A small sperm whale (Cetacea: Odontoceti, Physeteridae) from the Miocene of Antwerp

In the summer of 1967 during the construction of the circular highway in the city of Antwerp (Belgium) the fossil remains of a small physeterid whale were discovered. In the 1990’s the remains were sold by the collector and they disappeared from sight. In 2001 the fossils turned up again and were bought by the Museum of Natural History (Natuurhistorisch Museum de Peel) in Asten, the Netherlands, where they are now exhibited. This article presents (1) a re-examination of the site of discovery and its documentation by the collector, and (2) an investigation of the fossils that reappeared in 2001. Compared to the findings in situ, the fossils originating from glauconitic sands of late Early to Middle Miocene Age (Antwerpen Sands) are missing a number of teeth. The remaining pieces of the whale are described and illustrated in this study. On the basis of the teeth, some parts of the skull, the main parts of the atlas and the typically fused cervical vertebrae 2-7, as well as a photograph of the periotic it is concluded that the sperm whale belongs to the family Physeteridae, subfamily Physeterinae. Assigning to generic or specific rank turned out to be more difficult. Yet an attempt is made to interpret the sperm whale find in a provisional way by comparing its skull parts and teeth with physeterine genera and species described hitherto. Physeterula dubusii and Orycterocetus sp. seem to show closest affinities. Postcranial structure of fossil sperm whales is not very well known. The numerous fragments of the specimen described here could give a more complete insight in the overall skeletal structure of these Miocene odontocetes

An ellipsometer with variable angle of incidence for studies in ultrahigh vacuum

The windows for the vacuum chamber are incorporated into the optical bench system by means of flexible bellows which allow measurements to be made over a large range of angle of incidence, one of which is chosen so that maximum sensitivity is obtained. The principal angle of incidence was determined, and straightforward corrections for strain birefringence of vacuum chamber windows were made. Atomically clean surfaces of sodium chloride and lithium fluoride were investigated to verify the performance of the system. Submonolayer and monolayer coverage of water on these surfaces could be detected. On cleavage planes of NaCl, a first monolayer of adsorbed water is complete at about one torr only

Local‐Regional Similarity in Drylands Increases During Multiyear Wet and Dry Periods and in Response to Extreme Events

Climate change is predicted to impact ecosystems through altered precipitation (PPT) regimes. In the Chihuahuan Desert, multiyear wet and dry periods and extreme PPT pulses are the most influential climatic events for vegetation. Vegetation responses are most frequently studied locally, and regional responses are often unclear. We present an approach to quantify correlation of PPT and vegetation responses (as Normalized Difference Vegetation Index [NDVI]) at the Jornada ARS‐LTER site (JRN; 550 km2 area) and the surrounding dryland region (from 0 to 500 km distance; 400,000 km2 study area) as a way to understand regional similarity to locally observed patterns. We focused on fluctuating wet and dry years, multiyear wet or dry periods of 3–4 yr, and multiyear wet periods that contained one or more extreme high PPT pulses or extreme low rainfall. In all but extreme high PPT years, JRN PPT was highly correlated... (See article for full abstract)

Bends in the plane with variable curvature

Explicit formulae for planar variable curvature bends are constructed using Euler’s method of natural equations. The bend paths are expressed in terms of special functions. It is shown that the length of the different bend types varies linearly with increasing radius and that the curvature of variable curvature bends can be expressed as a multiple of the curvature of a circle

Unconventional carrier-mediated ferromagnetism above room temperature in ion-implanted (Ga, Mn)P:C

Ion implantation of Mn ions into hole-doped GaP has been used to induce ferromagnetic behavior above room temperature for optimized Mn concentrations near 3 at.%. The magnetism is suppressed when the Mn dose is increased or decreased away from the 3 at.% value, or when n-type GaP substrates are used. At low temperatures the saturated moment is on the order of one Bohr magneton, and the spin wave stiffness inferred from the Bloch-law T^3/2 dependence of the magnetization provides an estimate Tc = 385K of the Curie temperature that exceeds the experimental value, Tc = 270K. The presence of ferromagnetic clusters and hysteresis to temperatures of at least 330K is attributed to disorder and proximity to a metal-insulating transition.Comment: 4 pages, 4 figures (RevTex4

ОПРЕДЕЛЕНИЕ ПРОПУСКНОЙ СПОСОБНОСТИ ТРУБОПРОВОДОВ ФИЛЬТРАТА

Необходимость определения пропускной способности трубопроводов фильтрата дисковых вакуум-фильтров возникает, например, при увеличении нагрузки на фильтры, изменении характеристик питания, режимов фильтрова-ния или при появлении участков трубопроводов, в которых износ от трения привел к потере герметичности и к необходимости замены отдельных участков. Пропускная способность трубопровода зависит от его конструкции и от условий на входе и выходе. На вход в трубопровод поступает фильтрат, про-шедший через слой осадка и фильтровальную перегородку. В настоящее время из-за снижения крупности частиц твердого, поступающих на флотацию, пита-ние флотации принимают разбавленным, что снижает содержание твердого и в питании фильтров. При разбавленном и мелкозернистом материале фильтро-вальные диски не полностью покрыты слоем осадка, и он оказывается слишком тонким. Это приводит к снижению вакуума в вакуумной системе фильтрата

Influence of diesel surrogates on the behavior of simplified spray models

Numerous experimental investigations make use of diesel surrogates to make the computational time reasonable. In the few studies where measured (surrogate and real diesel) and computed (surrogate only) results have been compared, the selection methodology for the surrogate constituent compounds and the measures taken to validate the chemical kinetic models are not discussed, and the range of operating conditions used is often small. Additionally, most simplified models use tuning variables to fit model results to measurements. This work makes the comparison between some frequently used diesel surrogates using a simple 1D vaporizing spray model, with the spray cone angle as the tuning parameter. Results show that liquid length and fuel fraction strongly depend on the physical properties of the used fuel for a fixed spray angle. These parameters are important for modeling auto-ignition and pollutant formation. The spray angle is varied till the spray length is the same for each surrogate. Results show important differences between other spray parameters such as local mixture fraction and axial velocity