An impurity of Ampicillin sodium formed during a gradient reverse phase high performance liquid chromatography (HPLC) analysis of stress stability samples of the drug substance Ampicillin sodium, and the level of this impurity was found at up to 0.9%. This impurity was identified by LC-MS and characterized by (1H NMR, LC/MS/MS, elemental analysis). Based on the spectral data, the impurity was n...

A magnetic impurity in a fermionic superfluid hosts bound quasiparticle states known as Yu-Shiba-Rusinov states. We argue here that, if the impurity is mobile (i.e., has a finite mass), the impurity and its bound Yu-Shiba-Rusinov quasiparticle move together as a midgap molecule, which has an unusual "Mexican-hat" dispersion that is tunable via the fermion density. We map out the impurity disper...

We investigate velocity statistics of an impurity immersed in a uniform granular fluid. We consider the cooling phase, and obtain scaling solutions of the inelastic Maxwell model analytically. First, we analyze identical fluid-fluid and fluid-impurity collision rates. We show that light impurities have similar velocity statistics as the fluid background, although their temperature is generally ...

Impurity profiling is a highly intelligent, tedious and expensive task in standardizing the drug products for marketing Authorization. This task usually more complex when the proper impurity standards are not available and synthesis of the same require extra ordinary high cost and time. It has been observed that many a time application for ANDA/DMF/CEP is delayed due to extra ordinary delay in ...

Impurity transport driven by electrostatic turbulence is analyzed in weaklycollisional tokamak plasmas using a semi-analytical model based on a boundary-layer solution of the gyrokinetic equation. Analytical expressions for the perturbed density responses are derived and used to determine the stability boundaries and the quasilinear particle fluxes. For moderate impurity charge number Z, the st...

Magnetic impurities coupled antiferromagnetically to a one-dimensional Heisenberg model are studied by numerical diagonalization of chains of finite clusters. By calculating the binding energy and the correlation function, it is shown that a local singlet develops around each impurity. This holds true for systems with a single impurity, with two impurities, and for impurities forming a lattice....

Embedding calculations that find approximate solutions to the Schrödinger equation for large molecules and realistic solids are performed commonly in a three step procedure involving (i) construction of a model system with effective interactions approximating the low energy physics of the initial realistic system, (ii) mapping the model system onto an impurity Hamiltonian, and (iii) solving the...

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We consider the problem of screening of an electrically charged impurity in a clean graphene sheet. When electron-electron interactions are neglected, the screening charge has a sign opposite to that of the impurity, and is localized near the impurity. Interactions between electrons smear out the induced charge density to give a largedistance tail that follows approximately, but not exactly, an...

We demonstrate analytically and numerically that the impurity mode plays a very important role in the kink scattering by a local inhomogeneity, and a sine-Gordon kink may be trapped by an impurity due to loss of its kinetic energy to excite the impurity mode. We develop a collective-coordinate approach to describe the kink—impurity interactions and calculate the threshold velocity ofkink captur...