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SI Units: 2019 Redefinition01:13

SI Units: 2019 Redefinition

Measurement is an indispensable part of analytical chemistry. The result of measurement helps quantify a substance's physical property and compare it with the physical property of another substance. Each measurement comprises two components - a number indicating the magnitude and a unit of measurement as a standard for comparison. Further, the same quantity can be measured using different units of measurement, which leads to differences in magnitude.
A standard set of units has been defined...
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The Innovation Arena: A Method for Comparing Innovative Problem-Solving Across Groups14:14

The Innovation Arena: A Method for Comparing Innovative Problem-Solving Across Groups

The Innovation Arena is a novel comparative method for studying technical innovation rate per time unit in animals. It is composed of 20 different problem-solving tasks, which are presented simultaneously. Innovations can be carried out freely and the setup is robust with regard to predispositions on an individual, population or species...
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Predicting Products: SN1 vs. SN202:27

Predicting Products: SN1 vs. SN2

Nucleophilic substitution reactions of alkyl halides can proceed via an SN1 or an SN2 mechanism. While in SN2 reactions, the nucleophile attacks the substrate simultaneously as the leaving group departs, in SN1 reactions, the substrate first dissociates to give the carbocation intermediate. Various factors such as the structure of the substrate, the strength of the nucleophile, and the nature of the solvent promote one mechanism over the other.
With increased substitution on the alkyl halide,...
15.9K
In Vivo 2-Photon Calcium Imaging in Layer 2/3 of Mice08:10

In Vivo 2-Photon Calcium Imaging in Layer 2/3 of Mice

To understand network dynamics of microcircuits in the neocortex, it is essential to simultaneously record the activity of a large number of neurons . In-vivo two-photon calcium imaging is the only method that allows one to record the activity of a dense neuronal population with single-cell resolution...
29.4K
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH301:11

ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3

All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
7.3K
Fabrication of Bi2Te3 and Sb2Te3 Thermoelectric Thin Films using Radio Frequency Magnetron Sputtering Technique04:22

Fabrication of Bi2Te3 and Sb2Te3 Thermoelectric Thin Films using Radio Frequency Magnetron Sputtering Technique

The manuscript describes a protocol for radio frequency magnetron sputtering of Bi2Te3 and Sb2Te3 thermoelectric thin films on glass substrates, which represents a reliable deposition method that provides a wide range of applications with the potential for further...
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