Physical Sciences and Mathematics Commons^™

Concentration, Amount And Counting By Weighing, Julian Tyson

Science and Engineering Saturday Seminars

Concentration, Amount and Counting by Weighing

UMass Amherst STEM Ed Institute Saturday Workshop 2/3/2018

Julian Tyson, Professor Emeritus, Department of Chemistry. Tyson@chem.umass.edu

Session 1. Introductions.

Ice-breaker: The elementarity contest.

Setting the scene: “How much arsenic do we eat?” Why do we want to know? The Consumer Reports articles (Nov 2012 and Nov 2014)

Dealing with really big and really small numbers.

Session 2. Amount, concentration

Solids, liquids and gases. The “parts per” concept.

Session 3. Counting by weighing

The count equation. Rice grains (the bottle content problem), atoms and molecules.. Chemical formulas and balanced chemical expressions. The numbers in the …

Persistent Radical Anion Polymers Based On Naphthalenediimide And A Vinylene Spacer, Sashi Debnath, Connor J. Boyle, Dongming Zhou, Bryan M. Wong, Kevin R. Kittilstved, Dhandapani Venkataraman

Chemistry Department Faculty Publication Series

Persistent n-doped conjugated polymers were achieved by doping the electron accepting PDNDIV and PFNDIVpolymers with ionic (TBACN) or neutral (TDAE) dopants. The great electron affinities, as indicated by the low LUMO levels of PDNDIV (−4.09 eV) and PFNDIV (−4.27 eV), facilitated the chemical reduction from either TBACN or TDAE. The low-lying LUMOs of the neutral polymers PDNDIV and PFNDIV were achieved by incorporation of vinylene spacers between the electron poor NDI units to increase the conjugation length without the use of an electron donor, and this was lowered further by an electron-withdrawing fluorinated N-substituent on the NDI moiety. The …

3' End Additions By T7 Rna Polymerase Are Rna Self-Templated, Distributive And Diverse In Character––Rna-Seq Analyses, Yasaman Gholamalipour, Aruni K. Mudiyanselage, Craig T. Martin

Chemistry Department Faculty Publication Series

Synthetic RNA is widely used in basic science, nanotechnology and therapeutics research. The vast majority of this RNA is synthesized in vitro by T7 RNA polymerase or one of its close family members. However, the desired RNA is generally contaminated with products longer and shorter than the DNA-encoded product. To better understand these undesired byproducts and the processes that generate them, we analyze in vitro transcription reactions using RNA-Seq as a tool. The results unambiguously confirm that product RNA rebinds to the polymerase and self-primes (in cis) generation of a hairpin duplex, a process that favorably competes with promoter driven …