Microsphere Coupled Mach-Zehnder Interferometer for Biochemical Sensor

2013 ◽  
Vol 284-287 ◽  
pp. 2885-2889
Author(s):  
Yun Dong Zhang ◽  
Jing Zhang ◽  
He Tian ◽  
Ping Yuan
Keyword(s):  
Glucose Solution ◽  
Solution Concentration ◽  
Steep Slope ◽  
Frequency Range ◽  
High Quality ◽  
Interference Structure ◽  
Biochemical Sensor ◽  
Highly Sensitive ◽  
Narrow Frequency Range ◽  
Spectral Responses

We present the microsphere coupled Mach–Zehnder interference structure. We theoretically calculate that spectral responses of this structure vary with the glucose solution concentrations. It can produce the sharply asymmetric Fano resonance line shape related to the slope between zero and unity transmission. The variation of the normalized transmission is linearly related to the solution concentration. This structure is the promising highly sensitive biochemical sensor due to high quality factor resonance and steep slope over a very narrow frequency range

Alerting and Message Components in Songs of Rufous-Sided Towhees

Behaviour ◽  
1981 ◽  
Vol 76 (3-4) ◽  
pp. 223-249 ◽  
Author(s):  
Douglas G. Richards
Keyword(s):  
Signal Detection Theory ◽  
Field Experiments ◽  
Species Recognition ◽  
Defense Responses ◽  
Time Of Arrival ◽  
Sufficient Information ◽  
Passerine Birds ◽  
Frequency Range ◽  
Narrow Frequency Range ◽  
Species Specific

AbstractIn numerous species of passerine birds the initial few notes of the song have a narrow frequency range and wide temporal spacing when compared with the rest of the song. This structure is well adapted for high detectability when the song is acoustically degraded during passage through the environment. The song of the rufous-sided towhee (Pipilo eythrophtalmus) consists of relatively tonal introductory syllables followed by a complex rapid trill. The trill is capable of carrying more information than the introduction, but is inherently less detectable at a distance owing to degradation by reverberation, amplitude fluctuation, and frequency-dependent attenuation. Signal detection theory predicts that the detectability of the trill will be increased when it is preceded by the introductory syllables, owing to the removal of uncertainty concerning the time of arrival of the signal. This is alerted detection. I performed field experiments using playback of recorded song to towhees to test the hypothesis that these introductory syllables facilitate detection of conspecific song at a distance. Tape recordings of normal and artificially degraded full songs, introduction, and trills were played to territorial male towhees. Normal songs, degraded songs, and normal trills elicited strong territorial defense responses, indicating recognition as adequate species-specific song, and confirming that sufficient information is contained in the trill for species recognition. Degraded trills alone elicited little response. Both normal and degraded introductions also elicited little response, demonstrating that the increased response to a degraded full song over that to a degraded trill is not due to any species-specific characteristics of the introduction, but rather to its function as an alerting stimulus.

scholarly journals A broadband two axis flux-gate magnetometer

1998 ◽  
Vol 41 (3) ◽  
Author(s):  
P. Palangio
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
High Sensitivity ◽  
Magnetic Sensors ◽  
Frequency Range ◽  
Field Station ◽  
Low Weight ◽  
Highly Sensitive ◽  
Flux Gate ◽  
Magnetic Field Variations

A broadband two axis flux-gate magnetometer was developed to obtain high sensitivity in magnetotelluric measurements. In magnetotelluric sounding, natural low frequency electromagnetic fields are used to estimate the conductivity of the Earth's interior. Because variations in the natural magnetic field have small amplitude(10-100 pT) in the frequency range 1 Hz to 100 Hz, highly sensitive magnetic sensors are required. In magnetotelluric measurements two long and heavy solenoids, which must be installed, in the field station, perpendicular to each other (north-south and east-west) and levelled in the horizontal plane are used. The coil is a critical component in magnetotelluric measurements because very slight motions create noise voltages, particularly troublesome in wooded areas; generally the installation takes place in a shallow trench. Moreover the coil records the derivative of the variations rather than the magnetic field variations, consequently the transfer function (amplitude and phase) of this sensor is not constant throughout the frequency range 0.001-100 Hz. The instrument, developed at L'Aquila Geomagnetic Observatory, has a flat response in both amplitude and phase in the frequency band DC-100 Hz, in addition it has low weight, low power, small volume and it is easier to install in the field than induction magnetometers. The sensivity of this magnetometer is 10 pT rms.

scholarly journals Pre-selection of the candidate fields for deep imaging of the epoch of reionization with SKA1-low

2020 ◽  
Vol 499 (3) ◽  
pp. 3434-3444
Author(s):  
Qian Zheng ◽  
Xiang-Ping Wu ◽  
Quan Guo ◽  
Melanie Johnston-Hollitt ◽  
Huanyuan Shan ◽  
...  
Keyword(s):  
Surface Brightness ◽  
Low Frequency ◽  
Far Field ◽  
Frequency Range ◽  
High Quality ◽  
Average Surface ◽  
Square Kilometre Array ◽  
Broad Frequency Range ◽  
Deep Imaging ◽  
Selection Of

ABSTRACT The Square Kilometre Array (SKA) will be the first low-frequency instrument with the capability to directly image the structures of the epoch of reionization (EoR). Indeed, deep imaging of the EoR over five targeted fields of 20 sq deg each has been selected as the highest priority science objective for SKA1. Aiming at preparing for this highly challenging observation, we perform an extensive pre-selection of the ‘quietest’ and ‘cleanest’ candidate fields in the southern sky to be suited for deep imaging of the EoR using existing catalogues and observations over a broad frequency range. The candidate fields should meet a number of strict criteria to avoid contaminations from foreground structures and sources. The candidate fields should also exhibit both the lowest average surface brightness and smallest variance to ensure uniformity and high-quality deep imaging over the fields. Our selection eventually yields a sample of 7 ‘ideal’ fields of 20 sq deg in the southern sky that could be targeted for deep imaging of the EoR. Finally, these selected fields are convolved with the synthesized beam of SKA1-low stations to ensure that the effect of sidelobes from the far-field bright sources is also weak.

scholarly journals Multi-Frequency Synthesis

1991 ◽  
Vol 131 ◽  
pp. 171-179
Author(s):  
J. E. Conway
Keyword(s):  
Frequency Synthesis ◽  
Frequency Range ◽  
Image Fidelity ◽  
Narrow Frequency Range ◽  
Multiple Frequencies

AbstractA method of improving image fidelity by using observations at multiple frequencies is described. We discuss the power and possible limitations of the technique. Results of narrow frequency range observations with MERLIN and global VLBI are presented. We conclude with a consideration of the possible future impact of this technique.

Design of Discretely Tunable Resonant Actuators Using Additive Inertial Units

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Thomas W. Secord ◽  
Troy R. Louwagie ◽  
Robert J. Kopas
Keyword(s):  
General Framework ◽  
Voice Coil Motor ◽  
Energy Requirements ◽  
Frequency Range ◽  
Optimization Scheme ◽  
General Utility ◽  
Theoretical Design ◽  
Narrow Frequency Range ◽  
Resonant Actuators ◽  
Good Agreement

Abstract Resonance is known to reduce the input energy requirements of various actuator systems. The favorable effects of resonance, however, are limited to a narrow frequency range. To overcome this limitation, we describe a general framework for using discrete units of inertia that can be activated in a binary sense to move a resonant frequency across a desired frequency range. We also enumerate the generalized physical cases in which actuators can energetically benefit from resonance. We develop closed-form optimal results for the idealized case of two binary additive inertial units and extend this to a general optimization scheme for higher numbers of units that introduce parasitic friction and added stiffness. We illustrate the concept of binary tuning with a representative linear translational system powered by a voice coil motor (VCM). The experimental results show good agreement with the intended theoretical design and show the general utility of the binary additive inertia approach.

scholarly journals Student Sensor Lab at Home: Safe Repurposing of Your Gadgets

2020 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
Alexander N. Kalashnikov ◽  
Ali Elyounsi ◽  
Alan Holloway
Keyword(s):  
Learning Experience ◽  
Electronic Devices ◽  
Frequency Range ◽  
High Quality ◽  
Potential Harm ◽  
Electronic Circuitry ◽  
Conventional Teaching ◽  
Audible Frequency ◽  
Periodic Safety ◽  
At Home

The COVID-19 pandemic imposed various restrictions on the accessibility of conventional teaching laboratories. Enabling learning and experimenting at home became necessary to support the practical element of students’ learning. Unfortunately, it is not viable to provide or share a fully featured sensor lab to every student because of the prohibitive costs involved. Therefore, repurposing electronic devices that are common to students can bring about the sought-after practical learning experience without the hefty price tag. In distinction to the conventional lab instruments, however, consumer-grade devices are not designed for use with external sensors and/or electronic circuitry. They are not professionally maintained, do not undergo periodic safety tests, and are not calibrated. Nevertheless, nearly all modern computers, laptops, tablets or smartphones are equipped with high-quality audio inputs and outputs that can generate and record signals in the audible frequency range (20 Hz–20 kHz). Despite cutting off the direct currents completely, this range might be sufficient for working with a variety of sensors. In this presentation we look at the possibilities of making sure that such repurposing by design prevents any potential harm to the learner and to her or his personal equipment. These features seem essential for unsupervised lone experimenting and avoiding damage to expensive devices.

scholarly journals Multiple-Jet Needleless Electrospinning Approach via a Linear Flume Spinneret

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2052 ◽  
Author(s):  
Liang Wei ◽  
Chengkun Liu ◽  
Xue Mao ◽  
Jie Dong ◽  
Wei Fan ◽  
...  
Keyword(s):  
Process Parameters ◽  
Applied Voltage ◽  
Mass Production ◽  
Solution Concentration ◽  
Average Error ◽  
High Quality ◽  
Needleless Electrospinning ◽  
Nanofiber Diameter ◽  
Multiple Jets ◽  
Spinning Process

There is a great limitation to improving the quality and productivity of nanofibers through the conventional single-needle method. Using needleless electrospinning technology to generate multiple jets and enhance the productivity of nanofibers has attracted lots of interest for many years. This study develops a novel linear flume spinneret to fabricate nanofibers. Multiple jets with two rows can be formed simultaneously on the surface of the spinneret. The solution concentration has a significant impact on the average nanofiber diameter compared with applied voltage and collection distance. The effects of different spinning process parameters on the productivity of nanofibers are investigated. High-quality nanofibers with small nanofiber diameter and error can be fabricated successfully. The average nanofiber diameter is 108 ± 26 nm. The average error is 24%. The productivity of nanofibers can reach 4.85 ± 0.36 g/h, which is about 24 times more than that of the single-needle method. This novel linear flume spinneret needleless electrospinning technology exhibits huge potential for mass production of nanofibers in the field of industrialization.

Highly sensitive UV photodetectors fabricated using high-quality single-crystalline CVD diamond films

2004 ◽  
Vol 13 (4-8) ◽  
pp. 858-862 ◽  
Author(s):  
Tokuyuki Teraji ◽  
Satoshi Yoshizaki ◽  
Hideki Wada ◽  
Mitsuhiro Hamada ◽  
Toshimichi Ito
Keyword(s):  
Diamond Films ◽  
Cvd Diamond ◽  
High Quality ◽  
Single Crystalline ◽  
Uv Photodetectors ◽  
Highly Sensitive
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