Advanced Multi-Body Modelling of DCCSS Isolators: Geometrical Compatibility and Kinematics

The effectiveness of Double Concave Curved Surface Sliders (DCCSS), which initially spread under the name of Double Friction Pendulum (DFP) isolators, was already widely proven by numerous experimental campaigns carried out worldwide. However, many aspects concerning their dynamical behavior still need to be clarified and some details still require improvement and optimization. In particular, due to the boundary geometrical conditions, sliding along the coupled surfaces may not be compliant, where this adjective is adopted to indicate an even distribution of stresses and sliding contact. On the contrary, during an earthquake, the fulfillment of geometrical compatibility between the constitutive bodies naturally gives rise to a very peculiar dynamic behavior, composed of continuous alternation of sticking and slipping phases. Such behavior yields a temporary and cyclic change of topology. Since the constitutive elements can be modelled as rigid bodies, both approaches, namely Compliant Sliding and Stick-Slip, can be numerically modelled by means of techniques typically adopted for multi-body mechanical systems. With the objective of contributing to the understanding and further improvement of this technology, a topology-changing multi-body mechanical model was developed to simulate the DCCSS. In the present work, attention is focused on details regarding geometrical compatibility and kinematics, while the complete dynamics is presented in another work. In particular, for the sake of comparison, the kinematic equations are presented and applied not only for the proposed Stick-Slip approach, but also for the currently accepted Compliant Sliding approach. The main findings are presented and discussed.

Nonstationary separation of Nd and Pr by P507 extractant

The low efficiency of the separation of rare earth metals by extraction on one stage requires the combination of a large number of mixer-settlers in a cascade. The problem of increasing the rare earth elements separation factor is extremely urgent. One of the perspective methods is the nonequilibrium nonstationary process. In this work, it is offered to use the principle of a nonstationary extraction in the separation process of the Nd/Pr pair from chloride medium by the extractant based onP507. The results which have been received by an experimental setup allowing the monitoring of the influence of a cyclic change of physical-chemical parameters on extraction in the online modeare discussed. A comparison of two ways of implementation of extraction in the nonstationary mode is carried out. The apparent values of physical-chemical parameters (ΔG, ΔH, ΔS) in the temperatures range 15-65 °C are calculated from the data of joint extraction of Nd and Pr.

Introduction

In Section 1 of my introduction to this Special Issue, I define the concept of semantic–pragmatic cycles, a relatively recently discovered phenomenon, drawing a distinction between two sub-types: onomasiological and semasiological cycles. Semantic–pragmatic cycles are contrasted with the more widely known (morpho-)syntactic cycles such as the Negative Cycle (or Jespersen Cycle), and I discuss possible connections between these two types of cycles. Finally, I raise some questions for further research. In Section 2, I outline the empirical and/or theoretical contribution of each of the six papers that follow – considering, in particular, how they contribute to elucidating the role of pragmatics in cyclic change.

Safety and efficacy of a hyperaemic agent, intracoronary nicorandil 4mg, for invasive physiological assessments during fractional flow reserve measurement

Background Fractional flow reserve (FFR) is one of most reliable index for the determining the functional severity coronary artery stenosis. Adenosine is the most commonly used agent for maximal hyperaemia. However, adenosine can cause chest discomfort, bronchial hyper-reactivity, and atrioventricular block. The aim of this study is to evaluate the safety and efficacy of intracoronary nicorandil as an alternative hyperaemic agent for FFR. Methods and results We enrolled consecutive 82 patients (87 lesions) who underwent FFR measurement in our center from Nov. 2018. We compared three groups; intravenous infusion of adenosine (150 μg/kg/min); and adenosine added intracoronary nicorandil 2mg; and intracoronary nicorandil 4mg. Mean FFR value was 0.83±0.09, 0.82±0.09, 0.82±0.08, There was a strong correlation among three groups (R2>0.9). Mean cyclic change in FFR was 0.026±0.023, 0.019±0.010, 0.016±0.014, respectively, cyclic change was smallest in intracoronary nicorandil 4mg group (vs ATP; p<0.001, vs ATP + nicorandil 2mg; p<0.001). By Wilcoxon test, mean FFR value of nicorandil 4mg was significant lower than ATP (p=0.0021), and equal to ATP + nicorandil 2mg (p=0.98). Conclusions Intracoronary nicorandil 4mg is a simple, safe, and effective way to induce steady-state hyperaemia for FFR. Figure 1 Funding Acknowledgement Type of funding source: None

Entrainment of the Drosophila clock by the visual system

Circadian clocks evolved as an adaptation to the cyclic change of day and night. To precisely adapt to this environment, the endogenous period has to be adjusted every day to exactly 24 hours by a process called entrainment. Organisms can use several external cues, called zeitgebers, to adapt. These include changes in temperature, humidity, or light. The latter is the most powerful signal to synchronize the clock in animals. Research shows that a complex visual system and circadian photoreceptors work together to adjust animal physiology to the outside world. This review will focus on the importance of the visual system for clock synchronization in the fruit fly Drosophila melanogaster. It will cover behavioral and physiological evidence that supports the importance of the visual system in light entrainment.

On the emergence of personal articles in the history of Catalan

The grammaticalization of personal articles in Ibero-Romance, in general, and in Catalan, in particular, is discussed in this contribution. The personal articles proceed historically from the Latin noun dominus / domina ‘lord, master / lady, madam’, used for society’s upper class, and appear nowadays only with [+human] proper names. Firstly, it developed into an honorific marker in Old Ibero-Romance, and in modern Catalan into a generic personal article without honorific meaning. Their evolution is conceived as a cyclic change, whereby phrasal (adjectival) elements occupying specifier positions first develop into X° heads, and eventually into (clitic) affixes in the form of articles, while the Old Ibero-Romance honorifics are XPs (and not heads). This cyclic change comprises phonological, morphological, syntactic, and also semantic shifts.