Cybercrime Pervasiveness, Consequences, and Sustainable Counter Strategies

As our connectivity and dependency on technology increases, so does our vulnerability. Technology has provided not only new tools, but also new opportunities for criminals in the digital world. The abuse of new technologies has been threatening economic and Jinancial security and actually devastating the lives of affected indivicluals. In Nigeria, cybercrime has recorded mostly foregin-based individuals and organizations as victims thereby getting Nigeria ranked among the nations with notorious pemasiveness of high-tech crimes. Indeed, adequately formulating a strategy to contain the menace of cybercrime presents aformidable challenge to law enforcement. This paper x-rays noted instances of cybercrime pervasiveness, its devastating consequences, and up-to-date countermeasures in Nigeria It develops an enforceable/sustainable framework to determine how critical infrastructures are put at risk snd how law enforcement should react in responding to the threats

Calculation of accurate permanent dipole moments of the lowest 1,3Σ+^{1,3} \Sigma^+ states of heteronuclear alkali dimers using extended basis sets

The obtention of ultracold samples of dipolar molecules is a current challenge which requires an accurate knowledge of their electronic properties to guide the ongoing experiments. In this paper, we systematically investigate the ground state and the lowest triplet state of mixed alkali dimers (involving Li, Na, K, Rb, Cs) using a standard quantum chemistry approach based on pseudopotentials for atomic core representation, gaussian basis sets, and effective terms for core polarization effects. We emphasize on the convergence of the results for permanent dipole moments regarding the size of the gaussian basis set, and we discuss their predicted accuracy by comparing to other theoretical calculations or available experimental values. We also revisit the difficulty to compare computed potential curves among published papers, due to the differences in the modelization of core-core interaction.Comment: accepted to J. Chem. Phy

Tensile and fatigue properties of Inconel 718 at cryogenic temperatures

Tests to determine the tensile and fatigue properties of Inconel 718 at cryogenic temperatures show that the alloy increases in strength at low temperatures, with very little change in toughness. The effect of surface finish and grain size on the fatigue properties was also determined

Integrable random matrix ensembles

We propose new classes of random matrix ensembles whose statistical properties are intermediate between statistics of Wigner-Dyson random matrices and Poisson statistics. The construction is based on integrable N-body classical systems with a random distribution of momenta and coordinates of the particles. The Lax matrices of these systems yield random matrix ensembles whose joint distribution of eigenvalues can be calculated analytically thanks to integrability of the underlying system. Formulas for spacing distributions and level compressibility are obtained for various instances of such ensembles.Comment: 32 pages, 8 figure

Periodic orbits contribution to the 2-point correlation form factor for pseudo-integrable systems

The 2-point correlation form factor, $K_2(\tau)$, for small values of $\tau$ is computed analytically for typical examples of pseudo-integrable systems. This is done by explicit calculation of periodic orbit contributions in the diagonal approximation. The following cases are considered: (i) plane billiards in the form of right triangles with one angle $\pi/n$ and (ii) rectangular billiards with the Aharonov-Bohm flux line. In the first model, using the properties of the Veech structure, it is shown that $K_2(0)=(n+\epsilon(n))/(3(n-2))$ where $\epsilon(n)=0$ for odd $n$, $\epsilon(n)=2$ for even $n$ not divisible by 3, and $\epsilon(n)=6$ for even $n$ divisible by 3. For completeness we also recall informally the main features of the Veech construction. In the second model the answer depends on arithmetical properties of ratios of flux line coordinates to the corresponding sides of the rectangle. When these ratios are non-commensurable irrational numbers, $K_2(0)=1-3\bar{\alpha}+4\bar{\alpha}^2$ where $\bar{\alpha}$ is the fractional part of the flux through the rectangle when $0\le \bar{\alpha}\le 1/2$ and it is symmetric with respect to the line $\bar{\alpha}=1/2$ when $1/2 \le \bar{\alpha}\le 1$. The comparison of these results with numerical calculations of the form factor is discussed in detail. The above values of $K_2(0)$ differ from all known examples of spectral statistics, thus confirming analytically the peculiarities of statistical properties of the energy levels in pseudo-integrable systems.Comment: 61 pages, 13 figures. Submitted to Communications in Mathematical Physics, 200

V745\,Cassiopeia: an interacting young massive binary in a multiple star system

We present spectroscopic observations of the massive early type system V745\,Cas, embedded in a multiple star system. The brightest star of the system is the eclipsing binary V745\,Cas with an orbital period of 1.41 days. The radial velocities of both components and light curves obtained by $INTEGRAL$ and $Hipparcos$ missions were analysed. The components of V745\,Cas are shown to be a B0\,V primary with a mass M$_p$=18.31$\pm$0.51 M$_{\odot}$ and radius R$_p$=6.94$\pm$0.07 R$_{\odot}$ and a B(1-2)\,V secondary with a mass M$_s$=10.47$\pm$0.28 M$_{\odot}$ and radius R$_s$=5.35$\pm$0.05 R$_{\odot}$. Our analysis shows that both components fill their corresponding $Roche$ lobes, indicating double contact configuration. Using the UBVJHK magnitudes and interstellar absorption we estimated the mean distance to the system as 1700$\pm$50\,pc. The locations of the component stars in the mass-luminosity, mass-radius, effective temperature-mass and surface gravity-mass are in agreement with those of the main-sequence massive stars. We also obtained $UBV$ photometry of the three visual companions and we estimate that all are B-type stars based upon their de-reddened colours.We suspect that this multiple system is probably a member of the Cas OB4 association in the $Perseus$ arm of the $Galaxy$.Comment: 21 pages, 7 figures Accepted by MNRA