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Delocalizing the radical ion stabilizes the transition state structure. As a result, the energy of activation decreases, enhancing the rate of the overall reaction. According to the captodative effect, the rate of a reaction is the greatest when both the EDG and EWG are able to delocalize the radical ion in the transition state structure. [7]
An electron donating group (EDG) or electron releasing group (ERG, Z in structural formulas) is an atom or functional group that donates some of its electron density into a conjugated π system via resonance (mesomerism) or inductive effects (or induction)—called +M or +I effects, respectively—thus making the π system more nucleophilic.
The oil and gas industry uses many acronyms and abbreviations. This list is meant for indicative purposes only and should not be relied upon for anything but general information. This list is meant for indicative purposes only and should not be relied upon for anything but general information.
[11] [page needed]) For ortho-para directing groups (electron donating group or EDG), σ’ more positive than σ meta and σ para. The difference between σ para and σ’ (σ para – σ’) is greater than that between σ meta and σ’(σ meta − σ’). This is expected as electron resonance effects are felt more strongly at the p-positions.
The EPC contractor coordinates all design, procurement and construction work and ensures that the whole project is completed as required and in time. They may or may not undertake actual site work. EPC companies are often used in large-scale projects, such as power plants, refineries, chemical processing facilities, infrastructure projects, and ...
The construction industry contributes significantly to many countries' gross domestic products . Global expenditure on construction activities was about $4 trillion in 2012. In 2022, expenditure on the construction industry exceeded $11 trillion a year, equivalent to about 13 percent of global GDP. This spending was forecasted to rise to around ...
A typical construction engineering curriculum is a mixture of engineering mechanics, engineering design, construction management and general science and mathematics. This usually leads to a Bachelor of Science degree. The B.S. degree along with some design or construction experience is sufficient for most entry-level positions.
Modern methods of construction (MMC) is a term used mainly in the UK construction industry to refer to "smart construction" processes designed to improve upon traditional design and construction approaches by focusing on (among other things) component and process standardisation, design for manufacture and assembly (), prefabrication, preassembly, off-site manufacture (including modular ...