the approach could be used to estimate the enrichment level required to lower the MMP to a desired pressure. / text

The pressure distribution at the ballast-tie interface of railroad track plays a key role in overall track support. Failure of the ballast or tie can result from excessive loads that were not designed for, requiring increased maintenance and reducing railroad operating efficiency. Understanding the forces acting on the ballast and tie are required to design higher performance and longer lasting track. To further this understanding, the use of Matrix Based Tactile Surface Sensors (MBTSS) is employed to measure the actual pressure distribution at the ballast-tie interface, characterized by individual ballast particle contact points and non-uniform pressures. The research explores this application of MBTSS including the development of sensor protection and calibration procedures. Results from laboratory ballast box testing conducted at the Transportation Technology Center, Inc. (TTCI) are presented. Conservative estimates of peak pressure under a typical wheel load on new ballast averaged 1450 psi and on fouled ballast averaged 680 psi. Contact areas varied across the range of ballast gradations and are shown to increase under increased applied load. A parameter to describe the "roughness" of the ballast-tie pressure distribution is offered. Results from in-track testing performed at TTCI, including pressure distributions along ten test ties, are also presented.

人脈理論相關的文獻,尤以 Granovetter(1973)提出非常優雅的「弱連結 (weak tie)」一詞最為經典,他的論文發現經由弱連結介紹新工作的成功率高於 強連結,同時提出弱連結相較於強連結(strong tie)更多元,因此弱連結對宏觀世 界的效益必大於強連結。而後 Rogers(2006)也在創新的擴散中提出弱連結應 該屬於異質性連結,強連結則屬於同質性的連結,異質性不容易連結卻對擴散的 影響更大。因此本研究的動機將以弱勢的創業家為研究對象,探討弱連結擴散的 動機與擴散方法,並回答研究問題弱連結的擴散效益為何? 本研究發現弱連結的脆弱並不全然是異質性不易溝通之故,因為弱連結與強連結最大的不同是強連結靠關係遠近產生連結,弱連結則是自願性的連結居多,因此創業家的創夢才是真正點燃連結的起源,此外弱連結的橋樑特質是喜好轉介稀有性消息,產生消息經濟的效益而達到更廣泛的連結,因此研究者認為弱連結應用於創新擴散將有三點效益,第一點是弱連結因為自發性動機與可被信任的第三方而提高傳遞意願,第二點是弱連結以泛泛之交居多,他們喜好轉介稀有性消息,因此提高傳送廣度,最後發現所謂的六度分隔除了代表差異性人脈將造成平 均為六的結果外,也代表著六個人脈圈,本研究因此發現第一度的人脈差異將影 響網際網路時代的小世界接受率。 而對於創業家以弱連結來進行創新擴散,研究者認為實務上建立異質性創業 團隊將有助於進入不同特質的弱連結樞紐區,此外創業家勇於發表創夢的想法, 其心態越開放也有助於凝聚弱連結,因此創業家可以藉由社群網站或部落格等媒 體建立自行發聲的管道,將有助於幫助創業家位於樞紐中心,強化擴散的能力。 研究者在回顧文獻後也發現,弱連結在開放式網絡下的橋樑特質與效益被後來學 者忽略,同時隨著網際網路興起帶來多元的媒體與開放式人際關係,研究者認為 將更有助於觀察弱連結對創新擴散的幫助,本研究觀察 Apps 產業裡 Bonnie’s Brunch 個案後,經由八位訪談者與半年的網路社群媒體追蹤的結果,發現弱連 結的橋樑功能是資訊的聚集處,也是連結的捷徑,因此擁有對的連結的確是很重要的事,但是弱連結卻未必時常擔任善意的陌生人,因此弱連結的連結困難在於弱連結的自願性動機,因此研究者在理論貢獻部分提出弱連結的力量來源為自願性的動機,這股隱性的力量唯有受到單純動機的點燃才能爆發出來,因此創業家成功的方程式還有一項無法被操控的弱連結影響力,唯有創業家經過長期的耕耘,持續提供資訊交換,才能與弱聯結維繫關係。 / Among the personal network theory related literatures, the elegant term “weak tie” proposed by Granovetter(1973) is the most classic theory. His thesis paper finding shows that the success rate of introducing new jobs through a weak tie is higher than that of a strong tie. Hence, he believes that as the macroscopic view of the world’s weak tie is more diverse than the strong tie, the benefits produced after creating the tie are definitely greater than the strong tie. Rogers (2006) later proposed in diffusion of innovation that the weak tie is the tie of heterogeneity, while the strong tie is the tie of homogeneity. Heterogeneity does not easily produce a tie, but it has a greater impact on diffusion. Therefore, the weak tie diffusion motivation and diffusion method were explored in this study, and the research problem, i.e., the diffusion benefits of the weak tie, was answered. It was found in this study that the vulnerability of the weak tie is not entirely due to the communication difficulty of heterogeneity, because the greatest difference between the weak tie and strong tie lies in the fact that strong ties produce ties depending on the distance of a relationship, while weak ties are generally voluntary ties. Hence, entre- preneurs’ building of dreams is the actual source that triggers ties. In addition, the weak tie bridge is characterized by a preference to prefer rare news, Newsonomics, and achieve more extensive links. Thus, the researcher believes that there are three benefits when the weak tie is applied in diffusion of innovation. First, the weak tie enhances the willingness to convey messages due to its own voluntary motivation and trustworthy third party. Second, weak ties are generally formed by acquaintances. They prefer to refer rare news, thus the broader conveyance. Lastly, it was found that the so-called six degrees not only represents differential personal networks that result in the outcome of six on average, but also represents six network circles. It was therefore found in this study that the first-degree personal network will affect the small world acceptance rate in the Internet age. As for entrepreneurs, they engaged in diffusion of innovation through weak ties. The researcher believes that, in practice, the establishment of the entrepreneurial team of homogeneity is conducive to entry into weak tie hubs of different characteristics. In addition, entrepreneurs had the courage to express their ideas about building dreams, and their open-mindedness also contributed to the gathering of weak ties. Hence, it is suggested that entrepreneurs establish channels to voice themselves through communi- ty networks, BLOG, and other medias, which will help them stay in the hub and strengthen their ability to diffuse. Through literature review, the researcher found that the bridging characteristics and benefits of the weak tie in the open-type network had been neglected by subsequent researchers. At the same time, the rise of the Internet has brought about a diversity of media and open-type interpersonal relationships, which is believed to be more helpful for weak ties to contribute to diffusion of innovation. Through observations made on the entrepreneurs of Bonnie’s Brunch in the App industry, the results of interviews with 8 individuals, and long-term tracking of Internet community media, it was found that the bridge of the weak tie is a gathering place of information and it is also a shortcut of ties. Therefore, having the right links is indeed important. However, the weak tie is not always willing to serve as the stranger that displays goodwill. The difficulty in linking weak ties therefore lies in the voluntary motivation of the weak tie. In the researcher’s theoretical contributions, it was mentioned that the source of the weak tie force is the voluntary motivation, and this implicit force can only explode after igniting pure mo- tive. Therefore, the successful equation still possesses the influence of the weak tie that cannot be manipulated. Only through long-term cultivation of entrepreneurs and con- tinuous provision of information exchanges to maintain the relationships with weak ties.

Made available in DSpace on 2014-12-17T14:48:13Z (GMT). No. of bitstreams: 1 JulioCCD_DISSERT.pdf: 5293520 bytes, checksum: 35065f2bef6951ad4ce1b2b752aa3b02 (MD5) Previous issue date: 2012-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The main objective of this thesis was the study of bracing panels of structural masonry, by applying the Finite Element Method and Strut and Tie Method. It was analyzed the following aspects: the effect of orthotropy on the behavior of the panels; distribution of horizontal forces between panels for buildings; comparison between Equivalent Frame and Finite Elements models; panels design with the Strut and Tie Method. The results showed that one should not disregard the orthotropy, otherwise this can lead to models stiffer than the real. Regarding the distribution of horizontal forces, showed that the disregard of lintels and shear deformation leads to significant differences in the simplified model. The results showed also that the models in Finite Element and Equivalent Frame exhibit similar behavior in respect to stiffness of panels and stress distribution over the sessions requested. It was discussing criteria for designing Strut and Tie Method models in one floor panels. Then, the theoretical strength these panels was compared with the rupture strength of panels tested in the literature. The theoretical maximum strength were always less than the rupture strength of the panels obtained in tests, due to the fact that the proposed model cannot represent the behavior of the masonry after the start of the panel cracking due to plasticization of the reinforcement / O objetivo principal desta disserta??o foi o estudo de pain?is de contraventamento de alvenaria estrutural, atrav?s da aplica??o do M?todo dos Elementos Finitos e do M?todo de Bielas e Tirantes. Foram analisados os seguintes aspectos: o efeito da ortotropia no comportamento de pain?is; distribui??o de for?as horizontais entre pain?is de edif?cios; compara??o entre os modelos de P?rtico Equivalente e Elementos Finitos; c?lculo de pain?is com o M?todo de Bielas e Tirantes. Os resultados permitiram concluir que n?o se deve desconsiderar a ortotropia, sob pena de conduzir a modelos mais r?gidos que o real. Em rela??o ? distribui??o de for?as horizontais, evidenciou-se que a desconsidera??o dos lint?is e da deforma??o por cisalhamento acarretam diferen?as significativas relativamente ao modelo de barras isoladas. Os resultados permitiram concluir, ainda que os modelos em Elementos Finitos e de P?rtico Equivalente apresentam comportamento semelhante no que se refere ? rigidez de pain?is e distribui??o de tens?es nas sess?es mais solicitadas. Foram discutidos crit?rios para a concep??o de modelos de bielas e tirantes em pain?is isolados. Em seguida, a for?a horizontal te?rica destes pain?is foi comparada com a carga de ruptura de pain?is ensaiados dispon?veis na literatura. As for?as m?ximas te?ricas foram sempre inferiores ? for?a de ruptura dos pain?is, obtidas em ensaios, devido ao fato de que o modelo proposto n?o ? capaz de representar o comportamento da alvenaria ap?s o inicio da fissura??o do painel devido ? plastifica??o das armaduras

The present research is conducted to investigate the structural behaviour of continuously supported deep beams made with SCC. A series of tests on eight reinforced two-span continuous deep beams made with SCC was performed. The main parameters investigated were the shear span-to-depth ratio, the amount and configuration of web reinforcement and the main longitudinal reinforcement ratio. All beams failed due to a major diagonal crack formed between the applied mid-span load and the intermediate support separating the beam into two blocks: the first one rotated around the end support leaving the rest of the beam fixed on the other two supports. The amount and configuration of web reinforcement had a major effect in controlling the shear capacity of SCC continuous deep beams. The shear provisions of the ACI 318M-11 reasonably predicted the load capacity of SCC continuous deep beams. The strut-and-tie model recommended by different design codes showed conservative results for all SCC continuous deep beams. The ACI Building Code (ACI 318M-11) predictions were more accurate than those of the EC2 and Canadian Code (CSA23.3-04). The proposed effectiveness factor equations for the strut-and-tie model showed accurate predictions compared to the experimental results. The different equations of the effectiveness factor used in upper-bound analysis can reasonably be applied to the prediction of the load capacity of continuously supported SCC deep beams although they were proposed for normal concrete (NC). The proposed three dimensional FE model accurately predicted the failure modes, the load capacity and the load-deflection response of the beams tested.

Submitted by Josmary Karoline Demko Alves (josmarykaroline@yahoo.com.br) on 2016-10-29T19:29:03Z No. of bitstreams: 1 Dissertação Josmary vfinal.pdf: 958731 bytes, checksum: 99f22613883eb6a31dcd046c8ee98a08 (MD5) / Approved for entry into archive by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br) on 2017-01-25T12:38:46Z (GMT) No. of bitstreams: 1 Dissertação Josmary vfinal.pdf: 958731 bytes, checksum: 99f22613883eb6a31dcd046c8ee98a08 (MD5) / Made available in DSpace on 2017-02-02T18:20:37Z (GMT). No. of bitstreams: 1 Dissertação Josmary vfinal.pdf: 958731 bytes, checksum: 99f22613883eb6a31dcd046c8ee98a08 (MD5) Previous issue date: 2016-08-29 / Estruturas sociais influenciam a efetividade dos grupos. O propósito deste estudo é explorar os efeitos contingenciais dessa relação por meio da investigação da densidade em diferentes redes na performance das equipes. Hipotetizou-se, primeiramente, o efeito oposto para densidade instrumental e afetiva em performance das equipes; posteriormente, argumenta-se que interdependência das tarefas e a orientação de distância de poder agem como moderadores. Para testar as hipóteses, foram utilizadas informações de questionários coletados de 27 Unidades de Pronto Atendimento (UPA) e 106 grupos. O resultado encontrado suporta o efeito positivo de densidade instrumental e o impacto negativo da densidade afetiva. Além disso, provou-se que a interdependência de tarefas atenua ambas as relações diretas. Ao final, são discutidas as implicações destes resultados para pesquisa em densidade das redes e performance das equipes. / Social structures influence team effectiveness. The purpose of this study is to explore the contingencies effects of this relationship by investigating density in distinct network contents on team performance. We first hypothesized opposite direct effects for instrumental and affective density on team performance; then we further argue that task interdependence and power distance orientation act as moderators. To test our hypotheses we use survey data from 27 Emergency and Care Units and 106 teams. The results support the positive effect of instrumental density and the negative impact of affective density. Moreover, task interdependence was found to attenuate both main relationships. We discuss the implications of these findings for research on network density and team performance.

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