Silver embedded nanostars for SERS with internal reference (SENSIR)

2015 ◽  
Vol 3 (28) ◽  
pp. 7319-7324 ◽  
Author(s):  
Andrew M. Fales ◽  
Tuan Vo-Dinh
Keyword(s):  
Reference Signal ◽  
Internal Reference ◽  
Silver Shell

Reference dye labeled nanostars are embedded in a partial silver shell, retaining the sharp gold tips for non-aggregated SERS of external analytes while providing an internal reference signal.

scholarly journals An Electrophysiological Correlate of Visual Motion Awareness in Man

1998 ◽  
Vol 10 (4) ◽  
pp. 464-471 ◽  
Author(s):  
Thomas Haarmeier ◽  
Peter Thier
Keyword(s):  
Eye Movement ◽  
Smooth Pursuit ◽  
Visual Processing ◽  
Retinal Image ◽  
Visual Motion ◽  
Reference Signal ◽  
Subjective Perception ◽  
Internal Reference ◽  
Signal Encoding ◽  
Physical Attributes

It is usually held that perceptual spatial stability, despite smooth pursuit eye movements, is accomplished by comparing a signal reflecting retinal image slip with an internal reference signal, encoding the eye movement. The important consequence of this concept is that our subjective percept of visual motion reflects the outcome of this comparison rather than retinal image slip. In an attempt to localize the cortical networks underlying this comparison and therefore our subjective percept of visual motion, we exploited an imperfection inherent in it, which results in a movement illusion. If smooth pursuit is carried out across a stationary background, we perceive a tiny degree of illusionary background motion (Filehne illusion, or FI), rather than experiencing the ecologically optimal percept of stationarity. We have recently shown that this illusion can be modified substantially and predictably under laboratory conditions by visual motion unrelated to the eye movement. By making use of this finding, we were able to compare cortical potentials evoked by pursuit-induced retinal image slip under two conditions, which differed perceptually, while being identical physically. This approach allowed us to discern a pair of potentials, a parieto-occipital negativity (N300) followed by a frontal positivity (P300), whose amplitudes were solely determined by the subjective perception of visual motion irrespective of the physical attributes of the situation. This finding strongly suggests that subjective awareness of visual motion depends on neuronal activity in a parietooccipito-frontal network, which excludes the early stages of visual processing.

scholarly journals Heteroleptic Pt(II)-dithiolene-based Colorimetric Chemosensors: Selectivity Control for Hg(II) Ion Sensing

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1385
Author(s):  
Hyokyung Jeon ◽  
Hwahui Ryu ◽  
Inho Nam ◽  
Dong-Youn Noh
Keyword(s):  
Stokes Shift ◽  
Reference Signal ◽  
Internal Reference ◽  
Simple Method ◽  
Precise Control ◽  
Ion Sensing ◽  
The Central Nervous System ◽  
Dmit Ligand ◽  
Selectivity Control ◽  
End Group

Hg2+ ions can accumulate in the natural environment and in organisms, where they cause damage to the central nervous system. Therefore, the detection of Hg2+ ions is essential for monitoring environmental contamination and human health. Herein, we demonstrate a simple method for tuning chemosensor signal ratios that significantly increased chemosensor selectivity for Hg2+ detection. Selectivity tuning was accomplished for chemosensors of the type (diphosphine)Pt(dmit), bearing the two different terminal groups 1,2-bis(diphenylphosphino)ethane (dppe) and 1,2-bis[bis(pentafluorophenyl)phosphino]ethane) (dfppe) due to the modulation of specific intermolecular interactions between the dmit ligand and Hg2+ ion. The structure exhibited a large pseudo-Stokes shift, which was advantageous for the internal reference signal and for eliminating potential artifacts. Straightforward chain-end manipulation enabled the tuning of chemosensor properties without additional chemical alterations. Based on these findings, we propose a new platform for improving the selectivity and sensitivity of colorimetric cation sensors. The results of this study will facilitate the designing of organic materials whose certain properties can be enhanced through precise control of the materials’ chemical hybridization by simple functional end-group manipulation.

Molecular Complexes, V [1, 2] 1H NMR Investigation of the Caffeine Benzene Complex Followed by AUS Correction of Experimental Data Structural Requirements for Substances to Serve as Internal Reference in Investigations of Weak Complexes

1981 ◽  
Vol 36 (12) ◽  
pp. 1618-1627 ◽  
Author(s):  
Helmut Stamm ◽  
Jürgen Stafe
Keyword(s):  
Reference Group ◽  
Reference Signal ◽  
Molecular Complexes ◽  
Complex Model ◽  
Range Shifts ◽  
Nonlinear Behaviour ◽  
Internal Reference ◽  
External Reference ◽  
Weak Complexes ◽  
Scatchard Plots

Abstract The 4 proton signals of caffeine, dissolved in carbon tetrachloride, were investigated as functions of benzene concentrations in a very large concentration range. Shifts of the 4 signals were measured relative to both internal and external reference. Scatchard plots of the internally referenced data were curved downwards, the degree of curving increasing from 7-methyl/8-H to 3-methyl to 1-methyl. The 1-methyl plot even showed a maximum in the observed relative shifts ⊿oi which turned to negative values for high benzene concentrations. Scatchard plots of the externally referenced data were curved upwards.Applying AUS corrections [1, 8] to both sets of data furnished linear Scatchard plots for ah signals. The plots for the 4 protons were parallel to one another in case of the externally referenced data and not parallel for the internally referenced data. Equilibrium quotients K calculated from the externally referenced data for each of the 4 different protons were essentially the same. This gives evidence that the system behaves in accord with the pure 1:1 complex model and does not demand the assumption of simultaneous occurence of higher complexes. The values for K (= .115 l/mol), for the 4 apparent complex shifts (Icpt/K) and for the 4 nuclei specific AUS coefficients a 2 [1, 8] could be confirmed and somewhat improved by a Creswell-Allred processing of the data including AUS correction.The failure of the AUS correction in producing parallel Scatchard plots from internally referenced shifts is caused by the nonlinear floating with the donor concentration of the internal reference signal. The cause of this nonlinear behaviour is analyzed, and arguments are presented that it can be prevented by use of reference substances with only one single reference group per molecule, i.e. the signal of such an internal reference must not have its origin in two or more equivalent nuclei groups within the reference molecule.

Cerebrocerebellar Circuits for the Perceptual Cancellation of Eye-movement-induced Retinal Image Motion

2006 ◽  
Vol 18 (11) ◽  
pp. 1899-1912 ◽  
Author(s):  
Axel Lindner ◽  
Thomas Haarmeier ◽  
Michael Erb ◽  
Wolfgang Grodd ◽  
Peter Thier
Keyword(s):  
Eye Movement ◽  
Retinal Image ◽  
Reference Signal ◽  
Insular Cortex ◽  
Image Motion ◽  
Internal Reference ◽  
Retinal Motion ◽  
Retinal Image Motion ◽  
Perceptual Invariance ◽  
Crus I

Despite smooth pursuit eye movements, we are unaware of resultant retinal image motion. This example of perceptual invariance is achieved by comparing retinal image slip with an internal reference signal predicting the sensory consequences of the eye movement. This prediction can be manipulated experimentally, allowing one to vary the amount of self-induced image motion for which the reference signal compensates and, accordingly, the resulting percept of motion. Here we were able to map regions in CRUS I within the lateral cerebellar hemispheres that exhibited a significant correlation between functional magnetic resonance imaging signal amplitudes and the amount of motion predicted by the reference signal. The fact that these cerebellar regions were found to be functionally coupled with the left parieto-insular cortex and the supplementary eye fields points to these cortical areas as the sites of interaction between predicted and experienced sensory events, ultimately giving rise to the perception of a stable world despite self-induced retinal motion.

Evaluation of a molybdenum sulfide reference electrode in hot alkaline solutions

TAPPI Journal ◽  
2010 ◽  
Vol 9 (7) ◽  
pp. 35-41
Author(s):  
OUTI A. HYÖKYVIRTA ◽  
TOM E. GUSTAFSSON
Keyword(s):  
Molybdenum Disulfide ◽  
Surface Film ◽  
Reference Electrode ◽  
Exposure Period ◽  
Molybdenum Sulfide ◽  
Alkaline Solutions ◽  
Internal Reference ◽  
Cell Potential ◽  
Pulp Digester ◽  
Alkaline Sulfide

This investigation evaluated the applicability of a molybdenum sulfide reference electrode (MSRE) as an internal reference electrode for use in alkaline sulfide solutions over a range of pulp digester liquors at 170°C. The electrode remained stable during the exposure period of two weeks. The experimentally determined half cell potential of the MSRE is E = -0.91 VSHE. The surface of the MSRE was examined by scanning electron microscope (SEM) and electron spectroscopy for chemical analysis (ESCA) to verify the chemical composition of the thin surface film. Based on ESCA studies, the surface film contained molybdenum disulfide and sodium disulfide. During storage of the specimens, sulfide was partly oxidized to sodium sulfite in air. Next to the metallic molybdenum, a mixed molybdenum disulfide and molybdenum hydroxide layer was detected.

Reference Signal Based Tensor Product Expansion for EOG-Related Artifact Separation in EEG

2017 ◽  
Vol E100.A (11) ◽  
pp. 2230-2237
Author(s):  
Akitoshi ITAI ◽  
Arao FUNASE ◽  
Andrzej CICHOCKI ◽  
Hiroshi YASUKAWA
Keyword(s):  
Tensor Product ◽  
Reference Signal

Active control of compressor noise in the machinery room of refrigerators

2019 ◽  
Vol 67 (5) ◽  
pp. 350-362
Author(s):  
J. M. Ku ◽  
W. B. Jeong ◽  
C. Hong
Keyword(s):  
Control System ◽  
Active Control ◽  
Weighting Function ◽  
Reference Signal ◽  
Active Noise Control ◽  
Dominant Frequency ◽  
Time Signal ◽  
Frequency Noise ◽  
Sound Power ◽  
Fxlms Algorithm

The low-frequency noise generated by the vibration of the compressor in the machinery room of refrigerators is considered as annoying sound. Active noise control is used to reduce this noise without any change in the design of the compressor in the machinery room. In configuring the control system, various signals are measured and analyzed to select the reference signal that best represents the compressor noise. As the space inside the machinery room is small, the size of a speaker is limited, and the magnitude of the controller transfer function is designed to be small at low frequencies, the controller uses FIR filter structure converged by the FxLMS algorithm using the pre-measured time signal. To manage the convergence speed for each frequency, the frequency-weighting function is applied to FxLMS algorithm. A series of measurements are performed to design the controller and to evaluate the control performance. After the control, the sound power transmitted by the refrigerator is reduced by 9 dB at the first dominant frequency (408 Hz in this case) and 3 dB at the second dominant frequency (459 Hz here), and the overall sound power decreases by 2.6 dB. Through this study, an active control system for the noise generated by refrigerator compressors is established.

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