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Alexander M Kaizer, Joseph S Koopmeiners, Brian P Hobbs
Bayesian hierarchical models produce shrinkage estimators that can be used as the basis for integrating supplementary data into the analysis of a primary data source. Established approaches should be considered limited, however, because posterior estimation either requires prespecification of a shrinkage weight for each source or relies on the data to inform a single parameter, which determines the extent of influence or shrinkage from all sources, risking considerable bias or minimal borrowing. We introduce multisource exchangeability models (MEMs), a general Bayesian approach for integrating multiple, potentially non-exchangeable, supplemental data sources into the analysis of a primary data source...
July 6, 2017: Biostatistics
Haifeng Xing, Bo Hou, Zhihui Lin, Meifeng Guo
MEMS (Micro Electro Mechanical System) gyroscopes have been widely applied to various fields, but MEMS gyroscope random drift has nonlinear and non-stationary characteristics. It has attracted much attention to model and compensate the random drift because it can improve the precision of inertial devices. This paper has proposed to use wavelet filtering to reduce noise in the original data of MEMS gyroscopes, then reconstruct the random drift data with PSR (phase space reconstruction), and establish the model for the reconstructed data by LSSVM (least squares support vector machine), of which the parameters were optimized using CPSO (chaotic particle swarm optimization)...
October 13, 2017: Sensors
V K Sharma, S S Kundu, C Datt, S Prusty, M Kumar, U B Sontakke
This study was conducted to evaluate the utilisation of the residual feed intake (RFI) as a feed efficiency selection tool and its relationship with methane emissions. Eighteen Murrah buffalo (Bubalus bubalis) heifers were fed ad libitum with total mixed ration (TMR) for 120 days. Based on linear regression models involving dry matter intake (DMI), average daily gain (ADG) and mid-test metabolic body size (MBW(0.75) ), heifers were assigned into low and high RFI groups. The RFI varied from -0.09 to +0.12 kg DM/day with average RFI of -0...
October 13, 2017: Journal of Animal Physiology and Animal Nutrition
Xukai Ding, Jia Jia, Yang Gao, Hongsheng Li
This paper presents a theoretical analysis of mechanical and electrical noise in the sense channel of micro-electromechanical systems (MEMS) vibratory gyroscopes. Closed-form expressions for the power spectral density (PSD) of the noise equivalent rate (NER) of gyroscopes in the open-loop and the force-rebalance operations are derived by using an averaged PSD model and an equivalent transfer function. The obtained expressions are verified through numerical simulations, demonstrating close agreements between the analytic and the numerical models...
October 11, 2017: Sensors
Vittorio M N Passaro, Antonello Cuccovillo, Lorenzo Vaiani, Martino De Carlo, Carlo Edoardo Campanella
This paper is an overview of current gyroscopes and their roles based on their applications. The considered gyroscopes include mechanical gyroscopes and optical gyroscopes at macro- and micro-scale. Particularly, gyroscope technologies commercially available, such as Mechanical Gyroscopes, silicon MEMS Gyroscopes, Ring Laser Gyroscopes (RLGs) and Fiber-Optic Gyroscopes (FOGs), are discussed. The main features of these gyroscopes and their technologies are linked to their performance.
October 7, 2017: Sensors
T Larsen, J C Doll, F Loizeau, N Hosseini, A W Peng, G Fantner, A J Ricci, B L Pruitt
Electrothermal actuators have many advantages compared to other actuators used in Micro-Electro-Mechanical Systems (MEMS). They are simple to design, easy to fabricate and provide large displacements at low voltages. Low voltages enable less stringent passivation requirements for operation in liquid. Despite these advantages, thermal actuation is typically limited to a few kHz bandwidth when using step inputs due to its intrinsic thermal time constant. However, the use of pre-shaped input signals offers a route for reducing the rise time of these actuators by orders of magnitude...
2017: Journal of Micromechanics and Microengineering: Structures, Devices, and Systems
Tadas Kartanas, Victor Ostanin, Pavan Kumar Challa, Ronan Daly, Jerome Charmet, Tuomas P J Knowles
Microelectromechanical systems (MEMS) have enabled the development of a new generation of sensor platforms. Acoustic sensor operation in liquid, the native environment of biomolecules, causes, however, significant degradation of sensing performance due to viscous drag and relies on the availability of capture molecules to bind analytes of interest to the sensor surface. Here we describe a strategy to interface MEMS sensors with microfluidic platforms through an aerosol spray. Our sensing platform comprises a microfluidic spray nozzle and a micro-cantilever array operated in dynamic mode within a closed loop oscillator...
October 6, 2017: Analytical Chemistry
Onur Tokel, Ahmet Turnali, Ghaith Makey, Parviz Elahi, Tahir Çolakoğlu, Emre Ergeçen, Özgün Yavuz, René Hübner, Mona Zolfaghari Borra, Ihor Pavlov, Alpan Bek, Raşit Turan, Denizhan Koray Kesim, Serhat Tozburun, Serim Ilday, F Ömer Ilday
Silicon is an excellent material for microelectronics and integrated photonics1-3 with untapped potential for mid-IR optics4. Despite broad recognition of the importance of the third dimension5,6, current lithography methods do not allow fabrication of photonic devices and functional microelements directly inside silicon chips. Even relatively simple curved geometries cannot be realised with techniques like reactive ion etching. Embedded optical elements, like in glass7, electronic devices, and better electronic-photonic integration are lacking8...
October 2017: Nature Photonics
R G Gomes, C B Silva, S M González, R L Oliveira, M C Max, L A Lisboa, T R R Barreiros, M M Santos, F D Sarapião, E L Gastal, M M Seneda
The effect of different concentrations of alpha lipoic acid (ALA) on the development and morphology of preantral follicles, as well as the proliferative activity of granulosa cells, was assessed after short-term culture. Ovaries (n = 5) of five seasonal anestrous mares were harvested in a local abattoir. At the laboratory, nine ovarian fragments (5 × 5 × 1 mm) from each animal were used. One fragment was immediately fixed in Bouin and subjected to histological and immunohistochemistry (proliferating cell nuclear antigen, PCNA) analyses (noncultured group; D0 = day 0)...
September 27, 2017: Theriogenology
Gayathri Pillai, Anurag A Zope, Julius Ming-Lin Tsai, Sheng-Shian Li
We propose an apodization technique based composite thin Film Bulk Acoustic wave Resonator (c-FBAR) design to enable the displacement and strain energy confinement at the central section of the resonator while in operation at the resonance mode. Sinc-shaped AlN on SOI apodized c-FBARs are designed to attain close to 90% energy localization. In this work, single crystal silicon as the mechanical layer and AlN piezoelectric material as the transducer layer of the resonator implemented by InvenSense Inc.'s AlN MEMS-CMOS platform renders an asymmetric feature to the traditional FBAR resonator...
October 5, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Leila Pashazanusi, Moses Oguntoye, Shreyas Oak, Julie N L Albert, Lawrence R Pratt, Noshir S Pesika
We present an exploratory study of the tribological properties between an AFM probe and a Au(111) surface in an aqueous environment while subjected to applied surface potentials. Using a three-electrode setup, the electrical potential and interfacial electric field on a Au(111) working electrode are controlled. Lateral force microscopy is used to measure the friction forces between the AFM probe and the Au surface. As the AFM probe approaches the surface, normal forces are also measured to gain insight into the interfacial forces...
October 13, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
E D Beaton, Marilyne Stuart, Sim Stroes-Gascoyne, Karen J King-Sharp, Ioana Gurban, Amy Festarini, Hui Q Chen
Proposed radioactive waste repositories require long residence times within deep geological settings for which we have little knowledge of local or regional subsurface dynamics that could affect the transport of hazardous species over the period of radioactive decay. Given the role of microbial processes on element speciation and transport, knowledge and understanding of local microbial ecology within geological formations being considered as host formations can aid predictions for long term safety. In this relatively unexplored environment, sampling opportunities are few and opportunistic...
2017: Frontiers in Microbiology
Tongqiao Miao, Dingbang Xiao, Qingsong Li, Zhanqiang Hou, Xuezhong Wu
This paper reports the design and simulation of a 4 mm² double differential torsional MEMS accelerometer based on a double-beam configuration. Based on the structure of conventional torsional accelerometers, normally composed of one pair of proof masses and one torsional beam, this work explores the double differential configuration: a torsional accelerometer with two pairs of unbalanced proof masses rotating in reverse. Also, the torsional beam is designed as a double-beam structure, which is a symmetrical structure formed by two torsional beams separated by a certain distance...
October 2, 2017: Sensors
Naif M Alsubaie, Ahmed A Youssef, Naser El-Sheimy
This paper introduces a new method which facilitate the use of smartphones as a handheld low-cost mobile mapping system (MMS). Smartphones are becoming more sophisticated and smarter and are quickly closing the gap between computers and portable tablet devices. The current generation of smartphones are equipped with low-cost GPS receivers, high-resolution digital cameras, and micro-electro mechanical systems (MEMS)-based navigation sensors (e.g., accelerometers, gyroscopes, magnetic compasses, and barometers)...
September 30, 2017: Sensors
John P Giannini, Andrew G York, Hari Shroff
We describe a method to speed up microelectromechanical system (MEMS) mirror scanning by > 20x, while also improving scan accuracy. We use Landweber deconvolution to determine an input voltage which would produce a desired output, based on the measured MEMS impulse response. Since the MEMS is weakly nonlinear, the observed behavior deviates from expectations, and we iteratively improve our input to minimize this deviation. This allows customizable MEMS angle vs. time with <1% deviation from the desired scan pattern...
2017: PloS One
Jinghua Hu, Mengchun Pan, Jiafei Hu, Sizhong Li, Dixiang Chen, Wugang Tian, Kun Sun, Qingfa Du, Yuan Wang, Long Pan, Weihong Zhou, Qi Zhang, Peisen Li, Junping Peng, Weicheng Qiu, Jikun Zhou
Magnetic modulation methods especially Micro-Electro-Mechanical System (MEMS) modulation can improve the sensitivity of magnetoresistive (MR) sensors dramatically, and pT level detection of Direct Current (DC) magnetic field can be realized. While in a Low Frequency Alternate Current (LFAC) magnetic field measurement situation, frequency measurement is limited by a serious spectrum aliasing problem caused by the remanence in sensors and geomagnetic field, leading to target information loss because frequency indicates the magnetic target characteristics...
September 2017: Review of Scientific Instruments
Randall P Wagner, Steven E Fick
This article reports the first use of the pressure reciprocity technique to calibrate a micro-electromechanical system (MEMS) microphone. This standardized primary calibration method is conventionally used to calibrate laboratory standard microphones. Results for the pressure reciprocity calibration of a MEMS microphone and two laboratory standard microphones are presented for the frequency range 100-10 000 Hz. Because the amplifier in the MEMS microphone package prevents reciprocal operation, this microphone was used only as a receiver of sound...
September 2017: Journal of the Acoustical Society of America
Binghao Liang, Wenjun Chen, Zhongfu He, Rongliang Yang, Zhiqiang Lin, Huiwei Du, Yuanyuan Shang, Anyuan Cao, Zikang Tang, Xuchun Gui
Pressure sensing is a crucial function for flexible and wearable electronics, such as artificial skin and health monitoring. Recent progress in material and device structure of pressure sensors has brought breakthroughs in flexibility, self-healing, and sensitivity. However, the fabrication process of many pressure sensors is too complicated and difficult to integrate with traditional silicon-based Micro-Electro-Mechanical System(MEMS). Here, this study demonstrates a scalable and integratable contact resistance-based pressure sensor based on a carbon nanotube conductive network and a photoresist insulation layer...
September 29, 2017: Small
Mohamed Tarek Moustafa, Claudio Ramirez, Kevin Schneider, Shari R Atilano, Gloria Astrid Limb, Baruch D Kuppermann, Maria Cristina Kenney
PURPOSE: Memantine (MEM) acts on the glutamatergic system by blocking N-methyl-d-aspartate (NMDA) glutamate receptors. The role that MEM plays in protecting retinal cells is unknown. Hydroquinone (HQ) is one of the cytotoxic components in cigarette smoke. In the present study, we tested whether pretreatment with MEM could protect against the cytotoxic effects of HQ on human retinal pigment epithelium cells (ARPE-19) and human retinal Müller cells (MIO-M1) in vitro. METHODS: Cells were plated, pretreated for 6 h with 30 μM of MEM, and then exposed for 24 h to 200, 100, 50, and 25 μM of HQ while MEM was still present...
October 2017: Journal of Ocular Pharmacology and Therapeutics
Satoshi Fujii, Shuntaro Tsubaki, Naomi Inazu, Eiichi Suzuki, Yuji Wada
Scandium is being explored as an alloying element for aluminum alloys, which are gaining importance as high-performance lightweight structural alloys in the transportation industry. A few years ago, Sc was also found to be suitable for use in electrical devices. High-Sc-content ScAlN thin films have attracted significant attention because of their strong piezoelectricity. The piezoelectric response of ScAlN suggests that ScAlN thin films formed on a hard substrate would be suitable surface acoustic wave wideband filters for next-generation wireless communication systems...
September 27, 2017: Materials
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