A flexure hinge is a flexible connector that can provide a limited rotational motion between two rigid parts by means of material deformation. These connectors can be used to substitute traditional kinematic pairs (like bearing couplings) in rigid-body mechanisms. When compared to their rigid-body counterpart, flexure hinges are characterized by reduced weight, absence of backlash and friction, part-count reduction, but restricted range of motion. There are several types of flexure hinges in the literature that have been studied and characterized for different applications. In our study, we have introduced new types of flexures with curved structures i.e. circularly curved-beam flexures and spherical flexures. These flexures have been utilized for both planar applications (e.g. articulated robotic fingers) and spatial applications (e.g. spherical compliant mechanisms). We have derived closed-form compliance equations for both circularly curved-beam flexures and spherical flexures. Each element of the spatial compliance matrix is analytically computed as a function of hinge dimensions and employed material. The theoretical model is then validated by comparing analytical data with the results obtained through Finite Element Analysis. A case study is also presented for each class of flexures, concerning the potential applications in the optimal design of planar and spatial compliant mechanisms. Each case study is followed by comparing the performance of these novel flexures with the performance of commonly used geometries in terms of principle compliance factors, parasitic motions and maximum stress demands. Furthermore, we have extended our study to the design and analysis of serial and parallel compliant mechanisms, where the proposed flexures have been employed to achieve spatial motions e.g. compliant spherical joints.

Because of the Agreement on Agriculture’s (AoA) Article 13, dubbed the “Peace Clause,” the challengeability of agricultural subsidies has been limited; Article 13 had the power to prevent several types of legal challenges. The Peace Clause has expired, and now many agricultural subsidies can be challenged under substantive provisions of the General Agreement on Tariffs and Trade (GATT 1994) and the Agreement on Subsidies and Countervailing Measures (SCM Agreement). However, there has been some uncertainty, because the new arrangement of agricultural subsidies’ challengeability is being defined by the interpretation and correlation of three different WTO agreements. This study verified, using a two-pronged method, that there is no conflict among the GATT 1994, the SCM Agreement and the AoA, and for this reason, they have to be applied together to regulate agricultural subsidies. This does not mean that all SCM Agreement provisions are automatically applied to agricultural subsidies, with a consequent free ride for challenges to agricultural subsidies. A successful challenge still has to overcome the SCM Agreement’s higher thresholds for challengeability compared with those of the GATT 1994 period. This condemnation became more difficult after the implementation of the WTO. Consequently, the goals established in the AoA of substantial and progressive reductions in agricultural support and protection still have to be accomplished.

While numerous studies have linked family routines to pediatric asthma outcomes, it remains unclear how family routines come to be associated with these outcomes on a biological level. The current study investigated whether longitudinal trajectories of inflammatory markers of asthma could be predicted by levels of family routines in youth with asthma. Family routines were assessed at baseline through parent questionnaires and peripheral blood samples obtained from youth every 6 months (total number of assessments = 4) over the course of an 18 month study period. Youth with more family routines in their home environment showed decreases in mitogen-stimulated production of a cytokine implicated in asthma, IL-13, over the course of the study period. In turn, within-person analyses indicated that at times when stimulated production of IL-13 was high, asthma symptoms were also high, pointing to the clinical relevance of changes in IL-13 over time. A variety of potential explanations for this effect were probed. Parental depression, stress, and general family functioning could not explain these effects, suggesting that family routines are not just a proxy for parent psychological traits or family relationship quality. However, medication use eliminated the relationship between family routines and stimulated production of IL-13. This suggests that family routines do impact asthma outcomes at the biological level, possibly through influencing medication adherence. Considering daily family behaviors when treating asthma may help improve both biological and clinical profiles in youth with asthma.

Zsfassung in engl. Sprache. - Würzburg, Univ., Diss., 2008

Vollst. zugl.: Basel, Universiẗat, Diss., 2008.

John Paul MacDuffie and Frits Pil. / Originally published in the Working paper series of the MIT International Motor Vehicle Program. / Includes bibliographical references (p. 21-22).

Andrew R. Gurbaxani. / Includes bibliographical references (p. 125). / Funded by the IBM Corp.

Christopher J. Voisey. / Includes bibliographical references (p. 41-43).

Kentaro Nobeoka and Michael A. Cusumano. / Includes bibliographical references (p. 24-25). / Supported by the Sloan Foundation and the International Motor Vehicle Program (IMVP) at the Massachusetts Institute of Technology.

The evaluation of the knee joint behavior is fundamental in many applications, such as joint modeling, prosthesis and orthosis design. In-vitro tests are important in order to analyse knee behavior when simulating various loading conditions and studying physiology of the joint. A new test rig for in-vitro evaluation of the knee joint behavior is presented in this paper. It represents the evolution of a previously proposed rig, designed to overcome its principal limitations and to improve its performances. The design procedure and the adopted solution in order to satisfy the specifications are presented here. Thanks to its 6-6 Gough-Stewart parallel manipulator loading system, the rig replicates general loading conditions, like daily actions or clinical tests, on the specimen in a wide range of flexion angles. The restraining actions of knee muscles can be simulated when active actions are simulated. The joint motion in response to the applied loads, guided by passive articular structures and muscles, is permitted by the characteristics of the loading system which is force controlled. The new test rig guarantees visibility so that motion can be measured by an optoelectronic system. Furthermore, the control system of the new test rig allows the estimation of the contribution of the principal leg muscles in guaranteeing the equilibrium of the joint by the system for muscle simulation. Accuracy in positioning is guaranteed by the designed tibia and femur fixation systems,which allow unmounting and remounting the specimen in the same pose. The test rig presented in this paper permits the analysis of the behavior of the knee joint and comparative analysis on the same specimen before and after surgery, in a way to assess the goodness of prostheses or surgical treatments.