2,162 research outputs found
Mangarara Formation: exhumed remnants of a middle Miocene, temperate carbonate, submarine channel-fan system on the eastern margin of Taranaki Basin, New Zealand
No full textThe middle Miocene Mangarara Formation is a thin (1–60 m), laterally discontinuous unit of moderately to highly calcareous (40–90%) facies of sandy to pure limestone, bioclastic sandstone, and conglomerate that crops out in a few valleys in North Taranaki across the transition from King Country Basin into offshore Taranaki Basin. The unit occurs within hemipelagic (slope) mudstone of Manganui Formation, is stratigraphically associated with redeposited sandstone of Moki Formation, and is overlain by redeposited volcaniclastic sandstone of Mohakatino Formation. The calcareous facies of the Mangarara Formation are interpreted to be mainly mass-emplaced deposits having channelised and sheet-like geometries, sedimentary structures supportive of redeposition, mixed environment fossil associations, and stratigraphic enclosure within bathyal mudrocks and flysch. The carbonate component of the deposits consists mainly of bivalves, larger benthic foraminifers (especially Amphistegina), coralline red algae including rhodoliths (Lithothamnion and Mesophyllum), and bryozoans, a warm-temperate, shallow marine skeletal association. While sediment derivation was partly from an eastern contemporary shelf, the bulk of the skeletal carbonate is inferred to have been sourced from shoal carbonate factories around and upon isolated basement highs (Patea-Tongaporutu High) to the south. The Mangarara sediments were redeposited within slope gullies and broad open submarine channels and lobes in the vicinity of the channel-lobe transition zone of a submarine fan system. Different phases of sediment transport and deposition (lateral-accretion and aggradation stages) are identified in the channel infilling. Dual fan systems likely co-existed, one dominating and predominantly siliciclastic in nature (Moki Formation), and the other infrequent and involving the temperate calcareous deposits of Mangarara Formation. The Mangarara Formation is an outcrop analogue for middle Miocene-age carbonate slope-fan deposits elsewhere in subsurface Taranaki Basin, New Zealand
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Integrated fan cooling of the lower back for wheelchair users
No full textIntroduction: A large proportion of a wheelchair user's body is in contact with their wheelchair. Integrated fan cooling systems fitted to a wheelchair's backrest aim to alleviate the build-up of heat at the skin-chair interface. The aim of this pilot study was to evaluate the effectiveness of an integrated fan cooling system at cooling the user during daily pushing activity.
Methods: Eight male able-bodied participants completed two conditions, with (FAN) and without (CON) fan cooling, pushing for four 15 min blocks. The fan was turned on (highest setting) at the end of block 1 (FAN), whilst in CON the fan remained off. Skin temperature was measured over the back and chest throughout alongside heart rate and perceptual responses (rating of perceived exertion, thermal sensation, thermal comfort, wetness sensation) at the end of each 15 min block.
Results: Wetness sensation and lower back skin temperature were lower in FAN (both p < 0.02), with the difference in lower back skin temperature between the two conditions being 2.20°C at the end of block 4.
Conclusion: The integrated fan cooling system provided significant cooling to the lower back without affecting any other physiological or perceptual response, besides wetness sensation
A 7.9 fJ/conversion-step 10-bit 125 MS/s SAR ADC with Simplified Power-efficient Digital Control Logic
No full textThis paper presents a 7.9 fJ /conversion-step 10-bit 125 MS/s successive approximation register(SAR) analog-to-digital converter(ADC) on the basis of a monotonic capacitor switching procedure. Simplified power-efficient digital control logic, multi-layer sandwich capacitor structure and high-speed level-shift bootstrapped sampling-and-holding(S/H) blocks are employed to achieve high performance with low power consumption. The prototype is implemented in 55 nm standard CMOS process, occupying an active area of 0.18 mm × 0.20 mm. Post simulation results show that an SNDR of 54.01 d B and an ENOB of 8.7 bit can be achieved by consuming 0.41 mW of the ADC core from a 1.2 V supply, and a figure of merit(FOM) of 7.9 fJ /conversion-step.This paper presents a 7.9 fJ /conversion-step 10-bit 125 MS/s successive approximation register(SAR) analog-to-digital converter(ADC) on the basis of a monotonic capacitor switching procedure. Simplified power-efficient digital control logic, multi-layer sandwich capacitor structure and high-speed level-shift bootstrapped sampling-and-holding(S/H) blocks are employed to achieve high performance with low power consumption. The prototype is implemented in 55 nm standard CMOS process, occupying an active areaIEEE Beijing Section
Enhanced multiparty quantum secret sharing of classical messages by using entanglement swapping
No full text[[abstract]]Based on the multiparty quantum secret sharing (QSS) protocol called Zhang-Man protocol, the authors proposed two schemes to enhance the transmission efficiency of whole protocol. In the proposed improved protocol, the dealer can transmit double amount of secret messages at a time securely instead of doing the original Zhang-Man protocol twice. Besides, the authors save a lot of cost of whole QSS system. When the amount of secret messages is large and the number of agents is more, the performance of our protocol is much better than the Zhang-Man protocol. The authors also proposed a reuse scheme, after the secret message had been deduced, the left qubits can be reused for a new round. All of the scheme the authors mentioned above could be extended to multiparty cases in practice.[[note]]SC
81 fJ/bit energy-to-data ratio of 850 nm vertical-cavity surface-emitting lasers for optical interconnects
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 98, 231106 (2011) and may be found at https://doi.org/10.1063/1.3597799.Extremely energy-efficient oxide-confined high-speed 850 nm vertical-cavity surface-emitting lasers for optical interconnects are presented. Error-free performance at 17 and 25 Gb/s via a 100 m multimode fiber link is demonstrated at record high dissipation-power-efficiencies of up to 69 fJ/bit (<0.1mW/Gbps) and 99 fJ/bit, respectively. These are the most power efficient high-speed directly modulated light sources reported to date. The total energy-to-data ratio is 83 fJ/bit at 25°C and reduces to 81 fJ/bit at 55°C. These results were obtained without adjustment of driving conditions. A high -factor of 12.0GHz/(mA)0.5 and a -factor of 0.41 ns are measured.EC/FP7/224211/EU/VISIT - Vertically Integrated Systems for Information Transfer/VISITDFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, Bauelement
JunB/AP-1 controls MM cell proliferation, survival and drug resistance in the bone marrow microenvironment
No full textThe AP-1 Transcription Factor JunB Promotes Multiple Myeloma (MM) Cell Proliferation, Survival and Drug Resistance in the Bone Marrow Microenvironment
No full textSingle-drive high-speed lumped depletion-type modulators toward 10 fJ/bit energy consumption
No full textReduction of modulator energy consumption to 10 fJ/bit is essential for the sustainable development of communication systems. Lumped modulators might be a viable solution if instructed by a complete theory system. Here, we present a complete analytical electro-optic response theory, energy consumption analysis, and eye diagrams on absolute scales for lumped modulators. Consequently the speed limitation is understood and alleviated by single-drive configuration, and comprehensive knowledge into the energy dependence on structural parameters significantly reduces energy consumption. The results show that silicon modulation energy as low as 80.8 and 21.5 fJ/bit can be achieved at 28 Gbd under 50 and 10 Omega impedance drivers, respectively. A 50 Gbd modulation is also shown to be possible. The analytical models can be extended to lumped modulators on other material platforms and offer a promising solution to the current challenges of modulation energy reduction. (C) 2017 Chinese Laser PressNational Natural Science Foundation of China (NSFC) [61120106012]SCI(E)ARTICLE2134-142
Optimization of a piezoelectric fan using fluid-structure interaction simulation
No full textIn this paper, the heat transfer from a single heat fin to the air flow in the wake of a piezoelectric fan (piezofan) is optimised. Both the heat fin and the piezofan are positioned in a channel, which has a significant influence on the flow field. The design variable is the frequency of the voltage applied to the piezofan. The heat transfer for different excitation frequencies is calculated using unsteady fluid-structure interaction simulations. To obtain a modular simulation environment, the flow equations and the structural equations are solved separately. However, the equilibrium on the fluid-structure interface is not satisfied automatically in this partitioned approach. Therefore, the interface quasi-Newton technique with an approximation for the inverse of the Jacobian from a least-squares model (IQN-ILS) is used to perform coupling iterations between the flow solver and the structural solver in each time step. With the unsteady fluid-structure interaction model, a surrogate model is constructed. The optimization of the surrogate model yields a frequency close to the first eigenfrequency of the structure
Performance Guarantees for Distributed Reachability Queries
No full textIn the real world a graph is often fragmented and distributed across different sites. This highlights the need for evaluating queries on distributed graphs. This paper proposes distributed evaluation algorithms for three classes of queries: reachability for determining whether one node can reach another, bounded reachability for deciding whether there exists a path of a bounded length between a pair of nodes, and regular reachability for checking whether there exists a path connecting two nodes such that the node labels on the pathform a string in a given regular expression. We develop these algorithms based on partial evaluation, to explore parallel computation. When evaluating a query Q on a distributed graph G, we show that these algorithms possess the following performance guarantees, no matter how G is fragmented and distributed: (1) each site is visited only once; (2) the total network traffic is determined by the size of Q and the fragmentation of G, independent of the size of G; and (3) the response time is decided by the largest fragment of Grather than the entire G. In addition, we show that these algorithms can be readily implemented in the MapReduce framework. Using synthetic and real-life data, we experimentally verify that these algorithms are scalable on large graphs, regardless of how the graphs are distributed
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