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Electrokinetic Power Generation from Liquid Water Microjets

Description: Although electrokinetic effects are not new, only recently have they been investigated for possible use in energy conversion devices. We have recently reported the electrokinetic generation of molecular hydrogen from rapidly flowing liquid water microjets [Duffin et al. JPCC 2007, 111, 12031]. Here, we describe the use of liquid water microjets for direct conversion of electrokinetic energy to electrical power. Previous studies of electrokinetic power production have reported low efficiencies ({approx}3%), limited by back conduction of ions at the surface and in the bulk liquid. Liquid microjets eliminate energy dissipation due to back conduction and, measuring only at the jet target, yield conversion efficiencies exceeding 10%.
Date: February 15, 2008
Creator: Duffin, Andrew M. & Saykally, Richard J.
Partner: UNT Libraries Government Documents Department

Optical properties of the Ce and La ditelluride charge density wave compounds

Description: The La and Ce di-tellurides LaTe{sub 2} and CeTe{sub 2} are deep in the charge-density-wave (CDW) ground state even at 300 K. We have collected their electrodynamic response over a broad spectral range from the far infrared up to the ultraviolet. We establish the energy scale of the single particle excitation across the CDW gap. Moreover, we find that the CDW collective state gaps a very large portion of the Fermi surface. Similarly to the related rare earth tri-tellurides, we envisage that interactions and Umklapp processes play a role in the onset of the CDW broken symmetry ground state.
Date: February 15, 2010
Creator: Lavagnini, M.; Sacchetti, A.; Degiorgi, L.; Shin, K. Y. & Fisher, I. R.
Partner: UNT Libraries Government Documents Department

Relativistic calculations of excitation and ionization of highly charged ions by electron impact

Description: Our rapid relativistic atomic structure program and relativistic distorted-wave programs for excitation and ionization of highly charged ions were further improved. The generalized Briet interaction and other QED corrections were added to the atomic structure program, and the speed of the distorted-wave excitation program was increased by over an order of magnitude over what it was when our initial large-scale relativistic calculations of excitation of Ne-like ions were made. The improved programs were then used to calculate collision strengths for 330 transitions in F-like ions with 22 [le] Z [le] 92 and 248 transitions in Ni-like ions with 60 [le] Z [le] 92. We expanded the relativistic collision program to include an option to use atomic structure data by the well-known multi-configuration Dirac-Fock (MCDF) program of Grant and A coworkers. This was used in calculating collision strengths for the 45 [Delta]n = 0 transitions with n=2 in Be-like ions with 8 [le] Z [le] 92. This relativistic collision strength program was also extended to include an option to include the generalized Breis interaction in the scattering matrix elements and the importance of this for He-like, He-like and Li-like ions with Z = 26, 54 and 92 was studied. The factorization method was applied to ionization. Regardless of the complexity of the ion the ionization cross sections could be written as a sum of the products of a readily calculated coefficient that depends only on ion properties and a hydrogen-like cross section. Work was also done on excitation and ionization by directive and, in some cases spin-polarized electrons, which is of interest for some EBIT experiments and the study of solar flares. We also used our extensive collision strength results to test the
Date: April 15, 1992
Creator: Sampson, D.H.
Partner: UNT Libraries Government Documents Department

Quantized conic sections; quantum gravity

Description: Starting from free relativistic particles whose position and velocity can only be measured to a precision < [Delta]r[Delta]v > [equivalent to] [plus minus] k/2 meter[sup 2]sec[sup [minus]1] , we use the relativistic conservation laws to define the relative motion of the coordinate r = r[sub 1] [minus] r[sub 2] of two particles of mass m[sub 1], m[sub 2] and relative velocity v = [beta]c = [sub (k[sub 1] + k[sub 2]])/ [sup (k[sub 1] [minus] k[sub 2]]) in terms of conic section equation v[sup 2] = [Gamma] [2/r [plus minus] 1/a] where +'' corresponds to hyperbolic and [minus]'' to elliptical trajectories. Equation is quantized by expressing Kepler's Second Law as conservation of angular niomentum per unit mass in units of k. Principal quantum number is n [equivalent to] j + [1/2] with square'' [sub T[sup 2]]/[sup A[sup 2]] = (n [minus]1)nk[sup 2] [equivalent to] [ell][sub [circle dot]]([ell][sub [circle dot]] + 1)k[sup 2]. Here [ell][sub [circle dot]] = n [minus] 1 is the angular momentumquantum number for circular orbits. In a sense, we obtain spin'' from this quantization. Since [Gamma]/a cannot reach c[sup 2] without predicting either circular or asymptotic velocities equal to the limiting velocity for particulate motion, we can also quantize velocities in terms of the principle quantum number by defining [beta][sub n]/[sup 2] = [sub c[sup 2]]/[sup v[sub n[sup 2]] = [sub n[sup 2]]/1([sub c[sup 2]]a/[Gamma]) = ([sub nN[Gamma]]/1)[sup 2]. For the Z[sub 1]e,Z[sub 2]e of the same sign and [alpha] [triple bond] e[sup 2]/m[sub e][kappa]c, we find that [Gamma]/c[sup 2]a = Z[sub 1]Z[sub 2][alpha]. The characteristic Coulomb parameter [eta](n) [triple bond] Z[sub 1]Z[sub 2][alpha]/[beta][sub n] = Z[sub 1]Z[sub 2]nN[sub [Gamma]] then specifies the penetration factor C[sup 2]([eta]) = 2[pi][eta]/(e[sup 2[pi][eta]] [minus] 1]). For unlike charges, with [eta] still taken as positive, C[sup 2]([minus][eta]) = 2[pi][eta]/(1 [minus] e[sup ...
Date: March 15, 1993
Creator: Noyes, H.P.
Partner: UNT Libraries Government Documents Department