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voltage sensor

Guofeng Du, Juan Zhang, Jicheng Zhang, Gangbing Song
The filling of thin-walled steel tubes with quartz sand can help to prevent the premature buckling of the steel tube at a low cost. During an impact, the internal stress of the quartz sand-filled steel tube column is subjected to not only axial force but also lateral confining force, resulting in complicated internal stress. A suitable sensor for monitoring the internal stress of such a structure under an impact is important for structural health monitoring. In this paper, piezoceramic Smart Aggregates (SAs) are embedded into a quartz Sand-Filled Steel Tube Column (SFSTC) to monitor the internal structural stress during impacts...
August 22, 2017: Sensors
Fabio Scholl, Paulo Morais, Rayla Gabriel, Michael J Schöning, Jose Roberto Siqueira, Luciano Caseli
In this paper, carbon nanotubes (CNTs) were incorporated in penicillinase-phospholipid Langmuir and Langmuir-Blodgett (LB) films to enhance the enzyme catalytic properties. Adsorption of the penicillinase and CNTs at dimyristoylphosphatidic acid (DMPA) monolayers at the air-water interface was investigated by surface pressure-area isotherms, vibrational spectroscopy and Brewster angle microscopy. The floating monolayers were transferred to solid supports through the LB technique, forming mixed DMPA-CNTs-PEN films, which were investigated by quartz crystal microbalance, vibrational spectroscopy, and atomic force microscopy...
August 17, 2017: ACS Applied Materials & Interfaces
Darius Saadat-Moghaddam, Jong-Hoon Kim
The accurate measure of DNA concentration is necessary for many DNA-based biological applications. However, the current methods are limited in terms of sensitivity, reproducibility, human error, and contamination. Here, we present a microneedle functionalized with polyethyleneimine (PEI) and single-walled carbon nanotubes (SWCNTs) for the highly sensitive quantification of DNA. The microneedle was fabricated using ultraviolet (UV) lithography and anisotropic etching, and then functionalized with PEI and SWCNTs through a dip coating process...
August 16, 2017: Sensors
Sungmoo Lee, Tristan Geiller, Arong Jung, Ryuichi Nakajima, Yoon-Kyu Song, Bradley J Baker
An improved genetically encoded voltage indicator (GEVI) was achieved by altering the charge composition of the region linking the voltage-sensing domain of the GEVI to a pH-sensitive fluorescent protein. Negatively charged linker segments reduced the voltage-dependent optical signal while positively charged linkers increased the signal size. Arginine scanning mutagenesis of the linker region improved the signal size of the GEVI, Bongwoori, yielding fluorescent signals as high as 20% ΔF/F during the firing of action potentials...
August 15, 2017: Scientific Reports
Rene Barro-Soria, Rosamary Ramentol, Sara I Liin, Marta E Perez, Robert S Kass, H Peter Larsson
KCNE β-subunits assemble with and modulate the properties of voltage-gated K(+) channels. In the heart, KCNE1 associates with the α-subunit KCNQ1 to generate the slowly activating, voltage-dependent potassium current (IKs) in the heart that controls the repolarization phase of cardiac action potentials. By contrast, in epithelial cells from the colon, stomach, and kidney, KCNE3 coassembles with KCNQ1 to form K(+) channels that are voltage-independent K(+) channels in the physiological voltage range and important for controlling water and salt secretion and absorption...
August 14, 2017: Proceedings of the National Academy of Sciences of the United States of America
Giancarlo N Bruni, R Andrew Weekley, Benjamin J T Dodd, Joel M Kralj
Electrically excitable cells harness voltage-coupled calcium influx to transmit intracellular signals, typically studied in neurons and cardiomyocytes. Despite intense study in higher organisms, investigations of voltage and calcium signaling in bacteria have lagged due to their small size and a lack of sensitive tools. Only recently were bacteria shown to modulate their membrane potential on the timescale of seconds, and little is known about the downstream effects from this modulation. In this paper, we report on the effects of electrophysiology in individual bacteria...
August 14, 2017: Proceedings of the National Academy of Sciences of the United States of America
Kai Yan, Yaohua Yang, Yuhan Zhu, Jingdong Zhang
A photocathode-based photocatalytic fuel cell (PFC) was fabricated and proposed as a self-powered sensor for p-nitrophenol (p-NP) detection. The PFC was comprised of a photocathode and an anode in separated chambers, which could generate suitable power output under photoirradiation to drive the sensing process. In this device, p-type PbS quantum dots-modified glass carbon electrode (GCE) served as the photocathode for the reduction of p-NP under photoirradiation while graphene-modified GCE was employed as the anode for the oxidation of ascorbic acid...
August 14, 2017: Analytical Chemistry
Yudan Zhu, Yang Ruan, Yumeng Zhang, Yaojia Chen, Xiaohua Lu, Linghong Lu
The separation behaviors of Mg2+ and Li+ were investigated using molecular dynamics. Two functionalized graphene nanopore models (i.e., co_5 and coo_5) inspired by the characteristic structural features of Mg2+ channels were used. Both nanopores exhibited a higher preference to Mg2+ than to Li+, and the selectivity ratios were higher for coo_5 than for co_5 under all the studied transmembrane voltages. An evaluation of the effect of coordination on the ionic hydration microstructures for both nanopores showed that the positioning of the modified groups could better fit a hydrated Mg2+ than a hydrated Li+, as if Mg2+ was not dehydrated according to hydrogen bond analysis of the ionic hydration shells...
August 13, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Georges Dubourg, Apostolos Segkos, Jaroslav Katona, Marko Radović, Slavica Savić, Georgios Niarchos, Christos Tsamis, Vesna Crnojević-Bengin
This paper describes the fabrication and the characterization of an original example of a miniaturized resistive-type humidity sensor, printed on flexible substrate in a large-scale manner. The fabrication process involves laser ablation for the design of interdigitated electrodes on PET (Poly-Ethylene Terephthalate) substrate and a screen-printing process for the deposition of the sensitive material, which is based on TiO₂ nanoparticles. The laser ablation process was carefully optimized to obtain micro-scale and well-resolved electrodes on PET substrate...
August 11, 2017: Sensors
Peter G Kroth, Christian Wilhelm, Tilman Kottke
Light is important for algae, as it warrants metabolic independence via photosynthesis. In addition to the absorption of light by the photosystems, algae possess a variety of specific photoreceptors that allow the quantification of the light fluxes as well as the assessment of light qualities. About a decade ago, aureochromes have been described in the xanthophyte alga Vaucheria frigida. These proteins represent a new type of blue light photoreceptor as they possess both a light-oxygen-voltage (LOV) domain for light reception as well as a basic region leucine zipper (bZIP) domain for DNA binding, indicating that they represent light-driven transcription factors...
July 11, 2017: Journal of Plant Physiology
Zhao Wang, Lun Tan, Xumin Pan, Gao Liu, Yahua He, Wenchao Jin, Meng Li, Yongming Hu, Haoshuang Gu
The rapid development of micro-scaled piezoelectric energy harvesters has provided a simple and highly efficient way for building self-powered sensor systems through harvesting the mechanical energy from the ambient environment. In this work, a self-powered microfluidic sensor that can harvest the mechanical energy of the fluid and simultaneously monitor their characteristics was fabricated by integrating the flexible piezoelectric poly(vinylidene fluoride) (PVDF) nanofibers with the well-designed microfluidic chips...
August 7, 2017: ACS Applied Materials & Interfaces
Diego Antolín, Nicolás Medrano, Belén Calvo, Pedro A Martínez
This paper presents a low-cost high-efficiency solar energy harvesting system to power outdoor wireless sensor nodes. It is based on a Voltage Open Circuit (VOC) algorithm that estimates the open-circuit voltage by means of a multilayer perceptron neural network model trained using local experimental characterization data, which are acquired through a novel low cost characterization system incorporated into the deployed node. Both units-characterization and modelling-are controlled by the same low-cost microcontroller, providing a complete solution which can be understood as a virtual pilot cell, with identical characteristics to those of the specific small solar cell installed on the sensor node, that besides allows an easy adaptation to changes in the actual environmental conditions, panel aging, etc...
August 4, 2017: Sensors
Qu Zhou, ChangXiang Hong, Yao Yao, Ahmed Mohamed Ibrahim, Lingna Xu, Rajesh Kumar, Sumaia Mohamed Talballa, S H Kim, Ahmad Umar
Highly sensitive acetone chemical sensor was fabricated using ZnO nanoballs modified silver electrode. A low temperature, facile, template-free hydrothermal technique was adopted to synthesize the ZnO nanoballs with an average diameter of 80 ± 10 nm. The XRD and UV-Vis. studies confirmed the excellent crystallinity and optical properties of the synthesized ZnO nanoballs. The electrochemical sensing performance of the ZnO nanoballs modified AgE towards the detection of acetone was executed by simple current-voltage (I-V) characteristics...
July 14, 2017: Materials
Ahmed A Ibrahim, Preeti Tiwari, M S Al-Assiri, A E Al-Salami, Ahmad Umar, Rajesh Kumar, S H Kim, Z A Ansari, S Baskoutas
Herein, we report a facile synthesis, characterization, and electrochemical sensing application of ZnO nanopeanuts synthesized by a simple aqueous solution process and characterized by various techniques in order to confirm the compositional, morphological, structural, crystalline phase, and optical properties of the synthesized material. The detailed characterizations revealed that the synthesized material possesses a peanut-shaped morphology, dense growth, and a wurtzite hexagonal phase along with good crystal and optical properties...
July 13, 2017: Materials
Chunyu Lu, Jicheng Wang, Shubin Yan, Zheng-Da Hu, Gaige Zheng, Liu Yang
We present plasmonic devices, consisting of periodic arrays of graphene nanoribbons (GNRs) and a graphene sheet waveguide, to achieve controllable plasmon-induced transparency (PIT) by numerical simulation. We analyze the bright and dark elements of the GNRs and graphene-sheet waveguide structure. Results show that applying the gate voltage can electrically tune the PIT spectrum. Adjusting the coupling distance and widths of GNRs directly results in a shift of transmission dips. In addition, increased angle of incidence causes the transmission to split into multiple PIT peaks...
June 26, 2017: Materials
Kyung Su Kim, Cheol Hyoun Ahn, Won Jun Kang, Sung Woon Cho, Sung Hyeon Jung, Dae Ho Yoon, Hyung Koun Cho
We have examined the effects of oxygen content and thickness in sputtered InSnO (ITO) electrodes, especially for the application of imperceptible amorphous-InGaZnO (a-IGZO) thin-film transistors (TFTs) in humidity sensors. The imperceptible a-IGZO TFT with 50-nm ITO electrodes deposited at Ar:O₂ = 29:0.3 exhibited good electrical performances with Vth of -0.23 V, SS of 0.34 V/dec, µFE of 7.86 cm²/V∙s, on/off ratio of 8.8 × 10⁷, and has no degradation for bending stress up to a 3.5-mm curvature. The imperceptible oxide TFT sensors showed the highest sensitivity for the low and wide gate bias of -1~2 V under a wide range of relative humidity (40-90%) at drain voltage 1 V, resulting in low power consumption by the sensors...
May 13, 2017: Materials
Yinghua Qiu, Rachel A Lucas, Zuzanna S Siwy
Rectifying pores, which transport ions mainly in one direction blocking the ionic flow in the other, were shown to be important in the preparation of chemical sensors, components of ionic circuits, and mimics of biological channels. Ionic rectification has been shown with various engineered systems, but pores with similar opening diameters often rectify to a various uncontrolled extent. In this Letter we present a system of single meso-pores, whose current-voltage curves and rectification can be tuned with great precision via viscosity and conductivity gradients of solutions placed on both sides of the membrane...
August 4, 2017: Journal of Physical Chemistry Letters
M Oszwaldowski, S El-Ahmar
In this paper, we report on the double Hall sensor structure (DHSS) in which the voltage offset can be effectively reduced. The DHSS is composed of two standard Hall sensors that are activated with two currents from electrically independent current sources. The operation principle of the DHSS is explained in detail, and the concluded properties of the DHSS are confirmed in the experimental part of the paper. The measurements are performed on DHSSs based on InSb thin films. The offset is reduced by about three orders of magnitude...
July 2017: Review of Scientific Instruments
Eddy Krueger, Lana Popović-Maneski, Percy Nohama
A motor neural prosthesis based on surface functional electrical stimulation (sFES) can restore functional movement (e.g., standing, walking) in patients with a spinal cord injury (SCI). sFES generates muscle contractions in antigravity muscles and allows balance-assisted standing. This induced standing has several benefits, such as improved cardiovascular function, decreased incidence of urinary infections, reduced joint contractures, and muscle atrophy. The duration of sFES assisted standing is limited due to the quick onset of muscle fatigue...
August 1, 2017: Artificial Organs
Manel Gasulla, Josep Jordana, Francesc-Josep Robert, Jordi Berenguer
Rectennas, which mainly consist of an antenna, matching network, and rectifier, are used to harvest radiofrequency energy in order to power tiny sensor nodes, e.g., the nodes of the Internet of Things. This paper demonstrates for the first time, the existence of an optimum voltage gain for high-pass L-matching networks used in rectennas by deriving an analytical expression. The optimum gain is that which leads to maximum power efficiency of the rectenna. Here, apart from the L-matching network, a Schottky single-diode rectifier was used for the rectenna, which was optimized at 868 MHz for a power range from -30 dBm to -10 dBm...
July 25, 2017: Sensors
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