Dimensional analysis of natural vibrations of planar multilink flexible robots with elastic constraints at actuator gearhead shaft–link couplings

Abstract: Non-dimensional variables are very useful as they reduce the number of variables when analyzing physical phenomenon. In this paper, the solutions to the frequency equation of multilink flexible robots with elastic constraints is analyzed in a compact form using the dimensional analysis. First, dimensionless governing differential equation of motion is presented. Second, dimensionless boundary conditions are obtained. Third, the dimensionless frequency equation and the orthogonality conditions among the mode shapes are derived. Fourth, some degenerate cases are developed and compared against some existing models. Finally, dimensionless wave numbers are plotted for various joint stiffness ratio to show the influence of various dimensionless parameters on the natural vibrational behavior of the planar multilink flexible robots

Homogeneous and heterogeneous chemistry along air parcel trajectories

The study of coupled heterogeneous and homogeneous chemistry due to polar stratospheric clouds (PSC's) using Lagrangian parcel trajectories for interpretation of the Airborne Arctic Stratosphere Experiment (AASE) is discussed. This approach represents an attempt to quantitatively model the physical and chemical perturbation to stratospheric composition due to formation of PSC's using the fullest possible representation of the relevant processes. Further, the meteorological fields from the United Kingdom Meteorological office global model were used to deduce potential vorticity and inferred regions of PSC's as an input to flight planning during AASE

Modelling the influence of machined surface roughness on the fatigue life of aluminium alloy

The influence of machined surface roughness on the fatigue life of 7010 aluminium alloy has been investigated. Four-point bending specimen have been machined according to various machining conditions and tested in fatigue. In order to explain the high dependence of SN curves on the surface roughness of the specimen, an approach based on the finite element analysis of measured surface topography is proposed. Surface grooves due to machining are supposed to generate stress concentrations that are so calculated. A model of fatigue life prediction is developed, using this definition of local Kt

An intergenic non-coding RNA targets and regulates the ribosome in H. volcanii.

As translation is the final step in gene expression it is particularly important to understand the processes involved in translation regulation. It was shown in the last years that a class of RNA, the nonprotein-coding RNAs (ncRNAs), is involved in regulation of gene expression via various mechanisms (e.g. gene silencing by microRNAs). Almost all of these ncRNA discovered so far target the mRNA in order to modulate protein biosynthesis, this is rather unexpected considering the crucial role of the ribosome during gene expression. However, recent data from our laboratory showed that there is a new class of ncRNAs, which target the ribosome itself [Gebetsberger et al., 2012/ Pircher et al, 2014]. These so called ribosome-associated ncRNAs (rancRNAs) have an impact on translation regulation, mainly by interfering / modulating the rate of protein biosynthesis. The main goal of this project is to identify and describe novel potential regulatory rancRNAs in H. volcanii with the focus on intergenic candidates. Northern blot analyses already revealed interactions with the ribosome and showed differential expression of rancRNAs during different growth phases or under specific stress conditions. To investigate the biological relevance of these rancRNAs, knock-outs were generated in H. volcanii which were used for phenotypic characterization studies. The rancRNA s194 showed association with the 50S ribosomal subunit in vitro and in vivo and was capable of inhibiting peptide bond formation. These preliminary data for the rancRNA s194 make it an interesting candidate for further functional studies to identify the molecular mechanisms by which rancRNAs can modulate protein biosynthesis. Characterization of further rancRNA candidates are also underway

News from Hope College, Volume 20.2: October, 1988

https://digitalcommons.hope.edu/news_from_hope_college/1080/thumbnail.jp

La Red de seguimiento de bólidos y meteoros de la SMA

Se exponen los algoritmos matemáticos desarrollados para la detección, cálculo de trayectoria atmosférica y elementos orbitales de los bólidos y meteoros registrados por la Red de la SMAUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Mutually Consistent Expectations and the Nash Bargaining Problem

The Nash bargaining problem is considered as a game played by two expected-utility maximizers with prior probability distributions over the opponent\u27s strategy set. A natural requirement of mutual consistency and interchangeability of pairs of priors is shown to be necessary and sufficient to single out the only distribution that generates the equivalence of the expected utility maximization and the Nash product maximization

Pengaruh Beban Kerja dan Ketidakjelasan Peran Terhadap Kinerja Pemeriksa Dengan Stres Kerja Sebagai Variabel Mediasi Pada Badan Pemeriksa Keuangan Perwakilan Provinsi Sumatera Barat

Penelitian ini bertujuan mengetahui pengaruh beban kerja dan ketidakjelasan peran terhadap kinerja pemeriksa dengan stres kerja sebagai variabel mediasi. Penelitian ini dilaksanakan pada Badan Pemeriksa Keuangan Perwakilan Provinsi Sumatera Barat. Sampel penelitian ini sebanyak 54 orang. Pengolahan data penelitian dilakukan dengan metode Structural Equation Modelling (SEM) dengan bantuan software SmartPLS 3.0. Hasil penelitian menunjukkan bahwa 1) beban kerja berpengaruh negatif dan signifikan terhadap kinerja, 2) ketidakjelasan peran berpengaruh negatif dan signifikan terhadap kinerja, 3) beban kerja berpengaruh positif dan signifikan terhadap stres kerja, 4) ketidakjelasan peran tidak berpengaruh signifikan terhadap stres kerja, 5) stres kerja berpengaruh positif dan signifikan terhadap kinerja, 6) stres kerja tidak memediasi hubungan antara beban kerja dengan kinerja, dan 7) stres kerja tidak memediasi hubungan antara ketidakjelasan peran dengan kinerja. Kata kunci: Beban Kerja; Ketidakjelasan Peran; Stres Kerja; Kinerj