scholarly journals The Influence of Reaction Time on Non-Covalent Functionalisation of P3HT/MWCNT Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1916
Author(s):  
N.M. Nurazzi ◽  
N. Abdullah ◽  
S.Z.N. Demon ◽  
N.A. Halim ◽  
I.S. Mohamad
Keyword(s):  
Reaction Time ◽  
Photoelectron Spectroscopy ◽  
Reaction Times ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Regioregular Poly ◽  
The Mean ◽  
Novel Applications ◽  
Polymer Wrapping

Non-covalent functionalisation of the carbon nanotube (CNT) sidewall through polymer wrapping is the key strategy for improving well-dispersed CNTs without persistent alteration of their electronic properties. In this work, the effect of reaction time on regioregular poly (3-hexylthiophene-2,5-diyl) (P3HT)-wrapped hydroxylated multi-walled CNT (MWCNT-OH) nanocomposites was investigated. Five different reaction times (24, 48, 72, 96, and 120 h) were conducted at room temperature in order to clearly determine the factors that influenced the quality of wrapped MWCNT-OH. Morphological analysis using Field Emission Scanning Electron Microscopic (FESEM) and High-Resolution Transmission Electron Microscope (HRTEM) analysis showed that P3HT successfully wrapped the MWCNT-OH sidewall, evidenced by the changes in the mean diameter size of the nanocomposites. Results obtained from Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS) as well as Thermogravimetric Analysis (TGA) showed a significant effect of the wrapped polymer on the CNT sidewall as the reaction time increased. Overall, the method used during the preparation of P3HT-wrapped MWCNT-OH and the presented results significantly provided a bottom-up approach to determine the effect of different reaction times on polymer wrapping to further expand this material for novel applications, especially chemical sensors.

Modeling Within-Person Variance in Reaction Time Data of Older Adults

GeroPsych ◽  
2011 ◽  
Vol 24 (4) ◽  
pp. 169-176 ◽  
Author(s):  
Philippe Rast ◽  
Daniel Zimprich
Keyword(s):  
Reaction Time ◽  
Cognitive Aging ◽  
Reaction Times ◽  
Reaction Time Task ◽  
Reaction Time Data ◽  
Scale Model ◽  
Time Data ◽  
Time Task ◽  
The Mean ◽  
Second Wave

In order to model within-person (WP) variance in a reaction time task, we applied a mixed location scale model using 335 participants from the second wave of the Zurich Longitudinal Study on Cognitive Aging. The age of the respondents and the performance in another reaction time task were used to explain individual differences in the WP variance. To account for larger variances due to slower reaction times, we also used the average of the predicted individual reaction time (RT) as a predictor for the WP variability. Here, the WP variability was a function of the mean. At the same time, older participants were more variable and those with better performance in another RT task were more consistent in their responses.

How Recyclability can Reduce Induction Period of Gold Nanocatalysts

2019 ◽  
Vol 57 ◽  
pp. 1-6 ◽  
Author(s):  
Sedigheh Ghadamgahi
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Gold Particle ◽  
Particle Diameter ◽  
Gold Catalysts ◽  
Gold Particles ◽  
Transmission Electron ◽  
The Mean ◽  
Full Conversion ◽  
Catalytic Test

The effect of recyclability on the catalytic activity of supported Au101(PPh3)21Cl5 nanoparticles (1.0 wt% Au101/AC) was investigated for benzyl alcohol oxidation under mild conditions. The influence of recyclability on the catalytic activity of activated Au101/AC nanocatalysts was studied trough a comparison of gold particle diameter and also catalysts conversion between the fresh (as synthesized) and recycled gold catalysts. The monitoring of gold particle diameters by transmission electron microscopy (TEM) showed that the gold particles size gradually increased during the catalytic reaction. The mean diameter of the fresh gold catalysts increased from approximately 3 to 3.2, 5.1 and 5.3 nm after 1, 2 and 3 h reaction time, respectively. Whereas the average gold particle diameter of the recycled samples were slightly enlarged from approximately 5.3 (the sample recycled after 3 h of the first catalytic test) to 5.7, 5.9 and 6.2 nm with durations of 1, 2 and 3 h reaction time, respectively. Therefore, larger gold particles gradually formed for fresh and also recycled gold catalysts during reaction tests. Meanwhile, the catalytic activity of activated 1.0 wt% Au101/AC catalysts jumped to full conversion when the recycled gold catalysts were utilized due to removing ligand stabilizer from gold particles and so bigger particles had formed.

Effect of Visual Complexity in Identification of Tachistoscopic Images

1994 ◽  
Vol 78 (3) ◽  
pp. 971-978 ◽  
Author(s):  
Robert Geheb ◽  
Keith E. Whitfield ◽  
Linda Brannon
Keyword(s):  
Reaction Time ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Visual Complexity ◽  
Reaction Times ◽  
Right Cerebral Hemisphere ◽  
The Mean ◽  
The Times ◽  
The Right ◽  
Mean Reaction Time

The present study of gender differences in hemispheric processing involved identification of tachistoscopically presented images of varying complexity. A computerized tachistoscopic program was administered to 24 men and 34 women. Time to identify contour and detailed pictures presented to the left or right cerebral hemisphere was recorded. Mean reaction time for contour pictures was significantly faster than for detailed pictures, and mean reaction time to the right hemisphere was significantly faster than that to the left hemisphere. The mean reaction time for men to identify pictures exposed to the left hemisphere was significantly slower than that for exposure to the right hemisphere for women. The mean reaction time for both men and women to identify contour pictures exposed to the right hemisphere was significantly faster than the mean time to identify detailed pictures presented to the left hemisphere. The interaction of gender, hemisphere, and complexity was also significant in that mean reaction times for men to identify detailed pictures presented to the left hemisphere were slower than the times for women to identify contour pictures presented to the right hemisphere. The results are discussed in relation to theories about hemispheres, gender, and differences in picture features.

NdFe2O4 Nanoparticles: Synthesis, Characterization, and Magnetic Properties

2020 ◽  
Vol 12 (6) ◽  
pp. 810-814 ◽  
Author(s):  
Xiao-Lei Song ◽  
Yi-Lin Wu ◽  
Si-Ran Zhang ◽  
Zhi Chen ◽  
Yong-Gui Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Solvothermal Method ◽  
Energy Dispersive Spectrometer ◽  
Reaction Times ◽  
Spherical Particles ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetic Parameters ◽  
Transmission Electron

Multi-structured NdFe2O4 magnetic nanoparticles (NPs) were successfully prepared at different reaction times through a convenient solvothermal method. The microstructure and elemental composition of the NPs were characterized using powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) technique. An energy dispersive spectrometer (EDS) was connected to a scanning electron microscope to determine the weight and atomic percent of the prepared products. Subsequently, high-resolution transmission electron microscopy (HR/TEM) and TEM were performed at 3, 7, 11, and 15 h to elucidate the synthetic mechanism of the rare-earth element Nd doped in Fe3O4. The magnetic activities of the NPs were evaluated using a vibrating sample magnetometer (VSM). XRD, EDS, and XPS analyses show that Nd was successfully doped into Fe3O4 without breaking its crystal structure. Procedural single-crystal nanosheets and final spherical particles of NdFe2O4 were verified by TEM. The magnetic parameters of the products were further analyzed using the VSM.

A freeze-fracture electron microscopic study of Frankia in root nodules of Alnus incana grown at three oxygen tensions

1990 ◽  
Vol 36 (2) ◽  
pp. 97-108 ◽  
Author(s):  
R. M. Abeysekera ◽  
William Newcomb ◽  
W. B. Silvester ◽  
John G. Torrey
Keyword(s):  
Root Nodules ◽  
Freeze Fracture ◽  
Alnus Incana ◽  
Electron Microscopic ◽  
Protection Mechanism ◽  
Transmission Electron ◽  
Actinorhizal Nodules ◽  
The Mean ◽  
Cell Envelopes ◽  
Fracture Electron

Nodulated plants of Alnus incana ssp. rugosa and ssp. incana were grown with the roots exposed to 5, 21, and 40 kPa O2. The nodules were studied by freeze-fracture transmission electron microscopy to determine the effect of varying O2 tension on the numbers of lipid laminae in the Frankia envelope. Lipid laminae were present in the cell envelopes of hyphae, stalks, and symbiotic vesicles. The mean number of lipid laminae in hyphal envelopes varied from five to nine. Stalks of symbiotic vesicles contained mean numbers of 35–59 lipid laminae over the range of pO2's studied. Symbiotic vesicle envelopes showed mean numbers of lipid laminae varying from 48 to 94. The numbers of lipid laminae were observed to increase significantly in the distal regions of the symbiotic vesicles in response to raised pO2 while the numbers on the proximal portions remained unchanged. The increase in the numbers of lipid laminae in response to raised pO2 was not sufficient to account for the expected increase in resistance to O2 required at the symbiotic vesicle envelope if lipid laminae formed the exclusive diffusion barrier to O2. These results suggest that lipid laminae surrounding symbiotic vesicles may not constitute the only O2 protection mechanism in Alnus nodules. Key words: Alnus incana, Frankia, nitrogen fixation, actinorhizal nodules, Actinomycetes.

scholarly journals Universal kinetics of imperfect reactions in confinement

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Thomas Guérin ◽  
Maxim Dolgushev ◽  
Olivier Bénichou ◽  
Raphaël Voituriez
Keyword(s):  
Reaction Time ◽  
Transport Process ◽  
Reaction Times ◽  
Complex Environments ◽  
Analytical Treatment ◽  
Volume Limit ◽  
Normal Diffusion ◽  
The Mean ◽  
Kinetics Of ◽  
Mean Reaction Time

AbstractChemical reactions generically require that particles come into contact. In practice, reaction is often imperfect and can necessitate multiple random encounters between reactants. In confined geometries, despite notable recent advances, there is to date no general analytical treatment of such imperfect transport-limited reaction kinetics. Here, we determine the kinetics of imperfect reactions in confining domains for any diffusive or anomalously diffusive Markovian transport process, and for different models of imperfect reactivity. We show that the full distribution of reaction times is obtained in the large confining volume limit from the knowledge of the mean reaction time only, which we determine explicitly. This distribution for imperfect reactions is found to be identical to that of perfect reactions upon an appropriate rescaling of parameters, which highlights the robustness of our results. Strikingly, this holds true even in the regime of low reactivity where the mean reaction time is independent of the transport process, and can lead to large fluctuations of the reaction time - even in simple reaction schemes. We illustrate our results for normal diffusion in domains of generic shape, and for anomalous diffusion in complex environments, where our predictions are confirmed by numerical simulations.

Temporal Characteristics of Interstimulus Interval in Serial Choice Reaction Time,

1973 ◽  
Vol 37 (3) ◽  
pp. 723-726
Author(s):  
Robert P. Fishburne ◽  
Wayne L. Waag
Keyword(s):  
Reaction Time ◽  
Choice Reaction Time ◽  
Interstimulus Interval ◽  
Reaction Times ◽  
Reaction Time Task ◽  
Choice Reaction Time Task ◽  
Interval Duration ◽  
Random Interval ◽  
Temporal Characteristics ◽  
The Mean

The present study investigated the effects of presentation schedule and interstimulus interval duration in a serial choice reaction-time task. 45 Ss were randomly assigned to fixed, patterned, and random schedules having durations of interstimulus intervals of 2, 3, and 4 sec. As the regularity of the presentation schedule decreased, reaction time increased. For fixed-interval presentation, reaction time increased as a function of duration while the quickest reaction times occurred at the mean interstimulus interval for random-interval presentation. Reaction times remained the same under the patterned-interval presentation schedule.

Nonthermal Plasma-Assisted Synthesis of Molybdenum Carbide Thin Film Catalysts

2007 ◽  
Vol 1 (1) ◽  
Author(s):  
G. Campbell ◽  
K. Nelson ◽  
C. L. Heitzman ◽  
K. Brezinsky ◽  
A. Saveliev
Keyword(s):  
Photoelectron Spectroscopy ◽  
Molybdenum Carbide ◽  
Nonthermal Plasma ◽  
Ethylene Concentration ◽  
Transmission Electron ◽  
Thin Film Catalysts ◽  
Catalyst Production ◽  
Novel Method ◽  
Water Gas

Optimization of the nonthermal plasma-assisted method of synthesizing molybdenum carbide thin films on molybdenum particle substrates was initiated using a previously existing experimental setup. The yield of the apparatus used has increased by 20% as the result of redesign. The molybdenum carbide produced through nonthermal plasma has been characterized by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It is tentatively observed by using the TEM that an ethylene concentration of 3% gives the best molybdenum carbide surface layer. The quality of the product is unclear, indicating that further characterization is necessary. This novel method of catalyst production has been tested in very preliminary experiments with a water-gas shift reactor and the CO2 conversion was 0.5%, suggesting, again, that further optimization is necessary.

Dislocation Dynamics In B.C.C. Metals: A Nuclear Magnetic Resonance and Transmission Electron Microscopic Study

1990 ◽  
Vol 209 ◽  
Author(s):  
J. Th. M. De Hosson ◽  
O. Kanert
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Dislocation Dynamics ◽  
Electron Microscopic ◽  
Static Structure ◽  
Transmission Electron ◽  
Jump Distance ◽  
Transmission Electron Microscopic ◽  
The Mean ◽  
Nuclear Magnetic

ABSTRACTPulsed nuclear magnetic resonance proved to be a complementary new technique for the study of moving dislocations in b.c.c. metals. From the motion induced part of the spin-lattice relaxation rate the mean jump distance of mobile dislocationshas been measured in Vanadium as a function of temperature. The NMR experiments are combined with transmission electron microscopic investigations to reveal the static structure of defects in the samples. The NMR experiments show that the mean jump distance is nearly constant below 230 K whereas it decreases substantially above 230 K to 300 K indicating a transition that marks two different mechanisms. NMR observations in combination with TEM support the physical picture that above that transition temperature dislocation segments are stopped between localized obstacles whereas below Tc the latticefriction controls the plastic behaviour.

scholarly journals Influence of Reaction Time in the Emotional Response of a Companion Robot to a Child’s Aggressive Interaction

2020 ◽  
Vol 12 (6) ◽  
pp. 1279-1291 ◽  
Author(s):  
Ahmad Yaser Alhaddad ◽  
John-John Cabibihan ◽  
Andrea Bonarini
Keyword(s):  
Reaction Time ◽  
Emotional Response ◽  
Cognitive Disabilities ◽  
Reaction Times ◽  
Late Response ◽  
Aggressive Interaction ◽  
Aggressive Interactions ◽  
Significant Difference

AbstractThe quality of a companion robot’s reaction is important to make it acceptable to the users and to sustain interactions. Furthermore, the robot’s reaction can be used to train socially acceptable behaviors and to develop certain skills in both normally developing children and children with cognitive disabilities. In this study, we investigate the influence of reaction time in the emotional response of a robot when children display aggressive interactions toward it. Different interactions were considered, namely, pickup, shake, drop and throw. The robot produced responses as audible sounds, which were activated at three different reaction times, namely, 0.5 s, 1.0 s, and 1.5 s. The results for one of the tasks that involved shaking the robotic toys produced a significant difference between the timings tested. This could imply that producing a late response to an action (i.e. greater than 1.0 s) could negatively affect the children’s comprehension of the intended message. Furthermore, the response should be comprehensible to provide a clear message to the user. The results imply that the designers of companion robotic toys need to consider an appropriate timing and clear modality for their robots’ responses.

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