Branched nanowire (NW) heterostructures have recently been attracted considerable attention for solar water splitting and clean hydrogen production due to their unique properties such as nanoscale integration of diffe...
Branched nanowire (NW) heterostructures have recently been attracted considerable attention for solar water splitting and clean hydrogen production due to their unique properties such as nanoscale integration of different functional materials, greatly enhanced junction and surface area, enhanced gas evolution efficiency, broadband light absorption, etc. Moreover, branched NWs can be fabricated using facile and scalable fabrication methods such as hydrothermal or solvothermal growth methods. In this presentation, we show branched NWs of different compositions for core (or trunk) and branch NWs which were fabricated with facile and low-cost synthesis methods using cheap, non-toxic, and earth abundant materials including Si, CuO, Cu2O, ZnO, TiO2, and Fe2O3. The branched NW structures and the heterostructures' interfaces are investigated in detail using different characterization techniques such as SEM/HRSEM, TEM/HRTEM, STEM/HRSETM, etc. The photoelectrochemical (PEC) performances including photocurrent turn-on potential, photocurrent, solar conversion efficiency, and incident photon-to-current efficiency (IPCE) are studied systematically and optimized, based on different core and branch NW dimensions, for each specific branched NW heterostructure to provide efficient water splitting in a neutral medium. The electrode stability of different branched NWs is also investigated and long-term stability of over one day or several hours using a thin passivation layer or robust branched NWs are presented. The achieved results pave the way for accomplishing spontaneous overall solar water splitting for clean, efficient, cost-effective and durable solar hydrogen generation at large scales.
DC faults may cause severe disruptions in continuity of service to vital loads in a shipboard integrated power system, hence detection, isolation, and protection against such faults must be incorporated in both medium...
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Nematic and cholesteric liquid crystals are three-dimensional fluids that possess long-range orientational ordering and can support both topological defects and chiral superstructures. Implications of this ordering re...
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Nematic and cholesteric liquid crystals are three-dimensional fluids that possess long-range orientational ordering and can support both topological defects and chiral superstructures. Implications of this ordering remain unexplored even for simple dynamic processes such as the ones found in so-called “fall experiments,” or motion of a spherical inclusion under the effects of gravity. Here we show that elastic and surface anchoring interactions prompt periodic dynamics of colloidal microparticles in confined cholesterics when gravity acts along the helical axis. We explore elastic interactions between colloidal microparticles and confining surfaces as well as with an aligned ground-state helical structure of cholesterics for different sizes of spheres relative to the cholesteric pitch, demonstrating unexpected departures from Stokes-like behavior at very low Reynolds numbers. We characterize metastable localization of microspheres under the effects of elastic and surface anchoring periodic potential landscapes seen by moving spheres, demonstrating the important roles played by anchoring memory, confinement, and topological defect transformation. These experimental findings are consistent with the results of numerical modeling performed through minimizing the total free energy due to colloidal inclusions at different locations along the helical axis and with respect to the confining substrates. A potential application emerging from this work is colloidal sorting based on particle shapes and sizes.
This paper presents the design and implementation of highly-miniaturized, low-power CMOS signal conditioning schemes intended for use in a totally implantable biomedical sensor platform. Due to the thrust for the deve...
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This paper presents the design and implementation of highly-miniaturized, low-power CMOS signal conditioning schemes intended for use in a totally implantable biomedical sensor platform. Due to the thrust for the development implantable biomedical sensing systems for health management and disease prevention, there exists a need for signal processing schemes which occupy very little on-chip real estate and consume negligible amounts of power. In light of this, this paper presents both a CMOS current-to-frequency converter and voltage-to-frequency converter which have been designed primarily for use in implantable biosensing platforms and applications. Such designs can be implemented in stand-alone single sensor designs, or in tandem to create multi-analyte architectures. The versatility of employing current-to-frequency as well as voltage-to-frequency signal transduction schemes presents an avenue for the integration with any electrochemical sensing element which has been fabricated in an amperometric or voltammetric fashion. Furthermore, we demonstrate the efficacy of both these circuit designs by integrating them together with high performance electrochemical implantable glucose and pH sensors. The low power consumption and miniature size of the amperometric and voltammetric signal processing units (0.25 mm 2 and 18 μW / 0.045 mm 2 and 122 μW, respectively) presents an ideal design for signal processing in implantable continuous metabolic monitoring devices.
For an automatic chromosome classification, band resolution information is required in order to perform diagnosis on numerical and structural abnormalities. Metaphases with low band resolution are normal used for nume...
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For an automatic chromosome classification, band resolution information is required in order to perform diagnosis on numerical and structural abnormalities. Metaphases with low band resolution are normal used for numerical abnormality analysis while metaphases with high band resolution are used for structural abnormality analysis. In our work, we classify metaphases into low and high band resolution groups using chromosome shape. This band classification task can automatically perform without human intervention leading to faster the diagnosis process. The results showed that chromosome shape information is able to classify metaphases into low and high band resolution groups with the accuracy of 73.08% and 95.24%, respectively.
In this study, a single-input multiple-outputs current-mode analog biquadratic filter, based on current differencing transconducatance amplifier (CDTA) is presented. The proposed filter uses two CDTAs, one resistor an...
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ISBN:
(纸本)9781467355797
In this study, a single-input multiple-outputs current-mode analog biquadratic filter, based on current differencing transconducatance amplifier (CDTA) is presented. The proposed filter uses two CDTAs, one resistor and two grounded capacitors, which is well suited for integrated circuit implementation. The circuit simultaneously gives 3 standard transfer functions, namely, lowpass, highpass and bandpass filters with independent control of quality factor and pole frequency by electronic method. By summing of IHP and ILP, the notch filter can be also achieved. Moreover, the circuit possesses low input and high output impedance which would be an ideal choice for current-mode cascading. The PSPICE simulation results are included verifying the workability of the proposed filter. The given results agree well with the theoretical anticipation.
This paper investigate the impact of primary transceivers on the outage performance of a dual-hop decode-and-forward (DF) spectrum sharing relay system with multiple secondary user (SU) destinations in Nakagami-m fadi...
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This paper investigate the impact of primary transceivers on the outage performance of a dual-hop decode-and-forward (DF) spectrum sharing relay system with multiple secondary user (SU) destinations in Nakagami-m fading channels. To doing so, we derive new exact and asymptotic closed-form expressions for the outage probability of spectrum sharing relay systems employing the opportunistic scheduling algorithm, which readily enable us to characterize the impact of various key system parameters on the outage performance of the system. Monte Carlo simulation results are provided to verify the theoretical analysis and evaluate the effects of channel fading severity, SU relay placement, and number of SU destinations. The finding of this paper suggests that the interference temperature constraint results in the outage saturation phenomenon and zero diversity gain of spectrum sharing relay systems.
This paper presents the design and fabrication of a highly-miniaturized system for continuous glucose monitoring which holds great promise for patients inflicted with diabetes mellitus. To achieve the realization of a...
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Ochratoxin-A[7-(L-β-phenylalanylcarbonyl)-carboxyl-5-chloro-8-hydroxy-3,4-dihydro-3R-methyl-isocumarin, OTA] is a common food contaminant mycotoxin that enters the human body through the consumption of improperly sto...
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Ochratoxin-A[7-(L-β-phenylalanylcarbonyl)-carboxyl-5-chloro-8-hydroxy-3,4-dihydro-3R-methyl-isocumarin, OTA] is a common food contaminant mycotoxin that enters the human body through the consumption of improperly stored food products. Upon ingestion, it leads to immuno-suppression and immuno-toxicity. OTA has been known to produce nephrotoxic, teratogenic, and carcinogenic activity (via oxidative DNA damage) in several species. This review introduces potentials of electrochemical biosensor to provide breakthroughs in OTA detection through improved selectivity and sensitivity and also the current approaches for detecting OTA in food products.
Cell selection in current LTE-Advanced depend on reference signal received power or reference signal received quality which results to low user association probability. Therefore, we propose an aggregate objective cel...
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ISBN:
(纸本)9781479906963
Cell selection in current LTE-Advanced depend on reference signal received power or reference signal received quality which results to low user association probability. Therefore, we propose an aggregate objective cell selection technique based on enhanced inter-cell interference coordination technique developed by 3GPP in Rel-10 known as almost blank subframe. We also adopt the use of cell range expansion technique as means to encourage offloading. Cell range expansion was introduced in LTE-advanced, it encourages user equipment to select a small cell with a weakest signal as thier serving cell by adding a positive bias in cell selection process. Simulation shows that the proposed scheme results to high user association probability, while giving superior performance in average throughput compared to conventional single objective base cell selection for cell range expansion.
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