The Public Broadcasting Act: The Licensee Editorializing Ban and the First Amendment

This article contends that the public is deprived of an important source of information on public affairs issues as a result of the section 399(a) prohibition on editorializing. After an examination of the legislative history of Section 399(a), and the heritage of broadcast regulation in the United States, the article concludes that the prohibition on editorializing is an improper restriction on free expression in violation of the First Amendment

Software Engineering I: Teaching Challenges

The term software engineering can be traced to the late 1960s in response to large-scale, software development problems. Since then it has evolved as a discipline, both within industry and the academy. There have been distinct educational successes: “Standard practice” has matured (and found its way into more textbooks),the ACM and IEEE Computer Society have published curriculum guidelines, computer science programs commonly offer at least one software engineering course, and software engineering degrees (undergraduate or graduate) are more common. However, software engineering still presents a challenge. The term itself has become contorted by companies (and society in general); software has become far more diverse (along with the environments in which software engineers work); industrial software processes are not easily replicated in the classroom; what students are expected to know (once they are employed) has expanded significantly; software tools change rapidly (affecting student expectations); and the discipline involves far more than “good program-ming” (or a large programming project). This talk describes these challenges – and suggestions for dealing with them – in light of my 30 years teaching software engineering in a university

Water-Assisted Oxygen Activation During Selective Oxidation Reactions

The selective functionalization of hydrocarbons with oxygen to produce valuable commodity chemicals is inherently challenging, because of the thermodynamic stability of the complete combustion products. Emerging green synthesis routes and sustainable energy production also rely on the success of selective oxidation reactions. As one of the unselective by-products, water is always present under reaction conditions and numerous studies indicate that the catalytic activity and selectivity of selective oxidation reactions may be tuned by judiciously controlling the water content during the reaction. Some experimentally verified examples include the preferential oxidation of carbon monoxide, direct hydrogen peroxide synthesis, propene epoxidation and alcohol oxidation. Finally, it has been predicted that the direct conversion of methane to methanol can benefit from the right amount of water near the active site during oxygen activation

The Critical Role of Water at the Gold-titania Interface in Catalytic CO Oxidation

We provide direct evidence of a water-mediated reaction mechanism for room-temperature CO oxidation over Au/TiO2 catalysts. A hydrogen/deuterium kinetic isotope effect of nearly 2 implicates O-H(D) bond breaking in the rate-determining step. Kinetics and in situ infrared spectroscopy experiments showed that the coverage of weakly adsorbed water on TiO2 largely determines catalyst activity by changing the number of active sites. Density functional theory calculations indicated that proton transfer at the metal-support interface facilitates O2 binding and activation; the resulting Au-OOH species readily reacts with adsorbed Au-CO, yielding Au-COOH. Au-COOH decomposition involves proton transfer to water and was suggested to be rate determining. These results provide a unified explanation to disparate literature results, clearly defining the mechanistic roles of water, support OH groups, and the metal-support interface

Rapid probe of the nicotine spectra by high-resolution rotational spectroscopy

Nicotine has been investigated in the gas phase and two conformational forms were characterized through their rotational spectra. Two spectroscopic techniques have been used to obtain the spectra: a new design of broadband Fourier transform microwave (FTMW) spectroscopy with an in-phase/quadrature- phase-modulation passage-acquired-coherence technique (IMPACT) and narrowband FTMW spectroscopy with coaxially oriented beam-resonator arrangement (COBRA). The rotational, centrifugal distortion and hyperfine quadrupole coupling constants of two conformers of nicotine have been determined and found to be in N-methyl trans configurations with the pyridine and pyrrolidine rings perpendicular to one another. The quadrupole hyperfine structure originated by two 14N nuclei has been completely resolved for both conformers and used for their unambiguous identification. © 2011 the Owner Societies

NaBr Poisoning of Au/TiO\u3csub\u3e2\u3c/sub\u3e Catalysts: Effects on Kinetics, Poisoning Mechanism, and Estimation of the Number of Catalytic Active Sites

Sodium bromide was used to intentionally poison a commercial Au/TiO2 catalyst with the goals of understanding the nature of halide poisoning and evaluating the number and nature of the catalytic active sites. A series of eight poisoned catalysts were prepared by impregnating the parent catalyst with methanolic solutions of NaBr. Each catalyst was tested with CO oxidation catalysis under differential reactor conditions; O2 reaction orders and Arrhenius activation energies were determined for each material. All of the kinetic data, including a Michaelis−Menten analysis, indicated that the primary effect of adding NaBr was to reduce the number of catalytically active sites. Density functional theory calculations, employed to evaluate likely binding sites for NaBr, showed that NaBr binds more strongly to Au corner and edge atoms than it does to the titania support or to exposed Au face atoms. Infrared spectroscopy of adsorbed CO, along with a Temkin analysis of the data, was also used to evaluate changes to the catalyst upon NaBr deposition. These studies suggested that NaBr addition induces some subtle changes in the coverage dependent properties of CO adsorption, but that these did not substantially impact the CO coverage of the CO binding sites. The experimental and computational results are discussed in terms of possible poisoning mechanisms (siteblocking vs off-site binding and modification); the nature and number of active sites are also discussed in the context of the results