The analysis of the magnetic material abundance on the black sand of Nyanyi beach revealed magnetic material content, grain size, density, magnetic mineral content, and magnetic susceptibility value.The results of this study can be used for black sand development inTabanan district. The black sand magnetic material was determined by the extraction method. Mineral content was tested by using XRF equipment, and the magnetic properties of black sand were determined by using a Bartingtons MS2 Magnetic Susceptibility Meter and a Vibrating Sample Magnetometer. The data were analyzed descriptively quantitatively. The results show thatNyanyi beach sand physically has a characteristic dark gray color, tends to be black, and shiny with a weight fraction of magnetic material reaching 95.52%.The density of the magnetic material is 2072.6 with varying grain sizes of 53 600 .The average value of magnetic susceptibility is 27.212x 10-with Fe2O3magnetic mineral content of 86.68% and the element of Fe is 89.41%.The values of saturation magnetization, remanance magnetization, and coervicity reach37.74; 4.64; 103.93 Oe.

One of the characteristics of viruses is the stiffness of the virus shell. In the following review, the virus shell can be assumed to be a spring. The value of stiffness of the virus shell is different for various viruses depending on intrinsic properties (i.e. modulus of elasticity) and extrinsic properties (i.e. radius and thickness of the virus shell). In this paper, we analyze the value of stiffness of the virus shell by analytical dan simulation. The analytical method is based on plate and shell theory and Michell solution. The other, the simulation is based on finite element analysis (FEA) method. We examine the elasticity constants of two types of viruses, namely HIV-1 (mature) and HIV-1 (immature) viruses. It was found that the HIV-1 virus (mature) had a smaller elasticity constant than the elasticity constant of the HIV-1 virus (immature). This is closely related to the characteristics of the virus, i.e. size, thickness, and intrinsic properties of the virus. Viruses with smaller shell thickness have lower elasticity constants, so they are more efficient at infecting host cells than viruses with higher elasticity constants.

Virus is an infectious agent with microscopic size, a protective shell containing capsomere with protein material called a capsid, and the addition of a shell containing fat called a lipid coat. The one characteristic of a virus is about the shell stiffness, so the virus shell can be assumed as a spring. The value of stiffness of the virus shell is different for various viruses, depending on intrinsic properties (modulus of elasticity) and extrinsic properties (radius and thickness of the virus shell).In this paper, we analyze the value of stiffness of the virus shell by analytical and simulation. The analytical method is based on plate and shell theory and Michell solution. The other, the simulation is based on finite element analysis (FEA) method. For influenza lipid shell, we find that the stiffness value of the shell based on plate and shell theory is 0.0236 . Based on Michell solution, the stiffness value of the shell is 0.0225 . Also, the stiffness value of influenza lipid by FEA method is 0.0227 ± 0.0002 . Generally, based on the graph that the stiffness value of influenza lipid shell by analytical and simulation is approaching same.

We studied isometric stochastic flows of a Stratonovich stochastic differential equation on spheres, i.e., on the standard sphere S 7 s and Gromoll-Meyer exotic sphere Σ 7 GM . In this case, S 7 s and Σ 7 GM are homeomorphic but not diffeomorphic. The standard sphere S 7 s can be constructed as the quotient manifold Sp(2, H)/S 3 with the so-called •-action of S 3 , whereas the Gromoll-Meyer exotic sphere Σ 7 GM as the quotient manifold Sp(2, H)/S 3 with respect to the so-called -action of S 3 . The corresponding continuous-time stochastic process and its properties on the Gromoll-Meyer exotic sphere can be obtained by constructing a homeomorphism h : S 7 s → Σ 7 GM . The stochastic flow h * g s,t (ω) can be regarded as the same stochastic flow g s,t (ω) on S 7 , but viewed in Gromoll-Meyer differential structure. The flow g s,t (ω) on S 7s and the corresponding flow h * g s,t (ω) on Σ 7 GM constructed in this paper have the same regularities. There is no difference between the stochastic flow's appearance on S 7 viewed in standard differential structure and the appearance of the same stochastic flow viewed in the Gromoll-Meyer differential structure. Furthermore, since the inverse mapping h −1 is differentiable on Σ 7 GM , the Riemannian metric tensor [ f −1 ] * G on Σ 7 GM , i.e., the pull-back of the Riemannian metric tensor G on the standard sphere S s 7 , is also differentiable. This fact implies, for instance, the fact that the Fokker-Planck equation associated with the stochastic flow h * g s,t (ω) and the Fokker-Planck equation associated with the stochastic differential equation have the same regularities provided that the function β is C 1 -differentiable. Therefore both differential structures on S 7 give the same description of the dynamics of the distribution function of the stochastic process understudy on seven spheres.