WorldWideScience

Sample records for high-density memory circuit

  1. High density submicron magnetoresistive random access memory (invited)

    Science.gov (United States)

    Tehrani, S.; Chen, E.; Durlam, M.; DeHerrera, M.; Slaughter, J. M.; Shi, J.; Kerszykowski, G.

    1999-04-01

    Various giant magnetoresistance material structures were patterned and studied for their potential as memory elements. The preferred memory element, based on pseudo-spin valve structures, was designed with two magnetic stacks (NiFeCo/CoFe) of different thickness with Cu as an interlayer. The difference in thickness results in dissimilar switching fields due to the shape anisotropy at deep submicron dimensions. It was found that a lower switching current can be achieved when the bits have a word line that wraps around the bit 1.5 times. Submicron memory elements integrated with complementary metal-oxide-semiconductor (CMOS) transistors maintained their characteristics and no degradation to the CMOS devices was observed. Selectivity between memory elements in high-density arrays was demonstrated.

  2. High-Density Stacked Ru Nanocrystals for Nonvolatile Memory Application

    International Nuclear Information System (INIS)

    Ping, Mao; Zhi-Gang, Zhang; Li-Yang, Pan; Jun, Xu; Pei-Yi, Chen

    2009-01-01

    Stacked ruthenium (Ru) nanocrystals (NCs) are formed by rapid thermal annealing for the whole gate stacks and embedded in memory structure, which is compatible with conventional CMOS technology. Ru NCs with high density (3 × 10 12 cm −2 ), small size (2–4 nm) and good uniformity both in aerial distribution and morphology are formed. Attributed to the higher surface trap density, a memory window of 5.2 V is obtained with stacked Ru NCs in comparison to that of 3.5 V with single-layer samples. The stacked Ru NCs device also exhibits much better retention performance because of Coulomb blockade and vertical uniformity between stacked Ru NCs

  3. ChemicalVia: a CERN-patented technology for use in high-density circuits

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    High-density multilayer printed circuits such as those pictured here are found in miniaturized modern equipment from video cameras to mobile phones. Adjacent layers in these circuits are electrically connected by microvias, consisting of a small-diameter hole (usually 50 µm) with a thin metal-deposited surface covering their cylindrical walls to ensure local conductivity between the two layers. ChemicalVia is a new method, patented by CERN, to make microvias on high-density multilayer printed circuits using chemicals rather than complex laser, plasma or photoimaging technology. The process is compatible with all standard printed-circuit assembly lines, and has the advantages of low initial investment and reduced manufacturing costs. http://www.cern.ch/ttdatabase

  4. Fabrication technology for lead-alloy Josephson devices for high-density integrated circuits

    International Nuclear Information System (INIS)

    Imamura, T.; Hoko, H.; Tamura, H.; Yoshida, A.; Suzuki, H.; Morohashi, S.; Ohara, S.; Hasuo, S.; Yamaoka, T.

    1986-01-01

    Fabrication technology for lead-alloy Josephson devices was evaluated from the viewpoint of application to large-scale integrated circuits. Metal and insulating layers used in the circuits were evaluated, and optimization of techniques for deposition or formation of these layers was investigated. Metallization of the Pb-In-Au base electrode and the Pb-Bi counterelectrode was studied in terms of optimizing the deposited films, to improve the reliability of junction electrodes. The formation of the oxide barrier was studied by in situ ellipsometry. SiO/sub x/ deposited in oxygen was developed as the insulation layer with less defect density than conventional SiO. A liftoff technique using toluene soaking was developed, and patterns with a minimum line width of 2 μm were consistently reproduced. The characteristics of each element in the circuits were evaluated for test vehicles. For the junction, the following items were evaluated: controllability of the critical current I/sub c/, junction quality, I/sub c/ uniformity, junction yield, and thermal cycling and storage stability. For the peripheral elements, integrity of lines and contacts, and characteristics of resistors were evaluated. 8-kbit memory cell arrays with a full vertical structure were fabricated to evaluate these technologies in combination. The continuity of each metal layer and insulation between metal layers were evaluated with an autoprober at room temperature. For selected chips, cell characteristics have been measured, and their I/sub c/ uniformity and production yields for cells are discussed. Normal operation of the memory cells was confirmed for all of the 24 accessible cells on a chip

  5. Memory Circuit Fault Simulator

    Science.gov (United States)

    Sheldon, Douglas J.; McClure, Tucker

    2013-01-01

    Spacecraft are known to experience significant memory part-related failures and problems, both pre- and postlaunch. These memory parts include both static and dynamic memories (SRAM and DRAM). These failures manifest themselves in a variety of ways, such as pattern-sensitive failures, timingsensitive failures, etc. Because of the mission critical nature memory devices play in spacecraft architecture and operation, understanding their failure modes is vital to successful mission operation. To support this need, a generic simulation tool that can model different data patterns in conjunction with variable write and read conditions was developed. This tool is a mathematical and graphical way to embed pattern, electrical, and physical information to perform what-if analysis as part of a root cause failure analysis effort.

  6. Bipolar one diode-one resistor integration for high-density resistive memory applications.

    Science.gov (United States)

    Li, Yingtao; Lv, Hangbing; Liu, Qi; Long, Shibing; Wang, Ming; Xie, Hongwei; Zhang, Kangwei; Huo, Zongliang; Liu, Ming

    2013-06-07

    Different from conventional unipolar-type 1D-1R RRAM devices, a bipolar-type 1D-1R memory device concept is proposed and successfully demonstrated by the integration of Ni/TiOx/Ti diode and Pt/HfO2/Cu bipolar RRAM cell to suppress the undesired sneak current in a cross-point array. The bipolar 1D-1R memory device not only achieves self-compliance resistive switching characteristics by the reverse bias current of the Ni/TiOx/Ti diode, but also exhibits excellent bipolar resistive switching characteristics such as uniform switching, satisfactory data retention, and excellent scalability, which give it high potentiality for high-density integrated nonvolatile memory applications.

  7. Silicon photonics integrated circuits: a manufacturing platform for high density, low power optical I/O's.

    Science.gov (United States)

    Absil, Philippe P; Verheyen, Peter; De Heyn, Peter; Pantouvaki, Marianna; Lepage, Guy; De Coster, Jeroen; Van Campenhout, Joris

    2015-04-06

    Silicon photonics integrated circuits are considered to enable future computing systems with optical input-outputs co-packaged with CMOS chips to circumvent the limitations of electrical interfaces. In this paper we present the recent progress made to enable dense multiplexing by exploiting the integration advantage of silicon photonics integrated circuits. We also discuss the manufacturability of such circuits, a key factor for a wide adoption of this technology.

  8. Holographic memory for high-density data storage and high-speed pattern recognition

    Science.gov (United States)

    Gu, Claire

    2002-09-01

    As computers and the internet become faster and faster, more and more information is transmitted, received, and stored everyday. The demand for high density and fast access time data storage is pushing scientists and engineers to explore all possible approaches including magnetic, mechanical, optical, etc. Optical data storage has already demonstrated its potential in the competition against other storage technologies. CD and DVD are showing their advantages in the computer and entertainment market. What motivated the use of optical waves to store and access information is the same as the motivation for optical communication. Light or an optical wave has an enormous capacity (or bandwidth) to carry information because of its short wavelength and parallel nature. In optical storage, there are two types of mechanism, namely localized and holographic memories. What gives the holographic data storage an advantage over localized bit storage is the natural ability to read the stored information in parallel, therefore, meeting the demand for fast access. Another unique feature that makes the holographic data storage attractive is that it is capable of performing associative recall at an incomparable speed. Therefore, volume holographic memory is particularly suitable for high-density data storage and high-speed pattern recognition. In this paper, we review previous works on volume holographic memories and discuss the challenges for this technology to become a reality.

  9. A Fault Tolerant Integrated Circuit Memory

    OpenAIRE

    Barton, Anthony Francis

    1980-01-01

    Most commercially produced integrated circuits are incapable of tolerating manufacturing defects. The area and function of the circuits is thus limited by the probability of faults occurring within the circuit. This thesis examines techniques for using redundancy in memory circuits to provide fault tolerance and to increase storage capacity. A hierarchical memory architecture using multiple Hamming codes is introduced and analysed to determine its resistance to manufa...

  10. Ultra-High Density Holographic Memory Module with Solid-State Architecture

    Science.gov (United States)

    Markov, Vladimir B.

    2000-01-01

    NASA's terrestrial. space, and deep-space missions require technology that allows storing. retrieving, and processing a large volume of information. Holographic memory offers high-density data storage with parallel access and high throughput. Several methods exist for data multiplexing based on the fundamental principles of volume hologram selectivity. We recently demonstrated that a spatial (amplitude-phase) encoding of the reference wave (SERW) looks promising as a way to increase the storage density. The SERW hologram offers a method other than traditional methods of selectivity, such as spatial de-correlation between recorded and reconstruction fields, In this report we present the experimental results of the SERW-hologram memory module with solid-state architecture, which is of particular interest for space operations.

  11. Threshold-voltage modulated phase change heterojunction for application of high density memory

    International Nuclear Information System (INIS)

    Yan, Baihan; Tong, Hao; Qian, Hang; Miao, Xiangshui

    2015-01-01

    Phase change random access memory is one of the most important candidates for the next generation non-volatile memory technology. However, the ability to reduce its memory size is compromised by the fundamental limitations inherent in the CMOS technology. While 0T1R configuration without any additional access transistor shows great advantages in improving the storage density, the leakage current and small operation window limit its application in large-scale arrays. In this work, phase change heterojunction based on GeTe and n-Si is fabricated to address those problems. The relationship between threshold voltage and doping concentration is investigated, and energy band diagrams and X-ray photoelectron spectroscopy measurements are provided to explain the results. The threshold voltage is modulated to provide a large operational window based on this relationship. The switching performance of the heterojunction is also tested, showing a good reverse characteristic, which could effectively decrease the leakage current. Furthermore, a reliable read-write-erase function is achieved during the tests. Phase change heterojunction is proposed for high-density memory, showing some notable advantages, such as modulated threshold voltage, large operational window, and low leakage current

  12. Threshold-voltage modulated phase change heterojunction for application of high density memory

    Science.gov (United States)

    Yan, Baihan; Tong, Hao; Qian, Hang; Miao, Xiangshui

    2015-09-01

    Phase change random access memory is one of the most important candidates for the next generation non-volatile memory technology. However, the ability to reduce its memory size is compromised by the fundamental limitations inherent in the CMOS technology. While 0T1R configuration without any additional access transistor shows great advantages in improving the storage density, the leakage current and small operation window limit its application in large-scale arrays. In this work, phase change heterojunction based on GeTe and n-Si is fabricated to address those problems. The relationship between threshold voltage and doping concentration is investigated, and energy band diagrams and X-ray photoelectron spectroscopy measurements are provided to explain the results. The threshold voltage is modulated to provide a large operational window based on this relationship. The switching performance of the heterojunction is also tested, showing a good reverse characteristic, which could effectively decrease the leakage current. Furthermore, a reliable read-write-erase function is achieved during the tests. Phase change heterojunction is proposed for high-density memory, showing some notable advantages, such as modulated threshold voltage, large operational window, and low leakage current.

  13. Superconducting Multilayer High-Density Flexible Printed Circuit Board for Very High Thermal Resistance Interconnections

    Science.gov (United States)

    de la Broïse, Xavier; Le Coguie, Alain; Sauvageot, Jean-Luc; Pigot, Claude; Coppolani, Xavier; Moreau, Vincent; d'Hollosy, Samuel; Knarosovski, Timur; Engel, Andreas

    2018-05-01

    We have successively developed two superconducting flexible PCBs for cryogenic applications. The first one is monolayer, includes 552 tracks (10 µm wide, 20 µm spacing), and receives 24 wire-bonded integrated circuits. The second one is multilayer, with one track layer between two shielding layers interconnected by microvias, includes 37 tracks, and can be interconnected at both ends by wire bonding or by connectors. The first cold measurements have been performed and show good performances. The novelty of these products is, for the first one, the association of superconducting materials with very narrow pitch and bonded integrated circuits and, for the second one, the introduction of a superconducting multilayer structure interconnected by vias which is, to our knowledge, a world-first.

  14. Nanowire electrodes for high-density stimulation and measurement of neural circuits

    Directory of Open Access Journals (Sweden)

    Jacob T. Robinson

    2013-03-01

    Full Text Available Brain-machine interfaces (BMIs that can precisely monitor and control neural activity will likely require new hardware with improved resolution and specificity. New nanofabricated electrodes with feature sizes and densities comparable to neural circuits may lead to such improvements. In this perspective, we review the recent development of vertical nanowire (NW electrodes that could provide highly parallel single-cell recording and stimulation for future BMIs. We compare the advantages of these devices and discuss some of the technical challenges that must be overcome for this technology to become a platform for next-generation closed-loop BMIs.

  15. Design of two-terminal PNPN diode for high-density and high-speed memory applications

    International Nuclear Information System (INIS)

    Tong Xiaodong; Wu Hao; Liang Qingqing; Zhong Huicai; Zhu Huilong; Zhao Chao; Ye Tianchun

    2014-01-01

    A vertical two-terminal silicon PNPN diode is presented for use in a high-density memory cell. The device design for high-speed operations was studied with experiments and calibrated simulations, which proves that the proposed memory cell can be operated at nanosecond range. The static and dynamic power dissipations were also studied, which indicated the availability of the proposed memory cell for VLSI applications. Moreover, the memory cell is compatible with CMOS process, has little impact from process variation, and has good reliability. (semiconductor devices)

  16. High frequency P(VDF-TrFE) copolymer broadband annular array ultrasound transducers using high density flexible circuit interconnect

    Science.gov (United States)

    Gottlieb, Emanuel J.; Cannata, Jonathan M.; Hu, Chang Hong; Shung, K. K.

    2005-04-01

    A kerfless eight element high frequency ultrasound annular array transducer using 9 μm P(VDF-TrFE) bonded to a high density flexible interconnect was fabricated. The flexible circuit composed of Kapton polyimide film with gold electrode pattern of equal area annuli apertures on the top side of a 50 μm thick Kapton polyimide film. Each element had several 30 μm diameter electroplated vias that connected to electrode traces on the bottom side of the Kapton polyimide film. There was a 30 μm spacing between elements. The total aperture of the array was 3.12 mm. The transducer's performance has been modeled by implementing the Redwood version of the Mason model into PSpice and using the Krimholtz, Leedom and Matthaei (KLM) model utilized in the commercial software PiezoCAD. The transducer"s performance was evaluated by measuring the electrical impedance with a HP 4194 impedance analyzer, pulse echo response using a Panametrics 5900 pulser/receiver and crosstalk measurement for each element in the array. The measured electrical impedance for each element was 540 Ω and -84° phase. In order to improve device sensitivity an inductor was attached in series with each element to reduce the insertion loss to 33 dB. The measured average center frequency and bandwidth of each element was 55 MHz and 50% respectively. The measured crosstalk at the center frequency was -45 dB in water.

  17. A stacked memory device on logic 3D technology for ultra-high-density data storage

    International Nuclear Information System (INIS)

    Kim, Jiyoung; Hong, Augustin J; Kim, Sung Min; Shin, Kyeong-Sik; Song, Emil B; Hwang, Yongha; Xiu, Faxian; Galatsis, Kosmas; Chui, Chi On; Candler, Rob N; Wang, Kang L; Choi, Siyoung; Moon, Joo-Tae

    2011-01-01

    We have demonstrated, for the first time, a novel three-dimensional (3D) memory chip architecture of stacked-memory-devices-on-logic (SMOL) achieving up to 95% of cell-area efficiency by directly building up memory devices on top of front-end CMOS devices. In order to realize the SMOL, a unique 3D Flash memory device and vertical integration structure have been successfully developed. The SMOL architecture has great potential to achieve tera-bit level memory density by stacking memory devices vertically and maximizing cell-area efficiency. Furthermore, various emerging devices could replace the 3D memory device to develop new 3D chip architectures.

  18. A stacked memory device on logic 3D technology for ultra-high-density data storage

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jiyoung; Hong, Augustin J; Kim, Sung Min; Shin, Kyeong-Sik; Song, Emil B; Hwang, Yongha; Xiu, Faxian; Galatsis, Kosmas; Chui, Chi On; Candler, Rob N; Wang, Kang L [Device Research Laboratory, Department of Electrical Engineering, University of California, Los Angeles, CA 90095 (United States); Choi, Siyoung; Moon, Joo-Tae, E-mail: hbt100@ee.ucla.edu [Advanced Technology Development Team and Process Development Team, Memory R and D Center, Samsung Electronics Co. Ltd (Korea, Republic of)

    2011-06-24

    We have demonstrated, for the first time, a novel three-dimensional (3D) memory chip architecture of stacked-memory-devices-on-logic (SMOL) achieving up to 95% of cell-area efficiency by directly building up memory devices on top of front-end CMOS devices. In order to realize the SMOL, a unique 3D Flash memory device and vertical integration structure have been successfully developed. The SMOL architecture has great potential to achieve tera-bit level memory density by stacking memory devices vertically and maximizing cell-area efficiency. Furthermore, various emerging devices could replace the 3D memory device to develop new 3D chip architectures.

  19. Novel circuits for radiation hardened memories

    International Nuclear Information System (INIS)

    Haraszti, T.P.; Mento, R.P.; Moyer, N.E.; Grant, W.M.

    1992-01-01

    This paper reports on implementation of large storage semiconductor memories which combine radiation hardness with high packing density, operational speed, and low power dissipation and require both hardened circuit and hardened process technologies. Novel circuits, including orthogonal shuffle type of write-read arrays, error correction by weighted bidirectional codes and associative iterative repair circuits, are proposed for significant improvements of SRAMs' immunity against the effects of total dose and cosmic particle impacts. The implementation of the proposed circuit resulted in fault-tolerant 40-Mbit and 10-Mbit monolithic memories featuring a data rate of 120 MHz and power dissipation of 880 mW. These experimental serial-parallel memories were fabricated with a nonhardened standard CMOS processing technology, yet provided a total dose hardness of 1 Mrad and a projected SEU rate of 1 x 10 - 12 error/bit/day. Using radiation hardened processing improvements by factors of 10 to 100 are predicted in both total dose hardness and SEU rate

  20. The Corticohippocampal Circuit, Synaptic Plasticity, and Memory

    Science.gov (United States)

    Basu, Jayeeta; Siegelbaum, Steven A.

    2015-01-01

    Synaptic plasticity serves as a cellular substrate for information storage in the central nervous system. The entorhinal cortex (EC) and hippocampus are interconnected brain areas supporting basic cognitive functions important for the formation and retrieval of declarative memories. Here, we discuss how information flow in the EC–hippocampal loop is organized through circuit design. We highlight recently identified corticohippocampal and intrahippocampal connections and how these long-range and local microcircuits contribute to learning. This review also describes various forms of activity-dependent mechanisms that change the strength of corticohippocampal synaptic transmission. A key point to emerge from these studies is that patterned activity and interaction of coincident inputs gives rise to associational plasticity and long-term regulation of information flow. Finally, we offer insights about how learning-related synaptic plasticity within the corticohippocampal circuit during sensory experiences may enable adaptive behaviors for encoding spatial, episodic, social, and contextual memories. PMID:26525152

  1. A PD-SOI based DTI-LOCOS combined cross isolation technique for minimizing TID radiation induced leakage in high density memory

    International Nuclear Information System (INIS)

    Qiao Fengying; Pan Liyang; Wu Dong; Liu Lifang; Xu Jun

    2014-01-01

    In order to minimize leakage current increase under total ionizing dose (TID) radiation in high density memory circuits, a new isolation technique, combining deep trench isolation (DTI) between the wells, local oxidation of silicon (LOCOS) isolation between the devices within the well, and a P-diffused area in order to limit leakage at the isolation edge is implemented in partly-depleted silicon-on-insulator (PD-SOI) technology. This radiation hardening technique can minimize the layout area by more than 60%, and allows flexible placement of the body contact. Radiation hardened transistors and 256 Kb flash memory chips are designed and fabricated in a 0.6 μm PD-SOI process. Experiments show that no obvious increase in leakage current is observed for single transistors under 1 Mrad(Si) radiation, and that the 256 Kb memory chip still functions well after a TID of 100 krad(Si), with only 50% increase of the active power consumption in read mode. (semiconductor devices)

  2. Multilevel SOT-MRAM Cell with a Novel Sensing Scheme for High-Density Memory Applications

    DEFF Research Database (Denmark)

    Zeinali, Behzad; Esmaeili, Mahsa; Madsen, Jens Kargaard

    2017-01-01

    This paper presents a multilevel spin-orbit torque magnetic random access memory (SOT-MRAM). The conventional SOT-MRAMs enables a reliable and energy efficient write operation. However, these cells require two access transistors per cell, hence the efficiency of the SOTMRAMs can be questioned in ...

  3. Drosophila olfactory memory: single genes to complex neural circuits.

    Science.gov (United States)

    Keene, Alex C; Waddell, Scott

    2007-05-01

    A central goal of neuroscience is to understand how neural circuits encode memory and guide behaviour. Studying simple, genetically tractable organisms, such as Drosophila melanogaster, can illuminate principles of neural circuit organization and function. Early genetic dissection of D. melanogaster olfactory memory focused on individual genes and molecules. These molecular tags subsequently revealed key neural circuits for memory. Recent advances in genetic technology have allowed us to manipulate and observe activity in these circuits, and even individual neurons, in live animals. The studies have transformed D. melanogaster from a useful organism for gene discovery to an ideal model to understand neural circuit function in memory.

  4. Current Controlled Magnetization Switching in Cylindrical Nanowires for High-Density 3D Memory Applications

    KAUST Repository

    Mohammed, Hanan

    2018-04-18

    A next-generation memory device utilizing a three-dimensional nanowire system requires the reliable control of domain wall motion. In this letter, domain walls are studied in cylindrical nanowires consisting of alternating segments of cobalt and nickel. The material interfaces acting as domain wall pinning sites, are utilized in combination with current pulses, to control the position of the domain wall, which is monitored using magnetoresistance measurements. Magnetic force microscopy results further confirm the occurrence of current assisted domain wall depinning. Data bits are therefore shifted along the nanowire by sequentially pinning and depinning a domain wall between successive interfaces, a requirement necessary for race-track type memory devices. We demonstrate that the direction, amplitude and duration of the applied current pulses determine the propagation of the domain wall across pinning sites. These results demonstrate a multi-bit cylindrical nanowire device, utilizing current assisted data manipulation. The prospect of sequential pinning and depinning in these nanowires allows the bit density to increase by several Tbs, depending on the number of segments within these nanowires.

  5. Current Controlled Magnetization Switching in Cylindrical Nanowires for High-Density 3D Memory Applications

    KAUST Repository

    Mohammed, Hanan; Corte-Leó n, Hector; Ivanov, Yurii P.; Lopatin, Sergei; Moreno, Julian A.; Chuvilin, Andrey; Salimath, Akshaykumar; Manchon, Aurelien; Kazakova, Olga; Kosel, Jü rgen

    2018-01-01

    A next-generation memory device utilizing a three-dimensional nanowire system requires the reliable control of domain wall motion. In this letter, domain walls are studied in cylindrical nanowires consisting of alternating segments of cobalt and nickel. The material interfaces acting as domain wall pinning sites, are utilized in combination with current pulses, to control the position of the domain wall, which is monitored using magnetoresistance measurements. Magnetic force microscopy results further confirm the occurrence of current assisted domain wall depinning. Data bits are therefore shifted along the nanowire by sequentially pinning and depinning a domain wall between successive interfaces, a requirement necessary for race-track type memory devices. We demonstrate that the direction, amplitude and duration of the applied current pulses determine the propagation of the domain wall across pinning sites. These results demonstrate a multi-bit cylindrical nanowire device, utilizing current assisted data manipulation. The prospect of sequential pinning and depinning in these nanowires allows the bit density to increase by several Tbs, depending on the number of segments within these nanowires.

  6. Adaptation in human somatosensory cortex as a model of sensory memory construction: a study using high-density EEG.

    Science.gov (United States)

    Bradley, Claire; Joyce, Niamh; Garcia-Larrea, Luis

    2016-01-01

    Adaptation in sensory cortices has been seen as a mechanism allowing the creation of transient memory representations. Here we tested the adapting properties of early responses in human somatosensory areas SI and SII by analysing somatosensory-evoked potentials over the very first repetitions of a stimulus. SI and SII generators were identified by well-defined scalp potentials and source localisation from high-density 128-channel EEG. Earliest responses (~20 ms) from area 3b in the depth of the post-central gyrus did not show significant adaptation to stimuli repeated at 300 ms intervals. In contrast, responses around 45 ms from the crown of the gyrus (areas 1 and 2) rapidly lessened to a plateau and abated at the 20th stimulation, and activities from SII in the parietal operculum at ~100 ms displayed strong adaptation with a steady amplitude decrease from the first repetition. Although responses in both SI (1-2) and SII areas showed adapting properties and hence sensory memory capacities, evidence of sensory mismatch detection has been demonstrated only for responses reflecting SII activation. This may index the passage from an early form of sensory storage in SI to more operational memory codes in SII, allowing the prediction of forthcoming input and the triggering of a specific signal when such input differs from the previous sequence. This is consistent with a model whereby the length of temporal receptive windows increases with progression in the cortical hierarchy, in parallel with the complexity and abstraction of neural representations.

  7. Radiation effect test on ADC/DAC and high density memory devices with 60Co γ-rays

    International Nuclear Information System (INIS)

    Xing Kefei; Wang Yueke; Pan Huafeng

    2006-01-01

    A test platform was constructed for 60 Co γ-ray irradiation experiment of microelectronics, with the aid of computer and a FPGA module. The tested sample devices included analog-to-digital converter AD10465, digital-to-analog converter AD9857, high density Flash memory MEF64M16 and anti-fused PROM XQR17V16, which are used in signal processing module in spaceborne systems. Evaluations were made on their ability of resisting the total dose based on the proper function criterion of the devices. The results showed that AD10465 and AD9857 ran properly after 1.59 kGy(Si) irradiation, but errors were found when MEF64M16 and XQR17V16's total ionizing dose is 0.13 kGy(Si) and 0.99 kGy(Si), respectively. (authors)

  8. Integration of SrBi2Ta2O9 thin films for high density ferroelectric random access memory

    Science.gov (United States)

    Wouters, D. J.; Maes, D.; Goux, L.; Lisoni, J. G.; Paraschiv, V.; Johnson, J. A.; Schwitters, M.; Everaert, J.-L.; Boullart, W.; Schaekers, M.; Willegems, M.; Vander Meeren, H.; Haspeslagh, L.; Artoni, C.; Caputa, C.; Casella, P.; Corallo, G.; Russo, G.; Zambrano, R.; Monchoix, H.; Vecchio, G.; Van Autryve, L.

    2006-09-01

    Ferroelectric random access memory (FeRAM) is an attractive candidate technology for embedded nonvolatile memory, especially in applications where low power and high program speed are important. Market introduction of high-density FeRAM is, however, lagging behind standard complementary metal-oxide semiconductor (CMOS) because of the difficult integration technology. This paper discusses the major integration issues for high-density FeRAM, based on SrBi2Ta2O9 (strontium bismuth tantalate or SBT), in relation to the fabrication of our stacked cell structure. We have worked in the previous years on the development of SBT-FeRAM integration technology, based on a so-called pseudo-three-dimensional (3D) cell, with a capacitor that can be scaled from quasi two-dimensional towards a true three-dimensional capacitor where the sidewalls will importantly contribute to the signal. In the first phase of our integration development, we integrated our FeRAM cell in a 0.35μm CMOS technology. In a second phase, then, possibility of scaling of our cell is demonstrated in 0.18μm technology. The excellent electrical and reliability properties of the small integrated ferroelectric capacitors prove the feasibility of the technology, while the verification of the potential 3D effect confirms the basic scaling potential of our concept beyond that of the single-mask capacitor. The paper outlines the different material and technological challenges, and working solutions are demonstrated. While some issues are specific to our own cell, many are applicable to different stacked FeRAM cell concepts, or will become more general concerns when more developments are moving into 3D structures.

  9. Micro- and nano-scale optical devices for high density photonic integrated circuits at near-infrared wavelengths

    Science.gov (United States)

    Chatterjee, Rohit

    In this research work, we explore fundamental silicon-based active and passive photonic devices that can be integrated together to form functional photonic integrated circuits. The devices which include power splitters, switches and lenses are studied starting from their physics, their design and fabrication techniques and finally from an experimental standpoint. The experimental results reveal high performance devices that are compatible with standard CMOS fabrication processes and can be easily integrated with other devices for near infrared telecom applications. In Chapter 2, a novel method for optical switching using nanomechanical proximity perturbation technique is described and demonstrated. The method which is experimentally demonstrated employs relatively low powers, small chip footprint and is compatible with standard CMOS fabrication processes. Further, in Chapter 3, this method is applied to develop a hitless bypass switch aimed at solving an important issue in current wavelength division multiplexing systems namely hitless switching of reconfigurable optical add drop multiplexers. Experimental results are presented to demonstrate the application of the nanomechanical proximity perturbation technique to practical situations. In Chapter 4, a fundamental photonic component namely the power splitter is described. Power splitters are important components for any photonic integrated circuits because they help split the power from a single light source to multiple devices on the same chip so that different operations can be performed simultaneously. The power splitters demonstrated in this chapter are based on multimode interference principles resulting in highly compact low loss and highly uniform power splitting to split the power of the light from a single channel to two and four channels. These devices can further be scaled to achieve higher order splitting such as 1x16 and 1x32 power splits. Finally in Chapter 5 we overcome challenges in device

  10. MOSFET analog memory circuit achieves long duration signal storage

    Science.gov (United States)

    1966-01-01

    Memory circuit maintains the signal voltage at the output of an analog signal amplifier when the input signal is interrupted or removed. The circuit uses MOSFET /Metal Oxide Semiconductor Field Effect Transistor/ devices as voltage-controlled switches, triggered by an external voltage-sensing device.

  11. Neural circuits in auditory and audiovisual memory.

    Science.gov (United States)

    Plakke, B; Romanski, L M

    2016-06-01

    Working memory is the ability to employ recently seen or heard stimuli and apply them to changing cognitive context. Although much is known about language processing and visual working memory, the neurobiological basis of auditory working memory is less clear. Historically, part of the problem has been the difficulty in obtaining a robust animal model to study auditory short-term memory. In recent years there has been neurophysiological and lesion studies indicating a cortical network involving both temporal and frontal cortices. Studies specifically targeting the role of the prefrontal cortex (PFC) in auditory working memory have suggested that dorsal and ventral prefrontal regions perform different roles during the processing of auditory mnemonic information, with the dorsolateral PFC performing similar functions for both auditory and visual working memory. In contrast, the ventrolateral PFC (VLPFC), which contains cells that respond robustly to auditory stimuli and that process both face and vocal stimuli may be an essential locus for both auditory and audiovisual working memory. These findings suggest a critical role for the VLPFC in the processing, integrating, and retaining of communication information. This article is part of a Special Issue entitled SI: Auditory working memory. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. A diagonal address generator for a Josephson memory circuit

    International Nuclear Information System (INIS)

    Suzuki, H.; Hasuo, S.

    1987-01-01

    The authors propose that a diagonal D address generator, which is useful for a single flux quantum (SFQ) memory cell in the triple coincidence scheme, can be performed by a full adder circuit. For the purpose of evaluating the D address generator for a 16-kbit memory circuit, a 6-bit full adder circuit, using a current-steering flip-flop circuit, has been designed and fabricated with the lead-alloy process. Operating times for the address latch, carry generator, and sum generator were 150 ps, 250 ps/stage, and 1.4 ns, respectively. From these results, they estimate that the time necessary for the diagonal signal generation is 2.8 ns

  13. Memory and cognitive control circuits in mathematical cognition and learning.

    Science.gov (United States)

    Menon, V

    2016-01-01

    Numerical cognition relies on interactions within and between multiple functional brain systems, including those subserving quantity processing, working memory, declarative memory, and cognitive control. This chapter describes recent advances in our understanding of memory and control circuits in mathematical cognition and learning. The working memory system involves multiple parietal-frontal circuits which create short-term representations that allow manipulation of discrete quantities over several seconds. In contrast, hippocampal-frontal circuits underlying the declarative memory system play an important role in formation of associative memories and binding of new and old information, leading to the formation of long-term memories that allow generalization beyond individual problem attributes. The flow of information across these systems is regulated by flexible cognitive control systems which facilitate the integration and manipulation of quantity and mnemonic information. The implications of recent research for formulating a more comprehensive systems neuroscience view of the neural basis of mathematical learning and knowledge acquisition in both children and adults are discussed. © 2016 Elsevier B.V. All rights reserved.

  14. Memory and cognitive control circuits in mathematical cognition and learning

    Science.gov (United States)

    Menon, V.

    2018-01-01

    Numerical cognition relies on interactions within and between multiple functional brain systems, including those subserving quantity processing, working memory, declarative memory, and cognitive control. This chapter describes recent advances in our understanding of memory and control circuits in mathematical cognition and learning. The working memory system involves multiple parietal–frontal circuits which create short-term representations that allow manipulation of discrete quantities over several seconds. In contrast, hippocampal–frontal circuits underlying the declarative memory system play an important role in formation of associative memories and binding of new and old information, leading to the formation of long-term memories that allow generalization beyond individual problem attributes. The flow of information across these systems is regulated by flexible cognitive control systems which facilitate the integration and manipulation of quantity and mnemonic information. The implications of recent research for formulating a more comprehensive systems neuroscience view of the neural basis of mathematical learning and knowledge acquisition in both children and adults are discussed. PMID:27339012

  15. Chemical mechanical polishing of BTO thin film for vertical sidewall patterning of high-density memory capacitor

    International Nuclear Information System (INIS)

    Kim, Nam-Hoon; Ko, Pil-Ju; Seo, Yong-Jin; Lee, Woo-Sun

    2006-01-01

    Most high-k materials cannot to be etched easily. Problems such as low etch rate, poor sidewall angle, plasma damage, and process complexity have emerged in high-density DRAM fabrication. Chemical mechanical polishing (CMP) by the damascene process has been used to pattern high-k materials for high-density capacitor. Barium titanate (BTO) thin film, a typical high-k material, was polished with three types of silica slurry having different pH values. Sufficient removal rate with adequate selectivity to realize the pattern mask of tetra-ethyl ortho-silicate (TEOS) film for the vertical sidewall angle was obtained. The changes of X-ray diffraction pattern and dielectric constant by CMP process were negligible. Planarization was also achieved for the subsequent multilevel processes. Our new CMP approach will provide a guideline for effective patterning of high-k materials by CMP

  16. Emergence of task-dependent representations in working memory circuits

    Directory of Open Access Journals (Sweden)

    Cristina eSavin

    2014-05-01

    Full Text Available A wealth of experimental evidence suggests that working memory circuits preferentially represent information that is behaviorally relevant. Still, we are missing a mechanistic account of how these representations come about. Here we provide a simple explanation for a range of experimental findings, in light of prefrontal circuits adapting to task constraints by reward-dependent learning. In particular, we model a neural network shaped by reward-modulated spike-timing dependent plasticity (r-STDP and homeostatic plasticity (intrinsic excitability and synaptic scaling. We show that the experimentally-observed neural representations naturally emerge in an initially unstructured circuit as it learns to solve several working memory tasks. These results point to a critical, and previously unappreciated, role for reward-dependent learning in shaping prefrontal cortex activity.

  17. High-Density Lipoprotein Cholesterol Level Relates to Working Memory, Immediate and Delayed Cued Recall in Brazilian Older Adults: The Role of Cognitive Reserve.

    Science.gov (United States)

    Ihle, Andreas; Gouveia, Élvio R; Gouveia, Bruna R; Freitas, Duarte L; Jurema, Jefferson; Tinôco, Maria A; Kliegel, Matthias

    2017-01-01

    The present study set out to investigate the relation of the high-density lipoprotein cholesterol (HDL-C) level to cognitive performance and its interplay with key markers of cognitive reserve in a large sample of older adults. We assessed tests of working memory, immediate and delayed cued recall in 701 older adults from Amazonas, Brazil. The HDL-C level was derived from fasting blood samples. In addition, we interviewed individuals on their education, past occupation, and cognitive leisure activity. A critically low HDL-C level (cued recall. Moderation analyses suggested that the relations of the HDL-C level to working memory and delayed cued recall were negligible in individuals with longer education, a higher cognitive level of the job, and greater engagement in cognitive leisure activity. Cognitive reserve accumulated during the life course may reduce the detrimental influences of a critically low HDL-C level on cognitive functioning in old age. © 2017 S. Karger AG, Basel.

  18. Assessing the Driver's Current Level of Working Memory Load with High Density Functional Near-infrared Spectroscopy: A Realistic Driving Simulator Study.

    Science.gov (United States)

    Unni, Anirudh; Ihme, Klas; Jipp, Meike; Rieger, Jochem W

    2017-01-01

    Cognitive overload or underload results in a decrease in human performance which may result in fatal incidents while driving. We envision that driver assistive systems which adapt their functionality to the driver's cognitive state could be a promising approach to reduce road accidents due to human errors. This research attempts to predict variations of cognitive working memory load levels in a natural driving scenario with multiple parallel tasks and to reveal predictive brain areas. We used a modified version of the n-back task to induce five different working memory load levels (from 0-back up to 4-back) forcing the participants to continuously update, memorize, and recall the previous 'n' speed sequences and adjust their speed accordingly while they drove for approximately 60 min on a highway with concurrent traffic in a virtual reality driving simulator. We measured brain activation using multichannel whole head, high density functional near-infrared spectroscopy (fNIRS) and predicted working memory load level from the fNIRS data by combining multivariate lasso regression and cross-validation. This allowed us to predict variations in working memory load in a continuous time-resolved manner with mean Pearson correlations between induced and predicted working memory load over 15 participants of 0.61 [standard error (SE) 0.04] and a maximum of 0.8. Restricting the analysis to prefrontal sensors placed over the forehead reduced the mean correlation to 0.38 (SE 0.04), indicating additional information gained through whole head coverage. Moreover, working memory load predictions derived from peripheral heart rate parameters achieved much lower correlations (mean 0.21, SE 0.1). Importantly, whole head fNIRS sampling revealed increasing brain activation in bilateral inferior frontal and bilateral temporo-occipital brain areas with increasing working memory load levels suggesting that these areas are specifically involved in workload-related processing.

  19. Assessing the Driver’s Current Level of Working Memory Load with High Density Functional Near-infrared Spectroscopy: A Realistic Driving Simulator Study

    Science.gov (United States)

    Unni, Anirudh; Ihme, Klas; Jipp, Meike; Rieger, Jochem W.

    2017-01-01

    Cognitive overload or underload results in a decrease in human performance which may result in fatal incidents while driving. We envision that driver assistive systems which adapt their functionality to the driver’s cognitive state could be a promising approach to reduce road accidents due to human errors. This research attempts to predict variations of cognitive working memory load levels in a natural driving scenario with multiple parallel tasks and to reveal predictive brain areas. We used a modified version of the n-back task to induce five different working memory load levels (from 0-back up to 4-back) forcing the participants to continuously update, memorize, and recall the previous ‘n’ speed sequences and adjust their speed accordingly while they drove for approximately 60 min on a highway with concurrent traffic in a virtual reality driving simulator. We measured brain activation using multichannel whole head, high density functional near-infrared spectroscopy (fNIRS) and predicted working memory load level from the fNIRS data by combining multivariate lasso regression and cross-validation. This allowed us to predict variations in working memory load in a continuous time-resolved manner with mean Pearson correlations between induced and predicted working memory load over 15 participants of 0.61 [standard error (SE) 0.04] and a maximum of 0.8. Restricting the analysis to prefrontal sensors placed over the forehead reduced the mean correlation to 0.38 (SE 0.04), indicating additional information gained through whole head coverage. Moreover, working memory load predictions derived from peripheral heart rate parameters achieved much lower correlations (mean 0.21, SE 0.1). Importantly, whole head fNIRS sampling revealed increasing brain activation in bilateral inferior frontal and bilateral temporo-occipital brain areas with increasing working memory load levels suggesting that these areas are specifically involved in workload-related processing. PMID

  20. Assessing the Driver’s Current Level of Working Memory Load with High Density Functional Near-infrared Spectroscopy: A Realistic Driving Simulator Study

    Directory of Open Access Journals (Sweden)

    Anirudh Unni

    2017-04-01

    Full Text Available Cognitive overload or underload results in a decrease in human performance which may result in fatal incidents while driving. We envision that driver assistive systems which adapt their functionality to the driver’s cognitive state could be a promising approach to reduce road accidents due to human errors. This research attempts to predict variations of cognitive working memory load levels in a natural driving scenario with multiple parallel tasks and to reveal predictive brain areas. We used a modified version of the n-back task to induce five different working memory load levels (from 0-back up to 4-back forcing the participants to continuously update, memorize, and recall the previous ‘n’ speed sequences and adjust their speed accordingly while they drove for approximately 60 min on a highway with concurrent traffic in a virtual reality driving simulator. We measured brain activation using multichannel whole head, high density functional near-infrared spectroscopy (fNIRS and predicted working memory load level from the fNIRS data by combining multivariate lasso regression and cross-validation. This allowed us to predict variations in working memory load in a continuous time-resolved manner with mean Pearson correlations between induced and predicted working memory load over 15 participants of 0.61 [standard error (SE 0.04] and a maximum of 0.8. Restricting the analysis to prefrontal sensors placed over the forehead reduced the mean correlation to 0.38 (SE 0.04, indicating additional information gained through whole head coverage. Moreover, working memory load predictions derived from peripheral heart rate parameters achieved much lower correlations (mean 0.21, SE 0.1. Importantly, whole head fNIRS sampling revealed increasing brain activation in bilateral inferior frontal and bilateral temporo-occipital brain areas with increasing working memory load levels suggesting that these areas are specifically involved in workload

  1. A neuromorphic circuit mimicking biological short-term memory.

    Science.gov (United States)

    Barzegarjalali, Saeid; Parker, Alice C

    2016-08-01

    Research shows that the way we remember things for a few seconds is a different mechanism from the way we remember things for a longer time. Short-term memory is based on persistently firing neurons, whereas storing information for a longer time is based on strengthening the synapses or even forming new neural connections. Information about location and appearance of an object is segregated and processed by separate neurons. Furthermore neurons can continue firing using different mechanisms. Here, we have designed a biomimetic neuromorphic circuit that mimics short-term memory by firing neurons, using biological mechanisms to remember location and shape of an object. Our neuromorphic circuit has a hybrid architecture. Neurons are designed with CMOS 45nm technology and synapses are designed with carbon nanotubes (CNT).

  2. Circuit oscillations in odor perception and memory.

    Science.gov (United States)

    Kay, Leslie M

    2014-01-01

    Olfactory system neural oscillations as seen in the local field potential have been studied for many decades. Recent research has shown that there is a functional role for the most studied gamma oscillations (40-100Hz in rats and mice, and 20Hz in insects), without which fine odor discrimination is poor. When these oscillations are increased artificially, fine discrimination is increased, and when rats learn difficult and highly overlapping odor discriminations, gamma is increased in power. Because of the depth of study on this oscillation, it is possible to point to specific changes in neural firing patterns as represented by the increase in gamma oscillation amplitude. However, we know far less about the mechanisms governing beta oscillations (15-30Hz in rats and mice), which are best associated with associative learning of responses to odor stimuli. These oscillations engage every part of the olfactory system that has so far been tested, plus the hippocampus, and the beta oscillation frequency band is the one that is most reliably coherent with other regions during odor processing. Respiratory oscillations overlapping with the theta frequency band (2-12Hz) are associated with odor sniffing and normal breathing in rats. They also show coupling in some circumstances between olfactory areas and rare coupling between the hippocampus and olfactory bulb. The latter occur in specific learning conditions in which coherence strength is negatively or positively correlated with performance, depending on the task. There is still much to learn about the role of neural oscillations in learning and memory, but techniques that have been brought to bear on gamma oscillations (current source density, computational modeling, slice physiology, behavioral studies) should deliver much needed knowledge of these events. © 2014 Elsevier B.V. All rights reserved.

  3. Aging memory for pictures: using high-density event-related potentials to understand the effect of aging on the picture superiority effect.

    Science.gov (United States)

    Ally, Brandon A; Waring, Jill D; Beth, Ellen H; McKeever, Joshua D; Milberg, William P; Budson, Andrew E

    2008-01-31

    High-density event-related potentials (ERPs) were used to understand the effect of aging on the neural correlates of the picture superiority effect. Pictures and words were systematically varied at study and test while ERPs were recorded at retrieval. Here, the results of the word-word and picture-picture study-test conditions are presented. Behavioral results showed that older adults demonstrated the picture superiority effect to a greater extent than younger adults. The ERP data helped to explain these findings. The early frontal effect, parietal effect, and late frontal effect were all indistinguishable between older and younger adults for pictures. In contrast, for words, the early frontal and parietal effects were significantly diminished for the older adults compared to the younger adults. These two old/new effects have been linked to familiarity and recollection, respectively, and the authors speculate that these processes are impaired for word-based memory in the course of healthy aging. The findings of this study suggest that pictures allow older adults to compensate for their impaired memorial processes, and may allow these memorial components to function more effectively in older adults.

  4. Neural circuit mechanisms of short-term memory

    Science.gov (United States)

    Goldman, Mark

    Memory over time scales of seconds to tens of seconds is thought to be maintained by neural activity that is triggered by a memorized stimulus and persists long after the stimulus is turned off. This presents a challenge to current models of memory-storing mechanisms, because the typical time scales associated with cellular and synaptic dynamics are two orders of magnitude smaller than this. While such long time scales can easily be achieved by bistable processes that toggle like a flip-flop between a baseline and elevated-activity state, many neuronal systems have been observed experimentally to be capable of maintaining a continuum of stable states. For example, in neural integrator networks involved in the accumulation of evidence for decision making and in motor control, individual neurons have been recorded whose activity reflects the mathematical integral of their inputs; in the absence of input, these neurons sustain activity at a level proportional to the running total of their inputs. This represents an analog form of memory whose dynamics can be conceptualized through an energy landscape with a continuum of lowest-energy states. Such continuous attractor landscapes are structurally non-robust, in seeming violation of the relative robustness of biological memory systems. In this talk, I will present and compare different biologically motivated circuit motifs for the accumulation and storage of signals in short-term memory. Challenges to generating robust memory maintenance will be highlighted and potential mechanisms for ameliorating the sensitivity of memory networks to perturbations will be discussed. Funding for this work was provided by NIH R01 MH065034, NSF IIS-1208218, Simons Foundation 324260, and a UC Davis Ophthalmology Research to Prevent Blindness Grant.

  5. Updating Procedures Can Reorganize the Neural Circuit Supporting a Fear Memory.

    Science.gov (United States)

    Kwapis, Janine L; Jarome, Timothy J; Ferrara, Nicole C; Helmstetter, Fred J

    2017-07-01

    Established memories undergo a period of vulnerability following retrieval, a process termed 'reconsolidation.' Recent work has shown that the hypothetical process of reconsolidation is only triggered when new information is presented during retrieval, suggesting that this process may allow existing memories to be modified. Reconsolidation has received increasing attention as a possible therapeutic target for treating disorders that stem from traumatic memories, yet little is known about how this process changes the original memory. In particular, it is unknown whether reconsolidation can reorganize the neural circuit supporting an existing memory after that memory is modified with new information. Here, we show that trace fear memory undergoes a protein synthesis-dependent reconsolidation process following exposure to a single updating trial of delay conditioning. Further, this reconsolidation-dependent updating process appears to reorganize the neural circuit supporting the trace-trained memory, so that it better reflects the circuit supporting delay fear. Specifically, after a trace-to-delay update session, the amygdala is now required for extinction of the updated memory but the retrosplenial cortex is no longer required for retrieval. These results suggest that updating procedures could be used to force a complex, poorly defined memory circuit to rely on a better-defined neural circuit that may be more amenable to behavioral or pharmacological manipulation. This is the first evidence that exposure to new information can fundamentally reorganize the neural circuit supporting an existing memory.

  6. An innovative "ChemicalVia" process for the production of high density interconnect printed circuit boards The ATLAS muon chamber quality control with the X-ray tomograph at CERN

    CERN Document Server

    Da Silva, Vitor; Watts, David; Van der Bij, Erik; Banhidi, Z; Berbiers, Julien; Lampl, W; Marchesotti, M; Rangod, Stephane; Sbrissa, E; Schuh, S; Voss, Rüdiger; Zhuravlov, V

    2004-01-01

    The ChemicalVia process, patented by CERN, provides a new method of making microvias in high-density multilayer printed circuit boards of different types, such as sequential build-up (SBU), high density interconnected (HDI), or laminated multi-chip modules (MCM-L). The process uses chemical etching instead of laser, plasma or other etching techniques and can be implemented in a chain production line. This results in an overall reduced operation and maintenance cost and a much shorter hole production time as compared with other microvia processes. copy Emerald Group Publishing Limited. 4 Refs.4 An essential part of the Muon Spectrometer of the ATLAS experiment is based on the Monitored Drift Tube (MDT) technology. About 1200 muon drift chambers are being built at 13 institutes all over the world. The MDT chambers require an exceptional mechanical construction accuracy of better than 20 mu m. A dedicated X-ray tomograph has been developed at CERN since 1996 to control the mechanical quality of the chambers. The...

  7. Persistent activity in a recurrent circuit underlies courtship memory in Drosophila

    Science.gov (United States)

    Zhao, Xiaoliang; Lenek, Daniela; Dag, Ugur; Dickson, Barry J

    2018-01-01

    Recurrent connections are thought to be a common feature of the neural circuits that encode memories, but how memories are laid down in such circuits is not fully understood. Here we present evidence that courtship memory in Drosophila relies on the recurrent circuit between mushroom body gamma (MBγ), M6 output, and aSP13 dopaminergic neurons. We demonstrate persistent neuronal activity of aSP13 neurons and show that it transiently potentiates synaptic transmission from MBγ>M6 neurons. M6 neurons in turn provide input to aSP13 neurons, prolonging potentiation of MBγ>M6 synapses over time periods that match short-term memory. These data support a model in which persistent aSP13 activity within a recurrent circuit lays the foundation for a short-term memory. PMID:29322941

  8. Persistent activity in a recurrent circuit underlies courtship memory in Drosophila.

    Science.gov (United States)

    Zhao, Xiaoliang; Lenek, Daniela; Dag, Ugur; Dickson, Barry J; Keleman, Krystyna

    2018-01-11

    Recurrent connections are thought to be a common feature of the neural circuits that encode memories, but how memories are laid down in such circuits is not fully understood. Here we present evidence that courtship memory in Drosophila relies on the recurrent circuit between mushroom body gamma (MBγ), M6 output, and aSP13 dopaminergic neurons. We demonstrate persistent neuronal activity of aSP13 neurons and show that it transiently potentiates synaptic transmission from MBγ>M6 neurons. M6 neurons in turn provide input to aSP13 neurons, prolonging potentiation of MB γ >M6 synapses over time periods that match short-term memory. These data support a model in which persistent aSP13 activity within a recurrent circuit lays the foundation for a short-term memory. © 2018, Zhao et al.

  9. High density harp for SSCL linac

    International Nuclear Information System (INIS)

    Fritsche, C.T.; Krogh, M.L.; Crist, C.E.

    1993-01-01

    AlliedSignal Inc., Kansas City Division, and the Superconducting Super Collider Laboratory (SSCL) are collaboratively developing a high density harp for the SSCL linac. This harp is designed using hybrid microcircuit (HMC) technology to obtain a higher wire density than previously available. The developed harp contains one hundred twenty-eight 33-micron-diameter carbon wires on 0.38-mm centers. The harp features an onboard broken wire detection circuit. Carbon wire preparation and attachment processes were developed. High density surface mount connectors were located. The status of high density harp development will be presented along with planned future activities

  10. High density harp for SSCL linac

    International Nuclear Information System (INIS)

    Fritsche, C.T.; Krogh, M.L.

    1993-05-01

    AlliedSignal Inc., Kansas City Division, and the Superconducting Super Collider Laboratory (SSCL) are collaboratively developing a high density harp for the SSCL linac. This harp is designed using hybrid microcircuit (HMC) technology to obtain a higher wire density than previously available. The developed harp contains one hundred twenty-eight 33-micron-diameter carbon wires on 0.38-mm centers. The harp features an onboard broken wire detection circuit. Carbon wire preparation and attachment processes were developed. High density surface mount connectors were located. The status of high density harp development will be presented along with planned future activities

  11. MOSFET Switching Circuit Protects Shape Memory Alloy Actuators

    Science.gov (United States)

    Gummin, Mark A.

    2011-01-01

    A small-footprint, full surface-mount-component printed circuit board employs MOSFET (metal-oxide-semiconductor field-effect transistor) power switches to switch high currents from any input power supply from 3 to 30 V. High-force shape memory alloy (SMA) actuators generally require high current (up to 9 A at 28 V) to actuate. SMA wires (the driving element of the actuators) can be quickly overheated if power is not removed at the end of stroke, which can damage the wires. The new analog driver prevents overheating of the SMA wires in an actuator by momentarily removing power when the end limit switch is closed, thereby allowing complex control schemes to be adopted without concern for overheating. Either an integral pushbutton or microprocessor-controlled gate or control line inputs switch current to the actuator until the end switch line goes from logic high to logic low state. Power is then momentarily removed (switched off by the MOSFET). The analog driver is suited to use with nearly any SMA actuator.

  12. Circuit engineering principles for construction of bipolar large-scale integrated circuit storage devices and very large-scale main memory

    Science.gov (United States)

    Neklyudov, A. A.; Savenkov, V. N.; Sergeyez, A. G.

    1984-06-01

    Memories are improved by increasing speed or the memory volume on a single chip. The most effective means for increasing speeds in bipolar memories are current control circuits with the lowest extraction times for a specific power consumption (1/4 pJ/bit). The control current circuitry involves multistage current switches and circuits accelerating transient processes in storage elements and links. Circuit principles for the design of bipolar memories with maximum speeds for an assigned minimum of circuit topology are analyzed. Two main classes of storage with current control are considered: the ECL type and super-integrated injection type storage with data capacities of N = 1/4 and N 4/16, respectively. The circuits reduce logic voltage differentials and the volumes of lexical and discharge buses and control circuit buses. The limiting speed is determined by the antiinterference requirements of the memory in storage and extraction modes.

  13. A novel sourceline voltage compensation circuit for embedded NOR flash memory

    International Nuclear Information System (INIS)

    Zhang Shengbo; Yang Guangjun; Hu Jian; Xiao Jun

    2014-01-01

    A novel sourceline voltage compensation circuit for program operation in embedded flash memory is presented. With the sourceline voltage compensation circuit, the charge pump can modulate the output voltage according to the number of cells to be programmed with data “0”. So the IR drop on the sourceline decoding path is compensated, and a stable sourceline voltage can be obtained. In order to reduce the power dissipation in program operation, a bit-inversion program circuit is adopted. By using the bit-inversion program circuit, the cells programmed to data “0” are limited to half of the bits of a write data word, thus power dissipation in program operation is greatly reduced. A 1.8-V 8 × 64-kbits embedded NOR flash memory employing the two circuits has been integrated using a GSMC 0.18-μm 4-poly 4-metal CMOS process. (semiconductor integrated circuits)

  14. Grand Research Plan for Neural Circuits of Emotion and Memory--current status of neural circuit studies in China.

    Science.gov (United States)

    Zhu, Yuan-Gui; Cao, He-Qi; Dong, Er-Dan

    2013-02-01

    During recent years, major advances have been made in neuroscience, i.e., asynchronous release, three-dimensional structural data sets, saliency maps, magnesium in brain research, and new functional roles of long non-coding RNAs. Especially, the development of optogenetic technology provides access to important information about relevant neural circuits by allowing the activation of specific neurons in awake mammals and directly observing the resulting behavior. The Grand Research Plan for Neural Circuits of Emotion and Memory was launched by the National Natural Science Foundation of China. It takes emotion and memory as its main objects, making the best use of cutting-edge technologies from medical science, life science and information science. In this paper, we outline the current status of neural circuit studies in China and the technologies and methodologies being applied, as well as studies related to the impairments of emotion and memory. In this phase, we are making efforts to repair the current deficiencies by making adjustments, mainly involving four aspects of core scientific issues to investigate these circuits at multiple levels. Five research directions have been taken to solve important scientific problems while the Grand Research Plan is implemented. Future research into this area will be multimodal, incorporating a range of methods and sciences into each project. Addressing these issues will ensure a bright future, major discoveries, and a higher level of treatment for all affected by debilitating brain illnesses.

  15. Technology breakthroughs in high performance metal-oxide-semiconductor devices for ultra-high density, low power non-volatile memory applications

    Science.gov (United States)

    Hong, Augustin Jinwoo

    Non-volatile memory devices have attracted much attention because data can be retained without power consumption more than a decade. Therefore, non-volatile memory devices are essential to mobile electronic applications. Among state of the art non-volatile memory devices, NAND flash memory has earned the highest attention because of its ultra-high scalability and therefore its ultra-high storage capacity. However, human desire as well as market competition requires not only larger storage capacity but also lower power consumption for longer battery life time. One way to meet this human desire and extend the benefits of NAND flash memory is finding out new materials for storage layer inside the flash memory, which is called floating gate in the state of the art flash memory device. In this dissertation, we study new materials for the floating gate that can lower down the power consumption and increase the storage capacity at the same time. To this end, we employ various materials such as metal nanodot, metal thin film and graphene incorporating complementary-metal-oxide-semiconductor (CMOS) compatible processes. Experimental results show excellent memory effects at relatively low operating voltages. Detailed physics and analysis on experimental results are discussed. These new materials for data storage can be promising candidates for future non-volatile memory application beyond the state of the art flash technologies.

  16. Aging memory for pictures: Using high-density event-related potentials to understand the effect of aging on the picture superiority effect

    OpenAIRE

    Ally, Brandon A.; Waring, Jill D.; Beth, Ellen H.; McKeever, Joshua D.; Milberg, William P.; Budson, Andrew E.

    2007-01-01

    High-density event-related potentials (ERPs) were used to understand the effect of aging on the neural correlates of the picture superiority effect. Pictures and words were systematically varied at study and test while ERPs were recorded at retrieval. Here, the results of the word-word and picture-picture study-test conditions are presented. Behavioral results showed that older adults demonstrated the picture superiority effect to a greater extent than younger adults. The ERP data helped to e...

  17. Simulation of pulsed-ionizing-radiation-induced errors in CMOS memory circuits

    International Nuclear Information System (INIS)

    Massengill, L.W.

    1987-01-01

    Effects of transient ionizing radiation on complementary metal-oxide-semiconductor (CMOS) memory circuits was studied by computer simulation. Simulation results have uncovered the dominant mechanism leading to information loss (upset) in dense (CMOS) circuits: rail span collapse. This effect is the catastrophic reduction in the local power supply at a RAM cell location due to the conglomerate radiation-induced photocurrents from all other RAM cells flowing through the power-supply-interconnect distribution. Rail-span collapse leads to reduced RAM cell-noise margins and can predicate upset. Results show that rail-span collapse in the dominant pulsed radiation effect in many memory circuits, preempting local circuit responses to the radiation. Several techniques to model power-supply noise, such as that arising from rail span collapse, are presented in this work. These include an analytical model for design optimization against these effects, a hierarchical computer-analysis technique for efficient power bus noise simulation in arrayed circuits, such as memories, and a complete circuit-simulation tool for noise margin analysis of circuits with arbitrary topologies

  18. Chemically programmed ink-jet printed resistive WORM memory array and readout circuit

    International Nuclear Information System (INIS)

    Andersson, H; Manuilskiy, A; Sidén, J; Gao, J; Kunninmel, G V; Nilsson, H-E; Hummelgård, M

    2014-01-01

    In this paper an ink-jet printed write once read many (WORM) resistive memory fabricated on paper substrate is presented. The memory elements are programmed for different resistance states by printing triethylene glycol monoethyl ether on the substrate before the actual memory element is printed using silver nano particle ink. The resistance is thus able to be set to a broad range of values without changing the geometry of the elements. A memory card consisting of 16 elements is manufactured for which the elements are each programmed to one of four defined logic levels, providing a total of 4294 967 296 unique possible combinations. Using a readout circuit, originally developed for resistive sensors to avoid crosstalk between elements, a memory card reader is manufactured that is able to read the values of the memory card and transfer the data to a PC. Such printed memory cards can be used in various applications. (paper)

  19. Memory formation orchestrates the wiring of adult-born hippocampal neurons into brain circuits.

    Science.gov (United States)

    Petsophonsakul, Petnoi; Richetin, Kevin; Andraini, Trinovita; Roybon, Laurent; Rampon, Claire

    2017-08-01

    During memory formation, structural rearrangements of dendritic spines provide a mean to durably modulate synaptic connectivity within neuronal networks. New neurons generated throughout the adult life in the dentate gyrus of the hippocampus contribute to learning and memory. As these neurons become incorporated into the network, they generate huge numbers of new connections that modify hippocampal circuitry and functioning. However, it is yet unclear as to how the dynamic process of memory formation influences their synaptic integration into neuronal circuits. New memories are established according to a multistep process during which new information is first acquired and then consolidated to form a stable memory trace. Upon recall, memory is transiently destabilized and vulnerable to modification. Using contextual fear conditioning, we found that learning was associated with an acceleration of dendritic spines formation of adult-born neurons, and that spine connectivity becomes strengthened after memory consolidation. Moreover, we observed that afferent connectivity onto adult-born neurons is enhanced after memory retrieval, while extinction training induces a change of spine shapes. Together, these findings reveal that the neuronal activity supporting memory processes strongly influences the structural dendritic integration of adult-born neurons into pre-existing neuronal circuits. Such change of afferent connectivity is likely to impact the overall wiring of hippocampal network, and consequently, to regulate hippocampal function.

  20. High density dispersion fuel

    International Nuclear Information System (INIS)

    Hofman, G.L.

    1996-01-01

    A fuel development campaign that results in an aluminum plate-type fuel of unlimited LEU burnup capability with an uranium loading of 9 grams per cm 3 of meat should be considered an unqualified success. The current worldwide approved and accepted highest loading is 4.8 g cm -3 with U 3 Si 2 as fuel. High-density uranium compounds offer no real density advantage over U 3 Si 2 and have less desirable fabrication and performance characteristics as well. Of the higher-density compounds, U 3 Si has approximately a 30% higher uranium density but the density of the U 6 X compounds would yield the factor 1.5 needed to achieve 9 g cm -3 uranium loading. Unfortunately, irradiation tests proved these peritectic compounds have poor swelling behavior. It is for this reason that the authors are turning to uranium alloys. The reason pure uranium was not seriously considered as a dispersion fuel is mainly due to its high rate of growth and swelling at low temperatures. This problem was solved at least for relatively low burnup application in non-dispersion fuel elements with small additions of Si, Fe, and Al. This so called adjusted uranium has nearly the same density as pure α-uranium and it seems prudent to reconsider this alloy as a dispersant. Further modifications of uranium metal to achieve higher burnup swelling stability involve stabilization of the cubic γ phase at low temperatures where normally α phase exists. Several low neutron capture cross section elements such as Zr, Nb, Ti and Mo accomplish this in various degrees. The challenge is to produce a suitable form of fuel powder and develop a plate fabrication procedure, as well as obtain high burnup capability through irradiation testing

  1. Ontogeny of neural circuits underlying spatial memory in the rat

    Directory of Open Access Journals (Sweden)

    James Alexander Ainge

    2012-03-01

    Full Text Available Spatial memory is a well characterised psychological function in both humans and rodents. The combined computations of a network of systems including place cells in the hippocampus, grid cells in the medial entorhinal cortex and head direction cells found in numerous structures in the brain have been suggested to form the neural instantiation of the cognitive map as first described by Tolman in 1948. However, while our understanding of the neural mechanisms underlying spatial representations in adults is relatively sophisticated, we know substantially less about how this network develops in young animals. In this article we review studies examining the developmental timescale that these systems follow. Electrophysiological recordings from very young rats show that directional information is at adult levels at the outset of navigational experience. The systems supporting allocentric memory, however, take longer to mature. This is consistent with behavioural studies of young rats which show that spatial memory based on head direction develops very early but that allocentric spatial memory takes longer to mature. We go on to report new data demonstrating that memory for associations between objects and their spatial locations is slower to develop than memory for objects alone. This is again consistent with previous reports suggesting that adult like spatial representations have a protracted development in rats and also suggests that the systems involved in processing non-spatial stimuli come online earlier.

  2. Principle for possible memory structures with extra high density by using the electron sharing mechanisms of atoms in an inflective orbit

    Science.gov (United States)

    Sengor, T.

    2014-10-01

    Both of the qualitative and quantitative knowledge of electromagnetic fields in the inter-atomic scale bring useful applications. From this point of view, bringing some possible new sights and solutions to atom-electron-photon-atom and/or molecule interactions is aimed in the near-field at inter atomic scale and their potential applications. The electron sharing processes between neighbor atoms are considered as an inflective surface system and an inflective guiding processes. The critical pass and transition structures are derived. The structures involving trigging that transition mechanisms may be suitable to design extra high density and fast data storage processes. The electron sharing processes between two near atomic system are modelled with gate mechanisms involving two distinct passages: continuous pass and discontinuous pass. Even if the stochastic processes are applicable at these cases theoretical approach putting an influence like inner and external dipole mechanisms fits best to the situation and provides almost deterministic scheme, which has potential to estimate some processes being able to design new electronics structures and devices. We call orbitron all of such structures and/or devices. The boundary value problem of atomic system sharing an electron in the way of electron passage model is formulated in inflective spherical coordinate system. The wave phenomenon is studied near spherically inflection points. The analytical essentials are derived for the solution of Helmholtz's equation when inflective boundaries are included. The evaluation is obtained by the extracted separation method. The results are given by using the spherically inflective wave series. The method is reshaped for the solution of Schrödinger equation.

  3. Enhancement of a cyclic endurance of phase change memory by application of a high-density C15(Ge21Sb36Te43 film

    Directory of Open Access Journals (Sweden)

    J. H. Park

    2016-02-01

    Full Text Available The lower cyclic endurance of Phase Change Memory (PCM devices limits the spread of its applications for reliable memory. The findings reported here show that micro-voids and excess vacancies that are produced during the deposition process and the subsequent growth in sputtered carbon-doped GeSbTe films is one of the major causes of device failure in PCM with cycling. We found that the size of voids in C15(Ge21Sb36Te43 films increased with increasing annealing temperature and the activation energy for the growth rate of voids was determined to be 2.22 eV. The film density, which is closely related to voids, varies with the deposition temperature and sputtering power used. The lower heat of vaporization of elemental Sb and Te compared to that for elemental Ge and C is a major cause of the low density of the film. It was possible to suppress void formation to a considerable extent by optimizing the deposition conditions, which leads to a dramatic enhancement in cyclic endurance by 2 orders of magnitude in PCM devices prepared at 300oC-300W compared to one prepared at 240oC-500W without change of compositions.

  4. Using an Insect Mushroom Body Circuit to Encode Route Memory in Complex Natural Environments.

    Directory of Open Access Journals (Sweden)

    Paul Ardin

    2016-02-01

    Full Text Available Ants, like many other animals, use visual memory to follow extended routes through complex environments, but it is unknown how their small brains implement this capability. The mushroom body neuropils have been identified as a crucial memory circuit in the insect brain, but their function has mostly been explored for simple olfactory association tasks. We show that a spiking neural model of this circuit originally developed to describe fruitfly (Drosophila melanogaster olfactory association, can also account for the ability of desert ants (Cataglyphis velox to rapidly learn visual routes through complex natural environments. We further demonstrate that abstracting the key computational principles of this circuit, which include one-shot learning of sparse codes, enables the theoretical storage capacity of the ant mushroom body to be estimated at hundreds of independent images.

  5. Recent trends in hardware security exploiting hybrid CMOS-resistive memory circuits

    Science.gov (United States)

    Sahay, Shubham; Suri, Manan

    2017-12-01

    This paper provides a comprehensive review and insight of recent trends in the field of random number generator (RNG) and physically unclonable function (PUF) circuits implemented using different types of emerging resistive non-volatile (NVM) memory devices. We present a detailed review of hybrid RNG/PUF implementations based on the use of (i) Spin-Transfer Torque (STT-MRAM), and (ii) metal-oxide based (OxRAM), NVM devices. Various approaches on Hybrid CMOS-NVM RNG/PUF circuits are considered, followed by a discussion on different nanoscale device phenomena. Certain nanoscale device phenomena (variability/stochasticity etc), which are otherwise undesirable for reliable memory and storage applications, form the basis for low power and highly scalable RNG/PUF circuits. Detailed qualitative comparison and benchmarking of all implementations is performed.

  6. Application of source biasing technique for energy efficient DECODER circuit design: memory array application

    Science.gov (United States)

    Gupta, Neha; Parihar, Priyanka; Neema, Vaibhav

    2018-04-01

    Researchers have proposed many circuit techniques to reduce leakage power dissipation in memory cells. If we want to reduce the overall power in the memory system, we have to work on the input circuitry of memory architecture i.e. row and column decoder. In this research work, low leakage power with a high speed row and column decoder for memory array application is designed and four new techniques are proposed. In this work, the comparison of cluster DECODER, body bias DECODER, source bias DECODER, and source coupling DECODER are designed and analyzed for memory array application. Simulation is performed for the comparative analysis of different DECODER design parameters at 180 nm GPDK technology file using the CADENCE tool. Simulation results show that the proposed source bias DECODER circuit technique decreases the leakage current by 99.92% and static energy by 99.92% at a supply voltage of 1.2 V. The proposed circuit also improves dynamic power dissipation by 5.69%, dynamic PDP/EDP 65.03% and delay 57.25% at 1.2 V supply voltage.

  7. Silicon photonic integrated circuits with electrically programmable non-volatile memory functions.

    Science.gov (United States)

    Song, J-F; Lim, A E-J; Luo, X-S; Fang, Q; Li, C; Jia, L X; Tu, X-G; Huang, Y; Zhou, H-F; Liow, T-Y; Lo, G-Q

    2016-09-19

    Conventional silicon photonic integrated circuits do not normally possess memory functions, which require on-chip power in order to maintain circuit states in tuned or field-configured switching routes. In this context, we present an electrically programmable add/drop microring resonator with a wavelength shift of 426 pm between the ON/OFF states. Electrical pulses are used to control the choice of the state. Our experimental results show a wavelength shift of 2.8 pm/ms and a light intensity variation of ~0.12 dB/ms for a fixed wavelength in the OFF state. Theoretically, our device can accommodate up to 65 states of multi-level memory functions. Such memory functions can be integrated into wavelength division mutiplexing (WDM) filters and applied to optical routers and computing architectures fulfilling large data downloading demands.

  8. Brain injury impairs working memory and prefrontal circuit function

    Directory of Open Access Journals (Sweden)

    Colin James Smith

    2015-11-01

    Full Text Available More than 2.5 million Americans suffer a traumatic brain injury (TBI each year. Even mild to moderate traumatic brain injury causes long-lasting neurological effects. Despite its prevalence, no therapy currently exists to treat the underlying cause of cognitive impairment suffered by TBI patients. Following lateral fluid percussion injury (LFPI, the most widely used experimental model of TBI, we investigated alterations in working memory and excitatory/inhibitory synaptic balance in the prefrontal cortex. LFPI impaired working memory as assessed with a T-maze behavioral task. Field excitatory postsynaptic potentials recorded in the prefrontal cortex were reduced in slices derived from brain-injured mice. Spontaneous and miniature excitatory postsynaptic currents onto layer 2/3 neurons were more frequent in slices derived from LFPI mice while inhibitory currents onto layer 2/3 neurons were smaller after LFPI. Additionally, an increase in action potential threshold and concomitant decrease in firing rate was observed in layer 2/3 neurons in slices from injured animals. Conversely, no differences in excitatory or inhibitory synaptic transmission onto layer 5 neurons were observed; however, layer 5 neurons demonstrated a decrease in input resistance and action potential duration after LFPI. These results demonstrate synaptic and intrinsic alterations in prefrontal circuitry that may underlie working memory impairment caused by TBI.

  9. Two Independent Mushroom Body Output Circuits Retrieve the Six Discrete Components of Drosophila Aversive Memory

    Directory of Open Access Journals (Sweden)

    Emna Bouzaiane

    2015-05-01

    Full Text Available Understanding how the various memory components are encoded and how they interact to guide behavior requires knowledge of the underlying neural circuits. Currently, aversive olfactory memory in Drosophila is behaviorally subdivided into four discrete phases. Among these, short- and long-term memories rely, respectively, on the γ and α/β Kenyon cells (KCs, two distinct subsets of the ∼2,000 neurons in the mushroom body (MB. Whereas V2 efferent neurons retrieve memory from α/β KCs, the neurons that retrieve short-term memory are unknown. We identified a specific pair of MB efferent neurons, named M6, that retrieve memory from γ KCs. Moreover, our network analysis revealed that six discrete memory phases actually exist, three of which have been conflated in the past. At each time point, two distinct memory components separately recruit either V2 or M6 output pathways. Memory retrieval thus features a dramatic convergence from KCs to MB efferent neurons.

  10. Implementation of digital equality comparator circuit on memristive memory crossbar array using material implication logic

    Science.gov (United States)

    Haron, Adib; Mahdzair, Fazren; Luqman, Anas; Osman, Nazmie; Junid, Syed Abdul Mutalib Al

    2018-03-01

    One of the most significant constraints of Von Neumann architecture is the limited bandwidth between memory and processor. The cost to move data back and forth between memory and processor is considerably higher than the computation in the processor itself. This architecture significantly impacts the Big Data and data-intensive application such as DNA analysis comparison which spend most of the processing time to move data. Recently, the in-memory processing concept was proposed, which is based on the capability to perform the logic operation on the physical memory structure using a crossbar topology and non-volatile resistive-switching memristor technology. This paper proposes a scheme to map digital equality comparator circuit on memristive memory crossbar array. The 2-bit, 4-bit, 8-bit, 16-bit, 32-bit, and 64-bit of equality comparator circuit are mapped on memristive memory crossbar array by using material implication logic in a sequential and parallel method. The simulation results show that, for the 64-bit word size, the parallel mapping exhibits 2.8× better performance in total execution time than sequential mapping but has a trade-off in terms of energy consumption and area utilization. Meanwhile, the total crossbar area can be reduced by 1.2× for sequential mapping and 1.5× for parallel mapping both by using the overlapping technique.

  11. Effects of homeostatic constraints on associative memory storage and synaptic connectivity of cortical circuits

    Directory of Open Access Journals (Sweden)

    Julio eChapeton

    2015-06-01

    Full Text Available The impact of learning and long-term memory storage on synaptic connectivity is not completely understood. In this study, we examine the effects of associative learning on synaptic connectivity in adult cortical circuits by hypothesizing that these circuits function in a steady-state, in which the memory capacity of a circuit is maximal and learning must be accompanied by forgetting. Steady-state circuits should be characterized by unique connectivity features. To uncover such features we developed a biologically constrained, exactly solvable model of associative memory storage. The model is applicable to networks of multiple excitatory and inhibitory neuron classes and can account for homeostatic constraints on the number and the overall weight of functional connections received by each neuron. The results show that in spite of a large number of neuron classes, functional connections between potentially connected cells are realized with less than 50% probability if the presynaptic cell is excitatory and generally a much greater probability if it is inhibitory. We also find that constraining the overall weight of presynaptic connections leads to Gaussian connection weight distributions that are truncated at zero. In contrast, constraining the total number of functional presynaptic connections leads to non-Gaussian distributions, in which weak connections are absent. These theoretical predictions are compared with a large dataset of published experimental studies reporting amplitudes of unitary postsynaptic potentials and probabilities of connections between various classes of excitatory and inhibitory neurons in the cerebellum, neocortex, and hippocampus.

  12. Working Memory and Decision-Making in a Frontoparietal Circuit Model.

    Science.gov (United States)

    Murray, John D; Jaramillo, Jorge; Wang, Xiao-Jing

    2017-12-13

    Working memory (WM) and decision-making (DM) are fundamental cognitive functions involving a distributed interacting network of brain areas, with the posterior parietal cortex (PPC) and prefrontal cortex (PFC) at the core. However, the shared and distinct roles of these areas and the nature of their coordination in cognitive function remain poorly understood. Biophysically based computational models of cortical circuits have provided insights into the mechanisms supporting these functions, yet they have primarily focused on the local microcircuit level, raising questions about the principles for distributed cognitive computation in multiregional networks. To examine these issues, we developed a distributed circuit model of two reciprocally interacting modules representing PPC and PFC circuits. The circuit architecture includes hierarchical differences in local recurrent structure and implements reciprocal long-range projections. This parsimonious model captures a range of behavioral and neuronal features of frontoparietal circuits across multiple WM and DM paradigms. In the context of WM, both areas exhibit persistent activity, but, in response to intervening distractors, PPC transiently encodes distractors while PFC filters distractors and supports WM robustness. With regard to DM, the PPC module generates graded representations of accumulated evidence supporting target selection, while the PFC module generates more categorical responses related to action or choice. These findings suggest computational principles for distributed, hierarchical processing in cortex during cognitive function and provide a framework for extension to multiregional models. SIGNIFICANCE STATEMENT Working memory and decision-making are fundamental "building blocks" of cognition, and deficits in these functions are associated with neuropsychiatric disorders such as schizophrenia. These cognitive functions engage distributed networks with prefrontal cortex (PFC) and posterior parietal

  13. Circuit Analysis of a Drosophila Dopamine Type 2 Receptor That Supports Anesthesia-Resistant Memory.

    Science.gov (United States)

    Scholz-Kornehl, Sabrina; Schwärzel, Martin

    2016-07-27

    Dopamine is central to reinforcement processing and exerts this function in species ranging from humans to fruit flies. It can do so via two different types of receptors (i.e., D1 or D2) that mediate either augmentation or abatement of cellular cAMP levels. Whereas D1 receptors are known to contribute to Drosophila aversive odor learning per se, we here show that D2 receptors are specific for support of a consolidated form of odor memory known as anesthesia-resistant memory. By means of genetic mosaicism, we localize this function to Kenyon cells, the mushroom body intrinsic neurons, as well as GABAergic APL neurons and local interneurons of the antennal lobes, suggesting that consolidated anesthesia-resistant memory requires widespread dopaminergic modulation within the olfactory circuit. Additionally, dopaminergic neurons themselves require D2R, suggesting a critical role in dopamine release via its recognized autoreceptor function. Considering the dual role of dopamine in balancing memory acquisition (proactive function of dopamine) and its "forgetting" (retroactive function of dopamine), our analysis suggests D2R as central player of either process. Dopamine provides different information; while it mediates reinforcement during the learning act (proactive function), it balances memory performance between two antithetic processes thereafter (retroactive function) (i.e., forgetting and augmentation). Such bidirectional design can also be found at level of dopamine receptors, where augmenting D1 and abating D2 receptors are engaged to balance cellular cAMP levels. Here, we report that consolidated anesthesia-resistant memory (ARM), but not other concomitant memory phases, are sensitive to bidirectional dopaminergic signals. By means of genetic mosaicism, we identified widespread dopaminergic modulation within the olfactory circuit that suggests nonredundant and reiterating functions of D2R in support of ARM. Our results oppose ARM to its concomitant memory phases

  14. Beta irradiation as a method of the static MOS RAM memories processing and circuit design verification

    International Nuclear Information System (INIS)

    Wislowski, J.; Jagusztyn, M.

    1985-01-01

    1K NMOS RAM's in plastic packages were investigated after beta irradiation up to 100 Gy (Si) total dose. The memory samples differed as regards processing details and circuit design. Radioisotope beta sources were used for irradiation as the most safe and least expensive. A new version of the model of radiation-induced functional degradation of MOS RAM's has been proposed. 19 refs., 8 figs., 5 tabs. (author)

  15. Semantic memory retrieval circuit: role of pre-SMA, caudate, and thalamus.

    Science.gov (United States)

    Hart, John; Maguire, Mandy J; Motes, Michael; Mudar, Raksha Anand; Chiang, Hsueh-Sheng; Womack, Kyle B; Kraut, Michael A

    2013-07-01

    We propose that pre-supplementary motor area (pre-SMA)-thalamic interactions govern processes fundamental to semantic retrieval of an integrated object memory. At the onset of semantic retrieval, pre-SMA initiates electrical interactions between multiple cortical regions associated with semantic memory subsystems encodings as indexed by an increase in theta-band EEG power. This starts between 100-150 ms after stimulus presentation and is sustained throughout the task. We posit that this activity represents initiation of the object memory search, which continues in searching for an object memory. When the correct memory is retrieved, there is a high beta-band EEG power increase, which reflects communication between pre-SMA and thalamus, designates the end of the search process and resultant in object retrieval from multiple semantic memory subsystems. This high beta signal is also detected in cortical regions. This circuit is modulated by the caudate nuclei to facilitate correct and suppress incorrect target memories. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Selective alterations of neurons and circuits related to early memory loss in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    María eLlorens-Martín

    2014-05-01

    Full Text Available A progressive loss of episodic memory is a well-known clinical symptom that characterizes Alzheimer’s disease (AD. The beginning of this loss of memory has been associated with the very early, pathological accumulation of tau and neuronal degeneration observed in the entorhinal cortex (EC. Tau-related pathology is thought to then spread progressively to the hippocampal formation and other brain areas as the disease progresses. The major cortical afferent source of the hippocampus and dentate gyrus is the EC through the perforant pathway. At least two main circuits participate in the connection between EC and the hippocampus; one originating in layer II and the other in layer III of the EC giving rise to the classical trisynaptic (ECII→dentate gyrus→CA3→CA1 and monosynaptic (ECIII→CA1 circuits. Thus, the study of the early pathological changes in these circuits is of great interest. In this review, we will discuss mainly the alterations of the granule cell neurons of the dentate gyrus and the atrophy of CA1 pyramidal neurons that occur in AD in relation to the possible differential alterations of these two main circuits.

  17. Reward signal in a recurrent circuit drives appetitive long-term memory formation.

    Science.gov (United States)

    Ichinose, Toshiharu; Aso, Yoshinori; Yamagata, Nobuhiro; Abe, Ayako; Rubin, Gerald M; Tanimoto, Hiromu

    2015-11-17

    Dopamine signals reward in animal brains. A single presentation of a sugar reward to Drosophila activates distinct subsets of dopamine neurons that independently induce short- and long-term olfactory memories (STM and LTM, respectively). In this study, we show that a recurrent reward circuit underlies the formation and consolidation of LTM. This feedback circuit is composed of a single class of reward-signaling dopamine neurons (PAM-α1) projecting to a restricted region of the mushroom body (MB), and a specific MB output cell type, MBON-α1, whose dendrites arborize that same MB compartment. Both MBON-α1 and PAM-α1 neurons are required during the acquisition and consolidation of appetitive LTM. MBON-α1 additionally mediates the retrieval of LTM, which is dependent on the dopamine receptor signaling in the MB α/β neurons. Our results suggest that a reward signal transforms a nascent memory trace into a stable LTM using a feedback circuit at the cost of memory specificity.

  18. Hippocampal-medial prefrontal circuit supports memory updating during learning and post-encoding rest

    Science.gov (United States)

    Schlichting, Margaret L.; Preston, Alison R.

    2015-01-01

    Learning occurs in the context of existing memories. Encountering new information that relates to prior knowledge may trigger integration, whereby established memories are updated to incorporate new content. Here, we provide a critical test of recent theories suggesting hippocampal (HPC) and medial prefrontal (MPFC) involvement in integration, both during and immediately following encoding. Human participants with established memories for a set of initial (AB) associations underwent fMRI scanning during passive rest and encoding of new related (BC) and unrelated (XY) pairs. We show that HPC-MPFC functional coupling during learning was more predictive of trial-by-trial memory for associations related to prior knowledge relative to unrelated associations. Moreover, the degree to which HPC-MPFC functional coupling was enhanced following overlapping encoding was related to memory integration behavior across participants. We observed a dissociation between anterior and posterior MPFC, with integration signatures during post-encoding rest specifically in the posterior subregion. These results highlight the persistence of integration signatures into post-encoding periods, indicating continued processing of interrelated memories during rest. We also interrogated the coherence of white matter tracts to assess the hypothesis that integration behavior would be related to the integrity of the underlying anatomical pathways. Consistent with our predictions, more coherent HPC-MPFC white matter structure was associated with better performance across participants. This HPC-MPFC circuit also interacted with content-sensitive visual cortex during learning and rest, consistent with reinstatement of prior knowledge to enable updating. These results show that the HPC-MPFC circuit supports on- and offline integration of new content into memory. PMID:26608407

  19. Building hippocampal circuits to learn and remember: insights into the development of human memory.

    Science.gov (United States)

    Lavenex, Pierre; Banta Lavenex, Pamela

    2013-10-01

    The hippocampal formation is essential for the processing of episodic memories for autobiographical events that happen in unique spatiotemporal contexts. Interestingly, before 2 years of age, children are unable to form or store episodic memories for recall later in life, a phenomenon known as infantile amnesia. From 2 to 7 years of age, there are fewer memories than predicted based on a forgetting function alone, a phenomenon known as childhood amnesia. Here, we discuss the postnatal maturation of the primate hippocampal formation with the goal of characterizing the development of the neurobiological substrates thought to subserve the emergence of episodic memory. Distinct regions, layers and cells of the hippocampal formation exhibit different profiles of structural and molecular development during early postnatal life. The protracted period of neuronal addition and maturation in the dentate gyrus is accompanied by the late maturation of specific layers in different hippocampal regions that are located downstream from the dentate gyrus, particularly CA3. In contrast, distinct layers in several hippocampal regions, particularly CA1, which receive direct projections from the entorhinal cortex, exhibit an early maturation. In addition, hippocampal regions that are more highly interconnected with subcortical structures, including the subiculum, presubiculum, parasubiculum and CA2, mature even earlier. These findings, together with our studies of the development of human spatial memory, support the hypothesis that the differential maturation of distinct hippocampal circuits might underlie the differential emergence of specific "hippocampus-dependent" memory processes, culminating in the emergence of episodic memory concomitant with the maturation of all hippocampal circuits. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Shared mushroom body circuits underlie visual and olfactory memories in Drosophila

    Science.gov (United States)

    Vogt, Katrin; Schnaitmann, Christopher; Dylla, Kristina V; Knapek, Stephan; Aso, Yoshinori; Rubin, Gerald M; Tanimoto, Hiromu

    2014-01-01

    In nature, animals form memories associating reward or punishment with stimuli from different sensory modalities, such as smells and colors. It is unclear, however, how distinct sensory memories are processed in the brain. We established appetitive and aversive visual learning assays for Drosophila that are comparable to the widely used olfactory learning assays. These assays share critical features, such as reinforcing stimuli (sugar reward and electric shock punishment), and allow direct comparison of the cellular requirements for visual and olfactory memories. We found that the same subsets of dopamine neurons drive formation of both sensory memories. Furthermore, distinct yet partially overlapping subsets of mushroom body intrinsic neurons are required for visual and olfactory memories. Thus, our results suggest that distinct sensory memories are processed in a common brain center. Such centralization of related brain functions is an economical design that avoids the repetition of similar circuit motifs. DOI: http://dx.doi.org/10.7554/eLife.02395.001 PMID:25139953

  1. High density data recording for SSCL linac

    International Nuclear Information System (INIS)

    VanDeusen, A.L.; Crist, C.

    1993-01-01

    The Superconducting Super Collider Laboratory and AlliedSignal Aerospace have collaboratively developed a high density data monitoring system for beam diagnostic activities. The 128 channel data system is based on a custom multi-channel high speed digitizer card for the VXI bus. The card is referred to as a Modular Input VXI (MIX) digitizer. Multiple MIX cards are used in the complete system to achieve the necessary high channel density requirements. Each MIX digitizer card also contains programmable signal conditioning, and enough local memory to complete an entire beam scan without assistance from the host processor

  2. Photoionization and High Density Gas

    Science.gov (United States)

    Kallman, T.; Bautista, M.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We present results of calculations using the XSTAR version 2 computer code. This code is loosely based on the XSTAR v.1 code which has been available for public use for some time. However it represents an improvement and update in several major respects, including atomic data, code structure, user interface, and improved physical description of ionization/excitation. In particular, it now is applicable to high density situations in which significant excited atomic level populations are likely to occur. We describe the computational techniques and assumptions, and present sample runs with particular emphasis on high density situations.

  3. High-density multicore fibers

    DEFF Research Database (Denmark)

    Takenaga, K.; Matsuo, S.; Saitoh, K.

    2016-01-01

    High-density single-mode multicore fibers were designed and fabricated. A heterogeneous 30-core fiber realized a low crosstalk of −55 dB. A quasi-single-mode homogeneous 31-core fiber attained the highest core count as a single-mode multicore fiber.......High-density single-mode multicore fibers were designed and fabricated. A heterogeneous 30-core fiber realized a low crosstalk of −55 dB. A quasi-single-mode homogeneous 31-core fiber attained the highest core count as a single-mode multicore fiber....

  4. Navigating Monogamy: Nonapeptide Sensitivity in a Memory Neural Circuit May Shape Social Behavior and Mating Decisions

    Directory of Open Access Journals (Sweden)

    Alexander G. Ophir

    2017-07-01

    Full Text Available The role of memory in mating systems is often neglected despite the fact that most mating systems are defined in part by how animals use space. Monogamy, for example, is usually characterized by affiliative (e.g., pairbonding and defensive (e.g., mate guarding behaviors, but a high degree of spatial overlap in home range use is the easiest defining feature of monogamous animals in the wild. The nonapeptides vasopressin and oxytocin have been the focus of much attention for their importance in modulating social behavior, however this work has largely overshadowed their roles in learning and memory. To date, the understanding of memory systems and mechanisms governing social behavior have progressed relatively independently. Bridging these two areas will provide a deeper appreciation for understanding behavior, and in particular the mechanisms that mediate reproductive decision-making. Here, I argue that the ability to mate effectively as monogamous individuals is linked to the ability to track conspecifics in space. I discuss the connectivity across some well-known social and spatial memory nuclei, and propose that the nonapeptide receptors within these structures form a putative “socio-spatial memory neural circuit.” This purported circuit may function to integrate social and spatial information to shape mating decisions in a context-dependent fashion. The lateral septum and/or the nucleus accumbens, and neuromodulation therein, may act as an intermediary to relate socio-spatial information with social behavior. Identifying mechanisms responsible for relating information about the social world with mechanisms mediating mating tactics is crucial to fully appreciate the suite of factors driving reproductive decisions and social decision-making.

  5. Navigating Monogamy: Nonapeptide Sensitivity in a Memory Neural Circuit May Shape Social Behavior and Mating Decisions

    Science.gov (United States)

    Ophir, Alexander G.

    2017-01-01

    The role of memory in mating systems is often neglected despite the fact that most mating systems are defined in part by how animals use space. Monogamy, for example, is usually characterized by affiliative (e.g., pairbonding) and defensive (e.g., mate guarding) behaviors, but a high degree of spatial overlap in home range use is the easiest defining feature of monogamous animals in the wild. The nonapeptides vasopressin and oxytocin have been the focus of much attention for their importance in modulating social behavior, however this work has largely overshadowed their roles in learning and memory. To date, the understanding of memory systems and mechanisms governing social behavior have progressed relatively independently. Bridging these two areas will provide a deeper appreciation for understanding behavior, and in particular the mechanisms that mediate reproductive decision-making. Here, I argue that the ability to mate effectively as monogamous individuals is linked to the ability to track conspecifics in space. I discuss the connectivity across some well-known social and spatial memory nuclei, and propose that the nonapeptide receptors within these structures form a putative “socio-spatial memory neural circuit.” This purported circuit may function to integrate social and spatial information to shape mating decisions in a context-dependent fashion. The lateral septum and/or the nucleus accumbens, and neuromodulation therein, may act as an intermediary to relate socio-spatial information with social behavior. Identifying mechanisms responsible for relating information about the social world with mechanisms mediating mating tactics is crucial to fully appreciate the suite of factors driving reproductive decisions and social decision-making. PMID:28744194

  6. Post-Training Reversible Disconnection of the Ventral Hippocampal-Basolateral Amygdaloid Circuits Impairs Consolidation of Inhibitory Avoidance Memory in Rats

    Science.gov (United States)

    Wang, Gong-Wu; Liu, Jian; Wang, Xiao-Qin

    2017-01-01

    The ventral hippocampus (VH) and the basolateral amygdala (BLA) are both crucial in inhibitory avoidance (IA) memory. However, the exact role of the VH-BLA circuit in IA memory consolidation is unclear. This study investigated the effect of post-training reversible disconnection of the VH-BLA circuit in IA memory consolidation. Male Wistar rats…

  7. Canonical Cortical Circuit Model Explains Rivalry, Intermittent Rivalry, and Rivalry Memory.

    Directory of Open Access Journals (Sweden)

    Shashaank Vattikuti

    2016-05-01

    Full Text Available It has been shown that the same canonical cortical circuit model with mutual inhibition and a fatigue process can explain perceptual rivalry and other neurophysiological responses to a range of static stimuli. However, it has been proposed that this model cannot explain responses to dynamic inputs such as found in intermittent rivalry and rivalry memory, where maintenance of a percept when the stimulus is absent is required. This challenges the universality of the basic canonical cortical circuit. Here, we show that by including an overlooked realistic small nonspecific background neural activity, the same basic model can reproduce intermittent rivalry and rivalry memory without compromising static rivalry and other cortical phenomena. The background activity induces a mutual-inhibition mechanism for short-term memory, which is robust to noise and where fine-tuning of recurrent excitation or inclusion of sub-threshold currents or synaptic facilitation is unnecessary. We prove existence conditions for the mechanism and show that it can explain experimental results from the quartet apparent motion illusion, which is a prototypical intermittent rivalry stimulus.

  8. Proposal for a fast, zero suppressing circuit for the digitization of analog pulses over long memory times

    International Nuclear Information System (INIS)

    Bourgeois, F.

    1984-01-01

    This report describes the design principles of a fast (100 MHz) time and pulse height digitizer that can record up to 15 analog pulses over 10-80 μs memory times. Unlike other triggered circuits prepulse samples are recorded without the help of an analog delay line. The low power requirements of the circuit as well as its fast read-out characteristics make it very attractive for detectors with many digitizing channels. Conventional circuits are described as a reference for the evaluation of this new design. An ECL 10 K implementation of the circuit is presented in the third section. (orig.)

  9. Beyond the temporal pole: limbic memory circuit in the semantic variant of primary progressive aphasia.

    Science.gov (United States)

    Tan, Rachel H; Wong, Stephanie; Kril, Jillian J; Piguet, Olivier; Hornberger, Michael; Hodges, John R; Halliday, Glenda M

    2014-07-01

    Despite accruing evidence for relative preservation of episodic memory in the semantic variant of primary progressive aphasia (previously semantic dementia), the neural basis for this remains unclear, particularly in light of their well-established hippocampal involvement. We recently investigated the Papez network of memory structures across pathological subtypes of behavioural variant frontotemporal dementia and demonstrated severe degeneration of all relay nodes, with the anterior thalamus in particular emerging as crucial for intact episodic memory. The present study investigated the status of key components of Papez circuit (hippocampus, mammillary bodies, anterior thalamus, cingulate cortex) and anterior temporal cortex using volumetric and quantitative cell counting methods in pathologically-confirmed cases with semantic variant of primary progressive aphasia (n = 8; 61-83 years; three males), behavioural variant frontotemporal dementia with TDP pathology (n = 9; 53-82 years; six males) and healthy controls (n = 8, 50-86 years; four males). Behavioural variant frontotemporal dementia cases with TDP pathology were selected because of the association between the semantic variant of primary progressive aphasia and TDP pathology. Our findings revealed that the semantic variant of primary progressive aphasia and behavioural variant frontotemporal dementia show similar degrees of anterior thalamic atrophy. The mammillary bodies and hippocampal body and tail were preserved in the semantic variant of primary progressive aphasia but were significantly atrophic in behavioural variant frontotemporal dementia. Importantly, atrophy in the anterior thalamus and mild progressive atrophy in the body of the hippocampus emerged as the main memory circuit regions correlated with increasing dementia severity in the semantic variant of primary progressive aphasia. Quantitation of neuronal populations in the cingulate cortices confirmed the selective loss of anterior cingulate

  10. Utilization of Euler-Lagrange Equations in Circuits with Memory Elements

    Directory of Open Access Journals (Sweden)

    Z. Biolek

    2016-12-01

    Full Text Available It is well known that the equation of motion of a system can be set up using the Lagrangian and the dissipation function, which describe the conservative and dissipative parts of the system. However, this procedure, consisting in a systematic differentiation of the above state functions, cannot be used for circuits containing simultaneously conventional nonlinear elements such as the resistor, capacitor, and inductor, and their nonlinear memory versions – the memristor, memcapacitor, and meminductor. The paper provides a general solution to this problem and demonstrates it on the example of modeling Josephson’s junction.

  11. An analog memory integrated circuit for waveform sampling up to 900 MHz

    International Nuclear Information System (INIS)

    Haller, G.M.; Wooley, B.A.

    1994-01-01

    The potential of switched-capacitor technology for acquiring analog signals in high-energy physics (HEP) applications has been demonstrated in a number of analog memory designs. The design and implementation of a switched-capacitor memory suitable for capturing high-speed analog waveforms is described. Highlights of the presented circuit are a 900 MHz sampling frequency (generated on chip), input signal independent cell pedestal and sampling instances, and cell gains that are insensitive to component sizes. A two-channel version of the memory with 32 cells for each channel has been integrate in a 2-μm complementary metal oxide semiconductor (CMOS) process with polysilicon-to-polysilicon capacitors. The measured rms cell response variation in a channel after cell pedestal subtraction is less than 0.3 mV across the full input signal range. The cell-to-cell gain matching is better than 0.01% rms, and the nonlinearity is less than 0.03% for a 2.5-V input range. The dynamic range of the memory exceeds 13 bits, and the peak signal-to-(noise + distortion) ratio for a 21.4 MHz sine wave sampled at 900 MHz is 59 dB

  12. The Anterior Thalamus Provides A Subcortical Circuit Supporting Memory And Spatial Navigation

    Directory of Open Access Journals (Sweden)

    Shane M O‘Mara

    2013-08-01

    Full Text Available The anterior thalamic nuclei, a central component of Papez’ circuit, are generally assumed to be key constituents of the neural circuits responsible for certain categories of learning and memory. Supporting evidence for this contention is that damage to either of two brain regions, the medial temporal lobe and the medial diencephalon, is most consistently associated with anterograde amnesia. Within these respective regions, the hippocampal formation and the anterior thalamic nuclei (anteromedial, anteroventral, anterodorsal are the particular structures of interest. The extensive direct and indirect hippocampal-anterior thalamic interconnections and the presence of theta-modulated cells in both sites further support the hypothesis that these structures constitute a neuronal network crucial for memory and cognition. The major tool in understanding how the brain processes information is the analysis of neuronal output at each hierarchical level along the pathway of signal propagation coupled with neuroanatomical studies. Here, we discuss the electrophysiological properties of cells in the anterior thalamic nuclei with an emphasis on their role in spatial navigation. In addition, we describe neuroanatomical and functional relationships between the anterior thalamic nuclei and hippocampal formation.

  13. Plasma Diagnostics in High Density Reactors

    International Nuclear Information System (INIS)

    Daltrini, A. M.; Moshkalyov, S.; Monteiro, M. J. R.; Machida, M.; Kostryukov, A.; Besseler, E.; Biasotto, C.; Diniz, J. A.

    2006-01-01

    Langmuir electric probes and optical emission spectroscopy diagnostics were developed for applications in high density plasmas. These diagnostics were employed in two plasma sources: an electron cyclotron resonance (ECR) plasma and an RF driven inductively coupled plasma (ICP) plasma. Langmuir probes were tested using a number of probing dimensions, probe tip materials, circuits for probe bias and filters. Then, the results were compared with the optical spectroscopy measurements. With these diagnostics, analyses of various plasma processes were performed in both reactors. For example, it has been shown that species like NH radicals generated in gas phase can have critical impact on films deposited by ECR plasmas. In the ICP source, plasmas in atomic and molecular gases were shown to have different spatial distributions, likely due to nonlocal electron heating. The low-to-high density transitions in the ICP plasma were also studied. The role of metastables is shown to be significant in Ar plasmas, in contrast to plasmas with additions of molecular gases

  14. Bilateral generic working memory circuit requires left-lateralized addition for verbal processing.

    Science.gov (United States)

    Ray, Manaan Kar; Mackay, Clare E; Harmer, Catherine J; Crow, Timothy J

    2008-06-01

    According to the Baddeley-Hitch model, phonological and visuospatial representations are separable components of working memory (WM) linked by a central executive. The traditional view that the separation reflects the relative contribution of the 2 hemispheres (verbal WM--left; spatial WM--right) has been challenged by the position that a common bilateral frontoparietal network subserves both domains. Here, we test the hypothesis that there is a generic WM circuit that recruits additional specialized regions for verbal and spatial processing. We designed a functional magnetic resonance imaging paradigm to elicit activation in the WM circuit for verbal and spatial information using identical stimuli and applied this in 33 healthy controls. We detected left-lateralized quantitative differences in the left frontal and temporal lobe for verbal > spatial WM but no areas of activation for spatial > verbal WM. We speculate that spatial WM is analogous to a "generic" bilateral frontoparietal WM circuit we inherited from our great ape ancestors that evolved, by recruitment of additional left-lateralized frontal and temporal regions, to accommodate language.

  15. Uncertainty-Dependent Extinction of Fear Memory in an Amygdala-mPFC Neural Circuit Model

    Science.gov (United States)

    Li, Yuzhe; Nakae, Ken; Ishii, Shin; Naoki, Honda

    2016-01-01

    Uncertainty of fear conditioning is crucial for the acquisition and extinction of fear memory. Fear memory acquired through partial pairings of a conditioned stimulus (CS) and an unconditioned stimulus (US) is more resistant to extinction than that acquired through full pairings; this effect is known as the partial reinforcement extinction effect (PREE). Although the PREE has been explained by psychological theories, the neural mechanisms underlying the PREE remain largely unclear. Here, we developed a neural circuit model based on three distinct types of neurons (fear, persistent and extinction neurons) in the amygdala and medial prefrontal cortex (mPFC). In the model, the fear, persistent and extinction neurons encode predictions of net severity, of unconditioned stimulus (US) intensity, and of net safety, respectively. Our simulation successfully reproduces the PREE. We revealed that unpredictability of the US during extinction was represented by the combined responses of the three types of neurons, which are critical for the PREE. In addition, we extended the model to include amygdala subregions and the mPFC to address a recent finding that the ventral mPFC (vmPFC) is required for consolidating extinction memory but not for memory retrieval. Furthermore, model simulations led us to propose a novel procedure to enhance extinction learning through re-conditioning with a stronger US; strengthened fear memory up-regulates the extinction neuron, which, in turn, further inhibits the fear neuron during re-extinction. Thus, our models increased the understanding of the functional roles of the amygdala and vmPFC in the processing of uncertainty in fear conditioning and extinction. PMID:27617747

  16. Uncertainty-Dependent Extinction of Fear Memory in an Amygdala-mPFC Neural Circuit Model.

    Science.gov (United States)

    Li, Yuzhe; Nakae, Ken; Ishii, Shin; Naoki, Honda

    2016-09-01

    Uncertainty of fear conditioning is crucial for the acquisition and extinction of fear memory. Fear memory acquired through partial pairings of a conditioned stimulus (CS) and an unconditioned stimulus (US) is more resistant to extinction than that acquired through full pairings; this effect is known as the partial reinforcement extinction effect (PREE). Although the PREE has been explained by psychological theories, the neural mechanisms underlying the PREE remain largely unclear. Here, we developed a neural circuit model based on three distinct types of neurons (fear, persistent and extinction neurons) in the amygdala and medial prefrontal cortex (mPFC). In the model, the fear, persistent and extinction neurons encode predictions of net severity, of unconditioned stimulus (US) intensity, and of net safety, respectively. Our simulation successfully reproduces the PREE. We revealed that unpredictability of the US during extinction was represented by the combined responses of the three types of neurons, which are critical for the PREE. In addition, we extended the model to include amygdala subregions and the mPFC to address a recent finding that the ventral mPFC (vmPFC) is required for consolidating extinction memory but not for memory retrieval. Furthermore, model simulations led us to propose a novel procedure to enhance extinction learning through re-conditioning with a stronger US; strengthened fear memory up-regulates the extinction neuron, which, in turn, further inhibits the fear neuron during re-extinction. Thus, our models increased the understanding of the functional roles of the amygdala and vmPFC in the processing of uncertainty in fear conditioning and extinction.

  17. The interhemispheric CA1 circuit governs rapid generalisation but not fear memory.

    Science.gov (United States)

    Zhou, Heng; Xiong, Gui-Jing; Jing, Liang; Song, Ning-Ning; Pu, De-Lin; Tang, Xun; He, Xiao-Bing; Xu, Fu-Qiang; Huang, Jing-Fei; Li, Ling-Jiang; Richter-Levin, Gal; Mao, Rong-Rong; Zhou, Qi-Xin; Ding, Yu-Qiang; Xu, Lin

    2017-12-19

    Encoding specificity theory predicts most effective recall by the original conditions at encoding, while generalization endows recall flexibly under circumstances which deviate from the originals. The CA1 regions have been implicated in memory and generalization but whether and which locally separated mechanisms are involved is not clear. We report here that fear memory is quickly formed, but generalization develops gradually over 24 h. Generalization but not fear memory is impaired by inhibiting ipsilateral (ips) or contralateral (con) CA1, and by optogenetic silencing of the ipsCA1 projections onto conCA1. By contrast, in vivo fEPSP recordings reveal that ipsCA1-conCA1 synaptic efficacy is increased with delay over 24 h when generalization is formed but it is unchanged if generalization is disrupted. Direct excitation of ipsCA1-conCA1 synapses using chemogenetic hM3Dq facilitates generalization formation. Thus, rapid generalization is an active process dependent on bilateral CA1 regions, and encoded by gradual synaptic learning in ipsCA1-conCA1 circuit.

  18. Pathological changes in hippocampal neuronal circuits underlie age-associated neurodegeneration and memory loss: positive clue toward SAD.

    Science.gov (United States)

    Moorthi, P; Premkumar, P; Priyanka, R; Jayachandran, K S; Anusuyadevi, M

    2015-08-20

    Among vertebrates hippocampus forms the major component of the brain in consolidating information from short-term memory to long-term memory. Aging is considered as the major risk factor for memory impairment in sporadic Alzheimer's disease (SAD) like pathology. Present study thus aims at investigating whether age-specific degeneration of neuronal-circuits in hippocampal formation (neural-layout of Subiculum-hippocampus proper-dentate gyrus (DG)-entorhinal cortex (EC)) results in cognitive impairment. Furthermore, the neuroprotective effect of Resveratrol (RSV) was attempted to study in the formation of hippocampal neuronal-circuits. Radial-Arm-Maze was conducted to evaluate hippocampal-dependent spatial and learning memory in control and experimental rats. Nissl staining of frontal cortex (FC), subiculum, hippocampal-proper (CA1→CA2→CA3→CA4), DG, amygdala, cerebellum, thalamus, hypothalamus, layers of temporal and parietal lobe of the neocortex were examined for pathological changes in young and aged wistar rats, with and without RSV. Hippocampal trisynaptic circuit (EC layerII→DG→CA3→CA1) forming new memory and monosynaptic circuit (EC→CA1) that strengthen old memories were found disturbed in aged rats. Loss of Granular neuron observed in DG and polymorphic cells of CA4 can lead to decreased mossy fibers disturbing neural-transmission (CA4→CA3) in perforant pathway. Further, intensity of nissl granules (stratum lacunosum moleculare (SLM)-SR-SO) of CA3 pyramidal neurons was decreased, disturbing the communication in schaffer collaterals (CA3-CA1) during aging. We also noticed disarranged neuronal cell layer in Subiculum (presubiculum (PrS)-parasubiculum (PaS)), interfering output from hippocampus to prefrontal cortex (PFC), EC, hypothalamus, and amygdala that may result in interruption of thought processes. We conclude from our observations that poor memory performance of aged rats as evidenced through radial arm maze (RAM) analysis was due to the

  19. Disinhibition in learning and memory circuits: New vistas for somatostatin interneurons and long-term synaptic plasticity.

    Science.gov (United States)

    Artinian, Julien; Lacaille, Jean-Claude

    2017-11-23

    Neural circuit functions involve finely controlled excitation/inhibition interactions that allow complex neuronal computations and support high order brain functions such as learning and memory. Disinhibition, defined as a transient brake on inhibition that favors excitation, recently appeared to be a conserved circuit mechanism implicated in various functions such as sensory processing, learning and memory. Although vasoactive intestinal polypeptide (VIP) interneurons are considered to be the main disinhibitory cells, recent studies highlighted a pivotal role of somatostatin (SOM) interneurons in inhibiting GABAergic interneurons and promoting principal cell activation. Interestingly, long-term potentiation of excitatory input synapses onto hippocampal SOM interneurons is proposed as a lasting mechanism for regulation of disinhibition of principal neurons. Such regulation of network metaplasticity may be important for hippocampal-dependent learning and memory. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Grand Research Plan for Neural Circuits of Emotion and Memory — Current status of neural circuit studies in China

    OpenAIRE

    Zhu, Yuan-Gui; Cao, He-Qi; Dong, Er-Dan

    2013-01-01

    During recent years, major advances have been made in neuroscience, i.e., asynchronous release, three-dimensional structural data sets, saliency maps, magnesium in brain research, and new functional roles of long non-coding RNAs. Especially, the development of optogenetic technology provides access to important information about relevant neural circuits by allowing the activation of specific neurons in awake mammals and directly observing the resulting behavior. The Grand Research Plan for Ne...

  1. Listening to polyphonic music recruits domain-general attention and working memory circuits.

    Science.gov (United States)

    Janata, Petr; Tillmann, Barbara; Bharucha, Jamshed J

    2002-06-01

    Polyphonic music combines multiple auditory streams to create complex auditory scenes, thus providing a tool for investigating the neural mechanisms that orient attention in natural auditory contexts. Across two fMRI experiments, we varied stimuli and task demands in order to identify the cortical areas that are activated during attentive listening to real music. In individual experiments and in a conjunction analysis of the two experiments, we found bilateral blood oxygen level dependent (BOLD) signal increases in temporal (the superior temporal gyrus), parietal (the intraparietal sulcus), and frontal (the precentral sulcus, the inferior frontal sulcus and gyrus, and the frontal operculum) areas during selective and global listening, as compared with passive rest without musical stimulation. Direct comparisons of the listening conditions showed significant differences between attending to single timbres (instruments) and attending across multiple instruments, although the patterns that were observed depended on the relative demands of the tasks being compared. The overall pattern of BOLD signal increases indicated that attentive listening to music recruits neural circuits underlying multiple forms of working memory, attention, semantic processing, target detection, and motor imagery. Thus, attentive listening to music appears to be enabled by areas that serve general functions, rather than by music-specific cortical modules.

  2. Individual language experience modulates rapid formation of cortical memory circuits for novel words

    Science.gov (United States)

    Kimppa, Lilli; Kujala, Teija; Shtyrov, Yury

    2016-01-01

    Mastering multiple languages is an increasingly important ability in the modern world; furthermore, multilingualism may affect human learning abilities. Here, we test how the brain’s capacity to rapidly form new representations for spoken words is affected by prior individual experience in non-native language acquisition. Formation of new word memory traces is reflected in a neurophysiological response increase during a short exposure to novel lexicon. Therefore, we recorded changes in electrophysiological responses to phonologically native and non-native novel word-forms during a perceptual learning session, in which novel stimuli were repetitively presented to healthy adults in either ignore or attend conditions. We found that larger number of previously acquired languages and earlier average age of acquisition (AoA) predicted greater response increase to novel non-native word-forms. This suggests that early and extensive language experience is associated with greater neural flexibility for acquiring novel words with unfamiliar phonology. Conversely, later AoA was associated with a stronger response increase for phonologically native novel word-forms, indicating better tuning of neural linguistic circuits to native phonology. The results suggest that individual language experience has a strong effect on the neural mechanisms of word learning, and that it interacts with the phonological familiarity of the novel lexicon. PMID:27444206

  3. Transitions between Multiband Oscillatory Patterns Characterize Memory-Guided Perceptual Decisions in Prefrontal Circuits.

    Science.gov (United States)

    Wimmer, Klaus; Ramon, Marc; Pasternak, Tatiana; Compte, Albert

    2016-01-13

    between sensory and cognitive processing. Here, we studied rhythmic electrical activity in the monkey prefrontal cortex, an area implicated in working memory, decision making, and executive control. Monkeys had to identify and remember a visual motion pattern and compare it to a second pattern. We found orderly transitions between rhythmic activity where the same frequency channels were active in all ongoing prefrontal computations. This supports prefrontal circuit dynamics that transitions rapidly between complex rhythmic patterns during structured cognitive tasks. Copyright © 2016 the authors 0270-6474/16/360489-17$15.00/0.

  4. Compensated readout for high-density MOS-gated memristor crossbar array

    KAUST Repository

    Zidan, Mohammed A.

    2015-01-01

    Leakage current is one of the main challenges facing high-density MOS-gated memristor arrays. In this study, we show that leakage current ruins the memory readout process for high-density arrays, and analyze the tradeoff between the array density and its power consumption. We propose a novel readout technique and its underlying circuitry, which is able to compensate for the transistor leakage-current effect in the high-density gated memristor array.

  5. Memristor-based nanoelectronic computing circuits and architectures

    CERN Document Server

    Vourkas, Ioannis

    2016-01-01

    This book considers the design and development of nanoelectronic computing circuits, systems and architectures focusing particularly on memristors, which represent one of today’s latest technology breakthroughs in nanoelectronics. The book studies, explores, and addresses the related challenges and proposes solutions for the smooth transition from conventional circuit technologies to emerging computing memristive nanotechnologies. Its content spans from fundamental device modeling to emerging storage system architectures and novel circuit design methodologies, targeting advanced non-conventional analog/digital massively parallel computational structures. Several new results on memristor modeling, memristive interconnections, logic circuit design, memory circuit architectures, computer arithmetic systems, simulation software tools, and applications of memristors in computing are presented. High-density memristive data storage combined with memristive circuit-design paradigms and computational tools applied t...

  6. Memristor Circuits and Systems

    KAUST Repository

    Zidan, Mohammed A.

    2015-05-01

    Current CMOS-based technologies are facing design challenges related to the continuous scaling down of the minimum feature size, according to Moore’s law. Moreover, conventional computing architecture is no longer an effective way of fulfilling modern applications demands, such as big data analysis, pattern recognition, and vector processing. Therefore, there is an exigent need to shift to new technologies, at both the architecture and the device levels. Recently, memristor devices and structures attracted attention for being promising candidates for this job. Memristor device adds a new dimension for designing novel circuits and systems. In addition, high-density memristor-based crossbar is widely considered to be the essential element for future memory and bio-inspired computing systems. However, numerous challenges need to be addressed before the memristor genuinely replaces current memory and computing technologies, which is the motivation behind this research effort. In order to address the technology challenges, we begin by fabricating and modeling the memristor device. The devices fabricated at our local clean room enriched our understanding of the memristive phenomenon and enabled the experimental testing for our memristor-based circuits. Moreover, our proposed mathematical modeling for memristor behavior is an essential element for the theoretical circuit design stage. Designing and addressing the challenges of memristor systems with practical complexity, however, requires an extra step, which takes the form of a reliable and modular simulation platform. We, therefore, built a new simulation platform for the resistive crossbar, which can simulate realistic size arrays filled with real memory data. In addition, this simulation platform includes various crossbar nonidealities in order to obtain accurate simulation results. Consequently, we were able to address the significant challenges facing the high density memristor crossbar, as the building block for

  7. High density data storage principle, technology, and materials

    CERN Document Server

    Zhu, Daoben

    2009-01-01

    The explosive increase in information and the miniaturization of electronic devices demand new recording technologies and materials that combine high density, fast response, long retention time and rewriting capability. As predicted, the current silicon-based computer circuits are reaching their physical limits. Further miniaturization of the electronic components and increase in data storage density are vital for the next generation of IT equipment such as ultra high-speed mobile computing, communication devices and sophisticated sensors. This original book presents a comprehensive introduction to the significant research achievements on high-density data storage from the aspects of recording mechanisms, materials and fabrication technologies, which are promising for overcoming the physical limits of current data storage systems. The book serves as an useful guide for the development of optimized materials, technologies and device structures for future information storage, and will lead readers to the fascin...

  8. Floating-Gate Manipulated Graphene-Black Phosphorus Heterojunction for Nonvolatile Ambipolar Schottky Junction Memories, Memory Inverter Circuits, and Logic Rectifiers.

    Science.gov (United States)

    Li, Dong; Chen, Mingyuan; Zong, Qijun; Zhang, Zengxing

    2017-10-11

    The Schottky junction is an important unit in electronics and optoelectronics. However, its properties greatly degrade with device miniaturization. The fast development of circuits has fueled a rapid growth in the study of two-dimensional (2D) crystals, which may lead to breakthroughs in the semiconductor industry. Here we report a floating-gate manipulated nonvolatile ambipolar Schottky junction memory from stacked all-2D layers of graphene-BP/h-BN/graphene (BP, black phosphorus; h-BN, hexagonal boron nitride) in a designed floating-gate field-effect Schottky barrier transistor configuration. By manipulating the voltage pulse applied to the control gate, the device exhibits ambipolar characteristics and can be tuned to act as graphene-p-BP or graphene-n-BP junctions with reverse rectification behavior. Moreover, the junction exhibits good storability properties of more than 10 years and is also programmable. On the basis of these characteristics, we further demonstrate the application of the device to dual-mode nonvolatile Schottky junction memories, memory inverter circuits, and logic rectifiers.

  9. Measuring RF circuits exhibiting nonlinear responses combined with short and long term memory effects

    NARCIS (Netherlands)

    Janssen, E.J.G.; Milosevic, D.; Baltus, P.G.M.

    2010-01-01

    All RF circuits that incorporate active devices exhibit nonlinear behavior. Nonlinearities result in signal distortion, and therefore state the upper limit of the dynamic range of the circuits. A measure for linearity used quite commonly in RF is the P1dB and/or IP3 point. These quantities are

  10. Detection of central circuits implicated in the formation of novel pain memories

    Directory of Open Access Journals (Sweden)

    Upadhyay J

    2016-09-01

    Full Text Available Jaymin Upadhyay,1 Julia Granitzka,1 Thomas Bauermann,2 Ulf Baumgärtner,3 Markus Breimhorst,1 Rolf-Detlef Treede,3 Frank Birklein1 1Department of Neurology, 2Department of Neuroradiology, University Medical Centre, Johannes Gutenberg University Mainz, Mainz, 3Department of Neurophysiology, Center for Biomedicine and Medical Technology Mannheim (CBTM, Heidelberg University, Mannheim, Germany Abstract: Being able to remember physically and emotionally painful events in one’s own past may shape behavior, and can create an aversion to a variety of situations. Pain imagination is a related process that may include recall of past experiences, in addition to production of sensory and emotional percepts without external stimuli. This study aimed to understand 1 the central nervous system processes that underlie pain imagination, 2 the retrieval of pain memories, and 3 to compare the latter with visual object memory. These goals were achieved by longitudinally investigating brain function with functional magnetic resonance imaging in a unique group of healthy volunteers who had never experienced tooth pain. In these subjects, we compared brain responses elicited during three experimental conditions in the following order: imagination of tooth pain (pain imagination, remembering one’s own house (object memory, and remembrance of tooth pain following an episode of induced acute tooth pain (pain memory. Key observations stemming from group-level conjunction analyses revealed common activation in the posterior parietal cortex for both pain imagination and pain memory, while object and pain memory each had strong activation predominantly within the middle frontal gyrus. When contrasting pain imagination and memory, significant activation differences were observed in subcortical structures (ie, parahippocampus – pain imagination > pain memory; midbrain – pain memory > pain imagination. Importantly, these findings were observed in the presence of

  11. High Density Digital Data Storage System

    Science.gov (United States)

    Wright, Kenneth D., II; Gray, David L.; Rowland, Wayne D.

    1991-01-01

    The High Density Digital Data Storage System was designed to provide a cost effective means for storing real-time data from the field-deployable digital acoustic measurement system. However, the high density data storage system is a standalone system that could provide a storage solution for many other real time data acquisition applications. The storage system has inputs for up to 20 channels of 16-bit digital data. The high density tape recorders presently being used in the storage system are capable of storing over 5 gigabytes of data at overall transfer rates of 500 kilobytes per second. However, through the use of data compression techniques the system storage capacity and transfer rate can be doubled. Two tape recorders have been incorporated into the storage system to produce a backup tape of data in real-time. An analog output is provided for each data channel as a means of monitoring the data as it is being recorded.

  12. Interaction between basal ganglia and limbic circuits in learning and memory processes.

    Science.gov (United States)

    Calabresi, Paolo; Picconi, Barbara; Tozzi, Alessandro; Ghiglieri, Veronica

    2016-01-01

    Hippocampus and striatum play distinctive roles in memory processes since declarative and non-declarative memory systems may act independently. However, hippocampus and striatum can also be engaged to function in parallel as part of a dynamic system to integrate previous experience and adjust behavioral responses. In these structures the formation, storage, and retrieval of memory require a synaptic mechanism that is able to integrate multiple signals and to translate them into persistent molecular traces at both the corticostriatal and hippocampal/limbic synapses. The best cellular candidate for this complex synthesis is represented by long-term potentiation (LTP). A common feature of LTP expressed in these two memory systems is the critical requirement of convergence and coincidence of glutamatergic and dopaminergic inputs to the dendritic spines of the neurons expressing this form of synaptic plasticity. In experimental models of Parkinson's disease abnormal accumulation of α-synuclein affects these two memory systems by altering two major synaptic mechanisms underlying cognitive functions in cholinergic striatal neurons, likely implicated in basal ganglia dependent operative memory, and in the CA1 hippocampal region, playing a central function in episodic/declarative memory processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Magnetization of High Density Hadronic Fluid

    DEFF Research Database (Denmark)

    Bohr, Henrik; Providencia, Constanca; da Providencia, João

    2012-01-01

    In the present paper the magnetization of a high density relativistic fluid of elementary particles is studied. At very high densities, such as may be found in the interior of a neutron star, when the external magnetic field is gradually increased, the energy of the normal phase of the fluid...... in the particle fluid. For nuclear densities above 2 to 3 rho(0), where rho(0) is the equilibrium nuclear density, the resulting magnetic field turns out to be rather huge, of the order of 10(17) Gauss....

  14. Ultra-High Density Spectral Storage Materials

    National Research Council Canada - National Science Library

    Hasan, Zameer U

    2002-01-01

    .... Being atomic scale storage, spectral storage has the potential of providing orders of magnitude denser memories than present day memories that depend on the hulk properties of the storage medium...

  15. Single-Cell Memory Regulates a Neural Circuit for Sensory Behavior.

    Science.gov (United States)

    Kobayashi, Kyogo; Nakano, Shunji; Amano, Mutsuki; Tsuboi, Daisuke; Nishioka, Tomoki; Ikeda, Shingo; Yokoyama, Genta; Kaibuchi, Kozo; Mori, Ikue

    2016-01-05

    Unveiling the molecular and cellular mechanisms underlying memory has been a challenge for the past few decades. Although synaptic plasticity is proven to be essential for memory formation, the significance of "single-cell memory" still remains elusive. Here, we exploited a primary culture system for the analysis of C. elegans neurons and show that a single thermosensory neuron has an ability to form, retain, and reset a temperature memory. Genetic and proteomic analyses found that the expression of the single-cell memory exhibits inter-individual variability, which is controlled by the evolutionarily conserved CaMKI/IV and Raf pathway. The variable responses of a sensory neuron influenced the neural activity of downstream interneurons, suggesting that modulation of the sensory neurons ultimately determines the behavioral output in C. elegans. Our results provide proof of single-cell memory and suggest that the individual differences in neural responses at the single-cell level can confer individuality. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Supernovae and high density nuclear matter

    International Nuclear Information System (INIS)

    Kahana, S.

    1986-01-01

    The role of the nuclear equation of state (EOS) in producing prompt supernova explosions is examined. Results of calculations of Baron, Cooperstein, and Kahana incorporating general relativity and a new high density EOS are presented, and the relevance of these calculations to laboratory experiments with heavy ions considered. 31 refs., 6 figs., 2 tabs

  17. Supernovae and high density nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Kahana, S.

    1986-01-01

    The role of the nuclear equation of state (EOS) in producing prompt supernova explosions is examined. Results of calculations of Baron, Cooperstein, and Kahana incorporating general relativity and a new high density EOS are presented, and the relevance of these calculations to laboratory experiments with heavy ions considered. 31 refs., 6 figs., 2 tabs.

  18. High Density GEOSAT/GM Altimeter Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The high density Geosat/GM altimeter data south of 30 S have finally arrived. In addition, ERS-1 has completed more than 6 cycles of its 35-day repeat track. These...

  19. High density aseismic spent fuel storage racks

    International Nuclear Information System (INIS)

    Louvat, J.P.

    1985-05-01

    After the reasons of the development of high density aseismic spent fuel racks by FRAMATOME and LEMER, a description is presented, as also the codes, standards and regulations used to design this FRAMATOME storage rack. Tests have been carried out concerning criticality, irradiation of Cadminox, corrosion of the cell, and the seismic behaviour

  20. Single-Readout High-Density Memristor Crossbar

    KAUST Repository

    Zidan, M. A.

    2016-01-07

    High-density memristor-crossbar architecture is a very promising technology for future computing systems. The simplicity of the gateless-crossbar structure is both its principal advantage and the source of undesired sneak-paths of current. This parasitic current could consume an enormous amount of energy and ruin the readout process. We introduce new adaptive-threshold readout techniques that utilize the locality and hierarchy properties of the computer-memory system to address the sneak-paths problem. The proposed methods require a single memory access per pixel for an array readout. Besides, the memristive crossbar consumes an order of magnitude less power than state-of-the-art readout techniques.

  1. Single-Readout High-Density Memristor Crossbar

    KAUST Repository

    Zidan, M. A.; Omran, Hesham; Naous, Rawan; Salem, Ahmed Sultan; Fahmy, H. A. H.; Lu, W. D.; Salama, Khaled N.

    2016-01-01

    High-density memristor-crossbar architecture is a very promising technology for future computing systems. The simplicity of the gateless-crossbar structure is both its principal advantage and the source of undesired sneak-paths of current. This parasitic current could consume an enormous amount of energy and ruin the readout process. We introduce new adaptive-threshold readout techniques that utilize the locality and hierarchy properties of the computer-memory system to address the sneak-paths problem. The proposed methods require a single memory access per pixel for an array readout. Besides, the memristive crossbar consumes an order of magnitude less power than state-of-the-art readout techniques.

  2. Distinct Circuits for the Formation and Retrieval of an Imprinted Olfactory Memory.

    Science.gov (United States)

    Jin, Xin; Pokala, Navin; Bargmann, Cornelia I

    2016-02-11

    Memories formed early in life are particularly stable and influential, representing privileged experiences that shape enduring behaviors. We show that exposing newly hatched C. elegans to pathogenic bacteria results in persistent aversion to those bacterial odors, whereas adult exposure generates only transient aversive memory. Long-lasting imprinted aversion has a critical period in the first larval stage and is specific to the experienced pathogen. Distinct groups of neurons are required during formation (AIB, RIM) and retrieval (AIY, RIA) of the imprinted memory. RIM synthesizes the neuromodulator tyramine, which is required in the L1 stage for learning. AIY memory retrieval neurons sense tyramine via the SER-2 receptor, which is essential for imprinted, but not for adult-learned, aversion. Odor responses in several neurons, most notably RIA, are altered in imprinted animals. These findings provide insight into neuronal substrates of different forms of memory, and lay a foundation for further understanding of early learning. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Modulation of learning and memory by the targeted deletion of the circadian clock gene Bmal1 in forebrain circuits.

    Science.gov (United States)

    Snider, Kaitlin H; Dziema, Heather; Aten, Sydney; Loeser, Jacob; Norona, Frances E; Hoyt, Kari; Obrietan, Karl

    2016-07-15

    A large body of literature has shown that the disruption of circadian clock timing has profound effects on mood, memory and complex thinking. Central to this time keeping process is the master circadian pacemaker located within the suprachiasmatic nucleus (SCN). Of note, within the central nervous system, clock timing is not exclusive to the SCN, but rather, ancillary oscillatory capacity has been detected in a wide range of cell types and brain regions, including forebrain circuits that underlie complex cognitive processes. These observations raise questions about the hierarchical and functional relationship between the SCN and forebrain oscillators, and, relatedly, about the underlying clock-gated synaptic circuitry that modulates cognition. Here, we utilized a clock knockout strategy in which the essential circadian timing gene Bmal1 was selectively deleted from excitatory forebrain neurons, whilst the SCN clock remained intact, to test the role of forebrain clock timing in learning, memory, anxiety, and behavioral despair. With this model system, we observed numerous effects on hippocampus-dependent measures of cognition. Mice lacking forebrain Bmal1 exhibited deficits in both acquisition and recall on the Barnes maze. Notably, loss of forebrain Bmal1 abrogated time-of-day dependent novel object location memory. However, the loss of Bmal1 did not alter performance on the elevated plus maze, open field assay, and tail suspension test, indicating that this phenotype specifically impairs cognition but not affect. Together, these data suggest that forebrain clock timing plays a critical role in shaping the efficiency of learning and memory retrieval over the circadian day. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. The GLUEchip: A custom VLSI chip for detectors readout and associative memories circuits

    International Nuclear Information System (INIS)

    Amendolia, S.R.; Galeotti, S.; Morsani, F.; Passuello, D.; Ristori, L.; Turini, N.

    1993-01-01

    An associative memory full-custom VLSI chip for pattern recognition has been designed and tested in the past years. It's the AMchip, that contains 128 patterns of 60 bits each. To expand the pattern capacity of an Associative Memory bank, the custom VLSI GLUEchip has been developed. The GLUEchip allows the interconnection of up to 16 AMchips or up to 16 GLUEchips: the resulting tree-like structure works like a single AMchip with an output pipelined structure and a pattern capacity increased by a factor 16 for each GLUEchip used

  5. Some recent efforts toward high density implosions

    International Nuclear Information System (INIS)

    McClellan, G.E.

    1980-01-01

    Some recent Livermore efforts towards achieving high-density implosions are presented. The implosion dynamics necessary to compress DT fuel to 10 to 100 times liquid density are discussed. Methods of diagnosing the maximum DT density for a specific design are presented along with results to date. The dynamics of the double-shelled target with an exploding outer shell are described, and some preliminary experimental results are presented

  6. Framatome offers new high density Cadminox racks

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    Framatome have developed a new material called Cadminox for use in high density spent fuel storage racks. It is claimed that Cadminox will remain stable stable in pond storage when racks submerged in boronated water are irradiated by the spent fuel they contain. A brief description of the storage module is given, including the aseismic bearing device which minimises loads on pond walls, racks and fuel assemblies. (UK)

  7. Spin polarization in high density quark matter

    DEFF Research Database (Denmark)

    Bohr, Henrik; Panda, Prafulla K.; Providênci, Constanca

    2013-01-01

    We investigate the occurrence of a ferromagnetic phase transition in high density hadronic matter (e.g., in the interior of a neutron star). This could be induced by a four-fermion interaction analogous to the one which is responsible for chiral symmetry breaking in the Nambu-Jona-Lasinio model, ...... the so-called 2 flavor super-conducting phase to the ferromagnetic phase arises. The color-flavor-locked phase may be completely hidden by the FP....

  8. The car parking problem at high densities

    Science.gov (United States)

    Burgos, E.; Bonadeo, H.

    1989-04-01

    The radial distribution functions of random 1-D systems of sequential hard rods have been studied in the range of very high densities. It is found that as the number of samples rejected before completion increases, anomalies in the pairwise distribution functions arise. These are discussed using analytical solutions for systems of three rods and numerical simulations with twelve rods. The probabilities of different spatial orderings with respect to the sequential order are examined.

  9. Engineering non-linear resonator mode interactions in circuit QED by continuous driving: Manipulation of a photonic quantum memory

    Science.gov (United States)

    Reagor, Matthew; Pfaff, Wolfgang; Heeres, Reinier; Ofek, Nissim; Chou, Kevin; Blumoff, Jacob; Leghtas, Zaki; Touzard, Steven; Sliwa, Katrina; Holland, Eric; Albert, Victor V.; Frunzio, Luigi; Devoret, Michel H.; Jiang, Liang; Schoelkopf, Robert J.

    2015-03-01

    Recent advances in circuit QED have shown great potential for using microwave resonators as quantum memories. In particular, it is possible to encode the state of a quantum bit in non-classical photonic states inside a high-Q linear resonator. An outstanding challenge is to perform controlled operations on such a photonic state. We demonstrate experimentally how a continuous drive on a transmon qubit coupled to a high-Q storage resonator can be used to induce non-linear dynamics of the resonator. Tailoring the drive properties allows us to cancel or enhance non-linearities in the system such that we can manipulate the state stored in the cavity. This approach can be used to either counteract undesirable evolution due to the bare Hamiltonian of the system or, ultimately, to perform logical operations on the state encoded in the cavity field. Our method provides a promising pathway towards performing universal control for quantum states stored in high-coherence resonators in the circuit QED platform.

  10. Evidence for a Specific Integrative Mechanism for Episodic Memory Mediated by AMPA/kainate Receptors in a Circuit Involving Medial Prefrontal Cortex and Hippocampal CA3 Region.

    Science.gov (United States)

    de Souza Silva, Maria A; Huston, Joseph P; Wang, An-Li; Petri, David; Chao, Owen Yuan-Hsin

    2016-07-01

    We asked whether episodic-like memory requires neural mechanisms independent of those that mediate its component memories for "what," "when," and "where," and if neuronal connectivity between the medial prefrontal cortex (mPFC) and the hippocampus (HPC) CA3 subregion is essential for episodic-like memory. Unilateral lesion of the mPFC was combined with unilateral lesion of the CA3 in the ipsi- or contralateral hemispheres in rats. Episodic-like memory was tested using a task, which assesses the integration of memories for "what, where, and when" concomitantly. Tests for novel object recognition (what), object place (where), and temporal order memory (when) were also applied. Bilateral disconnection of the mPFC-CA3 circuit by N-methyl-d-aspartate (NMDA) lesions disrupted episodic-like memory, but left the component memories for object, place, and temporal order, per se, intact. Furthermore, unilateral NMDA lesion of the CA3 plus injection of (6-cyano-7-nitroquinoxaline-2,3-dione) (CNQX) (AMPA/kainate receptor antagonist), but not AP-5 (NMDA receptor antagonist), into the contralateral mPFC also disrupted episodic-like memory, indicating the mPFC AMPA/kainate receptors as critical for this circuit. These results argue for a selective neural system that specifically subserves episodic memory, as it is not critically involved in the control of its component memories for object, place, and time. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. Multiplexed, high density electrophysiology with nanofabricated neural probes.

    Directory of Open Access Journals (Sweden)

    Jiangang Du

    Full Text Available Extracellular electrode arrays can reveal the neuronal network correlates of behavior with single-cell, single-spike, and sub-millisecond resolution. However, implantable electrodes are inherently invasive, and efforts to scale up the number and density of recording sites must compromise on device size in order to connect the electrodes. Here, we report on silicon-based neural probes employing nanofabricated, high-density electrical leads. Furthermore, we address the challenge of reading out multichannel data with an application-specific integrated circuit (ASIC performing signal amplification, band-pass filtering, and multiplexing functions. We demonstrate high spatial resolution extracellular measurements with a fully integrated, low noise 64-channel system weighing just 330 mg. The on-chip multiplexers make possible recordings with substantially fewer external wires than the number of input channels. By combining nanofabricated probes with ASICs we have implemented a system for performing large-scale, high-density electrophysiology in small, freely behaving animals that is both minimally invasive and highly scalable.

  12. Ultra-Stretchable Interconnects for High-Density Stretchable Electronics

    Directory of Open Access Journals (Sweden)

    Salman Shafqat

    2017-09-01

    Full Text Available The exciting field of stretchable electronics (SE promises numerous novel applications, particularly in-body and medical diagnostics devices. However, future advanced SE miniature devices will require high-density, extremely stretchable interconnects with micron-scale footprints, which calls for proven standardized (complementary metal-oxide semiconductor (CMOS-type process recipes using bulk integrated circuit (IC microfabrication tools and fine-pitch photolithography patterning. Here, we address this combined challenge of microfabrication with extreme stretchability for high-density SE devices by introducing CMOS-enabled, free-standing, miniaturized interconnect structures that fully exploit their 3D kinematic freedom through an interplay of buckling, torsion, and bending to maximize stretchability. Integration with standard CMOS-type batch processing is assured by utilizing the Flex-to-Rigid (F2R post-processing technology to make the back-end-of-line interconnect structures free-standing, thus enabling the routine microfabrication of highly-stretchable interconnects. The performance and reproducibility of these free-standing structures is promising: an elastic stretch beyond 2000% and ultimate (plastic stretch beyond 3000%, with <0.3% resistance change, and >10 million cycles at 1000% stretch with <1% resistance change. This generic technology provides a new route to exciting highly-stretchable miniature devices.

  13. Investigation of 6T SRAM memory circuit using high-k dielectrics based nano scale junctionless transistor

    Science.gov (United States)

    Charles Pravin, J.; Nirmal, D.; Prajoon, P.; Mohan Kumar, N.; Ajayan, J.

    2017-04-01

    In this paper the Dual Metal Surround Gate Junctionless Transistor (DMSGJLT) has been implemented with various high-k dielectric. The leakage current in the device is analysed in detail by obtaining the band structure for different high-k dielectric material. It is noticed that with increasing dielectric constant the device provides more resistance for the direct tunnelling of electron in off state. The gate oxide capacitance also shows 0.1 μF improvement with Hafnium Oxide (HfO2) than Silicon Oxide (SiO2). This paved the way for a better memory application when high-k dielectric is used. The Six Transistor (6T) Static Random Access Memory (SRAM) circuit implemented shows 41.4% improvement in read noise margin for HfO2 than SiO2. It also shows 37.49% improvement in write noise margin and 30.16% improvement in hold noise margin for HfO2 than SiO2.

  14. Circuit-Switched Memory Access in Photonic Interconnection Networks for High-Performance Embedded Computing

    Science.gov (United States)

    2010-07-22

    Memory Systems: Cadle. DRAM, Disk. Morgan Kaufmann , 2007. (2 1) A. Joshi, C. Ballen, Y.-J. Kwon. S . Beamcr, I. Shamim . K. Asano\\’ic, and V...COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d...PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION

  15. Towards High Density 3-D Memory in Diamond

    Science.gov (United States)

    Henshaw, Jacob; Dhomkar, Siddharth; Meriles, Carlos; Jayakumar, Harishankar

    The nitrogen-vacancy (NV) center in diamond is presently the focus of widespread attention for applications ranging from quantum information processing to nanoscale metrology. Of great utility is the ability to optically initialize the NV charge state, which has an immediate impact on the center's light emission properties. Here, we use two-color microscopy in NV-rich, type-1b diamond to demonstrate fluorescence-encoded long-term storage of classical information. As a proof of principle, we write, reset, and rewrite various patterns with 2-D binary bit density comparable to present DVD-ROM technology. The strong fluorescence signal originating from the diffraction-limited bit volume allows us to transition from binary to multi-valued encoding, which translates into a significant storage capacity boost. Finally, we show that our technique preserves information written on different planes of the diamond crystal and thus serves as a platform for three-dimensional storage. Substantial enhancement in the bit density could be achieved with the aid of super resolution microscopy techniques already employed to discriminate between NVs with sub-diffraction, nanometer accuracy, a regime where the storage capacity could exceed 1017 bytes/cm3 We acknowledge support from the National Science Foundation through Grant NSF-1314205.

  16. Spiers Memorial Lecture. Molecular mechanics and molecular electronics.

    Science.gov (United States)

    Beckman, Robert; Beverly, Kris; Boukai, Akram; Bunimovich, Yuri; Choi, Jang Wook; DeIonno, Erica; Green, Johnny; Johnston-Halperin, Ezekiel; Luo, Yi; Sheriff, Bonnie; Stoddart, Fraser; Heath, James R

    2006-01-01

    We describe our research into building integrated molecular electronics circuitry for a diverse set of functions, and with a focus on the fundamental scientific issues that surround this project. In particular, we discuss experiments aimed at understanding the function of bistable rotaxane molecular electronic switches by correlating the switching kinetics and ground state thermodynamic properties of those switches in various environments, ranging from the solution phase to a Langmuir monolayer of the switching molecules sandwiched between two electrodes. We discuss various devices, low bit-density memory circuits, and ultra-high density memory circuits that utilize the electrochemical switching characteristics of these molecules in conjunction with novel patterning methods. We also discuss interconnect schemes that are capable of bridging the micrometre to submicrometre length scales of conventional patterning approaches to the near-molecular length scales of the ultra-dense memory circuits. Finally, we discuss some of the challenges associated with fabricated ultra-dense molecular electronic integrated circuits.

  17. Modulation of sensorimotor circuits during retrieval of negative Autobiographical Memories: Exploring the impact of personality dimensions.

    Science.gov (United States)

    Mineo, Ludovico; Concerto, Carmen; Patel, Dhaval; Mayorga, Tyrone; Chusid, Eileen; Infortuna, Carmenrita; Aguglia, Eugenio; Sarraf, Yasmin; Battaglia, Fortunato

    2018-02-01

    Autobiographical Memory (AM) retrieval refers to recollection of experienced past events. Previous Transcranial Magnetic Stimulation (TMS) studies have shown that presentation of emotional negative stimuli affects human motor cortex excitability resulting in larger motor evoked potentials (MEPs). Up to date no TMS studies have been carried out in order to investigate the effect of personal memories with negative emotional value on corticospinal excitability. In this study we hypothesized that negative AM retrieval will modulate corticomotor excitability and sensorimotor integration as determined by TMS neurophysiological parameters. Furthermore, we investigated whether TMS responses during retrieval of negative AM are associated with specific personality traits. Twelve healthy subjects were asked to recall either a negative or a neutral AM across two different days in a randomized order. During this memory retrieval, the following TMS parameters were recorded: MEPs; Short- interval intracortical inhibition (SICI) and Intracortical facilitation (ICF); Short-latency afferent inhibition (SAI) and Long- latency afferent inhibition (LAI). Personality traits were assessed by using the Big Five scale. Statistical analysis was performed using factorial ANOVAs and multiple linear regression models. When compared to retrieval of neutral AM, recollection of negative AM induced a larger increase in MEP amplitude, an increase in ICF, and a decrease in SAI. The neuroticism personality trait was a significant predictor of the MEP amplitude increase during retrieval of negative AM. Altogether these results indicate that cortical excitability and sensorimotor integration are selectively modulated by the valence of AM. These results provide the first TMS evidence that the modulatory effect of the AM retrieval is associated with specific personality traits. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. NMDA and dopamine D1 receptors within NAc-shell regulate IEG proteins expression in reward circuit during cocaine memory reconsolidation.

    Science.gov (United States)

    Li, Y; Ge, S; Li, N; Chen, L; Zhang, S; Wang, J; Wu, H; Wang, X; Wang, X

    2016-02-19

    Reactivation of consolidated memory initiates a memory reconsolidation process, during which the reactivated memory is susceptible to strengthening, weakening or updating. Therefore, effective interference with the memory reconsolidation process is expected to be an important treatment for drug addiction. The nucleus accumbens (NAc) has been well recognized as a pathway component that can prevent drug relapse, although the mechanism underlying this function is poorly understood. We aimed to clarify the regulatory role of the NAc in the cocaine memory reconsolidation process, by examining the effect of applying different pharmacological interventions to the NAc on Zif 268 and Fos B expression in the entire reward circuit after cocaine memory reactivation. Through the cocaine-induced conditioned place preference (CPP) model, immunohistochemical and immunofluorescence staining for Zif 268 and Fos B were used to explore the functional activated brain nuclei after cocaine memory reactivation. Our results showed that the expression of Zif 268 and Fos B was commonly increased in the medial prefrontal cortex (mPFC), the infralimbic cortex (IL), the NAc-core, the NAc-shell, the hippocampus (CA1, CA2, and CA3 subregions), the amygdala, the ventral tegmental area (VTA), and the supramammillary nucleus (SuM) following memory reconsolidation, and Zif 268/Fos B co-expression was commonly observed (for Zif 268: 51-68%; for Fos B: 52-66%). Further, bilateral NAc-shell infusion of MK 801 and SCH 23390, but not raclopride or propranolol, prior to addictive memory reconsolidation, decreased Zif 268 and Fos B expression in the entire reward circuit, except for the amygdala, and effectively disturbed subsequent CPP-related behavior. In summary, N-methyl-d-aspartate (NMDA) and dopamine D1 receptors, but not dopamine D2 or β adrenergic receptors, within the NAc-shell, may regulate Zif 268 and Fos B expression in most brain nuclei of the reward circuit after cocaine memory reactivation

  19. Models for Experimental High Density Housing

    Science.gov (United States)

    Bradecki, Tomasz; Swoboda, Julia; Nowak, Katarzyna; Dziechciarz, Klaudia

    2017-10-01

    The article presents the effects of research on models of high density housing. The authors present urban projects for experimental high density housing estates. The design was based on research performed on 38 examples of similar housing in Poland that have been built after 2003. Some of the case studies show extreme density and that inspired the researchers to test individual virtual solutions that would answer the question: How far can we push the limits? The experimental housing projects show strengths and weaknesses of design driven only by such indexes as FAR (floor attenuation ratio - housing density) and DPH (dwellings per hectare). Although such projects are implemented, the authors believe that there are reasons for limits since high index values may be in contradiction to the optimum character of housing environment. Virtual models on virtual plots presented by the authors were oriented toward maximising the DPH index and DAI (dwellings area index) which is very often the main driver for developers. The authors also raise the question of sustainability of such solutions. The research was carried out in the URBAN model research group (Gliwice, Poland) that consists of academic researchers and architecture students. The models reflect architectural and urban regulations that are valid in Poland. Conclusions might be helpful for urban planners, urban designers, developers, architects and architecture students.

  20. Nanotechnology for Synthetic High Density Lipoproteins

    Science.gov (United States)

    Luthi, Andrea J.; Patel, Pinal C.; Ko, Caroline H.; Mutharasan, R. Kannan; Mirkin, Chad A.; Thaxton, C. Shad

    2014-01-01

    Atherosclerosis is the disease mechanism responsible for coronary heart disease (CHD), the leading cause of death worldwide. One strategy to combat atherosclerosis is to increase the amount of circulating high density lipoproteins (HDL), which transport cholesterol from peripheral tissues to the liver for excretion. The process, known as reverse cholesterol transport, is thought to be one of the main reasons for the significant inverse correlation observed between HDL blood levels and the development of CHD. This article highlights the most common strategies for treating atherosclerosis using HDL. We further detail potential treatment opportunities that utilize nanotechnology to increase the amount of HDL in circulation. The synthesis of biomimetic HDL nanostructures that replicate the chemical and physical properties of natural HDL provides novel materials for investigating the structure-function relationships of HDL and for potential new therapeutics to combat CHD. PMID:21087901

  1. Ground state of high-density matter

    Science.gov (United States)

    Copeland, ED; Kolb, Edward W.; Lee, Kimyeong

    1988-01-01

    It is shown that if an upper bound to the false vacuum energy of the electroweak Higgs potential is satisfied, the true ground state of high-density matter is not nuclear matter, or even strange-quark matter, but rather a non-topological soliton where the electroweak symmetry is exact and the fermions are massless. This possibility is examined in the standard SU(3) sub C tensor product SU(2) sub L tensor product U(1) sub Y model. The bound to the false vacuum energy is satisfied only for a narrow range of the Higgs boson masses in the minimal electroweak model (within about 10 eV of its minimum allowed value of 6.6 GeV) and a somewhat wider range for electroweak models with a non-minimal Higgs sector.

  2. Architecture and performance of radiation-hardened 64-bit SOS/MNOS memory

    International Nuclear Information System (INIS)

    Kliment, D.C.; Ronen, R.S.; Nielsen, R.L.; Seymour, R.N.; Splinter, M.R.

    1976-01-01

    This paper discusses the circuit architecture and performance of a nonvolatile 64-bit MNOS memory fabricated on silicon on sapphire (SOS). The circuit is a test vehicle designed to demonstrate the feasibility of a high-performance, high-density, radiation-hardened MNOS/SOS memory. The array is organized as 16 words by 4 bits and is fully decoded. It utilizes a two-(MNOS) transistor-per-bit cell and differential sensing scheme and is realized in PMOS static resistor load logic. The circuit was fabricated and tested as both a fast write random access memory (RAM) and an electrically alterable read only memory (EAROM) to demonstrate design and process flexibility. Discrete device parameters such as retention, circuit electrical characteristics, and tolerance to total dose and transient radiation are presented

  3. High Density Lipoprotein and it's Dysfunction.

    Science.gov (United States)

    Eren, Esin; Yilmaz, Necat; Aydin, Ozgur

    2012-01-01

    Plasma high-density lipoprotein cholesterol(HDL-C) levels do not predict functionality and composition of high-density lipoprotein(HDL). Traditionally, keeping levels of low-density lipoprotein cholesterol(LDL-C) down and HDL-C up have been the goal of patients to prevent atherosclerosis that can lead to coronary vascular disease(CVD). People think about the HDL present in their cholesterol test, but not about its functional capability. Up to 65% of cardiovascular death cannot be prevented by putative LDL-C lowering agents. It well explains the strong interest in HDL increasing strategies. However, recent studies have questioned the good in using drugs to increase level of HDL. While raising HDL is a theoretically attractive target, the optimal approach remains uncertain. The attention has turned to the quality, rather than the quantity, of HDL-C. An alternative to elevations in HDL involves strategies to enhance HDL functionality. The situation poses an opportunity for clinical chemists to take the lead in the development and validation of such biomarkers. The best known function of HDL is the capacity to promote cellular cholesterol efflux from peripheral cells and deliver cholesterol to the liver for excretion, thereby playing a key role in reverse cholesterol transport (RCT). The functions of HDL that have recently attracted attention include anti-inflammatory and anti-oxidant activities. High antioxidant and anti-inflammatory activities of HDL are associated with protection from CVD.This review addresses the current state of knowledge regarding assays of HDL functions and their relationship to CVD. HDL as a therapeutic target is the new frontier with huge potential for positive public health implications.

  4. Dynamics of neuronal circuits in addiction: reward, antireward, and emotional memory.

    Science.gov (United States)

    Koob, G F

    2009-05-01

    Drug addiction is conceptualized as chronic, relapsing compulsive use of drugs with significant dysregulation of brain hedonic systems. Compulsive drug use is accompanied by decreased function of brain substrates for drug positive reinforcement and recruitment of brain substrates mediating the negative reinforcement of motivational withdrawal. The neural substrates for motivational withdrawal ("dark side" of addiction) involve recruitment of elements of the extended amygdala and the brain stress systems, including corticotropin-releasing factor and norepinephrine. These changes, combined with decreased reward function, are hypothesized to persist in the form of an allostatic state that forms a powerful motivational background for relapse. Relapse also involves a key role for the basolateral amygdala in mediating the motivational effects of stimuli previously paired with drug seeking and drug motivational withdrawal. The basolateral amygdala has a key role in mediating emotional memories in general. The hypothesis argued here is that brain stress systems activated by the motivational consequences of drug withdrawal can not only form the basis for negative reinforcement that drives drug seeking, but also potentiate associative mechanisms that perpetuate the emotional state and help drive the allostatic state of addiction.

  5. Towards High-Frequency Shape Memory Alloy Actuators Incorporating Liquid Metal Energy Circuits

    Science.gov (United States)

    Hartl, Darren; Mingear, Jacob; Bielefeldt, Brent; Rohmer, John; Zamarripa, Jessica; Elwany, Alaa

    2017-12-01

    Large shape memory alloy (SMA) actuators are currently limited to applications with low cyclic actuation frequency requirements due to their generally poor heat transfer rates. This limitation can be overcome through the use of distributed body heating methods such as induction heating or by accelerated cooling methods such as forced convection in internal cooling channels. In this work, a monolithic SMA beam actuator containing liquid gallium-indium alloy-filled channels is fabricated through additive manufacturing. These liquid metal channels enable a novel multi-physical thermal control system, allowing for increased heating and cooling rates to facilitate an increased cyclic actuation frequency. Liquid metal flowing in the channels performs the dual tasks of inductively heating the surrounding SMA material and then actively cooling the SMA via forced internal fluid convection. A coupled thermoelectric model, implemented in COMSOL, predicts a possible fivefold increase in the cyclic actuation frequency due to these increased thermal transfer rates when compared to conventional SMA forms having external heating coils and being externally cooled via forced convection. The first ever experimental prototype SMA actuator of this type is described and, even at much lower flow rates, is shown to exhibit a decrease in cooling time of 40.9%.

  6. Impact of multiplexed reading scheme on nanocrossbar memristor memory's scalability

    International Nuclear Information System (INIS)

    Zhu Xuan; Tang Yu-Hua; Wu Jun-Jie; Yi Xun; Wu Chun-Qing

    2014-01-01

    Nanocrossbar is a potential memory architecture to integrate memristor to achieve large scale and high density memory. However, based on the currently widely-adopted parallel reading scheme, scalability of the nanocrossbar memory is limited, since the overhead of the reading circuits is in proportion with the size of the nanocrossbar component. In this paper, a multiplexed reading scheme is adopted as the foundation of the discussion. Through HSPICE simulation, we reanalyze scalability of the nanocrossbar memristor memory by investigating the impact of various circuit parameters on the output voltage swing as the memory scales to larger size. We find that multiplexed reading maintains sufficient noise margin in large size nanocrossbar memristor memory. In order to improve the scalability of the memory, memristors with nonlinear I—V characteristics and high LRS (low resistive state) resistance should be adopted. (interdisciplinary physics and related areas of science and technology)

  7. The medial prefrontal cortex-lateral entorhinal cortex circuit is essential for episodic-like memory and associative object-recognition.

    Science.gov (United States)

    Chao, Owen Y; Huston, Joseph P; Li, Jay-Shake; Wang, An-Li; de Souza Silva, Maria A

    2016-05-01

    The prefrontal cortex directly projects to the lateral entorhinal cortex (LEC), an important substrate for engaging item-associated information and relaying the information to the hippocampus. Here we ask to what extent the communication between the prefrontal cortex and LEC is critically involved in the processing of episodic-like memory. We applied a disconnection procedure to test whether the interaction between the medial prefrontal cortex (mPFC) and LEC is essential for the expression of recognition memory. It was found that male rats that received unilateral NMDA lesions of the mPFC and LEC in the same hemisphere, exhibited intact episodic-like (what-where-when) and object-recognition memories. When these lesions were placed in the opposite hemispheres (disconnection), episodic-like and associative memories for object identity, location and context were impaired. However, the disconnection did not impair the components of episodic memory, namely memory for novel object (what), object place (where) and temporal order (when), per se. Thus, the present findings suggest that the mPFC and LEC are a critical part of a neural circuit that underlies episodic-like and associative object-recognition memory. © 2015 Wiley Periodicals, Inc.

  8. Analysis of SEL on Commercial SRAM Memories and Mixed-Field Characterization of a Latchup Detection Circuit for LEO Space Applications

    Science.gov (United States)

    Secondo, R.; Alía, R. Garcia; Peronnard, P.; Brugger, M.; Masi, A.; Danzeca, S.; Merlenghi, A.; Vaillé, J.-R.; Dusseau, L.

    2017-08-01

    A single event latchup (SEL) experiment based on commercial static random access memory (SRAM) memories has recently been proposed in the framework of the European Organization for Nuclear Research (CERN) Latchup Experiment and Student Satellite nanosatellite low Earth orbit (LEO) space mission. SEL characterization of three commercial SRAM memories has been carried out at the Paul Scherrer Institut (PSI) facility, using monoenergetic focused proton beams and different acquisition setups. The best target candidate was selected and a circuit for SEL detection has been proposed and tested at CERN, in the CERN High Energy AcceleRator Mixed-field facility (CHARM). Experimental results were carried out at test locations representative of the LEO environment, thus providing a full characterization of the SRAM cross sections, together with the analysis of the single-event effect and total ionizing dose of the latchup detection circuit in relation to the particle spectra expected during mission. The setups used for SEL monitoring are described, and details of the proposed circuit components and topology are presented. Experimental results obtained both at PSI and at CHARM facilities are discussed.

  9. High-density lipoprotein cholesterol: How High

    Directory of Open Access Journals (Sweden)

    G Rajagopal

    2012-01-01

    Full Text Available The high-density lipoprotein cholesterol (HDL-C is considered anti-atherogenic good cholesterol. It is involved in reverse transport of lipids. Epidemiological studies have found inverse relationship of HDL-C and coronary heart disease (CHD risk. When grouped according to HDL-C, subjects having HDL-C more than 60 mg/dL had lesser risk of CHD than those having HDL-C of 40-60 mg/dL, who in turn had lesser risk than those who had HDL-C less than 40 mg/dL. No upper limit for beneficial effect of HDL-C on CHD risk has been identified. The goals of treating patients with low HDL-C have not been firmly established. Though many drugs are known to improve HDL-C concentration, statins are proven to improve CHD risk and mortality. Cholesteryl ester transfer protein (CETP is involved in metabolism of HDL-C and its inhibitors are actively being screened for clinical utility. However, final answer is still awaited on CETP-inhibitors.

  10. High-density hybrid interconnect methodologies

    International Nuclear Information System (INIS)

    John, J.; Zimmermann, L.; Moor, P.De; Hoof, C.Van

    2003-01-01

    Full text: The presentation gives an overview of the state-of-the-art of hybrid integration and in particular the IMEC technological approaches that will be able to address future hybrid detector needs. The dense hybrid flip-chip integration of an array of detectors and its dedicated readout electronics can be achieved with a variety of solderbump techniques such as pure Indium or Indium alloys, Ph-In, Ni/PbSn, but also conducting polymers... Particularly for cooled applications or ultra-high density applications, Indium solderbump technology (electroplated or evaporated) is the method of choice. The state-of-the-art of solderbump technologies that are to a high degree independent of the underlying detector material will be presented and examples of interconnect densities between 5x1E4cm-2 and 1x1E6 cm-2 will be demonstrated. For several classes of detectors, flip-chip integration is not allowed since the detectors have to be illuminated from the top. This applies to image sensors for EUV applications such as GaN/AlGaN based detectors and to MEMS-based sensors. In such cases, the only viable interconnection method has to be through the (thinned) detector wafer followed by a solderbump-based integration. The approaches for dense and ultra-dense through-the-wafer interconnect 'vias' will be presented and wafer thinning approaches will be shown

  11. HIGH DENSITY QCD WITH HEAVY-IONS

    CERN Multimedia

    The Addendum 1 to Volume 2 of the CMS Physics TDR has been published The Heavy-Ion analysis group completed the writing of a TDR summarizing the CMS plans in using heavy ion collisions to study high density QCD. The document was submitted to the LHCC in March and presented in the Open Session of the LHCC on May 9th. The study of heavy-ion physics at the LHC is promising to be very exciting. LHC will open a new energy frontier in ultra-relativistic heavy-ion physics. The collision energy of heavy nuclei at sNN = 5.5 TeV will be thirty times larger than what is presently available at RHIC. We will certainly probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research programme is to study the fundamental theory of the strong interaction - Quantum Chromodynamics (QCD) - in extreme conditions of temperature, density and parton momentum fraction (low-x). Such studies, with impressive experimental and theoretical advances in recent years thanks to the wealth of high-qua...

  12. High-density oxidized porous silicon

    International Nuclear Information System (INIS)

    Gharbi, Ahmed; Souifi, Abdelkader; Remaki, Boudjemaa; Halimaoui, Aomar; Bensahel, Daniel

    2012-01-01

    We have studied oxidized porous silicon (OPS) properties using Fourier transform infraRed (FTIR) spectroscopy and capacitance–voltage C–V measurements. We report the first experimental determination of the optimum porosity allowing the elaboration of high-density OPS insulators. This is an important contribution to the research of thick integrated electrical insulators on porous silicon based on an optimized process ensuring dielectric quality (complete oxidation) and mechanical and chemical reliability (no residual pores or silicon crystallites). Through the measurement of the refractive indexes of the porous silicon (PS) layer before and after oxidation, one can determine the structural composition of the OPS material in silicon, air and silica. We have experimentally demonstrated that a porosity approaching 56% of the as-prepared PS layer is required to ensure a complete oxidation of PS without residual silicon crystallites and with minimum porosity. The effective dielectric constant values of OPS materials determined from capacitance–voltage C–V measurements are discussed and compared to FTIR results predictions. (paper)

  13. Cooling of high-density and power electronics by means of heat pipes

    International Nuclear Information System (INIS)

    Hubbeling, L.

    1980-06-01

    This report describes how heat pipes can be used for cooling modern electronic equipment, with numerous advantages over air-cooled systems. A brief review of heat-pipe properties is given, with a detailed description of a functioning prototype. This is a single-width CAMAC unit containing high-density electronic circuits cooled by three heat pipes, and allowing a dissipation of over 120 W instead of the normal maximum of 20 W. (orig.)

  14. Analog-to-digital conversion using custom CMOS analog memory for the EOS time projection chamber

    International Nuclear Information System (INIS)

    Lee, K.L.; Arthur, A.A.; Jones, R.W.; Matis, H.S.; Nakamura, M.; Kleinfelder, S.A.; Ritter, H.G.; Wienman, H.H.

    1990-01-01

    This paper describes the multiplexing scheme of custom CMOS analog memory integrated circuits, 16 channels x 256 cells, into analog to digital converters (ADC's) to handle 15,360 signal channels of a time projection, chamber detector system. Primary requirements of this system are high density, low power and large dynamic range. The analog memory device multiplexing scheme was designed to digitize the information stored in the memory cells. The digitization time of the ADC's and the settling times for the memory unit were carefully interleaved to optimize the performance and timing during the multiplexing operation. This kept the total number of ADC's, a costly and power dissipative component, to an acceptable minimum

  15. Selective post-training time window for memory consolidation interference of cannabidiol into the prefrontal cortex: Reduced dopaminergic modulation and immediate gene expression in limbic circuits.

    Science.gov (United States)

    Rossignoli, Matheus Teixeira; Lopes-Aguiar, Cleiton; Ruggiero, Rafael Naime; Do Val da Silva, Raquel Araujo; Bueno-Junior, Lezio Soares; Kandratavicius, Ludmyla; Peixoto-Santos, José Eduardo; Crippa, José Alexandre; Cecilio Hallak, Jaime Eduardo; Zuardi, Antonio Waldo; Szawka, Raphael Escorsim; Anselmo-Franci, Janete; Leite, João Pereira; Romcy-Pereira, Rodrigo Neves

    2017-05-14

    The prefrontal cortex (PFC), amygdala and hippocampus display a coordinated activity during acquisition of associative fear memories. Evidence indicates that PFC engagement in aversive memory formation does not progress linearly as previously thought. Instead, it seems to be recruited at specific time windows after memory acquisition, which has implications for the treatment of post-traumatic stress disorders. Cannabidiol (CBD), the major non-psychotomimetic phytocannabinoid of the Cannabis sativa plant, is known to modulate contextual fear memory acquisition in rodents. However, it is still not clear how CBD interferes with PFC-dependent processes during post-training memory consolidation. Here, we tested whether intra-PFC infusions of CBD immediately after or 5h following contextual fear conditioning was able to interfere with memory consolidation. Neurochemical and cellular correlates of the CBD treatment were evaluated by the quantification of extracellular levels of dopamine (DA), serotonin, and their metabolites in the PFC and by measuring the cellular expression of activity-dependent transcription factors in cortical and limbic regions. Our results indicate that bilateral intra-PFC CBD infusion impaired contextual fear memory consolidation when applied 5h after conditioning, but had no effect when applied immediately after it. This effect was associated with a reduction in DA turnover in the PFC following retrieval 5days after training. We also observed that post-conditioning infusion of CBD reduced c-fos and zif-268 protein expression in the hippocampus, PFC, and thalamus. Our findings support that CBD interferes with contextual fear memory consolidation by reducing PFC influence on cortico-limbic circuits. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Memory

    Science.gov (United States)

    ... it has to decide what is worth remembering. Memory is the process of storing and then remembering this information. There are different types of memory. Short-term memory stores information for a few ...

  17. Improved GAMMA 10 tandem mirror confinement in high density plasma

    International Nuclear Information System (INIS)

    Yatsu, K.; Cho, T.; Higaki, H.; Hirata, M.; Hojo, H.; Ichimura, M.; Ishii, K.; Ishimoto, Y.; Itakura, A.; Katanuma, I.; Kohagura, J.; Minami, R.; Nakashima, Y.; Numakura, T.; Saito, T.; Saosaki, S.; Takemura, Y.; Tatematsu, Y.; Yoshida, M.; Yoshikawa, M.

    2003-01-01

    GAMMA 10 experiments have advanced in high density experiments after the last IAEA fusion energy conference in 2000 where we reported the production of the high density plasma through use of ion cyclotron range of frequency heating at a high harmonic frequency and neutral beam injection in the anchor cells. However, the diamagnetic signal of the plasma decreased when electron cyclotron resonance heating was applied for the potential formation. Recently a high density plasma has been obtained without degradation of the diamagnetic signal and with much improved reproducibility than before. The high density plasma was attained through adjustment of the spacing of the conducting plates installed in the anchor transition regions. The potential confinement of the plasma has been extensively studied. Dependences of the ion confinement time, ion-energy confinement time and plasma confining potential on plasma density were obtained for the first time in the high density region up to a density of 4x10 18 m -3 . (author)

  18. Molecular and Neuronal Plasticity Mechanisms in the Amygdala-Prefrontal Cortical Circuit: Implications for Opiate Addiction Memory Formation

    Directory of Open Access Journals (Sweden)

    Laura G Rosen

    2015-11-01

    Full Text Available The persistence of associative memories linked to the rewarding properties of drugs of abuse is a core underlying feature of the addiction process. Opiate class drugs in particular, possess potent euphorigenic effects which, when linked to environmental cues, can produce drug-related ‘trigger’ memories that may persist for lengthy periods of time, even during abstinence, in both humans and other animals. Furthermore, the transitional switch from the drug-naïve, non-dependent state to states of dependence and withdrawal, represents a critical boundary between distinct neuronal and molecular substrates associated with opiate-reward memory formation. Identifying the functional molecular and neuronal mechanisms related to the acquisition, consolidation, recall and extinction phases of opiate-related reward memories is critical for understanding, and potentially reversing, addiction-related memory plasticity characteristic of compulsive drug-seeking behaviors. The mammalian prefrontal cortex (PFC and basolateral nucleus of the amygdala (BLA share important functional and anatomical connections that are involved importantly in the processing of associative memories linked to drug reward. In addition, both regions share interconnections with the mesolimbic pathway’s ventral tegmental area (VTA and nucleus accumbens (NAc and can modulate dopamine (DA transmission and neuronal activity associated with drug-related DAergic signaling dynamics. In this review, we will summarize research from both human and animal modelling studies highlighting the importance of neuronal and molecular plasticity mechanisms within this circuitry during critical phases of opiate addiction-related learning and memory processing. Specifically, we will focus on two molecular signaling pathways known to be involved in both drug-related neuroadaptations and in memory-related plasticity mechanisms; the extracellular-signal-regulated kinase system (ERK and the Ca2+/calmodulin

  19. Phenomenology of high density disruptions in the TFTR tokamak

    International Nuclear Information System (INIS)

    Fredrickson, E.D.; McGuire, K.M.; Bell, M.G.

    1993-01-01

    Studies of high density disruptions on TFTR, including a comparison of minor and major disruptions at high density, provide important new information regarding the nature of the disruption mechanism. Further, for the first time, an (m,n)=(1,1) 'cold bubble' precursor to high density disruptions has been experimentally observed in the electron temperature profile. The precursor to major disruptions resembles the 'vacuum bubble' model of disruptions first proposed by B.B. Kadomtsev and O.P. Pogutse (Sov. Phys. - JETP 38 (1974) 283). (author). Letter-to-the-editor. 25 refs, 3 figs

  20. Mapping of olfactory memory circuits: region-specific c-fos activation after odor-reward associative learning or after its retrieval.

    Science.gov (United States)

    Tronel, Sophie; Sara, Susan J

    2002-01-01

    Although there is growing knowledge about intracellular mechanisms underlying neuronal plasticity and memory consolidation and reconsolidation after retrieval, information concerning the interaction among brain areas during formation and retrieval of memory is relatively sparse and fragmented. Addressing this question requires simultaneous monitoring of activity in multiple brain regions during learning, the post-acquisition consolidation period, and retrieval and subsequent reconsolidation. Immunoreaction to the immediate early gene c-fos is a powerful tool to mark neuronal activation of specific populations of neurons. Using this method, we are able to report, for the first time, post-training activation of a network of closely related brain regions, particularly in the frontal cortex and the basolateral amygdala (BLA), that is specific to the learning of an odor-reward association. On the other hand, retrieval of a well-established associative memory trace does not seem to differentially activate the same regions. The amygdala, in particular, is not engaged after retrieval, whereas the lateral habenula (LHab) shows strong activation that is restricted to animals having previously learned the association. Although intracellular mechanisms may be similar during consolidation and reconsolidation, this study indicates that different brain circuits are involved in the two processes, at least with respect to a rapidly learned olfactory task.

  1. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  2. High regression rate, high density hybrid fuels, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR program will investigate high energy density novel nanofuels combined with high density binders for use with an N2O oxidizer. Terves has developed...

  3. The Influence of Decreased Levels of High Density Lipoprotein ...

    African Journals Online (AJOL)

    very low density lipoprotein cholesterol, and triglyceride were assayed. ... Abiodun and Gwarzo: Association of high density lipoprotein cholesterol with haemolysis in sickle cell disease ... analyses were carried out to determine the correlation.

  4. High density UO2 powder preparation for HWR fuel

    International Nuclear Information System (INIS)

    Hwang, S. T.; Chang, I. S.; Choi, Y. D.; Cho, B. R.; Kwon, S. W.; Kim, B. H.; Moon, B. H.; Kim, S. D.; Phyu, K. M.; Lee, K. A.

    1992-01-01

    The objective of this project is to study on the preparation of method high density UO 2 powder for HWR Fuel. Accordingly, it is necessary to character ize the AUC processed UO 2 powder and to search method for the preparation of high density UO 2 powder for HWR Fuel. Therefore, it is expected that the results of this study can effect the producing of AUC processed UO 2 powder having sinterability. (Author)

  5. The high density effects in the Drell-Yan process

    International Nuclear Information System (INIS)

    Betemps, M.A.; Gay Ducati, M.B.; Ayala Filho, A.L.

    2003-01-01

    The high density effects in the Drell-Yan process (q q-bar → γ * →l + l - ) are investigated for pA collisions at RHIC and LHC energies. In particular, we use a set of nuclear parton distributions that describes the present nuclear eA and pA data in the DGLAP approach including the high density effects introduced in the perturbative Glauber-Mueller approach. (author)

  6. Age-related individual variability in memory performance is associated with amygdala-hippocampal circuit function and emotional pattern separation

    Science.gov (United States)

    Leal, Stephanie L.; Noche, Jessica A.; Murray, Elizabeth A.; Yassa, Michael A.

    2018-01-01

    While aging is generally associated with episodic memory decline, not all older adults exhibit memory loss. Furthermore, emotional memories are not subject to the same extent of forgetting and appear preserved in aging. We conducted high-resolution fMRI during a task involving pattern separation of emotional information in older adults with and without age-related memory impairment (characterized by performance on a word-list learning task: low performers: LP vs. high performers: HP). We found signals consistent with emotional pattern separation in hippocampal dentate (DG)/CA3 in HP but not in LP individuals, suggesting a deficit in emotional pattern separation. During false recognition, we found increased DG/CA3 activity in LP individuals, suggesting that hyperactivity may be associated with overgeneralization. We additionally observed a selective deficit in basolateral amygdala—lateral entorhinal cortex—DG/CA3 functional connectivity in LP individuals during pattern separation of negative information. During negative false recognition, LP individuals showed increased medial temporal lobe functional connectivity, consistent with overgeneralization. Overall, these results suggest a novel mechanistic account of individual differences in emotional memory alterations exhibited in aging. PMID:27723500

  7. Age-related individual variability in memory performance is associated with amygdala-hippocampal circuit function and emotional pattern separation.

    Science.gov (United States)

    Leal, Stephanie L; Noche, Jessica A; Murray, Elizabeth A; Yassa, Michael A

    2017-01-01

    While aging is generally associated with episodic memory decline, not all older adults exhibit memory loss. Furthermore, emotional memories are not subject to the same extent of forgetting and appear preserved in aging. We conducted high-resolution fMRI during a task involving pattern separation of emotional information in older adults with and without age-related memory impairment (characterized by performance on a word-list learning task: low performers: LP vs. high performers: HP). We found signals consistent with emotional pattern separation in hippocampal dentate (DG)/CA3 in HP but not in LP individuals, suggesting a deficit in emotional pattern separation. During false recognition, we found increased DG/CA3 activity in LP individuals, suggesting that hyperactivity may be associated with overgeneralization. We additionally observed a selective deficit in basolateral amygdala-lateral entorhinal cortex-DG/CA3 functional connectivity in LP individuals during pattern separation of negative information. During negative false recognition, LP individuals showed increased medial temporal lobe functional connectivity, consistent with overgeneralization. Overall, these results suggest a novel mechanistic account of individual differences in emotional memory alterations exhibited in aging. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Working memory circuit as a function of increasing age in healthy adolescence: A systematic review and meta-analyses.

    Science.gov (United States)

    Andre, Julia; Picchioni, Marco; Zhang, Ruibin; Toulopoulou, Timothea

    2016-01-01

    Working memory ability matures through puberty and early adulthood. Deficits in working memory are linked to the risk of onset of neurodevelopmental disorders such as schizophrenia, and there is a significant temporal overlap between the peak of first episode psychosis risk and working memory maturation. In order to characterize the normal working memory functional maturation process through this critical phase of cognitive development we conducted a systematic review and coordinate based meta-analyses of all the available primary functional magnetic resonance imaging studies (n = 382) that mapped WM function in healthy adolescents (10-17 years) and young adults (18-30 years). Activation Likelihood Estimation analyses across all WM tasks revealed increased activation with increasing subject age in the middle frontal gyrus (BA6) bilaterally, the left middle frontal gyrus (BA10), the left precuneus and left inferior parietal gyri (BA7; 40). Decreased activation with increasing age was found in the right superior frontal (BA8), left junction of postcentral and inferior parietal (BA3/40), and left limbic cingulate gyrus (BA31). These results suggest that brain activation during adolescence increased with age principally in higher order cortices, part of the core working memory network, while reductions were detected in more diffuse and potentially more immature neural networks. Understanding the process by which the brain and its cognitive functions mature through healthy adulthood may provide us with new clues to understanding the vulnerability to neurodevelopmental disorders.

  9. Working memory circuit as a function of increasing age in healthy adolescence: A systematic review and meta-analyses

    Directory of Open Access Journals (Sweden)

    Julia Andre

    2016-01-01

    Full Text Available Working memory ability matures through puberty and early adulthood. Deficits in working memory are linked to the risk of onset of neurodevelopmental disorders such as schizophrenia, and there is a significant temporal overlap between the peak of first episode psychosis risk and working memory maturation. In order to characterize the normal working memory functional maturation process through this critical phase of cognitive development we conducted a systematic review and coordinate based meta-analyses of all the available primary functional magnetic resonance imaging studies (n = 382 that mapped WM function in healthy adolescents (10–17 years and young adults (18–30 years. Activation Likelihood Estimation analyses across all WM tasks revealed increased activation with increasing subject age in the middle frontal gyrus (BA6 bilaterally, the left middle frontal gyrus (BA10, the left precuneus and left inferior parietal gyri (BA7; 40. Decreased activation with increasing age was found in the right superior frontal (BA8, left junction of postcentral and inferior parietal (BA3/40, and left limbic cingulate gyrus (BA31. These results suggest that brain activation during adolescence increased with age principally in higher order cortices, part of the core working memory network, while reductions were detected in more diffuse and potentially more immature neural networks. Understanding the process by which the brain and its cognitive functions mature through healthy adulthood may provide us with new clues to understanding the vulnerability to neurodevelopmental disorders.

  10. The BDNF Val66Met polymorphism has opposite effects on memory circuits of multiple sclerosis patients and controls.

    Directory of Open Access Journals (Sweden)

    Francesco Fera

    Full Text Available Episodic memory deficits are frequent symptoms in Multiple Sclerosis and have been associated with dysfunctions of the hippocampus, a key region for learning. However, it is unclear whether genetic factors that influence neural plasticity modulate episodic memory in MS. We thus studied how the Brain Derived Neurotrophic Factor Val(66Met genotype, a common polymorphism influencing the hippocampal function in healthy controls, impacted on brain networks underlying episodic memory in patients with Multiple Sclerosis. Functional magnetic resonance imaging was used to assess how the Brain Derived Neurotrophic Factor Val(66Met polymorphism modulated brain regional activity and functional connectivity in 26 cognitively unimpaired Multiple Sclerosis patients and 25 age- and education-matched healthy controls while performing an episodic memory task that included encoding and retrieving visual scenes. We found a highly significant group by genotype interaction in the left posterior hippocampus, bilateral parahippocampus, and left posterior cingulate cortex. In particular, Multiple Sclerosis patients homozygous for the Val(66 allele, relative to Met(66 carriers, showed greater brain responses during both encoding and retrieval while the opposite was true for healthy controls. Furthermore, a robust group by genotype by task interaction was detected for the functional connectivity between the left posterior hippocampus and the ipsilateral posterior cingulate cortex. Here, greater hippocampus-posterior cingulate cortex connectivity was observed in Multiple Sclerosis Met(66 carriers relative to Val(66 homozygous during retrieval (but not encoding while, again, the reverse was true for healthy controls. The Val(66Met polymorphism has opposite effects on hippocampal circuitry underlying episodic memory in Multiple Sclerosis patients and healthy controls. Enhancing the knowledge of how genetic factors influence cognitive functions may improve the clinical

  11. The test of VLSI circuits

    Science.gov (United States)

    Baviere, Ph.

    Tests which have proven effective for evaluating VLSI circuits for space applications are described. It is recommended that circuits be examined after each manfacturing step to gain fast feedback on inadequacies in the production system. Data from failure modes which occur during operational lifetimes of circuits also permit redefinition of the manufacturing and quality control process to eliminate the defects identified. Other tests include determination of the operational envelope of the circuits, examination of the circuit response to controlled inputs, and the performance and functional speeds of ROM and RAM memories. Finally, it is desirable that all new circuits be designed with testing in mind.

  12. LDRD Final Report - Investigations of the impact of the process integration of deposited magnetic films for magnetic memory technologies on radiation hardened CMOS devices and circuits - LDRD Project (FY99)

    International Nuclear Information System (INIS)

    Myers, David R.; Jessing, Jeffrey R.; Spahn, Olga B.; Shaneyfelt, Marty R.

    2000-01-01

    This project represented a coordinated LLNL-SNL collaboration to investigate the feasibility of developing radiation-hardened magnetic non-volatile memories using giant magnetoresistance (GMR) materials. The intent of this limited-duration study was to investigate whether giant magnetoresistance (GMR) materials similar to those used for magnetic tunnel junctions (MTJs) were process compatible with functioning CMOS circuits. Sandia's work on this project demonstrated that deposition of GMR materials did not affect the operation nor the radiation hardness of Sandia's rad-hard CMOS technology, nor did the integration of GMR materials and exposure to ionizing radiation affect the magnetic properties of the GMR films. Thus, following deposition of GMR films on rad-hard integrated circuits, both the circuits and the films survived ionizing radiation levels consistent with DOE mission requirements. Furthermore, Sandia developed techniques to pattern deposited GMR films without degrading the completed integrated circuits upon which they were deposited. The present feasibility study demonstrated all the necessary processing elements to allow fabrication of the non-volatile memory elements onto an existing CMOS chip, and even allow the use of embedded (on-chip) non-volatile memories for system-on-a-chip applications, even in demanding radiation environments. However, funding agencies DTRA, AIM, and DARPA did not have any funds available to support the required follow-on technology development projects that would have been required to develop functioning prototype circuits, nor were such funds available from LDRD nor from other DOE program funds

  13. A hybrid magnetic/complementary metal oxide semiconductor three-context memory bit cell for non-volatile circuit design

    International Nuclear Information System (INIS)

    Jovanović, B.; Brum, R. M.; Torres, L.

    2014-01-01

    After decades of continued scaling to the beat of Moore's law, it now appears that conventional silicon based devices are approaching their physical limits. In today's deep-submicron nodes, a number of short-channel and quantum effects are emerging that affect the manufacturing process, as well as, the functionality of the microelectronic systems-on-chip. Spintronics devices that exploit both the intrinsic spin of the electron and its associated magnetic moment, in addition to its fundamental electronic charge, are promising solutions to circumvent these scaling threats. Being compatible with the CMOS technology, such devices offer a promising synergy of radiation immunity, infinite endurance, non-volatility, increased density, etc. In this paper, we present a hybrid (magnetic/CMOS) cell that is able to store and process data both electrically and magnetically. The cell is based on perpendicular spin-transfer torque magnetic tunnel junctions (STT-MTJs) and is suitable for use in magnetic random access memories and reprogrammable computing (non-volatile registers, processor cache memories, magnetic field-programmable gate arrays, etc). To demonstrate the potential our hybrid cell, we physically implemented a small hybrid memory block using 45 nm × 45 nm round MTJs for the magnetic part and 28 nm fully depleted silicon on insulator (FD-SOI) technology for the CMOS part. We also report the cells measured performances in terms of area, robustness, read/write speed and energy consumption

  14. A hybrid magnetic/complementary metal oxide semiconductor three-context memory bit cell for non-volatile circuit design

    Energy Technology Data Exchange (ETDEWEB)

    Jovanović, B., E-mail: bojan.jovanovic@lirmm.fr, E-mail: lionel.torres@lirmm.fr; Brum, R. M.; Torres, L. [LIRMM—University of Montpellier 2/UMR CNRS 5506, 161 Rue Ada, 34095 Montpellier (France)

    2014-04-07

    After decades of continued scaling to the beat of Moore's law, it now appears that conventional silicon based devices are approaching their physical limits. In today's deep-submicron nodes, a number of short-channel and quantum effects are emerging that affect the manufacturing process, as well as, the functionality of the microelectronic systems-on-chip. Spintronics devices that exploit both the intrinsic spin of the electron and its associated magnetic moment, in addition to its fundamental electronic charge, are promising solutions to circumvent these scaling threats. Being compatible with the CMOS technology, such devices offer a promising synergy of radiation immunity, infinite endurance, non-volatility, increased density, etc. In this paper, we present a hybrid (magnetic/CMOS) cell that is able to store and process data both electrically and magnetically. The cell is based on perpendicular spin-transfer torque magnetic tunnel junctions (STT-MTJs) and is suitable for use in magnetic random access memories and reprogrammable computing (non-volatile registers, processor cache memories, magnetic field-programmable gate arrays, etc). To demonstrate the potential our hybrid cell, we physically implemented a small hybrid memory block using 45 nm × 45 nm round MTJs for the magnetic part and 28 nm fully depleted silicon on insulator (FD-SOI) technology for the CMOS part. We also report the cells measured performances in terms of area, robustness, read/write speed and energy consumption.

  15. High-density-plasma diagnostics in magnetic-confinement fusion

    International Nuclear Information System (INIS)

    Jahoda, F.C.

    1982-01-01

    The lectures will begin by defining high density in the context of magnetic confinement fusion research and listing some alternative reactor concepts, ranging from n/sub e/ approx. 2 x 10 14 cm -3 to several orders of magnitude greater, that offer potential advantages over the main-line, n/sub e/ approx. 1 x 10 14 cm -3 , Tokamak reactor designs. The high density scalings of several major diagnostic techniques, some favorable and some disadvantageous, will be discussed. Special emphasis will be given to interferometric methods, both electronic and photographic, for which integral n/sub e/dl measurements and associated techniques are accessible with low wavelength lasers. Reactor relevant experience from higher density, smaller dimension devices exists. High density implies high β, which implies economies of scale. The specialized features of high β diagnostics will be discussed

  16. Tools for probing local circuits: high-density silicon probes combined with optogenetics

    Science.gov (United States)

    Buzsáki, György; Stark, Eran; Berényi, Antal; Khodagholy, Dion; Kipke, Daryl R.; Yoon, Euisik; Wise, Kensall

    2015-01-01

    To understand how function arises from the interactions between neurons, it is necessary to use methods that allow the monitoring of brain activity at the single-neuron, single-spike level and the targeted manipulation of the diverse neuron types selectively in a closed-loop manner. Large-scale recordings of neuronal spiking combined with optogenetic perturbation of identified individual neurons has emerged as a suitable method for such tasks in behaving animals. To fully exploit the potential power of these methods, multiple steps of technical innovation are needed. We highlight the current state-of-the-art in electrophysiological recording methods, combined with optogenetics, and discuss directions for progress. In addition, we point to areas where rapid development is in progress and discuss topics where near-term improvements are possible and needed. PMID:25856489

  17. Road work on memory lane--functional and structural alterations to the learning and memory circuit in adults born very preterm.

    Science.gov (United States)

    Salvan, Piergiorgio; Froudist Walsh, Seán; Allin, Matthew P G; Walshe, Muriel; Murray, Robin M; Bhattacharyya, Sagnik; McGuire, Philip K; Williams, Steven C R; Nosarti, Chiara

    2014-11-15

    Very preterm (VPT) birth is considered a risk factor not only for neurological impairment, but also for reduced function in several cognitive domains in childhood and later in life. Individuals who were born VPT are more likely to demonstrate learning and memory difficulties compared to term-born controls. These problems contribute to more VPT-born children repeating grades and underachieving in school. This, in turn, affects their prospects in adult life. Here we aimed to 1) study how the VPT-born adult brain functionally recruited specific areas during learning, i.e. encoding and recall across four repeated blocks of verbal stimuli, and to investigate how these patterns of activation differed from term-born subjects; and 2) probe the microstructural differences of white-matter tracts connecting these areas to other parts of the learning and memory network. To investigate these functional-structural relationships we analyzed functional and diffusion-weighted MRI. Functional-MRI and a verbal paired associate learning (VPAL) task were used to extract Blood Oxygenation Level Dependent (BOLD) activity in 21 VPT-born adults (memory network, including anterior cingulate and caudate body during encoding and thalamus/parahippocampal gyrus during cued recall. Altered activation in thalamus/parahippocampal gyrus may be explained by reduced connections between these areas and the hippocampus, which may be a direct consequence of neonatal hypoxic/ischemic injury. These results could reflect the effect of adaptive plastic processes associated with high-order cognitive functions, at least when the cognitive load remains relatively low, as ex-preterm young adults displayed unimpaired performance in completing the verbal paired associate learning task. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. BCS Theory of Hadronic Matter at High Densities

    DEFF Research Database (Denmark)

    Bohr, Henrik; Panda, Prafulla K.; Providencia, Constanca

    2012-01-01

    The equilibrium between the so-called 2SC and CFL phases of strange quark matter at high densities is investigated in the framework of a simple schematic model of the NJL type. Equal densities are assumed for quarks u, d and s. The 2SC phase is here described by a color-flavor symmetric state, in...

  19. Antioxidant activity of high-density lipoprotein (HDL) using different ...

    African Journals Online (AJOL)

    HDL is a potent antioxidant in terms of inhibition of lipid peroxidation, ROS production and LDL oxidation. These may to some extent add to the antiatherogenic beyond reverse-cholesterol transport properties of HDL. Keywords: high-density lipoprotein; reverse cholesterol transport; apolipoprotein A1; antioxidant; in vitro.

  20. Morphodynamics of supercritical high-density turbidity currents

    NARCIS (Netherlands)

    Cartigny, M.

    2012-01-01

    Seafloor and outcrop observations combined with numerical and physical experiments show that turbidity currents are likely 1) to be in a supercritical flow state and 2) to carry high sediment concentrations (being of high-density). The thesis starts with an experimental study of bedforms

  1. Fluorescent Fe K Emission from High Density Accretion Disks

    Science.gov (United States)

    Bautista, Manuel; Mendoza, Claudio; Garcia, Javier; Kallman, Timothy R.; Palmeri, Patrick; Deprince, Jerome; Quinet, Pascal

    2018-06-01

    Iron K-shell lines emitted by gas closely orbiting black holes are observed to be grossly broadened and skewed by Doppler effects and gravitational redshift. Accordingly, models for line profiles are widely used to measure the spin (i.e., the angular momentum) of astrophysical black holes. The accuracy of these spin estimates is called into question because fitting the data requires very high iron abundances, several times the solar value. Meanwhile, no plausible physical explanation has been proffered for why these black hole systems should be so iron rich. The most likely explanation for the super-solar iron abundances is a deficiency in the models, and the leading candidate cause is that current models are inapplicable at densities above 1018 cm-3. We study the effects of high densities on the atomic parameters and on the spectral models for iron ions. At high densities, Debye plasma can affect the effective atomic potential of the ions, leading to observable changes in energy levels and atomic rates with respect to the low density case. High densities also have the effec of lowering energy the atomic continuum and reducing the recombination rate coefficients. On the spectral modeling side, high densities drive level populations toward a Boltzman distribution and very large numbers of excited atomic levels, typically accounted for in theoretical spectral models, may contribute to the K-shell spectrum.

  2. Sputtered thin films for high density tape recording

    NARCIS (Netherlands)

    Nguyen, L.T.

    This thesis describes the investigation of sputtered thin film media for high density tape recording. As discussed in Chapter 1, to meet the tremendous demand of data storage, the density of recording tape has to be increased continuously. For further increasing the bit density the key factors are:

  3. Ultra-stretchable Interconnects for high-density stretchable electronics

    NARCIS (Netherlands)

    Shafqat, S.; Hoefnagels, J.P.M.; Savov, A.; Joshi, S.; Dekker, R.; Geers, M.G.D.

    2017-01-01

    The exciting field of stretchable electronics (SE) promises numerous novel applications, particularly in-body and medical diagnostics devices. However, future advanced SE miniature devices will require high-density, extremely stretchable interconnects with micron-scale footprints, which calls for

  4. Positron camera with high-density avalanche chambers

    International Nuclear Information System (INIS)

    Manfrass, D.; Enghardt, W.; Fromm, W.D.; Wohlfarth, D.; Hennig, K.

    1988-01-01

    The results of an extensive investigation of the properties of high-density avalanche chambers (HIDAC) are presented. This study has been performed in order to optimize the layout of HIDAC detectors, since they are intended to be applied as position sensitive detectors for annihilation radiation in a positron emission tomograph being under construction. (author)

  5. Role of Lipids in Spheroidal High Density Lipoproteins

    NARCIS (Netherlands)

    Vuorela, Timo; Catte, Andrea; Niemela, Perttu S.; Hall, Anette; Hyvonen, Marja T.; Marrink, Siewert-Jan; Karttunen, Mikko; Vattulainen, Ilpo

    2010-01-01

    We study the structure and dynamics of spherical high density lipoprotein (HDL) particles through coarse-grained multi-microsecond molecular dynamics simulations. We simulate both a lipid droplet without the apolipoprotein A-I (apoA-I) and the full HDL particle including two apoA-I molecules

  6. Role of lipids in spheroidal high density lipoproteins

    NARCIS (Netherlands)

    Vuorela, T.A.; Catte, A.; Niemelä, P.S.; Hall, A.; Hyvönen, M.T.; Marrink, S.J.; Karttunen, M.E.J.; Vattulainen, I.

    2010-01-01

    We study the structure and dynamics of spherical high density lipoprotein (HDL) particles through coarse-grained multi-microsecond molecular dynamics simulations. We simulate both a lipid droplet without the apolipoprotein A-I (apoA-I) and the full HDL particle including two apoA-I molecules

  7. Interfacial stick–slip transition in hydroxyapatite filled high density ...

    Indian Academy of Sciences (India)

    Unknown

    flow curves of composites and that of unfilled system remain identical. Filler addition lowers the .... Injection moulding grade high density polyethylene,. HD6070EA, was ... rheometer (Rosand Precision Ltd., UK) using version. 6⋅10 software. .... Bagley E B, Cabbot I M and West D C 1958 J. Appl. Phys. 29. 109. Blyler L L and ...

  8. Spontaneous magnetization in high-density quark matter

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; da Providência, João; Providência, Constanca

    2015-01-01

    It is shown that spontaneous magnetization occurs due to the anomalous magnetic moments of quarks in high-density quark matter under the tensor-type four-point interaction. The spin polarized condensate for each flavor of quark appears at high baryon density, which leads to the spontaneous magnet...

  9. The Influence of Decreased Levels of High Density Lipoprotein ...

    African Journals Online (AJOL)

    Background: Changes in lipoproteins levels in sickle cell disease (SCD) patients are well.known, but the physiological ramifications of the low levels observed have not been entirely resolved. Aim: The aim of this study is to evaluate the impact of decreased levels of high density lipoprotein cholesterol (HDL.c) on ...

  10. Oscillator circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for oscillator circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listing

  11. Measuring circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for measuring circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listings

  12. Identification of a dopamine receptor-mediated opiate reward memory switch in the basolateral amygdala-nucleus accumbens circuit.

    Science.gov (United States)

    Lintas, Alessandra; Chi, Ning; Lauzon, Nicole M; Bishop, Stephanie F; Gholizadeh, Shervin; Sun, Ninglei; Tan, Huibing; Laviolette, Steven R

    2011-08-03

    The basolateral amygdala (BLA), ventral tegmental area (VTA), and nucleus accumbens (NAc) play central roles in the processing of opiate-related associative reward learning and memory. The BLA receives innervation from dopaminergic fibers originating in the VTA, and both dopamine (DA) D1 and D2 receptors are expressed in this region. Using a combination of in vivo single-unit extracellular recording in the NAc combined with behavioral pharmacology studies, we have identified a double dissociation in the functional roles of DA D1 versus D2 receptor transmission in the BLA, which depends on opiate exposure state; thus, in previously opiate-naive rats, blockade of intra-BLA D1, but not D2, receptor transmission blocked the acquisition of associative opiate reward memory, measured in an unbiased conditioned place preference procedure. In direct contrast, in rats made opiate dependent and conditioned in a state of withdrawal, intra-BLA D2, but not D1, receptor blockade blocked opiate reward encoding. This functional switch was dependent on cAMP signaling as comodulation of intra-BLA cAMP levels reversed or replicated the functional effects of intra-BLA D1 or D2 transmission during opiate reward processing. Single-unit in vivo extracellular recordings performed in neurons of the NAc confirmed an opiate-state-dependent role for BLA D1/D2 transmission in NAc neuronal response patterns to morphine. Our results characterize and identify a novel opiate addiction switching mechanism directly in the BLA that can control the processing of opiate reward information as a direct function of opiate exposure state via D1 or D2 receptor signaling substrates.

  13. A New CDS Structure for High Density FPA with Low Power

    Directory of Open Access Journals (Sweden)

    Xiao Wang

    2015-01-01

    Full Text Available Being an essential part of infrared readout integrated circuit, correlated double sampling (CDS circuits play important roles in both depressing reset noise and conditioning integration signals. To adapt applications for focal planes of large format and high density, a new structure of CDS circuit occupying small layout area is proposed, whose power dissipation has been optimized by using MOSFETs in operation of subthreshold region, which leads to 720 nW. Then the noise calculation model is established, based on which the noise analysis has been carried out by the approaches of transfer function and numerical simulations using SIMULINK and Verilog-A. The results are in good agreement, demonstrating the validity of the present noise calculation model. Thermal noise plays a dominant role in the long wave situation while 1/f noise is the majority in the medium wave situation. The total noise of long wave is smaller than medium wave, both of which increase with the integration capacitor and integration time increasing.

  14. High density plasmas formation in Inertial Confinement Fusion and Astrophysics

    International Nuclear Information System (INIS)

    Martinez-Val, J. M.; Minguez, E.; Velarde, P.; Perlado, J. M.; Velarde, G.; Bravo, E.; Eliezer, S.; Florido, R.; Garcia Rubiano, J.; Garcia-Senz, D.; Gil de la Fe, J. M.; Leon, P. T.; Martel, P.; Ogando, F.; Piera, M.; Relano, A.; Rodriguez, R.; Garcia, C.; Gonzalez, E.; Lachaise, M.; Oliva, E.

    2005-01-01

    In inertially confined fusion (ICF), high densities are required to obtain high gains. In Fast Ignition, a high density, low temperature plasma can be obtained during the compression. If the final temperature reached is low enough, the electrons of the plasma can be degenerate. In degenerate plasmas. Bremsstrahlung emission is strongly suppressed an ignition temperature becomes lower than in classical plasmas, which offers a new design window for ICF. The main difficulty of degenerate plasmas in the compression energy needed for high densities. Besides that, the low specific heat of degenerate electrons (as compared to classical values) is also a problem because of the rapid heating of the plasma. Fluid dynamic evolution of supernovae remnants is a very interesting problem in order to predict the thermodynamical conditions achieved in their collision regions. Those conditions have a strong influence in the emission of light and therefore the detection of such events. A laboratory scale system has been designed reproducing the fluid dynamic field in high energy experiments. The evolution of the laboratory system has been calculated with ARWEN code, 2D Radiation CFD that works with Adaptive Mesh Refinement. Results are compared with simulations on the original system obtained with a 3D SPH astrophysical code. New phenomena at the collision plane and scaling of the laboratory magnitudes will be described. Atomic physics for high density plasmas has been studied with participation in experiments to obtain laser produced high density plasmas under NLTE conditions, carried out at LULI. A code, ATOM3R, has been developed which solves rate equations for optically thin plasmas as well as for homogeneous optically thick plasmas making use of escape factors. New improvements in ATOM3R are been done to calculate level populations and opacities for non homogeneous thick plasmas in NLTE, with emphasis in He and H lines for high density plasma diagnosis. Analytical expression

  15. Noise reduction in muon tomography for detecting high density objects

    International Nuclear Information System (INIS)

    Benettoni, M; Checchia, P; Cossutta, L; Furlan, M; Gonella, F; Pegoraro, M; Garola, A Rigoni; Ronchese, P; Vanini, S; Viesti, G; Bettella, G; Bonomi, G; Donzella, A; Subieta, M; Zenoni, A; Calvagno, G; Cortelazzo, G; Zanuttigh, P; Calvini, P; Squarcia, S

    2013-01-01

    The muon tomography technique, based on multiple Coulomb scattering of cosmic ray muons, has been proposed as a tool to detect the presence of high density objects inside closed volumes. In this paper a new and innovative method is presented to handle the density fluctuations (noise) of reconstructed images, a well known problem of this technique. The effectiveness of our method is evaluated using experimental data obtained with a muon tomography prototype located at the Legnaro National Laboratories (LNL) of the Istituto Nazionale di Fisica Nucleare (INFN). The results reported in this paper, obtained with real cosmic ray data, show that with appropriate image filtering and muon momentum classification, the muon tomography technique can detect high density materials, such as lead, albeit surrounded by light or medium density material, in short times. A comparison with algorithms published in literature is also presented

  16. Memory

    OpenAIRE

    Wager, Nadia

    2017-01-01

    This chapter will explore a response to traumatic victimisation which has divided the opinions of psychologists at an exponential rate. We will be examining amnesia for memories of childhood sexual abuse and the potential to recover these memories in adulthood. Whilst this phenomenon is generally accepted in clinical circles, it is seen as highly contentious amongst research psychologists, particularly experimental cognitive psychologists. The chapter will begin with a real case study of a wo...

  17. Operation and control of high density tokamak reactors

    International Nuclear Information System (INIS)

    Attenberger, S.E.; McAlees, D.G.

    1976-01-01

    The incentive for high density operation of a tokamak reactor is discussed. The plasma size required to attain ignition is determined. Ignition is found to be possible in a relatively small system provided other design criteria are met. These criteria are described and the technology developments and operating procedures required by them are outlined. The parameters for such a system and its dynamic behavior during the operating cycle are also discussed

  18. Volume generation of negative ions in high density hydrogen discharges

    International Nuclear Information System (INIS)

    Hiskes, J.R.; Karo, A.M.

    1983-01-01

    A parametric survey is made of a high-density tandem two-chamber hydrogen negative ion system. The optimum extracted negative ion current densities are sensitive to the atom concentration in the discharge and to the system scale length. For scale lengths ranging from 10 cm to 0.1 cm optimum current densities range from of order 1 to 100 mA cm -2 , respectively

  19. Apparatus and method for generating high density pulses of electrons

    International Nuclear Information System (INIS)

    Lee, C.; Oettinger, P.E.

    1981-01-01

    An apparatus and method are described for the production of high density pulses of electrons using a laser energized emitter. Caesium atoms from a low pressure vapour atmosphere are absorbed on and migrate from a metallic target rapidly heated by a laser to a high temperature. Due to this heating time being short compared with the residence time of the caesium atoms adsorbed on the target surface, copious electrons are emitted which form a high current density pulse. (U.K.)

  20. Relativistic many-body theory of high density matter

    International Nuclear Information System (INIS)

    Chin, S.A.

    1977-01-01

    A fully relativistic quantum many-body theory is applied to the study of high-density matter. The latter is identified with the zero-temperature ground state of a system of interacting baryons. In accordance with the observed short-range repulsive and long-range attractive character of the nucleon--nucleon force, baryons are described as interacting with each other via a massive scalar and a massive vector meson exchange. In the Hartree approximation, the theory yields the same result as the mean-field theory, but with additional vacuum fluctuation corrections. The resultant equation of state for neutron matter is used to determine properties of neutron stars. The relativistic exchange energy, its corresponding single-particle excitation spectrum, and its effect on the neutron matter equation of state, are calculated. The correlation energy from summing the set of ring diagrams is derived directly from the energy-momentum tensor, with renormalization carried out by adding counterterms to the original Lagrangian and subtracting purely vacuum expectation values. Terms of order g 4 lng 2 are explicitly given. Effects of scalar-vector mixing are discussed. Collective modes corresponding to macroscopic density fluctuation are investigated. Two basic modes are found, a plasma-like mode and zero sound, with the latter dominant at high density. The stability and damping of these modes are studied. Last, the effect of vacuum polarization in high-density matter is examined

  1. Operation and control of high density tokamak reactors

    International Nuclear Information System (INIS)

    Attenberger, S.E.; McAlees, D.G.

    1976-01-01

    The incentive for high density operation of a tokamak reactor was discussed. It is found that high density permits ignition in a relatively small, moderately elongated plasma with a moderate magnetic field strength. Under these conditions, neutron wall loadings approximately 4 MW/m 2 must be tolerated. The sensitivity analysis with respect to impurity effects shows that impurity control will most likely be necessary to achieve the desired plasma conditions. The charge exchange sputtered impurities are found to have an important effect so that maintaining a low neutral density in the plasma is critical. If it is assumed that neutral beams will be used to heat the plasma to ignition, high energy injection is required (approximately 250 keV) when heating is accompished at full density. A scenario is outlined where the ignition temperature is established at low density and then the fueling rate is increased to attain ignition. This approach may permit beams with energies being developed for use in TFTR to be successfully used to heat a high density device of the type described here to ignition

  2. Evaporation of carbon using electrons of a high density plasma

    International Nuclear Information System (INIS)

    Muhl, S.; Camps, E.; Escobar A, L.; Garcia E, J.L.; Olea, O.

    1999-01-01

    The high density plasmas are used frequently in the preparation of thin films or surface modification, for example to nitridation. In these processes, are used mainly the ions and the neutrals which compose the plasma. However, the electrons present in the plasma are not used, except in the case of chemical reactions induced by collisions, although the electron bombardment usually get hot the work piece. Through the adequate polarization of a conductor material, it is possible to extract electrons from a high density plasma at low pressure, that could be gotten the evaporation of this material. As result of the interaction between the plasma and the electron flux with the vapor produced, this last will be ionized. In this work, it is reported the use of this novelty arrangement to prepare carbon thin films using a high density argon plasma and a high purity graphite bar as material to evaporate. It has been used substrates outside plasma and immersed in the plasma. Also it has been reported the plasma characteristics (temperature and electron density, energy and ions flux), parameters of the deposit process (deposit rate and ion/neutral rate) as well as the properties of the films obtained (IR absorption spectra and UV/Vis, elemental analysis, hardness and refractive index. (Author)

  3. Controlled data storage for non-volatile memory cells embedded in nano magnetic logic

    Science.gov (United States)

    Riente, Fabrizio; Ziemys, Grazvydas; Mattersdorfer, Clemens; Boche, Silke; Turvani, Giovanna; Raberg, Wolfgang; Luber, Sebastian; Breitkreutz-v. Gamm, Stephan

    2017-05-01

    Among the beyond-CMOS technologies, perpendicular Nano Magnetic Logic (pNML) is a promising candidate due to its low power consumption, its non-volatility and its monolithic 3D integrability, which makes it possible to integrate memory and logic into the same device by exploiting the interaction of bi-stable nanomagnets with perpendicular magnetic anisotropy. Logic computation and signal synchronization are achieved by focus ion beam irradiation and by pinning domain walls in magnetic notches. However, in realistic circuits, the information storage and their read-out are crucial issues, often ignored in the exploration of beyond-CMOS devices. In this paper we address these issues by experimentally demonstrating a pNML memory element, whose read and write operations can be controlled by two independent pulsed currents. Our results prove the correct behavior of the proposed structure that enables high density memory embedded in the logic plane of 3D-integrated pNML circuits.

  4. LDRD Final Report - Investigations of the impact of the process integration of deposited magnetic films for magnetic memory technologies on radiation-hardened CMOS devices and circuits - LDRD Project (FY99)

    Energy Technology Data Exchange (ETDEWEB)

    MYERS,DAVID R.; JESSING,JEFFREY R.; SPAHN,OLGA B.; SHANEYFELT,MARTY R.

    2000-01-01

    This project represented a coordinated LLNL-SNL collaboration to investigate the feasibility of developing radiation-hardened magnetic non-volatile memories using giant magnetoresistance (GMR) materials. The intent of this limited-duration study was to investigate whether giant magnetoresistance (GMR) materials similar to those used for magnetic tunnel junctions (MTJs) were process compatible with functioning CMOS circuits. Sandia's work on this project demonstrated that deposition of GMR materials did not affect the operation nor the radiation hardness of Sandia's rad-hard CMOS technology, nor did the integration of GMR materials and exposure to ionizing radiation affect the magnetic properties of the GMR films. Thus, following deposition of GMR films on rad-hard integrated circuits, both the circuits and the films survived ionizing radiation levels consistent with DOE mission requirements. Furthermore, Sandia developed techniques to pattern deposited GMR films without degrading the completed integrated circuits upon which they were deposited. The present feasibility study demonstrated all the necessary processing elements to allow fabrication of the non-volatile memory elements onto an existing CMOS chip, and even allow the use of embedded (on-chip) non-volatile memories for system-on-a-chip applications, even in demanding radiation environments. However, funding agencies DTRA, AIM, and DARPA did not have any funds available to support the required follow-on technology development projects that would have been required to develop functioning prototype circuits, nor were such funds available from LDRD nor from other DOE program funds.

  5. High-density cervical ureaplasma urealyticum colonization in pregnant women

    Directory of Open Access Journals (Sweden)

    Ranđelović Gordana

    2006-01-01

    Full Text Available Background/aim: Ureaplasma urealyticum, a common commensal of the female lower genital tract, has been observed as an important opportunistic pathogen during pregnancy. The aims of this study were to determine the degree of cervical colonization with U. urealyticum in pregnant women with risk pregnancy and in pregnant women with normal term delivery and to evaluate the correlation between high-density cervical U. urealyticum colonization and premature rupture of membranes (PROM as well. Methods. This research was conducted on the samples comprising 130 hospitalized pregnant women with threatening preterm delivery and premature rupture of membranes. The control group consisted of 39 pregnant women with term delivery without PROM. In addition to standard bacteriological examination and performing direct immunofluorescence test to detect Chlamydia trachomatis, cervical swabs were also examined for the presence of U. urealyticum and Mycoplasma hominis by commercially available Mycofast Evolution 2 test (International Microbio, France. Results. The number of findings with isolated high-density U. urealyticum in the target group was 69 (53.08%, while in the control group was 14 (35.90%. Premature rupture of membranes (PROM occurred in 43 (33.08% examinees: 29 were pPROM, and 14 were PROM. The finding of U.urealyticum ≥104 was determined in 25 (58.14% pregnant women with rupture, 17 were pPROM, and 8 were PROM. There was statistically significant difference in the finding of high-density U. urealyticum between the pregnant women with PROM and the control group (χ² = 4.06, p < 0.05. U. urealyticum was predominant bacterial species found in 62.79% of isolates in the PROM cases, while in 32.56% it was isolated alone. Among the 49 pregnant women with preterm delivery, pPROM occurred in 29 (59.18% examinees, and in 70.83% of pregnant women with findings of high-density U. urealyticum pPROM was observed. Conclusion. Cervical colonization with U

  6. Unidirectional threshold switching in Ag/Si-based electrochemical metallization cells for high-density bipolar RRAM applications

    Science.gov (United States)

    Wang, Chao; Song, Bing; Li, Qingjiang; Zeng, Zhongming

    2018-03-01

    We herein present a novel unidirectional threshold selector for cross-point bipolar RRAM array. The proposed Ag/amorphous Si based threshold selector showed excellent threshold characteristics in positive field, such as high selectivity ( 105), steep slope (type RRAM. By integrating a bipolar RRAM device with the selector, experiments showed that the undesired sneak was significantly suppressed, indicating its potentiality for high-density integrated nonvolatile memory applications.

  7. Characterization of the high density plasma etching process of CCTO thin films for the fabrication of very high density capacitors

    International Nuclear Information System (INIS)

    Altamore, C; Tringali, C; Sparta', N; Marco, S Di; Grasso, A; Ravesi, S

    2010-01-01

    In this work the feasibility of CCTO (Calcium Copper Titanate) patterning by etching process is demonstrated and fully characterized in a hard to etch materials etcher. CCTO sintered in powder shows a giant relative dielectric constant (10 5 ) measured at 1 MHz at room temperature. This feature is furthermore coupled with stability from 10 1 Hz to 10 6 Hz in a wide temperature range (100K - 600K). In principle, this property can allow to fabricate very high capacitance density condenser. Due to its perovskite multi-component structure, CCTO can be considered a hard to etch material. For high density capacitor fabrication, CCTO anisotropic etching is requested by using high density plasma. The behavior of etched CCTO was studied in a HRe- (High Density Reflected electron) plasma etcher using Cl 2 /Ar chemistry. The relationship between the etch rate and the Cl 2 /Ar ratio was also studied. The effects of RF MHz, KHz Power and pressure variation, the impact of HBr addiction to the Cl 2 /Ar chemistry on the CCTO etch rate and on its selectivity to Pt and photo resist was investigated.

  8. Characterization of the high density plasma etching process of CCTO thin films for the fabrication of very high density capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Altamore, C; Tringali, C; Sparta' , N; Marco, S Di; Grasso, A; Ravesi, S [STMicroelectronics, Industial and Multi-segment Sector R and D, Catania (Italy)

    2010-02-15

    In this work the feasibility of CCTO (Calcium Copper Titanate) patterning by etching process is demonstrated and fully characterized in a hard to etch materials etcher. CCTO sintered in powder shows a giant relative dielectric constant (10{sup 5}) measured at 1 MHz at room temperature. This feature is furthermore coupled with stability from 10{sup 1} Hz to 10{sup 6} Hz in a wide temperature range (100K - 600K). In principle, this property can allow to fabricate very high capacitance density condenser. Due to its perovskite multi-component structure, CCTO can be considered a hard to etch material. For high density capacitor fabrication, CCTO anisotropic etching is requested by using high density plasma. The behavior of etched CCTO was studied in a HRe- (High Density Reflected electron) plasma etcher using Cl{sub 2}/Ar chemistry. The relationship between the etch rate and the Cl{sub 2}/Ar ratio was also studied. The effects of RF MHz, KHz Power and pressure variation, the impact of HBr addiction to the Cl{sub 2}/Ar chemistry on the CCTO etch rate and on its selectivity to Pt and photo resist was investigated.

  9. A multiply-add engine with monolithically integrated 3D memristor crossbar/CMOS hybrid circuit.

    Science.gov (United States)

    Chakrabarti, B; Lastras-Montaño, M A; Adam, G; Prezioso, M; Hoskins, B; Payvand, M; Madhavan, A; Ghofrani, A; Theogarajan, L; Cheng, K-T; Strukov, D B

    2017-02-14

    Silicon (Si) based complementary metal-oxide semiconductor (CMOS) technology has been the driving force of the information-technology revolution. However, scaling of CMOS technology as per Moore's law has reached a serious bottleneck. Among the emerging technologies memristive devices can be promising for both memory as well as computing applications. Hybrid CMOS/memristor circuits with CMOL (CMOS + "Molecular") architecture have been proposed to combine the extremely high density of the memristive devices with the robustness of CMOS technology, leading to terabit-scale memory and extremely efficient computing paradigm. In this work, we demonstrate a hybrid 3D CMOL circuit with 2 layers of memristive crossbars monolithically integrated on a pre-fabricated CMOS substrate. The integrated crossbars can be fully operated through the underlying CMOS circuitry. The memristive devices in both layers exhibit analog switching behavior with controlled tunability and stable multi-level operation. We perform dot-product operations with the 2D and 3D memristive crossbars to demonstrate the applicability of such 3D CMOL hybrid circuits as a multiply-add engine. To the best of our knowledge this is the first demonstration of a functional 3D CMOL hybrid circuit.

  10. Biomimetic High Density Lipoprotein Nanoparticles For Nucleic Acid Delivery

    Science.gov (United States)

    McMahon, Kaylin M.; Mutharasan, R. Kannan; Tripathy, Sushant; Veliceasa, Dorina; Bobeica, Mariana; Shumaker, Dale K.; Luthi, Andrea J.; Helfand, Brian T.; Ardehali, Hossein; Mirkin, Chad A.; Volpert, Olga; Thaxton, C. Shad

    2014-01-01

    We report a gold nanoparticle-templated high density lipoprotein (HDL AuNP) platform for gene therapy which combines lipid-based nucleic acid transfection strategies with HDL biomimicry. For proof-of-concept, HDL AuNPs are shown to adsorb antisense cholesterylated DNA. The conjugates are internalized by human cells, can be tracked within cells using transmission electron microscopy (TEM), and regulate target gene expression. Overall, the ability to directly image the AuNP core within cells, the chemical tailorability of the HDL AuNP platform, and the potential for cell-specific targeting afforded by HDL biomimicry make this platform appealing for nucleic acid delivery. PMID:21319839

  11. High Density Thermal Energy Storage with Supercritical Fluids

    Science.gov (United States)

    Ganapathi, Gani B.; Wirz, Richard

    2012-01-01

    A novel approach to storing thermal energy with supercritical fluids is being investigated, which if successful, promises to transform the way thermal energy is captured and utilized. The use of supercritical fluids allows cost-affordable high-density storage with a combination of latent heat and sensible heat in the two-phase as well as the supercritical state. This technology will enhance penetration of several thermal power generation applications and high temperature water for commercial use if the overall cost of the technology can be demonstrated to be lower than the current state-of-the-art molten salt using sodium nitrate and potassium nitrate eutectic mixtures.

  12. Optically Addressed Nanostructures for High Density Data Storage

    Science.gov (United States)

    2005-10-14

    beam to sub-wavelength resolutions. X. Refereed Journal Publications I. M. D. Stenner , D. J. Gauthier, and M. A. Neifeld, "The speed of information in a...profiles for high-density optical data storage," Optics Communications, Vol.253, pp.56-69, 2005. 5. M. D. Stenner , D. J. Gauthier, and M. A. Neifeld, "Fast...causal information transmission in a medium with a slow group velocity," Physical Review Letters, Vol.94, February 2005. 6. M. D. Stenner , M. A

  13. Viscosity and attenuation of sound wave in high density deuterium

    International Nuclear Information System (INIS)

    Inoue, Kazuko; Ariyasu, Tomio

    1985-01-01

    The penetration of low frequency sound wave into the fuel deuterium is discussed as for laser fusion. The sound velocity and the attenuation constant due to viscosity are calculated for high density (n = 10 24 -- 10 27 cm -3 , T = 10 -1 -- 10 4 eV) deuterium. The shear viscosity of free electron gas and the bulk viscosity due to ion-ion interaction mainly contribute to the attenuation of sound wave. The sound wave of the frequency below 10 10 Hz can easily penetrate through the compressed fuel deuterium of diameter 1 -- 10 3 μm. (author)

  14. Low-frequency oscillations at high density in JFT-2

    International Nuclear Information System (INIS)

    Maeno, Masaki; Katagiri, Masaki; Suzuki, Norio; Fujisawa, Noboru

    1977-12-01

    Low-frequency oscillations in a plasma were measured with magnetic probes and Si surface-barrier detectors, and behaviour of the high density plasmas was studied. The plasma current profile in the phase of decreasing density after the interruption of gas input is more peaked than during gas input. The introduction of hydrogen during a discharge results in a reduction of the impurities flux. The increase of density by fast gas input is limited with a negative voltage spike. Immediately before a negative voltage spike, oscillations of m=1,2 grow, leading to the spike. (auth.)

  15. Possible new form of matter at high density

    International Nuclear Information System (INIS)

    Lee, T.D.

    1974-01-01

    As a preliminary to discussion of the possibility of new forms of matter at high density, questions relating to the vacuum and vacuum excitation are considered. A quasi-classical approach to the development of abnormal nuclear states is undertaken using a Fermi gas of nucleons of uniform density. Discontinuous transitions are considered in the sigma model (tree approximation) followed by brief consideration of higher order loop diagrams. Production and detection of abnormal nuclear states are discussed in the context of high energy heavy ion collisions. Remarks are made on motivation for such research. 8 figures

  16. Characterization of composite high density polyethylene and layered zirconium phosphate

    International Nuclear Information System (INIS)

    Lino, Adan S.; Silva, Daniela F.; Mendes, Luis C.

    2011-01-01

    Zirconium phosphate (ZrP) (2 w%), synthesized by direct precipitation method, was used in the preparation of composite with high density polyethylene (HDPE), through extrusion processing in the molten state. Wide angle x-ray diffraction (WAXD), stress-strain mechanical analysis and scanning electron microscopy (SEM) techniques were used for ZrP, neat polymer and composite mechanical and morphologic characterization. Although there was a slight increase in the Young modulus, WAXD and SEM analysis showed that the intercalation of the HDPE matrix in the filler galleries did not occur, probably due to the insufficient lamellae spacing to intercalate the polymer chains. Then, a microcomposite was achieved. (author)

  17. Structure of high-density amorphous ice under pressure

    International Nuclear Information System (INIS)

    Klotz, S.; Hamel, G.; Loveday, J.S.; Nelmes, R.J.; Guthrie, M.; Soper, A.K.

    2002-01-01

    We report in situ neutron diffraction studies of high-density amorphous ice (HDA) at 100 K at pressures up to 2.2 GPa. We find that the compression is achieved by a strong contraction (∼20%) of the second neighbor coordination shell, so that at 2.2 GPa it closely approaches the first coordination shell, which itself remains intact in both structure and size. The hydrogen bond orientations suggest an absence of hydrogen bonding between first and second shells and that HDA has increasingly interpenetrating hydrogen bond networks under pressure

  18. Behavior of high-density spent-fuel storage racks

    International Nuclear Information System (INIS)

    Bailey, W.J.

    1986-08-01

    Included in this report is a summary of information on neutron-absorbing materials such as B 4 C in an aluminum matrix or organic binder material, stainless steel-boron and aluminum-boron alloys, and stainless steetl-clad cadmium that are used in high-density spent fuel storage racks. A list of the types of neutron-absorbing materials being used in spent fuel storage racks at domestic commercial plants is provided. Recent cases at several domestic plants where swelling of rack side plates (where the B 4 C in an aluminum matrix and B 4 C in an organic binder material were located) occurred are reviewed

  19. Memories.

    Science.gov (United States)

    Brand, Judith, Ed.

    1998-01-01

    This theme issue of the journal "Exploring" covers the topic of "memories" and describes an exhibition at San Francisco's Exploratorium that ran from May 22, 1998 through January 1999 and that contained over 40 hands-on exhibits, demonstrations, artworks, images, sounds, smells, and tastes that demonstrated and depicted the biological,…

  20. High-density carrier-accumulated and electrically stable oxide thin-film transistors from ion-gel gate dielectric.

    Science.gov (United States)

    Fujii, Mami N; Ishikawa, Yasuaki; Miwa, Kazumoto; Okada, Hiromi; Uraoka, Yukiharu; Ono, Shimpei

    2015-12-18

    The use of indium-gallium-zinc oxide (IGZO) has paved the way for high-resolution uniform displays or integrated circuits with transparent and flexible devices. However, achieving highly reliable devices that use IGZO for low-temperature processes remains a technological challenge. We propose the use of IGZO thin-film transistors (TFTs) with an ionic-liquid gate dielectric in order to achieve high-density carrier-accumulated IGZO TFTs with high reliability, and we discuss a distinctive mechanism for the degradation of this organic-inorganic hybrid device under long-term electrical stress. Our results demonstrated that an ionic liquid or gel gate dielectric provides highly reliable and low-voltage operation with IGZO TFTs. Furthermore, high-density carrier accumulation helps improve the TFT characteristics and reliability, and it is highly relevant to the electronic phase control of oxide materials and the degradation mechanism for organic-inorganic hybrid devices.

  1. Development of liquid film thickness measurement technique by high-density multipoint electrodes method

    International Nuclear Information System (INIS)

    Arai, Takahiro; Furuya, Masahiro; Kanai, Taizo

    2010-01-01

    High-density multipoint electrode method was developed to measure a liquid film thickness transient on a curved surface. The devised method allows us to measure spatial distribution of liquid film with its conductance between electrodes. The sensor was designed and fabricated as a multilayer print circuit board, where electrode pairs were distributed in reticular pattern with narrow interval. In order to measure a lot of electrode pairs at a high sampling rate, signal-processing method used by the wire mesh sensor measurement system was applied. An electrochemical impedance spectrometry concludes that the sampling rate of 1000 slices/s is feasible without signal distortion by electric double layer. The method was validated with two experimental campaigns: (1) a droplet impingement on a flat film and (2) a jet impingement on a rod-shape sensor surface. In the former experiment, a water droplet having 4 mm in diameter impinged onto the 1 mm thick film layer. A visual observation study with high-speed video camera shows after the liquid impingement, the water layer thinning process was clearly demonstrated with the sensor. For the latter experiment, the flexible circuit board was bended to form a cylindrical shape to measure water film on a simulated fuel rod in bundle geometry. A water jet having 3 mm in diameter impinged onto the rod-shape sensor surface. The process of wetting area enlargement on the rod surface was demonstrated in the same manner that the video-frames showed. (author)

  2. Mixing of high density solution in vertical upward flow

    International Nuclear Information System (INIS)

    Kumamaru, Hiroshige; Hosogi, Nobuyoshi; Komada, Toshiaki; Fujiwara, Yoshiki

    1999-01-01

    Experimental and analytical studies have been performed in order to provide fundamental data and a numerical calculation model on the mixing of boric acid solution, injected from the standby liquid control system (SLCS), under a low natural circulation flow during an ATWS in a BWR. First, fundamental experiments on the mixing of high-density solution in vertically-upward water flow have been performed by using a small apparatus. Mixing patterns observed in the experiments have been classified to two groups, i.e. complete mixing (entrainment) and incomplete mixing (entrainment). In the complete mixing, the injected high-density solution is mixed (entrained) completely into the vertically-upward water flow. From the experiments, the minimum water flow rates in which the complete mixing (entrainment) is achieved have been obtained for various solution densities and solution injection rates. Secondly, two-dimensional numerical calculations have been performed. A continuity equation for total fluid, momentum equations in two directions and a continuity equation for solute are solved by using the finite difference method for discretization method and by following the MAC method for solution procedure. The calculations have predicted nearly the minimum water flow rate in which the complete mixing is achieved, while the calculations have been performed only for one combination of the solution density and solution injection rate until now. (author)

  3. Manufacture of sintered bricks of high density from beryllium oxide

    International Nuclear Information System (INIS)

    Pointud, R.; Rispal, Ch.; Le Garec, M.

    1959-01-01

    Beryllium oxide bricks of nuclear purity 100 x 100 x 50 and 100 x 100 x 100 mm of very high density (between 2.85 and 3.00) are manufactured by sintering under pressure in graphite moulds at temperatures between 1,750 and 1,850 deg. C, and under a pressure of 150 kg/cm 2 . The physico-chemical state of the saw material is of considerable importance with regard to the success of the sintering operation. In addition, a study of the sintering of a BeO mixture with 3 to 5 per cent of boron introduced in the form of boric acid, boron carbide or elementary boron shows that high densities can only be obtained by sintering under pressure. For technical reasons of manufacture, only the mixture based on boron carbide is used. The sintering is carried out in graphite moulds at 1500 deg. C under 150 kg/cm 2 pressure, and bricks can be obtained with density between 2,85 and 2,90. Laboratory studies and the industrial manufacture of various sinters are described in detail. (author) [fr

  4. Development of technology of high density LEU dispersion fuel fabrication

    International Nuclear Information System (INIS)

    Wiencek, T.; Totev, T.

    2007-01-01

    Advanced Materials Fabrication Facilities at Argonne National Laboratory have been involved in development of LEU dispersion fuel for research and test reactors from the beginning of RERTR program. This paper presents development of technology of high density LEU dispersion fuel fabrication for full size plate type fuel elements. A brief description of Advanced Materials Fabrication Facilities where development of the technology was carried out is given. A flow diagram of the manufacturing process is presented. U-Mo powder was manufactured by the rotating electrode process. The atomization produced a U-Mo alloy powder with a relatively uniform size distribution and a nearly spherical shape. Test plates were fabricated using tungsten and depleted U-7 wt.% Mo alloy, 4043 Al and Al-2 wt% Si matrices with Al 6061 aluminum alloy for the cladding. During the development of the technology of manufacturing of full size high density LEU dispersion fuel plates special attention was paid to meet the required homogeneity, bonding, dimensions, fuel out of zone and other mechanical characteristics of the plates.

  5. SERODS: a new medium for high-density optical data storage

    Science.gov (United States)

    Vo-Dinh, Tuan; Stokes, David L.

    1998-10-01

    A new optical dada storage technology based on the surface- enhanced Raman scattering (SERS) effect has been developed for high-density optical memory and three-dimensional data storage. With the surface-enhanced Raman optical data storage (SERODS) technology, the molecular interactions between the optical layer molecules and the nanostructured metal substrate are modified by the writing laser, changing their SERS properties to encode information as bits. Since the SERS properties are extremely sensitive to molecular nano- environments, very small 'spectrochemical holes' approaching the diffraction limit can be produced for the writing process. The SERODS device uses a reading laser to induce the SERS emission of molecules on the disk and a photometric detector tuned to the frequency of the RAMAN spectrum to retrieve the stored information. The results illustrate that SERODS is capable of three-dimensional data storage and has the potential to achieve higher storage density than currently available optical data storage systems.

  6. A distributed current stimulator ASIC for high density neural stimulation.

    Science.gov (United States)

    Jeong Hoan Park; Chaebin Kim; Seung-Hee Ahn; Tae Mok Gwon; Joonsoo Jeong; Sang Beom Jun; Sung June Kim

    2016-08-01

    This paper presents a novel distributed neural stimulator scheme. Instead of a single stimulator ASIC in the package, multiple ASICs are embedded at each electrode site for stimulation with a high density electrode array. This distributed architecture enables the simplification of wiring between electrodes and stimulator ASIC that otherwise could become too complex as the number of electrode increases. The individual ASIC chip is designed to have a shared data bus that independently controls multiple stimulating channels. Therefore, the number of metal lines is determined by the distributed ASICs, not by the channel number. The function of current steering is also implemented within each ASIC in order to increase the effective number of channels via pseudo channel stimulation. Therefore, the chip area can be used more efficiently. The designed chip was fabricated with area of 0.3 mm2 using 0.18 μm BCDMOS process, and the bench-top test was also conducted to validate chip performance.

  7. Automatic Calibration of High Density Electric Muscle Stimulation

    DEFF Research Database (Denmark)

    Knibbe, Jarrod; Strohmeier, Paul; Boring, Sebastian

    2017-01-01

    . (2) EMS requires time consuming, expert calibration -- confining these interaction techniques to the lab. EMS arrays have been shown to increase stimulation resolution, but as calibration complexity increases exponentially as more electrodes are used, we require heuristics or automated procedures......Electric muscle stimulation (EMS) can enable mobile force feedback, support pedestrian navigation, or confer object affordances. To date, however, EMS is limited by two interlinked problems. (1) EMS is low resolution -- achieving only coarse movements and constraining opportunities for exploration...... for successful calibration. We explore the feasibility of using electromyography (EMG) to auto-calibrate high density EMS arrays. We determine regions of muscle activity during human-performed gestures, to inform stimulation patterns for EMS-performed gestures. We report on a study which shows that auto...

  8. A high-density lipoprotein-mediated drug delivery system.

    Science.gov (United States)

    Mo, Zhong-Cheng; Ren, Kun; Liu, Xing; Tang, Zhen-Li; Yi, Guang-Hui

    2016-11-15

    High-density lipoprotein (HDL) is a comparatively dense and small lipoprotein that can carry lipids as a multifunctional aggregate in plasma. Several studies have shown that increasing the levels or improving the functionality of HDL is a promising target for treating a wide variety of diseases. Among lipoproteins, HDL particles possess unique physicochemical properties, including naturally synthesized physiological components, amphipathic apolipoproteins, lipid-loading and hydrophobic agent-incorporating characteristics, specific protein-protein interactions, heterogeneity, nanoparticles, and smaller size. Recently, the feasibility and superiority of using HDL particles as drug delivery vehicles have been of great interest. In this review, we summarize the structure, constituents, biogenesis, remodeling, and reconstitution of HDL drug delivery systems, focusing on their delivery capability, characteristics, applications, manufacturing, and drug-loading and drug-targeting characteristics. Finally, the future prospects are presented regarding the clinical application and challenges of using HDL as a pharmacodelivery carrier. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. High-Density Lipoproteins and the Immune System

    Directory of Open Access Journals (Sweden)

    Hidesuke Kaji

    2013-01-01

    Full Text Available High-density lipoprotein (HDL plays a major role in vasodilation and in the reduction of low-density lipoprotein (LDL oxidation, inflammation, apoptosis, thrombosis, and infection; however, HDL is now less functional in these roles under certain conditions. This paper focuses on HDL, its anti-inflammation behavior, and the mechanisms by which HDL interacts with components of the innate and adaptive immune systems. Genome-wide association studies (GWAS and proteomic studies have elucidated important molecules involved in the interaction between HDL and the immune system. An understanding of these mechanisms is expected to be useful for the prevention and treatment of chronic inflammation due to metabolic syndrome, atherosclerosis, or various autoimmune diseases.

  10. Reaction of unirradiated high-density fuel with aluminum

    International Nuclear Information System (INIS)

    Wiencek, T.C.; Meyer, M.K.; Prokofiev, I.G.; Keiser, D.D.

    1997-01-01

    Excellent dispersion fuel performance requires that fuel particles remain stable and do not react significantly with the surrounding aluminum matrix. A series of high-density fuels, which contain uranium densities >12 g/cm 3 , have been fabricated into plates. As part of standard processing, all of these fuels were subjected to a blister anneal of 1 h at 485 deg. C. Changes in plate thickness were measured and evaluated. From these results, suppositions about the probable irradiation properties of these fuels have been proposed. In addition, two fuels, U-10 wt% Mo and U 2 Mo, were subjected to various heat treatments and were found to be very stable in an aluminum matrix. On the basis of the experimental data, hypotheses of the irradiation behavior of these fuels are presented. (author)

  11. High-current discharge channel contraction in high density gas

    International Nuclear Information System (INIS)

    Rutberg, Ph. G.; Bogomaz, A. A.; Pinchuk, M. E.; Budin, A. V.; Leks, A. G.; Pozubenkov, A. A.

    2011-01-01

    Research results for discharges at current amplitudes of 0.5-1.6 MA and current rise rate of ∼10 10 A/s are presented. The discharge is performed in the hydrogen environment at the initial pressure of 5-35 MPa. Initiation is implemented by a wire explosion. The time length of the first half-period of the discharge current is 70-150 μs. Under such conditions, discharge channel contraction is observed; the contraction is followed by soft x-ray radiation. The phenomena are discussed, which are determined by high density of the gas surrounding the discharge channel. These phenomena are increase of the current critical value, where the channel contraction begins and growth of temperature in the axis region of the channel, where the initial density of the gas increases.

  12. Diquark Bose Condensates in High Density Matter and Instantons

    International Nuclear Information System (INIS)

    Rapp, R.; Shuryak, E.; Schaefer, T.; Velkovsky, M.

    1998-01-01

    Instantons lead to strong correlations between up and down quarks with spin zero and antisymmetric color wave functions. In cold and dense matter, n b >n c ≅1 fm -3 and T c ∼50 thinspthinspMeV, these pairs Bose condense, replacing the usual left-angle bar qq right-angle condensate and restoring chiral symmetry. At high density, the ground state is a color superconductor in which diquarks play the role of Cooper pairs. An interesting toy model is provided by QCD with two colors: it has a particle-antiparticle symmetry which relates left-angle bar qq right-angle and left-angle qq right-angle condensates. copyright 1998 The American Physical Society

  13. High-Density Near-Field Optical Disc Recording

    Science.gov (United States)

    Shinoda, Masataka; Saito, Kimihiro; Ishimoto, Tsutomu; Kondo, Takao; Nakaoki, Ariyoshi; Ide, Naoki; Furuki, Motohiro; Takeda, Minoru; Akiyama, Yuji; Shimouma, Takashi; Yamamoto, Masanobu

    2005-05-01

    We developed a high-density near-field optical recording disc system using a solid immersion lens. The near-field optical pick-up consists of a solid immersion lens with a numerical aperture of 1.84. The laser wavelength for recording is 405 nm. In order to realize the near-field optical recording disc, we used a phase-change recording media and a molded polycarbonate substrate. A clear eye pattern of 112 GB capacity with 160 nm track pitch and 50 nm bit length was observed. The equivalent areal density is 80.6 Gbit/in2. The bottom bit error rate of 3 tracks-write was 4.5× 10-5. The readout power margin and the recording power margin were ± 30.4% and ± 11.2%, respectively.

  14. EVALUATION OF SOME PLUM CULTIVARS IN A HIGH DENSITY SYSTEM

    Directory of Open Access Journals (Sweden)

    Madalina Butac

    2014-12-01

    Full Text Available Three plum cultivars bred in Romania (‘Carpatin’, ‘Centenar’ and ‘Tita’ were tested together with several standards (‘Cacanska Rodna’ and ‘Stanley’ in a high density experimental orchard established at Pitesti - Maracineni in the spring of 2009, with spacing 4 x 2.25 m. Trees were trained as spindles, grafted on ‘Saint Julian’ rootstock. In the orchard the following characteristics were evaluated: tree vigour based upon measuring of trunk-diameter, yields in kg/tree, time of fruit ripening and basic parameters of fruit quality. All Romanian varieties were characterized by earliness and large fruit, but production was relatively small. Instead, foreign varieties were characterized by high productivity in the 4th year after planting.

  15. High density thermite mixture for shaped charge ordnance disposal

    Directory of Open Access Journals (Sweden)

    Tamer Elshenawy

    2017-10-01

    Full Text Available The effect of thermite mixture based on aluminum and ferric oxides for ammunition neutralization has been studied and tested. Thermochemical calculations have been carried out for different percentage of Al using Chemical Equilibrium Code to expect the highest performance thermite mixture used for shaped charge ordnance disposal. Densities and enthalpy of different formulations have been calculated and demonstrated. The optimized thermite formulation has been prepared experimentally using cold iso-static pressing technique, which exhibited relatively high density and high burning rate thermite mixture. The produced green product compacted powder mixture was tested against small caliber shaped charge bomblet for neutralization. Theoretical and experimental results showed that the prepared thermite mixture containing 33% of aluminum as a fuel with ferric oxide can be successfully used for shaped charge ordnance disposal.

  16. The stability of the High-Density Z-Pinch

    International Nuclear Information System (INIS)

    Glasser, A.H.; Nebel, R.A.

    1989-01-01

    Fiber-initiated High Density Z-Pinches at Los Alamos, NRL, and Karlsruhe have shown anomalously good stability. Kink modes are never seen, and sausage modes are at least delayed until late in the discharge. The success of these devices in reaching fusion conditions may depend on maintaining and understanding this anomalous stability. We have developed two numerical methods to study the stability in the regime where fluid theory is valid. While our methods are applicable to all modes, we will describe them only for the m = 0 sausage mode. The appearance of sausage modes late in the discharge and the total absence of kink modes suggest that an understanding of sausage modes is more urgent, and it is also simpler. 14 refs., 8 figs

  17. The stability of the high-density z-pinch

    International Nuclear Information System (INIS)

    Glasser, A.H.; Nebel, R.A.

    1989-01-01

    Fiber-initiated High Density Z-Pinches at Los Alamos, NRL, and Karlsruhe have shown anomalously good stability. Kink modes are never seen, and sausage modes are at least delayed until late in the discharge. The success of these devices in reaching fusion conditions may depend on maintaining and understanding this anomalous stability. We have developed two numerical methods to study the stability in the regime where fluid theory is valid. While our methods are applicable to all modes, we will describe them only for the m=0 sausage mode. The appearance of sausage modes late in the discharge and the total absence of kink modes suggest that an understanding of sausage modes is more urgent, and it is also simpler

  18. Corrosion of high-density sintered tungsten alloys. Part 2

    International Nuclear Information System (INIS)

    Batten, J.J.; Moore, B.T.

    1988-12-01

    The behaviour of four high-density sintered tungsten alloys has been evluated and compared with that of pure tungsten. Rates of corrosion during the cyclic humidity and the salt mist tests were ascertained from weight loss measurements. Insight into the corrosion mechanism was gained from the nature of the corrosion products and an examination of the corroded surfaces. In the tests, the alloy 95% W, 2.5% Ni, 1.5% Fe was the most corrosion resistant. The data showed that copper as an alloying element accelerates corrosion of tungsten alloys. Both attack on the tungsten particles and the binder phase were observed together with tungsten grain loss. 6 refs., 3 tabs.,

  19. High density high-TC ceramic superconductors by hot pressing

    International Nuclear Information System (INIS)

    Mak, S.; Chaklader, A.C.D.

    1989-01-01

    High density and high T C superconductor specimens, YBa 2 Cu 3 O x , have been produced by hot-pressing. The factors studied are the effect of hot pressing on the density, the oxygen stoichiometry, the crystal structure, and the critical temperature. Hot pressing followed by heat treatment increased the density of the specimen to 93%. The hot pressing itself did not significantly affect the oxygen content in the specimen, and although the crystal structure appeared to be orthorhombic, the specimens were not superconducting above liquid nitrogen temperature. The superconductivity was restored after head treatment in oxygen. The highest critical temperature (T C ) of the hot pressed pellets was 82K, which was slightly lower than the T C that could be obtained with the cold pressed/sintered pellets. (6 refs., 5 figs., tab.)

  20. Evaluation of the radiation resistance of high-density polyethylene

    International Nuclear Information System (INIS)

    Dougherty, D.R.; Adams, J.W.; Barletta, R.R.

    1984-03-01

    Mechanical tests following gamma irradiation and creep tests during irradiation have been conducted on high-density polyethylene (HDPE) to provide data to help assess the adequacy of this material for use in high integrity containers (HICs). Two types of HDPE, a highly cross-linked rotationally molded material and a non-cross-linked blow molded material, were used in these tests. Gamma-ray irradiations were performed at several dose rates in environments of air, Barnwell and Hanford backfill soils, and ion-exchange resins. The results of tensile and bend tests on these materials following irradiation are presented along with results on creep during irradiation. 8 references, 9 figures, 2 tables

  1. The Pulsed High Density Experiment (PHDX) Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Slough, John P. [Univ. of Washington, Seattle, WA (United States); Andreason, Samuel [Univ. of Washington, Seattle, WA (United States)

    2017-04-27

    The purpose of this paper is to present the conclusions that can be drawn from the Field Reversed Configuration (FRC) formation experiments conducted on the Pulsed High Density experiment (PHD) at the University of Washington. The experiment is ongoing. The experimental goal for this first stage of PHD was to generate a stable, high flux (>10 mWb), high energy (>10 KJ) target FRC. Such results would be adequate as a starting point for several later experiments. This work focuses on experimental implementation and the results of the first four month run. Difficulties were encountered due to the initial on-axis plasma ionization source. Flux trapping with this ionization source acting alone was insufficient to accomplish experimental objectives. Additional ionization methods were utilized to overcome this difficulty. A more ideal plasma source layout is suggested and will be explored during a forthcoming work.

  2. The alterations in high density polyethylene properties with gamma irradiation

    Science.gov (United States)

    Zaki, M. F.; Elshaer, Y. H.; Taha, Doaa. H.

    2017-10-01

    In the present investigation, high density polyethylene (HDPE) polymer has been used to study the alterations in its properties under gamma-irradiation. Physico-chemical properties have been investigated with different spectroscopy techniques, Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), biocompatibility properties, as well as, mechanical properties change. The FT-IR analysis shows the formation of new band at 1716 cm-1 that is attributed to the oxidation of irradiated polymer chains, which is due to the formation of carbonyl groups (C˭O). XRD patterns show that a decrease in the crystallite size and increase in the Full Width at Half Maximum (FWHM). This means that the crystallinity of irradiated samples is decreased with increase in gamma dose. The contact angle measurements show an increase in the surface free energy as the gamma irradiation increases. The measurements of mechanical properties of irradiated HDPE samples were discussed.

  3. Relaxation Time of High-Density Amorphous Ice

    Science.gov (United States)

    Handle, Philip H.; Seidl, Markus; Loerting, Thomas

    2012-06-01

    Amorphous water plays a fundamental role in astrophysics, cryoelectron microscopy, hydration of matter, and our understanding of anomalous liquid water properties. Yet, the characteristics of the relaxation processes taking place in high-density amorphous ice (HDA) are unknown. We here reveal that the relaxation processes in HDA at 110-135 K at 0.1-0.2 GPa are of collective and global nature, resembling the alpha relaxation in glassy material. Measured relaxation times suggest liquid-like relaxation characteristics in the vicinity of the crystallization temperature at 145 K. By carefully relaxing pressurized HDA for several hours at 135 K, we produce a state that is closer to the ideal glass state than all HDA states discussed so far in literature.

  4. High-density amorphous ice: A path-integral simulation

    Science.gov (United States)

    Herrero, Carlos P.; Ramírez, Rafael

    2012-09-01

    Structural and thermodynamic properties of high-density amorphous (HDA) ice have been studied by path-integral molecular dynamics simulations in the isothermal-isobaric ensemble. Interatomic interactions were modeled by using the effective q-TIP4P/F potential for flexible water. Quantum nuclear motion is found to affect several observable properties of the amorphous solid. At low temperature (T = 50 K) the molar volume of HDA ice is found to increase by 6%, and the intramolecular O-H distance rises by 1.4% due to quantum motion. Peaks in the radial distribution function of HDA ice are broadened with respect to their classical expectancy. The bulk modulus, B, is found to rise linearly with the pressure, with a slope ∂B/∂P = 7.1. Our results are compared with those derived earlier from classical and path-integral simulations of HDA ice. We discuss similarities and discrepancies with those earlier simulations.

  5. Characterization of High Density Concrete by Ultrasonic Goniometer

    International Nuclear Information System (INIS)

    Suhairy Sani; Mohamad Pauzi Ismail; Noor Azreen Masenwat; Nasharuddin Isa; Mohamad Haniza Mahmud

    2014-01-01

    This paper described the results of ultrasonic goniometer measurements on concrete containing hematite. Local hematite stones were used as aggregates to produce high density concrete for application in X-and gamma shielding. Concrete cube samples (150 mm x 150 mm x 150 mm) containing hematite as coarse aggregates were prepared by changing mix ratio, water to cement ratio (w/ c) and types of fine aggregate. All samples were cured in water for 7 days. After 28 days of casting, the concrete cubes were then cut into small size of about 10 mm x 20 mm x 30 mm so that it can be fitted into goniometer specimen holder. From this measurement, longitudinal, shear and surface Rayleigh waves in the concrete can be determined. The measurement results are explained and discussed. (author)

  6. Microelectromechanical high-density energy storage/rapid release system

    Science.gov (United States)

    Rodgers, M. Steven; Allen, James J.; Meeks, Kent D.; Jensen, Brian D.; Miller, Samuel L.

    1999-08-01

    One highly desirable characteristic of electrostatically driven microelectromechanical systems (MEMS) is that they consume very little power. The corresponding drawback is that the force they produce may be inadequate for many applications. It has previously been demonstrated that gear reduction units or microtransmissions can substantially increase the torque generated by microengines. Operating speed, however, is also reduced by the transmission gear ratio. Some applications require both high speed and high force. If this output is only required for a limited period of time, then energy could be stored in a mechanical system and rapidly released upon demand. We have designed, fabricated, and demonstrated a high-density energy storage/rapid release system that accomplishes this task. Built using a 5-level surface micromachining technology, the assembly closely resembles a medieval crossbow. Energy releases on the order of tens of nanojoules have already been demonstrated, and significantly higher energy systems are under development.

  7. Preparations of high density (Th,U)O2 pellets

    International Nuclear Information System (INIS)

    Akabori, Mitsuo; Ikawa, Katsuichi

    1986-07-01

    Preparations of high density and homogeneous (Th,U)O 2 pellets by a powder metallurgy method were examined. (Th,U)O 2 powders were prepared by calcining coprecipitates of ammonium uranate and thorium hydroxide derived from nitrates and mixed sols, and by calcining mixed oxalates precipitated from nitrates. (Th,U)O 2 pellets were characterized with respect to sinterability, lattice parameter, microstructure, homogeneity and stoichiometry. Sintering atmospheres had a significant effect upon all the properties of the derived pellets. The sinterability of (Th,U)O 2 was most favourable in oxidizing and reducing atmospheres for ThO 2 -rich and UO 2 -rich compositions, respectively, and can be enhanced by presence of water vapour in sintering atmospheres. In addition, highly homogeneous (Th,U)O 2 pellets with 99 % in theoretical density were derived from the sol powders. (author)

  8. Neutron shielding properties of a borated high-density glass

    Directory of Open Access Journals (Sweden)

    Saeed Aly Abdallah

    2017-01-01

    Full Text Available The neutron shielding properties of a borated high density glass system was characterized experimentally. The total removal macroscopic cross-section of fast neutrons, slow neutrons as well as the linear attenuation coefficient of total gamma rays, primary in addition to secondary, were measured experimentally under good geometric condition to characterize the attenuation properties of (75-x B2O3-1Li2O-5MgO-5ZnO-14Na2O-xBaO glassy system. Slabs of different thicknesses from the investigated glass system were exposed to a collimated beam of neutrons emitted from 252Cf and 241Am-Be neutron sources in order to measure the attenuation properties of fast and slow neutrons as well as total gamma rays. Results confirmed that barium borate glass was suitable for practical use in the field of radiation shielding.

  9. Biominetic High Density Lipoproteins for the Delivery of Therapeutic Oligonucleotides

    Science.gov (United States)

    Tripathy, Sushant

    Advances in nanotechnology have brought about novel inorganic and hybrid nanoparticles with unique physico-chemical properties that make them suitable for a broad range of applications---from nano-circuitry to drug delivery. A significant part of those advancements have led to ground-breaking discoveries that have changed the approaches to formulation of therapeutics against diseases, such as cancer. Now-a-days the focus does not lie solely on finding a candidate small-molecule therapeutic with minimal adverse effects, but researchers are looking up to nanoparticles to improve biodistribution and biocompatibility profile of clinically proven therapeutics. The plethora of conjugation chemistries offered by currently extant inorganic nanoparticles have, in recent years, led to great leaps in the field of biomimicry---a modality that promises high biocompatibility. Further, in the pursuit of highly specific therapeutic molecules, researchers have turned to silencing oligonucleotides and some have already brought together the strengths of nanoparticles and silencing oligonucleotides in search of an efficacious therapy for cancer with minimal adverse effects. This dissertation work focuses on such a biomimetic platform---a gold nanoparticle based high density lipoprotein biomimetic (HDL NP), for the delivery of therapeutic oligonucleotides. The first chapter of this body of work introduces the molecular target of the silencing oligonucleotides---VEGFR2, and its role in the progression of solid tumor cancers. The background information also covers important aspects of natural high density lipoproteins (HDL), especially their innate capacity to bind and deliver exogenous and endogenous silencing oligonucleotides to tissues that express their high affinity receptor SRB1. We subsequently describe the synthesis of the biomimetic HDL NP and its oligonucleotide conjugates, and establish their biocompatibility. Further on, experimental data demonstrate the efficacy of silencing

  10. Rethinking reverse cholesterol transport and dysfunctional high-density lipoproteins.

    Science.gov (United States)

    Gillard, Baiba K; Rosales, Corina; Xu, Bingqing; Gotto, Antonio M; Pownall, Henry J

    2018-04-12

    Human plasma high-density lipoprotein cholesterol concentrations are a negative risk factor for atherosclerosis-linked cardiovascular disease. Pharmacological attempts to reduce atherosclerotic cardiovascular disease by increasing plasma high-density lipoprotein cholesterol have been disappointing so that recent research has shifted from HDL quantity to HDL quality, that is, functional vs dysfunctional HDL. HDL has varying degrees of dysfunction reflected in impaired reverse cholesterol transport (RCT). In the context of atheroprotection, RCT occurs by 2 mechanisms: one is the well-known trans-hepatic pathway comprising macrophage free cholesterol (FC) efflux, which produces early forms of FC-rich nascent HDL (nHDL). Lecithin:cholesterol acyltransferase converts HDL-FC to HDL-cholesteryl ester while converting nHDL from a disc to a mature spherical HDL, which transfers its cholesteryl ester to the hepatic HDL receptor, scavenger receptor B1 for uptake, conversion to bile salts, or transfer to the intestine for excretion. Although widely cited, current evidence suggests that this is a minor pathway and that most HDL-FC and nHDL-FC rapidly transfer directly to the liver independent of lecithin:cholesterol acyltransferase activity. A small fraction of plasma HDL-FC enters the trans-intestinal efflux pathway comprising direct FC transfer to the intestine. SR-B1 -/- mice, which have impaired trans-hepatic FC transport, are characterized by high plasma levels of a dysfunctional FC-rich HDL that increases plasma FC bioavailability in a way that produces whole-body hypercholesterolemia and multiple pathologies. The design of future therapeutic strategies to improve RCT will have to be formulated in the context of these dual RCT mechanisms and the role of FC bioavailability. Copyright © 2018 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  11. Properties of matter at ultra-high densities

    International Nuclear Information System (INIS)

    Banerjee, B.; Chitre, S.M.

    1975-01-01

    The recent discovery of pulsars and their subsequent identification with neutron stars has given a great impetus to the study of the behaviour of matter at ultra high densities. The object of these studies is to calculate the equation of state as a function of density. In this paper, the properties of electrically neutral, cold (T=0) matter at unusually high densities has been reviewed. The physics of the equation of state of such matter divides quite naturally in four density ranges. (i) At the very lowest densities the state of minimum energy is a lattice of 56 Fe atoms. This state persists upto 10 7 g/cm 3 . (ii) In the next density region the nuclei at the lattice sites become neutron rich because the high electron Fermi energy makes inverse beta decay possible. (iii) At a density 4.3 x 10 11 the nuclei become so neutron rich that the neutrons start 'dripping' out of the nuclei and form a gas. This density range is characterised by large, neutron-rich nuclei immersed in a neutron gas. (iv) At a density 2.4 x 10 14 g/cm 3 , the nuclei disappear and a fluid of uniform neutron matter with a small percentage of protons and electrons results. The above four density ranges have been discussed in detail as the equation of state is now well established upto the nuclear density 3 x 10 14 g/cm 3 . The problems of extending the equation of state beyond this density are also touched upon. (author)

  12. Pulsed high-density plasmas for advanced dry etching processes

    International Nuclear Information System (INIS)

    Banna, Samer; Agarwal, Ankur; Cunge, Gilles; Darnon, Maxime; Pargon, Erwine; Joubert, Olivier

    2012-01-01

    Plasma etching processes at the 22 nm technology node and below will have to satisfy multiple stringent scaling requirements of microelectronics fabrication. To satisfy these requirements simultaneously, significant improvements in controlling key plasma parameters are essential. Pulsed plasmas exhibit considerable potential to meet the majority of the scaling challenges, while leveraging the broad expertise developed over the years in conventional continuous wave plasma processing. Comprehending the underlying physics and etching mechanisms in pulsed plasma operation is, however, a complex undertaking; hence the full potential of this strategy has not yet been realized. In this review paper, we first address the general potential of pulsed plasmas for plasma etching processes followed by the dynamics of pulsed plasmas in conventional high-density plasma reactors. The authors reviewed more than 30 years of academic research on pulsed plasmas for microelectronics processing, primarily for silicon and conductor etch applications, highlighting the potential benefits to date and challenges in extending the technology for mass-production. Schemes such as source pulsing, bias pulsing, synchronous pulsing, and others in conventional high-density plasma reactors used in the semiconductor industry have demonstrated greater flexibility in controlling critical plasma parameters such as ion and radical densities, ion energies, and electron temperature. Specifically, plasma pulsing allows for independent control of ion flux and neutral radicals flux to the wafer, which is key to eliminating several feature profile distortions at the nanometer scale. However, such flexibility might also introduce some difficulty in developing new etching processes based on pulsed plasmas. Therefore, the main characteristics of continuous wave plasmas and different pulsing schemes are compared to provide guidelines for implementing different schemes in advanced plasma etching processes based on

  13. The glass transition in high-density amorphous ice.

    Science.gov (United States)

    Loerting, Thomas; Fuentes-Landete, Violeta; Handle, Philip H; Seidl, Markus; Amann-Winkel, Katrin; Gainaru, Catalin; Böhmer, Roland

    2015-01-01

    There has been a long controversy regarding the glass transition in low-density amorphous ice (LDA). The central question is whether or not it transforms to an ultraviscous liquid state above 136 K at ambient pressure prior to crystallization. Currently, the most widespread interpretation of the experimental findings is in terms of a transformation to a superstrong liquid above 136 K. In the last decade some work has also been devoted to the study of the glass transition in high-density amorphous ice (HDA) which is in the focus of the present review. At ambient pressure HDA is metastable against both ice I and LDA, whereas at > 0.2 GPa HDA is no longer metastable against LDA, but merely against high-pressure forms of crystalline ice. The first experimental observation interpreted as the glass transition of HDA was made using in situ methods by Mishima, who reported a glass transition temperature T g of 160 K at 0.40 GPa. Soon thereafter Andersson and Inaba reported a much lower glass transition temperature of 122 K at 1.0 GPa. Based on the pressure dependence of HDA's T g measured in Innsbruck, we suggest that they were in fact probing the distinct glass transition of very high-density amorphous ice (VHDA). Very recently the glass transition in HDA was also observed at ambient pressure at 116 K. That is, LDA and HDA show two distinct glass transitions, clearly separated by about 20 K at ambient pressure. In summary, this suggests that three glass transition lines can be defined in the p-T plane for LDA, HDA, and VHDA.

  14. Propofol Anesthesia and Sleep: A High-Density EEG Study

    Science.gov (United States)

    Murphy, Michael; Bruno, Marie-Aurelie; Riedner, Brady A.; Boveroux, Pierre; Noirhomme, Quentin; Landsness, Eric C.; Brichant, Jean-Francois; Phillips, Christophe; Massimini, Marcello; Laureys, Steven; Tononi, Giulio; Boly, Melanie

    2011-01-01

    Study Objectives: The electrophysiological correlates of anesthetic sedation remain poorly understood. We used high-density electroencephalography (hd-EEG) and source modeling to investigate the cortical processes underlying propofol anesthesia and compare them to sleep. Design: 256-channel EEG recordings in humans during propofol anesthesia. Setting: Hospital operating room. Patients or Participants: 8 healthy subjects (4 males) Interventions: N/A Measurements and Results: Initially, propofol induced increases in EEG power from 12–25 Hz. Loss of consciousness (LOC) was accompanied by the appearance of EEG slow waves that resembled the slow waves of NREM sleep. We compared slow waves in propofol to slow waves recorded during natural sleep and found that both populations of waves share similar cortical origins and preferentially propagate along the mesial components of the default network. However, propofol slow waves were spatially blurred compared to sleep slow waves and failed to effectively entrain spindle activity. Propofol also caused an increase in gamma (25–40 Hz) power that persisted throughout LOC. Source modeling analysis showed that this increase in gamma power originated from the anterior and posterior cingulate cortices. During LOC, we found increased gamma functional connectivity between these regions compared to the wakefulness. Conclusions: Propofol anesthesia is a sleep-like state and slow waves are associated with diminished consciousness even in the presence of high gamma activity. Citation: Murphy M; Bruno MA; Riedner BA; Boveroux P; Noirhomme Q; Landsness EC; Brichant JF; Phillips C; Massimini M; Laureys S; Tononi G; Boly M. Propofol anesthesia and sleep: a high-density EEG study. SLEEP 2011;34(3):283-291. PMID:21358845

  15. Memory, microprocessor, and ASIC

    CERN Document Server

    Chen, Wai-Kai

    2003-01-01

    System Timing. ROM/PROM/EPROM. SRAM. Embedded Memory. Flash Memories. Dynamic Random Access Memory. Low-Power Memory Circuits. Timing and Signal Integrity Analysis. Microprocessor Design Verification. Microprocessor Layout Method. Architecture. ASIC Design. Logic Synthesis for Field Programmable Gate Array (EPGA) Technology. Testability Concepts and DFT. ATPG and BIST. CAD Tools for BIST/DFT and Delay Faults.

  16. Hybdrid integral circuit for proportional chambers

    International Nuclear Information System (INIS)

    Yanik, R.; Khudy, M.; Povinets, P.; Strmen', P.; Grabachek, Z.; Feshchenko, A.A.

    1978-01-01

    Outlined briefly are a hybrid integrated circuit of the channel. One channel contains an input amplifier, delay circuit, and memory register on the base of the D-type flip-flop and controlled by the recording gate pulse. Provided at the output of the channel is a readout gating circuit. Presented are the flowsheet of the channel, the shaper amplifier and logical channel. At present the logical circuit was accepted for manufacture

  17. Effects of gamma irradiation on polypropylene, polypropylene + high density polyethylene and polypropylene + high density polyethylene + wood flour

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, J.; Albano, C.; Davidson, E.; Poleo, R. [Universidad Central de Venezuela, Caracas (Venezuela). Escuela de Quimica; Gonzalez, J.; Ichazo, M. [Universidad Simon Bolivar, Dept. de Mecanica, Caracas (Venezuela); Chipara, M. [Research Institute for Electrotechnics, Bucharest (Romania)

    2001-04-01

    The effect of the gamma-irradiation on the mechanical properties of the composites, Polypropylene (PP), PP+high density Polyethylene (HDPE), PP+ HDPE+wood flour, where HDPE is virgin and recycled, was studied. This paper discusses the behavior of the composites after exposure to various doses of gamma irradiation (1-7 MRads) in the presence of oxygen. The dependence of mechanical properties on the integral dose for a constant dose rate of 0.48 MRads/h confirms the influence of the irradiation. Strong effects on the elongation at break and break strength is noticed. The mathematical analysis suggests for the PP+r-HDPE a bimolecular process of the elongation at break. On the order hand, for the PP+HDPE a complex process is represented for a three exponential equation. (orig.)

  18. Effects of gamma irradiation on polypropylene, polypropylene + high density polyethylene and polypropylene + high density polyethylene + wood flour

    International Nuclear Information System (INIS)

    Reyes, J.; Albano, C.; Davidson, E.; Poleo, R.; Chipara, M.

    2001-01-01

    The effect of the gamma-irradiation on the mechanical properties of the composites, Polypropylene (PP), PP+high density Polyethylene (HDPE), PP+ HDPE+wood flour, where HDPE is virgin and recycled, was studied. This paper discusses the behavior of the composites after exposure to various doses of gamma irradiation (1-7 MRads) in the presence of oxygen. The dependence of mechanical properties on the integral dose for a constant dose rate of 0.48 MRads/h confirms the influence of the irradiation. Strong effects on the elongation at break and break strength is noticed. The mathematical analysis suggests for the PP+r-HDPE a bimolecular process of the elongation at break. On the order hand, for the PP+HDPE a complex process is represented for a three exponential equation. (orig.)

  19. Integrated circuit structure

    International Nuclear Information System (INIS)

    1981-01-01

    The invention describes the fabrication of integrated circuit structures, such as read-only memory components of field-effect transistors, which may be fabricated and then maintained in inventory, and later selectively modified in accordance with a desired pattern. It is claimed that MOS depletion-mode devices in accordance with the invention can be fabricated at lower cost and at higher yields. (U.K.)

  20. Auditory mismatch negativity in schizophrenia: topographic evaluation with a high-density recording montage.

    Science.gov (United States)

    Hirayasu, Y; Potts, G F; O'Donnell, B F; Kwon, J S; Arakaki, H; Akdag, S J; Levitt, J J; Shenton, M E; McCarley, R W

    1998-09-01

    The mismatch negativity, a negative component in the auditory event-related potential, is thought to index automatic processes involved in sensory or echoic memory. The authors' goal in this study was to examine the topography of auditory mismatch negativity in schizophrenia with a high-density, 64-channel recording montage. Mismatch negativity topography was evaluated in 23 right-handed male patients with schizophrenia who were receiving medication and in 23 nonschizophrenic comparison subjects who were matched in age, handedness, and parental socioeconomic status. The Positive and Negative Syndrome Scale was used to measure psychiatric symptoms. Mismatch negativity amplitude was reduced in the patients with schizophrenia. They showed a greater left-less-than-right asymmetry than comparison subjects at homotopic electrode pairs near the parietotemporal junction. There were correlations between mismatch negativity amplitude and hallucinations at left frontal electrodes and between mismatch negativity amplitude and passive-apathetic social withdrawal at left and right frontal electrodes. Mismatch negativity was reduced in schizophrenia, especially in the left hemisphere. This finding is consistent with abnormalities of primary or adjacent auditory cortex involved in auditory sensory or echoic memory.

  1. Wake High-Density Electroencephalographic Spatiospectral Signatures of Insomnia

    Science.gov (United States)

    Colombo, Michele A.; Ramautar, Jennifer R.; Wei, Yishul; Gomez-Herrero, Germán; Stoffers, Diederick; Wassing, Rick; Benjamins, Jeroen S.; Tagliazucchi, Enzo; van der Werf, Ysbrand D.; Cajochen, Christian; Van Someren, Eus J.W.

    2016-01-01

    Study Objectives: Although daytime complaints are a defining characteristic of insomnia, most EEG studies evaluated sleep only. We used high-density electroencephalography to investigate wake resting state oscillations characteristic of insomnia disorder (ID) at a fine-grained spatiospectral resolution. Methods: A case-control assessment during eyes open (EO) and eyes closed (EC) was performed in a laboratory for human physiology. Participants (n = 94, 74 female, 21–70 y) were recruited through www.sleepregistry.nl: 51 with ID, according to DSM-5 and 43 matched controls. Exclusion criteria were any somatic, neurological or psychiatric condition. Group differences in the spectral power topographies across multiple frequencies (1.5 to 40 Hz) were evaluated using permutation-based inference with Threshold-Free Cluster-Enhancement, to correct for multiple comparisons. Results: As compared to controls, participants with ID showed less power in a narrow upper alpha band (11–12.7 Hz, peak: 11.7 Hz) over bilateral frontal and left temporal regions during EO, and more power in a broad beta frequency range (16.3–40 Hz, peak: 19 Hz) globally during EC. Source estimates suggested global rather than cortically localized group differences. Conclusions: The widespread high power in a broad beta band reported previously during sleep in insomnia is present as well during eyes closed wakefulness, suggestive of a round-the-clock hyperarousal. Low power in the upper alpha band during eyes open is consistent with low cortical inhibition and attentional filtering. The fine-grained HD-EEG findings suggest that, while more feasible than PSG, wake EEG of short duration with a few well-chosen electrodes and frequency bands, can provide valuable features of insomnia. Citation: Colombo MA, Ramautar JR, Wei Y, Gomez-Herrero G, Stoffers D, Wassing R, Benjamins JS, Tagliazucchi E, van der Werf YD, Cajochen C, Van Someren EJW. Wake high-density electroencephalographic spatiospectral

  2. A review of emerging non-volatile memory (NVM) technologies and applications

    Science.gov (United States)

    Chen, An

    2016-11-01

    This paper will review emerging non-volatile memory (NVM) technologies, with the focus on phase change memory (PCM), spin-transfer-torque random-access-memory (STTRAM), resistive random-access-memory (RRAM), and ferroelectric field-effect-transistor (FeFET) memory. These promising NVM devices are evaluated in terms of their advantages, challenges, and applications. Their performance is compared based on reported parameters of major industrial test chips. Memory selector devices and cell structures are discussed. Changing market trends toward low power (e.g., mobile, IoT) and data-centric applications create opportunities for emerging NVMs. High-performance and low-cost emerging NVMs may simplify memory hierarchy, introduce non-volatility in logic gates and circuits, reduce system power, and enable novel architectures. Storage-class memory (SCM) based on high-density NVMs could fill the performance and density gap between memory and storage. Some unique characteristics of emerging NVMs can be utilized for novel applications beyond the memory space, e.g., neuromorphic computing, hardware security, etc. In the beyond-CMOS era, emerging NVMs have the potential to fulfill more important functions and enable more efficient, intelligent, and secure computing systems.

  3. INTEGRATED SENSOR EVALUATION CIRCUIT AND METHOD FOR OPERATING SAID CIRCUIT

    OpenAIRE

    Krüger, Jens; Gausa, Dominik

    2015-01-01

    WO15090426A1 Sensor evaluation device and method for operating said device Integrated sensor evaluation circuit for evaluating a sensor signal (14) received from a sensor (12), having a first connection (28a) for connection to the sensor and a second connection (28b) for connection to the sensor. The integrated sensor evaluation circuit comprises a configuration data memory (16) for storing configuration data which describe signal properties of a plurality of sensor control signals (26a-c). T...

  4. A precision timing discriminator for high density detector systems

    International Nuclear Information System (INIS)

    Turko, B.T.; Smith, R.C.

    1992-01-01

    Most high resolution time measurement techniques require discriminators that accurately make the time arrival of events regardless of their intensity. Constant fraction discriminators or zero-crossing discriminators are generally used. In this paper, the authors describe a zero-crossing discriminator that accurately determines the peak of a quasi-Gaussian waveform by differentiating it and detecting the resulting zero-crossing. Basically, it consists of a fast voltage comparator and tow integrating networks: an RC section and an LR section used in a way that keeps the input impedance purely resistive. A time walk of 100 ps in an amplitude range exceeding 100:1 has been achieved for wave-forms from 1.5 ns to 15 ns FWHM. An arming level discriminator is added to eliminate triggering by noise. Easily implemented in either monolithic or hybrid technology, the circuit is suitable for large multichannel detector systems where size and power dissipation are crucial. Circuit diagrams and typical measured data are also presented

  5. Using NEG-pumping near a high density internal target

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, Alexander; Marton, Johann; Widmann, Eberhard; Zmeskal, Johann [Stefan Meyer Institut fuer Subatomare Physik, OeAW (Germany); Orth, Herbert [GSI, Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany)

    2009-07-01

    The universal detector PANDA will be constructed at the future high-energy antiproton storage ring HESR at FAIR (Facility for Antiproton and Ion Research, GSI/Darmstadt). It will use antiproton beams (1.5 to 15 GeV/c) for hadron physics in the charmonium region. The Stefan Meyer Institut (SMI) contributes to major parts of the PANDA detector like the hydrogen cluster-jet target and the vacuum system of the antiproton - target interaction zone. To ensure low background, the residual gas load in the interaction zone and in the antiproton beam-pipe has to be minimised. Most of the gas load will come from the high density internal hydrogen target. As the detector will cover almost the full solid angle, the installation of pumps near the interaction zone is impossible. Therefore the use of NEG (non-evaporative-getter) coated beam pipes has been considered as an alternative. Two setups with NEG coated tubes have been installed at SMI as prototypes of the PANDA interaction zone. General parameters of the NEG-film, its outgassing behaviour, the pumping speed and the pumping capacity for hydrogen have been tested. The results of the studies on the PANDA-interaction region are presented.

  6. Statistical mechanics of high-density bond percolation

    Science.gov (United States)

    Timonin, P. N.

    2018-05-01

    High-density (HD) percolation describes the percolation of specific κ -clusters, which are the compact sets of sites each connected to κ nearest filled sites at least. It takes place in the classical patterns of independently distributed sites or bonds in which the ordinary percolation transition also exists. Hence, the study of series of κ -type HD percolations amounts to the description of classical clusters' structure for which κ -clusters constitute κ -cores nested one into another. Such data are needed for description of a number of physical, biological, and information properties of complex systems on random lattices, graphs, and networks. They range from magnetic properties of semiconductor alloys to anomalies in supercooled water and clustering in biological and social networks. Here we present the statistical mechanics approach to study HD bond percolation on an arbitrary graph. It is shown that the generating function for κ -clusters' size distribution can be obtained from the partition function of the specific q -state Potts-Ising model in the q →1 limit. Using this approach we find exact κ -clusters' size distributions for the Bethe lattice and Erdos-Renyi graph. The application of the method to Euclidean lattices is also discussed.

  7. Low fasting low high-density lipoprotein and postprandial lipemia

    Directory of Open Access Journals (Sweden)

    Sorodila Konstandina

    2004-07-01

    Full Text Available Abstract Background Low levels of high density lipoprotein (HDL cholesterol and disturbed postprandial lipemia are associated with coronary heart disease. In the present study, we evaluated the variation of triglyceride (TG postprandially in respect to serum HDL cholesterol levels. Results Fifty two Greek men were divided into 2 main groups: a the low HDL group (HDL p = 0.002. The low HDL group had significantly higher TG at 4, 6 and 8 h postprandially compared to the controls (p = 0.006, p = 0.002, and p p = 0.017 compared to the matched-control group. ROC analysis showed that fasting TG ≥ 121 mg/dl have 100% sensitivity and 81% specificity for an abnormal TG response (auc = 0.962, p Conclusions The delayed TG clearance postprandially seems to result in low HDL cholesterol even in subjects with low fasting TG. The fasting TG > 121 mg/dl are predictable for abnormal response to fatty meal.

  8. High density turbulent plasma processes from a shock tube

    International Nuclear Information System (INIS)

    Oyedeji, O.; Johnson, J.A. III

    1991-01-01

    We have finished the first stages of our experimental and theoretical investigations on models for energy and momentum transport and for photon-particle collision processes in a turbulent quasi-stationary high density plasma. The system is explored by beginning to determine the turbulence phenomenology associated with an ionizing shock wave. The theoretical underpinnings are explored for phonon particle collisions by determining the collisional redistribution function, using Lioville Space Green's Function, which will characterize the inelastic scattering of the radiation from one frequency to another. We have observed that a weak magnetic field tends to increase the apparent random-like behaviors in a collisional turbulent plasma. On the theoretical side, we have been able to achieve a form for the collisional redistribution function. It remains to apply these concepts to a stationary turbulent plasma in the reflected ionizing shock wave and to exercise the implications of evaluations of the collisional redistribution function for such a system when it is probed by a strong radiation source. These results are discussed in detail in the publications, which have resulted from the this effort, cited at the end of the report

  9. Irradiation testing of high density uranium alloy dispersion fuels

    International Nuclear Information System (INIS)

    Hayes, S.L.; Trybus, C.L.; Meyer, M.K.

    1997-10-01

    Two irradiation test vehicles have been designed, fabricated, and inserted into the Advanced Test Reactor in Idaho. Irradiation of these experiments began in August 1997. These irradiation tests were designed to obtain irradiation performance information on a variety of potential new, high-density dispersion fuels. Each of the two irradiation vehicles contains 32 microplates. Each microplate is aluminum clad, having an aluminum matrix phase and containing one of the following compositions as the fuel phase: U-10Mo, U-8Mo, U-6Mo, U-4Mo, U-9Nb-3Zr, U-6Nb-4Zr, U-5Nb-3Zr, U-6Mo-1Pt, U-6Mo-0.6Ru, U-10Mo-0.05Sn, U 2 Mo, or U 3 Si 2 . These experiments will be discharged at peak fuel burnups of 40% and 80%. Of particular interest is the fission gas retention/swelling characteristics of these new fuel alloys. This paper presents the design of the irradiation vehicles and the irradiation conditions

  10. High-field, high-density tokamak power reactor

    International Nuclear Information System (INIS)

    Cohn, D.R.; Cook, D.L.; Hay, R.D.; Kaplan, D.; Kreischer, K.; Lidskii, L.M.; Stephany, W.; Williams, J.E.C.; Jassby, D.L.; Okabayashi, M.

    1977-11-01

    A conceptual design of a compact (R 0 = 6.0 m) high power density (average P/sub f/ = 7.7 MW/m 3 ) tokamak demonstration power reactor has been developed. High magnetic field (B/sub t/ = 7.4 T) and moderate elongation (b/a = 1.6) permit operation at the high density (n(0) approximately 5 x 10 14 cm -3 ) needed for ignition in a relatively small plasma, with a spatially-averaged toroidal beta of only 4%. A unique design for the Nb 3 Sn toroidal-field magnet system reduces the stress in the high-field trunk region, and allows modularization for simpler disassembly. The modest value of toroidal beta permits a simple, modularized plasma-shaping coil system, located inside the TF coil trunk. Heating of the dense central plasma is attained by the use of ripple-assisted injection of 120-keV D 0 beams. The ripple-coil system also affords dynamic control of the plasma temperature during the burn period. A FLIBE-lithium blanket is designed especially for high-power-density operation in a high-field environment, and gives an overall tritium breeding ratio of 1.05 in the slowly pumped lithium

  11. [Residual risk: The roles of triglycerides and high density lipoproteins].

    Science.gov (United States)

    Grammer, Tanja; Kleber, Marcus; Silbernagel, Günther; Scharnagl, Hubert; März, Winfried

    2016-06-01

    In clinical trials, the reduction of LDL-cholesterol (LDL-C) with statins reduces the incidence rate of cardiovascular events by approximately one third. This means, that a sizeable "residual risk" remains. Besides high lipoprotein (a), disorders in the metabolism of triglyceride-rich lipoproteins and high density liproteins have been implicated as effectors of the residual risk. Both lipoprotein parameters correlate inversely with each other. Therefore, the etiological contributions of triglycerides and / or of HDL for developing cardiovascular disease can hardly be estimated from either observational studies or from intervention studies. The largely disappointing results of intervention studies with inhibitors of the cholesteryl ester transfer protein and in particular the available set of genetically-epidemiological studies suggest that in the last decade, the importance of HDL cholesterol has been overvalued, while the importance of triglycerides has been underestimated. High triglycerides not always atherogenic, but only if they are associated with the accumulation relatively cholesterol-enriched, incompletely catabolized remnants of chylomicrons and very low density lipoproteins (familial type III hyperlipidemia, metabolic syndrome, diabetes mellitus). The normalization of the concentration of triglycerides and remnants by inhibiting the expression of apolipoprotein C3 is hence a new, promising therapeutic target. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Silicon micromachining using a high-density plasma source

    International Nuclear Information System (INIS)

    McAuley, S.A.; Ashraf, H.; Atabo, L.; Chambers, A.; Hall, S.; Hopkins, J.; Nicholls, G.

    2001-01-01

    Dry etching of Si is critical in satisfying the demands of the micromachining industry. The micro-electro-mechanical systems (MEMS) community requires etches capable of high aspect ratios, vertical profiles, good feature size control and etch uniformity along with high throughput to satisfy production requirements. Surface technology systems' (STS's) high-density inductively coupled plasma (ICP) etch tool enables a wide range of applications to be realized whilst optimizing the above parameters. Components manufactured from Si using an STS ICP include accelerometers and gyroscopes for military, automotive and domestic applications. STS's advanced silicon etch (ASE TM ) has also allowed the first generation of MEMS-based optical switches and attenuators to reach the marketplace. In addition, a specialized application for fabricating the next generation photolithography exposure masks has been optimized for 200 mm diameter wafers, to depths of ∼750 μm. Where the profile is not critical, etch rates of greater than 8 μm min -1 have been realized to replace previous methods such as wet etching. This is also the case for printer applications. Specialized applications that require etching down to pyrex or oxide often result in the loss of feature size control at the interface; this is an industry wide problem. STS have developed a technique to address this. The rapid progression of the industry has led to development of the STS ICP etch tool, as well as the process. (author)

  13. High-Density Infrared Surface Treatments of Refractories

    Energy Technology Data Exchange (ETDEWEB)

    Tiegs, T.N.

    2005-03-31

    Refractory materials play a crucial role in all energy-intensive industries and are truly a crosscutting technology for the Industries of the Future (IOF). One of the major mechanisms for the degradation of refractories and a general decrease in their performance has been the penetration and corrosion by molten metals or glass. Methods and materials that would reduce the penetration, wetting, and corrosive chemistry would significantly improve refractory performance and also maintain the quality of the processed liquid, be it metal or glass. This report presents the results of an R&D project aimed at investigating the use of high-density infrared (HDI) heating to surface treat refractories to improve their performance. The project was a joint effort between Oak Ridge National Laboratory (ORNL) and the University of Missouri-Rolla (UMR). HDI is capable of heating the near-surface region of materials to very high temperatures where sintering, diffusion, and melting can occur. The intended benefits of HDI processing of refractories were to (1) reduce surface porosity (by essentially sealing the surface to prevent liquid penetration), (2) allow surface chemistry changes to be performed by bonding an adherent coating onto the underlying refractory (in order to inhibit wetting and/or improve corrosion resistance), and (3) produce noncontact refractories with high-emissivity surface coatings.

  14. Postirradiation examination of high-density uranium alloy dispersion fuels

    International Nuclear Information System (INIS)

    Hayes, S.L.; Meyer, M.K.; Hofman, G.L.; Strain, R.V.

    1998-01-01

    Two irradiation test vehicles, designated RERTR-2, were inserted into the Advanced Test reactor in Idaho in August 1997. These tests were designed to obtain irradiation performance information on a variety of potential new, high-density uranium alloy dispersion fuels, including U-10Mo, U-8Mo, U-6Mo, U-4Mo, U-9Nb-3Zr, U-6Nb-4Zr, U-5Nb-3Zr, U-6Mo-1Pt, U-6Mo-0.6Ru and U-10Mo-0.05Sn: the intermetallic compounds U 2 Mo and U-10Mo-0.-5Sn; the intermetallic compounds U 2 Mo and U 3 Si 2 were also included in the fuel test matrix. These fuels are included in the experiments as microplates (76 mm x 22 mm x 1.3mm outer dimensions) with a nominal fuel volume loading of 25% and irradiated at relatively low temperature (∼100 deg C). RERTR-1 and RERTR-2 were discharged from the reactor in November 1997 and July 1998, respectively at calculated peak fuel burnups of 45 and 71 at %-U 235 Both experiments are currently under examination at the Alpha Gamma Hot Cell Facility at Argonne National Laboratory in Chicago. This paper presents the postirradiation examination results available to date from these experiments. (author)

  15. High-density polyethylene dosimetry by transvinylene FTIR analysis

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Silverman, J.; Al-Sheikhly, M.

    1999-01-01

    and electrons. The useful dose range of 0.053 cm thick high-density polyethylene film (rho = 0.961 g cm(-3); melt index = 0.8 dg min(-1)), for irradiations by (60)Co gamma radiation and 2.0 and 0.4 MeV electron beams in deaerated atmosphere (Na gas), is about 50-10(3) kGy for FTIR transvinylene......The formation of transvinylene unsaturation, -CH=CH-, due to free-radical or cationic-initiated dehydrogenation by irradiation, is a basic reaction in polyethylene and is useful for dosimetry at high absorbed doses. The radiation-enhanced infrared absorption having a maximum at nu = 965 cm......(-l) (lambda = 10.36 mu m) is stable in air and can be measured by Fourier-transform infrared (FTIR) spectrophotometry. The quantitative analysis is a useful means of product end-point dosimetry for radiation processing with gamma rays and electrons, where polyethylene is a component of the processed product...

  16. High Density Lipoprotein: A Therapeutic Target in Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Philip J. Barter

    2013-09-01

    Full Text Available High density lipoproteins (HDLs have a number of properties that have the potential to inhibit the development of atherosclerosis and thus reduce the risk of having a cardiovascular event. These protective effects of HDLs may be reduced in patients with type 2 diabetes, a condition in which the concentration of HDL cholesterol is frequently low. In addition to their potential cardioprotective properties, HDLs also increase the uptake of glucose by skeletal muscle and stimulate the synthesis and secretion of insulin from pancreatic β cells and may thus have a beneficial effect on glycemic control. This raises the possibility that a low HDL concentration in type 2 diabetes may contribute to a worsening of diabetic control. Thus, there is a double case for targeting HDLs in patients with type 2 diabetes: to reduce cardiovascular risk and also to improve glycemic control. Approaches to raising HDL levels include lifestyle factors such as weight reduction, increased physical activity and stopping smoking. There is an ongoing search for HDL-raising drugs as agents to use in patients with type 2 diabetes in whom the HDL level remains low despite lifestyle interventions.

  17. High-density matter: current status and future challenges

    Directory of Open Access Journals (Sweden)

    Stone J. R.

    2015-01-01

    Full Text Available There are many fascinating processes in the Universe which we observe in more and more in detail thanks to increasingly sophisticated technology. One of the most interesting phenomena is the life cycle of stars, their birth, evolution and death. If the stars are massive enough, they end their lives in the core-collapse supernova explosion, the one of the most violent events in the Universe. As the result, the densest objects in the Universe, neutron stars and/or black holes are created. Naturally, the physical basis of these events should be understood in line with observation. The current status of our knowledge of processes in the life of stars is far from adequate for their true understanding. We show that although many models have been constructed their detailed ability to describe observations is limited or non-existent. Furthermore the general failure of all models means that we cannot tell which are heading in the right direction. A possible way forward in modeling of high-density matter is outlined, exemplified by the quark-meson-coupling model (QMC. This model has a natural explanation for the saturation of nuclear forces and depends on very few adjustable parameters, strongly constrained by the underlying physics. Latest QMC results for compact objects and finite nuclei are presented.

  18. High-Density Quantum Sensing with Dissipative First Order Transitions.

    Science.gov (United States)

    Raghunandan, Meghana; Wrachtrup, Jörg; Weimer, Hendrik

    2018-04-13

    The sensing of external fields using quantum systems is a prime example of an emergent quantum technology. Generically, the sensitivity of a quantum sensor consisting of N independent particles is proportional to sqrt[N]. However, interactions invariably occurring at high densities lead to a breakdown of the assumption of independence between the particles, posing a severe challenge for quantum sensors operating at the nanoscale. Here, we show that interactions in quantum sensors can be transformed from a nuisance into an advantage when strong interactions trigger a dissipative phase transition in an open quantum system. We demonstrate this behavior by analyzing dissipative quantum sensors based upon nitrogen-vacancy defect centers in diamond. Using both a variational method and a numerical simulation of the master equation describing the open quantum many-body system, we establish the existence of a dissipative first order transition that can be used for quantum sensing. We investigate the properties of this phase transition for two- and three-dimensional setups, demonstrating that the transition can be observed using current experimental technology. Finally, we show that quantum sensors based on dissipative phase transitions are particularly robust against imperfections such as disorder or decoherence, with the sensitivity of the sensor not being limited by the T_{2} coherence time of the device. Our results can readily be applied to other applications in quantum sensing and quantum metrology where interactions are currently a limiting factor.

  19. High density operation on the HT-7 superconducting tokamak

    International Nuclear Information System (INIS)

    Xiang Gao

    2000-01-01

    The structure of the operation region has been studied in the HT-7 superconducting tokamak, and progress on the extension of the HT-7 ohmic discharge operation region is reported. A density corresponding to 1.2 times the Greenwald limit was achieved by RF boronization. The density limit appears to be connected to the impurity content and the edge parameters, so the best results are obtained with very clean plasmas and peaked electron density profiles. The peaking factors of electron density profiles for different current and line averaged densities were observed. The density behaviour and the fuelling efficiency for gas puffing (20-30%), pellet injection (70-80%) and molecular beam injection (40-50%) were studied. The core crash sawteeth and MHD behaviour, which were induced by an injected pellet, were observed and the events correlated with the change of current profile and reversed magnetic shear. The MARFE phenomena on HT-7 are summarized. The best correlation has been found between the total input ohmic power and the product of the edge line averaged density and Z eff . HT-7 could be easily operated in the high density region MARFE-free using RF boronization. (author)

  20. The physics of the high density Z-pinch

    International Nuclear Information System (INIS)

    Glasser, A.H.; Hammel, J.E.; Lewis, H.R.

    1988-01-01

    The fiber-initiated High-Density Z-Pinch (HDZP) is a novel concept in which fusion plasma could be produced by applying 2 MV along a thin filament of frozen deuterium, 20-30 μm in diameter, 5-10 cm long. The megamp-range currents that result would ohmically heat the fiber to fusion temperatures in 100 ns while maintaining nearly constant radius. The plasma pressure would be held stably by the self-magnetic field for many radial sound transit times during the current-rise phase while, in the case of D-T, a significant fraction of the fiber undergoes thermonuclear fusion. This paper presents results of Los Alamos HDZP studies. Existing and new experiments are described. A succession of theoretical studies, including 1D self-similar and numerical studies of the hot plasma phase, 1D and 2D numerical studies of the cold startup phase, and 3D numerical studies of stability in the hot regime, are then presented. 9 refs., 4 figs

  1. High-density housing that works for all

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Arif

    2010-03-15

    In an urbanising world, the way people fit into cities is vastly important - socially, economically, environmentally, even psychologically. So density, or the number of people living in a given area, is central to urban design and planning. Both governments and markets tend to get density wrong, leading to overcrowding, urban sprawl or often both. A case in point are the high-rise buildings springing up throughtout urban Asia - perceived as key features of that widely touted concept, the 'world-class city'. While some may offer a viable solution to land pressures and density requirements, many built to house evicted or resettled 'slum' dwellers are a social and economic nightmare - inconveniently sited, overcrowded and costly. New evidence from Karachi, Pakistan, reveals a real alternative. Poor people can create liveable high-density settlements as long as community control, the right technical assistance and flexible designs are in place. A city is surely 'world-class' only when it is cosmopolitan – built to serve all, including the poorest.

  2. High-Density Superconducting Cables for Advanced ACTPol

    Science.gov (United States)

    Pappas, C. G.; Austermann, J.; Beall, J. A.; Duff, S. M.; Gallardo, P. A.; Grace, E.; Henderson, S. W.; Ho, S. P.; Koopman, B. J.; Li, D.; McMahon, J.; Nati, F.; Niemack, M. D.; Niraula, P.; Salatino, M.; Schillaci, A.; Schmitt, B. L.; Simon, S. M.; Staggs, S. T.; Stevens, J. R.; Vavagiakis, E. M.; Ward, J. T.; Wollack, E. J.

    2016-07-01

    Advanced ACTPol (AdvACT) is an upcoming Atacama Cosmology Telescope (ACT) receiver upgrade, scheduled to deploy in 2016, that will allow measurement of the cosmic microwave background polarization and temperature to the highest precision yet with ACT. The AdvACT increase in sensitivity is partly provided by an increase in the number of transition-edge sensors (TESes) per array by up to a factor of two over the current ACTPol receiver detector arrays. The high-density AdvACT TES arrays require 70 \\upmu m pitch superconducting flexible cables (flex) to connect the detector wafer to the first-stage readout electronics. Here, we present the flex fabrication process and test results. For the flex wiring layer, we use a 400-nm-thick sputtered aluminum film. In the center of the cable, the wiring is supported by a polyimide substrate, which smoothly transitions to a bare (uncoated with polyimide) silicon substrate at the ends of the cable for a robust wedge wire-bonding interface. Tests on the first batch of flex made for the first AdvACT array show that the flex will meet the requirements for AdvACT, with a superconducting critical current above 1 mA at 500 mK, resilience to mechanical and cryogenic stress, and a room temperature yield of 97 %.

  3. High-Density Quantum Sensing with Dissipative First Order Transitions

    Science.gov (United States)

    Raghunandan, Meghana; Wrachtrup, Jörg; Weimer, Hendrik

    2018-04-01

    The sensing of external fields using quantum systems is a prime example of an emergent quantum technology. Generically, the sensitivity of a quantum sensor consisting of N independent particles is proportional to √{N }. However, interactions invariably occurring at high densities lead to a breakdown of the assumption of independence between the particles, posing a severe challenge for quantum sensors operating at the nanoscale. Here, we show that interactions in quantum sensors can be transformed from a nuisance into an advantage when strong interactions trigger a dissipative phase transition in an open quantum system. We demonstrate this behavior by analyzing dissipative quantum sensors based upon nitrogen-vacancy defect centers in diamond. Using both a variational method and a numerical simulation of the master equation describing the open quantum many-body system, we establish the existence of a dissipative first order transition that can be used for quantum sensing. We investigate the properties of this phase transition for two- and three-dimensional setups, demonstrating that the transition can be observed using current experimental technology. Finally, we show that quantum sensors based on dissipative phase transitions are particularly robust against imperfections such as disorder or decoherence, with the sensitivity of the sensor not being limited by the T2 coherence time of the device. Our results can readily be applied to other applications in quantum sensing and quantum metrology where interactions are currently a limiting factor.

  4. LTCC magnetic components for high density power converter

    Science.gov (United States)

    Lebourgeois, Richard; Labouré, Eric; Lembeye, Yves; Ferrieux, Jean-Paul

    2018-04-01

    This paper deals with multilayer magnetic components for power electronics application and specifically for high frequency switching. New formulations based on nickel-zinc-copper spinel ferrites were developed for high power and high frequency applications. These ferrites can be sintered at low temperature (around 900°C) which makes them compatible with the LTCC (Low Temperature Co-fired Ceramics) technology. Metallic parts of silver or gold can be fully integrated inside the ferrite while guaranteeing the integrity of both the ferrite and the metal. To make inductors or transformers with the required properties, it is mandatory to have nonmagnetic parts between the turns of the winding. Then it is essential to find a dielectric material, which can be co-sintered both with the ferrite and the metal. We will present the solution we found to this problem and we will describe the results we obtained for a multilayer co-sintered transformer. We will see that these new components have good performance compared with the state of the art and are very promising for developing high density switching mode power supplies.

  5. Properties of recycled high density polyethylene and coffee dregs composites

    Directory of Open Access Journals (Sweden)

    Sibele Piedade Cestari

    2013-01-01

    Full Text Available Composites of recycled high density polyethylene (HDPE-R and coffee dregs (COFD were elaborated. The blends were made at the proportions of 100-0, 90-10, 80-20, 70-30, 60-40, 50-50 and 40-60% polymer-filler ratio. The materials were evaluated through scanning electron microscopy (SEM, differential scanning calorimetry (DSC, thermogravimetry/derivative thermogravimetry (TGA, and compressive resistance test. The compounding was done using a two-stage co-kneader system extruder, and then cylindrical specimens were injection molded. All composites had a fine dispersion of the COFD into the polymeric matrix. The composites degraded in two steps. The first one was in a temperature lower than the neat HDPE, but higher than the average processing temperature of the polymer. The melting temperature and the degree of crystallinity of the composites resulted similar to the neat HDPE ones. The compressive moduli of the composites resulted similar to the neat polymer one. The results show that these composites have interesting properties as a building material.

  6. Acrolein impairs the cholesterol transport functions of high density lipoproteins.

    Science.gov (United States)

    Chadwick, Alexandra C; Holme, Rebecca L; Chen, Yiliang; Thomas, Michael J; Sorci-Thomas, Mary G; Silverstein, Roy L; Pritchard, Kirkwood A; Sahoo, Daisy

    2015-01-01

    High density lipoproteins (HDL) are considered athero-protective, primarily due to their role in reverse cholesterol transport, where they transport cholesterol from peripheral tissues to the liver for excretion. The current study was designed to determine the impact of HDL modification by acrolein, a highly reactive aldehyde found in high abundance in cigarette smoke, on the cholesterol transport functions of HDL. HDL was chemically-modified with acrolein and immunoblot and mass spectrometry analyses confirmed apolipoprotein crosslinking, as well as acrolein adducts on apolipoproteins A-I and A-II. The ability of acrolein-modified HDL (acro-HDL) to serve as an acceptor of free cholesterol (FC) from COS-7 cells transiently expressing SR-BI was significantly decreased. Further, in contrast to native HDL, acro-HDL promotes higher neutral lipid accumulation in murine macrophages as judged by Oil Red O staining. The ability of acro-HDL to mediate efficient selective uptake of HDL-cholesteryl esters (CE) into SR-BI-expressing cells was reduced compared to native HDL. Together, the findings from our studies suggest that acrolein modification of HDL produces a dysfunctional particle that may ultimately promote atherogenesis by impairing functions that are critical in the reverse cholesterol transport pathway.

  7. Irradiation testing of high-density uranium alloy dispersion fuels

    International Nuclear Information System (INIS)

    Hayes, S.L.; Trybus, C.L.; Meyer, M.K.

    1997-01-01

    Two irradiation test vehicles have been designed, fabricated, and inserted into the Advanced Test Reactor in Idaho. Irradiation of these experiments began in August 1997. These irradiation tests were designed to obtain irradiation performance information on a variety of potential new, high-density dispersion fuels. Each of the two irradiation vehicles contains 32 'microplates'. Each microplate is aluminum clad, having an aluminum matrix phase and containing one of the following compositions as the fuel phase: U-10Mo, U-8Mo, U-6Mo, U-4Mo, U-9Nb-3Zr, U-6Nb-4Zr, U-5Nb-3Zr, U-6Mo-1Pt, U-6Mo-0.6Ru, U10Mo-0.05Sn, U2Mo, or U 3 Si 2 . These experiments will be discharged at peak fuel burnups of approximately 40 and 80 at.% U 235 . Of particular interest are the extent of reaction of the fuel and matrix phases and the fission gas retention/swelling characteristics of these new fuel alloys. This paper presents the design of the irradiation vehicles and the irradiation conditions. (author)

  8. High-Density Superconducting Cables for Advanced ACTPol

    Science.gov (United States)

    Pappas, C. G.; Austermann, J.; Beall, J. A.; Duff, S. M.; Gallardo, P. A.; Grace, E.; Henderson, S. W.; Ho, S. P.; Koopman, B. J.; Li, D.; hide

    2016-01-01

    Advanced ACTPol (AdvACT) is an upcoming Atacama Cosmology Telescope (ACT) receiver upgrade, scheduled to deploy in 2016, that will allow measure- ment of the cosmic microwave background polarization and temperature to the highest precision yet with ACT. The AdvACT increase in sensitivity is partly provided by an increase in the number of transition-edge sensors (TESes) per array by up to a factor of two over the current ACTPol receiver detector arrays. The high-density AdvACT TES arrays require 70 µ m pitch superconducting flexible cables (flex) to connect the detec- tor wafer to the first-stage readout electronics. Here, we present the flex fabrication process and test results. For the flex wiring layer, we use a 400-nm-thick sputtered alu- minum film. In the center of the cable, the wiring is supported by a polyimide substrate, which smoothly transitions to a bare (uncoated with polyimide) silicon substrate at the ends of the cable for a robust wedge wire-bonding interface. Tests on the first batch of flex made for the first AdvACT array show that the flex will meet the requirements for AdvACT, with a superconducting critical current above 1 mA at 500 mK, resilience to mechanical and cryogenic stress, and a room temperature yield of 97%.

  9. Inelastic neutron scattering from high-density fcc 4He

    International Nuclear Information System (INIS)

    Thomlinson, W.; Eckert, J.; Shirane, G.

    1978-01-01

    The phonon dispersion relations in high-density crystals of fcc 4 He have been measured along high-symmetry directions by the neutron-inelastic-scattering technique. A recent study of the lattice dynamics of fcc 4 He by Eckert et al. has been extended to cover the fcc phase diagram at pressures below 5 kbar. Molar volumes of 9.03, 9.43, and 9.97 cm 3 /mole have been studied in the temperature range from near the melting curve to near the fcc-hcp transition line. The phonon dispersion relations are in good agreement with a first-order self-consistent phonon theory calculation by Goldman. The observed phonon-group line shapes at large energy and momentum transfers show evidence for multiphonon scattering in agreement with calculations by Glyde. Eckert et al. reported extremely large anharmonic isochoric temperature shifts of the phonon energies. The present work studied the shifts as a function of molar volume and temperature. Mode-Grueneisen-parameter dispersion curves have been measured using the present data and earlier measurements at lower density in the fcc phase by Traylor et al. Macroscopic Grueneisen parameters have been calculated from the phonon density of states obtained from the data

  10. The infant mirror neuron system studied with high density EEG.

    Science.gov (United States)

    Nyström, Pär

    2008-01-01

    The mirror neuron system has been suggested to play a role in many social capabilities such as action understanding, imitation, language and empathy. These are all capabilities that develop during infancy and childhood, but the human mirror neuron system has been poorly studied using neurophysiological measures. This study measured the brain activity of 6-month-old infants and adults using a high-density EEG net with the aim of identifying mirror neuron activity. The subjects viewed both goal-directed movements and non-goal-directed movements. An independent component analysis was used to extract the sources of cognitive processes. The desynchronization of the mu rhythm in adults has been shown to be a marker for activation of the mirror neuron system and was used as a criterion to categorize independent components between subjects. The results showed significant mu desynchronization in the adult group and significantly higher ERP activation in both adults and 6-month-olds for the goal-directed action observation condition. This study demonstrate that infants as young as 6 months display mirror neuron activity and is the first to present a direct ERP measure of the mirror neuron system in infants.

  11. High-Density Stretchable Electrode Grids for Chronic Neural Recording.

    Science.gov (United States)

    Tybrandt, Klas; Khodagholy, Dion; Dielacher, Bernd; Stauffer, Flurin; Renz, Aline F; Buzsáki, György; Vörös, János

    2018-04-01

    Electrical interfacing with neural tissue is key to advancing diagnosis and therapies for neurological disorders, as well as providing detailed information about neural signals. A challenge for creating long-term stable interfaces between electronics and neural tissue is the huge mechanical mismatch between the systems. So far, materials and fabrication processes have restricted the development of soft electrode grids able to combine high performance, long-term stability, and high electrode density, aspects all essential for neural interfacing. Here, this challenge is addressed by developing a soft, high-density, stretchable electrode grid based on an inert, high-performance composite material comprising gold-coated titanium dioxide nanowires embedded in a silicone matrix. The developed grid can resolve high spatiotemporal neural signals from the surface of the cortex in freely moving rats with stable neural recording quality and preserved electrode signal coherence during 3 months of implantation. Due to its flexible and stretchable nature, it is possible to minimize the size of the craniotomy required for placement, further reducing the level of invasiveness. The material and device technology presented herein have potential for a wide range of emerging biomedical applications. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Using NEG-pumping near a high density internal target

    International Nuclear Information System (INIS)

    Gruber, A.; Marton, J.; Widmann, E.; Zmeskal, J.; Orth, H.

    2008-01-01

    Full text: The Stefan Meyer Institut (SMI) is part of the international PANDA collaboration. The universal detector will be constructed at the future high-energy antiproton storage ring HESR at FAIR (Facility for Antiproton and Ion Research, GSI/Darmstadt). PANDA will use antiproton beams (1.5 to 15 GeV/c) for hadron physics in the charmonium region. SMI contributes to major parts of the PANDA detector like the hydrogen cluster-jet target and the vacuum system of the antiproton - target interaction zone. To ensure low background, the residual gas load in the interaction zone and in the antiproton beam-pipe has to be minimized. Most of the gas load, of course will come from the high density internal hydrogen target. Since the PANDA detector will cover almost the full solid angle, the installation of pumps near the interaction zone is impossible. Therefore, the use of NEG (non-evaporative-getter) coated beam pipes has been considered as an alternative. Two setups with NEG coated tubes have been installed at SMI as prototypes of the PANDA interaction zone. The outgassing behavior, the pumping speed and the pumping capacity for hydrogen have been tested. The status of the studies of the interaction region will be presented. (author)

  13. Resonance circuits for adiabatic circuits

    Directory of Open Access Journals (Sweden)

    C. Schlachta

    2003-01-01

    Full Text Available One of the possible techniques to reduces the power consumption in digital CMOS circuits is to slow down the charge transport. This slowdown can be achieved by introducing an inductor in the charging path. Additionally, the inductor can act as an energy storage element, conserving the energy that is normally dissipated during discharging. Together with the parasitic capacitances from the circuit a LCresonant circuit is formed.

  14. Experimental study of high density foods for the Space Operations Center

    Science.gov (United States)

    Ahmed, S. M.

    1981-01-01

    The experimental study of high density foods for the Space Operations Center is described. A sensory evaluation of the high density foods was conducted first to test the acceptability of the products. A shelf-life study of the high density foods was also conducted for three different time lengths at three different temperatures. The nutritional analysis of the high density foods is at present incomplete.

  15. Ultra-high Density SNParray in Neuroblastoma Molecular Diagnostics

    Directory of Open Access Journals (Sweden)

    Inge M. Ambros

    2014-08-01

    Full Text Available Neuroblastoma serves as a paradigm for applying tumor genomic data for determining patient prognosis and thus for treatment allocation. MYCN status, i.e. amplified vs. non-amplified, was one of the very first biomarkers in oncology to discriminate aggressive from less aggressive or even favorable clinical courses of neuroblastoma. However, MYCN amplification is by far not the only genetic change associated with unfavorable clinical courses: so called segmental chromosomal aberrations, i.e. gains or losses of chromosomal fragments, can also indicate tumor aggressiveness. The clinical use of these genomic aberrations has, however, been hampered for many years by methodical and interpretational problems. Only after reaching worldwide consensus on markers, methodology, and data interpretation, information on SCAs has recently been implemented in clinical studies. Now, a number of collaborative studies within COG, GPOH and SIOPEN use genomic information to stratify therapy for patients with localized and metastatic disease. Recently, new types of DNA based aberrations influencing the clinical behavior of neuroblastomas have been described. Deletions or mutations of genes like ATRX and a phenomenon referred to as chromothripsis are all assumed to correlate with an unfavorable clinical behavior. However, these genomic aberrations need to be scrutinized in larger studies applying the most appropriate techniques. Single nucleotide polymorphism (SNP arrays have proven successful in deciphering genomic aberrations of cancer cells; these techniques, however, are usually not applied in the daily routine. Here, we present an ultra-high density (UHD SNParray technique which is, because of its high specificity and sensitivity and the combined copy number and allele information, highly appropriate for the genomic diagnosis of neuroblastoma and other malignancies.

  16. High density microelectronics package using low temperature cofirable ceramics

    International Nuclear Information System (INIS)

    Fu, S.-L.; Hsi, C.-S.; Chen, L.-S.; Lin, W. K.

    1997-01-01

    Low Temperature Cofired Ceramics (LTCC) is a relative new thick film process and has many engineering and manufacturing advantages over both the sequential thick film process and high temperature cofired ceramic modules. Because of low firing temperature, low sheet resistance metal conductors, commercial thick film resistors, and thick film capacitors can be buried in or printed on the substrates. A 3-D multilayer ceramic substrate can be prepared via laminating and co-firing process. The packing density of the LTCC substrates can be increased by this 3-D packing technology. At Kaohsiung Polytechnic Institute (KPI), a LTCC substrate system has been developed for high density packaging applications, which had buried surface capacitors and resistors. The developed cordierite-glass ceramic substrate, which has similar thermal expansion as silicon chip, is a promising material for microelectronic packaging. When the substrates were sintered at temperatures between 850-900 degree centigrade, a relative density higher than 96 % can be obtained. The substrate had a dielectric constant between 5.5 and 6.5. Ruthenium-based resistor pastes were used for resistors purposes. The resistors fabricated in/on the LTCC substrates were strongly depended on the microstructures developed in the resistor films. Surface resistors were laser trimmed in order to obtain specific values for the resistors. Material with composition Pb(Fe 2/3 W 1/3 ) x (Fe l/2 Nb l/2 ) y Ti 2 O 3 was used as dielectric material of the capacitor in the substrate. The material can be sintered at temperatures between 850-930 degree centigrade, and has dielectric constant as high as 26000. After cofiring, good adhesion between dielectric and substrate layers was obtained. Combing the buried resistors and capacitors together with the lamination of LTCC layer, a 3-dimensional multilayered ceramic package was fabricated. (author)

  17. Ignition and burn in contaminated DT fuel at high densities

    International Nuclear Information System (INIS)

    Pasley, J.

    2010-01-01

    Complete text of publication follows. Radiation hydrodynamics simulations have been performed to quantify the effect of contamination upon the ignition threshold in DT at high densities. A detailed thermonuclear burn model, with multi-group multispecies ions, is incorporated alongside a multigroup diffusion approximation for thermal radiation transport. The code used is the research version of the HYADES 1D code. Acceptable levels of contamination are identified for a range of contaminant ion species. A range of different contaminant spatial distribution within the fuel are explored: i) in which the contamination is uniformly distributed throughout the fuel; ii) in which the impurity ions are confined to the hotspot, or iii) where contamination is restricted to a particular region of the hotspot (either centrally, near the surface, or at an intermediate location). Initially the fuel has a constant density with the hotspot located centrally. The overall radius of the fuel is chosen to be sufficiently large that it has no significant effect upon the success or failure of ignition. The evolution of the system is then simulated until ignition either establishes widespread thermonuclear burning, or a failure to ignite is observed. The critical ρr for ignition is found by iteration on the hotspot radius. We show that varying the spatial distribution of the contaminant within the ignition spot has little effect, so long as the total mass of contaminant is held the same. As expected, high-Z contamination is far more detrimental than that by low-Z ions. Discussion of the findings in the context of re-entrant cone-guided fast ignition is presented, in addition to a theoretical interpretation of the results.

  18. Degradation of high density lipoprotein in cultured rat luteal cells

    International Nuclear Information System (INIS)

    Rajan, V.P.; Menon, K.M.J.

    1986-01-01

    In rat ovary luteal cells, degradation of high density lipoprotein (HDL) to tricholoracetic acid (TCA)-soluble products accounts for only a fraction of the HDL-derived cholesterol used for steroidogenesis. In this study the authors have investigated the fate of 125 I]HDL bound to cultured luteal cells using pulse-chase technique. Luteal cell cultures were pulse labeled with [ 125 I]HDL 3 and reincubated in the absence of HDL. By 24 h about 50% of the initallay bound radioactivity was released into the medium, of which 60-65% could be precipitated with 10% TCA. Gel filtration of the chase incubation medium on 10% agarose showed that the amount of TCA-soluble radioactivity was nearly completely accounted for by a sharp peak in the low molecular weight region which was identified as 96% monoiodotyrosine by paper chromatography. The TCA-precipitable radioactivity was nearly completely accounted for by a sharp peak in the low molecular weight region which was identified as 96% monoiodotyrosine by paper chromatography. The TCA-precipitable radioactivity eluted over a wide range of molecular weights (15,000-80,000), and there was very little intact HDL present. Electrophoresis of the chase medium showed that component of the TCA-precipitable portion had mobility similar to apo AI. Lysosomal inhibitors of receptor-mediated endocytosis had no effect on the composition or quantity of radioactivity released during chase incubation. The results show that HDL 3 binding to luteal cells is followed by complete degradation of the lipoprotein, although the TCA-soluble part does not reflect the extent of degradation

  19. Surface interactions involved in flashover with high density electronegative gases.

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, Keith Conquest; Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Wallace, Zachariah Red; Lehr, Jane Marie

    2010-01-01

    This report examines the interactions involved with flashover along a surface in high density electronegative gases. The focus is on fast ionization processes rather than the later time ionic drift or thermalization of the discharge. A kinetic simulation of the gas and surface is used to examine electron multiplication and includes gas collision, excitation and ionization, and attachment processes, gas photoionization and surface photoemission processes, as well as surface attachment. These rates are then used in a 1.5D fluid ionization wave (streamer) model to study streamer propagation with and without the surface in air and in SF6. The 1.5D model therefore includes rates for all these processes. To get a better estimate for the behavior of the radius we have studied radial expansion of the streamer in air and in SF6. The focus of the modeling is on voltage and field level changes (with and without a surface) rather than secondary effects, such as, velocities or changes in discharge path. An experiment has been set up to carry out measurements of threshold voltages, streamer velocities, and other discharge characteristics. This setup includes both electrical and photographic diagnostics (streak and framing cameras). We have observed little change in critical field levels (where avalanche multiplication sets in) in the gas alone versus with the surface. Comparisons between model calculations and experimental measurements are in agreement with this. We have examined streamer sustaining fields (field which maintains ionization wave propagation) in the gas and on the surface. Agreement of the gas levels with available literature is good and agreement between experiment and calculation is good also. Model calculations do not indicate much difference between the gas alone versus the surface levels. Experiments have identified differences in velocity between streamers on the surface and in the gas alone (the surface values being larger).

  20. High density microelectronics package using low temperature cofirable ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Fu, S -L; Hsi, C -S; Chen, L -S; Lin, W K [Kaoshiung Polytechnic Institute Ta-Hsu, Kaoshiung (China)

    1998-12-31

    Low Temperature Cofired Ceramics (LTCC) is a relative new thick film process and has many engineering and manufacturing advantages over both the sequential thick film process and high temperature cofired ceramic modules. Because of low firing temperature, low sheet resistance metal conductors, commercial thick film resistors, and thick film capacitors can be buried in or printed on the substrates. A 3-D multilayer ceramic substrate can be prepared via laminating and co-firing process. The packing density of the LTCC substrates can be increased by this 3-D packing technology. At Kaohsiung Polytechnic Institute (KPI), a LTCC substrate system has been developed for high density packaging applications, which had buried surface capacitors and resistors. The developed cordierite-glass ceramic substrate, which has similar thermal expansion as silicon chip, is a promising material for microelectronic packaging. When the substrates were sintered at temperatures between 850-900 degree centigrade, a relative density higher than 96 % can be obtained. The substrate had a dielectric constant between 5.5 and 6.5. Ruthenium-based resistor pastes were used for resistors purposes. The resistors fabricated in/on the LTCC substrates were strongly depended on the microstructures developed in the resistor films. Surface resistors were laser trimmed in order to obtain specific values for the resistors. Material with composition Pb(Fe{sub 2/3}W{sub 1/3}){sub x}(Fe{sub l/2}Nb{sub l/2}){sub y}Ti{sub 2}O{sub 3} was used as dielectric material of the capacitor in the substrate. The material can be sintered at temperatures between 850-930 degree centigrade, and has dielectric constant as high as 26000. After cofiring, good adhesion between dielectric and substrate layers was obtained. Combing the buried resistors and capacitors together with the lamination of LTCC layer, a 3-dimensional multilayered ceramic package was fabricated. (author)

  1. Renewable carbohydrates are a potential high-density hydrogen carrier

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.-H. Percival [Biological Systems Engineering Department, 210-A Seitz Hall, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Institute for Critical Technology and Applied Sciences (ICTAS), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); DOE BioEnergy Science Center (BESC), Oak Ridge, TN 37831 (United States)

    2010-10-15

    The possibility of using renewable biomass carbohydrates as a potential high-density hydrogen carrier is discussed here. Gravimetric density of polysaccharides is 14.8 H{sub 2} mass% where water can be recycled from PEM fuel cells or 8.33% H{sub 2} mass% without water recycling; volumetric densities of polysaccharides are >100 kg of H{sup 2}/m{sup 3}. Renewable carbohydrates (e.g., cellulosic materials and starch) are less expensive based on GJ than are other hydrogen carriers, such as hydrocarbons, biodiesel, methanol, ethanol, and ammonia. Biotransformation of carbohydrates to hydrogen by cell-free synthetic (enzymatic) pathway biotransformation (SyPaB) has numerous advantages, such as high product yield (12 H{sub 2}/glucose unit), 100% selectivity, high energy conversion efficiency (122%, based on combustion energy), high-purity hydrogen generated, mild reaction conditions, low-cost of bioreactor, few safety concerns, and nearly no toxicity hazards. Although SyPaB may suffer from current low reaction rates, numerous approaches for accelerating hydrogen production rates are proposed and discussed. Potential applications of carbohydrate-based hydrogen/electricity generation would include hydrogen bioreactors, home-size electricity generators, sugar batteries for portable electronics, sugar-powered passenger vehicles, and so on. Developments in thermostable enzymes as standardized building blocks for cell-free SyPaB projects, use of stable and low-cost biomimetic NAD cofactors, and accelerating reaction rates are among the top research and development priorities. International collaborations are urgently needed to solve the above obstacles within a short time. (author)

  2. Pharmacologic management of isolated low high-density lipoprotein syndrome.

    Science.gov (United States)

    Bermúdez, Valmore; Cano, Raquel; Cano, Clímaco; Bermúdez, Fernando; Arraiz, Nailet; Acosta, Luis; Finol, Freddy; Pabón, María Rebeca; Amell, Anilsa; Reyna, Nadia; Hidalgo, Joaquin; Kendall, Paúl; Manuel, Velasco; Hernández, Rafael

    2008-01-01

    High-density lipoprotein (HDL) cholesterol is a heterogeneous group of lipoproteins exhibiting a variety of properties like prostacyclin production stimulation, decrease in platelet aggregation, endothelial cell apoptosis inhibition, and low-density lipoprotein oxidation blockade. Epidemiologic studies have shown an inverse relation between HDL cholesterol levels and cardiovascular risk. Low HDL cholesterol is associated with increased risk for myocardial infarction, stroke, sudden death, peripheral artery disease, and postangioplasty restenosis. In contrast, high HDL levels are associated with longevity and protection against atherosclerotic disease development. Given the evolving epidemic of obesity, diabetes mellitus, and metabolic syndrome, the prevalence of low HDL will continue to rise. In the United States, low HDL is present in 35% of men, 15% of women, and approximately 63% of patients with coronary artery disease. Data extracted from the Framingham study highlight that 1-mg increase in HDL levels decreases by 2% to 3% the risk of cardiovascular disease. There is no doubt regarding clinical importance about isolated low HDL, but relatively few clinicians consider a direct therapeutic intervention of this dyslipidemia. In this sense, lifestyle measures should be the first-line strategy to manage low HDL levels. On the other hand, pharmacologic options include niacin, fibrates, and statins. Fibrates appear to reduce risk preferentially in patients with low HDL with metabolic syndrome, whereas statins reduce risk across all levels of HDL. Torcetrapib, a cholesteryl esters transfer protein inhibitor, represented a hope to raise this lipoprotein; however, all clinical trials on this drug had ceased after ILLUMINATE, RADIANCE and ERASE trials had recorded an increase in mortality, rates of myocardial infarction, angina, and heart failure. In the near future, drugs as beta-glucans, Apo-A1 mimetic peptides, and ACAT inhibitors, are the new promises to treat this

  3. Neutron shielding properties of a new high-density concrete

    International Nuclear Information System (INIS)

    Lorente, A.; Gallego, E.; Vega Carrillo, H.R.; Mendez, R.

    2008-01-01

    The neutron shielding properties of a new high-density concrete (commercially available under the name Hormirad TM , developed in Spain by the company CT-RAD) have been characterized both experimentally and by Monte Carlo calculations. The shielding properties of this concrete against photons were previously studied and the material is being used to build bunkers, mazes and doors in medical accelerator facilities with good overall results. In this work, the objective was to characterize the material behaviour against neutrons, as well as to test alternative mixings including boron compounds in an effort to improve neutron shielding efficiency. With that purpose, Hormirad TM slabs of different thicknesses were exposed to an 241 Am-Be neutron source under controlled conditions in the neutron measurements laboratory of the Nuclear Engineering Department at UPM. The original mix, which includes a high fraction of magnetite, was then modified by adding different proportions of anhydrous borax (Na 2 B 4 O 7 ). In order to have a reference against common concrete used to shield medical accelerator facilities, the same experiment was repeated with ordinary (HA-25) concrete slabs. In parallel to the experiments, Monte Carlo calculations of the experiments were performed with MCNP5. The experimental results agree reasonably well with the Monte Carlo calculations. Therefore, the first and equilibrium tenth-value layers have been determined for the different types of concrete tested. The results show an advantageous behaviour of the Hormirad TM concrete, in terms of neutron attenuation against real thickness of the shielding. Borated concretes seem less practical since they did not show better neutron attenuation with respect to real thickness and their structural properties are worse. The neutron attenuation properties of Hormirad TM for typical neutron spectra in clinical LINAC accelerators rooms have been also characterized by Monte Carlo calculation. (author)

  4. Deposition and characterisation of copper for high density interconnects

    International Nuclear Information System (INIS)

    McCusker, N.

    1999-09-01

    Copper has been deposited by sputtering and investigated for application as high density interconnects, with a view to maximising its performance and reliability. A sputter deposition process using gettering has been developed, which produces consistently pure, low resistivity films. A relationship between film thickness and resistivity has been explained by studying the grain growth process in copper films using atomic force microscopy. The Maydas-Shatzkes model has been used to separate the contributions of grain boundary and surface scattering to thin film resistivity, in copper and gold. Stress and texture in copper film have been studied. Annealing has been used to promote grain growth and texture development. Electromigration has been studied in copper and aluminium interconnects using a multi-line accelerated test set-up. A difference in failure distributions and void morphologies has been explained by an entirely different damage mechanism. The importance of surface/interface migration in electromigration damage of copper lines has been established and explained using a grain boundary-grooving model. A tantalum overlayer was found to extend the lifetime of copper lines. A composite sputtering target has been used to deposit copper/zirconium alloy films. The composition of the alloys was studied by Rutherford backscattering, Auger and secondary neutral mass spectrometry. The alloy films had an improved electromigration lifetime. A surface controlled mechanism is proposed to explain the advantage. A metal oxide semiconductor (MOS) capacitor technique is used to investigate barrier reliability. Tungsten is shown to be an effective diffusion barrier for copper, up to 700 deg. C. (author)

  5. Modelling high density phenomena in hydrogen fibre Z-pinches

    International Nuclear Information System (INIS)

    Chittenden, J.P.

    1990-09-01

    The application of hydrogen fibre Z-pinches to the study of the radiative collapse phenomenon is studied computationally. Two areas of difficulty, the formation of a fully ionized pinch from a cryogenic fibre and the processes leading to collapse termination, are addressed in detail. A zero-D model based on the energy equation highlights the importance of particle end losses and changes in the Coulomb logarithm upon collapse initiation and termination. A 1-D Lagrangian resistive MHD code shows the importance of the changing radial profile shapes, particularly in delaying collapse termination. A 1-D, three fluid MHD code is developed to model the ionization of the fibre by thermal conduction from a high temperature surface corona to the cold core. Rate equations for collisional ionization, 3-body recombination and equilibration are solved in tandem with fluid equations for the electrons, ions and neutrals. Continuum lowering is found to assist ionization at the corona-core interface. The high density plasma phenomena responsible for radiative collapse termination are identified as the self-trapping of radiation and free electron degeneracy. A radiation transport model and computational analogues for the effects of degeneracy upon the equation of state, transport coefficients and opacity are implemented in the 1-D, single fluid model. As opacity increases the emergent spectrum is observed to become increasingly Planckian and a fall off in radiative cooling at small radii and low frequencies occurs giving rise to collapse termination. Electron degeneracy terminates radiative collapse by supplementing the radial pressure gradient until the electromagnetic pinch force is balanced. Collapse termination is found to be a hybrid process of opacity and degeneracy effects across a wide range of line densities with opacity dominant at large line densities but with electron degeneracy becoming increasingly important at lower line densities. (author)

  6. Biomimetic High-Density Lipoproteins from a Gold Nanoparticle Template

    Science.gov (United States)

    Luthi, Andrea Jane

    For hundreds of years the field of chemistry has looked to nature for inspiration and insight to develop novel solutions for the treatment of human diseases. The ability of chemists to identify, mimic, and modifiy small molecules found in nature has led to the discovery and development of many important therapeutics. Chemistry on the nanoscale has made it possible to mimic natural, macromolecular structures that may also be useful for understanding and treating diseases. One example of such a structure is high-density lipoprotein (HDL). The goal of this work is to use a gold nanoparticle (Au NP) as a template to synthesize functional mimics of HDL and characterize their structure and function. Chapter 1 details the structure and function of natural HDL and how chemistry on the nanoscale provides new strategies for mimicking HDL. This Chapter also describes the first examples of using nanoparticles to mimic HDL. Chapter 2 reports the synthesis and characterization of biomimetic HDL using different sizes of Au NPs and different surface chemistries and how these variables can be used to tailor the properties of biomimetic HDL. From these studies the optimal strategy for synthesizing biomimetic HDL was determined. In Chapter 3, the optimization of the synthesis of biomimetic HDL is discussed as well as a full characterization of its structure. In addition, the work in this chapter shows that biomimetic HDL can be synthesized on a large scale without alterations to its structure or function. Chapter 4 focuses on understanding the pathways by which biomimetic HDL accepts cholesterol from macrophage cells. The results of these studies demonstrate that biomimetic HDL is able to accept cholesterol by both active and passive pathways of cholesterol efflux. In Chapter 5 the preliminary results of in vivo studies to characterize the pharmacokinetics and pharmacodynamics of biomimetic HDL are presented. These studies suggest that biomimetic HDL traffics through tissues prone to

  7. Electronic circuit encyclopedia 2

    International Nuclear Information System (INIS)

    Park, Sun Ho

    1992-10-01

    This book is composed of 15 chapters, which are amplification of weak signal and measurement circuit audio control and power amplification circuit, data transmission and wireless system, forwarding and isolation, signal converting circuit, counter and comparator, discriminator circuit, oscillation circuit and synthesizer, digital and circuit on computer image processing circuit, sensor drive circuit temperature sensor circuit, magnetic control and application circuit, motor driver circuit, measuring instrument and check tool and power control and stability circuit.

  8. Electronic circuit encyclopedia 2

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Ho

    1992-10-15

    This book is composed of 15 chapters, which are amplification of weak signal and measurement circuit audio control and power amplification circuit, data transmission and wireless system, forwarding and isolation, signal converting circuit, counter and comparator, discriminator circuit, oscillation circuit and synthesizer, digital and circuit on computer image processing circuit, sensor drive circuit temperature sensor circuit, magnetic control and application circuit, motor driver circuit, measuring instrument and check tool and power control and stability circuit.

  9. Scalable Sub-micron Patterning of Organic Materials Toward High Density Soft Electronics.

    Science.gov (United States)

    Kim, Jaekyun; Kim, Myung-Gil; Kim, Jaehyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Woobin; Hwang, Chahwan; Moon, Juhyuk; Yang, Lin; Kim, Yun-Hi; Noh, Yong-Young; Jaung, Jae Yun; Kim, Yong-Hoon; Park, Sung Kyu

    2015-09-28

    The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. In this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. The successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.

  10. Using NVMe Gen3 PCIe SSD Cards in High-density Servers for High-performance Big Data Transfer Over Multiple Network Channels

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Chin [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-02-07

    This Technical Note describes how the Zettar team came up with a data transfer cluster design that convincingly proved the feasibility of using high-density servers for high-performance Big Data transfers. It then outlines the tests, operations, and observations that address a potential over-heating concern regarding the use of Non-Volatile Memory Host Controller Interface Specification (NVMHCI aka NVM Express or NVMe) Gen 3 PCIe SSD cards in high-density servers. Finally, it points out the possibility of developing a new generation of high-performance Science DMZ data transfer system for the data-intensive research community and commercial enterprises.

  11. Human endothelial progenitor cells internalize high-density lipoprotein.

    Directory of Open Access Journals (Sweden)

    Kaemisa Srisen

    Full Text Available Endothelial progenitor cells (EPCs originate either directly from hematopoietic stem cells or from a subpopulation of monocytes. Controversial views about intracellular lipid traffic prompted us to analyze the uptake of human high density lipoprotein (HDL, and HDL-cholesterol in human monocytic EPCs. Fluorescence and electron microscopy were used to investigate distribution and intracellular trafficking of HDL and its associated cholesterol using fluorescent surrogates (bodipy-cholesterol and bodipy-cholesteryl oleate, cytochemical labels and fluorochromes including horseradish peroxidase and Alexa Fluor® 568. Uptake and intracellular transport of HDL were demonstrated after internalization periods from 0.5 to 4 hours. In case of HDL-Alexa Fluor® 568, bodipy-cholesterol and bodipy-cholesteryl oleate, a photooxidation method was carried out. HDL-specific reaction products were present in invaginations of the plasma membrane at each time of treatment within endocytic vesicles, in multivesicular bodies and at longer periods of uptake, also in lysosomes. Some HDL-positive endosomes were arranged in form of "strings of pearl"- like structures. HDL-positive multivesicular bodies exhibited intensive staining of limiting and vesicular membranes. Multivesicular bodies of HDL-Alexa Fluor® 568-treated EPCs showed multilamellar intra-vacuolar membranes. At all periods of treatment, labeled endocytic vesicles and organelles were apparent close to the cell surface and in perinuclear areas around the Golgi apparatus. No HDL-related particles could be demonstrated close to its cisterns. Electron tomographic reconstructions showed an accumulation of HDL-containing endosomes close to the trans-Golgi-network. HDL-derived bodipy-cholesterol was localized in endosomal vesicles, multivesicular bodies, lysosomes and in many of the stacked Golgi cisternae and the trans-Golgi-network Internalized HDL-derived bodipy-cholesteryl oleate was channeled into the lysosomal

  12. High density internal transport barriers for burning plasma operation

    Energy Technology Data Exchange (ETDEWEB)

    Ridolfini, V Pericoli [Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Rome (Italy); Barbato, E [Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Rome (Italy); Buratti, P [Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Rome (Italy)] (and others)

    2005-12-15

    A tokamak plasma with internal transport barriers (ITBs) is the best candidate for a steady ITER operation, since the high energy confinement allows working at plasma currents (I{sub p}) lower than the reference scenario. To build and sustain an ITB at the ITER high density ({>=}10{sup 20} m{sup -3}) and largely dominant electron (e{sup -}) heating is not trivial in most existing tokamaks. FTU can instead meet both requests, thanks to its radiofrequency heating systems, lower hybrid (LH, up to 1.9 MW) and electron cyclotron (EC up to 1.2 MW). By the combined use of them, ITBs are obtained up to peak densities n{sub e0} > 1.3 x 10{sup 20} m{sup -3}, with central e{sup -} temperatures T{sub e0} {approx} 5.5 keV, and are sustained for as long as the heating pulse is applied (>35 confinement times, {tau}{sub E}). At n{sub e0} {approx} 0.8 x 10{sup 20} m{sup -3} T{sub e0} can be larger than 11 keV. Almost full current drive (CD) and an overall good steadiness is attained within about one {tau}{sub E}, 20 times faster than the ohmic current relaxation time. The ITB extends over a central region with an almost flat or slightly reversed q profile and q{sub min} {approx} 1.3 that is fully sustained by off-axis lower hybrid current drive. Consequent to this is the beneficial good alignment of the bootstrap current, generated by the ITB large pressure gradients, with the LH driven current. Reflectometry shows a clear change in the turbulence close to the ITB radius, consistent with the reduced e{sup -} transport. Ions (i{sup +}) are significantly heated via collisions, but thermal equilibrium with electrons cannot be attained since the e{sup -}-i{sup +} equipartition time is always 4-5 times longer than {tau}{sub E}. No degradation of the overall ion transport, rather a reduction of the i{sup +} heat diffusivity, is observed inside the ITB. The global confinement has been improved up to 1.6 times over the scaling predictions. The ITB radius can be controlled by adjusting the

  13. High density plasma heating in the Tokamak à configuration variable

    International Nuclear Information System (INIS)

    Curchod, L.

    2011-04-01

    The Tokamak à Configuration Variable (TCV) is a medium size magnetic confinement thermonuclear fusion experiment designed for the study of the plasma performances as a function of its shape. It is equipped with a high power and highly flexible electron cyclotron heating (ECH) and current drive (ECCD) system. Up to 3 MW of 2 nd harmonic EC power in ordinary (O 2 ) or extraordinary (X 2 ) polarization can be injected from TCV low-field side via six independently steerable launchers. In addition, up to 1.5 MW of 3 rd harmonic EC power (X 3 ) can be launched along the EC resonance from the top of TCV vacuum vessel. At high density, standard ECH and ECCD are prevented by the appearance of a cutoff layer screening the access to the EC resonance at the plasma center. As a consequence, less than 50% of TCV density operational domain is accessible to X 2 and X 3 ECH. The electron Bernstein waves (EBW) have been proposed to overcome this limitation. EBW is an electrostatic mode propagating beyond the plasma cutoff without upper density limit. Since it cannot propagate in vacuum, it has to be excited by mode conversion of EC waves in the plasma. Efficient electron Bernstein waves heating (EBH) and current drive (EBCD) were previously performed in several fusion devices, in particular in the W7-AS stellarator and in the MAST spherical tokamak. In TCV, the conditions for an efficient O-X-B mode conversion (i.e. a steep density gradient at the O 2 plasma cutoff) are met at the edge of high confinement (H-mode) plasmas characterized by the appearance of a pedestal in the electron temperature and density profiles. TCV experiments have demonstrated the first EBW coupling to overdense plasmas in a medium aspect-ratio tokamak via O-X-B mode conversion. This thesis work focuses on several aspects of ECH and EBH in low and high density plasmas. Firstly, the experimental optimum angles for the O-X-B mode conversion is successfully compared to the full-wave mode conversion calculation

  14. Swift heavy ion induced single event upsets in high density UV-EPROM's

    Energy Technology Data Exchange (ETDEWEB)

    Dahiwale, S.S. [Department of Physics, University of Pune, Pune 7 (India); Shinde, N.S. [Department of Chemical Engineering, Mie University (Japan); Kanjilal, D. [Inter University Accelerator Center, New Delhi (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 7 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 7 (India)], E-mail: sanjay@physics.unipune.ernet.in

    2008-04-15

    A few high density UV-EPROM's (32Kb x 8) were irradiated with 5.41 MeV energy {alpha}-particles with fluences from 10{sup 4} to 10{sup 8} alphas/cm{sup 2} and 100 MeV nickel, iodine and silver ions for low fluences between 5 x 10{sup 7} and 10{sup 8} ions/cm{sup 2}. The energy and ion species was selected on the basis of predicted threshold values of linear energy transfer (LET) in silicon. The program which was stored in the memory found to be changed from 0 to 1 and 1 to 0 state, respectively. On the basis of changed states, the cross-sections ({sigma}) were calculated to investigate the single event effects/upsets. No upset was observed in case of {alpha}-particle since it has very low LET, but the SEU cross-section found to be more in case of Iodine i.e. 2.29 x 10{sup -3} cm{sup 2} than that of nickel, 2.12 x 10{sup -3} cm{sup 2} and silver, 2.26 x 10{sup -3}. This mainly attributes that LET for iodine is more as compared to silver and nickel ions, which deposits large amount of energy near the sensitive node of memory cell in the form of electron-hole pairs required to change the state. These measured SEU cross-section were also compared with theoretically predicted values along with the Weibull distribution fit to the ion induced experimental SEU data. The theoretical predicted SEU cross-section 3.27 x 10{sup -3} cm{sup 2} found to be in good agreement with the measured SEU cross-section.

  15. Entrainment and high-density three-dimensional mapping in right atrial macroreentry provide critical complementary information: Entrainment may unmask "visual reentry" as passive.

    Science.gov (United States)

    Pathik, Bhupesh; Lee, Geoffrey; Nalliah, Chrishan; Joseph, Stephen; Morton, Joseph B; Sparks, Paul B; Sanders, Prashanthan; Kistler, Peter M; Kalman, Jonathan M

    2017-10-01

    With the recent advent of high-density (HD) 3-dimensional (3D) mapping, the utility of entrainment is uncertain. However, the limitations of visual representation and interpretation of these high-resolution 3D maps are unclear. The purpose of this study was to determine the strengths and limitations of both HD 3D mapping and entrainment mapping during mapping of right atrial macroreentry. Fifteen patients were studied. The number and type of circuits accounting for ≥90% of the tachycardia cycle length using HD 3D mapping were verified using systematic entrainment mapping. Entrainment sites with an unexpectedly long postpacing interval despite proximity to the active circuit were evaluated. Based on HD 3D mapping, 27 circuits were observed: 12 peritricuspid, 2 upper loop reentry, 10 lower loop reentry, and 3 lateral wall circuits. With entrainment, 17 of the 27 circuits were active: all 12 peritricuspid and 2 upper loop reentry. However, lower loop reentry was confirmed in only 3 of 10, and none of the 3 lateral wall circuits were present. Mean percentage of tachycardia cycle length covered by active circuits was 98% ± 1% vs 97% ± 2% for passive circuits (P = .09). None of the 345 entrainment runs terminated tachycardia or changed tachycardia mechanism. In 8 of 15 patients, 13 examples of unexpectedly long postpacing interval were observed at entrainment sites located distal to localized zones of slow conduction seen on HD 3D mapping. Using HD 3D mapping, "visual reentry" may be due to passive circuitous propagation rather than a critical reentrant circuit. HD 3D mapping provides new insights into regional conduction and helps explain unusual entrainment phenomena. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  16. Towards high-density matter with relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    Nagamiya, Shoji.

    1990-04-01

    Recent progress in nucleus-nucleus collisions at BNL and CERN suggests a hint that the formation of high-density nuclear matter could be possible with relativistic heavy-ion beams. What is the maximum density that can be achieved by heavy-ion collisions? Are there data which show evidence or hints on the formation of high density matter? Why is the research of high-density interesting? How about the future possibilities on this subject? These points are discussed. (author)

  17. High Channel Count, High Density Microphone Arrays for Wind Tunnel Environments, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Interdisciplinary Consulting Corporation (IC2) proposes the development of high channel count, high density, reduced cost per channel, directional microphone...

  18. Gap formation processes in a high-density plasma opening switch

    International Nuclear Information System (INIS)

    Grossmann, J.M.; Swanekamp, S.B.; Ottinger, P.F.; Commisso, R.J.; Hinshelwood, D.D.; Weber, B.V.

    1995-01-01

    A gap opening process in plasma opening switches (POS) is examined with the aid of numerical simulations. In these simulations, a high density (n e =10 14 --5x10 15 cm -3 ) uniform plasma initially bridges a small section of the coaxial transmission line of an inductive energy storage generator. A short section of vacuum transmission line connects the POS to a short circuit load. The results presented here extend previous simulations in the n e =10 12 --10 13 cm -3 density regime. The simulations show that a two-dimensional (2-D) sheath forms in the plasma near a cathode. This sheath is positively charged, and electrostatic sheath potentials that are large compared to the anode--cathode voltage develop. Initially, the 2-D sheath is located at the generator edge of the plasma. As ions are accelerated out of the sheath, it retains its original 2-D structure, but migrates axially toward the load creating a magnetically insulated gap in its wake. When the sheath reaches the load edge of the POS, the POS stops conducting current and the load current increases rapidly. At the end of the conduction phase a gap exists in the POS whose size is determined by the radial dimensions of the 2-D sheath. Simulations at various plasma densities and current levels show that the radial size of the gap scales roughly as B/n e , where B is the magnetic field. The results of this work are discussed in the context of long-conduction-time POS physics, but exhibit the same physical gap formation mechanisms as earlier lower density simulations more relevant to short-conduction-time POS. copyright 1995 American Institute of Physics

  19. Wireless sEMG System with a Microneedle-Based High-Density Electrode Array on a Flexible Substrate.

    Science.gov (United States)

    Kim, Minjae; Gu, Gangyong; Cha, Kyoung Je; Kim, Dong Sung; Chung, Wan Kyun

    2017-12-30

    Surface electromyography (sEMG) signals reflect muscle contraction and hence, can provide information regarding a user's movement intention. High-density sEMG systems have been proposed to measure muscle activity in small areas and to estimate complex motion using spatial patterns. However, conventional systems based on wet electrodes have several limitations. For example, the electrolyte enclosed in wet electrodes restricts spatial resolution, and these conventional bulky systems limit natural movements. In this paper, a microneedle-based high-density electrode array on a circuit integrated flexible substrate for sEMG is proposed. Microneedles allow for high spatial resolution without requiring conductive substances, and flexible substrates guarantee stable skin-electrode contact. Moreover, a compact signal processing system is integrated with the electrode array. Therefore, sEMG measurements are comfortable to the user and do not interfere with the movement. The system performance was demonstrated by testing its operation and estimating motion using a Gaussian mixture model-based, simplified 2D spatial pattern.

  20. Silicon integrated circuits part A : supplement 2

    CERN Document Server

    Kahng, Dawon

    1981-01-01

    Applied Solid State Science, Supplement 2: Silicon Integrated Circuits, Part A focuses on MOS device physics. This book is divided into three chapters-physics of the MOS transistor; nonvolatile memories; and properties of silicon-on-sapphire substrates devices, and integrated circuits. The topics covered include the short channel effects, MOSFET structures, floating gate devices, technology for nonvolatile semiconductor memories, sapphire substrates, and SOS integrated circuits and systems. The MOS capacitor, MIOS devices, and SOS process and device technology are also deliberated. This public

  1. Controllable circuit

    DEFF Research Database (Denmark)

    2010-01-01

    A switch-mode power circuit comprises a controllable element and a control unit. The controllable element is configured to control a current in response to a control signal supplied to the controllable element. The control unit is connected to the controllable element and provides the control...

  2. Circuit Training.

    Science.gov (United States)

    Nelson, Jane B.

    1998-01-01

    Describes a research-based activity for high school physics students in which they build an LC circuit and find its resonant frequency of oscillation using an oscilloscope. Includes a diagram of the apparatus and an explanation of the procedures. (DDR)

  3. Loss of activity-dependent Arc gene expression in the retrosplenial cortex after hippocampal inactivation: Interaction in a higher-order memory circuit

    Czech Academy of Sciences Publication Activity Database

    Kubík, Štěpán; Miyashita, T.; Kubik-Zahorodna, Agnieszka; Guzowski, J. F.

    2012-01-01

    Roč. 97, č. 1 (2012), s. 124-131 ISSN 1074-7427 Institutional research plan: CEZ:AV0Z50110509 Keywords : hippocampus * spatial memory * water maze * immediate-early gene * Arc * retrosplenial cortex Subject RIV: FH - Neurology Impact factor: 3.327, year: 2012

  4. Low voltage electroosmotic pump for high density integration into microfabricated fluidic systems

    NARCIS (Netherlands)

    Heuck, F.C.A.; Staufer, U.

    2011-01-01

    A low voltage electroosmotic (eo) pump suitable for high density integration into microfabricated fluidic systems has been developed. The high density integration of the eo pump required a small footprint as well as a specific on-chip design to ventilate the electrolyzed gases emerging at the

  5. Nanographene charge trapping memory with a large memory window

    International Nuclear Information System (INIS)

    Meng, Jianling; Yang, Rong; Zhao, Jing; He, Congli; Wang, Guole; Shi, Dongxia; Zhang, Guangyu

    2015-01-01

    Nanographene is a promising alternative to metal nanoparticles or semiconductor nanocrystals for charge trapping memory. In general, a high density of nanographene is required in order to achieve high charge trapping capacity. Here, we demonstrate a strategy of fabrication for a high density of nanographene for charge trapping memory with a large memory window. The fabrication includes two steps: (1) direct growth of continuous nanographene film; and (2) isolation of the as-grown film into high-density nanographene by plasma etching. Compared with directly grown isolated nanographene islands, abundant defects and edges are formed in nanographene under argon or oxygen plasma etching, i.e. more isolated nanographene islands are obtained, which provides more charge trapping sites. As-fabricated nanographene charge trapping memory shows outstanding memory properties with a memory window as wide as ∼9 V at a relative low sweep voltage of ±8 V, program/erase speed of ∼1 ms and robust endurance of >1000 cycles. The high-density nanographene charge trapping memory provides an outstanding alternative for downscaling technology beyond the current flash memory. (paper)

  6. Memory control with selective retention

    NARCIS (Netherlands)

    2012-01-01

    The present invention relates to a memory circuit and a method of controlling data retention in the memory circuit, wherein a supply signal is selectively switched to a respective one of at least two virtual supply lines (24) each shared by a respective one of a plurality of groups (30-1 to 30-n) of

  7. Memory control with selective retention

    NARCIS (Netherlands)

    2010-01-01

    The present invention relates to a memory circuit and a method of controlling data retention in the memory circuit, wherein a supply signal is selectively switched to a respective one of at least two virtual supply lines (24) each shared by a respective one of a plurality of groups (30-1 to 30-n) of

  8. Memory states in small arrays of Josephson junctions

    Energy Technology Data Exchange (ETDEWEB)

    Braiman, Yehuda [ORNLOak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computer Science and Mathematics Division, Computing and Computational Science Directorate; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Mechanical, Aerospace, and Biomedical Engineering; Neschke, Brendan [ORNLOak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computer Science and Mathematics Division, Computing and Computational Science Directorate; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Mechanical, Aerospace, and Biomedical Engineering; Nair, Niketh S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computer Science and Mathematics Division, Computing and Computational Science Directorate; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Mechanical, Aerospace, and Biomedical Engineering; Imam, Neena [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computing and Computational Science Directorat; Glowinski, R. [Univ. of Houston, TX (United States). Dept. of Mathematics

    2017-11-30

    Here, we study memory states of a circuit consisting of a small inductively coupled Josephson junction array and introduce basic (write, read, and reset) memory operations logics of the circuit. The presented memory operation paradigm is fundamentally different from conventional single quantum flux operation logics. We calculate stability diagrams of the zero-voltage states and outline memory states of the circuit. We also calculate access times and access energies for basic memory operations.

  9. Kaon Condensation in Neutron Stars and High Density Behaviour of Nuclear Symmetry Energy

    International Nuclear Information System (INIS)

    Kubis, S.; Kutschera, M.

    1999-01-01

    We study the influence of a high density behaviour of the nuclear symmetry energy on a kaon condensation in neutron stars. We find that the symmetry energy typical for several realistic nuclear potentials, which decreases at high densities, inhibits kaon condensation for weaker kaon-nucleon couplings at any density. There exists a threshold coupling above which the kaon condensate forms at densities exceeding some critical value. This is in contrast to the case of rising symmetry energy, as e.g. for relativistic mean field models, when the kaon condensate can form for any coupling at a sufficiently high density. Properties of the condensate are also different in both cases. (author)

  10. Kaon Condensation in Neutron Stars and High Density Behaviour of Nuclear Symmetry Energy

    International Nuclear Information System (INIS)

    Kubis, S.; Kutschera, M.

    1999-04-01

    We study the influence of a high density behaviour of the nuclear symmetry energy on a kaon condensation in neutron stars. We find that the symmetry energy typical for several realistic nuclear potentials, which decreases at high densities, inhibits kaon condensation for weaker kaon-nucleon couplings at any density. There exists a threshold coupling above which the kaon condensate forms at densities exceeding some critical value. This is in contrast to the case of rising symmetry energy, as e.g. for relativistic mean field models, when the kaon condensate can form for any coupling at a sufficiently high density. Properties of the condensate are also different in both cases

  11. Improvements in gastric diagnosis by using high density contrast media with low viscosity

    International Nuclear Information System (INIS)

    Toischer, H.P.

    1983-01-01

    In a retrospective clinical study, 150 unselected double contrast examinations of the stomach using conventional contrast media (100 g/100 ml barium sulphate) were compared with a similar number of examinations using a high density contrast medium of flow viscosity (250 g/100 ml barium sulphate). The high density contrast medium was distinctly better for demonstrating detail of the gastric mucosa. The uneveness of coating and instability of the older high density contrast media was observed in 15.5% of cases and, in no instance, did this make it impossible to reach a diagnosis. (orig.) [de

  12. The high density and high βpol disruption mechanism on TFTR

    International Nuclear Information System (INIS)

    Fredrickson, E.D.; Manickam, J.; McGuire, K.M.; Monticello, D.; Nagayama, Y.; Park, W.; Taylor, G.

    1992-01-01

    Studies of disruptions on TFTR have been extended to include high density disruptions as well as the high β pol disruptions. The data strongly suggests that the (m,n)=(1,1) mode plays an important role in both types of disruptions. Further, for the first time, it is unambiguously shown, using a fast electron cyclotron emission (ECE) instrument for the electron temperature profile measurements, that the (m,n)=(1,1) precursor to the high density disruptions has a 'cold bubble' structure. The precursor to the major disruption at high density resembles the 'vacuum bubble' model of disruptions first proposed by Kadomtsev and Pogutse. (author) 2 refs., 2 figs

  13. The endocrine-brain-aging triad where many paths meet: female reproductive hormone changes at midlife and their influence on circuits important for learning and memory.

    Science.gov (United States)

    Koebele, Stephanie V; Bimonte-Nelson, Heather A

    2017-08-01

    Female mammals undergo natural fluctuations in sex steroid hormone levels throughout life. These fluctuations span from early development, to cyclic changes associated with the menstrual or estrous cycle and pregnancy, to marked hormone flux during perimenopause, and a final decline at reproductive senescence. While the transition to reproductive senescence is not yet fully understood, the vast majority of mammals experience this spontaneous, natural phenomenon with age, which has broad implications for long-lived species. Indeed, this post-reproductive life stage, and its transition, involves significant and enduring physiological changes, including considerably altered sex steroid hormone and gonadotropin profiles that impact multiple body systems, including the brain. The endocrine-brain-aging triad is especially noteworthy, as many paths meet and interact. Many of the brain regions affected by aging are also sensitive to changes in ovarian hormone levels, and aging and reproductive senescence are both associated with changes in memory performance. This review explores how menopause is related to cognitive aging, and discusses some of the key neural systems and molecular factors altered with age and reproductive hormone level changes, with an emphasis on brain regions important for learning and memory. Copyright © 2017. Published by Elsevier Inc.

  14. Perovskites: Is the ultimate memory in sight?

    Science.gov (United States)

    Kingon, Angus

    2006-04-01

    With silicon microelectronics approaching fundamental limits, new concepts for high-density memory devices are sought. The individual switching of dislocations in oxides may offer just the right alternative.

  15. LOGIC CIRCUIT

    Science.gov (United States)

    Strong, G.H.; Faught, M.L.

    1963-12-24

    A device for safety rod counting in a nuclear reactor is described. A Wheatstone bridge circuit is adapted to prevent de-energizing the hopper coils of a ball backup system if safety rods, sufficient in total control effect, properly enter the reactor core to effect shut down. A plurality of resistances form one arm of the bridge, each resistance being associated with a particular safety rod and weighted in value according to the control effect of the particular safety rod. Switching means are used to switch each of the resistances in and out of the bridge circuit responsive to the presence of a particular safety rod in its effective position in the reactor core and responsive to the attainment of a predetermined velocity by a particular safety rod enroute to its effective position. The bridge is unbalanced in one direction during normal reactor operation prior to the generation of a scram signal and the switching means and resistances are adapted to unbalance the bridge in the opposite direction if the safety rods produce a predetermined amount of control effect in response to the scram signal. The bridge unbalance reversal is then utilized to prevent the actuation of the ball backup system, or, conversely, a failure of the safety rods to produce the predetermined effect produces no unbalance reversal and the ball backup system is actuated. (AEC)

  16. Atomic memory access hardware implementations

    Science.gov (United States)

    Ahn, Jung Ho; Erez, Mattan; Dally, William J

    2015-02-17

    Atomic memory access requests are handled using a variety of systems and methods. According to one example method, a data-processing circuit having an address-request generator that issues requests to a common memory implements a method of processing the requests using a memory-access intervention circuit coupled between the generator and the common memory. The method identifies a current atomic-memory access request from a plurality of memory access requests. A data set is stored that corresponds to the current atomic-memory access request in a data storage circuit within the intervention circuit. It is determined whether the current atomic-memory access request corresponds to at least one previously-stored atomic-memory access request. In response to determining correspondence, the current request is implemented by retrieving data from the common memory. The data is modified in response to the current request and at least one other access request in the memory-access intervention circuit.

  17. Assessing the functional properties of high-density lipoproteins : an emerging concept in cardiovascular research

    NARCIS (Netherlands)

    Triolo, Michela; Annema, Wijtske; Dullaart, Robin P. F.; Tietge, Uwe J. F.

    Although plasma concentrations of high-density lipoprotein (HDL) cholesterol correlate inversely with the incidence of atherosclerotic cardiovascular disease, results from recent epidemiological, genetic and pharmacological intervention studies resulted in a shift of concept. Rather than HDL

  18. Human plasma phospholipid transfer protein increases the antiatherogenic potential of high density lipoproteins in transgenic mice

    NARCIS (Netherlands)

    M.J. van Haperen (Rien); A. van Tol (Arie); P. Vermeulen; M. Jauhiainen; T. van Gent (Teus); P.M. van den Berg (Paul); S. Ehnholm (Sonja); A.W.M. van der Kamp (Arthur); M.P.G. de Crom (Rini); F.G. Grosveld (Frank)

    2000-01-01

    textabstractPlasma phospholipid transfer protein (PLTP) transfers phospholipids between lipoprotein particles and alters high density lipoprotein (HDL) subfraction patterns in vitro, but its physiological function is poorly understood. Transgenic mice that overexpress

  19. High-density lipoproteins and adrenal steroidogenesis : A population-based study

    NARCIS (Netherlands)

    Buitenwerf, Edward; Kerstens, Michiel N.; Links, Thera P.; Kema, Ido P.; Dullaart, Robin P. F.

    BACKGROUND: Cholesterol trafficked within plasma lipoproteins, in particular high-density lipoproteins (HDL), may represent an important source of cholesterol that is required for adrenal steroidogenesis. Based on a urinary gas chromatography method, compromised adrenal function has been suggested

  20. Moderate doses of alcoholic beverages with dinner and postprandial high density lipoprotein composition

    NARCIS (Netherlands)

    Hendriks, H.F.J.; Veenstra, J.; Tol, A. van; Groener, J.E.M.; Schaafsma, G.

    1998-01-01

    Moderate alcohol consumption is associated with a reduced risk of coronary heart disease. In this study, postprandial changes in plasma lipids, high-density lipoprotein (HDL) composition and cholesteryl ester transfer protein (CETP) and lecithin: cholesterol acyltransferase (LCAT) activity levels

  1. Short- circuit tests of circuit breakers

    OpenAIRE

    Chorovský, P.

    2015-01-01

    This paper deals with short-circuit tests of low voltage electrical devices. In the first part of this paper, there are described basic types of short- circuit tests and their principles. Direct and indirect (synthetic) tests with more details are described in the second part. Each test and principles are explained separately. Oscilogram is obtained from short-circuit tests of circuit breakers at laboratory. The aim of this research work is to propose a test circuit for performing indirect test.

  2. The memory effect of a pentacene field-effect transistor with a polarizable gate dielectric

    Science.gov (United States)

    Unni, K. N. N.; de Bettignies, Remi; Dabos-Seignon, Sylvie; Nunzi, Jean-Michel

    2004-06-01

    The nonvolatile transistor memory element is an interesting topic in organic electronics. In this case a memory cell consists of only one device where the stored information is written as a gate insulator polarization by a gate voltage pulse and read by the channel conductance control with channel voltage pulse without destruction of the stored information. Therefore such transistor could be the base of non-volatile non-destructively readable computer memory of extremely high density. Also devices with polarizable gate dielectrics can function more effectively in certain circuits. The effective threshold voltage Vt can be brought very close to zero, for applications where the available gate voltage is limited. Resonant and adaptive circuits can be tuned insitu by polarizing the gates. Poly(vinylidene fluoride), PVDF and its copolymer with trifluoroethylene P(VDF-TrFE) are among the best known and most widely used ferroelectric polymers. In this manuscript, we report new results of an organic FET, fabricated with pentacene as the active material and P(VDF-TrFE) as the gate insulator. Application of a writing voltage of -50 V for short duration results in significant change in the threshold voltage and remarkable increase in the drain current. The memory effect is retained over a period of 20 hours.

  3. Twin-bit via resistive random access memory in 16 nm FinFET logic technologies

    Science.gov (United States)

    Shih, Yi-Hong; Hsu, Meng-Yin; King, Ya-Chin; Lin, Chrong Jung

    2018-04-01

    A via resistive random access memory (RRAM) cell fully compatible with the standard CMOS logic process has been successfully demonstrated for high-density logic nonvolatile memory (NVM) modules in advanced FinFET circuits. In this new cell, the transition metal layers are formed on both sides of a via, given two storage bits per via. In addition to its compact cell area (1T + 14 nm × 32 nm), the twin-bit via RRAM cell features a low operation voltage, a large read window, good data retention, and excellent cycling capability. As fine alignments between mask layers become possible, the twin-bit via RRAM cell is expected to be highly scalable in advanced FinFET technology.

  4. High-density polymer microarrays: identifying synthetic polymers that control human embryonic stem cell growth.

    Science.gov (United States)

    Hansen, Anne; Mjoseng, Heidi K; Zhang, Rong; Kalloudis, Michail; Koutsos, Vasileios; de Sousa, Paul A; Bradley, Mark

    2014-06-01

    The fabrication of high-density polymer microarray is described, allowing the simultaneous and efficient evaluation of more than 7000 different polymers in a single-cellular-based screen. These high-density polymer arrays are applied in the search for synthetic substrates for hESCs culture. Up-scaling of the identified hit polymers enables long-term cellular cultivation and promoted successful stem-cell maintenance. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. CMOS integration of high-k/metal gate transistors in diffusion and gate replacement (D&GR) scheme for dynamic random access memory peripheral circuits

    Science.gov (United States)

    Dentoni Litta, Eugenio; Ritzenthaler, Romain; Schram, Tom; Spessot, Alessio; O’Sullivan, Barry; Machkaoutsan, Vladimir; Fazan, Pierre; Ji, Yunhyuck; Mannaert, Geert; Lorant, Christophe; Sebaai, Farid; Thiam, Arame; Ercken, Monique; Demuynck, Steven; Horiguchi, Naoto

    2018-04-01

    Integration of high-k/metal gate stacks in peripheral transistors is a major candidate to ensure continued scaling of dynamic random access memory (DRAM) technology. In this paper, the CMOS integration of diffusion and gate replacement (D&GR) high-k/metal gate stacks is investigated, evaluating four different approaches for the critical patterning step of removing the N-type field effect transistor (NFET) effective work function (eWF) shifter stack from the P-type field effect transistor (PFET) area. The effect of plasma exposure during the patterning step is investigated in detail and found to have a strong impact on threshold voltage tunability. A CMOS integration scheme based on an experimental wet-compatible photoresist is developed and the fulfillment of the main device metrics [equivalent oxide thickness (EOT), eWF, gate leakage current density, on/off currents, short channel control] is demonstrated.

  6. Collective of mechatronics circuit

    International Nuclear Information System (INIS)

    1987-02-01

    This book is composed of three parts, which deals with mechatronics system about sensor, circuit and motor. The contents of the first part are photo sensor of collector for output, locating detection circuit with photo interrupts, photo sensor circuit with CdS cell and lamp, interface circuit with logic and LED and temperature sensor circuit. The second part deals with oscillation circuit with crystal, C-R oscillation circuit, F-V converter, timer circuit, stability power circuit, DC amp and DC-DC converter. The last part is comprised of bridge server circuit, deformation bridge server, controlling circuit of DC motor, controlling circuit with IC for PLL and driver circuit of stepping motor and driver circuit of Brushless.

  7. Collective of mechatronics circuit

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-02-15

    This book is composed of three parts, which deals with mechatronics system about sensor, circuit and motor. The contents of the first part are photo sensor of collector for output, locating detection circuit with photo interrupts, photo sensor circuit with CdS cell and lamp, interface circuit with logic and LED and temperature sensor circuit. The second part deals with oscillation circuit with crystal, C-R oscillation circuit, F-V converter, timer circuit, stability power circuit, DC amp and DC-DC converter. The last part is comprised of bridge server circuit, deformation bridge server, controlling circuit of DC motor, controlling circuit with IC for PLL and driver circuit of stepping motor and driver circuit of Brushless.

  8. Evaluating Approaches to Rendering Braille Text on a High-Density Pin Display.

    Science.gov (United States)

    Morash, Valerie S; Russomanno, Alexander; Gillespie, R Brent; OModhrain, Sile

    2017-10-13

    Refreshable displays for tactile graphics are typically composed of pins that have smaller diameters and spacing than standard braille dots. We investigated configurations of high-density pins to form braille text on such displays using non-refreshable stimuli produced with a 3D printer. Normal dot braille (diameter 1.5 mm) was compared to high-density dot braille (diameter 0.75 mm) wherein each normal dot was rendered by high-density simulated pins alone or in a cluster of pins configured in a diamond, X, or square; and to "blobs" that could result from covering normal braille and high-density multi-pin configurations with a thin membrane. Twelve blind participants read MNREAD sentences displayed in these conditions. For high-density simulated pins, single pins were as quickly and easily read as normal braille, but diamond, X, and square multi-pin configurations were slower and/or harder to read than normal braille. We therefore conclude that as long as center-to-center dot spacing and dot placement is maintained, the dot diameter may be open to variability for rendering braille on a high density tactile display.

  9. Clinical significance of diminution of high-density areas in basal cisterns following acute aneurysmal bleeding

    International Nuclear Information System (INIS)

    Matsuzaki, Takayuki; Takeda, Rihei; Nakagawara, Jyoji; Sato, Shigeru; Fujiwara, Hidetoshi

    1983-01-01

    We analyzed the sequential changes in the high density in basal cisterns in the acute stage of aneurysmal bleeding. We could recognize Group 3 (clot or thick layer), according to Fisher's classification, in 66.3% of the intracranial aneurysms at admission (83 cases). In the early stage of an intracranial aneurysm, a subarachnoid hemorrhage (SAH) was detected in all the patients on CT. We evaluated 40 cases of Group 3 sequentially on CT. This investigation showed that 55% of the Grade I--Ii group, 27.3% of the Grade III group, and 11.1% of the Grade IV--V group changed to Group 2(thin or diffuse pattern) in approximately 20 hours on the average. As for the correlation between the high density in basal cisterns and the neurological condition (Hunt and Hess), we found a neurological improvement in the decreased-high-density group. The unchanged- high-density group showed deterioration. Compared with the decreased-high-density group, the unchanged group showed a greater increase in the CVI (Cerebro Ventricular Index). RI ( 111 In) cisternography also showed a disturbance of the CSF circulation. To lower the vasospasm it is important to decrease the high density in an early stage by carrying out CSF. It was considered to be prognostic when a CT scan was performed within 24 hours after SAH. (author)

  10. Potential formation and confinement in high density plasma on the GAMMA 10 tandem mirror

    International Nuclear Information System (INIS)

    Yatsu, K.

    2002-01-01

    After the attainment of doubling of the density due to the potential confinement, GAMMA 10 experiments have been directed to realization of a high density plasma and also to study dependence of the confining potential and confinement time on the plasma density. These problems are important to understand the physics of potential formation in tandem mirrors and also for the development of a tandem mirror reactor. We reported high density plasma production by using an ion cyclotron range of frequency heating at a high harmonic frequency in the last IAEA Conference. However, the diamagnetic signal of the high density plasma decreased when electron cyclotron resonance heating (ECRH) was applied due to some instabilities. Recently, the high density plasma production was much improved by adjusting the spacing of the conducting plates installed in the anchor transition regions, which enabled us to produce a high density plasma without degradation of the diamagnetic signal with ECRH and also to study the density dependence. In this paper we report production of a high density plasma and dependence of the confining potential and the confinement time on the density. (author)

  11. Circuit parties.

    Science.gov (United States)

    Guzman, R

    2000-03-01

    Circuit parties are extended celebrations, lasting from a day to a week, primarily attended by gay and bisexual men in their thirties and forties. These large-scale dance parties move from city to city and draw thousands of participants. The risks for contracting HIV during these parties include recreational drug use and unsafe sex. Limited data exists on the level of risk at these parties, and participants are skeptical of outside help because of past criticism of these events. Health care and HIV advocates can promote risk-reduction strategies with the cooperation of party planners and can counsel individuals to personally reduce their own risk. To convey the message, HIV prevention workers should emphasize positive and community-centered aspects of the parties, such as taking care of friends and avoiding overdose.

  12. High-bandwidth memory interface

    CERN Document Server

    Kim, Chulwoo; Song, Junyoung

    2014-01-01

    This book provides an overview of recent advances in memory interface design at both the architecture and circuit levels. Coverage includes signal integrity and testing, TSV interface, high-speed serial interface including equalization, ODT, pre-emphasis, wide I/O interface including crosstalk, skew cancellation, and clock generation and distribution. Trends for further bandwidth enhancement are also covered.   • Enables readers with minimal background in memory design to understand the basics of high-bandwidth memory interface design; • Presents state-of-the-art techniques for memory interface design; • Covers memory interface design at both the circuit level and system architecture level.

  13. Commutation circuit for an HVDC circuit breaker

    Science.gov (United States)

    Premerlani, William J.

    1981-01-01

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components.

  14. Liver lipase and high-density lipoprotein. Lipoprotein changes after incubation of human serum with rat liver lipase.

    Science.gov (United States)

    Groot, P H; Scheek, L M; Jansen, H

    1983-05-16

    Human sera were incubated with rat liver lipase after inactivation of lecithin:cholesterol acyltransferase, and the changes in serum lipoprotein composition were measured. In the presence of liver lipase serum triacylglycerol and phosphatidylcholine were hydrolyzed. The main changes in the concentrations of these lipids were found in the high-density lipoprotein fraction. Subfractionation of high-density lipoprotein by rate-zonal ultracentrifugation showed a prominent decrease in all constituents of high-density lipoprotein2, a smaller decrease in the 'light' high-density lipoprotein3 and an increase in the 'heavy' high-density lipoprotein3. These data support a concept in which liver lipase is involved in high-density lipoprotein2 phospholipid and triacylglycerol catabolism and suggest that as a result of this action high-density lipoprotein2 is converted into high-density lipoprotein3.

  15. Analog circuit design designing dynamic circuit response

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    This second volume, Designing Dynamic Circuit Response builds upon the first volume Designing Amplifier Circuits by extending coverage to include reactances and their time- and frequency-related behavioral consequences.

  16. Trigger circuit

    International Nuclear Information System (INIS)

    Verity, P.R.; Chaplain, M.D.; Turner, G.D.J.

    1984-01-01

    A monostable trigger circuit comprises transistors TR2 and TR3 arranged with their collectors and bases interconnected. The collector of the transistor TR2 is connected to the base of transistor TR3 via a capacitor C2 the main current path of a grounded base transistor TR1 and resistive means R2,R3. The collector of transistor TR3 is connected to the base of transistor TR2 via resistive means R6, R7. In the stable state all the transistors are OFF, the capacitor C2 is charged, and the output is LOW. A positive pulse input to the base of TR2 switches it ON, which in turn lowers the voltage at points A and B and so switches TR1 ON so that C2 can discharge via R2, R3, which in turn switches TR3 ON making the output high. Thus all three transistors are latched ON. When C2 has discharged sufficiently TR1 switches OFF, followed by TR3 (making the output low again) and TR2. The components C1, C3 and R4 serve to reduce noise, and the diode D1 is optional. (author)

  17. An optoelectronic integrated device including a laser and its driving circuit

    Energy Technology Data Exchange (ETDEWEB)

    Matsueda, H.; Nakano, H.; Tanaka, T.P.

    1984-10-01

    A monolithic optoelectronic integrated circuit (OEIC) including a laser diode, photomonitor and driving and detecting circuits has been fabricated on a semi-insulating GaAs substrate. The OEIC has a horizontal integrating structure which is suitable for realising high-density multifunctional devices. The fabricating process and the static and dynamic characteristics of the optical and electronic elements are described. The preliminary results of the co-operative operation of the laser and its driving circuit are also presented.

  18. A novel method for the fabrication of a high-density carbon nanotube microelectrode array

    Directory of Open Access Journals (Sweden)

    Adam Khalifa

    2015-09-01

    Full Text Available We present a novel method for fabricating a high-density carbon nanotube microelectrode array (MEA chip. Vertically aligned carbon nanotubes (VACNTs were synthesized by microwave plasma-enhanced chemical vapor deposition and thermal chemical vapor deposition. The device was characterized using electrochemical experiments such as cyclic voltammetry, impedance spectroscopy and potential transient measurements. Through-silicon vias (TSVs were fabricated and partially filled with polycrystalline silicon to allow electrical connection from the high-density electrodes to a stimulator microchip. In response to the demand for higher resolution implants, we have developed a unique process to obtain a high-density electrode array by making the microelectrodes smaller in size and designing new ways of routing the electrodes to current sources. Keywords: Microelectrode array, Neural implant, Carbon nanotubes, Through-silicon via interconnects, Microfabrication

  19. Insights on consciousness from taste memory research.

    Science.gov (United States)

    Gallo, Milagros

    2016-01-01

    Taste research in rodents supports the relevance of memory in order to determine the content of consciousness by modifying both taste perception and later action. Associated with this issue is the fact that taste and visual modalities share anatomical circuits traditionally related to conscious memory. This challenges the view of taste memory as a type of non-declarative unconscious memory.

  20. High-Density Chemical Intercalation of Zero-Valent Copper into Bi 2 Se 3 Nanoribbons

    KAUST Repository

    Koski, Kristie J.; Cha, Judy J.; Reed, Bryan W.; Wessells, Colin D.; Kong, Desheng; Cui, Yi

    2012-01-01

    A major goal of intercalation chemistry is to intercalate high densities of guest species without disrupting the host lattice. Many intercalant concentrations, however, are limited by the charge of the guest species. Here we have developed a general solution-based chemical method for intercalating extraordinarily high densities of zero-valent copper metal into layered Bi 2Se 3 nanoribbons. Up to 60 atom % copper (Cu 7.5Bi 2Se 3) can be intercalated with no disruption to the host lattice using a solution disproportionation redox reaction. © 2012 American Chemical Society.

  1. Reprocessing ability of high density fuels for research and test reactors

    International Nuclear Information System (INIS)

    Gay, A.; Belieres, M.

    1997-01-01

    The development of a new high density fuel is becoming a key issue for Research Reactors operators. Such a new fuel should be a Low Enrichment Uranium (LEU) fuel with a high density, to improve present in core performances. It must be compatible with the reprocessing in an industrial plant to provide a steady back-end solution. Within the framework of a work group CEA/CERCA/COGEMA on new fuel development for Research Reactors, COGEMA has performed an evaluation of the reprocessing ability of some fuel dispersants selected as good candidates. The results will allow US to classify these fuel dispersants from a reprocessing ability point of view. (author)

  2. Slow crack growth in post-consumer recycled high-density polyethylene

    OpenAIRE

    Sciammarella, Cesar A.; Yang, Y.

    2015-01-01

    An experimental study of slow crack growth behavior of post-consumer recycled high-density polyethylene blended with virgin high-density polyethylene copolymer has been done. The study has been performed under constant load and in baths of distilled water at 40, 60, 80°C. The specimen used is notched with side grooves. The test results of crack growth have been analyzed using linear fracture mechanics and the rate process theory. The results show that the resistance to crack growth increases ...

  3. High-Density Chemical Intercalation of Zero-Valent Copper into Bi 2 Se 3 Nanoribbons

    KAUST Repository

    Koski, Kristie J.

    2012-05-09

    A major goal of intercalation chemistry is to intercalate high densities of guest species without disrupting the host lattice. Many intercalant concentrations, however, are limited by the charge of the guest species. Here we have developed a general solution-based chemical method for intercalating extraordinarily high densities of zero-valent copper metal into layered Bi 2Se 3 nanoribbons. Up to 60 atom % copper (Cu 7.5Bi 2Se 3) can be intercalated with no disruption to the host lattice using a solution disproportionation redox reaction. © 2012 American Chemical Society.

  4. Properties of high-density matter in the electroweak symmetric phase

    International Nuclear Information System (INIS)

    Chandra, D.; Goyal, A.

    1992-01-01

    We examine the bulk properties of matter at high densities and finite temperatures in the phase where electroweak symmetry is exact and fermions are massless, by taking the strong interactions into account perturbatively to lowest order in the quark-gluon chromodynamic coupling constant α c . We also discuss the possibility of a phase transition of strange quark matter into this high-density matter in the electroweak symmetric phase at densities likely to be present in the core of dense neutron stars or collapsing stars. Finally, we study the properties of finite-size chunks of this matter by taking surface effects into account and give an estimate of the surface tension

  5. Stochastic memory: getting memory out of noise

    Science.gov (United States)

    Stotland, Alexander; di Ventra, Massimiliano

    2011-03-01

    Memory circuit elements, namely memristors, memcapacitors and meminductors, can store information without the need of a power source. These systems are generally defined in terms of deterministic equations of motion for the state variables that are responsible for memory. However, in real systems noise sources can never be eliminated completely. One would then expect noise to be detrimental for memory. Here, we show that under specific conditions on the noise intensity memory can actually be enhanced. We illustrate this phenomenon using a physical model of a memristor in which the addition of white noise into the state variable equation improves the memory and helps the operation of the system. We discuss under which conditions this effect can be realized experimentally, discuss its implications on existing memory systems discussed in the literature, and also analyze the effects of colored noise. Work supported in part by NSF.

  6. A large dynamic range radiation-tolerant analog memory in a quarter- micron CMOS technology

    CERN Document Server

    Anelli, G; Rivetti, A

    2001-01-01

    An analog memory prototype containing 8*128 cells has been designed in a commercial quarter-micron CMOS process. The aim of this work is to investigate the possibility of designing large dynamic range mixed-mode switched capacitor circuits for high-energy physics (HEP) applications in deep submicron CMOS technologies. Special layout techniques have been used to make the circuit radiation tolerant. The memory cells employ gate-oxide capacitors for storage, permitting a very high density. A voltage write-voltage read architecture has been chosen to minimize the sensitivity to absolute capacitor values. The measured input voltage range is 2.3 V (the power supply voltage V/sub DD/ is equal to 2.5 V), with a linearity of almost 8 bits over 2 V. The dynamic range is more than 11 bits. The pedestal variation is +or-0.5 mV peak-to-peak. The noise measured, which is dominated by the noise of the measurement setup, is around 0.8 mV rms. The characteristics of the memory have been measured before irradiation and after 1...

  7. A large dynamic range radiation tolerant analog memory in a quarter micron CMOS technology

    CERN Document Server

    Anelli, G; Rivetti, A

    2000-01-01

    A 8*128 cell analog memory prototype has been designed in a commercial 0.25 jam CMOS process. The aim of this work was to investigate the possibility of designing large dynamic range mixed- mode switched capacitor circuits for High-Energy Physics (HEP) applications in deep submicron CMOS technologies. Special layout techniques have been used to make the circuit radiation tolerant left bracket 1 right bracket . The memory cells employ gate-oxide capacitors for storage, allowing for a very high density. A voltage write - voltage read architecture has been chosen to minimize the sensitivity to absolute capacitor values. The measured input voltage range is 2.3 V (V//D//D = 2.5 V), with a linearity of at least 7.5 bits over 2 V. The dynamic range is more than 11 bits. The pedestal variation is plus or minus 0.5 mV peak-to-peak. The noise measured, which is dominated by the noise of the measurement setup, is around 0.8 mV rms. The characteristics of the memory have been measured before irradiation and after lOMrd (...

  8. Controlled data storage for non-volatile memory cells embedded in nano magnetic logic

    Directory of Open Access Journals (Sweden)

    Fabrizio Riente

    2017-05-01

    Full Text Available Among the beyond-CMOS technologies, perpendicular Nano Magnetic Logic (pNML is a promising candidate due to its low power consumption, its non-volatility and its monolithic 3D integrability, which makes it possible to integrate memory and logic into the same device by exploiting the interaction of bi-stable nanomagnets with perpendicular magnetic anisotropy. Logic computation and signal synchronization are achieved by focus ion beam irradiation and by pinning domain walls in magnetic notches. However, in realistic circuits, the information storage and their read-out are crucial issues, often ignored in the exploration of beyond-CMOS devices. In this paper we address these issues by experimentally demonstrating a pNML memory element, whose read and write operations can be controlled by two independent pulsed currents. Our results prove the correct behavior of the proposed structure that enables high density memory embedded in the logic plane of 3D-integrated pNML circuits.

  9. Magnetic force microscopy of thin film media for high density magnetic recording

    NARCIS (Netherlands)

    Porthun, Steffen; Porthun, S.; Abelmann, Leon; Lodder, J.C.

    1998-01-01

    This paper discusses various aspect of magnetic force microscopy (MFM) for use in the field of high density magnetic recording. After an introduction of the most important magnetic imaging techniques, an overview is given of the operation and theory of MFM. The developments in instrumentation, MFM

  10. A case of thalamic hemorrhage presenting high density on CT in a long time

    International Nuclear Information System (INIS)

    Hosoya, Takaaki; Takeda, Yoshio; Sugai, Yukio; Umetsu, Akemi; Yamaguchi, Koichi

    1988-01-01

    We presented a thalamic hemorrhage in a 29-year-old woman with idiopathic thrombocytopenic purpura during pregnancy showing a high density lesion at least for 50 days on CT. From beginning of the illness, this condition was considered to continue for 3 months by chronic bleeding or recurrent hemorrhage. (author)

  11. Genetic analysis of long-lived families reveals novel variants influencing high density-lipoprotein cholesterol

    DEFF Research Database (Denmark)

    Feitosa, Mary F; Wojczynski, Mary K; Straka, Robert

    2014-01-01

    The plasma levels of high-density lipoprotein cholesterol (HDL) have an inverse relationship to the risks of atherosclerosis and cardiovascular disease (CVD), and have also been associated with longevity. We sought to identify novel loci for HDL that could potentially provide new insights...

  12. Electrical and mechanical properties of highly elongated high density polyethylene as cryogenic insulation materials

    International Nuclear Information System (INIS)

    Yoshino, Katsumi; Park, Dae-Hee; Miyata, Kiyomi; Yamaoka, Hitoshi; Itoh, Minoru; Ichihara, Syouji.

    1989-01-01

    Electrical and mechanical properties of highly elongated high density polyethylene were investigated in the temperature range between 4.2 K and 400 K from a viewpoint of electrical insulation at low temperature and the following properties have been clarified. (1) The electrical conductivity of samples decreases with increasing draw ratio, and also decreases at cryogenic temperature. (2) Breakdown strength of highly elongated sample is similar to that of non-elongated sample. It is nearby temperature independent below 300 K but at higher temperature it falls steeply. (3) Mechanical breakdown stress and elastic modulus of high density polyethylene increase with increasing draw ratio. Their values at liquid nitrogen temperature are much higher than that at room temperature. On the other hand, strains decreases at liquid nitrogen temperature. (4) Break of the sample develops in the direction of 45deg from the direction of stress both at room temperature and at cryogenic temperature. (5) The characteristic of mechanical breakdown at liquid nitrogen temperature can be explained by a brittleness fracture process. (6) Toughness of high density polyethylene increases with increasing draw ratio until draw ratio of 5, and it decreased, and increase at higher draw ratio. However at extremely high draw ratio of 10 it again increases. These findings clearly indicate that highly elongated high density polyethylene has good electrical and mechanical properties at cryogenic temperature and can be used as the insulating materials at cryogenic temperature. (author)

  13. Residual gas entering high density hydrogen plasma: rarefaction due to rapid heating

    NARCIS (Netherlands)

    N. den Harder,; D.C. Schram,; W. J. Goedheer,; de Blank, H. J.; M. C. M. van de Sanden,; van Rooij, G. J.

    2015-01-01

    The interaction of background molecular hydrogen with magnetized (0.4 T) high density (1–5 × 10 20  m −3 ) low temperature (∼3 eV) hydrogen plasma was inferred from the Fulcher band emission in the linear plasma generator Pilot-PSI. In the plasma center,

  14. Value of information to improve daily operations in high-density logistics

    NARCIS (Netherlands)

    Viet, Nguyen Quoc; Behdani, Behzad; Bloemhof, Jacqueline

    2018-01-01

    Agro-food logistics is increasingly challenged to ensure that a wide variety of high-quality products are always available at retail stores. This paper discusses high-density logistics issues caused by more frequent and smaller orders from retailers. Through a case study of the distribution process

  15. Turbulence at the transition to the high density H-mode in Wendelstein 7-AS plasmas

    DEFF Research Database (Denmark)

    Basse, N.P.; Zoletnik, S.; Baumel, S.

    2003-01-01

    Recently a new improved confinement regime was found in the Wendelstein 7-AS (W7-AS) stellarator (Renner H. et al 1989 Plasma Phys. Control. Fusion 31 1579). The discovery of this high density high confinement mode (HDH-mode) was facilitated by the installation of divertor modules. In this paper,...

  16. High-density EEG coherence analysis using functional units applied to mental fatigue

    NARCIS (Netherlands)

    Caat, Michael ten; Lorist, Monicque M.; Bezdan, Eniko; Roerdink, Jos B.T.M.; Maurits, Natasha M.

    2008-01-01

    Electroencephalography (EEG) coherence provides a quantitative measure of functional brain connectivity which is calculated between pairs of signals as a function of frequency. Without hypotheses, traditional coherence analysis would be cumbersome for high-density EEG which employs a large number of

  17. Usefulness of multi-plane dynamic subtraction CT (MPDS-CT) for intracranial high density lesions

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Ryo; Kumazaki, Tatsuo [Nippon Medical School, Tokyo (Japan)

    1996-02-01

    We present a new CT technique using the high speed CT scanner in detection and evaluation of temporal and spatial contrast enhancement of intracranial high density lesions. A multi-plane dynamic subtraction CT (MPDS-CT) was performed in 21 patients with intracranial high density lesions. These lesions consisted of 10 brain tumors, 7 intracerebral hemorrhages and 4 vascular malformations (2 untreated, 2 post-embolization). Baseline study was first performed, and 5 sequential planes of covering total high density lesions were selected. After obtaining the 5 sequential CT images as mask images, three series of multi-plane dynamic CT were performed for the same 5 planes with an intravenous bolus injection of contrast medium. MPDS-CT images were reconstructed by subtracting dynamic CT images from the mask ones. MPDS-CT were compared with conventional contrast-enhanced CT. MPDS-CT images showed the definite contrast enhancement of high density brain tumors and vascular malformations which were not clearly identified on conventional contrast-enhanced CT images because of calcified or hemorrhagic lesions and embolic materials, enabling us to eliminate enhanced abnormalities with non-enhanced areas such as unusual intracerebral hemorrhages. MPDS-CT will provide us further accurate and objective information and will be greatly helpful for interpreting pathophysiologic condition. (author).

  18. Should we change our lipid management strategies to focus on non-high-density lipoprotein cholesterol?

    NARCIS (Netherlands)

    Rana, Jamal S.; Boekholdt, S. Matthijs

    2010-01-01

    Purpose of review Despite aggressive low-density lipoprotein cholesterol lowering, patients continue to be at significant risk of cardiovascular events. Assessment of non-high-density lipoprotein cholesterol (non-HDL-C) provides a measure of cholesterol contained in all atherogenic particles. In the

  19. Application of Inkjet Printing in High-Density Pixelated RGB Quantum Dot-Hybrid LEDs

    KAUST Repository

    Haverinen, Hanna; Jabbour, Ghassan E.

    2012-01-01

    to fabricate high-density, pixelated (quarter video graphics array (QVGA) format), monochromatic and RGB quantum dots light-emitting diodes (QDLEDs), where inkjet printing is used to deposit the light-emitting layer of QDs. It shows some of the factors

  20. Los Alamos compact toroid, fast-liner, and high-density Z-pinch programs

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.K.; Sherwood, A.R.; Hammel, J.E.

    1981-03-01

    The Compact Toroid (CT) and High Density Z-Pinch (HDZP) are two of the plasma configurations presently being studied at Los Alamos. The purpose of these two programs, plus the recently terminated (May 1979) Fast Liner (FL) program, is summarized in this section along with a brief description of the experimental facilities. The remaining sections summarize the recent results and the experimental status.

  1. THE GRAFTING OF MALEIC-ANHYDRIDE ON HIGH-DENSITY POLYETHYLENE IN AN EXTRUDER

    NARCIS (Netherlands)

    GANZEVELD, KJ; JANSSEN, LPBM

    The grafting of maleic anhydride (MAH) on high density polyethylene in a counter-rotating twin screw extruder has been studied. As the reaction kinetics appear to be affected by mass transfer, good micro mixing in the extruder is important. Due to the competing mechanisms of increasing mixing and

  2. High-density lipoprotein modulates glucose metabolism in patients with type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Drew, Brian G; Duffy, Stephen J; Formosa, Melissa F

    2009-01-01

    BACKGROUND: Low plasma high-density lipoprotein (HDL) is associated with elevated cardiovascular risk and aspects of the metabolic syndrome. We hypothesized that HDL modulates glucose metabolism via elevation of plasma insulin and through activation of the key metabolic regulatory enzyme, AMP...

  3. Self-consistency condition and high-density virial theorem in relativistic many-particle systems

    International Nuclear Information System (INIS)

    Kalman, G.; Canuto, V.; Datta, B.

    1976-01-01

    In order for the thermodynamic and kinetic definitions of the chemical potential and the pressure to lead to identical results a nontrivial self-consistency criterion has to be satisfied. This, in turn, leads to a virial-like theorem in the high-density limit

  4. Scaling of energy confinement and poloidal beta in high density tokamaks

    NARCIS (Netherlands)

    Schram, D.C.; Schüller, F.C.

    1980-01-01

    A semi-empirical analysis of the heat balance of ohmically heated, high density Tokamak plasmas, shows that the observed heat transport can be explained by neoclassical (plateau) ion heat conduction in the central part of the plasma. Experimental values for Te, ß¿e, and tEe and the variation of

  5. Collision frequency of Lennard–Jones fluids at high densities by ...

    Indian Academy of Sciences (India)

    Detailed classical molecular dynamics simulation of transport coefficients and collision frequencies at high densities in rare gases are presented in this paper with a view to investigate the likely cause of discrepancy between theory and experiments. The results, when compared with experiments, showed an ...

  6. The biological properties of iron oxide core high-density lipoprotein in experimental atherosclerosis

    NARCIS (Netherlands)

    Skajaa, Torjus; Cormode, David P.; Jarzyna, Peter A.; Delshad, Amanda; Blachford, Courtney; Barazza, Alessandra; Fisher, Edward A.; Gordon, Ronald E.; Fayad, Zahi A.; Mulder, Willem J. M.

    2011-01-01

    Lipoproteins are a family of plasma nanoparticles responsible for the transportation of lipids throughout the body. High-density lipoprotein (HDL), the smallest of the lipoprotein family, measures 7-13 nm in diameter and consists of a cholesteryl ester and triglyceride core that is covered with a

  7. Nanocrystal core high-density lipoproteins: a multimodality contrast agent platform

    NARCIS (Netherlands)

    Cormode, David P.; Skajaa, Torjus; van Schooneveld, Matti M.; Koole, Rolf; Jarzyna, Peter; Lobatto, Mark E.; Calcagno, Claudia; Barazza, Alessandra; Gordon, Ronald E.; Zanzonico, Pat; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J. M.

    2008-01-01

    High density lipoprotein (HDL) is an important natural nanoparticle that may be modified for biomedical imaging purposes. Here we developed a novel technique to create unique multimodality HDL mimicking nanoparticles by incorporation of gold, iron oxide, or quantum dot nanocrystals for computed

  8. Identifying dielectric and resistive electrode losses in high-density capacitors at radio frequencies

    NARCIS (Netherlands)

    Tiggelman, M.P.J.; Reimann, K.; Liu, J.; Klee, M.; Keur, W.; Mauczock, R.; Schmitz, Jurriaan; Hueting, Raymond Josephus Engelbart

    2008-01-01

    A regression-based technique is presented which distinguishes the dielectric loss from the resistive loss of high density planar capacitors in a very wide bandwidth of 0.1–8 GHz. Moreover, the procedure yields useful results if the capacitor deviates from a lumped element model and indicates when

  9. Guidelines for etching silicon MEMS structures using fluorine high-density plasmas at cryogenic temperatures

    NARCIS (Netherlands)

    de Boer, Meint J.; Gardeniers, Johannes G.E.; Jansen, Henricus V.; Gilde, M.J.; Roelofs, Gerard; Sasserath, Jay N.; Elwenspoek, Michael Curt

    This paper presents guidelines for the deep reactive ion etching (DRIE) of silicon MEMS structures, employing SF6/O2-based high-density plasmas at cryogenic temperatures. Procedures of how to tune the equipment for optimal results with respect to etch rate and profile control are described. Profile

  10. Increased Antioxidant Quality Versus Lower Quantity Of High Density Lipoprotein In Benign Prostatic Hyperplasia

    Directory of Open Access Journals (Sweden)

    Aydin Ozgur

    2015-10-01

    Full Text Available Background: Oxidative stress may be involved in the pathogenesis of every human disease. To understand its possible role in benign prostatic hyperplasia (BPH, we measured the overall oxidative status of patients with BPH and the serum activity of the high density lipoprotein (HDL-related antioxidant enzymes paraoxonase 1 (PON1 and arylesterase (ARE.

  11. Neutron star models with realistic high-density equations of state

    International Nuclear Information System (INIS)

    Malone, R.C.; Johnson, M.B.; Bethe, H.A.

    1975-01-01

    We calculate neutron star models using four realistic high-density models of the equation of state. We conclude that the maximum mass of a neutron star is unlikely to exceed 2 M/sub sun/. All of the realistic models are consistent with current estimates of the moment of inertia of the Crab pulsar

  12. Amorphous silicon rich silicon nitride optical waveguides for high density integrated optics

    DEFF Research Database (Denmark)

    Philipp, Hugh T.; Andersen, Karin Nordström; Svendsen, Winnie Edith

    2004-01-01

    Amorphous silicon rich silicon nitride optical waveguides clad in silica are presented as a high-index contrast platform for high density integrated optics. Performance of different cross-sectional geometries have been measured and are presented with regards to bending loss and insertion loss...

  13. Structure and properties of simple molecular systems at very high density

    International Nuclear Information System (INIS)

    LeSar, R.

    1989-01-01

    The use of computer simulations in the study of molecular systems at very high density is reviewed. Applications to the thermodynamics of dense fluid nitrogen and phase transitions in solid oxygen are presented. The effects of changes in the atomic electronic structure on the equation of state of very dense helium are discussed. 19 refs., 2 figs

  14. Spin polarization in high density quark matter under a strong external magnetic field

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; Da Providência, João; Providência, Constança

    2016-01-01

    In high density quark matter under a strong external magnetic field, possible phases are investigated by using the two-flavor Nambu-Jona-Lasinio (NJL) model with tensor-type four-point interaction between quarks, as well as the axial-vector-type four-point interaction. In the tensor-type interact...

  15. Interplay between spin polarization and color superconductivity in high density quark matter

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; da Providência, João; Providência, Constança

    2013-01-01

    Here, it is suggested that a four-point interaction of the tensor type may lead to spin polarization in quark matter at high density. It is found that the two-flavor superconducting phase and the spin polarized phase correspond to distinct local minima of a certain generalized thermodynamical pot...

  16. Effect of resin variables on the creep behavior of high density hardwood composite panels

    Science.gov (United States)

    R.C. Tang; Jianhua Pu; C.Y Hse

    1993-01-01

    The flexural creep behavior of oriented strandboards (OSB) fabricated with mixed high, density hardwood flakes was investigated. Three types of adhesives, liquid phenolic-formaldehyde (LPF), melamine modified urea-formaldehyde (MUF), and LPF (face)/MUF (core) were chosen in this investigation. The resin contents (RC) used were 3.5 percent and 5.0 percent. The flakes...

  17. Production of an economic high-density concrete for shielding megavoltage radiotherapy rooms and nuclear reactors

    International Nuclear Information System (INIS)

    Mortazavi, S. M. J.; Mosleh-Shirazi, M. A.; Maheri, M. R.; Haji-pour, A.; Yousefnia, H.; Zolghadri, S.

    2007-01-01

    In megavoltage radiotherapy rooms, ordinary concrete is usually used due to its low construction costs, although higher density concrete are sometimes used, as well. The use of high-density concrete decreases the required thickness of the concrete barrier; hence, its disadvantage is its high cost. In a nuclear reactor, neutron radiation is the most difficult to shield. A method for production of economic high-density concrete witt, appropriate engineering properties would be very useful. Materials and Methods: Galena (Pb S) mineral was used to produce of a high-density concrete. Galena can be found in many parts of Iran. Two types of concrete mixes were produced. The water-to-concrete (w/c) ratios of the reference and galena concrete mixes were 0.53 and 0.25, respectively. To measure the gamma radiation attenuation of Galena concrete samples, they were exposed to a narrow beam of gamma rays emitted from a cobalt-60 therapy unit. Results: The Galena mineral used in this study had a density of 7400 kg/m 3 . The concrete samples had a density of 4800 kg/m 3 . The measured half value layer thickness of the Galena concrete samples for cobalt 60 gamma rays was much less than that of ordinary concrete (2.6 cm compared to 6.0 cm). Furthermore, the galena concrete samples had significantly higher compressive strength (500 kg/cm 2 compared to 300 kg/cm 2 ). Conclusion: The Galena concrete samples made in our laboratories had showed good shielding/engineering properties in comparison with all samples made by using high-density materials other than depleted uranium. Based on the preliminary results, Galena concrete is maybe a suitable option where high-density concrete is required in megavoltage radiotherapy rooms as well as nuclear reactors

  18. Solid-state circuits

    CERN Document Server

    Pridham, G J

    2013-01-01

    Solid-State Circuits provides an introduction to the theory and practice underlying solid-state circuits, laying particular emphasis on field effect transistors and integrated circuits. Topics range from construction and characteristics of semiconductor devices to rectification and power supplies, low-frequency amplifiers, sine- and square-wave oscillators, and high-frequency effects and circuits. Black-box equivalent circuits of bipolar transistors, physical equivalent circuits of bipolar transistors, and equivalent circuits of field effect transistors are also covered. This volume is divided

  19. Circuit analysis for dummies

    CERN Document Server

    Santiago, John

    2013-01-01

    Circuits overloaded from electric circuit analysis? Many universities require that students pursuing a degree in electrical or computer engineering take an Electric Circuit Analysis course to determine who will ""make the cut"" and continue in the degree program. Circuit Analysis For Dummies will help these students to better understand electric circuit analysis by presenting the information in an effective and straightforward manner. Circuit Analysis For Dummies gives you clear-cut information about the topics covered in an electric circuit analysis courses to help

  20. The MCD circuit based on FPGA

    International Nuclear Information System (INIS)

    Vu Quoc Trong

    2003-01-01

    Two MCD circuits based on different FPGA are presented as results of the study of the MAX+PLUS II software and FPGA devices. An external memory like 62256 and programmed EPM7064S will be able to form a MCD with 8 kilo channels. (NHA)

  1. Current limiter circuit system

    Science.gov (United States)

    Witcher, Joseph Brandon; Bredemann, Michael V.

    2017-09-05

    An apparatus comprising a steady state sensing circuit, a switching circuit, and a detection circuit. The steady state sensing circuit is connected to a first, a second and a third node. The first node is connected to a first device, the second node is connected to a second device, and the steady state sensing circuit causes a scaled current to flow at the third node. The scaled current is proportional to a voltage difference between the first and second node. The switching circuit limits an amount of current that flows between the first and second device. The detection circuit is connected to the third node and the switching circuit. The detection circuit monitors the scaled current at the third node and controls the switching circuit to limit the amount of the current that flows between the first and second device when the scaled current is greater than a desired level.

  2. Phase change memory

    CERN Document Server

    Qureshi, Moinuddin K

    2011-01-01

    As conventional memory technologies such as DRAM and Flash run into scaling challenges, architects and system designers are forced to look at alternative technologies for building future computer systems. This synthesis lecture begins by listing the requirements for a next generation memory technology and briefly surveys the landscape of novel non-volatile memories. Among these, Phase Change Memory (PCM) is emerging as a leading contender, and the authors discuss the material, device, and circuit advances underlying this exciting technology. The lecture then describes architectural solutions t

  3. Parallel basal ganglia circuits for decision making.

    Science.gov (United States)

    Hikosaka, Okihide; Ghazizadeh, Ali; Griggs, Whitney; Amita, Hidetoshi

    2018-03-01

    The basal ganglia control body movements, mainly, based on their values. Critical for this mechanism is dopamine neurons, which sends unpredicted value signals, mainly, to the striatum. This mechanism enables animals to change their behaviors flexibly, eventually choosing a valuable behavior. However, this may not be the best behavior, because the flexible choice is focused on recent, and, therefore, limited, experiences (i.e., short-term memories). Our old and recent studies suggest that the basal ganglia contain separate circuits that process value signals in a completely different manner. They are insensitive to recent changes in value, yet gradually accumulate the value of each behavior (i.e., movement or object choice). These stable circuits eventually encode values of many behaviors and then retain the value signals for a long time (i.e., long-term memories). They are innervated by a separate group of dopamine neurons that retain value signals, even when no reward is predicted. Importantly, the stable circuits can control motor behaviors (e.g., hand or eye) quickly and precisely, which allows animals to automatically acquire valuable outcomes based on historical life experiences. These behaviors would be called 'skills', which are crucial for survival. The stable circuits are localized in the posterior part of the basal ganglia, separately from the flexible circuits located in the anterior part. To summarize, the flexible and stable circuits in the basal ganglia, working together but independently, enable animals (and humans) to reach valuable goals in various contexts.

  4. Architectural Techniques to Enable Reliable and Scalable Memory Systems

    OpenAIRE

    Nair, Prashant J.

    2017-01-01

    High capacity and scalable memory systems play a vital role in enabling our desktops, smartphones, and pervasive technologies like Internet of Things (IoT). Unfortunately, memory systems are becoming increasingly prone to faults. This is because we rely on technology scaling to improve memory density, and at small feature sizes, memory cells tend to break easily. Today, memory reliability is seen as the key impediment towards using high-density devices, adopting new technologies, and even bui...

  5. Computational aspects of feedback in neural circuits.

    Directory of Open Access Journals (Sweden)

    Wolfgang Maass

    2007-01-01

    Full Text Available It has previously been shown that generic cortical microcircuit models can perform complex real-time computations on continuous input streams, provided that these computations can be carried out with a rapidly fading memory. We investigate the computational capability of such circuits in the more realistic case where not only readout neurons, but in addition a few neurons within the circuit, have been trained for specific tasks. This is essentially equivalent to the case where the output of trained readout neurons is fed back into the circuit. We show that this new model overcomes the limitation of a rapidly fading memory. In fact, we prove that in the idealized case without noise it can carry out any conceivable digital or analog computation on time-varying inputs. But even with noise, the resulting computational model can perform a large class of biologically relevant real-time computations that require a nonfading memory. We demonstrate these computational implications of feedback both theoretically, and through computer simulations of detailed cortical microcircuit models that are subject to noise and have complex inherent dynamics. We show that the application of simple learning procedures (such as linear regression or perceptron learning to a few neurons enables such circuits to represent time over behaviorally relevant long time spans, to integrate evidence from incoming spike trains over longer periods of time, and to process new information contained in such spike trains in diverse ways according to the current internal state of the circuit. In particular we show that such generic cortical microcircuits with feedback provide a new model for working memory that is consistent with a large set of biological constraints. Although this article examines primarily the computational role of feedback in circuits of neurons, the mathematical principles on which its analysis is based apply to a variety of dynamical systems. Hence they may also

  6. High density plasma productions by hydrogen storage electrode in the Tohoku University Heliac

    International Nuclear Information System (INIS)

    Utoh, H.; Takahashi, H.; Tanaka, Y.; Takenaga, M.; Ogawa, M.; Shinde, J.; Iwazaki, K.; Shinto, K.; Kitajima, S.; Sasao, M.; Nishimura, K.; Inagaki, S.

    2005-01-01

    In the Tohoku University Heliac (TU-Heliac), the influence of a radial electric field on improved modes has been investigated by an electrode biasing. In both positive and negative biasing experiments by the stainless steel (SUS) electrode (cold-electron or ion collection), the improvement of plasma confinement was clearly observed. Furthermore, by negative biasing with a hot cathode (electron injection), the radial electric fields can be actively controlled as a consequence of the control of the electrode current I E . By using the electrode made of a hydrogen storage metal, for example Titanium (Ti) or Vanadium (V), the following possibility can be expected: (1) ions accelerated from the positive biased electrode allow the simulation for the orbit loss of high-energy particles, (2) the electrons/neutral- particles injected from the negative biased electrode provide the production of the high- density plasma, if hydrogen are successfully stored in the electrode. In this present work, several methods were tried as the treatment for hydrogen storage. In the case of the Ti electrode biased positively after the treatment, the improvement of plasma confinement was observed in He plasma, which were same as the experimental results of the SUS electrode. However, in the electron density profiles inside the electrode position there was difference between the biased plasma by the Ti electrode and that by the SUS electrode. In some of Ar discharges biased negatively with the Ti electrode after the treatment, the electron density and the line intensity of H α increased about 10 times of those before biasing. This phenomenon has not been observed in the Ar plasma biased by the SUS electrode. This result suggested that the Ti electrode injected electrons/neutral-hydrogen into the plasma. This high-density plasma productions were observed only 1 ∼ 3 times in the one treatment for hydrogen storage. By using a Vanadium (V) electrode, productions of the high-density plasma

  7. The future of memory

    Science.gov (United States)

    Marinella, M.

    In the not too distant future, the traditional memory and storage hierarchy of may be replaced by a single Storage Class Memory (SCM) device integrated on or near the logic processor. Traditional magnetic hard drives, NAND flash, DRAM, and higher level caches (L2 and up) will be replaced with a single high performance memory device. The Storage Class Memory paradigm will require high speed (read/write), excellent endurance (> 1012), nonvolatility (retention > 10 years), and low switching energies (memory (PCM). All of these devices show potential well beyond that of current flash technologies and research efforts are underway to improve the endurance, write speeds, and scalabilities to be on-par with DRAM. This progress has interesting implications for space electronics: each of these emerging device technologies show excellent resistance to the types of radiation typically found in space applications. Commercially developed, high density storage class memory-based systems may include a memory that is physically radiation hard, and suitable for space applications without major shielding efforts. This paper reviews the Storage Class Memory concept, emerging memory devices, and possible applicability to radiation hardened electronics for space.

  8. Workshop on High Power ICH Antenna Designs for High Density Tokamaks

    Science.gov (United States)

    Aamodt, R. E.

    1990-02-01

    A workshop in high power ICH antenna designs for high density tokamaks was held to: (1) review the data base relevant to the high power heating of high density tokamaks; (2) identify the important issues which need to be addressed in order to ensure the success of the ICRF programs on CIT and Alcator C-MOD; and (3) recommend approaches for resolving the issues in a timely realistic manner. Some specific performance goals for the antenna system define a successful design effort. Simply stated these goals are: couple the specified power per antenna into the desired ion species; produce no more than an acceptable level of RF auxiliary power induced impurities; and have a mechanical structure which safely survives the thermal, mechanical and radiation stresses in the relevant environment. These goals are intimately coupled and difficult tradeoffs between scientific and engineering constraints have to be made.

  9. Workshop on high power ICH antenna designs for high density tokamaks

    International Nuclear Information System (INIS)

    Aamodt, R.E.

    1990-01-01

    A workshop in high power ICH antenna designs for high density tokamaks was held in Boulder, Colorado on January 31 through February 2, 1990. The purposes of the workshop were to: (1) review the data base relevant to the high power heating of high density tokamaks; (2) identify the important issues which need to be addressed in order to ensure the success of the ICRF programs on CIT and Alcator C-MOD; and (3) recommend approaches for resolving the issues in a timely realistic manner. Some specific performance goals for the antenna system define a successful design effort. Simply stated these goals are: couple the specified power per antenna into the desired ion species; produce no more than an acceptable level of rf auxiliary power induced impurities; and have a mechanical structure which safely survives the thermal, mechanical and radiation stresses in the relevant environment. These goals are intimately coupled and difficult tradeoffs between scientific and engineering constraints have to be made

  10. A complete life cycle assessment of high density polyethylene plastic bottle

    Science.gov (United States)

    Treenate, P.; Limphitakphong, N.; Chavalparit, O.

    2017-07-01

    This study was aimed to determine environmental performances of a lubricant oil bottle made from high density polyethylene and to develop potential measures for reducing its impacts. A complete life cycle assessment was carried out to understand a whole effect on the environment from acquiring, processing, using, and disposing the product. Two scenarios of disposal phase; recycle and incineration: were examined to quantify a lesser degree on environmental impact. The results illustrated that major impacts of the two scenarios were at the same categories with the highest contributor of raw material acquisition and pre-processing. However, all impacts in case of recycling provided a lower point than that in case of incineration, except mineral extraction. Finally, feasible measures for reducing the environmental impact of high density polyethylene plastic bottle were proposed in accordance with 3Rs concept.

  11. High-density near-field optical disc recording using phase change media and polycarbonate substrate

    Science.gov (United States)

    Shinoda, Masataka; Saito, Kimihiro; Ishimoto, Tsutomu; Kondo, Takao; Nakaoki, Ariyoshi; Furuki, Motohiro; Takeda, Minoru; Akiyama, Yuji; Shimouma, Takashi; Yamamoto, Masanobu

    2004-09-01

    We developed a high density near field optical recording disc system with a solid immersion lens and two laser sources. In order to realize the near field optical recording, we used a phase change recording media and a molded polycarbonate substrate. The near field optical pick-up consists of a solid immersion lens with numerical aperture of 1.84. The clear eye pattern of 90.2 GB capacity (160nm track pitch and 62 nm per bit) was observed. The jitter using a limit equalizer was 10.0 % without cross-talk. The bit error rate using an adaptive PRML with 8 taps was 3.7e-6 without cross-talk. We confirmed that the near field optical disc system is a promising technology for a next generation high density optical disc system.

  12. Evaluation of electrical crosstalk in high-density photodiode arrays for X-ray imaging applications

    International Nuclear Information System (INIS)

    Ji Fan; Juntunen, Mikko; Hietanen, Iiro

    2009-01-01

    Electrical crosstalk is one of the important parameters in the photodiode array detector for X-ray imaging applications, and it becomes more important when the density of the photodiode array becomes higher. This paper presents the design of the high-density photodiode array with 250 μm pitch and 50 μm gap. The electrical crosstalk of the demonstrated samples is evaluated and compared with different electrode configurations: cathode bias mode and anode bias mode. The measurement results show good electrical crosstalk, ∼0.23%, in cathode bias mode regardless of the bias voltage, and slightly decreased or increased electrical crosstalk in anode bias mode. Moreover, the quantum efficiency is also evaluated from the same samples, and it behaves similar to the electrical crosstalk. Finally, some design guidance of the high-density photodiode array is given based on the discussion.

  13. Density measurements of small amounts of high-density solids by a floatation method

    International Nuclear Information System (INIS)

    Akabori, Mitsuo; Shiba, Koreyuki

    1984-09-01

    A floatation method for determining the density of small amounts of high-density solids is described. The use of a float combined with an appropriate floatation liquid allows us to measure the density of high-density substances in small amounts. Using the sample of 0.1 g in weight, the floatation liquid of 3.0 g cm -3 in density and the float of 1.5 g cm -3 in apparent density, the sample densities of 5, 10 and 20 g cm -3 are determined to an accuracy better than +-0.002, +-0.01 and +-0.05 g cm -3 , respectively that correspond to about +-1 x 10 -5 cm 3 in volume. By means of appropriate degassing treatments, the densities of (Th,U)O 2 pellets of --0.1 g in weight and --9.55 g cm -3 in density were determined with an accuracy better than +-0.05 %. (author)

  14. High density lipoproteins as indicators of endothelial dysfunction in children with diadetes type I

    Directory of Open Access Journals (Sweden)

    Lobanova S.M.

    2011-12-01

    Full Text Available The aim of the investigation was to study the level of blood high density lipoproteins (HDL in the groups of children with different course of diadetes type I in order to find out the dependence of course and complications of diabetes on that level. Materials and methods: Blood high density lipoprotein (HDL levels were investigated in children and adolescents with diadetes type I, depending on the duration of diadetes type I, age, stage of sexual development, the stage of diabetic nephropathy and levels of plasma endothelin-1 (E-1. Results: Decrease in HDL level with increasing duration of diadetes type I in prepubertate patients, higher indices of HDL cholesterol were determined in girls, especially with impaired puberty. HDL cholesterol was higher in diabetic nephropathy at the stage of proteinuria and high level of blood endothelin-1. Conclusion: The revealed changes were considered to cause deregulation of vascular endothelium as a manifestation of the initial stages of endothelial dysfunction

  15. Equation-of-state for fluids at high densities-hydrogen isotope measurements and thermodynamic derivations

    International Nuclear Information System (INIS)

    Liebenberg, D.H.; Mills, R.L.; Bronson, J.C.

    1977-01-01

    Hydrogen isotopes play an important role in energy technologies, in particular, the compression to high densities for initiation of controlled thermonuclear fusion energy. At high densities the properties of the compressed hydrogen isotopes depart drastically from ideal thermodynamic predictions. The measurement of accurate data including the author's own recent measurements of n-H 2 and n-D 2 in the range 75 to 300 K and 0.2 to 2.0 GPa (2 to 20 kbar) is reviewed. An equation-of-state of the Benedict type is fit to these data with a double-process least-squares computer program. The results are reviewed and compared with existing data and with a variety of theoretical work reported for fluid hydrogens. A new heuristic correlation is presented for simplicity in predicting volumes and sound velocity at high pressures. 9 figures, 1 table

  16. The use of high-density concretes in radiotherapy treatment room design

    International Nuclear Information System (INIS)

    Facure, A.; Silva, A.X.

    2007-01-01

    With the modernization of radiotherapic centers, medical linear accelerators are largely replacing 60 Co teletherapy units. In many cases, the same vault housing the 60 Co teletherapy unit is reused for the linear accelerator and, when space is at a premium, high-density concrete (3.0-5.0 g/cm 3 ) is employed to provide shielding against the primary, scatter and leakage radiation. This work presents a study based on Monte Carlo simulations of transmission of some clinical photon spectra (of 4-10 MV accelerators) through some types of high-density concretes, normally used in the construction of radiotherapy bunkers. From the simulations, the initial and subsequent tenth-value layers (TVL) for these materials, taking into account realistic clinical photon spectra, are presented, for primary radiation

  17. High-density 3D graphene-based monolith and related materials, methods, and devices

    Energy Technology Data Exchange (ETDEWEB)

    Worsley, Marcus A.; Baumann, Theodore F.; Biener, Juergen; Charnvanichborikarn, Supakit; Kucheyev, Sergei; Montalvo, Elizabeth; Shin, Swanee; Tylski, Elijah

    2017-03-21

    A composition comprising at least one high-density graphene-based monolith, said monolith comprising a three-dimensional structure of graphene sheets crosslinked by covalent carbon bonds and having a density of at least 0.1 g/cm.sup.3. Also provided is a method comprising: preparing a reaction mixture comprising a suspension and at least one catalyst, said suspension selected from a graphene oxide (GO) suspension and a carbon nanotube suspension; curing the reaction mixture to produce a wet gel; drying the wet gel to produce a dry gel, said drying step is substantially free of supercritical drying and freeze drying; and pyrolyzing the dry gel to produce a high-density graphene-based monolith. Exceptional combinations of properties are achieved including high conductive and mechanical properties.

  18. High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

    International Nuclear Information System (INIS)

    Amendt, Peter; Ho, Darwin D.; Jones, Ogden S.

    2015-01-01

    A recent low gas-fill density (0.6 mg/cc 4 He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc 4 He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth

  19. High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

    Science.gov (United States)

    Amendt, Peter; Ho, Darwin D.; Jones, Ogden S.

    2015-04-01

    A recent low gas-fill density (0.6 mg/cc 4He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc 4He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth.

  20. High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

    Energy Technology Data Exchange (ETDEWEB)

    Amendt, Peter; Ho, Darwin D.; Jones, Ogden S. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

    2015-04-15

    A recent low gas-fill density (0.6 mg/cc {sup 4}He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc {sup 4}He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth.

  1. OSCAR experiment high-density network data report: Event 3 - April 16-17, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Dana, M.T.; Easter, R.C.; Thorp, J.M.

    1984-12-01

    The OSCAR (Oxidation and Scavenging Characteristics of April Rains) experiment, conducted during April 1981, was a cooperative field investigation of wet removal in cyclonic storm systems. The high-density component of OSCAR was located in northeast Indiana and included sequential precipitation chemistry measurements on a 100 by 100 km network, as well as airborne air chemistry and cloud chemistry measurements, surface air chemistry measurements, and supporting meteorological measurements. Four separate storm events were studied during the experiment. This report summarizes data taken by Pacific Northwest Laboratory (PNL) during the third storm event, April 16-17. The report contains the high-density network precipitation chemistry data, air chemistry and cloud chemistry data from the PNL aircraft, and meteorological data for the event, including standard National Weather Service products and radar and rawindsonde data from the network. 4 references, 76 figures, 6 tables.

  2. Thermal Experimental Analysis for Dielectric Characterization of High Density Polyethylene Nanocomposites

    Directory of Open Access Journals (Sweden)

    Ahmed Thabet Mohamed

    2016-01-01

    Full Text Available The importance of nanoparticles in controlling physical properties of polymeric nanocomposite materials leads us to study effects of these nanoparticles on electric and dielectric properties of polymers in industry In this research, the dielectric behaviour of High-Density Polyethylene (HDPE nanocomposites materials that filled with nanoparticles of clay or fumed silica has been investigated at various frequencies (10 Hz-1 kHz and temperatures (20-60°C. Dielectric spectroscopy has been used to characterize ionic conduction, then, the effects of nanoparticles concentration on the dielectric losses and capacitive charge of the new nanocomposites can be stated. Capacitive charge and loss tangent in high density polyethylene nanocomposites are measured by dielectric spectroscopy. Different dielectric behaviour has been observed depending on type and concentration of nanoparticles under variant thermal conditions.

  3. High density FTA plates serve as efficient long-term sample storage for HLA genotyping.

    Science.gov (United States)

    Lange, V; Arndt, K; Schwarzelt, C; Boehme, I; Giani, A S; Schmidt, A H; Ehninger, G; Wassmuth, R

    2014-02-01

    Storage of dried blood spots (DBS) on high-density FTA(®) plates could constitute an appealing alternative to frozen storage. However, it remains controversial whether DBS are suitable for high-resolution sequencing of human leukocyte antigen (HLA) alleles. Therefore, we extracted DNA from DBS that had been stored for up to 4 years, using six different methods. We identified those extraction methods that recovered sufficient high-quality DNA for reliable high-resolution HLA sequencing. Further, we confirmed that frozen whole blood samples that had been stored for several years can be transferred to filter paper without compromising HLA genotyping upon extraction. Concluding, DNA derived from high-density FTA(®) plates is suitable for high-resolution HLA sequencing, provided that appropriate extraction protocols are employed. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Fueling with edge recycling to high-density in DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, A.W., E-mail: leonard@fusion.gat.com [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Elder, J.D. [University of Toronto Institute of Aerospace Studies, Toronto, Canada M3H 5T6 (Canada); Canik, J.M. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Groebner, R.J.; Osborne, T.H. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States)

    2013-07-15

    Pedestal fueling through edge recycling is examined with the interpretive OEDGE code for high-density discharges in DIII-D. A high current, high-density discharge is found to have a similar radial ion flux profile through the pedestal to a lower current, lower density discharge. The higher density discharge, however, has a greater density gradient indicating a pedestal particle diffusion coefficient that scales near linear with 1/I{sub p}. The time dependence of density profile is taken into account in the analysis of a discharge with low frequency ELMs. The time-dependent analysis indicates that the inferred neutral ionization source is inadequate to account for the increase in the density profile between ELMs, implying an inward density convection, or density pinch, near the top of the pedestal.

  5. High density high performance plasma with internal diffusion barrier in Large Helical Device

    International Nuclear Information System (INIS)

    Sakamoto, R.; Kobayashi, M.; Miyazawa, J.

    2008-10-01

    A attractive high density plasma operational regime, namely an internal diffusion barrier (IDB), has been discovered in the intrinsic helical divertor configuration on the Large Helical Device (LHD). The IDB which enables core plasma to access a high density/high pressure regime has been developed. It is revealed that the IDB is reproducibly formed by pellet fueling in the magnetic configurations shifted outward in major radius. Attainable central plasma density exceeds 1x10 21 m -3 . Central pressure reaches 1.5 times atmospheric pressure and the central β value becomes fairly high even at high magnetic field, i.e. β(0)=5.5% at B t =2.57 T. (author)

  6. Implosion characteristics of deuterium--tritium pellets surrounded by high-density shells

    International Nuclear Information System (INIS)

    Fraley, G.S.

    1976-09-01

    The effect of high-density shells on deuterium-tritium pellets imploded by laser energy deposition or other means is investigated. Attention is centered on the inner parts of the pellet where hydrodynamics is the dominant mechanism. The implosions can then be characterized by a pressure boundary condition. Numerical solutions of the implosions are carried out over a wide range of parameters both for solid pellets and pellets with a central void

  7. Rheo-optical Raman study of microscopic deformation in high-density polyethylene under hot drawing

    OpenAIRE

    Kida, Takumitsu; Hiejima, Yusuke; Nitta, Koh-hei

    2015-01-01

    In situ observation of the microscopic structural changes in high-density polyethylene during hot drawing was performed by incorporating a temperature-controlled tensile machine into a Raman spectroscopy apparatus. It was found that the load sharing and molecular orientation during elongation drastically changed at 50°C. The microscopic stress of the crystalline chains decreased with increasing temperature and diminished around 50°C. Moreover, the orientation of the crystalline chains was gre...

  8. The speed of passionate love, as a subliminal prime: A high-density electrical neuroimaging stud

    OpenAIRE

    Cacioppo Stephanie; Grafton Scott T.; Bianchi-Demicheli F

    2012-01-01

    In line with the psychological model of self expansion recent neuroimaging evidence shows an overlap between the brain network mediating passionate love and that involved in self representation. Nevertheless little remains known about the temporal dynamics of these brain areas. To address this question we recorded brain activity from 20 healthy participants using high density electrophysiological recordings while participants were performing a cognitive priming paradigm known to activate the ...

  9. Single-Step Fabrication of High-Density Microdroplet Arrays of Low-Surface-Tension Liquids.

    Science.gov (United States)

    Feng, Wenqian; Li, Linxian; Du, Xin; Welle, Alexander; Levkin, Pavel A

    2016-04-01

    A facile approach for surface patterning that enables single-step fabrication of high-density arrays of low-surface-tension organic-liquid microdroplets is described. This approach enables miniaturized and parallel high-throughput screenings in organic solvents, formation of homogeneous arrays of hydrophobic nanoparticles, polymer micropads of specific shapes, and polymer microlens arrays. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. High-Density Renewable Fuels Based on the Selective Dimerization of Pinenes

    Science.gov (United States)

    2009-01-01

    RJ-5, significant ring strain contributing to a high heat of combustion (Table 1). Bulk agricultural waste products, such as cellulose and lignin , are...compact structures and reactive olefin functionalities, these molecules have sig- nificant potential as feedstocks for high-density renewable fuels.2b,7...potential to have heating values exceeding that of JP-10. Given the favorable potential net heat of combustion for these pinene dimers, reactivity

  11. High-density lipoproteins inhibit urate crystal-induced inflammation in mice

    OpenAIRE

    Scanu Anna; Luisetto Roberto; Oliviero Francesca; Gruaz Lyssia; Sfriso Paolo; Burger Danielle; Punzi Leonardo

    2015-01-01

    Objectives To investigate the effects and mechanisms of action of high density lipoproteins (HDL) in monosodium urate (MSU) crystal induced inflammation—that is gouty inflammation in vivo. Methods Air pouches raised on the backs of mice were injected with MSU crystals or tumour necrosis factor (TNF) in the presence or absence of HDL and/or interleukin (IL) 1 receptor antagonist (IL 1Ra) for 3 h. Leucocyte count and neutrophil percentage in pouch fluids were measured using a haemocytometer an...

  12. High Density Silver Nanowire Arrays using Self-ordered Anodic Aluminum Oxide (AAO) Membrane

    OpenAIRE

    Han, Young-Hwan

    2008-01-01

    High density silver nanowire arrays were synthesized through the self-ordered Anodic Aluminum Oxide (AAO) template. The pore size in the AAO membrane was confirmed by processing the widening porosity with a honeycomb structure with cross sections of 20nm, 50nm, and 100nm, by SEM. Pore numbers by unit area were consistent; only pore size changed. The synthesized silver nanowire, which was crystallized, was dense in the cross sections of the amorphous AAO membrane. The synthesized silver nanowi...

  13. Practical high-density shielding materials for medical linear accelerator rooms

    International Nuclear Information System (INIS)

    Barish, R.J.

    1990-01-01

    High-energy linear accelerators are replacing lower energy units in radiation therapy centers. Radiation protection requirements necessitate expensive reconstruction of existing treatment rooms to accommodate these new machines. We describe two shielding materials: one made by embedding small pieces of scrap steel in cement, and the other made with cast iron in cement. Both materials produce high-density barriers at low cost using standard construction methods

  14. Banks-Casher-type relation for the BCS gap at high density

    OpenAIRE

    Kanazawa, Takuya; Wettig, Tilo; Yamamoto, Naoki

    2012-01-01

    We derive a new Banks-Casher-type relation which relates the density of complex Dirac eigenvalues at the origin to the BCS gap of quarks at high density. Our relation is applicable to QCD and QCD-like theories without a sign problem, such as two-color QCD and adjoint QCD with baryon chemical potential, and QCD with isospin chemical potential. It provides us with a method to measure the BCS gap through the Dirac spectrum on the lattice.

  15. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  16. The circuit designer's companion

    CERN Document Server

    Williams, Tim

    1991-01-01

    The Circuit Designer's Companion covers the theoretical aspects and practices in analogue and digital circuit design. Electronic circuit design involves designing a circuit that will fulfill its specified function and designing the same circuit so that every production model of it will fulfill its specified function, and no other undesired and unspecified function.This book is composed of nine chapters and starts with a review of the concept of grounding, wiring, and printed circuits. The subsequent chapters deal with the passive and active components of circuitry design. These topics are foll

  17. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1972-01-01

    Electronic Devices and Circuits, Volume 3 provides a comprehensive account on electronic devices and circuits and includes introductory network theory and physics. The physics of semiconductor devices is described, along with field effect transistors, small-signal equivalent circuits of bipolar transistors, and integrated circuits. Linear and non-linear circuits as well as logic circuits are also considered. This volume is comprised of 12 chapters and begins with an analysis of the use of Laplace transforms for analysis of filter networks, followed by a discussion on the physical properties of

  18. Detection of an electron beam in a high density plasma via an electrostatic probe

    Science.gov (United States)

    Majeski, Stephen; Yoo, Jongsoo; Zweben, Stewart; Yamada, Masaaki; Ji, Hantao

    2017-10-01

    The perturbation in floating potential by an electron beam is detected by a 1D floating potential probe array to evaluate the use of an electron beam for magnetic field line mapping in the Magnetic Reconnection Experiment (MRX) plasma. The MRX plasma is relatively high density (1013 cm-3) and low temperature (5 eV). Beam electrons are emitted from a tungsten filament and are accelerated by a 200 V potential across the sheath. They stream along the magnetic field lines towards the probe array. The spatial electron beam density profile is assumed to be a Gaussian along the radial axis of MRX and the effective beam width is determined from the radial profile of the floating potential. The magnitude of the perturbation is in agreement with theoretical predictions and the location of the perturbation is also in agreement with field line mapping. In addition, no significant broadening of the electron beam is observed after propagation for tens of centimeters through the high density plasma. These results demonstrate that this method of field line mapping is, in principle, feasible in high density plasmas. This work is supported by the DOE Contract No. DE-AC0209CH11466.

  19. Effect of mix proportion of high density concrete on compressive strength, density and radiation absorption

    International Nuclear Information System (INIS)

    Noor Azreen Masenwat; Mohamad Pauzi Ismail; Suhairy Sani; Ismail Mustapha; Nasharuddin Isa; Mohamad Haniza Mahmud; Mohammad Shahrizan Samsu

    2014-01-01

    To prevent radiation leaks at nuclear reactors, high-density concrete is used as an absorbent material for radiation from spreading into the environment. High-density concrete is a mixture of cement, sand, aggregate (usually high-density minerals) and water. In this research, hematite stone is used because of its mineral density higher than the granite used in conventional concrete mixing. Mix concrete in this study were divided into part 1 and part 2. In part 1, the concrete mixture is designed with the same ratio of 1: 2: 4 but differentiated in terms of water-cement ratio (0.60, 0.65, 0.70, 0.75, 0.80 ). Whereas, in part 2, the concrete mixture is designed to vary the ratio of 1: 1: 2, 1: 1.5: 3, 1: 2: 3, 1: 3: 6, 1: 2: 6 with water-cement ratio (0.7, 0.8, 0.85, 0.9). In each section, the division has also performed in a mixture of sand and fine sand hematite. Then, the physical characteristics of the density and the compressive strength of the mixture of part 1 and part 2 is measured. Comparisons were also made in terms of absorption of radiation by Cs-137 and Co-60 source for each mix. This paper describes and discusses the relationship between the concrete mixture ratio, the relationship with the water-cement ratio, compressive strength, density, different mixture of sand and fine sand hematite. (author)

  20. Low-enriched uranium high-density target project. Compendium report

    Energy Technology Data Exchange (ETDEWEB)

    Vandegrift, George; Brown, M. Alex; Jerden, James L.; Gelis, Artem V.; Stepinski, Dominique C.; Wiedmeyer, Stanley; Youker, Amanda; Hebden, Andrew; Solbrekken, G; Allen, C; Robertson., D; El-Gizawy, Sherif; Govindarajan, Srisharan; Hoyer, Annemarie; Makarewicz, Philip; Harris, Jacob; Graybill, Brian; Gunn, Andy; Berlin, James; Bryan, Chris; Sherman, Steven; Hobbs, Randy; Griffin, F. P.; Chandler, David; Hurt, C. J.; Williams, Paul; Creasy, John; Tjader, Barak; McFall, Danielle; Longmire, Hollie

    2016-09-01

    At present, most 99Mo is produced in research, test, or isotope production reactors by irradiation of highly enriched uranium targets. To achieve the denser form of uranium needed for switching from high to low enriched uranium (LEU), targets in the form of a metal foil (~125-150 µm thick) are being developed. The LEU High Density Target Project successfully demonstrated several iterations of an LEU-fission-based Mo-99 technology that has the potential to provide the world’s supply of Mo-99, should major producers choose to utilize the technology. Over 50 annular high density targets have been successfully tested, and the assembly and disassembly of targets have been improved and optimized. Two target front-end processes (acidic and electrochemical) have been scaled up and demonstrated to allow for the high-density target technology to mate up to the existing producer technology for target processing. In the event that a new target processing line is started, the chemical processing of the targets is greatly simplified. Extensive modeling and safety analysis has been conducted, and the target has been qualified to be inserted into the High Flux Isotope Reactor, which is considered above and beyond the requirements for the typical use of this target due to high fluence and irradiation duration.

  1. Synthesis of high density aviation fuel with cyclopentanol derived from lignocellulose

    Science.gov (United States)

    Sheng, Xueru; Li, Ning; Li, Guangyi; Wang, Wentao; Yang, Jinfan; Cong, Yu; Wang, Aiqin; Wang, Xiaodong; Zhang, Tao

    2015-03-01

    For the first time, renewable high density aviation fuels were synthesized at high overall yield (95.6%) by the Guerbet reaction of cyclopentanol which can be derived from lignocellulose, followed by the hydrodeoxygenation (HDO). The solvent-free Guerbet reaction of cyclopentanol was carried out under the co-catalysis of solid bases and Raney metals. Among the investigated catalyst systems, the combinations of magnesium-aluminium hydrotalcite (MgAl-HT) and Raney Ni (or Raney Co) exhibited the best performances. Over them, high carbon yield (96.7%) of C10 and C15 oxygenates was achieved. The Guerbet reaction products were further hydrodeoxygenated to bi(cyclopentane) and tri(cyclopentane) over a series of Ni catalysts. These alkanes have high densities (0.86 g mL-1 and 0.91 g mL-1) and can be used as high density aviation fuels or additives to bio-jet fuel. Among the investigated HDO catalysts, the 35 wt.% Ni-SiO2-DP prepared by deposition-precipitation method exhibited the highest activity.

  2. Seismic and structural analysis of high density/consolidated spent fuel storage racks

    International Nuclear Information System (INIS)

    Shah, S.J.; Biddle, J.R.; Bennett, S.M.; Schechter, C.B.; Harstead, G.A.; Kopecky, B.

    1995-01-01

    In many nuclear power plants, existing storage racks are being replaced with high-density racks to accommodate the increasing inventory of spent fuel. In the hypothetical design considered here, the high-density arrangement of fuel assemblies, or consolidated fuel canisters, is accomplished through the use of borated stainless steel (BSS) plates acting as neutron absorbers. The high-density fuel racks are simply supported by the pool floor with no structural connections to adjacent racks or to the pool walls or floor. Therefore, the racks are free standing and may slide and tip. Several time history, nonlinear, seismic analyses are required to account for variations in the coefficient of friction, rack loading configuration, ad the type of the seismic event. This paper presents several of the mathematical models usually used. The models include features to allow sliding and tipping of the racks and to represent the hydrodynamic coupling which can occur between fuel assemblies and rack cells, between adjacent racks, and between the racks and the reinforced concrete walls. A detailed model representing a single rack is used to evaluate the 3-D loading effects. This model is a controlling case for the stress analysis. A 2-D multi-rack model representing a row of racks between the spent fuel pool walls is used to evaluate the change in gaps between racks. The racks are analyzed for the fuel loading conditions of consolidated, full, empty, and half-loaded with fuel assemblies

  3. X-ray CT high-density artefact suppression in the presence of bones

    Energy Technology Data Exchange (ETDEWEB)

    Wei Jikun [School of Health Sciences, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051 (United States); Chen Laigao [BioImaging Center of Emphasis, Pfizer Global Research and Development, 2800 Plymouth RD, Ann Arbor, MI 48105 (United States); Sandison, George A [School of Health Sciences, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051 (United States); Liang Yun [Department of Radiology, Indiana University Medical School, Indianapolis, IN 46202 (United States); Xu, Lisa X [School of Mechanical Engineering, 585 Purdue Mall, West Lafayette, IN 47907-2040 (United States)

    2004-12-21

    This paper presents a novel method of reducing x-ray CT high-density artefacts generated by metal objects when abundant bone structures are present in the region of interest. This method has an advantage over previously proposed methods since it heavily suppresses the metal artefacts without introducing extra bone artefacts. The method of suppression requires that bone pixels are isolated and segmented by thresholding. Then artificial CT numbers are assigned to the bone pixels so that their projection profiles are smooth and thus can be properly simulated by a polynomial interpolation. The projection profile of the metal object is then removed to fully suppress the artefacts. The resulting processed profile is fed to a reconstruction routine and the previously preserved bone pixels added back. The new method utilizes two important features of the CT image with metal artefacts: (a) metal and bone pixels are not severely affected by the high-density artefacts and (b) the high-density artefacts can be located in specific projection channels in the profile domain, although they are spread out in the image domain. This suppression method solves the problem of CT image artefacts arising from metal objects in the body. It has the potential to greatly improve diagnostic CT imaging in the presence of these objects and treatment planning that utilizes CT for patients with metal applicators (e.g., brachytherapy for cervix cancer and prostate cryotherapy)

  4. Genetic search for an optimal power flow solution from a high density cluster

    Energy Technology Data Exchange (ETDEWEB)

    Amarnath, R.V. [Hi-Tech College of Engineering and Technology, Hyderabad (India); Ramana, N.V. [JNTU College of Engineering, Jagityala (India)

    2008-07-01

    This paper proposed a novel method to solve optimal power flow (OPF) problems. The method is based on a genetic algorithm (GA) search from a High Density Cluster (GAHDC). The algorithm of the proposed method includes 3 stages, notably (1) a suboptimal solution is obtained via a conventional analytical method, (2) a high density cluster, which consists of other suboptimal data points from the first stage, is formed using a density-based cluster algorithm, and (3) a genetic algorithm based search is carried out for the exact optimal solution from a low population sized, high density cluster. The final optimal solution thoroughly satisfies the well defined fitness function. A standard IEEE 30-bus test system was considered for the simulation study. Numerical results were presented and compared with the results of other approaches. It was concluded that although there is not much difference in numerical values, the proposed method has the advantage of minimal computational effort and reduced CPU time. As such, the method would be suitable for online applications such as the present Optimal Power Flow problem. 24 refs., 2 tabs., 4 figs.

  5. Departure mechanisms for host search on high-density patches by the Meteorus pulchricornis.

    Science.gov (United States)

    Sheng, Sheng; Feng, Sufang; Meng, Ling; Li, Baoping

    2014-01-01

    Less attention has been paid to the parasitoid-host system in which the host occurs in considerably high density with a hierarchical patch structure in studies on time allocation strategies of parasitoids. This study used the parasitoid Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae) and the Oriental leafworm, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) as the parasitoids-host model system to investigate patch-leaving mechanisms as affected by the high-host density, hierarchical patch structure, and foraging behaviors on both former and current patches. The results showed that three out of eight covariates tested had significant effects on the patch-leaving tendency, including the host density, ovipositor insertion, and host rejection on the current patch. The parasitoid paid more visits to the patch with high-density hosts. While the patch with higher host densities decreased the leaving tendency, the spatial distribution of hosts examined had no effect on the leaving tendency. Both oviposition and host rejection decreased the patch-leaving tendency. The variables associated with the former patch, such as the host density and number of ovipositor insertions, however, did not have an effect on the leaving tendency. Our study suggested that M. pulchricornis females may use an incremental mechanism to exploit high-density patches to the fullest. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  6. X-ray CT high-density artefact suppression in the presence of bones

    International Nuclear Information System (INIS)

    Wei Jikun; Chen Laigao; Sandison, George A; Liang Yun; Xu, Lisa X

    2004-01-01

    This paper presents a novel method of reducing x-ray CT high-density artefacts generated by metal objects when abundant bone structures are present in the region of interest. This method has an advantage over previously proposed methods since it heavily suppresses the metal artefacts without introducing extra bone artefacts. The method of suppression requires that bone pixels are isolated and segmented by thresholding. Then artificial CT numbers are assigned to the bone pixels so that their projection profiles are smooth and thus can be properly simulated by a polynomial interpolation. The projection profile of the metal object is then removed to fully suppress the artefacts. The resulting processed profile is fed to a reconstruction routine and the previously preserved bone pixels added back. The new method utilizes two important features of the CT image with metal artefacts: (a) metal and bone pixels are not severely affected by the high-density artefacts and (b) the high-density artefacts can be located in specific projection channels in the profile domain, although they are spread out in the image domain. This suppression method solves the problem of CT image artefacts arising from metal objects in the body. It has the potential to greatly improve diagnostic CT imaging in the presence of these objects and treatment planning that utilizes CT for patients with metal applicators (e.g., brachytherapy for cervix cancer and prostate cryotherapy)

  7. Space Qualified, Radiation Hardened, Dense Monolithic Flash Memory, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Radiation hardened nonvolatile memories for space is still primarily confined to EEPROM. There is high density effective or cost effective NVM solution available to...

  8. Performance of synthetic antiferromagnetic racetrack memory: domain wall versus skyrmion

    KAUST Repository

    Tomasello, R; Puliafito, V; Martinez, E; Manchon, Aurelien; Ricci, M; Carpentieri, M; Finocchio, G

    2017-01-01

    A storage scheme based on racetrack memory, where the information can be coded in a domain or a skyrmion, seems to be an alternative to conventional hard disk drive for high density storage. Here, we perform a full micromagnetic study

  9. Josephson Thermal Memory

    Science.gov (United States)

    Guarcello, Claudio; Solinas, Paolo; Braggio, Alessandro; Di Ventra, Massimiliano; Giazotto, Francesco

    2018-01-01

    We propose a superconducting thermal memory device that exploits the thermal hysteresis in a flux-controlled temperature-biased superconducting quantum-interference device (SQUID). This system reveals a flux-controllable temperature bistability, which can be used to define two well-distinguishable thermal logic states. We discuss a suitable writing-reading procedure for these memory states. The time of the memory writing operation is expected to be on the order of approximately 0.2 ns for a Nb-based SQUID in thermal contact with a phonon bath at 4.2 K. We suggest a noninvasive readout scheme for the memory states based on the measurement of the effective resonance frequency of a tank circuit inductively coupled to the SQUID. The proposed device paves the way for a practical implementation of thermal logic and computation. The advantage of this proposal is that it represents also an example of harvesting thermal energy in superconducting circuits.

  10. Magnetic vortex racetrack memory

    Science.gov (United States)

    Geng, Liwei D.; Jin, Yongmei M.

    2017-02-01

    We report a new type of racetrack memory based on current-controlled movement of magnetic vortices in magnetic nanowires with rectangular cross-section and weak perpendicular anisotropy. Data are stored through the core polarity of vortices and each vortex carries a data bit. Besides high density, non-volatility, fast data access, and low power as offered by domain wall racetrack memory, magnetic vortex racetrack memory has additional advantages of no need for constrictions to define data bits, changeable information density, adjustable current magnitude for data propagation, and versatile means of ultrafast vortex core switching. By using micromagnetic simulations, current-controlled motion of magnetic vortices in cobalt nanowire is demonstrated for racetrack memory applications.

  11. A Guillemin type E pulse forming network as the driver for a pulsed, high density plasma source.

    Science.gov (United States)

    Rathod, Priyavandna J; Anitha, V P; Sholapurwala, Z H; Saxena, Y C

    2014-06-01

    A Guillemin type E pulse forming network (PFN) has been designed, developed, and tested for its application in generating high density (~1 × 10(18) m(-3)) plasmas. In the present study, plasma thus generated is utilized to investigate the interaction of high power microwaves (HPMs) with plasma in an experimental architecture known as SYMPLE (System for Microwave PLasma Experiment). Plasma discharges of ~100 μs (max) duration are to be produced, by delivering energy of 5 kJ stored in a PFN to the plasma source, a washer gun. The output of the PFN, in terms of its rise time, flat top and amplitude, needs to be tailored, depending on the experimental requirements. An ignitron (NL8900) trigger generator (ITG) is developed in-house to control the PFN discharge through the gun. This ITG is also to be used in a circuit that synchronizes the HPM and plasma shots, to ensure that HPM-plasma interaction takes place during a temporal regime where appropriate parametric conditions are satisfied. Hence it is necessary to retain the jitter within ±2.5 μs. Further, requirement on plasma quiescence (~10%) necessitates maintaining the ripple within 5%. The developmental work of the PFN, keeping in view the above criteria and the test results, is presented in this paper. The parameters of the PFN have been analytically approximated and verified with PSPICE simulation. The test results presented include rise time ~5-8 μs, flat top variable in the range 20-100 μs, ripple within ~1.5%, and jitter within ±2.5 μs, producing quiescent (plasma discharge meeting the experimental requirements.

  12. Evaluation of an analytic linear Boltzmann transport equation solver for high-density inhomogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Lloyd, S. A. M.; Ansbacher, W. [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada) and Department of Medical Physics, British Columbia Cancer Agency-Vancouver Island Centre, Victoria, British Columbia V8R 6V5 (Canada)

    2013-01-15

    Purpose: Acuros external beam (Acuros XB) is a novel dose calculation algorithm implemented through the ECLIPSE treatment planning system. The algorithm finds a deterministic solution to the linear Boltzmann transport equation, the same equation commonly solved stochastically by Monte Carlo methods. This work is an evaluation of Acuros XB, by comparison with Monte Carlo, for dose calculation applications involving high-density materials. Existing non-Monte Carlo clinical dose calculation algorithms, such as the analytic anisotropic algorithm (AAA), do not accurately model dose perturbations due to increased electron scatter within high-density volumes. Methods: Acuros XB, AAA, and EGSnrc based Monte Carlo are used to calculate dose distributions from 18 MV and 6 MV photon beams delivered to a cubic water phantom containing a rectangular high density (4.0-8.0 g/cm{sup 3}) volume at its center. The algorithms are also used to recalculate a clinical prostate treatment plan involving a unilateral hip prosthesis, originally evaluated using AAA. These results are compared graphically and numerically using gamma-index analysis. Radio-chromic film measurements are presented to augment Monte Carlo and Acuros XB dose perturbation data. Results: Using a 2% and 1 mm gamma-analysis, between 91.3% and 96.8% of Acuros XB dose voxels containing greater than 50% the normalized dose were in agreement with Monte Carlo data for virtual phantoms involving 18 MV and 6 MV photons, stainless steel and titanium alloy implants and for on-axis and oblique field delivery. A similar gamma-analysis of AAA against Monte Carlo data showed between 80.8% and 87.3% agreement. Comparing Acuros XB and AAA evaluations of a clinical prostate patient plan involving a unilateral hip prosthesis, Acuros XB showed good overall agreement with Monte Carlo while AAA underestimated dose on the upstream medial surface of the prosthesis due to electron scatter from the high-density material. Film measurements

  13. A memristor-based nonvolatile latch circuit

    International Nuclear Information System (INIS)

    Robinett, Warren; Pickett, Matthew; Borghetti, Julien; Xia Qiangfei; Snider, Gregory S; Medeiros-Ribeiro, Gilberto; Williams, R Stanley

    2010-01-01

    Memristive devices, which exhibit a dynamical conductance state that depends on the excitation history, can be used as nonvolatile memory elements by storing information as different conductance states. We describe the implementation of a nonvolatile synchronous flip-flop circuit that uses a nanoscale memristive device as the nonvolatile memory element. Controlled testing of the circuit demonstrated successful state storage and restoration, with an error rate of 0.1%, during 1000 power loss events. These results indicate that integration of digital logic devices and memristors could open the way for nonvolatile computation with applications in small platforms that rely on intermittent power sources. This demonstrated feasibility of tight integration of memristors with CMOS (complementary metal-oxide-semiconductor) circuitry challenges the traditional memory hierarchy, in which nonvolatile memory is only available as a large, slow, monolithic block at the bottom of the hierarchy. In contrast, the nonvolatile, memristor-based memory cell can be fast, fine-grained and small, and is compatible with conventional CMOS electronics. This threatens to upset the traditional memory hierarchy, and may open up new architectural possibilities beyond it.

  14. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  15. Elements configuration of the open lead test circuit

    Energy Technology Data Exchange (ETDEWEB)

    Fukuzaki, Yumi, E-mail: 14514@sr.kagawa-nct.ac.jp [Advanced course of Electronics, Information and Communication Engineering, National Institute of Technology, Kagawa College, 551 Koda, Mitoyo, Kagawa (Japan); Ono, Akira [Department of Communication Network Engineering, National Institute of Technology, Kagawa College, 551 Koda, Mitoyo, Kagawa (Japan)

    2016-07-06

    In the field of electronics, small electronic devices are widely utilized because they are easy to carry. The devices have various functions by user’s request. Therefore, the lead’s pitch or the ball’s pitch have been narrowed and high-density printed circuit board has been used in the devices. Use of the ICs which have narrow lead pitch makes normal connection difficult. When logic circuits in the devices are fabricated with the state-of-the-art technology, some faults have occurred more frequently. It can be divided into types of open faults and short faults. We have proposed a new test method using a test circuit in the past. This paper propose elements configuration of the test circuit.

  16. Elements configuration of the open lead test circuit

    International Nuclear Information System (INIS)

    Fukuzaki, Yumi; Ono, Akira

    2016-01-01

    In the field of electronics, small electronic devices are widely utilized because they are easy to carry. The devices have various functions by user’s request. Therefore, the lead’s pitch or the ball’s pitch have been narrowed and high-density printed circuit board has been used in the devices. Use of the ICs which have narrow lead pitch makes normal connection difficult. When logic circuits in the devices are fabricated with the state-of-the-art technology, some faults have occurred more frequently. It can be divided into types of open faults and short faults. We have proposed a new test method using a test circuit in the past. This paper propose elements configuration of the test circuit.

  17. Electric circuits essentials

    CERN Document Server

    REA, Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Electric Circuits I includes units, notation, resistive circuits, experimental laws, transient circuits, network theorems, techniques of circuit analysis, sinusoidal analysis, polyph

  18. Piezoelectric drive circuit

    Science.gov (United States)

    Treu, C.A. Jr.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes. 7 figs.

  19. Load testing circuit

    DEFF Research Database (Denmark)

    2009-01-01

    A load testing circuit a circuit tests the load impedance of a load connected to an amplifier. The load impedance includes a first terminal and a second terminal, the load testing circuit comprising a signal generator providing a test signal of a defined bandwidth to the first terminal of the load...

  20. Short-circuit logic

    NARCIS (Netherlands)

    Bergstra, J.A.; Ponse, A.

    2010-01-01

    Short-circuit evaluation denotes the semantics of propositional connectives in which the second argument is only evaluated if the first argument does not suffice to determine the value of the expression. In programming, short-circuit evaluation is widely used. A short-circuit logic is a variant of

  1. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2011-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  2. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2010-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  3. Emerging memory technologies design, architecture, and applications

    CERN Document Server

    2014-01-01

    This book explores the design implications of emerging, non-volatile memory (NVM) technologies on future computer memory hierarchy architecture designs. Since NVM technologies combine the speed of SRAM, the density of DRAM, and the non-volatility of Flash memory, they are very attractive as the basis for future universal memories. This book provides a holistic perspective on the topic, covering modeling, design, architecture and applications. The practical information included in this book will enable designers to exploit emerging memory technologies to improve significantly the performance/power/reliability of future, mainstream integrated circuits. • Provides a comprehensive reference on designing modern circuits with emerging, non-volatile memory technologies, such as MRAM and PCRAM; • Explores new design opportunities offered by emerging memory technologies, from a holistic perspective; • Describes topics in technology, modeling, architecture and applications; • Enables circuit designers to ex...

  4. Use of a high density lead glass tubing projection chamber in positron emission tomography and in high energy physics

    International Nuclear Information System (INIS)

    Conti, M.; Guerra, A.D.; Habel, R.; Mulera, T.; Perez-Mendez, V.; Schwartz, G.

    1985-10-01

    We describe the principle of operation of a high density Projection Chamber, in which the converter/radiator and drift field shaping structures are combined in the form of high density (5 to 6 g/cm 3 ) lead glass tubing. The main applications of this type of detector to Medical Physics (Positron Emission Tomography) and High Energy Physics (Electromagnetic Calorimetry) are discussed

  5. Combined analysis of six lipoprotein lipase genetic variants on triglycerides, high-density lipoprotein, and ischemic heart disease

    DEFF Research Database (Denmark)

    Wittrup, Hans H; Andersen, Rolf V; Tybjaerg-Hansen, Anne

    2006-01-01

    Genetic variants in lipoprotein lipase may affect triglycerides, high-density lipoprotein (HDL), and risk of ischemic heart disease (IHD).......Genetic variants in lipoprotein lipase may affect triglycerides, high-density lipoprotein (HDL), and risk of ischemic heart disease (IHD)....

  6. Pruning for crop regulation in high density guava (Psidium guajava L.) plantation

    Energy Technology Data Exchange (ETDEWEB)

    Thakre, M.; Lal, S.; Uniyal, S.; Goswami, A.K. Prakash. P.

    2016-11-01

    High density management and crop regulation are two important aspects in guava (Psidium guajava L.) production. Therefore, to find out the economic way of managing high density planting and crop regulation, the present work was carried out on 6-year-old guava trees of cv. Pant Prabhat under double-hedge row system of planting during 2009-10 and 2010-11. Seven different forms of pruning [FBT: flower bud thinning by hand, FBTT: flower bud thinning by hand followed by removal of terminal one leaf pair, RLFO: removal of leaves and flower buds by hand, retaining one leaf pair at the top, RLF: removal of all leaves and flowers by hand, OLPS: one leaf pair shoot pruning, FSP: full shoot pruning, OLPF: one leaf pair pruning of fruited shoots only] were studied along with control (C).Minimum annual increase in tree volume (6.764 m3) was recorded with the treatment OLPF, which was 2.31 times less than the control (15.682 m3). Highest yield during winter season (55.30 kg/tree) and total yield (59.87 kg/tree) was obtained from treatment OLPF. One leaf pair pruning of fruited shoots only (OLPF) was also found profitable among other treatments by recording cost:benefit ratio of 1:2.96. This treatment also recorded the highest return distributed in rainy as well as in winter season. On the basis of findings it can be concluded that one leaf pair pruning of fruited shoots only is suitable for profitable high density management as well as crop regulation of guava in farmer friendly manner. (Author)

  7. Pruning for crop regulation in high density guava (Psidium guajava L. plantation

    Directory of Open Access Journals (Sweden)

    Madhubala Thakre

    2016-06-01

    Full Text Available High density management and crop regulation are two important aspects in guava (Psidium guajava L. production. Therefore, to find out the economic way of managing high density planting and crop regulation, the present work was carried out on 6-year-old guava trees of cv. Pant Prabhat under double-hedge row system of planting during 2009-10 and 2010-11. Seven different forms of pruning [FBT: flower bud thinning by hand, FBTT: flower bud thinning by hand followed by removal of terminal one leaf pair, RLFO: removal of leaves and flower buds by hand, retaining one leaf pair at the top, RLF: removal of all leaves and flowers by hand, OLPS: one leaf pair shoot pruning, FSP: full shoot pruning, OLPF: one leaf pair pruning of fruited shoots only] were studied along with control (C.Minimum annual increase in tree volume (6.764 m3 was recorded with the treatment OLPF, which was 2.31 times less than the control (15.682 m3. Highest yield during winter season (55.30 kg/tree and total yield (59.87 kg/tree was obtained from treatment OLPF. One leaf pair pruning of fruited shoots only (OLPF was also found profitable among other treatments by recording cost:benefit ratio of 1:2.96. This treatment also recorded the highest return distributed in rainy as well as in winter season. On the basis of findings it can be concluded that one leaf pair pruning of fruited shoots only is suitable for profitable high density management as well as crop regulation of guava in farmer friendly manner.

  8. A study of HANARO core conversion using high density U-Mo fuel

    International Nuclear Information System (INIS)

    Lee, K.H.; Lee, C.S.; Lee, B.C.; Park, S.J.; Kim, H.; Kim, C.K.

    2002-01-01

    Currently, HANARO is using 3.15gU/cc U3Si/Al as a driver fuel. HANARO has seven vertical irradiation holes in the core region. Three of them including a central trap are located in the inner region of the core and mainly being used for material irradiation tests. Four of them are located in the reflector tank but cooled by primary coolant. They are used for fuel irradiation tests or radioisotope development tests. For minimum core modification using high density U-Mo fuels, no dimension change is assumed in the current fuel rods and the cladding thickness remains the same in this study. The high density U-Mo fuel will have up to about twice the linear uranium loading of a current HANARO driver fuel. Using this high density fuel 8 fuel sites can be replaced with irradiation sites. Three kinds of conceptual cores are considered using 5 gU/cc U-7Mo/Al and 16 gU/cc U-7Mo. The increase of the linear heat generation rate due to the decrease of total fuel length can be overcome by more uniform radial and axial power distribution using different uranium densities and different fuel meat diameters are introduced into those cores. The new core has 4.54 times larger surface-to-volume ratio than the reference core. The core uranium loading, linear heat generation rate, excess reactivity, and control rod worth as well as the neutron spectra are analysed for each core. (author)

  9. Hydrological impact of high-density small dams in a humid catchment, Southeast China

    Science.gov (United States)

    Lu, W.; Lei, H.; Yang, D.

    2017-12-01

    The Jiulong River basin is a humid catchment with a drainage area of 14,741 km2; however, it has over 1000 hydropower stations within it. Such catchment with high-density small dams is scarce in China. Yet few is known about the impact of high-density small dams on streamflow changes. To what extent the large number of dams alters the hydrologic patterns is a fundamental scientific issue for water resources management, flood control, and aquatic ecological environment protection. Firstly, trend and change point analyses are applied to determine the characteristics of inter-annual streamflow. Based on the detected change point, the study period is divided into two study periods, the ``natural'' and ``disturbed'' periods. Then, a geomorphology-based hydrological model (GBHM) and the fixing-changing method are adopted to evaluate the relative contributions of climate variations and damming to the changes in streamflow at each temporal scale (i.e., from daily, monthly to annual). Based on the simulated natural streamflow, the impact of dam construction on hydrologic alteration and aquatic ecological environment will be evaluated. The hydrologic signatures that will be investigated include flood peak, seasonality of streamflow, and the inter-annual variability of streamflow. In particular, the impacts of damming on aquatic ecological environment will be investigated using eco-flow metrics and indicators of hydrologic alteration (IHA) which contains 33 individual streamflow statistics that are closely related to aquatic ecosystem. The results of this study expect to provide a reference for reservoir operation considering both ecological and economic benefits of such operations in the catchment with high-density dams.

  10. Nuclear matter at high density: Phase transitions, multiquark states, and supernova outbursts

    International Nuclear Information System (INIS)

    Krivoruchenko, M. I.; Nadyozhin, D. K.; Rasinkova, T. L.; Simonov, Yu. A.; Trusov, M. A.; Yudin, A. V.

    2011-01-01

    Phase transition from hadronic matter to quark-gluon matter is discussed for various regimes of temperature and baryon number density. For small and medium densities, the phase transition is accurately described in the framework of the Field Correlation Method, whereas at high density predictions are less certain and leave room for the phenomenological models. We study formation of multiquark states (MQS) at zero temperature and high density. Relevant MQS components of the nuclear matter can be described using a previously developed formalism of the quark compound bags (QCB). Partialwave analysis of nucleon-nucleon scattering indicates the existence of 6QS which manifest themselves as poles of P matrix. In the framework of the QCB model, we formulate a self-consistent system of coupled equations for the nucleon and 6QS propagators in nuclear matter and the G matrix. The approach provides a link between high-density nuclear matter with the MQS components and the cumulative effect observed in reactions on the nuclei, which requires the admixture of MQS in the wave functions of nuclei kinematically. 6QS determines the natural scale of the density for a possible phase transition into theMQS phase of nuclear matter. Such a phase transition can lead to dynamic instability of newly born protoneutron stars and dramatically affect the dynamics of supernovae. Numerical simulations show that the phase transition may be a good remedy for the triggering supernova explosions in the spherically symmetric supernovamodels. A specific signature of the phase transition is an additional neutrino peak in the neutrino light curve. For a Galactic core-collapse supernova, such a peak could be resolved by the present neutrino detectors. The possibility of extracting the parameters of the phase of transition from observation of the neutrino signal is discussed also.

  11. Nuclear matter at high density: Phase transitions, multiquark states, and supernova outbursts

    Energy Technology Data Exchange (ETDEWEB)

    Krivoruchenko, M. I.; Nadyozhin, D. K.; Rasinkova, T. L.; Simonov, Yu. A.; Trusov, M. A., E-mail: trusov@itep.ru; Yudin, A. V. [Institute for Theoretical and Experimental Physics (Russian Federation)

    2011-03-15

    Phase transition from hadronic matter to quark-gluon matter is discussed for various regimes of temperature and baryon number density. For small and medium densities, the phase transition is accurately described in the framework of the Field Correlation Method, whereas at high density predictions are less certain and leave room for the phenomenological models. We study formation of multiquark states (MQS) at zero temperature and high density. Relevant MQS components of the nuclear matter can be described using a previously developed formalism of the quark compound bags (QCB). Partialwave analysis of nucleon-nucleon scattering indicates the existence of 6QS which manifest themselves as poles of P matrix. In the framework of the QCB model, we formulate a self-consistent system of coupled equations for the nucleon and 6QS propagators in nuclear matter and the G matrix. The approach provides a link between high-density nuclear matter with the MQS components and the cumulative effect observed in reactions on the nuclei, which requires the admixture of MQS in the wave functions of nuclei kinematically. 6QS determines the natural scale of the density for a possible phase transition into theMQS phase of nuclear matter. Such a phase transition can lead to dynamic instability of newly born protoneutron stars and dramatically affect the dynamics of supernovae. Numerical simulations show that the phase transition may be a good remedy for the triggering supernova explosions in the spherically symmetric supernovamodels. A specific signature of the phase transition is an additional neutrino peak in the neutrino light curve. For a Galactic core-collapse supernova, such a peak could be resolved by the present neutrino detectors. The possibility of extracting the parameters of the phase of transition from observation of the neutrino signal is discussed also.

  12. High triglycerides and low high-density lipoprotein cholesterol lipid profile in rheumatoid arthritis: A potential link among inflammation, oxidative status, and dysfunctional high-density lipoprotein.

    Science.gov (United States)

    Rodríguez-Carrio, Javier; Alperi-López, Mercedes; López, Patricia; López-Mejías, Raquel; Alonso-Castro, Sara; Abal, Francisco; Ballina-García, Francisco J; González-Gay, Miguel Á; Suárez, Ana

    The interactions between inflammation and lipid profile in rheumatoid arthritis (RA) are poorly understood. The lipid profile study in RA has been biased toward lipoprotein levels, whereas those of triglycerides (TGs) and lipoprotein functionality have been underestimated. Since recent findings suggest a role for TG and TG-rich lipoproteins (TRL) on inflammation, we aimed to evaluate a combined lipid profile characterized by high TG and low high-density lipoprotein cholesterol levels (TG high HDL low ) in RA. Lipid profiles were analyzed in 113 RA patients, 113 healthy controls, and 27 dyslipemic subjects. Levels of inflammatory mediators, paraoxonase-1 (PON1) activity, and total antioxidant capacity were quantified in serum. PON1-rs662 status was evaluated by real-time polymerase chain reaction. The TG high HDL low profile was detected in 29/113 RA patients. Although no differences in prevalence compared with healthy controls or dyslipemic subjects were observed, this profile was associated with increased tumor necrosis factor α (P = .004), monocyte chemotactic protein (P = .004), interferon-gamma-inducible protein-10 (P = .018), and leptin (P < .001) serum levels in RA, where decreased PON1 activity and total antioxidant capacity were found. TG high HDL low prevalence was lower among anti-TNFα-treated patients (P = .004). When RA patients were stratified by PON1-rs662 status, these associations remained in the low-activity genotype (QQ). Finally, a poor clinical response on TNFα blockade was related to an increasing prevalence of the TG high HDL low profile over treatment (P = .021) and higher TRL levels at baseline (P = .042). The TG high HDL low profile is associated with systemic inflammation, decreased PON1 activity, and poor clinical outcome on TNFα blockade in RA, suggesting a role of TRL and HDL dysfunction as the missing link between inflammation and lipid profile. Copyright © 2017 National Lipid Association. Published by Elsevier Inc

  13. Cylindrical implosion to measure the radiative properties of high density and temperature plasmas

    International Nuclear Information System (INIS)

    Xu Yan; Rose, S.J.

    2000-01-01

    Cylindrical implosion is of great interest because of its excellent diagnostic access. The authors present one-dimensional numerical simulations to explore the plasma conditions that may be achieved. Combined with the numerical data, the development of Rayleigh-Taylor instabilities and Richtmyer-Meshkov instabilities in those targets are estimated. The authors found that it is possible to achieve a high density and temperature plasma with a relatively low temperature and density gradient using a cylindrical implosion directly-driven by a high-power laser

  14. High density, uniformly distributed W/UO2 for use in Nuclear Thermal Propulsion

    Science.gov (United States)

    Tucker, Dennis S.; Barnes, Marvin W.; Hone, Lance; Cook, Steven

    2017-04-01

    An inexpensive, quick method has been developed to obtain uniform distributions of UO2 particles in a tungsten matrix utilizing 0.5 wt percent low density polyethylene. Powders were sintered in a Spark Plasma Sintering (SPS) furnace at 1600 °C, 1700 °C, 1750 °C, 1800 °C and 1850 °C using a modified sintering profile. This resulted in a uniform distribution of UO2 particles in a tungsten matrix with high densities, reaching 99.46% of theoretical for the sample sintered at 1850 °C. The powder process is described and the results of this study are given below.

  15. PRODUCTION OF HIGH DENSITY PARTICLEBOARD USING MELAMINE-UREA-FORMALDEHYDE RESIN

    Directory of Open Access Journals (Sweden)

    Setsuo Iwakiri

    2005-12-01

    Full Text Available This research was developed aiming to evaluate the effects of board density and melamine-urea-formaldehyde resin onthe properties of particleboard for semi-structural applications. The boards were manufactured with nominal density of 0.65 g/cm³and 0.90 g/cm³ using urea-formaldehyde resin as control and melamine-urea-formaldehyde. The results showed a better dimensionallystability and mechanical properties of the boards manufactured with higher density and MUF resin content. The fine furnish usedfor external layer of particleboard in the industrial process, could be used for high density homogeneous board to semi-strucuturaluses, such as flooring applications.

  16. High-Density Near-Field Readout Using Diamond Solid Immersion Lens

    Science.gov (United States)

    Shinoda, Masataka; Saito, Kimihiro; Kondo, Takao; Nakaoki, Ariyoshi; Furuki, Motohiro; Takeda, Minoru; Yamamoto, Masanobu; Schaich, Thomas J.; van Oerle, Bart M.; Godfried, Herman P.; Kriele, Paul A. C.; Houwman, Evert P.; Nelissen, Wim H. M.; Pels, Gert J.; Spaaij, Paul G. M.

    2006-02-01

    We investigated high-density near-field readout using a diamond solid immersion lens (SIL). A synthetic single-crystal chemical vapor deposition diamond provides a high refractive index and a high transmission for a wide wavelength range. Since the refractive index at a wavelength of 405 nm is 2.458, we could design a solid immersion lens with an effective numerical aperture of 2.34. Using the diamond SIL, we observed the eye pattern of a 150-GB-capacity (104.3 Gbit/in.2) disk with a track pitch of 130 nm and a bit length of 47.6 nm.

  17. Radiative recombination process of high density excitons in CdS crystals

    Energy Technology Data Exchange (ETDEWEB)

    Dneprovskij, V.S.; Klimov, V.I.; Martynenko, E.D.; Stadnik, V.A.

    1983-11-01

    The behaviour of the P-, E-, L- and Q-lines of luminescence in CdS is compared with calculated results for the processes of exciton-exciton scattering, exciton-electron scattering, annihilation of equilibrium electron-hole fluid (EHF), annihilation of electron-hole plasma (processes of amplification and reabsorption are taken into account). The comparison permitted to determine parameters of high density exciton gas and EHF. Spectral-kinetic properties of generation are investigated, and amplification factor in CdS is estimated.

  18. High-density EMG e-textile systems for the control of active prostheses

    DEFF Research Database (Denmark)

    Farina, Dario; Lorrain, Thomas; Negro, Francesco

    2010-01-01

    Myoelectric control of active prostheses requires electrode systems that are easy to apply for daily repositioning of the electrodes by the user. In this study we propose the use of Smart Fabric and Interactive Textile (SFIT) systems as an alternative solution for recording high-density EMG signa...... classified with linear discriminant analysis. The average classification accuracy for the nine tasks was 89.1 1.9 %. These results show that SFIT systems can be used as an effective way for muscle-machine interfacing....

  19. Analysis and Environmental Fate of Air Force Distillate and High Density Fuels

    Science.gov (United States)

    1981-10-01

    728.1 128 0.8 Toluenc 751.3 92 0.6 XTHDCPD 1049.6 136 66.8 NTHDCPD 1079.2 136 1.5HNN 1509.6 186 20.1 JP-1O XTHDCPD 1050.3 136 96.8 ITHDCPD 1079.6 136 1,5...deionized water and the salts listed below. Blanks of both waters were routinely extracted and analyzed for possible 4.nterferences. MNN PXTX XTHDCPD ...through 13; complete data summaries for the distillate fuels may be found in Appendix C. All com- ponents of the high density fuels except XTHDCPD of

  20. In vitro experiments for the development of a high density (HD) barium sulfate contrast medium

    International Nuclear Information System (INIS)

    Klein, J.

    1986-01-01

    In vitro experiments with the high-density (HD) barium meal Falibaryt HD are described. Several charges of BaSO 4 were tested together with certain additives influencing dispersion, stability of the suspension, flowability, surface tension etc. Particle size spectra were measured by the manufacturer, VEB Fahlberg-List. With a simple PVC test plate containing several grooves simulating small details (areae gastricae) the diagnostic capabilities of the HD contrast medium were evaluated in an in vitro test. The developed barium meal Falibaryt HD is in its physical and chemical parameters comparable with Prontobario-HD, one of the best HD barium meals. (author)

  1. High-Density Livestock Production and Molecularly Characterized MRSA Infections in Pennsylvania

    Science.gov (United States)

    Casey, Joan A.; Shopsin, Bo; Cosgrove, Sara E.; Nachman, Keeve E.; Curriero, Frank C.; Rose, Hannah R.

    2014-01-01

    Background: European studies suggest that living near high-density livestock production increases the risk of sequence type (ST) 398 methicillin-resistant Staphylococcus aureus (MRSA) colonization. To our knowledge, no studies have evaluated associations between livestock production and human infection by other strain types. Objectives: We evaluated associations between MRSA molecular subgroups and high-density livestock production. Methods: We conducted a yearlong 2012 prospective study on a stratified random sample of patients with culture-confirmed MRSA infection; we oversampled patients from the Geisinger Health System with exposure to high-density livestock production in Pennsylvania. Isolates were characterized using S. aureus protein A (spa) typing and detection of Panton-Valentine leukocidin (PVL) and scn genes. We compared patients with one of two specific MRSA strains with patients with all other strains of MRSA isolates, using logistic regression that accounted for the sampling design, for two different exposure models: one based on the location of the animals (livestock model) and the other on crop field application of manure (crop field model). Results: Of 196 MRSA isolates, we identified 30 spa types, 47 PVL-negative and 15 scn-negative isolates, and no ST398 MRSA. Compared with quartiles 1–3 combined, the highest quartiles of swine livestock and dairy/veal crop field exposures were positively associated with community-onset-PVL-negative MRSA (CO-PVL-negative MRSA vs. all other MRSA), with adjusted odds ratios of 4.24 (95% CI: 1.60, 11.25) and 4.88 (95% CI: 1.40, 17.00), respectively. The association with CO-PVL-negative MRSA infection increased across quartiles of dairy/veal livestock exposure (trend p = 0.05). Conclusions: Our findings suggest that other MRSA strains, beyond ST398, may be involved in livestock-associated MRSA infection in the United States. Citation: Casey JA, Shopsin B, Cosgrove SE, Nachman KE, Curriero FC, Rose HR, Schwartz BS

  2. Preparation of high density (8 to 9) uranium oxide UO2

    International Nuclear Information System (INIS)

    Eichner, C.; Ertaud, A.; Ortel, Y.; Stohr, J.; Vautrey, L.

    1948-10-01

    This report describes the process elaborated for the preparation of high density UO 2 . The thermal decomposition of uranium peroxide leads to UO 3 which is reduced by an hydrogen flow to obtain UO 2 . A UO 2 powder of good quality is obtained for temperatures below 650 deg. C. The powder is pulverized to obtain an homogeneous grain size and compressed inside a die to make pellets. Pellets are sintered up to 1600 deg. C in a reducing atmosphere and following a temperature rise law of 150 deg. C/hour. The equipment used (furnaces, gases purifier, control equipment, power supplies, thermoregulation systems) is described at the end. (J.S.)

  3. Triton-3He relative and differential flows and the high density behavior of nuclear symmetry

    International Nuclear Information System (INIS)

    Yong, Gaochan; Li, Baoan; Chen, Liewen

    2010-01-01

    Using a transport model coupled with a phase-space coalescence after-burner we study the triton- 3 He relative and differential transverse flows in semi-central 132 Sn + 124 Sn reactions at a beam energy of 400 MeV/nucleon. We find that the triton- 3 He pairs carry interesting information about the density dependence of the nuclear symmetry energy. The t- 3 He relative flow can be used as a particularly powerful probe of the high-density behavior of the nuclear symmetry energy. (author)

  4. Neutrino hierarchy from CP-blind observables with high density magnetized detectors

    International Nuclear Information System (INIS)

    Donini, A.; Fernandez-Martinez, E.; Rigolin, S.; Migliozzi, P.; Scotto Lavina, L.; Selvi, M.; Tabarelli de Fatis, T.; Terranova, F.

    2008-01-01

    High density magnetized detectors are well suited to exploit the outstanding purity and intensities of novel neutrino sources like neutrino factories and beta beams. They can also provide independent measurements of leptonic mixing parameters through the observation of atmospheric muon-neutrinos. In this paper, we discuss the combination of these observables from a multi-kT iron detector and a high energy beta beam; in particular, we demonstrate that even with moderate detector granularities the neutrino mass hierarchy can be determined for θ 13 values greater than 4 . (orig.)

  5. Accident Analysis of High Density Storage Rack for Fresh Fuel Assemblies

    International Nuclear Information System (INIS)

    Jang, K. J.; Lee, M. J.; Jin, H. U.; Park, J. H.; Shin, S. Y.

    2009-01-01

    Recently KONES and KNF have developed the so called suspension-type High Density Storage Rack (HDSR) for fresh fuel assemblies. The USNRC OT position paper specifies that the design of the rack must ensure the functional integrity of the fuel racks under all credible fuel assembly drop events. In this context the functional integrity means the criticality safety. That is to say, the drop events must not bring any danger to the criticality safety of HDSR. This paper shows the results of the analysis carried out to demonstrate the regulatory compliance of the proposed racks under postulated accidental drop events

  6. Emissions from heavy current carrying high density plasma and their diagnostics

    International Nuclear Information System (INIS)

    Hirano, Katsumi

    1987-06-01

    Workshop on ''Emissions from heavy current carrying high density plasma and diagnostics'' was held at Institute of Plasma Physics, Nagoya University on 3. and 4. December 1986 under a collaborating research Program. The workshop was attended by 43 researchers from 19 labolatories. A total of 22 papers were submitted and are presented in these proceedings. The largest group of papers was that on soft X-ray emission. It seems this topic is a foremost interest for groups which engaged in research of the Z pinch and the plasma focus. A variety of problems in pinched dense plasmas, namely spectroscopy, diagnostics, pinch dynamics, and related engineering aspects were also discussed. (author)

  7. Broadband infrared photoluminescence in silicon nanowires with high density stacking faults.

    Science.gov (United States)

    Li, Yang; Liu, Zhihong; Lu, Xiaoxiang; Su, Zhihua; Wang, Yanan; Liu, Rui; Wang, Dunwei; Jian, Jie; Lee, Joon Hwan; Wang, Haiyan; Yu, Qingkai; Bao, Jiming

    2015-02-07

    Making silicon an efficient light-emitting material is an important goal of silicon photonics. Here we report the observation of broadband sub-bandgap photoluminescence in silicon nanowires with a high density of stacking faults. The photoluminescence becomes stronger and exhibits a blue shift under higher laser powers. The super-linear dependence on excitation intensity indicates a strong competition between radiative and defect-related non-radiative channels, and the spectral blue shift is ascribed to the band filling effect in the heterostructures of wurtzite silicon and cubic silicon created by stacking faults.

  8. Study and application of high-density concrete in radiation-shielding experiment

    International Nuclear Information System (INIS)

    Wu Chongming; Ding Dexin; Xiao Xuefu; Wang Shaolin; Lin Xingjun; Shen Yuanyuan

    2008-01-01

    According to the demand for research and construction project, a series of systematic experiments and studies on shielding γ-ray radiation concrete with the density of 4.60 t/m 3 were made in such aspects as mix ratio design, construction technology, uniformly shielding etc. Such issues as uniformity in the construction and compactness were solved. The ray test method for uniformly shielding concrete was presented and some technical steps for this high-density concrete used in the process of test design or construction were summed up. A series of tests and practical applications show that this technology of mix ratio design and construction is feasible. (authors)

  9. Evaluation of AMPX-KENO benchmark calculations for high-density spent fuel storage racks

    International Nuclear Information System (INIS)

    Turner, S.E.; Gurley, M.K.

    1981-01-01

    The AMPX-KENO computer code package is commonly used to evaluate criticality in high-density spent fuel storage rack designs. Consequently, it is important to know the reliability that can be placed on such calculations and whether or not the results are conservative. This paper evaluates a series of AMPX-KENO calculations which have been made on selected critical experiments. The results are compared with similar analyses reported in the literature by the Oak Ridge National Laboratory and BandW. 8 refs

  10. Novel technique of making thin target foil of high density material via rolling method

    Science.gov (United States)

    Gupta, C. K.; Rohilla, Aman; Singh, R. P.; Singh, Gurjot; Chamoli, S. K.

    2018-05-01

    The conventional rolling method fails to yield good quality thin foils of thicknesses less than 2 mg/cm2 for high density materials with Z ≥ 70 (e.g. gold, lead). A special and improved technique has been developed to obtain such low thickness good quality gold foils by rolling method. Using this technique thin gold foils of thickness in the range of 0.850-2.5 mg/cm2 were obtained in the present work. By making use of alcohol during rolling, foils of thickness 1 mg/cm2 can be obtained in shorter time with less effort.

  11. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  12. Topographic and sex-related differences in sleep spindles in major depressive disorder: a high-density EEG investigation.

    Science.gov (United States)

    Plante, D T; Goldstein, M R; Landsness, E C; Peterson, M J; Riedner, B A; Ferrarelli, F; Wanger, T; Guokas, J J; Tononi, G; Benca, R M

    2013-03-20

    Sleep spindles are believed to mediate several sleep-related functions including maintaining disconnection from the external environment during sleep, cortical development, and sleep-dependent memory consolidation. Prior studies that have examined sleep spindles in major depressive disorder (MDD) have not demonstrated consistent differences relative to control subjects, which may be due to sex-related variation and limited spatial resolution of spindle detection. Thus, this study sought to characterize sleep spindles in MDD using high-density electroencephalography (hdEEG) to examine the topography of sleep spindles across the cortex in MDD, as well as sex-related variation in spindle topography in the disorder. All-night hdEEG recordings were collected in 30 unipolar MDD participants (19 women) and 30 age and sex-matched controls. Topography of sleep spindle density, amplitude, duration, and integrated spindle activity (ISA) were assessed to determine group differences. Spindle parameters were compared between MDD and controls, including analysis stratified by sex. As a group, MDD subjects demonstrated significant increases in frontal and parietal spindle density and ISA compared to controls. When stratified by sex, MDD women demonstrated increases in frontal and parietal spindle density, amplitude, duration, and ISA; whereas MDD men demonstrated either no differences or decreases in spindle parameters. Given the number of male subjects, this study may be underpowered to detect differences in spindle parameters in male MDD participants. This study demonstrates topographic and sex-related differences in sleep spindles in MDD. Further research is warranted to investigate the role of sleep spindles and sex in the pathophysiology of MDD. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Retrieving fear memories, as time goes by…

    Science.gov (United States)

    Do Monte, Fabricio H.; Quirk, Gregory J.; Li, Bo; Penzo, Mario A.

    2016-01-01

    Fear conditioning researches have led to a comprehensive picture of the neuronal circuit underlying the formation of fear memories. In contrast, knowledge about the retrieval of fear memories is much more limited. This disparity may stem from the fact that fear memories are not rigid, but reorganize over time. To bring clarity and raise awareness on the time-dependent dynamics of retrieval circuits, we review current evidence on the neuronal circuitry participating in fear memory retrieval at both early and late time points after conditioning. We focus on the temporal recruitment of the paraventricular nucleus of the thalamus, and its BDNFergic efferents to the central nucleus of the amygdala, for the retrieval and maintenance of fear memories. Finally, we speculate as to why retrieval circuits change across time, and the functional benefits of recruiting structures such as the paraventricular nucleus into the retrieval circuit. PMID:27217148

  14. Impact of hydrogen dilution on optical properties of intrinsic hydrogenated amorphous silicon films prepared by high density plasma chemical vapor deposition for solar cell applications

    Science.gov (United States)

    Chen, Huai-Yi; Lee, Yao-Jen; Chang, Chien-Pin; Koo, Horng-Show; Lai, Chiung-Hui

    2013-01-01

    P-i-n single-junction hydrogenated amorphous silicon (a-Si:H) thin film solar cells were successfully fabricated in this study on a glass substrate by high density plasma chemical vapor deposition (HDP-CVD) at low power of 50 W, low temperature of 200°C and various hydrogen dilution ratios (R). The open circuit voltage (Voc ), short circuit current density (Jsc ), fill factor (FF) and conversion efficiency (η) of the solar cell as well as the refractive index (n) and absorption coefficient (α) of the i-layer at 600 nm wavelength rise with increasing R until an abrupt drop at high hydrogen dilution, i.e. R > 0.95. However, the optical energy bandgap (Eg ) of the i-layer decreases with the R increase. Voc and α are inversely correlated with Eg . The hydrogen content affects the i-layer and p/i interface quality of the a-Si:H thin film solar cell with an optimal value of R = 0.95, which corresponds to solar cell conversion efficiency of 3.85%. The proposed a-Si:H thin film solar cell is expected to be improved in performance.

  15. Collision frequency of Lennard-Jones fluids at high densities by equilibrium molecular dynamics simulation

    International Nuclear Information System (INIS)

    Adebayo, G.A.; Anusionwu, B.C.; Njah, A.N.; Adeniran, O.J.; Mathew, B.; Sunmonu, R.S.

    2009-01-01

    Arising from the inability of theoretical calculations to give accurate descriptions of (shear) viscosity in rare gases at high densities, we investigated the likely cause of discrepancy between theory and experiments. Molecular Dynamics simulations were performed to calculate transport coefficients and collision frequency of rare gases at high densities and different temperatures using a Lennard-Jones modelled pair potential. The results, when compared with experiments show an underestimation of the viscosity calculated through the Green-Kubo formalism, but in agreement with some other calculations performed by other groups. In the present work the origin of the underestimation is considered. Analyses of the transport coefficients show a very high collision frequency which suggests an atom may spend much less time in the neighbourhood of the fields of force of another atom and that the distribution in the systems studied adjusts itself to a nearly Maxwellian type which resulted in a locally and temporarily slowly varying temperature. We show that the time spent in the fields of force is so small compared with relaxation time thereby leading to a possible reduction in local velocity auto-correlation between atoms. (author)

  16. Novel changes in discoidal high density lipoprotein morphology: a molecular dynamics study.

    Science.gov (United States)

    Catte, Andrea; Patterson, James C; Jones, Martin K; Jerome, W Gray; Bashtovyy, Denys; Su, Zhengchang; Gu, Feifei; Chen, Jianguo; Aliste, Marcela P; Harvey, Stephen C; Li, Ling; Weinstein, Gilbert; Segrest, Jere P

    2006-06-15

    ApoA-I is a uniquely flexible lipid-scavenging protein capable of incorporating phospholipids into stable particles. Here we report molecular dynamics simulations on a series of progressively smaller discoidal high density lipoprotein particles produced by incremental removal of palmitoyloleoylphosphatidylcholine via four different pathways. The starting model contained 160 palmitoyloleoylphosphatidylcholines and a belt of two antiparallel amphipathic helical lipid-associating domains of apolipoprotein (apo) A-I. The results are particularly compelling. After a few nanoseconds of molecular dynamics simulation, independent of the starting particle and method of size reduction, all simulated double belts of the four lipidated apoA-I particles have helical domains that impressively approximate the x-ray crystal structure of lipid-free apoA-I, particularly between residues 88 and 186. These results provide atomic resolution models for two of the particles produced by in vitro reconstitution of nascent high density lipoprotein particles. These particles, measuring 95 angstroms and 78 angstroms by nondenaturing gradient gel electrophoresis, correspond in composition and in size/shape (by negative stain electron microscopy) to the simulated particles with molar ratios of 100:2 and 50:2, respectively. The lipids of the 100:2 particle family form minimal surfaces at their monolayer-monolayer interface, whereas the 50:2 particle family displays a lipid pocket capable of binding a dynamic range of phospholipid molecules.

  17. StreamMap: Smooth Dynamic Visualization of High-Density Streaming Points.

    Science.gov (United States)

    Li, Chenhui; Baciu, George; Han, Yu

    2018-03-01

    Interactive visualization of streaming points for real-time scatterplots and linear blending of correlation patterns is increasingly becoming the dominant mode of visual analytics for both big data and streaming data from active sensors and broadcasting media. To better visualize and interact with inter-stream patterns, it is generally necessary to smooth out gaps or distortions in the streaming data. Previous approaches either animate the points directly or present a sampled static heat-map. We propose a new approach, called StreamMap, to smoothly blend high-density streaming points and create a visual flow that emphasizes the density pattern distributions. In essence, we present three new contributions for the visualization of high-density streaming points. The first contribution is a density-based method called super kernel density estimation that aggregates streaming points using an adaptive kernel to solve the overlapping problem. The second contribution is a robust density morphing algorithm that generates several smooth intermediate frames for a given pair of frames. The third contribution is a trend representation design that can help convey the flow directions of the streaming points. The experimental results on three datasets demonstrate the effectiveness of StreamMap when dynamic visualization and visual analysis of trend patterns on streaming points are required.

  18. Chemical influence on the hydro-mechanical behaviour of high-density bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Castellanos, E.; Romero, E.; Lioret, A. [Technical Univ. of Catalonia UPC, Barcelona (Spain); Musso, G. [Politecnico di Torino, Torino (Italy)

    2005-07-01

    In radioactive waste disposal schemes, during the operational period of clay barriers, solute transport an d thermal gradients may alter the solute concentration of pore water. These induced changes have important consequences on hydro-mechanical properties and microstructural alterations (mineral composition and pore size distribution changes) of the clay barrier. Chemically induced changes originated by different imbibition fluids and soil mineral compositions have been a subject with a long research tradition. These researches have been mainly focused on the behaviour of reconstituted soils starting from slurry and saturated wit h saline solutions at elevated concentrations, where hydro-mechanical changes (soil compressibility and water permeability changes) are clearly detected. In contrast, available information concerning the response of high-density clays subjected to chemically induced actions with a wide range of pore solution concentrations is very limited in spite of its practical relevance to environmental geotechnics. This situation has been caused, at least in part, by the difficulties in detecting important hydro-mechanical changes when clays with low water storage capacity have been used. Nevertheless, this paper will demonstrate that even in the case of high-density fabrics, considerable changes can be observed when high-activity clays (bentonites) are imbibed with different pore fluid compositions. (authors)

  19. Neutron star evolution and the structure of matter at high density

    International Nuclear Information System (INIS)

    Soyeur, Madeleine.

    1981-09-01

    The structure and properties of neutron stars are determined by the state of cold nuclear matter at high density. In order to investigate the behavior of matter inside neutron stars, observables sensitive to their internal structure have to be calculated and confronted to observations. The thermal radiation of neutron stars seems to be a good candidate to be such observable. It can be shown that the neutrino luminosity of neutron stars, responsible for their cooling in the early stages of their evolution is strongly dependent on possible phase transitions to superfluid nucleons, to pion condensation or to quark matter. The specific heat of matter is also not the same in the various phases expected at high density and is particularly sensitive to the nucleon superfluidity. At present, both the theoretical estimates and the observations of the thermal properties of neutron stars are still quite preliminary. In particular, large uncertainties due to possible reheating mechanisms and magnetic field effects make the theoretical interpretation of the steady radiation of pulsars quite difficult

  20. Alternative reproductive tactics and inverse size-assortment in a high-density fish spawning aggregation.

    Science.gov (United States)

    Karkarey, Rucha; Zambre, Amod; Isvaran, Kavita; Arthur, Rohan

    2017-02-28

    At high densities, terrestrial and marine species often employ alternate reproductive tactics (ARTs) to maximize reproductive benefits. We describe ARTs in a high-density and unfished spawning aggregation of the squaretail grouper (Plectropomus areolatus) in Lakshadweep, India. As previously reported for this species, territorial males engage in pair-courtship, which is associated with a pair-spawning tactic. Here, we document a previously unreported school-courtship tactic; where territorial males court multiple females in mid-water schools, which appears to culminate in a unique 'school-spawning' tactic. Courtship tactics were conditional on body size, local mate density and habitat, likely associated with changing trade-offs between potential mating opportunities and intra-sexual competition. Counter-intuitively, the aggregation showed a habitat-specific inverse size-assortment: large males courted small females on the reef slope while small males courted equal-sized or larger females on the shelf. These patterns remained stable across two years of observation at high, unfished densities. These unique density-dependent behaviours may disappear from this aggregation as overall densities decline due to increasing commercial fishing pressure, with potentially large consequences for demographics and fitness.