Geometric and electronic structure of misfit layered compounds and epitaxial thin films of PbS on transition metal dichalcogenides

In the present thesis the geometric and electronic structures of the misfit layered compounds (PbS)$_{1.14}$NbS$_2$ and (PbS)$_{1.18}$TiS$_2$ have been investigated. The concept of growing misfit compounds by a chemical transport technique and by molecular beam epitaxy are explained. The crystals were characterized with respect to their stacking order, their lateral order, chemical purity and the properties of their cleavage plane. Misfit layered compounds exhibit outstanding properties that are connected to their unusual geometric structure: They consist of a highly ordered alternate stacking of two different subsystems. Due to the different symmetry of the subsystems a one-dimensional misfit is created along one in-plane layer axis. The influence of these geometric properties on the electronic structure was investigated by angle-resolved photoelectron spectroscopy with synchrotron radiation. The high stability and stacking order of misfit compounds could be attributed to a charge transfer as well as to covalent bonding. The one-dimensional misfit results in a change of the Fermi surface due to electron scattering by the quasiperiodic potential

Integrating hygiene improvement into HIV/AIDS programming to reduce diarrhea morbidity

This paper highlights discrete hygiene activities that organizations working in HIV/AIDS prevention and care can integrate into HIV/AIDS programs to help achieve the hygiene objectives outlined in the Preventive Care Package Guidance issued by the President’s Emergency Plan. These discrete hygiene activities can help mitigate the impact of diarrhea on people living with HIV and AIDS (PLWHA) and their families thereby prolonging and improving their quality of and protecting family members and caregivers from contracting diarrhea

3. Wochenbericht SO284

SONNE 284 Mooring Rescue Emden - Emden, 27.06. - 17.08.2021 3. WOCHENBERICHT 12.07. - 18.07.202

2. Wochenbericht SO284

SONNE 284 Mooring Rescue Emden - Emden, 27.06. - 17.08.2021 2. WOCHENBERICHT 05.07. - 11.07.202

1. Wochenbericht SO284

SONNE 284 Mooring Rescue Emden - Emden, 27.06. - 17.08.2021 1. WOCHENBERICHT 27.06. - 04.07.202

5. Wochenbericht SO284

SONNE 284 Mooring Rescue Emden - Emden, 27.06. - 17.08.2021 5. WOCHENBERICHT 26.07. - 01.08.202

4. Wochenbericht SO284

SONNE 284 Mooring Rescue Emden - Emden, 27.06. - 17.08.2021 4. WOCHENBERICHT 19.07. - 25.07.202

6. Wochenbericht SO284

SONNE 284 Mooring Rescue Emden - Emden, 27.06. - 17.08.2021 6. WOCHENBERICHT 02.08. - 08.08.202

On the classical central charge

In the canonical formulation of a classical field theory, symmetry properties are encoded in the Poisson bracket algebra, which may have a central term. Starting from this well understood canonical structure, we derive the related Lagrangian form of the central term.Comment: 23 pages, RevTeX, no figures; introduction improved, a few references adde