Impact of external excitations on the dynamic properties of negative-stiffness vibration Isolation table

This paper presents a study of the efficiency of a negative-stiffness vibration isolation table Minus K 500BM-1 in the frequency range of 2–110 Hz. An overview of other possible methods of vibration isolation is provided. Experimental testing of vibration transmissibility was conducted. Special vibration excitation equipment was tested, which enables the planned studies of the object in question to be carried out

Research of dynamics of the vibration isolation platform

Performance of negative-stiffness vibroisolating table „Minus K500BM-1“ was analyzed in a frequency range of 2-110 Hz. The paper also reviewed other possible ways of vibroisolation. Performed experimental vibrations transmissibility tests were reported as well. A special vibration excitation equipment was tested in research facilities. Subsequently, experimental test methods were described together with presentation of results and conclusions of experimental analysi

Comparable analysis of vibrodiagnostic results of rotary components with different type bearings

"Comparable vibrodiagnostic results of rotor components of technological machines with bearings of tilting-pad journal bearing, sleeve liquid-friction and of roll are given in this work. Sliding of roll of researching technological machines are described; the main characteristics of work and photo are given. Experimental comparable vibrodiagnostics measurements are done. Primary signals of measurement are gotten doing vibrodiagnostic measurements, using different programmable pockets they are transformed to other formats of data. Getting results of measurement are systematized and its analysis is done. Comparison of getting results is done and dependence of work characteristics between rotary systems with bearings of sledding friction and of roll is ascertained. Generalization of results of vibrodiagnostic researches is done and conclusions are formulated in the end of this work

Impact of external excitations on the dynamic properties of negative-stiffness vibration Isolation table

This paper presents a study of the efficiency of a negative-stiffness vibration isolation table Minus K 500BM-1 in the frequency range of 2–110 Hz. An overview of other possible methods of vibration isolation is provided. Experimental testing of vibration transmissibility was conducted. Special vibration excitation equipment was tested, which enables the planned studies of the object in question to be carried out

Research of positioning accuracy of robot MOTOMAN SSF2000

Research of the dynamic properties, positioning precision and repeatability of MOTOMAN SSF2000 movement is presented in this article. Dynamic properties were analyzed using a mobile equipment of measuring „Machine Diagnostic Toolbox Type 9727“ with a DELL notebook. The manipulator vibrations were measured in two robot’s positions: vertical and horizontal, and at three different speeds. The research was made under three different conditions, changing the tool mass and spee

Research of positioning accuracy of robot MOTOMAN SSF2000

Research of the dynamic properties, positioning precision and repeatability of MOTOMAN SSF2000 movement is presented in this article. Dynamic properties were analyzed using a mobile equipment of measuring „Machine Diagnostic Toolbox Type 9727“ with a DELL notebook. The manipulator vibrations were measured in two robot’s positions: vertical and horizontal, and at three different speeds. The research was made under three different conditions, changing the tool mass and spee

Research of positioning accuracy of robot MOTOMAN SSF2000

Research of the dynamic properties, positioning precision and repeatability of MOTOMAN SSF2000 movement is presented in this article. Dynamic properties were analyzed using a mobile equipment of measuring „Machine Diagnostic Toolbox Type 9727“ with a DELL notebook. The manipulator vibrations were measured in two robot’s positions: vertical and horizontal, and at three different speeds. The research was made under three different conditions, changing the tool mass and spee

Loss-of-activity-mutation in the cardiac chloride-bicarbonate exchanger AE3 causes short QT syndrome

Mutations in potassium and calcium channel genes have been associated with cardiac arrhythmias. Here, Jensen et al. show that an anion transporter chloride-bicarbonate exchanger AE3 is also responsible for the genetically-induced mechanism of cardiac arrhythmia, suggesting new therapeutic targets for this diseas

Persistent cAMP-Signals Triggered by Internalized G-Protein–Coupled Receptors

Real-time monitoring of G-protein-coupled receptor (GPCR) signaling in native cells suggests that the receptor for thyroid stimulating hormone remains active after internalization, challenging the current model for GPCR signaling

Conserved expression and functions of PDE4 in rodent and human heart

PDE4 isoenzymes are critical in the control of cAMP signaling in rodent cardiac myocytes. Ablation of PDE4 affects multiple key players in excitation–contraction coupling and predisposes mice to the development of heart failure. As little is known about PDE4 in human heart, we explored to what extent cardiac expression and functions of PDE4 are conserved between rodents and humans. We find considerable similarities including comparable amounts of PDE4 activity expressed, expression of the same PDE4 subtypes and splicing variants, anchoring of PDE4 to the same subcellular compartments and macromolecular signaling complexes, and downregulation of PDE4 activity and protein in heart failure. The major difference between the species is a fivefold higher amount of non-PDE4 activity in human hearts compared to rodents. As a consequence, the effect of PDE4 inactivation is different in rodents and humans. PDE4 inhibition leads to increased phosphorylation of virtually all PKA substrates in mouse cardiomyocytes, but increased phosphorylation of only a restricted number of proteins in human cardiomyocytes. Our findings suggest that PDE4s have a similar role in the local regulation of cAMP signaling in rodent and human heart. However, inhibition of PDE4 has ‘global’ effects on cAMP signaling only in rodent hearts, as PDE4 comprises a large fraction of the total cardiac PDE activity in rodents but not in humans. These differences may explain the distinct pharmacological effects of PDE4 inhibition in rodent and human hearts