A Contribution to the Scanning Electron Microscope Based Microcharacterization of Semi-Insulating Gallium Arsenide Substrates

The macroscopic behaviour of semiconducting materials is determined by the distribution of microscopic defects like dislocations, impurities and intrinsic defects. Therefore, microanalytical methods are necessary to control the influence of technological process parameters on the materials properties. In the case of GaAs substrates, measurements of the cathodoluminescence (CL) and the electron beam induced voltage (EBIV) as well as the new charging technique seem to be promising methods to perform this task. CL-micrographs of as-grown GaAs substrates show bright cellular structures, which correspond to dislocation networks. Comparative investigations by use of the new charging contrast technique indicate an increased conductivity in the bright areas. CL-measurements of annealed substrates reveal additional characteristic island-like structures in the cell interior. Both, cellular and island-like structures can also be visualized by the EBIV technique. These results can be explained by a homogeneous conductivity and an inhomogeneous distribution of the excess carrier lifetime

American palm ethnomedicine: A meta-analysis

<p>Abstract</p> <p>Background</p> <p>Many recent papers have documented the phytochemical and pharmacological bases for the use of palms (<it>Arecaceae</it>) in ethnomedicine. Early publications were based almost entirely on interviews that solicited local knowledge. More recently, ethnobotanically guided searches for new medicinal plants have proven more successful than random sampling for identifying plants that contain biodynamic ingredients. However, limited laboratory time and the high cost of clinical trials make it difficult to test all potential medicinal plants in the search for new drug candidates. The purpose of this study was to summarize and analyze previous studies on the medicinal uses of American palms in order to narrow down the search for new palm-derived medicines.</p> <p>Methods</p> <p>Relevant literature was surveyed and data was extracted and organized into medicinal use categories. We focused on more recent literature than that considered in a review published 25 years ago. We included phytochemical and pharmacological research that explored the importance of American palms in ethnomedicine.</p> <p>Results</p> <p>Of 730 species of American palms, we found evidence that 106 species had known medicinal uses, ranging from treatments for diabetes and leishmaniasis to prostatic hyperplasia. Thus, the number of American palm species with known uses had increased from 48 to 106 over the last quarter of a century. Furthermore, the pharmacological bases for many of the effects are now understood.</p> <p>Conclusions</p> <p>Palms are important in American ethnomedicine. Some, like <it>Serenoa repens </it>and <it>Roystonea regia</it>, are the sources of drugs that have been approved for medicinal uses. In contrast, recent ethnopharmacological studies suggested that many of the reported uses of several other palms do not appear to have a strong physiological basis. This study has provided a useful assessment of the ethnobotanical and pharmacological data available on palms.</p

Tailoring PBAT/PLA/Babassu films for suitability of agriculture mulch application

Babassu was studied as a vegetable filler in a blend consisting of polybutyrateadipate terephthalate and polylactic acid aiming at preparation of bio-based and biodegradable films by solvent casting. The morphology, thermal, and mechanical properties were investigated with optical, thermoanalytical, and spectroscopic methods and correlated with the sample setup. Although only laboratory scale for film production has been applied in this work, the results suggest that the composite PBAT/PLA with 10%Babassu may be a suitable material for the application as agricultural mulch films. Such Babassu-based films would be environmentally friendly and cost-effective at the same time

Tailoring PBAT/PLA/Babassu films for suitability of agriculture mulch application

<p>Babassu was studied as a vegetable filler in a blend consisting of polybutyrate adipate terephthalate and polylactic acid aiming at preparation of bio-based and biodegradable films by solvent casting. The morphology, thermal, and mechanical properties were investigated with optical, thermoanalytical, and spectroscopic methods and correlated with the sample setup. Although only laboratory scale for film production has been applied in this work, the results suggest that the composite PBAT/PLA with 10% Babassu may be a suitable material for the application as agricultural mulch films. Such Babassu-based films would be environmentally friendly and cost-effective at the same time.</p