1,729,589 research outputs found
Chroococcidiopsis sp. PCC 8201
No full textProtein sequences of Chroococcidiopsis sp. PCC 8201. Annotated with Prokka (http://www.vicbioinformatics.com/software.prokka.shtml)
Electrochemical Properties of Layered NaxNix 2Mn1 x 2O2 0.5 amp; 8201; amp; 8804; amp; 8201;x amp; 8201; amp; 8804; amp; 8201;1.1 with P3 Structure as Cathode for Sodium Ion Batteries
Get PDFThe Na properties of Ni and Mn containing layered oxides of the type Na x Ni x 2Mn1 amp; 8722;x 2O2 are explored between Na contents of 0.5 amp; 8804;x amp; 8804;1.1. Charge balance is maintained by adjusting the Ni Mn ratio. X ray diffraction and scanning electron microscopy are used to characterize the structure and morphology. The primary phase for all as synthesized materials is P3, especially at Na contents below x amp; 8201; amp; 8804; amp; 8201;0.8. Samples with a Na content of x amp; 8201; amp; 8805; amp; 8201;0.9 lead to the formation of Na and Ni secondary phases. The Na storage properties are studied in half cells with two different voltage windows between 1.5 4.0 amp; 8201;V and 2.2 4.5 amp; 8201;V vs Na Na . Ni and Mn redox are active between 1.5 and 4.0 amp; 8201;V accompanying three voltage plateaus at 3.7, 3.0, and 2.1 amp; 8201;V, respectively. An additional high voltage plateau gt;4.0 amp; 8201;V is observed when increasing the cutoff voltage to 4.5 amp; 8201;V. The initial Na content has a strong influence on the discharge capacity which ranges from 90 amp; 8201;mAh amp; 8201;g amp; 8722;1 x amp; 8201; amp; 8201;1.1 to 210 amp; 8201;mAh amp; 8201;g amp; 8722;1 x amp; 8201; amp; 8201;0.6 . C rate tests up to 2C and cycle life over 150 cycles are discussed. Overall, the composition Na0.6Ni0.3Mn0.7O2 shows the most favorable properties with respect to capacity retention, rate capability, and initial Coulomb efficienc
Manufacturing technologies for ultrasonic transducers in the 40 kHz to 40 MHz frequency range
No full textS.297-306Ultraschallwandler werden zum Senden und Empfangen akustischer Wellen eingesetzt und bilden damit das Herzstück eines jeden Ultraschallprüfgeräts. Je nach Anwendung arbeiten sie in unterschiedlichen Frequenzbereichen. Ultraschallwandler mit niedrigen Arbeitsfrequenzen von 1 kHz bis 1 MHz werden insbesondere für Sonaranwendungen benötigt, wohingegen Hochfrequenz-Ultraschallwandler mit Arbeitsfrequenzen von mehr als 15 MHz für die hochauflösende Bildgebung im Rahmen biomedizinischer Untersuchungen und zerstörungsfreier Prüfverfahren interessant sind. Herkömmliche zerstörungsfreie Diagnose- und klinische Ultraschallbildgebungssysteme werden typischerweise mit Ultraschallwandlern, die bei Frequenzen zwischen 1 MHz und 10 MHz arbeiten, betrieben. Im Hinblick auf eine leistungsfähige Auslegung und kosteneffektive Fertigung müssen sowohl die verwendeten piezoelektrischen Komponenten als auch die Größe und innere Struktur solcher Wandler auf den Anwendungsfall zugeschnitten sein. Neben dem Ultraschallwandler, als aktives Element zur Umwandlung von elektrischer Energie in Schallenergie und umgekehrt, werden in einem Ultraschallprüfkopf weitere Komponenten wie Dämpfungskörper und Anpassschichten integriert um die Funktion an die jeweilige Messaufgabe anzupassen. Der Aufbau funktionsfähiger Ultraschallgeräte umfasst darüber hinaus die Ansteuer- und Auswerteelektronik sowie die Bildverarbeitung. Im vorliegenden Artikel werden verschiedene Fertigungstechnologien für Ultraschallwandler unterschiedlicher Frequenzbereiche vorgestellt, die von den Autoren in den vergangenen Jahren entwickelt wurden. 1-3-Piezokomposite auf der Basis von piezokeramischen Fasern können in nahezu jeder Dicke hergestellt werden, was Arbeitsfrequenzen entsprechender Ultraschallwandler zwischen 40 kHz und 8 MHz erlaubt. Das Soft-Mold-Verfahren ermöglicht die Herstellung von Hochfrequenz-Ultraschallwandlern mit Arbeitsfrequenzen von 5 MHz bis 40 MHz. Hochintegrierte Wandler können durch Siebdruck von Elektroden-, Piezokeramik- und Isolationsschichten auf mikroelektronischen Substraten hergestellt werden. Damit sind strukturierte Ultraschallwandler mit Arbeitsfrequenzen zwischen 5 MHz und 30 MHz möglich.Ultrasonic transducers are used for emitting and receiving of acoustic waves. According to the application field, working frequency of ultrasonic transducers needs to be tailored to a certain value. Low frequency ultrasonic transducers with working frequencies of 1 kHz to 1 MHz are especially interesting for sonar applications, whereas high frequency ultrasonic transducers with working frequencies higher than 15 MHz are favorable for high-resolution imaging in biomedical and non-destructive evaluation. Conventional non-destructive testing devices and clinical ultrasound imaging systems are typically operated at frequencies between 1 MHz and 10 MHz. Depending on the operational scenario, piezoelectric material as well as size and inner structure of the ultrasonic transducer has to be customized. We here report on different manufacturing technologies for ultrasonic transducers in a broad frequency range. 1-3 piezocomposites based on piezoceramic fibers can be fabricated in almost every thickness allowing for transducer frequencies between 40 kHz and 8 MHz. The soft mold process enables the fabrication of high frequency ultrasonic transducers with potential frequencies of 5 MHz up to 40 MHz. Highly integrated ultrasonic transducers can be prepared by screen-printing a sequence of electrode, piezoceramic, and isolation layers on microelectronic substrates. By this, patterned ultrasonic transducers with working frequencies between 5 MHz and 30 MHz are possible.86Nr.
Mechanism of gas separation through amorphous silicon oxycarbide membranes 
No full textS.721-727Polymer-derived amorphous silicon oxycarbide (SiOC) ceramics are designed for hydrogen separation at high temperatures. To form amorphous SiOC top-coating with the thickness of about 300 nm, tubular porous g-Al2O3/a-Al2O3 substrates with gradient porosity are threefold coated by vinyl-functionalized polysiloxane and pyrolyzed at 700 °C under argon. N2-physisorption measurement confirms formation of microporous material with a specific surface area of about 400 m2 g-1. Single gas permeance characterization of the SiOC membrane at 300 °C reveals H2/CO2 and H2/SF6 ideal permselectivities of about 10 and 320, respectively. The experimental gas permeance data are modeled using solid-state diffusion (for He and H2) and gas translational diffusion (for CO2 and SF6) mechanisms.18Nr.
Search for a Heavy Particle Decaying to a Top Quark and a Light Quark in pp̅ Collisions at √s=1.96  TeV
No full textWe present a search for a new heavy particle X produced in association with a top quark, pp̅ →t(X→t̅ q) or pp̅ →t̅ (X̅ →tq̅ ), where q stands for up quarks and down quarks. Such a particle may explain the recent anomalous measurements of top-quark forward-backward asymmetry. If the light-flavor quark (q) is reconstructed as a jet (j), this gives a t̅ +j or t+j resonance in tt̅ +jet events, a previously unexplored experimental signature. In a sample of events with exactly one lepton, missing transverse momentum and at least five jets, corresponding to an integrated luminosity of 8.7  fb-1 collected by the CDF II detector, we find the data to be consistent with the standard model. We set cross-section upper limits on the production (pp̅ →Xt or X̅ t̅ ) at 95% confidence level from 0.61 pb to 0.02 pb for X masses ranging from 200  GeV/c2 to 800  GeV/c2, respectively
Polymer enabled 100 Gbaud connectivity for datacom applications
No full textS.13-21Polymers hold the promise for ultra-fast modulation of optical signals due to their potential for ultra-fast electro-optic (EO) response and high EO coefficient. In this work, we present the basic structure and properties of an efficient EO material system, and we summarize the efforts made within the project ICT-POLYSYS for the development of high-speed transmitters based on this system. More specifically, we describe successful efforts for the monolithic integration of multi-mode interference (MMI) couplers and Bragg-gratings (BGs) along with Mach-Zehnder modulators (MZMs) on this platform, and for the hybrid integration of InP active elements in the form of laser diodes (LDs) and gain chips (GCs). Using these integration techniques and the combination of the hybrid optical chips with ultra-fast indium phosphide double heterojunction bipolar transistor (InP-DHBT) electronics, we develop and fully package a single 100 Gb/s transmitter and a 2×100 Gb/s transmitter that can support serial operation at this rate with conventional non-return-to-zero on-off-keying (NRZ-OOK) modulation format. We also present the experimental evaluation of the devices, validating the efficiency of the monolithic and hybrid integration concepts and confirming the potential of this technology for single-lane 100 Gb/s optical connectivity in data-center network environments. Results from transmission experiments to this end include the achievement of BER close to 6×10−9 in B2B configuration, the achievement of BER lower than 10−7 for propagation over standard single-mode fiber (SSMF) with total length up to 1000 m, and the achievement of BER at the level of 10−5 after 1625 m of SSMF. Finally, plans for the use of the EO polymer system in a more complex hybrid integration platform for high-flexibility/high-capacity transmitters are also outlined.36
A double-stream Xe:He jet plasma emission in the vicinity of 6.7 nm
No full textArt.221101, 5 S.We present the results of investigations of extreme ultraviolet (EUV) light emission in the range from 5 to 10 nm. The light source was a pulsed ""double-stream"" Xe:He gas jet target irradiated by a laser beam with a power density of ∼1011 W/cm2. The radiation spectra were measured with a Czerny-Turner monochromator with a plane diffraction grating. The conversion efficiency of the laser energy into EUV radiation caused by Xe+14EL+16 ion emission in the range of 6-8 nm was measured using a calibrated power meter. The conversion efficiency of the laser radiation into EUV in the vicinity of 6.7 nm was (2.17 ± 0.13)% in a 1 nm spectral band. In the spectral band of the real optical system (0.7% for La/B multilayer mirrors) emitted into the half-space, it was (0.1 ± 0.006)%. The results of this study provide an impetus for further research on laser plasma sources for maskless EUV lithography at a wavelength of 6.7 nm.112Nr.2
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
[Zelnicker, Incorporated, Engine Drawing Card, Sketch No. 8201]
No full textThis engine drawing card was created for Zelnicker, Incorporated, Class 4-30C. Section J-4C. Sketch 8201. Copy Spec. 32D7
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