[en] EF-hand proteins can be activated by the binding of various heavy metals other than calcium, and such complexes can disturb the calcium-signaling pathway and cause toxicity and disease causing state. So far, no comprehensive study has been done to understand different heavy metals binding to calcium signaling proteins. Energetically, Ca²⁺ is preferred in three sites, while in one site Ba²⁺ has better binding energy. The Sr²⁺-coordination in the EF hand motifs is similar to that of the native Ca²⁺ bound structure, except for the lack of water coordination. Sr²⁺-coordination seems to be a pre-formed in nature since all seven coordinating atoms are from the protein itself, which also correlates with entropy contributions in Sr²⁺ binding. These findings improve our understanding of metal association with calcium binding proteins and of metal induced conformational changes.

[en] In this study, the effect of prestressed strand diameters, providing the beam-to-column connections, was investigated from both experimental and analytical aspects. In the experimental studies, the strength, stiffness and energy dissipation capacities of the precast specimens comprising two prestressed strand samples of 12.70 mm and 15.24 mm diameters, were compared with the reference specimen. The precast specimen with strands of 15.24 mm reached 96% of the maximum strength of the reference specimen; the amount of energy dissipated by this specimen by the end of the experiment reached 48% of the amount of energy dissipated by the reference sample; and the stiffness of the same specimen at a drift of 1.5% reached 77% of the stiffness of the reference specimen at this drift. Parallel results were obtained during the analytical studies from the aspects of strength and behavior, but the initial stiffness of the analytical models was lower than that of the test specimens.

[en] The mechanical design and analysis of the LCLS II 2 K cold box are presented. Its feature and functionality are discussed. ASME B31.3 was used to design its internal piping, and compliance of the piping code was ensured through flexibility analysis. The 2 K cold box was analyzed using ANSYS 17.2; the requirements of the applicable codes—ASME Section VIII Division 2 and ASCE 7-10—were satisfied. Seismic load was explicitly considered in both analyses. (paper)

[en] This research use of lime filler Sukaraja expected add durability layers of concrete pavement is asphalt damage caused by the weather and load traffic. This study attempts to know how much value characteristic Marshall on a mixture of concrete asphalt using lime filler. This research uses experimental methods that is with a pilot to get results, thus will look filler utilization lime on construction concrete asphalt variation in filler levels 2 %, 3 %, 4 %.The results showed that the use of lime filler will affect characteristic a mixture of concrete asphalt. The more filler chalk used to increase the value of stability. On the cretaceous filler 2 % value of stability is 1067,04 kg. When lime filler levels added to the levels of filler 4 %, the value of stability increased to 1213,92 kg. The flexibility increased the number of filler as levels lime 2 % to 4 % suggests that are conducted more stiff mix. (paper)

[en] Highlights: • We describe an exquisite photomechanical effect observed in an azobenzene-Gd(III) MOF. • The single crystals of this material display complex motion. • This work outlines a direction of MOF-based photomechanical motion. -- Abstract: Photo-response molecular-scale movement has been well developed in azobenzene photochromic molecules. However, material capable of converting this molecular-scale movement to macroscopic work remains a formidable challenge. Here, we describe an exquisite photomechanical effect observed in an azobenzene-Gd(III) MOF. The single crystal of this material displays complex motion including walking, rolling, self-rotating, swing, and finally popping, dependent on the exposed time under UV and the size of the crystals. Consequently, this functional material gives the direct and impressive evidence to support the potential of MOF material in photomechanical motion.

[en] The authors have addressed the change of main cable tensioning force as the means of suspension bridge stiffness control. An ANSYS 3D model of a suspension bridge was developed. The dead load stress-strain behaviour and dynamic response of the model were analyzed. The study has shown that 7.5 fold increase of the main cable pre-tensioning force reduced the displacement in the middle of the central span of the stiffening girder by 40%, while in the middle of the end span, a 9% increase in displacement was observed; and displacement of the tower apex reduced by 28%. Modal analysis has shown that the main cable pre-tensioning force in the 3D model had effect neither on the natural vibration frequency spectrum of the structure, nor on the distribution of the principal modes in the spectrum. With a 7.5 fold increase of the main cable pre-tensioning force, the values of natural fundamental frequencies have changed within 2% range. The results obtained by the authors allow for the conclusion that varying the pre-tensioning force of the main cable has little effect on a suspension bridge dynamic response control. At the same time, pre-tensioning of the main cable allows control over the stiffness of the hybrid cross-tie system. (paper)

[en] The transverse impact characteristics of a rubber pipe expansion joint are studied. A pair of joints assembled end to end with an inserted middle mass is tested on a drop shock testing machine. Based on the test results, an equivalent fixed-fixed beam model with polynomial stiffness and damping is applied to predict the transverse impact response and identify the nonlinear impact parameters. The least square residual between the computed and test results is defined to drive the identification optimization. The response surface methodology in combination with the generalized reduced gradient method is used to search the best matching coefficients. Final results show that the equivalent bending stiffness of the tested rubber expansion joint gradually decreases with the transverse deformation and is greatly influenced by its internal working pressure

[en] Constitutive models based on a non-associated flow rule (non-AFR) have received increased attention due to their flexibility in capturing laboratory experiments. On the other hand, the recently proposed Fourier Asymmetric Yield (FAY) model enables the definition of convex yield functions with arbitrary complexity, which can be used in conjunction to an associated flow rule and nevertheless accurately match experimental data. The present contribution aims comparing AFR and non-AFR based approaches with respect to their ability in capturing measured strain fields in controlled Nakajima experiments. It is shown that a sufficiently flexible yield function is able of delivering accurate results without having to renounce to restrictions such as flow rule association or convexity. The analysis is carried out using two common deep drawing materials, namely an AA6016 and a steel grade DC05. (paper)

[en] A model is established to minimize the maximum nodal displacement. The nodal displacement of an adaptive truss can be control by this model. Examples illustrate that the truss nodal displacements can be controlled by this method. This model can be used to reduced the nodal displacements, and the maximum stress in an indeterminate truss can be reduced simultaneously

[en] Antagonistic muscle pairs pulling on a joint are in general able to modulate stiffness through co-activation. Closer analysis of the stiffness, however, shows that, depending on the muscle and joint parameters, domains might occur in joint angle space for which stiffness variation is limited (low stiffness variability) or even impossible (stiffness nodes). As a consequence, stiffness control utilizing pure co-activation might fail. This work presents novel strategies for simultaneous control of torque and stiffness in a hinge joint actuated by two antagonistic muscle pairs. One strategy handles stiffness nodes by shifting them away from the current joint position and thus regaining stiffness controllability. To prevent domains of low stiffness variation, an optimal muscle configuration is sought and finally defined which allows for a maximal stiffness variation across a wide joint angle range. Based on this optimal configuration, four additional control strategies are proposed and tested which deliver stiffnesses and torques comparable to those obtained in the optimal case. The strategies combine torque control and stiffness control by co-activation with novel ideas like activation overflow and an inverse model approach. All strategies are tested in simulation and the results are compared with those of the optimal setup.