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Yinan Cui, Giacomo Po, Nasr Ghoniem
We demonstrate, through three-dimensional discrete dislocation dynamics simulations, that the complex dynamical response of nano- and microcrystals to external constraints can be tuned. Under load rate control, strain bursts are shown to exhibit scale-free avalanche statistics, similar to critical phenomena in many physical systems. For the other extreme of displacement rate control, strain burst response transitions to quasiperiodic oscillations, similar to stick-slip earthquakes. External load mode control is shown to enable a qualitative transition in the complex collective dynamics of dislocations from self-organized criticality to quasiperiodic oscillations...
October 7, 2016: Physical Review Letters
Madhav V Deo
A buzzword in Indian press and amongst the policy makers is that India is short of the WHO recommended doctor to population ratio of 1:1000. The recommendations were formulated to facilitate programs to achieve some of the health related UN-Millennium Development Goals (MDGs). Infections and malnutrition, which can be comfortably handled by a basic MBBS doctor, were the dominant health issues at the time of the formulation of the MDGs. However, all countries worldwide are going through health epidemiological transition and health impact of the non-communicable disorders (NCDs) can be no more ignored even by the low income nations...
October 2016: Journal of the Association of Physicians of India
Angelo Gulinatti, Francesco Ceccarelli, Ivan Rech, Massimo Ghioni
In order to fulfill the requirements of many applications, we recently developed a new technology aimed at combining the advantages of traditional thin and thick silicon Single Photon Avalanche Diodes (SPAD). In particular we demonstrated single-pixel detectors with a remarkable improvement in the Photon Detection Efficiency in the red/near-infrared spectrum (e.g. 40% at 800nm) while maintaining a timing jitter better than 100ps. In this paper we discuss the limitations of such Red-Enhanced (RE) technology from the point of view of the fabrication of small arrays of SPAD and we propose modifications to the structure aimed at overcoming these issues...
April 17, 2016: Proceedings of SPIE
Rebecca Re, Edoardo Martinenghi, Alberto Dalla Mora, Davide Contini, Antonio Pifferi, Alessandro Torricelli
We report the development of a compact probe for time-domain (TD) functional near-infrared spectroscopy (fNIRS) based on a fast silicon photomultiplier (SiPM) that can be put directly in contact with the sample without the need of optical fibers for light collection. We directly integrated an avalanche signal amplification stage close to the SiPM, thus reducing the size of the detection channel and optimizing the signal immunity to electromagnetic interferences. The whole detection electronics was placed in a plastic screw holder compatible with the electroencephalography standard cap for measurement on brain or with custom probe holders...
October 2016: Neurophotonics
Naïma Gaudel, Sébastien Kiesgen de Richter, Nicolas Louvet, Mathieu Jenny, Salaheddine Skali-Lami
In this article, we study granular avalanches when external mechanical vibrations are applied. We identify conditions of flow arrest and compare with the ones classically observed for nonvibrating granular flows down inclines [Phys. Fluids 11, 542 (1999)PHFLE61070-663110.1063/1.869928]. We propose an empirical law to describe the thickness of the deposits with the inclination angle and the vibration intensity. The link between the surface velocity and the depth of the flow highlights a competition between gravity and vibrations induced flows...
September 2016: Physical Review. E
Víctor Navas-Portella, Álvaro Corral, Eduard Vives
Similarities between force-driven compression experiments of porous materials and earthquakes have been recently proposed. In this paper, we measure the acoustic emission during displacement-driven compression of a porous glass. The energy of acoustic-emission events shows that the failure process exhibits avalanche scale-invariance and therefore follows the Gutenberg-Richter law. The resulting exponents do not exhibit significant differences with respect the force-driven case. Furthermore, the force exhibits an avalanche-type behavior for which the force drops are power-law distributed and correlated with the acoustic emission events...
September 2016: Physical Review. E
Bhoopal Rao Gangadari, Shaik Rafi Ahamed
In biomedical, data security is the most expensive resource for wireless body area network applications. Cryptographic algorithms are used in order to protect the information against unauthorised access. Advanced encryption standard (AES) cryptographic algorithm plays a vital role in telemedicine applications. The authors propose a novel approach for design of substitution bytes (S-Box) using second-order reversible one-dimensional cellular automata (RCA(2)) as a replacement to the classical look-up-table (LUT) based S-Box used in AES algorithm...
September 2016: Healthcare Technology Letters
Shabieh Farwa, Tariq Shah, Lubna Idrees
We study the structure of an S-box based on a fractional linear transformation applied on the Galois field [Formula: see text]. The algorithm followed is very simple and yields an S-box with a very high ability to create confusion in the data. The cryptographic strength of the new S-box is critically analyzed by studying the properties of S-box such as nonlinearity, strict avalanche, bit independence, linear approximation probability and differential approximation probability. We also apply majority logic criterion to determine the effectiveness of our proposed S-box in image encryption applications...
2016: SpringerPlus
Nicholas M Timme, Najja J Marshall, Nicholas Bennett, Monica Ripp, Edward Lautzenhiser, John M Beggs
The analysis of neural systems leverages tools from many different fields. Drawing on techniques from the study of critical phenomena in statistical mechanics, several studies have reported signatures of criticality in neural systems, including power-law distributions, shape collapses, and optimized quantities under tuning. Independently, neural complexity-an information theoretic measure-has been introduced in an effort to quantify the strength of correlations across multiple scales in a neural system. This measure represents an important tool in complex systems research because it allows for the quantification of the complexity of a neural system...
2016: Frontiers in Physiology
V Uhlíř, J A Arregi, E E Fullerton
Coupled order parameters in phase-transition materials can be controlled using various driving forces such as temperature, magnetic and electric field, strain, spin-polarized currents and optical pulses. Tuning the material properties to achieve efficient transitions would enable fast and low-power electronic devices. Here we show that the first-order metamagnetic phase transition in FeRh films becomes strongly asymmetric in mesoscale structures. In patterned FeRh stripes we observed pronounced supercooling and an avalanche-like abrupt transition from the ferromagnetic to the antiferromagnetic phase, while the reverse transition remains nearly continuous over a broad temperature range...
October 11, 2016: Nature Communications
Bhoopal Rao Gangadari, Shaik Rafi Ahamed
In this paper, we presented a novel approach of low energy consumption architecture of S-Box used in Advanced Encryption Standard (AES) algorithm using programmable second order reversible cellular automata (RCA (2)). The architecture entails a low power implementation with minimal delay overhead and the performance of proposed RCA (2) based S-Box in terms of security is evaluated using the cryptographic properties such as nonlinearity, correlation immunity bias, strict avalanche criteria, entropy and also found that the proposed architecture is secure enough for cryptographic applications...
December 2016: Journal of Medical Systems
Chien-Shun Yan, Yao-Nan Wang
A multi-parameter optofluidic cytometer based on two low-cost commercial photovoltaic cells and an avalanche photodetector is proposed. The optofluidic cytometer is fabricated on a polydimethylsiloxane (PDMS) substrate and is capable of detecting side scattered (SSC), extinction (EXT) and fluorescence (FL) signals simultaneously using a free-space light transmission technique without the need for on-chip optical waveguides. The feasibility of the proposed device is demonstrated by detecting fluorescent-labeled polystyrene beads with sizes of 3 μm, 5 μm and 10 μm, respectively, and label-free beads with a size of 7...
September 1, 2016: Biomedical Optics Express
V Brajuskovic, F Barrows, C Phatak, A K Petford-Long
Artificial spin ice lattices have emerged as model systems for studying magnetic frustration in recent years. Most work to date has looked at periodic artificial spin ice lattices. In this paper, we observe frustration effects in quasicrystal artificial spin ice lattices that lack translational symmetry and contain vertices with different numbers of interacting elements. We find that as the lattice state changes following demagnetizing and annealing, specific vertex motifs retain low-energy configurations, which excites other motifs into higher energy configurations...
October 3, 2016: Scientific Reports
Øyvind Sverre Svendsen, Ketil Grong, Knut Sverre Andersen, Paul Husby
BACKGROUND: Accidental hypothermia with arrested circulation remains a condition associated with high mortality. In our institution, extracorporeal circulation (ECC) rewarming has been the cornerstone in treating such patients since 1987. We here explore characteristics and outcomes of this treatment, to identify significant merits and challenges from 3 decades of experience in ECC rewarming. METHODS: Sixty-nine patients rewarmed by ECC during the period from December 1987 to December 2015 were analyzed...
September 27, 2016: Annals of Thoracic Surgery
Chester E Sutterlin
At noon on Saturday, 25 April 2015, a 7.8 magnitude earthquake struck Nepal. It was centered in the Himalaya northwest of Kathmandu, the capital of over 1 million people. The violent tremors were felt as far away as New Delhi, India 1,000 km from the epicenter, but the worst of its destructive force was experienced in the heavily populated Kathmandu valley and in the remote mountainous villages of the Himalaya. Ancient temples crumbled; poorly constructed buildings collapsed; men, women, and children were trapped and injured, sometimes fatally...
December 2015: J Spine Surg
M Kobek, R Skowronek, C Jabłoński, Z Jankowski, A Pałasz
On 28 January 2003 snow avalanche in the Polish Tatras happened, in which 8 people died and 5 were injured. We tried to determine cause and manner of death in 6 fatal victims instead of advanced late post mortem changes in internal organs. Taking into consideration the circumstances of death, we paid special attention to histopathological examination of lungs, extended by Gomori's and AZAN staining. Pattern of the changes was similar to those observed in forensic medicine in cases of asphyxia due to airway obstruction and/or immobilization of chest and abdomen (Perthes' syndrome)...
2016: Archiwum Medycyny Sa̧dowej i Kryminologii
Erum Jamil, Jeng S Cheong, J P R David, Majeed M Hayat
Simple, approximate formulas are developed to calculate the mean gain and excess noise factor for avalanche photodiodes using the dead-space multiplication theory in the regime of small multiplication width and high applied electric field. The accuracy of the approximation is investigated by comparing it to the exact numerical method using recursive coupled integral equations and it is found that it works for dead spaces up to 15% of the multiplication width, which is substantial. The approximation is also tested for real materials such as GaAs, InP and Si for various multiplication widths, and the results found are accurate within ∼ 15% of the actual noise, which is a significant improvement over the local-theory noise formula...
September 19, 2016: Optics Express
Jian Ma, Bing Bai, Liu-Jun Wang, Cun-Zhu Tong, Ge Jin, Jun Zhang, Jian-Wei Pan
InGaAs/InP single-photon avalanche diodes (SPADs) are widely used in practical applications requiring near-infrared photon counting such as quantum key distribution (QKD). Photon detection efficiency and dark count rate are the intrinsic parameters of InGaAs/InP SPADs, due to the fact that their performances cannot be improved using different quenching electronics given the same operation conditions. After modeling these parameters and developing a simulation platform for InGaAs/InP SPADs, we investigate the semiconductor structure design and optimization...
September 20, 2016: Applied Optics
Carlos Wiechers, Roberto Ramírez-Alarcón, Oscar R Muñiz-Sánchez, Pablo Daniel Yépiz, Alejandro Arredondo-Santos, Jorge G Hirsch, Alfred B U'Ren
We present a method designed to efficiently extract optical signals from InGaAs avalanche photodiodes (APDs) operated in gated mode. In particular, our method permits an estimation of the fraction of counts that actually results from the signal being measured, as opposed to being produced by noise mechanisms, specifically by afterpulsing. Our method in principle allows the use of InGaAs APDs at high detection efficiencies, with the full operation bandwidth, either with or without resorting to the application of a dead-time...
September 10, 2016: Applied Optics
Peng-Yuan Lu, Xing-Guo Yang, Fu-Gang Xu, Tian-Xing Hou, Jia-Wen Zhou
Substrate entrainment can greatly influence the mass movement process of a debris avalanche because it can enlarge the landslide volume and change the motion characteristics of the sliding masses. To study the interaction between debris avalanches and erodible substrate, physical modeling experiments varying in the mass of granular flow and substrate thickness were performed. The experimental results show that both the entrained materials and the maximum erosion depth are increased with increasing mass of the debris avalanche and decreasing substrate thickness...
2016: SpringerPlus
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