6,911 research outputs found
The Impact of Crowdfunding Financial Attributes On Entrepreneurship Risk Taking
This paper aims to study the impact of Crowdfunding financial attributes on entrepreneurship risk taking. This study was applied on Arabic Crowdfunding platforms from all crowdfunding models.
The population of the study consists of individuals, entrepreneurs, investors, employees at electronic-crowd funding Arabic platforms. According to last statics at (2018), there are (12) legit Arabic platforms working in this field. Several statistical tools were used for data analysis and hypotheses testing, including reliability Correlation using Cronbach’s alpha, “ANOVA”, Simple Linear Regression. The overall findings of the current paper show that there is a significant statistical impact for financial properties on entrepreneurship and this effect around (25%). Furthermore, the current paper is unique by topic and population as it is the first study on Arabic crowdfunding platforms
Analysis of Critical State Response in Thin Films by ac Susceptibility Measurements
Harmonic analysis of the temperature dependence of the nonlinear ac
susceptibility of Nb thin film gives excellent agreement with the
susceptibility calculated on basis of model of the hysteretic critical state in
2D disk.Comment: 4 pages, 4 figures, MT20 conference, accepted for IEEE Trans. Appl.
Supercon
Semi-classical behavior of P\"oschl-Teller coherent states
We present a construction of semi-classical states for P\"oschl-Teller
potentials based on a supersymmetric quantum mechanics approach. The parameters
of these "coherent" states are points in the classical phase space of these
systems. They minimize a special uncertainty relation. Like standard coherent
states they resolve the identity with a uniform measure. They permit to
establish the correspondence (quantization) between classical and quantum
quantities. Finally, their time evolution is localized on the classical phase
space trajectory.Comment: 7 pages, 2 figures, 1 animatio
Criteria for accurate determination of the magnon relaxation length from the nonlocal spin Seebeck effect
The nonlocal transport of thermally generated magnons not only unveils the
underlying mechanism of the spin Seebeck effect, but also allows for the
extraction of the magnon relaxation length () in a magnetic
material, the average distance over which thermal magnons can propagate. In
this study, we experimentally explore in yttrium iron garnet (YIG)/platinum
systems much further ranges compared with previous investigations. We observe
that the nonlocal SSE signals at long distances () clearly deviate from a
typical exponential decay. Instead, they can be dominated by the nonlocal
generation of magnon accumulation as a result of the temperature gradient
present away from the heater, and decay geometrically as . We emphasize
the importance of looking only into the exponential regime (i.e., the
intermediate distance regime) to extract . With this principle, we
study as a function of temperature in two YIG films which are 2.7
and 50 m in thickness, respectively. We find to be around 15
m at room temperature and it increases to 40 m at 3.5 K. Finite
element modeling results agree with experimental studies qualitatively, showing
also a geometrical decay beyond the exponential regime. Based on both
experimental and modeling results we put forward a general guideline for
extracting from the nonlocal spin Seebeck effect.Comment: 9 pages, 7 figure
Frequency and power dependence of spin-current emission by spin pumping in a thin film YIG/Pt system
This paper presents the frequency dependence of the spin current emission in
a hybrid ferrimagnetic insulator/normal metal system. The system is based on a
ferrimagnetic insulating thin film of Yttrium Iron Garnet (YIG, 200 nm) grown
by liquid-phase-epitaxy (LPE) coupled with a normal metal with a strong
spin-orbit coupling (Pt, 15 nm). The YIG layer presents an isotropic behaviour
of the magnetization in the plane, a small linewidth, and a roughness lower
than 0.4 nm. Here we discuss how the voltage signal from the spin current
detector depends on the frequency [0.6 - 7 GHz], the microwave power, Pin, [1 -
70 mW], and the in-plane static magnetic field. A strong enhancement of the
spin current emission is observed at low frequencies, showing the appearance of
non-linear phenomena.Comment: 7 pages, 5 figure
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