Compact WLAN disc antennas

A novel conical beam patch antenna design, suitable for local area network applications, uses a central cylindrical connection from the disc to ground to achieve a large reduction in resonant size. Results on efficiency, bandwidth, and pattern are reported for several prototypes.     

A 2.4-GHz CMOS transceiver for Bluetooth

A fully integrated CMOS transceiver tuned to 2.4 GHz consumes 46 mA in receive mode and 47 mA in transmit mode from a 2.7-V supply. It includes all the receive and transmit building blocks, such as frequency synthesizer, voltage-controlled oscillator (VCO), power amplifier, and demodulator. The receiver uses a low-IF architecture for higher level of integration and lower power consumption. It achieves a sensitivity of -82 dBm at 0.1% BER, and a third-order input intercept point (IIP3) of -7 dBm. The direct-conversion transmitter delivers a GFSK modulated spectrum at a nominal output power of 4 dBm. The on-chip voltage controlled oscillator has a close-in phase-noise of -120 dBc/Hz at 3-MHz offset     

Physical and geochemical properties of crude oils in relation to their source rocks,Alif field,Marib Sub-basin,Yemen

Physical and geochemical properties were performed on three crude oils from Alif-01 well in the Marib sub-basin. The analyzed samples comprise medium specific gravity (37^° API), reflecting mature source rocks. The thermal maturity of the analyzed oils is also indicated from the high content of aliphatic hydrocarbons (HC). The compositions of HC further suggest that analyzed oils belong to paraffinic oils. The n-alkane and isoprenoid distributions reveal that the analyzed oils are derived from marine source rock, containing mixed organic matter, with some terrestrial input and deposited under relatively reducing conditions. The features of the analyzed oils are consistent with the Madbi source rock characteristics in the basin.     

Injection-locked passively Q-switched lasers

The time-dependent behavior of an injection locked single-mode passivelyQ-switched laser may be described by three coupled first-order rate equations relating the laser gain, the absorber loss, and the optical power density. Injection locking results in a substantial increase in the mean output power and the output pulse energy and higher pulsation rate than when freely running. Stability analysis allows the determination of the maximum injected power that allows pulsations.     

On the Electromagnetic Interference Fringes Method in Geophysical Prospecting Applications

The method of electromagnetic interference fringes for the prospecting of conductive subsurfaces inside the earth is reviewed. The fields radiated by an electrically small horizontal loop situated on the earth's surface are derived and expressed in terms of different interfering wave components. The variable distance interference fringes (VDIF) method and the variable frequency interference (VFIF) method of prospecting are considered, and an interpretation procedure using the data obtained from both methods is suggested.     

Combined effect of gamma-irradiation and conventional cooking onAeromonas hydrophila in meatball

Irradiation combined with a conventional cooking procedure was applied to meatball and the effects on bacterial load and inoculatedAeromonas hydrophila were determined. Meatball samples were irradiated by using a⁶⁰Co source at the dose levels of 0, 0.30,0.75,1.50,2.50 kGy and cold stored at 4±1°C for 7 days. Bacterial load and the count ofA. hydrophila decreased when the irradiation dose level increased. A minimum inhibition effect was found at the dose of 0.30 kGy. Irradiation in combination with a conventional cooking procedure was found to be more effective in reducingA. hydrophila and the bacterial load in meatball. This study indicated that a dose of 0.75 kGy was sufficient to destroy approximately 10⁴ cfu/g ofA. hydrophila in meatball.     

Characterizing multi‐hop localization for Internet of things

Deployments over large geographical areas in the Internet of Things (IoT) pose a major challenge for single‐hop localization techniques, giving rise to applications of multi‐hop localizations. And while many proposals have been made on implementations for multi‐hop localization, a close understanding of its characteristics is yet to be established. Such an understanding is necessary, and is inevitable in extending the reliability of location based services in IoT. In this paper, we study the characteristics of multi‐hop localization and propose a new solution to enhance the performance of multi‐hop localization techniques. We first examine popular assumptions made in simulating multi‐hop localization techniques, and offer rectifications facilitating more realistic simulation models. We identify the introduced errors to follow the Gaussian distribution, and the estimated distance follows the Rayleigh distribution. We next use our simulation model to characterize the effect of the number of hops on localization in both dense and sparse deployments. We find that, contrary to common belief, it is better to use long hops in sparse deployments, while short hops are better in dense deployments – despite the traffic overhead. Finally, we propose a new solution that decreases and manages the overhead generated during the localization process. Copyright © 2016 John Wiley & Sons, Ltd.     

Hybrid wavelet measurement matrices for improving compressive imaging

Compressive sensing principle claims that a compressible signal can be recovered from a small number of random linear measurements. However, the design of efficient measurement basis in compressive imaging remains as a challenging problem. In this paper, a new set of hybrid wavelet measurement matrices is proposed to improve the quality of the compressive imaging, increase the compression ratio and reduce the processing time. The performance of these hybrid wavelet matrices for image modeling and reconstruction is evaluated and compared with other traditional measurement matrices such as the random measurement matrices, Walsh and DCT matrices. The compressive imaging approach chosen in this study is the block compressive sensing with smoothed projected Landweber reconstruction technique. The simulation results indicate that the imaging performance of the proposed hybrid wavelet measurement matrices is approximately 2–3 dB better than that obtained using Gaussian matrix especially at higher compression ratios.     

Quantum‐Tunneling Metal‐Insulator‐Metal Diodes Made by Rapid Atmospheric Pressure Chemical Vapor Deposition

A quantum‐tunneling metal‐insulator‐metal (MIM) diode is fabricated by atmospheric pressure chemical vapor deposition (AP‐CVD) for the first time. This scalable method is used to produce MIM diodes with high‐quality, pinhole‐free Al₂O₃ films more rapidly than by conventional vacuum‐based approaches. This work demonstrates that clean room fabrication is not a prerequisite for quantum‐enabled devices. In fact, the MIM diodes fabricated by AP‐CVD show a lower effective barrier height (2.20 eV) at the electrode–insulator interface than those fabricated by conventional plasma‐enhanced atomic layer deposition (2.80 eV), resulting in a lower turn on voltage of 1.4 V, lower zero‐bias resistance, and better asymmetry of 107.