scholarly journals Decoding the Kinetic Limitations of Plasmon Catalysis: The Case of 4-Nitrothiophenol Dimerization

2020 ◽  
Author(s):  
Wouter Koopman ◽  
Radwan M. Sarhan ◽  
Felix Stete ◽  
Clemens N. Z. Schmitt ◽  
Matias Bargheer
Keyword(s):  
Thermal Effects ◽  
Dominant Role ◽  
Relative Importance ◽  
New Approach ◽  
Multistep Reaction ◽  
Kinetics Of ◽  
Complex Organic ◽  
Insight Into ◽  
Unique Ability

Plasmon-mediated chemistry presents an intriguing new approach to photocatalysis. However, the reaction enhancement<br>mechanism is not well understood. In particular, the relative importance of plasmon-generated hot charges and<br>photoheating are strongly debated. In this article, we evaluate the influence of microscopic photoheating on the kinetics of<br>a model plasmon-catalyzed reaction: the light-induced 4-nitrothiophenol (4NTP) to 4,4’-dimercaptoazobenzene (DMAB)<br>dimerization. Direct measurement of the reaction temperature by nanoparticle Raman-thermometry demonstrated that<br>the thermal effect plays a dominant role in the kinetic limitations of this multistep reaction. On the same time, no reaction<br>is possible by dark heating to the same temperature. This shows that plasmon nanoparticles have the unique ability to<br>enhance several steps of complex tandem reactions simultaneously. These results provide insight into the role of hot<br>electron and thermal effects in plasmonic catalysis of complex organic reactions, which highly important for the ongoing<br>development of plasmon based photosynthesis. <br>

scholarly journals Decoding the Kinetic Limitations of Plasmon Catalysis: The Case of 4-Nitrothiophenol Dimerization

2020 ◽  
Author(s):  
Wouter Koopman ◽  
Radwan M. Sarhan ◽  
Felix Stete ◽  
Clemens N. Z. Schmitt ◽  
Matias Bargheer
Keyword(s):  
Thermal Effects ◽  
Dominant Role ◽  
Relative Importance ◽  
New Approach ◽  
Multistep Reaction ◽  
Kinetics Of ◽  
Complex Organic ◽  
Insight Into ◽  
Unique Ability

Plasmon-mediated chemistry presents an intriguing new approach to photocatalysis. However, the reaction enhancement<br>mechanism is not well understood. In particular, the relative importance of plasmon-generated hot charges and<br>photoheating are strongly debated. In this article, we evaluate the influence of microscopic photoheating on the kinetics of<br>a model plasmon-catalyzed reaction: the light-induced 4-nitrothiophenol (4NTP) to 4,4’-dimercaptoazobenzene (DMAB)<br>dimerization. Direct measurement of the reaction temperature by nanoparticle Raman-thermometry demonstrated that<br>the thermal effect plays a dominant role in the kinetic limitations of this multistep reaction. On the same time, no reaction<br>is possible by dark heating to the same temperature. This shows that plasmon nanoparticles have the unique ability to<br>enhance several steps of complex tandem reactions simultaneously. These results provide insight into the role of hot<br>electron and thermal effects in plasmonic catalysis of complex organic reactions, which highly important for the ongoing<br>development of plasmon based photosynthesis. <br>

scholarly journals Simulation of Folding Kinetics for Aligned RNAs

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 347
Author(s):  
Jiabin Huang ◽  
Björn Voß
Keyword(s):  
Evolutionary Conservation ◽  
Folding Kinetics ◽  
New Approach ◽  
Computational Approaches ◽  
Reasonable Time ◽  
Valuable Method ◽  
Kinetics Of ◽  
Insight Into ◽  
Folding Space ◽  
Standing Problem

Studying the folding kinetics of an RNA can provide insight into its function and is thus a valuable method for RNA analyses. Computational approaches to the simulation of folding kinetics suffer from the exponentially large folding space that needs to be evaluated. Here, we present a new approach that combines structure abstraction with evolutionary conservation to restrict the analysis to common parts of folding spaces of related RNAs. The resulting algorithm can recapitulate the folding kinetics known for single RNAs and is able to analyse even long RNAs in reasonable time. Our program RNAliHiKinetics is the first algorithm for the simulation of consensus folding kinetics and addresses a long-standing problem in a new and unique way.

scholarly journals Dynamics of Tpm1.8 domains on actin filaments with single molecule resolution

2020 ◽  
Author(s):  
Ilina Bareja ◽  
Hugo Wioland ◽  
Miro Janco ◽  
Philip R. Nicovich ◽  
Antoine Jégou ◽  
...  
Keyword(s):  
Actin Filament ◽  
Single Molecule ◽  
Actin Filaments ◽  
High Probability ◽  
Actin Binding ◽  
Single Molecule Level ◽  
Filament Dynamics ◽  
Kinetics Of ◽  
Insight Into

ABSTRACTTropomyosins regulate dynamics and functions of the actin cytoskeleton by forming long chains along the two strands of actin filaments that act as gatekeepers for the binding of other actin-binding proteins. The fundamental molecular interactions underlying the binding of tropomyosin to actin are still poorly understood. Using microfluidics and fluorescence microscopy, we observed the binding of fluorescently labelled tropomyosin isoform Tpm1.8 to unlabelled actin filaments in real time. This approach in conjunction with mathematical modeling enabled us to quantify the nucleation, assembly and disassembly kinetics of Tpm1.8 on single filaments and at the single molecule level. Our analysis suggests that Tpm1.8 decorates the two strands of the actin filament independently. Nucleation of a growing tropomyosin domain proceeds with high probability as soon as the first Tpm1.8 molecule is stabilised by the addition of a second molecule, ultimately leading to full decoration of the actin filament. In addition, Tpm1.8 domains are asymmetrical, with enhanced dynamics at the edge oriented towards the barbed end of the actin filament. The complete description of Tpm1.8 kinetics on actin filaments presented here provides molecular insight into actin-tropomyosin filament formation and the role of tropomyosins in regulating actin filament dynamics.

Kinetics of Plasmon-Driven Hydrosilylation of Silicon Surfaces: Photogenerated Charges Drive Silicon- Carbon Bond Formation

2021 ◽  
Author(s):  
Chengcheng Rao ◽  
Brian Olsen ◽  
Erik Luber ◽  
Jillian Buriak
Keyword(s):  
Green Light ◽  
Kinetic Studies ◽  
Silicon Surfaces ◽  
Moderate Intensity ◽  
Carbon Bond ◽  
Silicon Carbon ◽  
Set Up ◽  
Kinetics Of ◽  
Insight Into

Optically transparent PDMS stamps coated with a layer of gold nanoparticles were employed as plasmonic stamps to drive surface chemistry on silicon surfaces. Illumination of a sandwich of plasmonic stamps, an alkene ink, and hydride-terminated silicon with green light of moderate intensity drives hydrosilylation on the surface. The key to the mechanism of the hydrosilylation is the presence of holes at the Si-H-terminated interface, which is followed by attack by a proximal alkene and formation of the silicon-carbon bond. In this work, detailed kinetic studies of the hydrosilylation on silicon with different doping levels, n++, p++, n, p, and intrinsic were carried out to provide further insight into the role of the metal-insulator-semiconductor (MIS) junction that is set up during the stamping.

Dynamic Crushing of All-Metallic Corrugated Panels Filled With Close-Celled Aluminum Foams

2015 ◽  
Vol 82 (1) ◽  
Author(s):  
B. Yu ◽  
B. Han ◽  
C. Y. Ni ◽  
Q. C. Zhang ◽  
C. Q. Chen ◽  
...  
Keyword(s):  
Aluminum Foam ◽  
Sandwich Panel ◽  
Dominant Role ◽  
Sandwich Panels ◽  
Rate Sensitivity ◽  
Aluminum Foams ◽  
Foam Filling ◽  
Plastic Hardening ◽  
Insight Into

Under quasi-static uniaxial compression, inserting aluminum foams into the interstices of a metallic sandwich panel with corrugated core increased significantly both its peak crushing strength and energy absorption per unit mass. This beneficial effect diminished however if the foam relative density was relatively low or the compression velocity became sufficiently high. To provide insight into the varying role of aluminum foam filler with increasing compression velocity, the crushing response and collapse modes of all metallic corrugate-cored sandwich panels filled with close-celled aluminum foams were studied using the method of finite elements (FEs). The constraint that sandwich panels with and without foam filling had the same total weight was enforced. The effects of plastic hardening and strain rate sensitivity of the strut material as well as foam/strut interfacial debonding were quantified. Three collapse modes (quasi-static, transition, and shock modes) were identified, corresponding to different ranges of compression velocity. Strengthening due to foam insertion and inertial stabilization both acted to provide support for the struts against buckling. At relatively low compression velocities, the struts were mainly strengthened by the surrounding foam; at high compression velocities, inertia stabilization played a more dominant role than foam filling.

A Quantitative Method to Explore the Assimilation Effects

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 217-217
Author(s):  
E Kroon ◽  
M J H Puts ◽  
C M M de Weert
Keyword(s):  
Test Stimulus ◽  
Stimulus Object ◽  
Object Segmentation ◽  
Matching Task ◽  
New Approach ◽  
Assimilation Effect ◽  
Black And White ◽  
Central Processing ◽  
Insight Into

The role of central processes in the assimilation effect can easily be shown qualitatively (de Weert and Spillmann, 1995 Vision Research35 1413 – 1419), but it is difficult to measure quantitatively because of the subtlety of the effect. In most experimental designs, the match stimulus differs greatly in appearance from the test stimulus, eg in size or configuration, and because these differences are far more striking than the assimilation effect, matching is difficult. Central processing, eg object segmentation, influences colour spreading. It is this property that we explored with a new approach: a matching task in which the match stimulus has the same properties (eg size and configuration) as the test stimulus. Object segmentation is forced by stereopsis-induced depth. The test stimulus consists of two depth planes, one with black dots and the other with white dots, on a homogeneous gray background. The match stimulus has the same configuration of black and white dots, but now squeezed into a single depth plane. The basic idea behind this stimulus is that assimilation mainly acts on the back plane of a scene (as can be shown experimentally). So, while keeping the appearance of the stimulus the same, subjects can focus on the assimilation effect itself. This new approach allows us to explore more aspects of the assimilation effect and gain insight into the processes involved.

scholarly journals The role of reward-based crowdfunding in farm financing: What characterises successful campaign?

2021 ◽  
Vol 68 (3) ◽  
pp. 773-788
Author(s):  
Isidora Ljumović ◽  
Aida Hanić ◽  
Vlado Kovačević
Keyword(s):  
Logistic Regression ◽  
Logistic Regression Model ◽  
Project Success ◽  
Positive Impact ◽  
Investment Decisions ◽  
Significant Negative Correlation ◽  
The Self ◽  
Relative Importance ◽  
Insight Into

The purpose of this paper is to provide insight into the role of reward-based crowdfunding in farm financing, with a focus on its likelihood of success. The study uses a sample of 1,566 projects from the Kickstarter platform between 2014 and 2020. We added the level of urbanisation and relative importance of agriculture in the country's economy to the basic elements to assess the importance of the crowdfunding. We run a logistic regression model to investigate factors that motivate investment decisions. We discovered a statistically significant negative correlation between the self-set campaign goal and project success, as well as a small positive impact of number of backers and a positive impact of the importance of agriculture in the country's economy on crowdfunding success. In an era of rapid innovation and the rise of social networks, this paper contributes to the current literature on the agri-food industry's reword-based crowdfunding approach.

Insight into the role of piperazine in the thermodynamics and nucleation kinetics of the triethylenediamine–methyl tertiary butyl ether system

CrystEngComm ◽  
2019 ◽  
Vol 21 (6) ◽  
pp. 948-956 ◽  
Author(s):  
Yufeng Quan ◽  
Yang Yang ◽  
Shijie Xu ◽  
Peipei Zhu ◽  
Shiyuan Liu ◽  
...  
Keyword(s):  
Crystal Size ◽  
Methyl Tertiary Butyl Ether ◽  
Nucleation Kinetics ◽  
Butyl Ether ◽  
Tertiary Butyl ◽  
System P ◽  
Kinetics Of ◽  
Insight Into ◽  
Ether System

Considering the role of piperazine in the TEDA–MTBE system, we investigate how to control the crystal size distribution.

Kinetics of Plasmon-Driven Hydrosilylation of Silicon Surfaces: Photogenerated Charges Drive Silicon- Carbon Bond Formation

2021 ◽  
Author(s):  
Chengcheng Rao ◽  
Brian Olsen ◽  
Erik Luber ◽  
Jillian Buriak
Keyword(s):  
Green Light ◽  
Kinetic Studies ◽  
Silicon Surfaces ◽  
Moderate Intensity ◽  
Carbon Bond ◽  
Silicon Carbon ◽  
Set Up ◽  
Kinetics Of ◽  
Insight Into

Optically transparent PDMS stamps coated with a layer of gold nanoparticles were employed as plasmonic stamps to drive surface chemistry on silicon surfaces. Illumination of a sandwich of plasmonic stamps, an alkene ink, and hydride-terminated silicon with green light of moderate intensity drives hydrosilylation on the surface. The key to the mechanism of the hydrosilylation is the presence of holes at the Si-H-terminated interface, which is followed by attack by a proximal alkene and formation of the silicon-carbon bond. In this work, detailed kinetic studies of the hydrosilylation on silicon with different doping levels, n++, p++, n, p, and intrinsic were carried out to provide further insight into the role of the metal-insulator-semiconductor (MIS) junction that is set up during the stamping.

A New Approach to Study the Degradation of the Organic Pollutants by A-Doped MxOy/B Photocatalysts

2021 ◽  
Author(s):  
Mojtaba Arabameri ◽  
Hadis Bashiri
Keyword(s):  
Experimental Data ◽  
Organic Pollutants ◽  
Vital Role ◽  
Effective Concentration ◽  
Computational Method ◽  
Operational Parameters ◽  
New Approach ◽  
New Variables ◽  
Kinetics Of

Abstract This work presents a new approach and a comprehensive mechanism to study the kinetics of the photodegradation of the organic pollutants. The vital role of various operational factors on the degradation of the organic pollutants is explained using this method. The proposed approach is based on the simple strategies and a powerful computational method. Two new variables “the effective concentration of photon” (Ieff) and “the effective concentration of the reactive-centers” (RC) are defined to better understanding the effect of operational parameters on the organic pollutants photodegradation. The optimum conditions of the photocatalytic degradation can be determined with the help of this method. This approach was used to study the kinetics of photodegradation of the organic pollutants on the A - doped MxOy/B photocatalysts. The provided mechanism has been examined with the some experimental data. The high correlations between the experimental data and the fitting results under different conditions prove this mechanism could be reliable.

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