A novel piezoelectrically actuated 2-DoF compliant micro/nano-positioning stage with multi-level amplification
This article presents a novel two-degrees-of-freedom (2-DoF) piezo-actuated parallel-kinematic micro/nano-positioning stage with multi-level amplification. Themirror symmetric stage consists of four leverage mechanisms, two Scott-Russell mechanisms, and a Z-shaped flexure hinge (ZFH) mechanism. Taking advantage of the ZFH mechanism, 2-DoFmotions with final-level flexural amplification and decoupledmotion guidance are achieved. Analytical models of the stage are developed and validated throughfinite element analysis to characterize its working performance. Practical testing of a prototype stage is conducted to demonstrate t...
Source: Review of Scientific Instruments - October 31, 2016 Category: Physics Authors: Wu-Le Zhu, Zhiwei Zhu, Yi Shi, Xiangfan Chen, Yu He, Kornel F. Ehmann and Bing-Feng Ju Source Type: research
Resonant photodetector for cavity- and phase-locking of squeezed state generation
Based on the requirement ofsqueezed state generation, we build the phase relationship between two electronic local oscillators for the cavity- and phase-locking branches, and a 2-way 90 ° power splitter is adopted to satisfy the phase relationship simultaneously, which greatly simplifies the experimental setup and adjusting process. A LC parallel resonant circuit, which is composed by the inherent capacitance of aphotodiode and an extrainductor, is adopted in the resonant photodetector to improve the gain factor at the expected frequency. The gain of the resonant photodetector is about 30 dB higher than that of the broadb...
Source: Review of Scientific Instruments - October 31, 2016 Category: Physics Authors: Chaoyong Chen, Zhixiu Li, Xiaoli Jin and Yaohui Zheng Source Type: research
Development of an electrochemically integrated SR-GIXRD flow cell to study FeCO3 formation kinetics
An electrochemically integrated Synchrotron Radiation-Grazing IncidenceX-Ray Diffraction (SR-GIXRD) flow cell for studyingcorrosion product formation oncarbon steel incarbon dioxide (CO2)-containing brines typical of oil and gas production has been developed. The system is capable of generating flow velocities of up to 2 m/s at temperatures in excess of 80 °C during SR-GIXRDmeasurements of the steel surface, enabling flow to be maintained over the course of the experiment whilediffraction patterns are being collected. The design of the flow cell is presented, along withelectrochemical anddiffraction pattern transients ...
Source: Review of Scientific Instruments - October 28, 2016 Category: Physics Authors: D. Burkle, R. De Motte, W. Taleb, A. Kleppe, T. Comyn, S. M. Vargas, A. Neville and R. Barker Source Type: research
Regional regularization method for ECT based on spectral transformation of Laplacian
Image reconstruction in electricalcapacitancetomography is an ill-posedinverse problem, and regularization techniques are usually used to solve the problem for suppressing noise. Ananisotropic regional regularization algorithm for electricalcapacitancetomography is constructed using a novel approach called spectral transformation. Its function is derived and applied to the weighted gradient magnitude of the sensitivity of Laplacian as a regularization term. With the optimum regional regularizer, thea priori knowledge on the local nonlinearity degree of the forward map is incorporated into the proposed onlinereconstruction ...
Source: Review of Scientific Instruments - October 28, 2016 Category: Physics Authors: Z. H. Guo, Z. Kan, D. C. Lv and F. Q. Shao Source Type: research
X-ray reflectometer for single layer and multilayer coating characterization at 8 keV: An interlaboratory study
AnX-rayreflectometer (XRR) system has been developed at the Marshall Space Flight Center (MSFC) for characterizing various soft and hardX-ray opticcoatings. The XRR instrument generatesX-ray radiation using a high-output rotating anode source (RAS), operational over a voltage range of 5 –35 kV and a current range of 10–150 mA. Copper is used as the target material to produce anX-ray spectrum from which the Kα line at 8.048 keV is isolated for thereflectivity measurements. Five precision slits are mounted along theX-ray beam path to limit the extent of the beam at the sample and to adjust the resolution in the measurem...
Source: Review of Scientific Instruments - October 28, 2016 Category: Physics Authors: Danielle N. Gurgew, David M. Broadway, Mikhail Gubarev, Brian D. Ramsey and Don A. Gregory Source Type: research
Development of a polarization-modulation spectroscopy system for the temporally resolved measurement of linear polarization in plasma emission
A system tomeasure linearpolarization in the HeI 21P –31D emission line (667.8 nm) was developed for application to plasmapolarizationspectroscopy. To verify the system performance, the normalized Stokes parameters were evaluated. Ameasurement error of less than 1% with a time resolution of 1ms was achieved for monochromatic light in the state of complete linearpolarization. (Source: Review of Scientific Instruments)
Source: Review of Scientific Instruments - October 28, 2016 Category: Physics Authors: Kenji Yasui, Taiichi Shikama, Takanori Higashi and Masahiro Hasuo Source Type: research
Enhancement of the transversal magnetic optic Kerr effect: Lock-in vs. hysteresis method
The lock-inamplifier is often used to study the enhancement of themagneto-optical Kerr effect(MOKE) in the presence ofplasmonresonances. In the present work we show that it is possible to investigate such effect replacing the lock-inamplifier by a compensator, filter, and differentialamplifier. This allows us to extract the fullhysteresis loop in and out of theresonance without the need of a lock-inamplifier. Our results demonstrate these two setups are equivalent to study the enhancement of the transversalMOKE (T-MOKE) in magnetoplasmonic systems. (Source: Review of Scientific Instruments)
Source: Review of Scientific Instruments - October 28, 2016 Category: Physics Authors: Jorge Nicol ás Hayek, César A. Herreño-Fierro and Edgar J. Patiño Source Type: research
Pulsed neutron time-dependent intensity modulation for quasi-elastic neutron scattering spectroscopy
We propose a basic formula and demonstration for a high-resolution quasi-elasticneutron scattering (QENS) by combining thetime-of-flight(TOF) method with Modulation of Intensity by Zero Effort (MIEZE) typeneutronspin echospectroscopy. The MIEZE technique has the potential to develop a unique approach to study on slow dynamics of condensed matter; however, the energy resolution is limited owing to the hypersensitivity of the MIEZE signal contrast to the echo condition, which is strongly affected by the alignment of the instruments and the sample. The narrow allowance of the optimal alignment is a major obstacle to the wide ...
Source: Review of Scientific Instruments - October 27, 2016 Category: Physics Authors: T. Oda, M. Hino, M. Kitaguchi, P. Geltenbort and Y. Kawabata Source Type: research
Dilatometer setup for low coefficient of thermal expansion materials measurements in the 140 K-250 K temperature range
Space applications demand light weightmaterials with excellent dimensional stability fortelescopes, optical benches, optical resonators, etc. Glass-ceramics andcomposite materials can be tuned to reach very low coefficient ofthermal expansion (CTE) at differenttemperatures. In order to determine such CTEs, very accurate setups are needed. Here we present a dilatometer that is able tomeasure the CTE of a large variety ofmaterials in thetemperature range of 140 K to 250 K. The dilatometer is based on aheterodyneinterferometer with nanometer noise levels tomeasure theexpansion of a sample when applying small amplitude control...
Source: Review of Scientific Instruments - October 26, 2016 Category: Physics Authors: Ruven Spannagel, Ines Hamann, Josep Sanjuan, Thilo Schuldt, Martin Gohlke, Ulrich Johann, Dennis Weise and Claus Braxmaier Source Type: research
A long time low drift integrator with temperature control
The output of an operationalamplifier always contains signals that could not have been predicted, even with knowledge of the input and an accurately determined closed-loop transfer function. These signals lead to integrator zero-drift over time. A new type of integrator system with a long-term low-drift characteristic has therefore been designed. The integrator system is composed of a temperature control module and an integrator module. Thealuminum printed circuit board of the integrator is glued to athermoelectric cooler to maintain the electronic components at a stable temperature. The integration drift is automatically ...
Source: Review of Scientific Instruments - October 26, 2016 Category: Physics Authors: Donglai Zhang, Xiaolan Yan, Enchao Zhang and Shimin Pan Source Type: research
Design of a biologically inspired lower limb exoskeleton for human gait rehabilitation
This paper proposes a novelbionic model of the human leg according to the theory of physiology. Based on this model, we present a biologically inspired 3-degree of freedom (DOF) lower limb exoskeleton for human gait rehabilitation, showing that the lower limb exoskeleton is fully compatible with the human knee joint. The exoskeleton has a hybrid serial-parallelkinematic structure consisting of a 1-DOF hip joint module and a 2-DOF knee joint module in the sagittal plane. A planar 2-DOF parallel mechanism is introduced in the design to fully accommodate themotion of the human knee joint, which features not only rotation but ...
Source: Review of Scientific Instruments - October 25, 2016 Category: Physics Authors: Mingxing Lyu, Weihai Chen, Xilun Ding, Jianhua Wang, Shaoping Bai and Huichao Ren Source Type: research
Channelized broadband signal spectrum analysis based on weighted overlap-add structure
The digital channelization technology has been applied in many electronic areas, and the real-timebroadbandspectrumanalysis has been the research hotspot in the area ofsignal processing. This paper introduces the channelizedbroadband signalspectrumanalysis method. Based on the weighted overlap-add (WOLA) structure, this method divides the inputbroadband signal into several sub-bands or channels, and then downconverts and decimates the sub-band signals to obtain the baseband signals with a low sampling rate. Thespectrumanalysis results of the inputbroadband signal are achieved by conducting further decimation, fastFourier t...
Source: Review of Scientific Instruments - October 25, 2016 Category: Physics Authors: Lianping Guo, Jun Jiang, Feng Tan, Huiqing Pan, Peng Zhang, Hao Zeng and Lihong Bai Source Type: research
Sample environment for in situ synchrotron corrosion studies of materials in extreme environments
A newin situ sample environment has been designed and developed to study the interfacial interactions of nuclearcladding alloys with high temperature steam. The sample environment is particularly optimized for synchrotronX-ray diffraction studies forin situ structural analysis. The sample environment is highlycorrosion resistant and can be readily adapted for steam environments. Thein situ sample environment design complies with G2 ASTM standards for studyingcorrosion inzirconium and its alloys and offers remote temperature and pressure monitoring during thein situ data collection. The use of thein situ sample environment ...
Source: Review of Scientific Instruments - October 25, 2016 Category: Physics Authors: Mohamed S. Elbakhshwan, Simerjeet K. Gill, Arthur T. Motta, Randy Weidner, Thomas Anderson and Lynne E. Ecker Source Type: research
Development of a Marx-coupled trigger generator with high voltages and low time delay
Coupled by the Marx of the “JianGuang-I” facility, a high voltage, low time-delay triggergenerator was developed. Working principles of this triggergenerator and its key issues were described in detail. Structures of thisgenerator were also carefully designed and optimized. Based on the “JianGuang-I” Marxgenerator, a test stand was established. And a series of experiment tests were carried out to the study performance of this triggergenerator. Experiment results show that the output voltage of this triggergenerator can be continuously adjusted from 58 kV to 384 kV. The time delay (from the beginning of the Marx-dis...
Source: Review of Scientific Instruments - October 25, 2016 Category: Physics Authors: Yixiang Hu, Jiangtao Zeng, Fengju Sun, Peitian Cong, Zhaofeng Su, Shi Yang, Xinjun Zhang and Ai ’ci Qiu Source Type: research
On the use of strain sensor technologies for strain modal analysis: Case studies in aeronautical applications
This paper discusses the use ofoptical fiberBragg grating(FBG) and piezo strainsensors for structural dynamicmeasurements. For certain industrial applications, there is an interest to use strainsensors rather than in combination with accelerometers for experimentalmodal analysis. Classical electrical strain gauges can be used hereto, but other types of strainsensors are an interesting alternative with some very specific advantages. This work gives an overview of two types of dynamic strainsensors, applied to two industrial applications (ahelicopter main rotor blade and an F-16aircraft),FBGsensors and dynamic piezo strainse...
Source: Review of Scientific Instruments - October 25, 2016 Category: Physics Authors: F ábio Luis Marques dos Santos and Bart Peeters Source Type: research
