233 research outputs found
Israel -- 1977-82 -- Poliomyelitis, International Cooperation -- letter, 1978-07-19
No full textLetter from Tulchinsky, T. H. to Sabin, Albert B. dated 1978-07-19.Sabin Collection Fair Use Policy</a
Consultative Group on Oral Poliomyelitis Vaccine (Sabin Strains) -- 1977-79 -- OPV WHO -- letter, 1978-07-19
No full textLetter from Tulchinsky, T. H. to Sabin, Albert B. dated 1978-07-19.Sabin Collection Fair Use Policy</a
Nuclear Medicine - A Name for Now and the Future
No full textOur article addresses the prevailing trend of new terminology introduced alongside the progress being made in nuclear medicine. Our article provides a historic, current, and future perspective
Is iron unique in promoting electrical conductivity in MOFs?
No full textIdentifying the metal ions that optimize charge transport and charge density in metal–organic frameworks is critical for systematic improvements in the electrical conductivity in these materials. In this work, we measure the electrical conductivity and activation energy for twenty different MOFs pertaining to four distinct structural families: M2(DOBDC)(DMF)2 (M = Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+); H4DOBDC = 2,5-dihydroxybenzene-1,4-dicarboxylic acid; DMF = N,N-dimethylformamide), M2(DSBDC)(DMF)2 (M = Mn2+, Fe2+; H4DSBDC = 2,5-disulfhydrylbenzene-1,4-dicarboxylic acid), M2Cl2(BTDD)(DMF)2 (M = Mn2+, Fe2+, Co2+, Ni2+; H2BTDD = bis(1H-1,2,3-triazolo[4,5-b],[4′,5′-i]dibenzo[1,4]dioxin), and M(1,2,3-triazolate)2 (M = Mg2+, Mn2+, Fe2+, Co2+, Cu2+, Zn2+, Cd2+). This comprehensive study allows us to single-out iron as the metal ion that leads to the best electrical properties. The iron-based MOFs exhibit at least five orders of magnitude higher electrical conductivity and significantly smaller charge activation energies across all different MOF families studied here and stand out materials made from all other metal ions considered here. We attribute the unique electrical properties of iron-based MOFs to the high-energy valence electrons of Fe2+ and the Fe3+/2+ mixed valency. These results reveal that incorporating Fe2+ in the charge transport pathways of MOFs and introducing mixed valency are valuable strategies for improving electrical conductivity in this important class of porous materials
Accounting at Culver Military Academy
No full textvii, 34 p.The author describes an internship with the accounting department at Culver Military Academy as the student billing intern. The author performed student billing duties, the camper and student registration process, and importing data via the computer systems. In the second part, the author researched the techniques of fundamental analysis and used the techniques to evaluate two publicly traded golf club manufacturers
Reversible Capture and Release of Cl₂ and Br₂ with a Redox-Active Metal–Organic Framework
No full textExtreme toxicity, corrosiveness, and volatility pose serious challenges for the safe storage and transportation of elemental chlorine and bromine, which play critical roles in the chemical industry. Solid materials capable of forming stable nonvolatile compounds upon reaction with elemental halogens may partially mitigate these challenges by allowing safe halogen release on demand. Here we demonstrate that elemental halogens quantitatively oxidize coordinatively unsaturated Co(II) ions in a robust azolate metal-organic framework (MOF) to produce stable and safe-to-handle Co(III) materials featuring terminal Co(III)-halogen bonds. Thermal treatment of the oxidized MOF causes homolytic cleavage of the Co(III)-halogen bonds, reduction to Co(II), and concomitant release of elemental halogens. The reversible chemical storage and thermal release of elemental halogens occur with no significant losses of structural integrity, as the parent cobaltous MOF retains its crystallinity and porosity even after three oxidation/reduction cycles. These results highlight a material operating via redox mechanism that may find utility in the storage and capture of other noxious and corrosive gases.National Science Foundation (U.S.) (Award DMR-1452612
[Review of the book Taking root: The origins of the Canadian Jewish community by Gerald Tulchinsky]
No full text- …
