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This paper presents an analytical solution of reactive transport with equilibrium and kinetic reactions. A benchmark model of A {leftrightarrow} B {leftrightarrow} C {yields} chain reactions is developed for the purpose of verifying numerical computer codes and qualifying mathematical models. A reaction matrix is derived for both the equilibrium and first-order kinetic reactions and further decoupled as a diagonal matrix. Therefore, the partial differential equations (PDEs) coupled by the reaction matrix can be transformed into independent PDEs, for which closed-form solutions exist or can be derived. The analytical solution derived in this paper is compared with numerical results.

Using synchrotron angle-dispersive x-ray diffraction (ADXD) and Raman spectroscopy on samples of Li{sub 2}O pressurized in a diamond anvil cell, we observed a reversible phase change from the cubic antifluorite ({alpha}, Fm-3m) to orthorhombic anticotunnite ({beta}, Pnma) phase at 50({+-}5) GPa at ambient temperature. This transition is accompanied by a relatively large volume collapse of 5.4 ({+-}0.8)% and large hysteresis upon pressure reversal (P{sub down} at {approx} 25 GPa). Contrary to a recent study, our data suggest that the high-pressure {beta}-phase (B{sub o} = 188 {+-} 12 GPa) is substantially stiffer than the low-pressure {alpha}-phase (B{sub o} = 90 {+-} 1 GPa). A relatively strong and pressure-dependent preferred orientation in {beta}-Li{sub 2}O is observed. The present result is in accordance with the systematic behavior of antifluorite-to-anticotunnite phase transitions occurring in the alkali-metal sulfides.

Free weekly newspaper that includes business and classified advertising.

Letter from Betty Brown to Eleanor Brown thanking her for agreeing to remain in her position on the WASP board.

Weekly newspaper from Rusk, Texas that includes local, state and national news along with extensive advertising.

Daily student newspaper from the University of North Texas in Denton, Texas that includes local, state and campus news along with advertising.

Weekly student newspaper from the University of Dallas in Irving, Texas that includes campus news and commentaries along with advertising.

Photograph of a woman wearing red boxing gloves with her left hand up by her chin and right hand by her chest.

Photograph of two women and a boxing instructor at a gym. The instructor is wrapping hand wraps around the palms of the lady wearing a red shirt while the lady in a white shirt observes.

Photograph of two young men in boxing attire fighting each other in a boxing ring. There are several people shown outside the ring watching the young men fight.

Photograph of a girl and a boy jumping rope at a boxing gym. A man is shown behind them leaning toward a boxing ring and another man is seated inside the ring.

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Weekly student newspaper from Texas Wesleyan University in Fort Worth, Texas that includes campus and local news along with advertising.

This report gives an overview of key environmental issues receiving attention in the 109th Congress.

Letter from Ken Whalen to the TDNA Directors on April 12, 2006 with the subject Appointment of New Director. The letter begins with the news that Guy Kerr has resigned his position as a director on the TDNA board, and that a nomination committee, lead by President Jeremy L. Halbreich has recommended Austin American-Statesman executive vice president and general manger, Belinda Gaudet to fill Kerr's two-year term. Attached to the letter is a response form to be filled out by the directors with their ultimate decision.

Free weekly newspaper that includes business and classified advertising.

Free weekly newspaper that includes business and classified advertising.

This report discusses various proposals to amend the Endangered Species Act of 1973 (ESA; P.L. 93-205, 16 U.S.C. §§1531-1543). Major issues include changing the role of science in decision-making, modifying critical habitat (CH) procedures, reducing conflicts with Department of Defense activities, incorporating further protection and incentives for property owners, and increasing protection of listed species, among others.

A new method to estimate remanent dose rates, to be used with the Monte Carlo code FLUKA, was benchmarked against measurements from an experiment that was performed at the CERN-EU high-energy reference field facility. An extensive collection of samples of different materials were placed downstream of and laterally to a copper target, intercepting a positively charged mixed hadron beam with a momentum of 120 GeV/c. Emphasis was put on the reduction of uncertainties such as careful monitoring of the irradiation parameters, the use of different instruments to measure dose rates, detailed elemental analyses of the irradiated materials and detailed simulations of the irradiation experiment. Measured and calculated dose rates are in good agreement.

During the nuclear testing era, the former Soviet Union carried out extensive observations of underground nuclear explosions, recording both their own shots and those of foreign nuclear states. Between 1961 and 1989, the Soviet Complex Seismological Expedition deployed seismometers at time-varying subsets of over 150 sites to record explosions at regional distances from the Semipalatinsk and Lop Nor test sites and from the shot points of peaceful nuclear explosions. This data set included recordings from broadband, multi-channel ChISS seismometers that produced a series of narrow band outputs, which could then be measured to perform spectral studies. [ChISS is the Russian abbreviation for multichannel spectral seismometer. In this instrument the signal from the seismometer is passed through a system of narrow bandpass filters and recorded on photo paper. ChISS instruments have from 8 to 16 channels in the frequency range from 100 sec to 40 Hz. We used data mostly from 7 channels, ranging from 0.08 to 5 Hz.] Quantitative, pre-digital era investigations of high-frequency source scaling relied on this type of data. To augment data sets of central Central Asia explosions, we have measured and compiled 537 ChISS coda envelopes for 124 events recorded at Talgar, Kazakhstan, at a distance …

The propagation of an intense relativistic electron beam through a gas that is self-ionized by the beam's space charge and wakefields is examined analytically and with 3D particle-in-cell simulations. Instability arises from the coupling between a beam and the offset plasma channel it creates when it is perturbed. The traditional electron hose instability in a preformed plasma is replaced with this slower growth instability depending on the radius of the ionization channel compared to the electron blowout radius. A new regime for hose stable plasma wakefield acceleration is suggested.

The two-sided pyramid wavefront sensor has been extensively simulated in the direct phase mode using a wave optics code. The two-sided pyramid divides the focal plane so that each half of the core only interferes with the speckles in its half of the focal plane. A relayed image of the pupil plane is formed at the CCD camera for each half. Antipodal speckle pairs are separated so that a pure phase variation causes amplitude variations in the two images. The phase is reconstructed from the difference of the two amplitudes by transforming cosine waves into sine waves using the Hilbert transform. There are also other corrections which have to be applied in Fourier space. The two-sided pyramid wavefront sensor performs extremely well: After two or three iterations, the phase error varies purely in y. The two-sided pyramid pair enables the phase to be completely reconstructed. Its performance has been modeled closed loop with atmospheric turbulence and wind. Both photon noise and read noise were included. The three-sided and four-sided pyramid wavefront sensors have also been studied in direct phase mode. Neither performs nearly as well as does the two-sided pyramid wavefront sensor.