Pulsed laser deposition growth of Fe3O4 on III–V semiconductors for spin injection

We report on the growth of thin layers of Fe3O4 on GaAs and InAs by pulsed laser deposition. It is found that Fe3O4 grows epitaxially on InAs at a temperature of 350 °C. X-ray photoelecton spectroscopy (XPS) studies of the interface show little if any interface reaction resulting in a clean epitaxial interface. In contrast, Fe3O4 grows in columnar fashion on GaAs, oriented with respect to the growth direction but with random orientation in the plane of the substrate. In this case XPS analysis showed much more evidence of interface reactions, which may contribute to the random-in-plane growth

The most massive galaxies in clusters are already fully grown at z∼0.5z \sim 0.5

By constructing scaling relations for galaxies in the massive cluster MACSJ0717.5 at $z=0.545$ and comparing with those of Coma, we model the luminosity evolution of the stellar populations and the structural evolution of the galaxies. We calculate magnitudes, surface brightnesses and effective radii using HST/ACS images and velocity dispersions using Gemini/GMOS spectra, and present a catalogue of our measurements for 17 galaxies. We also generate photometric catalogues for $\sim 3000$ galaxies from the HST imaging. With these, we construct the colour-magnitude relation, the fundamental plane, the mass-to-light versus mass relation, the mass-size relation and the mass-velocity dispersion relation for both clusters. We present a new, coherent way of modelling these scaling relations simultaneously using a simple physical model in order to infer the evolution in luminosity, size and velocity dispersion as a function of redshift, and show that the data can be fully accounted for with this model. We find that (a) the evolution in size and velocity dispersion undergone by these galaxies between $z \sim 0.5$ and $z \sim 0$ is mild, with $R_e(z) \sim (1+z)^{-0.40\pm0.32}$ and $\sigma(z) \sim (1+z)^{0.09 \pm 0.27}$, and (b) the stellar populations are old, $\sim 10$ Gyr, with a $\sim 3$ Gyr dispersion in age, and are consistent with evolving purely passively since $z \sim 0.5$ with $\Delta \log M/L_B = -0.55_{-0.07}^{+0.15} z$. The implication is that these galaxies formed their stars early and subsequently grew dissipationlessly so as to have their mass already in place by $z \sim 0.5$, and suggests a dominant role for dry mergers, which may have accelerated the growth in these high-density cluster environments.Comment: 20 pages; accepted for publication in MNRA

\u3cem\u3eMr. Goat\u27s Valentine\u3c/em\u3e by Eve Bunting

https://digitalcommons.cedarville.edu/intern_book_reviews/1189/thumbnail.jp

\u3cem\u3e Samira and the Skeletons\u3c/em\u3e by Camilla Kuhn

https://digitalcommons.cedarville.edu/intern_book_reviews/1191/thumbnail.jp

A Four-Legged Megalosaurus and Swimming Brontosaurs

Thomas Kuhn in his famous work The Structure of Scientific Revolutions laid out the framework for his theory of how science changes. At the advent of dinosaur paleontology fossil hunters like Gideon Mantell discovered some of the first dinosaurs like Iguanodon and Megalosaurus. Through new disciples like Georges Cuvier’s comparative anatomy lead early dinosaur paleontologist to reconstruct them like giant reptiles of absurd proportions. This lead to the formation of a new paradigm that prehistoric animals like dinosaurs existed and eventually went extinct. The first reconstructions of dinosaur made them to look like giant counterparts of their modern cousins. Then in 1841, Richard Owen coined the term dinosaur, and put the newly discovered dinosaurs into a special group based on similar morphological characteristics. He reconstructed them to look like giant elephant like reptiles. They were slow, sluggish, and their tales dragged the ground. Then in 1858, William Foulke and Joseph Leidy discovered the dinosaur Hadrosaurus which had morphological characteristics that hindered the animal from being quadrupedal. As a result a new paradigm was formed and some dinosaurs were lifted off the ground. They were reconstructed to look like giant reptilian kangaroos in stance, but they were still considered slow, sluggish, with tails still dragging behind them. This paradigm persisted until the 1960’s when paleontologist John Ostrom realized that there was an anomaly within dinosaur paleontology. The environments that dinosaurs inhabited did not match with the reconstructions of swamp dwelling animals, and dinosaur anatomy also did not match those reconstructions. Ostrom’s discovery and description of Deinonychus with its very bird like skeleton lead him to conclude that dinosaurs were energetic, and probably endothermic. This resulted in a crisis which lead other paleontologist to research this anomaly. More discoveries proved Ostrom’s new paradigm and dinosaur paleontology underwent a scientific revolution from the 1960’s to the 1980’s. Formally termed the dinosaur renaissance this revolution lead to dinosaurs being reconstructed as active, intelligent animals no longer with their tails dragging behind them

Needs of terminally ill cancer patients in an in-patient hospice unit

In Western Australia, in-patient hospice/palliative care units are caring for increasing numbers of terminally ill cancer patients. Hospice philosophy is based on the belief that the terminally ill patient in individual needs are of paramount importance. The needs of advanced cancer patients have been researched in the home, for patients continuing or having completed curative treatment, and for patients receiving palliative care. However, there is a lack of literature about the needs of terminally ill cancer patients in in-patient hospices. Using a descriptive approach, this study investigated the needs of six terminally ill cancer patients in a 26 bed in-patient hospice unit. Semi-structured interviews based on Henderson\u27s (1964) 14 fundamental needs were used to elicit information about these patients needs’. Data was analysed using thematic analysis to determine common categories of need. Findings suggest that terminally ill cancer patients in an in-patient hospice unit have seven common need categories. These are physiological, psychological, sociological, spiritual, informational, financial and environmental categories of need. Three overriding needs are described as the need to feel safe, to maintain family contact and to reduce the impact of visitors. Implications of the findings for nurses are discussed

Using CT Scans to Describe an Allosaurus Skull (Dinosauria: Theropoda)

In 2001, an Allosaurus skull (CMP 279) was discovered in the Skull Creek Basin in Moffat County, Colorado. The skull is one of the most complete for the species and even contains the hyoid bones, which are usually not present. The skull is now permanently mounted, for display purposes, thus making the study of the individual bones difficult for producing a paleo-anatomical description. Computed Tomography (CT) scans of CMP 279 were created in 2017 and then made available for this study in 2019. CT scans are being used to investigate internal anatomy of skulls such as the endocranial cavity, sinuses, or foramina for nerve endings. This approach to using CT scans for skull analyses is becoming popular and, when combined with observations from the actual specimen, a comprehensive description can be derived. The program used for this study was myVGL Viewer. The program allows scans to be viewed in the frontal (anterior-posterior), median (medial-lateral) and transverse (dorsal-ventral) planes at the same time, and a 3-D rendering of the skull. The scans indicate exact known placement of sutures. For example, the mandibular sutures can be difficult to determine by physical examination of the specimen, but through the use of the scans they can be clearly identified. The scans also give access to bones that are unreachable because of the display-mounting of the actual skull, an example being the palatine complex. Additionally, internal anatomy like the endocranial cavity from the scans reveal the lobes and cranial nerves within the brain. CT scans have provided a high-tech approach to doing detailed analysis of CMP 279 which, in turn, will facilitate a detailed description that is important in understanding the anatomy and diversity of Allosaurus genera

\u3cem\u3e When Spring Comes\u3c/em\u3e by Kevin Henkes illustrated by Laura Dronzek

https://digitalcommons.cedarville.edu/intern_book_reviews/1195/thumbnail.jp