A Consistent BGK Model with Velocity-Dependent Collision Frequency for Gas Mixtures.

We derive a multi-species BGK model with velocity-dependent collision frequency for a non-reactive, multi-component gas mixture. The model is derived by minimizing a weighted entropy under the constraint that the number of particles of each species, total momentum, and total energy are conserved. We prove that this minimization problem admits a unique solution for very general collision frequencies.

Impact of Daily Grazing Time on Dairy Cow Welfare-Results of the Welfare Quality Protocol.

Grazing provides livestock better opportunities to act out their species-specific behavior compared to restrictive stable conditions. The aim of the present study was to examine the effects of daily grazing time on welfare of dairy cows in organic and conventional farms based on the Welfare Quality assessment protocol for dairy cattle (WQ). Therefore, we applied the WQ on 32 dairy farms (classified in 3 groups: Group 0, minor/zero grazing, n = 14; Group 1, medium grazing, n = 10; Group 2, high grazing, n = 8).

Communication: A simple full range analytical potential for H2b(3)∑u (+), H-He (2)∑(+), and He2 (1)∑g (.).

The Tang-Toennies potential for the weakly interacting systems H2b(3)Σu (+), H-He (2)Σ(+), and He2 (1)Σg (+) is extended down to the united atom limit of vanishing internuclear distance. A simple analytic expression connects the united atom limiting potential with the Tang-Toennies potential in the well region. The new potential model is compared with the most recent ab initio calculations for all three systems.

Fluorescence spectroscopy in process analytical technology (PAT): simultaneous quantification of two active pharmaceutical ingredients in a tablet formulation.

Many pharmaceuticals include highly potent active pharmaceutical ingredients (API), which only require a small dosage to obtain the desired therapeutic effect. This leads to a challenge for quantification of the API using process analytical technology, since the standard nondestructive measurement technique, near-infrared spectroscopy, is not able to quantify below 1% (weight/weight (w/w)) API content. In formulations with more than one API, this challenge is further increased.

Measurement of active content in escitalopram tablets by a near-infrared transmission spectroscopy model that encompasses batch variability.

Near-infrared transmission (NIT) spectroscopy, with high-performance liquid chromatography as reference method, was used to study the variation of the active pharmaceutical ingredient (API), escitalopram, in five tablet batches (4%-12%, w/w) manufactured by direct compression. This study investigates the influence of sample orientation, powder segregation, and compression force on the NIT spectra. For this purpose, tablet samples were taken at six different production time points, at three different compression forces, and presented to the spectrometer in four different orientations and in three spectroscopic replicates.