University of Houston

About: University of Houston is a education organization based out in Houston, Texas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 23074 authors who have published 53903 publications receiving 1641968 citations.

Properties of ceramic foam catalyst supports: pressure drop

Abstract: Ceramic foams are prepared as positive images of corresponding plastic structures and exhibit bed porosities as high as 80–90%. This makes them attractive as catalyst supports in processes where high pressure drop in the reactor tube is a problem. In this research, pressure drop relationships were examined for 10, 30, 45 and 65 pores per inch (PPI) ceramic foam samples made from 92.0 and 99.5% α-Al2O3 and from ZrO2 stabilized with Mg, Ca, and La2O3. Pore distributions were determined with imaging analysis, using digital techniques. Pressure drop measurements confirmed that ceramic foams follow the Forscheimer relationship and may be interpreted with the Ergun model, in which the pressure drop is the sum of viscous and inertial terms. The Ergun parameters, α and β, are not constant, α decreases from 8.05 to 2.88 and β increases from 0.0338 to 0.111 as the pore density increases from 10 to 65 PPI. Empirical equations were developed for these parameters in terms of the mean pore size and the bed porosity, and these indicated a dependence on the media properties. Calculated pressure drop from these equations were within 15% of measured values. Up to 15 wt.% γ-Al2O3 washcoat was added to 30 PPI samples of α-Al2O3 foams. Nitrogen BET surface areas increased from about 2 m2 g−1 in the unwashcoated samples to almost 15 m2 g−1 at the highest loading. Both α and β increase linearly with the BET surface area, α by only about 50% but β by a factor of 8. This suggests that roughness introduced by the washcoat plays a dominant role in the turbulent resistance.

Hunger Of Memory: The Education Of Richard Rodriguez

Abstract: Book Review: Richard Rodriguez Hunger of Memory Hunger of Memory, The Education of Richard Rodriguez Richard Rodriguez Interview with writer / journalist Richard Rodriguez, April 2011. Hunger of Memory by Richard Rodriquez book review An autobiography based on growing up in the US as a Mexican-American. Richard Rodriguez: 2014 National Book Festival Richard Rodriguez appears at the 2014 Library of Congress National Book Festival in Washington, D.C. Speaker Biography: ... Hunger of Memory Summary Project No rights involved on my behalf. An American Life Statistics, dates, and iconic images tell one story about a country. But to catch the subtleties and the spirit of a country, individual ... Excerpt from Richard Rodriguez's Hunger of Memory read by Ryan Morris Excerpt from Richard Rodriguez's Hunger of Memory read by Ryan Morris. Feats of memory anyone can do | Joshua Foer http://www.ted.com There are people who can quickly memorize lists of thousands of numbers, the order of all the cards in a ... Hunger of Memory Project Scheme Navarro Hunger Of Memory SchemeMusic Hunger of Memory (produced by Custom and Serious) SchemeMusic Hunger of Memory (produced by Custom ... How to triple your memory by using this trick | Ricardo Lieuw On | TEDxHaarlem Do you recall studying for your exams? You probably do. But do you remember how you studied, how you memorized French ... Want to improve your memory-Do this everyday | Krishan Chahal | TEDxMMUSadopurAmbala Most of us feel that our memory is weak. But how to improve your memory? From day to day life activity to memorized pie value ... How to learn any language in six months | Chris Lonsdale | TEDxLingnanUniversity Never miss a talk! SUBSCRIBE to the TEDx channel: http://bit.ly/1FAg8hB

Copper-catalyzed arylation and alkenylation of polyfluoroarene C-H bonds.

Abstract: An efficient, copper-catalyzed method for the arylation, alkenylation, and benzylation of polyfluoroarenes has been developed. Arenes containing two or more fluorine substituents on the aromatic ring can be efficiently functionalized. The best results are obtained by using a combination of copper iodide catalyst, phenanthroline ligand, aryl bromide or aryl iodide coupling partner, and DMF or DMF/xylene mixed solvent.

Inverse scattering series and seismic exploration

Abstract: This paper presents an overview and a detailed description of the key logic steps and mathematical-physics framework behind the development of practical algorithms for seismic exploration derived from the inverse scattering series. There are both significant symmetries and critical subtle differences between the forward scattering series construction and the inverse scattering series processing of seismic events. These similarities and differences help explain the efficiency and effectiveness of different inversion objectives. The inverse series performs all of the tasks associated with inversion using the entire wavefield recorded on the measurement surface as input. However, certain terms in the series act as though only one specific task, and no other task, existed. When isolated, these terms constitute a task-specific subseries. We present both the rationale for seeking and methods of identifying uncoupled task-specific subseries that accomplish: (1) free-surface multiple removal; (2) internal multiple attenuation; (3) imaging primaries at depth; and (4) inverting for earth material properties. A combination of forward series analogues and physical intuition is employed to locate those subseries. We show that the sum of the four task-specific subseries does not correspond to the original inverse series since terms with coupled tasks are never considered or computed. Isolated tasks are accomplished sequentially and, after each is achieved, the problem is restarted as though that isolated task had never existed. This strategy avoids choosing portions of the series, at any stage, that correspond to a combination of tasks, i.e., no terms corresponding to coupled tasks are ever computed. This inversion in stages provides a tremendous practical advantage. The achievement of a task is a form of useful information exploited in the redefined and restarted problem; and the latter represents a critically important step in the logic and overall strategy. The individual subseries are analysed and their strengths, limitations and prerequisites exemplified with analytic, numerical and field data examples.