v. dannon showed that spherical curves in e4 can be given by frenet-like equations, and he thengave an integral characterization for spherical curves in e4 . in this paper, lorentzian spherical timelike andspacelike curves in the space time 41 r are shown to be given by frenet-like equations of timelike andspacelike curves in the euclidean space e3 and the minkowski 3-space 31 r . thus, finding...

the effect of mentha spicata l. extract on the corrosion behaviour of carbon steel in 1.0 m hcl solution was investigated using polarization, electrochemical impedance spectroscopy (eis) and electrochemical noise (en) techniques. the solution containing 250 ppm of the ethanolic solution of extract showed the highest inhibition efficiency (ie). the effect of temperature on the rate of corrosion ...

aisi 304l austenitic stainless steel with different grain sizes of 0.5 -12 μm was obtained through the martensiticprocess. corrosion behavior of different samples was investigated in a 0.5m hcl solution using open circuitpotential, potentiodynamic polarization and electrochemical impedance spectroscopy tests. also, the correlationbetween the grain size and pitting corrosion resistance was asses...

The corrosion inhibition effect of 3-amino-5-mercapto-1,2,4-triazole (AMT) on AA2024 aluminium alloy in 3.5 wt.% NaCl solution was investigated, and the mechanism revealed. influence AMT concentration performance evaluated by potentiodynamic polarization curve electrochemical impedance spectroscopy (EIS). Surface analysis surface-enhanced Raman scattering (SERS) spectra were used to study adsor...

We explore the potential of pulsar timing arrays (PTAs) such as NANOGrav, EPTA, and PPTA to detect stochastic gravitational wave background in theories massive gravity. In general relativity, function describing dependence correlation between arrival times signals from two pulsars on angle them is known Hellings-Downs curve. compute analogous overlap reduction for gravity, including additional ...

An automatic inverse method has been developed for generating layered earth models from electrical sounding data. The models have the minimum number of layers required to fit a resistivity sounding curve or a combined resistivity and induced polarization sounding. The ground is modeled using a very large number of thin layers to accommodate arbitrary variations. The properties of the layers are...

Compensation of Polarization Mode Dispersion (PMD) induced by a chirped Bragg grating is performed using a short length of highly birefringent fiber. A recirculating loop experiment demonstrates complete PMD compensation of the chirped Bragg grating. This simple method can be extended to deterministic PMD compensation of any components. Introduction: Pulse broadening induced by PMD is now an im...

Aims. We present the first results of a polarimetric survey of main-belt asteroids at Complejo Astronómico El Leoncito (Casleo), San Juan, Argentina. The aims of this survey are to increase the database of asteroid polarimetry, to estimate diversity in polarimetric properties of asteroids that belong to different taxonomic classes, and to search for objects that exhibit anomalous polarimetric p...