112 research outputs found
Design of Drum Type Apparatus for Processing of Bulk Materials
The article presents the development and research of drum continuous mixers, most attention is paid to the results of theoretical (using of cybernetic approach) and experimental studies of longitudinal mixing particulate material in rotating drums of continuous action, the influence of internal recycles of material flows, intensifying the process of smoothing the input fluctuations. The authors analyzed the influence of internal recycles material flows, intensifying the process of smoothing the input fluctuations. The results presented in this paper were obtained by the experiments on the smoothing ability determination during which they change the frequency of the drum rotation, the location of the Г-shaped mixer blades on the drum mixer. The article reported that the studies were conducted on three mixtures which components have different physical and mechanical systems with various dispersed liquid additives and without it
Steady and Stable: Numerical Investigations of Nonlinear Partial Differential Equations
Excerpt: Mathematics is a language which can describe patterns in everyday life as well as abstract concepts existing only in our minds. Patterns exist in data, functions, and sets constructed around a common theme, but the most tangible patterns are visual. Visual demonstrations can help undergraduate students connect to abstract concepts in advanced mathematical courses. The study of partial differential equations, in particular, benefits from numerical analysis and simulation
a sedimentological record of early miocene ice advance and retreat and 2a drill hole mcmurdo sound antarctica
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New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
Sedimentary environments of the Cenozoic sedimentary debris found in the moraines of the Grove Mountains, east Antarctic and its climatic implications*
Mid-Tertiary macroinvertebrate-rich clasts from the Battye Glacier Formation, Prince Charles Mountains, East Antarctica
Macrofossils discovered in the Battye Glacier Formation (Pagodroma Group) of the Prince Charles Mountains, East Antarctica, provide important insight into marine life of the mid-Tertiary, rarely preserved elsewhere on the continent. Recorded are five species of macroinvertebrates; these are Adamussium n. sp.? cf.colbecki (Smith, 1902) (Bivalvia), Laternula? sp. (Laternulidae), Mytilidae genus and species indeterminate (Bivalvia), Bivalvia genus and species indeterminate, and Polychaeta genus and species indeterminate. Based on stratigraphcal data and faunal composition, the clasts are dated as no younger than Early Miocene. This is one of the oldest reports of Adamussium from Antarctica, previously known from the Late Pliocene to Recent with a possible record in the Late Oligocene-Early Miocene. Palaeoecological data and facies analysis indicate
that these taxa inhabited a shallow- to mid-shelf marine environment of normal salinity that was oligotrophic.
The substrate was a soft, pebbly and sandy bottom that was sufficiently mobile to sponsor deep burrowing forms
Mid-Tertiary macroinvertebrate-rich clasts from the Battye Glacier Formation, Prince Charles Mountains, East Antarctica
Glaciation across the Oligocene-Miocene boundary in southern McMurdo Sound, Antarctica: new chronology from the CIROS-1 drill hole
Few Palaeogene and Neogene sediment cores from the Antarctic continental margin have been dated with sufficient precision to enable establishment of direct linkages between glacial events on the Antarctic continent and marked events in deep-sea [delta]18O records. As a result, much of our knowledge of the gradual, but stepwise, shift from 'greenhouse' climates of the Cretaceous to the 'ice-house' climates of the Quaternary is inferred from well-dated and more continuously deposited deep-sea sediments. In this study, we present new magnetostratigraphic results from the CIROS-1 drill core from McMurdo Sound, Antarctica, along with a reinterpretation of a published diatom biostratigraphic zonation that is constrained by correlation to a high-precision age model from the nearby CRP-2/2A drill core. Our results suggest that most of the upper 350 m of the CIROS-1 drill core represents rapid sediment accumulation during a short time interval spanning the Oligocene-Miocene boundary. Chronostratigraphic control is precise enough to enable correlation of this interval of glacimarine sedimentation with the Mi-1 deep-sea [delta]18O event, which confirms that the Mi-1 event was related to a major expansion of Antarctic ice. A major unconformity at 366 m in the CIROS-1 drill core, which is widely observed in regional seismic reflection studies, represents 9 Myr of missing time. This unconformity can be traced offshore into the Ross Sea using seismic stratigraphy and is interpreted to indicate significant East Antarctic ice sheet development during the Mi-1 glaciation. The stratigraphic expression of this ~400-kyr glacial event is evidently multiphase and complex in the Victoria Land Basin, probably because it was punctuated by higher-frequency orbitally induced glacial oscillations. The presence of Nothofagidites pollen throughout the CIROS-1 drill core and the presence of a Nothofagus (Southern beech) leaf within the early Miocene portion of the core indicate that Antarctic mean summer temperatures did not decrease below 5[deg]C throughout the Mi-1 glaciation. These temperatures are significantly warmer than present-day mean summer temperatures at sea level in McMurdo Sound. The persistence of a Nothofagus forest in coastal southern Victoria Land throughout this time interval suggests that the present state of deep refrigeration was not reached until some time after the Mi-1 glaciatio
Trochosira polychaeta: a colonial diatom from the late Cretaceous exhibiting two contrasting chain-linking mechanisms and a wide range of preservation
The fossil species Trochosira polychaeta Strelnikova, exhibits a wide range of preservational states that has led to contrasting interpretations with regard to its resting stage or vegetative cell status. Within shallow-buried, well preserved diatomites from the Alpha Ridge of the Arctic Ocean, a continuum of dissolution effects are documented and a vegetative cell status is clearly indicated. The chains are formed by a central linking process but complex marginal structures also constitute a complementary linking mechanism. The double linkage may have supported the integrity of the colonial chains and provided a mechanism for enhanced nutrient uptake. The presence of two distinct types of linking might also represent a stage in a transition from the Cretaceous when central linking structures were common, through the Cenozoic to the modern with more common linking through marginal structures
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