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A novel hierarchical heterostructure based on ZnO/ $\gamma $ -Fe2O3 nanorods decorated with nanoparticles has been synthesized via simple solvothermal approach followed by calcination at an elevated temperature. Considering the unique properties of both ZnO and $\gamma $ -Fe2O3 toward the sensing of reducing gases, the concept of forming a heterostructure between them has been conceived. The crystallinity, morphological structure, and defect states of nanostructures based on ZnO/ $\gamma $ -Fe2O3 composites were investigated by XRD, FESEM, TEM, and PL spectroscopy analysis. A flowerlike morphology was revealed with the coexistence of both ZnO and $\gamma $ -Fe2O3 leading to the formation of the heterostructure. The as-prepared ZnO/ $\gamma $ -Fe2O3 sensors display apparently enhanced sensing characteristics, including higher sensing response, quick response with recovery, and better selectivity toward acetone gas as compared to bare ZnO nanorods. The sensor showed selective detection of acetone among six VOC’s at an optimum temperature of 300°C. The response and recovery time of the sensor was found to be 12.5 and 26.9 s, respectively, compared to 51 and 80 s for bare ZnO nanorods, when exposed to 60-ppm concentration of acetone. This ultrafast and selective detection of acetone by ZnO/ $\gamma $ -Fe2O3 heterostructure shows potential to develop future commercial acetone sensor. [ABSTRACT FROM AUTHOR]

This paper describes the synthesis of novel semiconducting material bovine serum albumin molybdenum disulfide (BSA-MoS2) composite (BMC) for chemical sensing. It has been investigated that layer-dependent material (BMC) has a strong potential to fabricate the electronic devices for sensing. Transmission electron microscopy and UV-visible spectroscopy were used to characterize the synthesized BSA-MoS2 composite, prior to device fabrication. The device was fabricated using a simple drop-casting technique at room temperature. Liquid exfoliation technique was utilized to exfoliate the MoS2 to prepare the bio-composite material. The conductance of the device varies with humidity, which is utilized as the main operating principle. The device exhibits ~1 s response time and ~3 s recovery time, keeping the operating voltage fixed at 0.5 V for ultra-low power sensor device application. [ABSTRACT FROM AUTHOR]

This paper proposes a new spur reducing architecture of phase-locked loop-based frequency synthesizer. With an array of switched capacitors and a delay locked loop, the charge coming from its charge pump is evenly transferred to its loop filter at a fixed number of equi-spaced time intervals. It results in the reduction of fundamental and higher-order harmonics of the reference spur. The proposed architecture has been designed and fabricated in 180 nm CMOS technology. Randomization scheme has also been incorporated in the proposed architecture to reduce the effect of implementation mismatch on the output spur. Measured result shows about 5.47 dB reduction of fundamental spur compared to that of the conventional architecture with almost no degradation of noise performance. [ABSTRACT FROM AUTHOR]