51,441 research outputs found
Letter from Hill Ferguson to Louis D. Boylan, University, Alabama, August 17, 1951
No full textFour letters are enclosed with this letter to Ferguson. The first letter is from Louis D. Boylan, Public Accountant, Louis D. Boylan and Company, University, Alabama, to President John M. Gallalee, University, Alabama, August 13, 1951. The second letter is also from Louis D. Boylan to Buford Boone, Publisher, The Tuscaloosa News, Tuscaloosa, Alabama, July 25, 1951. The third letter is from William N. Perry, Fraternity Auditor, Louis D. Boylan and Company, University, Alabama, to Dean Noble B. Hendrix, Dean of Students, University, Alabama, August 7, 1951. The fourth letter is also from William N. Perry to Louis D. Boylan, Louis D. Boylan and Company, University, Alabama, August 7, 1951
Stepwise Reduction of Dinitrogen Occurring on a Divanadium Model Compound: A Synthetic, Structural, Magnetic, Electrochemical, and Theoretical Investigation on the [V=N=N=V]n+ [n = 4-6] Based Complexes
No full textThis report details an extensive investigation on vanadium-dinitrogen complexes containing the [V(mu-N-2)V](n+) skeleton with a variable oxidation state of the metal and reduction degree of dinitrogen, n varying from 6 --> 5 --> 4. This skeleton can be associated to alkali cations in ion-separated or ion-pair tight forms. The reaction of [(Mes)(3)V(thf)], 1 [Mes = 2,4,6-Me3C6H2], with Lewis acids [AlPh3, B(C6F5)(3)] removed the THF molecule lending under nitrogen to the formation of the diamagnetic complex [(Mes)(3)V(mu-N-2)V(Mes)(3)], 4. The reaction of 1 with N-2 also occurs under reducing conditions using Na or K metals. As supported by the electrochemical study, the preliminary stage is in both cases the formation of the vanadium(II) desolvated form [V(Mes)(3)](-), 5. The reaction of 5 with N-2 in the case of potassium and in the presence of 1 leads to the compound {[Mes)(3)V(mu-N-2)V(Mes)(3)](-)[K(digly)(3)](+)}, 11, which, depending on the reaction conditions, undergoes a further reduction to [{K(digly)(3)(mu-Mes)(2)(Mes)V}(2)(mu-N-2)], 12 [digly = diethylene glycol dimethyl ether]. Similarly, the reduction of 1 with sodium gave, depending on the workup mode, {[(Mes)(3)V(mu-N-2)V(Mes)(3)](2-)[Na(digly)(2)](2)(+)}, 13, or {[(Mes)(3)V(mu-N-2)(mu-Na)V(Mes)(3)](-)[Na(digly)(2)](+)}, 14. both containing the dianion [(Mes)(3)V(mu-N-2)V(Mes)(3)](2-), 8. Complex 1 releases upon protonation exclusively Nz. while complexes 11-14 release N-2, N2H4, and NH3 in amounts depending on the degree of reduction of the dinitrogen and the structure of the complex. The electrochemical reduction of 1 shed light on the intermediate formation of 5 and its conversion to 8, which was oxidized to the monoanion [(Mes)(3)V(mu-N-2)V(Mes)(3)](-), 7 (which is the precursor of 8 in the chemical reduction). The magnetic studies coupled with the theoretical interpretation are in agreement with the presence of a d(2)-d(2) couple in 4, a d(1)-d(1) in 12-14, and a d(1)-d(0) in 11. This, along with the structural studies on 11-14, suggest a cumulenic structure [V=N=N=V](+n) [n = 5, 4] for 11-14
Letter from J. Ferguson to D. N. Cooley, 1865
No full textEncloses power of attorney authorizing him to receive the amount due P. Hussey for services rendered at Fresno Reservation. Power of Attorney not enclosed as indicated by letter
Letter from John Ferguson to D. N. Cooley, 1865
No full textEncloses power of attorney authorizing him to adjust the claim of James R. Jones for supplies furnished Fresno Reservation. Power of Attorney not enclosed as indicated by letter
Letter from J. Ferguson to D. N. Cooley, 1865
No full textEnclosed power of attorney from Geo. Grierson authorizing him to receive certain balances due him. Also the amounts due Wm. B. Cummings and M. B. Lewis
Letter from John Ferguson to D. N. Cooley, 1865
No full textEncloses power of attorney from Lewis Leach authorizing him to adjust certain claims for supplies to Fresno Reservation. Power of Attorney not enclosed as indicated by letter
Letter from J. Ferguson to D. N. Cooley, 1865
No full textEncloses power of attorney from Alex Kennedy authorizing him to adjust the balance due him for Indian service in California. Power of Attorney not enclosed as indicated by letter
Letter from John Ferguson to D. N. Cooley, 1865
No full textEncloses power of attorney for Wm. M. Lewis to his claim for a balance due him for Indian service in California. Power of Attorney not enclosed as indicated by letter
The effect of cubic damping on a base excited isolator: an experimental study for harmonic excitation
No full textAn experimental study has been conducted to validate theoretical solutions for the response of a base excited single degree-of-freedom isolation system possessing pure cubic damping. The cubic damping characteristic was implemented using an electromagnetic shaker with a simple non-linear velocity feedback control. The rig and practical implementation of the active damping are described. The base excitation was harmonic at a set of discrete frequencies with constant displacement amplitude. Consistent with theoretical predictions, the isolation performance at high excitation frequencies is shown to be worse than either the undamped or linear viscously damped isolation system with the displacement transmissibility tending to unity. This is contrary to the case of force excitation reported in the literature where cubic damping offers improved performance. The physical causes of the distinct behaviours and the consequences for isolator design are discusse
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