4,285 research outputs found
Human Segmentation In Funerary Practices. The Middle Neolithic Cemetery Cave Of Bom Santo (Montejunto Mountain Range, Portugal)
UID/ANT/04038/2019
IF/00127/2014Ongoing multidisciplinary studies of skeletonized human remains from the Middle Neolithic Bom Santo Cave (Lisbon, Portugal) is indicating a very heterogeneous population at various levels (diets, mobility and genetics). The current interpretation suggests that its socioeconomic and funerary territories encompassed the lower Tagus, its tributaries and the granitic sectors of the Mora–Pavia area in the Alentejo. Archaeothanatological analyses indicated mutually exclusive funerary practices: secondary depositions at Room A and primary and secondary depositions at Room B. Polished stone tools are evenly distributed in both rooms, while ornaments, pottery, flint blades and sheep/goat phalanges are almost restricted to Room A. Such distribution patterns reflects the coexistence of distinct funerary practices in which Room A is part of a much complex behaviour that included primary depositions, exhumation, transportation and re-deposition of human bone remains between different sectors of the cave and/or cemeteries (caves, dolmens) of the above-described territory. Thus, a more dynamic (in its rituals) and wider (in its geography) set of funerary practices than usually perceived — in which the intentional segmentation of human skeletons is attested — seems to have taken place at the onset of megalithism in central-southern Portugal.publishersversionpublishe
Fold-Saddle Bifurcation in Non-Smooth Vector Fields on the Plane
This paper presents results concerning bifurcations of 2D piecewise-smooth
dynamical systems governed by vector fields. Generic three parameter families
of a class of Non-Smooth Vector Fields are studied and its bifurcation diagrams
are exhibited. Our main result describes the unfolding of the so called
Fold-Saddle singularity
Performance Investigations of IEEE 802.11 a54 Mbps WPA2 Laboratory Links
The increasing importance of wireless communications, involving electronic devices, has been widely recognized. Performance is a fundamental issue, resulting in more reliable and efficient communications. Security is also crucially important. Laboratory measurements are presented for several performance aspects of Wi-Fi IEEE 802.11a54 Mbps WPA2 point-to-point and four node point-to-multipoint links. Our study contributes to performance evaluation of this technology under WPA2 encryption, using available equipment (HP V-M200 access points and Linksys WPC600N adapters). New results are given from TCP and UDP experiments concerning TCP throughput versus TCP packet length, jitter and percentage datagram loss versus UDP datagram size. Comparisons are made to corresponding results for Open links. Conclusions are drawn about the comparative performance of the links.
Keywords: Wi-Fi, WLAN, IEEE 802.11a, Wireless network laboratory performance, Multi-Node WPA2 link
Performance Evaluation of IEEE 802.11 ac WPA2 Laboratory Links
The increasing importance of wireless communications, involving electronic devices, has been widely recognized. Performance is a fundamental issue, resulting in more reliable and efficient communications. Security is also crucially important. Laboratory measurements are presented about several performance aspects of Wi-Fi IEEE 802.11ac WPA2 point-to-point links. Our study contributes to performance evaluation of this technology under WPA2 encryption, using available equipment (Cisco 2702i access points and TP-Link AC1900 USB 3.0 adapters). New results are given from TCP and UDP experiments concerning TCP throughput versus TCP packet length, jitter and percentage datagram loss versus UDP datagram size. Comparisons are made to corresponding results for WPA2 802.11n. Conclusions are drawn about the comparative performance of the links.
Keywords: Wi-Fi, WLAN, IEEE 802.11ac, Wireless network laboratory performance, Point-to-Point WPA2 link
Transport properties of pristine few-layer black phosphorus by van der Waals passivation in an inert atmosphere
Ultrathin black phosphorus is a two-dimensional semiconductor with a sizeable band gap. Its excellent electronic properties make it attractive for applications in transistor, logic and optoelectronic devices. However, it is also the first widely investigated two-dimensional material to undergo degradation upon exposure to ambient air. Therefore a passivation method is required to study the intrinsic material properties, understand how oxidation affects the physical properties and enable applications of phosphorene. Here we demonstrate that atomically thin graphene and hexagonal boron nitride can be used for passivation of ultrathin black phosphorus. We report that few-layer pristine black phosphorus channels passivated in an inert gas environment, without any prior exposure to air, exhibit greatly improved n-type charge transport resulting in symmetric electron and hole transconductance characteristics.B.O. acknowledges support by the National Research Foundation, Prime Minister's Office, Singapore under its Competitive Research Programme (CRP Award No. NRF-CRP9-2011-3) and the SMF-NUS Research Horizons Award 2009-Phase II. A.H.C.N. acknowledges the NRF-CRP award 'Novel 2D materials with tailored properties: beyond graphene'. The calculations were performed at the GRC computing facilities. A.Z. and D.F.C. acknowledge the NSF grant CHE-1301157. (NRF-CRP9-2011-3 - National Research Foundation, Prime Minister's Office, Singapore under its Competitive Research Programme (CRP); SMF-NUS Research Horizons Award-Phase II; NRF-CRP award 'Novel 2D materials with tailored properties: beyond graphene'; CHE-1301157 - NSF)Published versio
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