Organocatalytic hydrogen bond donor/Lewis base (HBD/LB) synthesis and chiroptical properties of thiabridged [5]helicenes

Thiabridged [5]helicenes are obtained from thioaryl-N-phthalimido benzo[a]phenothiazines using a hydrogen bond donor/Lewis base organocatalytic approach. Resolution of [5]helicenes using either (1S)-(-)-camphanic acid as a chiral auxiliary or CSP-HPLC is reported. Thiabridged [5]helicenes show an exceptional configurational stability with racemization energy barriers higher than 40 kcal mol-1. Electronic circular dichroism and TD-DFT calculations permit the assignment of the absolute configur...

Who Are the Freshmen at Highest Risk of Dropping Out of University? Psychological and Educational Implications

Diritti e responsabilità nelle catene di appalti labour-intensive.

Il passaggio dalla fabbrica fordista ai modelli di organizzazione d'impresa più flessibili propri del postfordismo ha portato alla frammentazione della dimensione del potere all'interno dell’impresa. Questo ha comportato una dissociazione tra il soggetto detentore del potere direttivo e il soggetto organizzatore dei fattori di produzione. Operando sul piano della responsabilità, la scomparsa di questa identità ha compromesso i tradizionali strumenti protettivi dei lavoratori subordinati, basa...

Advanced Image Preprocessing and Integrated Modeling for UAV Plant Image Classification

The automatic identification of plant species using unmanned aerial vehicles (UAVs) is a valuable tool for ecological research. However, challenges such as reduced spatial resolution due to high-altitude operations, image degradation from camera optics and sensor limitations, and information loss caused by terrain shadows hinder the accurate classification of plant species from UAV imagery. This study addresses these issues by proposing a novel image preprocessing pipeline and evaluating its ...