Analysis of a nip impinged, three-dimensional wound roll

Scope and Method of Study: An accurate, nip impinged, three dimensional wound roll model can improve the quality of numerous consumer products. This is because the products use webs that were once wound into a roll. The model identifies potentially destructive stress levels without actually winding, thereby reducing waste, and boosting efficiency. To this end, it integrates a three dimensional roll sub-model, with a peripheral nip contact sub-model, in a recursive exchange. The three dimensional sub-model is an orthotropic, axisymmetric-quadrilateral finite element model that accretes by interfering layers onto each other. It incorporates thickness variations in the web profile in the CMD, variable core configurations, and wound on tension iteration. The peripheral nip sub-model is a linked system of beam finite elements. A winkler elastic foundation, with a non-linear radial stiffness, represents the wound roll, which is radiatively coupled to both the impinging nip, and the core. Control passes back and forth between the submodels as each contributes to the final nip impinged, three dimensional roll.Findings and Conclusions: The combined model is a significant step forward in wound roll simulations. The underlying axisymmetric sub-model is one of the most extensive, and accurate, known to exist. Its CMD radii, and stresses, compared well to experimental data. It captured the tension concentration, and radius buildup, recognized to correspond with thicker CMD locations. When combined with the nip sub-model, the result is the first, and only, model known to also incorporate the CMD compression, and load distribution, effects of nip impingement. Its results show the nip load concentrates at higher locations to reduce their radii. And, its comparison to the 14 pound, six inch wide PET web experimental data was good. Ultimately, the combined model promises versatility, and utility, in its application to improve the quality of wound rolls in industry

Geoarchaeological and bioarchaeological studies at Mira, an early Upper Paleolithic site in the Lower Dnepr Valley, Ukraine

New geoarchaeological and bioarcheological research was undertaken at the open-air site of Mira, which is buried in deposits of the Second Terrace of the Dnepr River, roughly 15 km downstream from the city of Zaporozhye in Ukraine. Previous excavation of the site revealed two occupation layers dating to ∼32,000 cal BP. The lower layer (II/2) yielded bladelets similar to those of the early Gravettian, while the upper layer (I) contained traces of an artificial shelter and hundreds of bones and teeth of horse (Equus latipes). Mira represents the only firmly dated early Upper Paleolithic (EUP) site in the Dnepr Basin, and occupies a unique topographic setting for the EUP near the center of the broad floodplain of the Dnepr River. The site was visited during a period of floodplain stability, characterized by overbank deposition and weak soil formation under cool climate conditions. Mira was used as a long-term camp, but also was the locus of large-mammal carcass processing associated with a nearby kill of a group of horses (Layer I)

Kostenki 1 and the early Upper Paleolithic of Eastern Europe

Although best known for its spectacular Gravettian features and art, the open-air site of Kostenki 1 (located near Voronezh on the Don River [Russian Federation]) also has played an important role in the study of the early Upper Paleolithic (EUP) of Eastern Europe. New excavations at Kostenki 1 were undertaken in 2004-2012 with a focus on the EUP layers (Layers III-V), which represent temporal zones of recurring occupation, buried in low-energy slope deposits (5% slope). Soils formed during periods of increased surface stability. A new set of radiocarbon estimates on wood charcoal indicates that Layer III dates between 33,000 and 38,000. cal BP. Layer V underlies the CI tephra (~ 40,000. cal BP), which is redeposited and identified only by microscopic analysis of sediment samples in most of the (downslope) areas of the site excavated during 2004-2012. Large and medium mammal remains recovered from the EUP layers include mammoth, horse, reindeer, arctic fox, and wolf, and taphonomic analyses indicate that carcasses were processed at the site. All EUP layers yielded artifacts typical of the East European Strelets industry (e.g., bifaces, side-scrapers), but earlier excavation (1948-1953) of Layer III also produced diagnostic Aurignacian artifacts (e.g., carinated scrapers, retouched bladelets). The new chronology for Layer III suggests an association between the Aurignacian of the central East European Plain and the warm intervals (GI 8-GI 7) following the HE4 cold period (~ 38,000-40,000. cal BP)