Ultra-thin graphene edges at the nanowire tips: a cascade cold cathode with two-stage field amplification

A multistage field emitter based on graphene-linked ZnO nanowire array is realized by means of spin-coating a graphene dispersion (reduced graphene oxide) over a nanostructured platform followed by plasma modification. Spin-coating leads to interlinking of graphene sheets between the neighboring nanowires whereas plasma etching in the subsequent step generates numerous ultra-sharp graphene edges at the nanowire tips. The inherent tendency of graphene to lay flat over a plane substrate can easily be bypassed through the currently presented nanostructure platform based technique. The turn-on and threshold field significantly downshifted compared to the individual components in the cascade emitter. Through the facile electron transfer from nanowires to graphene due to band bending at the ZnO-graphene interface together with multistage geometrical field enhancement at both the nanowire and graphene edges remain behind this enriched field emission from the composite cold cathode. This strategy will open up a new direction to integrate the functionalities of both the graphene array and several other inorganic nanostructure array for practical electronic devices.     

The effect of surface recombination on the frequency-dependentcharacteristics of an ion-implanted GaAs OPFET

The effect of modulation frequency and surface recombination on the characteristics of an ion-implanted GaAs OPFET is determined analytically. The drain-source current is found to decrease with the increase in both modulation frequency and trap center density. The current changes significantly with the trap center density only when the latter is greater than 10²⁰/m². The threshold voltage does not change appreciably with the modulation frequency as in a silicon OPFET. However, the increased in the trap center density causes V_T to increase in the enhancement device and decrease in the depletion device. Further, V_T increases under the normally ON condition and decreases under the normally OFF condition with an increase in the photon absorption coefficient in GaAs. Some anomalous behavior is observed for higher values of the absorption coefficient     

Trade-offs in the OTA-based analog filter design

Operational transconductance amplifiers (OTAs) are widely used in the design of electronically tunable circuits. However, electronic tunability ranges of the OTA based filters are restricted by the limited bandwidth of the transconductance gain of the OTA. Furthermore, stability conditions and the linearity of the OTA which depends on the control current restrict the tunability. In this paper, some trade-offs in the electronically tunable filters are investigated. In addition, the tunability ranges of some first and second order OTA-C and OTA-RC filters are comparatively examined. Moreover, an OTA-C all-pass filter circuit is presented. SPICE simulations are performed and stability analyses are given for both of the OTA-C and OTA-RC filters. Operation of the presented all-pass filter is verified experimentally.     

Very low-noise ENG amplifier system using CMOS technology.

In this paper, we describe the design and testing of a system for recording electroneurographic signals (ENG) from a multielectrode nerve cuff (MEC). This device, which is an extension of the conventional nerve signal recording cuff, enables ENG to be classified by action potential velocity. In addition to electrical measurements, we provide preliminary in vitro data obtained from frogs that demonstrate the validity of the technique for the first time. Since typical ENG signals are extremely small, on the order of 1 1 microV, very low-noise, high-gain amplifiers are required. The ten-channel system we describe was realized in a 0.8 microm CMOS technology and detailed measured results are presented. The overall gain is 10 000 and the total input-referred root mean square (rms) noise in a bandwidth 1 Hz-5 kHZ is 291 nV. The active area is 12 mm(2) and the power consumption is 24 mW from +/-2.5 V power supplies.     

Magnetic Behaviour of Granular GdMnO<Subscript>3</Subscript> Film

The present study deals with the investigation of magnetic properties along with morphological and microstructure analyses of a multiferroic GdMnO₃ film fabricated on Si(100) substrate by the pulsed laser deposition technique. Rutherford backscattering spectroscopic analysis suggests that the film is fabricated in the form of diffused layers having different stoichiometric proportions. Raman spectroscopy signifies that few modes present in the film are associated with MnO₆ octahedra and some extra peaks indicating the mixed phase formation in tuning with the Rutherford backscattering spectroscopy. Atomic force microscopy confirms the granular nature of the film. Field-cooled and zero-field-cooled thermal magnetization curves show irreversible behaviour extending well above room temperature, which is associated with spin disorder. The presence of Gd⁺³ state and Mn⁺³/Mn⁺⁴ mixed states in the uppermost layers of the film was confirmed by near-edge X-ray absorption fine structure. Subsequently, in association with these observations, the film is a weak ferromagnetic at 5 K and even at room temperature.     

Inclusion of poultry based food ingredients in the formulation of noodles and their effects on noodle quality characteristics

Incorporating exogenous proteins into food products is a better practice for improving nutritional attributes of food commodities. In the search for a way to improve the product and nutritional quality of noodles, this study was aimed to evaluate the impact of the incorporation of poultry based ingredients egg yolk powder (EYP) and chicken mincemeat (CMM) in noodles at different levels (5, 10 and 15%, w/w). The incorporated noodles were subjected to evaluation of the cooking, texture, colour, sensory and microstructure properties. The results showed that the incorporation of poultry based food ingredient types and amount influence the nutritional content of noodles. Simultaneously, poultry based ingredients incorporated noodles showed the acceptable firmness and colour charatertistics. Scanning electron micrograph of the incorporated noodles showed the gelatinized starch granules enveloped by protein matrix, and also indicating a better structure as compared to the control. The sensory profile of incorporated noodles was showed significant (p?≤?0.05) high overall quality. The result of this study showed that 10% (w/w) EYP and 15% (w/w) CMM incorporated noodles showed a better overall noodles quality attributes (texture, colour, sensory and microstructure). The results also provide ideas about the inclusion of the appropriate levels of poultry based ingredients (EYP and CMM) with a better sensory and nutritional profile. Therefore, this study may be useful in the food industry for the production of poultry based ingredients noodles with enhanced quality characteristics.     

MIMO Channel Capacity and Configuration Selection for Switched Parasitic Antennas

Multiple-input multiple-output (MIMO) systems offer significant enhancements in terms of their data rate and channel capacity compared to traditional systems. However, correlation degrades the system performance and imposes practical limits on the number of antennas that can be incorporated into portable wireless devices. The use of switched parasitic antennas (SPAs) is a possible solution, especially where it is difficult to obtain sufficient signal decorrelation by conventional means. The covariance matrix represents the correlation present in the propagation channel, and has significant impact on the MIMO channel capacity. The results of this work demonstrate a significant improvement in the MIMO channel capacity by using SPA with the knowledge of the covariance matrix for all pattern configurations. By employing the “water-pouring algorithm” to modify the covariance matrix, the channel capacity is significantly improved compared to traditional systems, which spread transmit power uniformly across all the antennas. A condition number is also proposed as a selection metric to select the optimal pattern configuration for MIMO-SPAs.     

Influence of Grain Boundary Complexion on Deformation Mechanism of High Temperature Bending Creep Process of Cu Bicrystal

Despite of substantial advancement, the effect of grain boundary (GB) complexions on high temperature creep deformation process has not been fully understood. In this paper, we have studied the high temperature bending creep deformation of copper bicrystal with various GB complexions under different loads using molecular dynamics simulation. It has been found that specimen with normal kite GB complexion have better creep resistance properties when subjected to comparatively lower applied load. In case of monolayer Zr segregation, a drastic decrease in creep strength as well as creep plasticity is observed due to inhibition of GB migration. On the other hand, deviation between creep properties for specimen with split-kite GB complexion and split-kite bilayer Zr segregation GB complexion is minimal. Enhanced creep plasticity is observed in case of split-kite bilayer Zr segregation GB complexion, which is due to formation of interpenetrating icosahedral clusters in the necking region. Fracture in specimen with monolayer Zr segregation GB complexion has occurred by means of slip phenomenon at lower deformation load whereas amorphization and necking is observed at higher deformation load. In case of specimen with bilayer Zr segregation GB complexion, it is found that fracture has occurred through amorphization and necking at all deformation loads due to higher GB thickness.     

Frame selection for OCR from video stream of book flipping

Multimedia Tools and Applications - Optical Character Recognition (OCR) in video stream of flipping pages is a challenging task because flipping at random speed causes difficulties in identifying...     

Image retrieval based on non-uniform bins of color histogram and dual tree complex wavelet transform

Multimedia Tools and Applications - Traditional Content-Based Image Retrieval (CBIR) systems were developed for retrieving similar kinds of images from a whole image database based on the given...