Sensitivity analysis of the reactor safety study

Originally presented as the first author's thesis, (M.S.)--in the M.I.T. Dept. of Nuclear Engineering, 1979Includes bibliographical references (p. 232-233)Final research project reportFinal report for research project sponsored by Northeast Utilities Service Company, Yankee Atomic Electric Company under the M.I.T. Energy Laboratory Electric Utility Progra

Modifications to the University of Michigan 83‐Inch Cyclotron to Improve Beam Quality

Recent studies of the internal and extracted beams at the higher energies (up to 40‐MeV deuterons and 80‐MeV α‐particles) led us to convert the dee system of the 83‐inch cyclotron from two 150° dees to one 180° dee. The primary purpose was to remove from the deflector channel the rf dee voltage, which because of its phase opposes the dc deflector voltage and in addition introduces an energy spread in the extracted beam. The one‐dee system offers further advantages. The equivalent first harmonic due to a gap‐crossing driving force which is a function of the dee geometry and dee voltage balance in the two‐dee system, is essentially eliminated, and control of the central orbits, in particular the selection of phase width, is facilitated. The measured values of the beam quality and energy spread are in good agreement with calculations. These results, together with the diagnostic instrumentation used in obtaining them, are described.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87291/2/366_1.pd

Lipoxin A4 stable analogs reduce allergic airway responses via mechanisms distinct from CysLT1 receptor antagonism

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154665/1/fsb2fj078653com.pd

A regioselectively 1, 1',3 ,3'-tetrazincated ferrocene complex displaying core and peripheral reactivity

Regioselective 1,1′,3,3′-tetrazincation [C-H to C-Zn(tBu)] of ferrocene has been achieved by reaction of a fourfold excess of di-t-butylzinc (tBu2Zn) with sodium 2,2,6,6-tetramethylpiperidide (NaTMP) in hexane solution manifested in the trimetallic iron-sodium-zinc complex [Na4(TMP)4Zn4(tBu)4{(C5H3)2Fe}], 1. X-ray crystallographic studies supported by DFT modelling reveal the structure to be an open inverse crown in which two [Na(TMP)Zn(tBu)Na(TMP)Zn(tBu)]2+ cationic units surround a {(C5H3)2Fe}4- tetraanion. Detailed C6D6 NMR studies have assigned the plethora of 1H and 13C chemical shifts of this complex. It exists in a major form in which capping and bridging TMP groups interchange, as well as a minor form that appears to be an intermediate in this complicated exchange phenomenon. Investigation of 1 has uncovered two distinct reactivities. Two of its peripheral t-butyl carbanions formally deprotonate toluene at the lateral methyl group to generate benzyl ligands that replace these carbanions in [Na4(TMP)4Zn4(tBu)2(CH2Ph)2{(C5H3)2Fe}], 2, which retains its tetrazincated ferrocenyl core. Benzyl-Na π-arene interactions are a notable feature of 2. In contrast, reaction with pyridine affords the crystalline product {[Na·4py][Zn(py∗)2(tBu)·py]}∞, 3, where py is neutral pyridine (C5H5N) and py∗ is the anion (4-C5H4N), a rare example of pyridine deprotonated/metallated at the 4-position. This ferrocene-free complex appears to be a product of core reactivity in that the core-positioned ferrocenyl anions of 1, in company with TMP anions, have formally deprotonated the heterocycle

Conserving Coastal Wetlands Despite Sea Level Rise

Coastal wetlands provide valuable services such as flood protection and fisheries production to a global population that is increasingly concentrated near the coast and dependent on its resources. Many of the world\u27s coastal wetlands suffered significant losses during this century, and the creation of new wetland areas is not keeping pace with recent losses. Some destruction of wetland areas can be expected as a consequence of the continual reworking of the coastal zone by dynamic geologic processes. Yet human activities also play a role, both directly by encroaching on coastal wetlands and indirectly by influencing the hydrologic and geologic processes in the coastal zone

Rapid Evolution of Enormous, Multichromosomal Genomes in Flowering Plant Mitochondria with Exceptionally High Mutation Rates

A pair of species within the genus Silene have evolved the largest known mitochondrial genomes, coinciding with extreme changes in mutation rate, recombination activity, and genome structure

Utilizing CryoSat-2 sea ice thickness to initialize a coupled ice-ocean modeling system

Two CryoSat-2 sea ice thickness products derived with independent algorithms are used to initialize a coupled ice-ocean modeling system in which a series of reanalysis studies are performed for the period of March 15, 2014–September 30, 2015. Comparisons against moored upward looking sonar, drifting ice mass balance buoy, and NASA Operation IceBridge ice thickness data show that the modeling system exhibits greatly reduced bias using the satellite-derived ice thickness data versus the operational model run without these data. The model initialized with CryoSat-2 ice thickness exhibits skill in simulating ice thickness from the initial period to up to 6 months. We find that the largest improvements in ice thickness occur over multi-year ice. Based on the data periods examined here, we find that for the 18-month study period, when compared with upward looking sonar measurements, the CryoSat-2 reanalyses show significant improvement in bias (0.47–0.75) and RMSE (0.89–1.04) versus the control run without these data (1.44 and 1.60, respectively). An ice drift comparison reveals little change in ice velocity statistics for the Pan Arctic region; however some improvement is seen during the summer/autumn months in 2014 for the Bering/Beaufort/Chukchi and Greenland/Norwegian Seas. These promising results suggest that such a technique should be used to reinitialize operational sea ice modeling systems