A dual-mass resonant mems gyroscope design with electrostatic tuning for frequency mismatch compensation

The micro-electro-mechanical systems (MEMS)-based sensor technologies are considered to be the enabling factor for the future development of smart sensing applications, mainly due to their small size, low power consumption and relatively low cost. This paper presents a new structurally and thermally stable design of a resonant mode-matched electrostatic z-axis MEMS gyroscope considering the foundry constraints of relatively low cost and commercially available silicon-on-insulator multi-user MEMS processes (SOIMUMPs) microfabrication process. The novelty of the proposed MEMS gyroscope design lies in the implementation of two separate masses for the drive and sense axis using a unique mechanical spring configuration that allows minimizing the cross-axis coupling between the drive and sense modes. For frequency mismatch compensation between the drive and sense modes due to foundry process uncertainties and gyroscope operating temperature variations, a comb-drive-based electrostatic tuning is implemented in the proposed design. The performance of the MEMS gyroscope design is verified through a detailed coupled-field electric-structural-thermal finite element method (FEM)-based analysis

Challenging The Accuracy of a Single-test Lactate Threshold Protocol in Collegiate Rowers

Elite rowers use lactate threshold (LT) estimates as a basis for training intensity in order to achieve the greatest training volume. For convenience, LT is usually determined in a maximal LT/VO2max test. This simultaneous test is problematic because it requires a large power increment, which may not give the most accurate LT. PURPOSE: To challenge the validity of a simultaneous LT/VO2max test to estimate LT in rowers. METHODS: Collegiate rowers (n=20, 16F and 4M, age 19.3±1.3 years, height 171.5±7.1 cm, weight 70±14 kg, VO2max 44.6±5.5 ml•kg-1•min-1) performed two LT tests. Participants completed an incremental VO2max test with 3-minute intervals increasing by 30W and 40W for women and men respectively. The second test consisted of five 6-minute stages of 10W increments starting from 20W below the estimated LT. For both tests, blood lactate was measured at the end of each stage and LT was determined by the lactate deflection point. The difference in intensity between the first deflection point and the LT was then calculated. RESULTS: Average difference between LT1 and LT2 was 1.15 ± 13.4W, and were not statistically different (p=0.204). Average absolute difference was 9.95 ± 8.80W, and was different from the average (p=0.022). CONCLUSION: A second incremental test should be performed for the most precise determination of LT. This is particularly important to rowers who rely on LT to determine training intensities

A method to quantitatively evaluate Hamaker constant using the jump-into-contact effect in Atomic Force microscopy

We find that the jump-into-contact of the cantilever in the atomic force microscope (AFM) is caused by an inherent instability in the motion of the AFM cantilever. The analysis is based on a simple model of the cantilever moving in a nonlinear force field. We show that the jump-into-contact distance can be used to find the interaction of the cantilever tip with the surface. In the specific context of the attractive van der Waals interaction, this method can be realized as a new method of measuring the Hamaker constant for materials. The Hamaker constant is determined from the deflection of the cantilever at the jump-into-contact using the force constant of the cantilever and the tip radius of curvature, all of which can be obtained by measurements. The results have been verified experimentally on a sample of cleaved mica, a sample of Si wafer with natural oxide and a silver film, using a number of cantilevers with different spring constants. We emphasize that the method described here is applicable only to surfaces that have van der Waals interaction as the tip-sample interaction. We also find that the tip to sample separation at the jump-into-contact is simply related to the cantilever deflection at this point, and this provides a method to exactly locate the surface.Comment: 11 pages, 4 figures, 1 tabl

Asset, Capital Structure, Liquidity, Firm Size’s Impact on Stock Return

oai:ojs.ijcf.ticaret.edu.tr:article/197The aim of this study is to analyze the effect of  Asset and Capital Structure, Liquidity and  Firm Size on Stock Return of companies grouped as LQ-45 index listed in Indonesia Stock Exchange (IDX) during 2015 up to 2019 period. The research involves the secondary data in the form of financial annual report collected from IDX website,  sample used is purposive sampling and research object is Asset and Capital Structure, Liquidity and Firm Size as independent variables and Stock Return as dependent variable while analyzing used SPSS 2.0,  E-views 9.0 version. The result shown that when Stork Return measured by market price, Firm Size affects significantly on Stock Return, meanwhile Asset Structure, Capital Structure, Liquidity does not and Firm Size does not moderate the relation between Asset Structure, Capital Structure, Liquidity and Stock Return. But when Stock Return measured by Return on Equity (ROE) it is found that Capital Structure, Liquidity and Firm Size affect Return on Equity, meanwhile Asset Structure and Firm Size also moderates the relation between Asset Structure, Capital Structure, Liquidity and ROE. This finding implies that firm management must pay attention on market measurement performance in their strategy to achieve company goals. The originality of this study is that about the period as the last 5 years and the research object of companies grouped as LQ-45 index and measurement comparation between book value and market value of stock return.  

Signals of non-extensive statistical mechanics in high-energy nuclear collisions

Starting from the presence of non-ideal plasma effects due to strong coupled plasma in the early stage of relativistic heavy-ion collisions, we investigate, from a phenomenological point of view, the relevance of non-conventional statistical mechanics effects on the rapidity spectra of net proton yield at AGS, SPS and RHIC. We show that the broad rapidity shape measured at RHIC can be very well reproduced in the framework of a non-linear relativistic Fokker-Planck equation which incorporates non-extensive statistics and anomalous diffusion

Stochastic Resonance: influence of a f−κf^{-\kappa} noise spectrum

Here, in order to study \textit{stochastic resonance} (SR) in a double-well potential when the noise source has a spectral density of the form $f^{-\kappa}$ with varying $\kappa$, we have extended a procedure, introduced by Kaulakys et al (Phys. Rev. E \textbf{70}, 020101 (2004)). In order to have an analytical understanding of the results, we have obtained an effective Markovian approximation, that allows us to make a systematic study of the effect of such kind of noises on the SR phenomenon. The comparison of numerical and analytical results shows an excellent qualitative agreement indicating that the effective Markovian approximation is able to correctly describe the general trends.Comment: 11 pages, 6 figures, submitted to Euro.Phys.J.