Magnetic field mapper

Magnetic field mapper locates imperfections in cadmium sulphide solar cells by detecting and displaying the variations of the normal component of the magnetic field resulting from current density variations. It can also inspect for nonuniformities in other electrically conductive materials

Coreless and singular vortex lattices in rotating spinor Bose-Einstein condensates

We theoretically investigate vortex-lattice phases of rotating spinor Bose-Einstein condensates (BEC) with the ferromagnetic spin-interaction by numerically solving the Gross-Pitaevskii equation. The spinor BEC under slow rotation can sustain a rich variety of exotic vortices due to the multi-component order parameters, such as the Mermin-Ho and Anderson-Toulouse coreless vortices (the 2-dimensional skyrmion and meron) and the non-axisymmetric vortices with the sifting vortex cores. Here, we present the spin texture of various vortex-lattice states at higher rotation rates and in the presence of the external magnetic field. In addition, the vortex phase diagram is constructed in the plane by the total magnetization $M$ and the external rotation frequency $\Omega$ by comparing the free energies of possible vortices. It is shown that the vortex phase diagram in a $M$-$\Omega$ plane may be divided into two categories; (i) the coreless vortex lattice formed by the several types of Mermin-Ho vortices and (ii) the vortex lattice filling in the cores with the pure polar (antiferromagnetic) state. In particular, it is found that the type-(ii) state forms the composite lattices of coreless and polar-core vortices. The difference between the type-(i) and type-(ii) results from the existence of the singularity of the spin textures, which may be experimentally confirmed by the spin imaging within polarized light recently proposed by Carusotto and Mueller. We also discussed on the stability of triangular and square lattice states for rapidly rotating condensates.Comment: to be published in Phys. Rev.

How the Carbon to Nitrogen Ration Affects Soil Microorganisms

This slide presentation for the Natural Sciences Poster Session at Parkland College presents information on the importance of the correct ratio between nitrogen and carbon for microorganism health

An Algorithm for the Electromagnetic Scattering Due to an Axially Symmetric Body with an Impedance Boundary Condition

Let B be a body in R3, and let S denote the boundary of B. The surface S is described by S = {(x, y, z): (x2 + Y2)½= ƒ(z), -1≤ z ≤ I}, where ƒ analytic function that is real and positive on (-1, 1) and ƒ(±1) = 0. An algorithm is described for computing the scattered field due to a plane wave incident field, under Leontovich boundary conditions. The Galerkin method of solution used here leads to a block diagonal matrix involving 2M + 1 blocks, each block being of order 2(2N + 1). If, e.g., N = O(M2), the computed scattered field is accurate to within an error bounded by Ce-cN1 2 depending only on ƒ

An Algorithm for the Electromagnetic Scattering Due to an Axially Symmetric Body with an Impedance Boundary Condition

Let B be a body in R3, and let S denote the boundary of B. The surface S is described by S = {(x, y, z): (x2 + Y2)½= ƒ(z), -1≤ z ≤ I}, where ƒ analytic function that is real and positive on (-1, 1) and ƒ(±1) = 0. An algorithm is described for computing the scattered field due to a plane wave incident field, under Leontovich boundary conditions. The Galerkin method of solution used here leads to a block diagonal matrix involving 2M + 1 blocks, each block being of order 2(2N + 1). If, e.g., N = O(M2), the computed scattered field is accurate to within an error bounded by Ce-cN1 2 depending only on ƒ

Apollo to Artemis: Mining 50-Year Old Records to Inform Future Human Lunar Landing Systems

Under the Artemis lunar exploration program, NASA is committed to landing American astronauts on the moon by 2024. While NASAs new Space Launch System rocket and Orion capsule will carry astronauts from Earth to the Gateway, the human lunar landing system has not yet been fully defined. As in the Apollo program, there are concerns for vehicle weight and internal volume such that seats may not be desirable, and standing during lunar descent and ascent may be a preferred engineering solution. With such a design, astronauts will experience +GZ (head-to-foot) accelerations during capsule accelerations, and it is unclear whether spaceflight deconditioned astronauts can tolerate these. Apollo astronauts stood during lunar descent and ascent, and the data contained in the early program records for those missions represent a unique resource that may provide insights to the cardiovascular stress associated with this human landing system design

Bose-Einstein condensation at constant temperature

We present a novel experimental approach to Bose-Einstein condensation by increasing the particle number of the system at almost constant temperature. In particular the emergence of a new condensate is observed in multi-component F=1 spinor condensates of 87-Rb. Furthermore we develop a simple rate-equation model for multi-component BEC thermodynamics at finite temperature which well reproduces the measured effects.Comment: 4 pages, 3 figures, RevTe