Numerical Simulation of Losses in Four-Way Pipe Junctions

To design pipelines, engineers need to know how much energy the fluid in the pipe has at different locations in the pipe network. The energy the fluid has comes in the form of pressure, velocity, and elevation. As fluid travels through a pipe, it loses energy for many different reasons. Some of those reasons include friction between the fluid and the pipe wall, shear forces within the fluid, changes in flow direction, changes in elevation, or various pipe fittings like elbows, tee’s, valves, reducers, and expanders. Many of the causes of energy loss are well researched. One cause of energy loss that is not well documented is the energy loss experienced through four-way junctions in pipe networks or crosses. These junctions make the fluid lose energy differently through each of the junction’s legs due to differences in flow between the legs and different changes in direction between different legs. For this paper, computer simulations were set up to determine the energy loss factor for each leg of a cross junction for various scenarios

Erste Untersuchungen zur Weidemast männlicher Milchviehkälber

Im Ökologischen Landbau werden die meisten der männlichen Kälber aus der Milchproduktion konventionell gemästet. Wir haben das Leistungsvermögen von männlichen Kälbern der Rasse Deutsche Holstein unter Weidebedingungen als Möglichkeit einer ökologischen Kalbfleischerzeugung untersucht

On the Efimov effect in systems of one- or two-dimensional particles

We study virtual levels of $N$-particle Schr\"odinger operators and prove that if the particles are one-dimensional and $N\ge 3$, then virtual levels at the bottom of the essential spectrum correspond to eigenvalues. The same is true for two-dimensional particles if $N\ge 4$. These results are applied to prove the non-existence of the Efimov effect in systems of $N\ge 4$ one-dimensional or $N\ge 5$ two-dimensional particles.Comment: 49 page

The absence of the Efimov effect in systems of one- and two-dimensional particles

We study virtual levels of $N$-particle Schrödinger operators and prove that if the particles are one-dimensional and $N\ge3$, then virtual levels at the bottom of the essential spectrum correspond to eigenvalues. The same is true for two-dimensional particles if $N\ge4$. These results are applied to prove the non-existence of the Efimov effect in systems of $N\ge4$ one-dimensional or $N\ge5$ two-dimensional particles

Decay properties of zero-energy resonances of multi-particle Schrödinger operators and why the Efimov effect does not exist for systems of N≥4N\ge4 particles

We consider $N$-body Schrödinger operators with a virtual level at the threshold of the essential spectrum. We show that in the case of $N\ge3$ particles in dimension $n\ge3$ virtual levels correspond to eigenvalues of the system and we obtain decay rates of the corresponding eigenfunctions in dependence on the dimension and the number of particles. We prove that in dimension $n\ge3$ the Hamiltonian of $N\ge4$ particles interacting via short-range potentials admits only a finite number of negative eigenvalues. We extend our results to dimension $n=1$ and $n=2$ in case of $N\ge4$ fermions

Using forced alignment for sociophonetic research on a minority language

Until recently, large-scale phonetic analyses have been out of reach for under-documented languages, but with the advent of methodologies such as forced alignment, they have now become possible. This paper describes a methodology for applying forced alignment (using the Montreal Forced Aligner) to a speech corpus of Matukar Panau, a minority language spoken in Papua New Guinea. We obtained measurements for 68,785 vowel tokens, produced in both narrative and conversational data by 34 speakers. We examined the social conditioning on a subset of these vowels according to traditional sociolinguistic categories of age and gender, and also consider the impact of clan as a major axis of organization in this community. We show that there is a role for clan as a sociolinguistic factor in conditioning the variation observed