The dynamic behavior of a cantilever beam coupled to a non-ideal unbalanced motor through numerical and experimental analysis

An excitation force that is not influenced by the system state is said to be an ideal energy source. In real situations, a direct and feedback coupling between the excitation source and the system must always exist at a certain level. This manifestation of the law of conservation of energy is known as the Sommerfeld effect. In the case of obtaining a mathematical model for such a system, additional equations are usually necessary to describe the vibration sources with limited power and its coupling with the mechanical system. In this work, a cantilever beam and a non-ideal DC motor fixed to its free end are analyzed. The motor has an unbalanced mass that provides excitation to the system which is proportional to the current applied to the motor. During the coast up operation of the motor, if the drive power is increased slowly, making the excitation frequency pass through the first natural frequency of the beam, the DC motor speed will remain the same until it suddenly jumps to a much higher value (simultaneously its amplitude jumps to a much lower value) upon exceeding a critical input power. It was found that the Sommerfeld effect depends on some system parameters and the motor operational procedures. These parameters are explored to avoid the resonance capture in the Sommerfeld effect. Numerical simulations and experimental tests are used to help gather insight of this dynamic behavior. (C) 2014 Elsevier Ltd. All rights reserved.

Nonlinear dynamics and control strategies: On a energy harvester vibrating system with a linear form to non-ideal motor torque

In this paper, we deal with the research of a vibrating model of an energy harvester device, including the nonlinearities in the model of the piezoelectric coupling and the non-ideal excitation. We show, using numerical simulations, in the analysis of the dynamic responses, that the harvested power is influenced by non-linear vibrations of the structure. Chaotic behavior was also observed, causing of the loss of energy throughout the simulation time. Using a perturbation technique, we find an approximate analytical solution for the non-ideal system. Then, we apply both two control techniques, to keep the considered system, into a stable condition. Both the State Dependent Ricatti Equation (SDRE) control as the feedback control by changing the energy of the oscillator, were efficient in controlling of the considered non-ideal system.

The role of the state in health public policies: an overview of the debate on the concept of State and the Brazilian case

This article is the result of a narrative literature review. The objective is to show the development of an overview on the ideological debate on the design of state health policies. We argue that the role of the state in the development of health policy, even under the pressure of the global market, may create alternatives to promote and drive economic and social development, meaning they are not subject to economic constraints imposed by the liberal ideal of market. Here is a part of a theoretical discussion about the construction and presence of the State in Latin America, particularly in Brazil. We take the approaches of the Marxist tradition and liberal to the issue as reference. This discussion allows us to understand the historical role of the state in the maintenance of social policies, specifically health, is an alternative to public control eases the intense capital mobility promoted by economic globalization. In this sense, the theme makes the Brazilian health an important issue of social sciences, why is the historicity of the construction of the Brazilian health system, as a public policy that can mirror the actual reconstruction of the institutional framework of the Brazilian state with the establishment instances of negotiation between the various spheres of power that strengthen the state in this process of democratization of Brazilian society.

On suppression of chaotic motions of a portal frame structure under non-ideal loading using a magneto-rheological damper

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dinâmica não linear e controle de um sistema vibratório modelado com memória de forma e, excitado por fontes de energia do tipo ideal e não ideal

Pós-graduação em Engenharia Mecânica - FEB

The State as Part of the Republic

The State as Part of the Republic The main objective of this article is to analyze an ideal of civic life, the Republic, based on the form of the sovereign state. Historically, the convergence between Republic and sovereign state has been truncated by the former's commitment to the thesis of royal absolutism. However, as the democratic issue (translated in the values of equality and pluralism) was absorbed by sovereignism, such convergence became more plausible. As viewed in this article, the theoretical bridge of that passage is the concept of political representation. The issue is thus to show in what way a certain vision of the political form (that of the state) can fit into a theory of political representation that contemplates the above-mentioned values.

Residence Time Distribution Models Derived from Non-Ideal Laminar Velocity Profiles in Tubes

The theoretical E-curve for the laminar flow of non-Newtonian fluids in circular tubes may not be accurate for real tubular systems with diffusion, mechanical vibration, wall roughness, pipe fittings, curves, coils, or corrugated walls. Deviations from the idealized laminar flow reactor (LFR) cannot be well represented using the axial dispersion or the tanks-in-series models of residence time distribution (RTD). In this work, four RTD models derived from non-ideal velocity profiles in segregated tube flow are proposed. They were used to represent the RTD of three tubular systems working with Newtonian and pseudoplastic fluids. Other RTD models were considered for comparison. The proposed models provided good adjustments, and it was possible to determine the active volumes. It is expected that these models can be useful for the analysis of LFR or for the evaluation of continuous thermal processing of viscous foods.

The Emergence of the Post-Socialist Welfare State - The Case of the Baltic States : Estonia, Latvia and Lithuania

This dissertation takes a step towards providing a better understanding of post-socialist welfare state development from a theoretical as well as an empirical perspective. The overall analytical goal of this thesis has been to critically assess the development of social policies in Estonia, Latvia and Lithuania using them as illustrative examples of post-socialist welfare state development in the light of the theories, approaches and typologies that have been developed to study affluent capitalist democracies. The four studies included in this dissertation aspire to a common aim in a number of specific ways. The first study tries to place the ideal-typical welfare state models of the Baltic States within the well-known welfare state typologies. At the same time, it provides a rich overview of the main social security institutions in the three countries by comparing them with each other and with the previous structures of the Soviet period. It examines the social insurance institutions of the Baltic States (old-age pensions, unemployment insurance, short-term benefits, sickness, maternity and parental insurance and family benefits) with respect to conditions of eligibility, replacement rates, financing and contributions. The findings of this study indicate that the Latvian social security system can generally be labelled as a mix of the basic security and corporatist models. The Estonian social security system can generally also be characterised as a mix of the basic security and corporatist models, even if there are some weak elements of the targeted model in it. It appears that the institutional changes developing in the social security system of Lithuania have led to a combination of the basic security and targeted models of the welfare state. Nevertheless, as the example of the three Baltic States shows, there is diversity in how these countries solve problems within the field of social policy. In studying the social security schemes in detail, some common features were found that could be attributed to all three countries. Therefore, the critical analysis of the main social security institutions of the Baltic States in this study gave strong supporting evidence in favour of identifying the post-socialist regime type that is already gaining acceptance within comparative welfare state research. Study Two compares the system of social maintenance and insurance in the Soviet Union, which was in force in the three Baltic countries before their independence, with the currently existing social security systems. The aim of the essay is to highlight the forces that have influenced the transformation of the social policy from its former highly universal, albeit authoritarian, form, to the less universal, social insurance-based systems of present-day Estonia, Latvia and Lithuania. This study demonstrates that the welfare–economy nexus is not the only important factor in the development of social programs. The results of this analysis revealed that people's attitudes towards distributive justice and the developmental level of civil society also play an important part in shaping social policies. The shift to individualism in people’s mentality and the decline of the labour movement, or, to be more precise, the decline in trade union membership and influence, does nothing to promote the development of social rights in the Baltic countries and hinders the expansion of social policies. The legacy of the past has been another important factor in shaping social programs. It can be concluded that social policy should be studied as if embedded not only in the welfare-economy nexus, but also in the societal, historical and cultural nexus of a given society. Study Three discusses the views of the state elites on family policy within a wider theoretical setting covering family policy and social policy in a broader sense and attempts to expand this analytical framework to include other post-socialist countries. The aim of this essay is to explore the various views of the state elites in the Baltics concerning family policy and, in particular, family benefits as one of the possible explanations for the observed policy differences. The qualitative analyses indicate that the Baltic States differ significantly with regard to the motives behind their family policies. Lithuanian decision-makers seek to reduce poverty among families with children and enhance the parents’ responsibility for bringing up their children. Latvian policy-makers act so as to increase the birth rate and create equal opportunities for children from all families. Estonian policy-makers seek to create equal opportunities for all children and the desire to enhance gender equality is more visible in the case of Estonia in comparison with the other two countries. It is strongly arguable that there is a link between the underlying motives and the kinds of family benefits in a given country. This study, thus, indicates how intimately the attitudes of the state bureaucrats, policy-makers, political elite and researchers shape social policy. It confirms that family policy is a product of the prevailing ideology within a country, while the potential influence of globalisation and Europeanisation is detectable too. The final essay takes into account the opinions of welfare users and examines the performances of the institutionalised family benefits by relying on the recipients’ opinions regarding these benefits. The opinions of the populations as a whole regarding government efforts to help families are compared with those of the welfare users. Various family benefits are evaluated according to the recipients' satisfaction with those benefits as well as the contemporaneous levels of subjective satisfaction with the welfare programs related to the absolute level of expenditure on each program. The findings of this paper indicate that, in Latvia, people experience a lower level of success regarding state-run family insurance institutions, as compared to those in Lithuania and Estonia. This is deemed to be because the cash benefits for families and children in Latvia are, on average, seen as marginally influencing the overall financial situation of the families concerned. In Lithuania and Estonia, the overwhelming majority think that the family benefit systems improve the financial situation of families. It appears that recipients evaluated universal family benefits as less positive than targeted benefits. Some universal benefits negatively influenced the level of general satisfaction with the family benefits system provided in the countries being researched. This study puts forward a discussion about whether universalism is always more legitimate than targeting. In transitional economies, in which resources are highly constrained, some forms of universal benefits could turn out to be very expensive in relative terms, without being seen as useful or legitimate forms of help to families. In sum, by closely examining the different aspects of social policy, this dissertation goes beyond the over-generalisation of Eastern European welfare state development and, instead, takes a more detailed look at what is really going on in these countries through the examples of Lithuania, Latvia and Estonia. In addition, another important contribution made by this study is that it revives ‘western’ theoretical knowledge through ‘eastern’ empirical evidence and provides the opportunity to expand the theoretical framework for post-socialist societies.

Swiss Alps Jungfrau Aletsch UNESCO World Heritage Site - The state of this World Heritage region as a starting point for regional monitoring

The UNESCO listing as World Heritage Site confirms the outstanding qualities of the high-mountain region around the Great Aletsch Glacier. The region of the World Heritage Site now faces the responsibility to make these qualities visible and to preserve them for future generations. Consequently the qualities of the site must not be regarded in isolation but in the context of the entire region with its dynamics and developments. Regional monitoring is the observation and evaluation of temporal changes in target variables. It is thus an obligation towards UNESCO, who demands regular reports about the state of the listed World Heritage assets. It also allows statements about sustainable regional development and can be the basis for early recognition of threats to the outstanding qualities. Monitoring programmes face three major challenges: first, great care must be taken in defining the target qualities to be monitored or the monitoring would remain vague. Secondly, the selection of ideal indicators to describe these qualities is impeded by inadequate data quality and availability, compromises are inevitable. Thirdly, there is always an element of insecurity in the interpretation of the results as to what influences and determines the changes in the target qualities. The first survey of the monitoring programme confirmed the exceptional qualities of the region and also highlighted problematic issues.

Solid-State Compatibilization of Immiscible Polymer Blends: Cryogenic Milling and Solid-State Shear Pulverization

The blending of common polymers allows for the rapid and facile synthesis of new materials with highly tunable properties at a fraction of the costs of new monomer development and synthesis. Most blends of polymers, however, are completely immiscible and separate into distinct phases with minimal phase interaction, severelydegrading the performance of the material. Cross-phase interactions and property enhancement can be achieved with these blends through reactive processing or compatibilizer addition. A new class of blend compatibilization relies on the mechanochemical reactions between polymer chains via solid-state, high energy processing. Two contrasting mechanochemical processing techniques are explored in this thesis: cryogenic milling and solid-state shear pulverization (SSSP). Cryogenic milling is a batch process where a milling rod rapidly impacts the blend sample while submerged within a bath of liquid nitrogen. In contrast, SSSP is a continuous process where blend components are subjected to high shear and compressive forces while progressing down a chilled twin-screw barrel. In the cryogenic milling study, through the application of a synthesized labeledpolymer, in situ formation of copolymers was observed for the first time. The microstructures of polystyrene/high-density polyethylene (PS/HDPE) blends fabricated via cryomilling followed by intimate melt-state mixing and static annealing were found to be morphologically stable over time. PS/HDPE blends fabricated via SSSP also showed compatibilization by way of ideal blend morphology through growth mechanisms with slightly different behavior compared to the cryomilled blends. The new Bucknell University SSSP instrument was carefully analyzed and optimized to produce compatibilized polymer blends through a full-factorial experiment. Finally, blends of varying levels of compatibilization were subjected to common material tests to determine alternative means of measuring and quantifying compatibilization,

Diesel spray mixing limited vaporization with non-ideal and multi-component fuel thermophysical property effects

Internal combustion engines are, and will continue to be, a primary mode of power generation for ground transportation. Challenges exist in meeting fuel consumption regulations and emission standards while upholding performance, as fuel prices rise, and resource depletion and environmental impacts are of increasing concern. Diesel engines are advantageous due to their inherent efficiency advantage over spark ignition engines; however, their NOx and soot emissions can be difficult to control and reduce due to an inherent tradeoff. Diesel combustion is spray and mixing controlled providing an intrinsic link between spray and emissions, motivating detailed, fundamental studies on spray, vaporization, mixing, and combustion characteristics under engine relevant conditions. An optical combustion vessel facility has been developed at Michigan Technological University for these studies, with detailed tests and analysis being conducted. In this combustion vessel facility a preburn procedure for thermodynamic state generation is used, and validated using chemical kinetics modeling both for the MTU vessel, and institutions comprising the Engine Combustion Network international collaborative research initiative. It is shown that minor species produced are representative of modern diesel engines running exhaust gas recirculation and do not impact the autoignition of n-heptane. Diesel spray testing of a high-pressure (2000 bar) multi-hole injector is undertaken including non-vaporizing, vaporizing, and combusting tests, with sprays characterized using Mie back scatter imaging diagnostics. Liquid phase spray parameter trends agree with literature. Fluctuations in liquid length about a quasi-steady value are quantified, along with plume to plume variations. Hypotheses are developed for their causes including fuel pressure fluctuations, nozzle cavitation, internal injector flow and geometry, chamber temperature gradients, and turbulence. These are explored using a mixing limited vaporization model with an equation of state approach for thermopyhysical properties. This model is also applied to single and multi-component surrogates. Results include the development of the combustion research facility and validated thermodynamic state generation procedure. The developed equation of state approach provides application for improving surrogate fuels, both single and multi-component, in terms of diesel spray liquid length, with knowledge of only critical fuel properties. Experimental studies are coupled with modeling incorporating improved thermodynamic non-ideal gas and fuel

Three-dimensional magnetic resonance observation of cartilage repair tissue (MOCART) score assessed with an isotropic three-dimensional true fast imaging with steady-state precession sequence at 3.0 Tesla

INTRODUCTION: Cartilage defects are common pathologies and surgical cartilage repair shows promising results. In its postoperative evaluation, the magnetic resonance observation of cartilage repair tissue (MOCART) score, using different variables to describe the constitution of the cartilage repair tissue and the surrounding structures, is widely used. High-field magnetic resonance imaging (MRI) and 3-dimensional (3D) isotropic sequences may combine ideal preconditions to enhance the diagnostic performance of cartilage imaging.Aim of this study was to introduce an improved 3D MOCART score using the possibilities of an isotropic 3D true fast imaging with steady-state precession (True-FISP) sequence in the postoperative evaluation of patients after matrix-associated autologous chondrocyte transplantation (MACT) as well as to compare the results to the conventional 2D MOCART score using standard MR sequences. MATERIAL AND METHODS: The study had approval by the local ethics commission. One hundred consecutive MR scans in 60 patients at standard follow-up intervals of 1, 3, 6, 12, 24, and 60 months after MACT of the knee joint were prospectively included. The mean follow-up interval of this cross-sectional evaluation was 21.4 +/- 20.6 months; the mean age of the patients was 35.8 +/- 9.4 years. MRI was performed at a 3.0 Tesla unit. All variables of the standard 2D MOCART score where part of the new 3D MOCART score. Furthermore, additional variables and options were included with the aims to use the capabilities of isotropic MRI, to include the results of recent studies, and to adapt to the needs of patients and physician in a clinical routine examination. A proton-density turbo spin-echo sequence, a T2-weighted dual fast spin-echo (dual-FSE) sequence, and a T1-weighted turbo inversion recovery magnitude (TIRM) sequence were used to assess the standard 2D MOCART score; an isotropic 3D-TrueFISP sequence was prepared to evaluate the new 3D MOCART score. All 9 variables of the 2D MOCART score were compared with the corresponding variables obtained by the 3D MOCART score using the Pearson correlation coefficient; additionally the subjective quality and possible artifacts of the MR sequences were analyzed. RESULTS: The correlation between the standard 2D MOCART score and the new 3D MOCART showed for the 8 variables "defect fill," "cartilage interface," "surface," "adhesions," "structure," "signal intensity," "subchondral lamina," and "effusion"-a highly significant (P < 0.001) correlation with a Pearson coefficient between 0.566 and 0.932. The variable "bone marrow edema" correlated significantly (P < 0.05; Pearson coefficient: 0.257). The subjective quality of the 3 standard MR sequences was comparable to the isotropic 3D-TrueFISP sequence. Artifacts were more frequently visible within the 3D-TrueFISP sequence. CONCLUSION: In the clinical routine follow-up after cartilage repair, the 3D MOCART score, assessed by only 1 high-resolution isotropic MR sequence, provides comparable information than the standard 2D MOCART score. Hence, the new 3D MOCART score has the potential to combine the information of the standard 2D MOCART score with the possible advantages of isotropic 3D MRI at high-field. A clear limitation of the 3D-TrueFISP sequence was the high number of artifacts. Future studies have to prove the clinical benefits of a 3D MOCART score.

Iowa State Daily (July 12, 2012)

ContentsPoll: Ideal study abroad location?One-on-one: Samantha WeeseEditorial: Cameras in CampustownISU collides with CERN's discoveriesIowa Games takes new direction

Vordere Kreuzband-OP-Technik: «State of the Art» und Zukunft

Die Behandlung der vorderen Kreuzbandverletzung stellt die Chirurgie seit vielen Jahren vor grosse Herausforderungen. Die Geschichte der Kreuzbandchirurgie ist im Wesentlichen geprägt von der Suche nach dem perfekten Transplantat und dem operativen Fortschritt. In diesem Übersichtssartikel werden die aktuellen chirurgischen Strategien erörtert und ein Blick in die Zukunft gewagt.

State health care reform: An analysis of strategies

The United States health care system faces significant challenges, particularly with problems of the uninsured and with the rising costs of care. These problems lead many to study and discuss strategies for reforming the health care system. Four different plans for ideal health care reform, set forth by notable scholars or organizations, are explained herein. Then, states within the United States are examined in terms of their recent efforts at health care reform. Those states proposing significant changes to their health care systems are analyzed—namely, Maine, Massachusetts, and Vermont. The strategies used in these three states are compared to the strategies laid out by the experts in order to determine which strategies are the most popular in current health care reform efforts among the states studied here. These strategies are totaled to find which organization's plan for ideal reform seems to be the most popular. The strategies of managed competition are shown to be the most popular strategies among these three state health care reforms, while the strategies of the single-payer plan discussed herein were the least popular. All three states seem to utilize strategies that build upon their previous health care system, rather than implementing strategies that completely replace the previous system. ^