The high frequency flexural ultrasonic transducer for transmitting and receiving ultrasound in air

Flexural ultrasonic transducers are robust and low cost sensors that are typically used in industry for distance ranging, proximity sensing and flow measurement. The operating frequencies of currently available commercial flexural ultrasonic transducers are usually below 50 kHz. Higher operating frequencies would be particularly beneficial for measurement accuracy and detection sensitivity. In this paper, design principles of High Frequency Flexural Ultrasonic Transducers (HiFFUTs), guided by the classical plate theory and finite element analysis, are reported. The results show that the diameter of the piezoelectric disc element attached to the flexing plate of the HiFFUT has a significant influence on the transducer's resonant frequency, and that an optimal diameter for a HiFFUT transmitter alone is different from that for a pitch-catch ultrasonic system consisting of both a HiFFUT transmitter and a receiver. By adopting an optimal piezoelectric diameter, the HiFFUT pitch-catch system can produce an ultrasonic signal amplitude greater than that of a non-optimised system by an order of magnitude. The performance of a prototype HiFFUT is characterised through electrical impedance analysis, laser Doppler vibrometry, and pressure-field microphone measurement, before the performance of two new HiFFUTs in a pitch-catch configuration is compared with that of commercial transducers. The prototype HiFFUT can operate efficiently at a frequency of 102.1 kHz as either a transmitter or a receiver, with comparable output amplitude, wider bandwidth, and higher directivity than commercially available transducers of similar construction

Venting in the comparative study of flexural ultrasonic transducers to improve resilience at elevated environmental pressure levels

The classical form of a flexural ultrasonic transducer is a piezoelectric ceramic disc bonded to a circular metallic membrane. This ceramic induces vibration modes of the membrane for the generation and detection of ultrasound. The transducer has been popular for proximity sensing and metrology, particularly for industrial applications at ambient pressures around 1 bar. The classical flexural ultrasonic transducer is not designed for operation at elevated pressures, such as those associated with natural gas transportation or petrochemical processes. It is reliant on a rear seal which forms an internal air cavity, making the transducer susceptible to deformation through pressure imbalance. The application potential of the classical transducer is therefore severely limited. In this study, a venting strategy which balances the pressure between the internal transducer structure and the external environment is studied through experimental methods including electrical impedance analysis and pitch-catch ultrasound measurement. The vented transducer is compared with a commercial equivalent in air towards 90 bar. Venting is shown to be viable for a new generation of low cost and robust industrial ultrasonic transducers, suitable for operation at high environmental pressure levels

A METHOD AND SYSTEM FOR PROVIDING CONTACTLESS UPGRADE FOR LOYALTY CARDS

The present disclosure relates to a method and system for providing contactless upgrade for loyalty cards. The method includes creating a cryptographic paired relationship between a loyalty card associated with a user, a network device associated with a merchant and merchant store. In order to create the cryptographic pair, the method includes providing a Near Field Communication (NFC) stickers specific to each merchant. The NFC sticker may include login details to connect to a network of the merchant store. The user may download an application associated with the merchant in order to login to the network of merchant store. On following the login, the NFC sticker may be applied on the loyalty card. The loyalty card may then be used to open corresponding mobile application of the merchant in the mobile device in order to scan the NFC sticker on the loyalty card. On successful scanning, data from the NFC sticker is transmitted via the application to the network of the merchant store to verify user details and assign the details and login details to the merchant store. Thereafter, a notification request may be provided to the user on the application to join the network of the merchant store. Once the user accepts the request, the loyalty card is upgraded, and a confirmation is provided to the user. Thereafter, at any subsequent visit to the merchant store, the loyalty card may be used passively without utilising mobile phone details given the mobile phone or its connected wearable/IoT peers connect to the network of the merchant store (e.g. LAN) with the previously stored login details

METHOD, SYSTEM, AND COMPUTER PROGRAM PRODUCT FOR PROVIDING RECOMMENDATIONS

Provided is a method for providing at least one recommendation. The method may include receiving transaction data associated with a plurality of payment transactions from a plurality of merchants. Inventory data associated with a first merchant of the plurality of merchants may be received. Preference data associated with the first merchant of the plurality of merchants may be received. At least one recommendation for the first merchant may be determined based on the transaction data, the inventory data, and the preference data. The recommendation(s) may be transmitted to the first merchant. A system and computer program product are also disclosed

Memristor MOS Content Addressable Memory (MCAM): Hybrid Architecture for Future High Performance Search Engines

Large-capacity Content Addressable Memory (CAM) is a key element in a wide variety of applications. The inevitable complexities of scaling MOS transistors introduce a major challenge in the realization of such systems. Convergence of disparate technologies, which are compatible with CMOS processing, may allow extension of Moore's Law for a few more years. This paper provides a new approach towards the design and modeling of Memristor (Memory resistor) based Content Addressable Memory (MCAM) using a combination of memristor MOS devices to form the core of a memory/compare logic cell that forms the building block of the CAM architecture. The non-volatile characteristic and the nanoscale geometry together with compatibility of the memristor with CMOS processing technology increases the packing density, provides for new approaches towards power management through disabling CAM blocks without loss of stored data, reduces power dissipation, and has scope for speed improvement as the technology matures.Comment: 10 pages, 11 figure

Combining noise mapping and ventilation performance for non-domestic buildings in an urban area

Maximising the natural ventilation of a building can be beneficial in terms of comfort and reduced reliance on air-conditioning. However, in urban areas this can conflict with the need to reduce the ingress of external noise. In this paper a method is presented to quantify the interaction of building noise exposure with natural ventilation potential. Finite element models of ventilation aperture sound reduction index were used to determine façade sound insulation values for naturally ventilated buildings in two locations. Road traffic noise levels at the building façade were obtained from a calculated noise map of Manchester (UK). Window openings were adjusted in the thermal simulation package and modelled with mixed mode cooling ventilation strategies (both natural and mechanical). This enabled noise considerations to be quantified in terms of building ventilation and energy use for cooling at the whole building level. For a tolerated internal road noise ingress of 34 dB(A) cooling energy consumption for the example buildings in the quieter noise locations was found to decrease by 22%–45% compared to the noisier locations. Most importantly, the introduction of noise reduction measures equal to 10 dB(A) resulted in reductions in cooling energy consumption that varied from 28% to 45% of the original cooling energy consumption. This study illustrates the importance of an integrated approach to both noise exposure and ventilation performance in urban buildings

Dynamic nonlinearity in piezoelectric flexural ultrasonic transducers

Recent studies of the electro-mechanical behavior of flexural ultrasonic transducers have shown that their response can be considered as three distinct characteristic regions, the first building towards a steady state, followed by oscillation at the driving frequency in the steady state, before an exponential decay from the steady state at the transducer's dominant resonance frequency, once the driving force is removed. Despite the widespread industrial use of these transducers as ultrasonic proximity sensors, there is little published information on their vibration characteristics under different operating conditions. Flexual transducers are composed of a piezoelectric ceramic disc bonded to the inner surface of a metallic cap, the membrane of which bends in response to the high-frequency ceramic vibrations of the ceramic. Piezoelectric devices can be subject to nonlinear behavior, but there is no reported detail of the nonlinearity in flexural transducers. Experimental investigation through laser Doppler vibrometry shows strong nonlinearity in the vibration response, where resonance frequency reduces with increasing vibration amplitude

Where is the Line? The Effect of Narrowed Scope of Discontinued Operations on Earnings Quality and Analysts’ Forecasts

In the past decades, the U.S. accounting standards have been trending toward more narrowed scope for the “below-the-line” items. This study examines whether the quality of “above-the-line” (or core) earnings and analysts’ forecasts is affected by the recent major rule change in this regard (i.e., ASU2014-8), which imposes much more stringent criteria for classifying dispositions as below-the-line items (i.e., discontinued operations). Using data surrounding this rule change, we find that the frequency of reported discontinued operations significantly reduces after the change, suggesting underlying dispositions being buried in the core earnings. More importantly, we find that the persistence and response coefficient of core earnings significantly reduce and that analysts’ forecast error and dispersion increase. Thus, the narrowed scope of below-the-line items required by ASU 2014-8 introduces significant noise to core earnings and increases information asymmetry and uncertainty between managers and financial analysts. Our findings should be of interest to accounting regulators, firm managers, analysts, and investors when they interpret both above- and below-the-line items

Nonlinearity in the dynamic response of flexural ultrasonic transducers

Recent studies of the electro-mechanical behavior of flexural ultrasonic transducers have shown that their response can be considered as three distinct characteristic regions, the first building towards a steady state, followed by oscillation at the driving frequency in the steady state, before an exponential decay from the steady state at the transducer's dominant resonance frequency, once the driving force is removed. Despite the widespread industrial use of these transducers as ultrasonic proximity sensors, there is little published information on their vibration characteristics under different operating conditions. Flexual transducers are composed of a piezoelectric ceramic disc bonded to the inner surface of a metallic cap, the membrane of which bends in response to the high-frequency ceramic vibrations of the ceramic. Piezoelectric devices can be subject to nonlinear behavior, but there is no reported detail of the nonlinearity in flexural transducers. Experimental investigation through laser Doppler vibrometry shows strong nonlinearity in the vibration response, where resonance frequency reduces with increasing vibration amplitude