Media Censures: The Hutchins Commission on the Press, the New York Intellectuals on Mass Culture

Around the middle of the 20th century, two groups of American intellectuals turned their attention to the mass media. The scholars on the Commission on Freedom of the Press, chaired by University of Chicago president Robert Maynard Hutchins, assessed the American news media. Dwight Macdonald and his fellow New York intellectuals assessed the American entertainment media and other forms of mass culture. On the whole, both groups were appalled. Hutchins et al. and Macdonald et al. inhabited different worlds—the intellectual establishment and the intellectual antiestablishment—yet the two groups developed parallel critiques. Comparing them reveals important aspects of the role of midcentury intellectuals, particularly their attitudes toward mass media and mass society, officialdom and power. It also raises provocative questions about the forces that shape research agendas

On the effects of junctions, bifurcations, heating and expansions on tube flows

Imperial Users onl

High performance sapphire windows

High-quality, wide-aperture optical access is usually required for the advanced laser diagnostics that can now make a wide variety of non-intrusive measurements of combustion processes. Specially processed and mounted sapphire windows are proposed to provide this optical access to extreme environment. Through surface treatments and proper thermal stress design, single crystal sapphire can be a mechanically equivalent replacement for high strength steel. A prototype sapphire window and mounting system have been developed in a successful NASA SBIR Phase 1 project. A large and reliable increase in sapphire design strength (as much as 10x) has been achieved, and the initial specifications necessary for these gains have been defined. Failure testing of small windows has conclusively demonstrated the increased sapphire strength, indicating that a nearly flawless surface polish is the primary cause of strengthening, while an unusual mounting arrangement also significantly contributes to a larger effective strength. Phase 2 work will complete specification and demonstration of these windows, and will fabricate a set for use at NASA. The enhanced capabilities of these high performance sapphire windows will lead to many diagnostic capabilities not previously possible, as well as new applications for sapphire

Sapphire Viewports for a Venus Probe

A document discusses the creation of a viewport suitable for use on the surface of Venus. These viewports are rated for 500 C and 100 atm pressure with appropriate safety factors and reliability required for incorporation into a Venus Lander. Sapphire windows should easily withstand the chemical, pressure, and temperatures of the Venus surface. Novel fixture designs and seals appropriate to the environment are incorporated, as are materials compatible with exploration vessels. A test cell was fabricated, tested, and leak rate measured. The window features polish specification of the sides and corners, soft metal padding of the sapphire, and a metal C-ring seal. The system safety factor is greater than 2, and standard mechanical design theory was used to size the window, flange, and attachment bolts using available material property data. Maintenance involves simple cleaning of the window aperture surfaces. The only weakness of the system is its moderate rather than low leak rate for vacuum applications

Enantiomer discrimination and ion receptors

Highly lipophilic α-, β- and γ- cyclodextrin derivatives were prepared in order to obtain enantiomer selective ionophores for β-aryl ammonium ions and selective ionophores for tetrahedral ammonium ions. The extent of cyclodextrin functionalisation and the homogeneity of the products was investigated by chemical depolymerisation, (^1)H and (^13)C NMR and (+)-FAB-, FD- and ES- mass spectral analysis. For each cyclodextrin, the products of alkylation were found to consist of several constitutional isomers and homologues. These highly lipophilic molecules were incorporated into solvent polymeric membranes and investigated as electrochemical sensors for chiral molecules incorporating an aryl ring. Electrodes using BBPA as the plasticizer were stable and well defined with a limit of detection for ephedrine of -log[c] = 6.5. Interference from serum levels of Na+, K+, Ca2+ and Mg2+ is minimal (-logK(^POT) = 3.9). The electrodes were highly enantioselective in binding ephedrine and closely related homologues. The mechanism of enantiomer discrimination was investigated by several multi-nuclear NMR techniques and the complexation process was investigated by ES-MS. Lipophilic per-O-octylated α-, β- and γ- cyclodextrins exhibit size selectivity and cation discrimination in the binding of +NH4, +NMe4 and +NEt4. Sensors based on per-O-octyl-β-cyclodextrin show excellent sensitivity and good selectivity for +NMe4 over metal cations and may be used for the detection of cationic surfactants. Complexation was studied in situ and competitively by ES-MS as well as by and relaxation time acquisition. The possibility of developing several chiral crown ether and cyclam based ionophores was also investigated

Dilemmas of Sustaining Parastatal Success: The Botswana Meat Commission

SUMMARY Parastatals typically receive little detailed treatment in studies of the African state, and are commonly regarded as failures. The experience of the Botswana Meat Commission, one instance of a highly successful state enterprise, is useful in revealing the complex contingencies involved in sustaining success in Africa. Debilitating environmental changes, costly efforts to secure a position in highly?prized markets, administrative bloat and institutional density have combined in recent years to make it increasingly difficult for this parastatal to fulfil its assigned political mission of serving the interests of Botswana's elite cattle owners. SOMMAIRE Typiquement les parastatals ne reçoivent guère d'attention dans les études de l'état africain, et sont normalement perçus comme des échecs. L'expérience de la Commission de la Viande du Botswana est un exemple d'une entreprise d'état très réussie, et se révèle tort utile afin de prévoir imprévus complexes impliqués dans la poursuite d'un succès en Afrique. Des changements environnementaux, des efforts coûteux afin de maintenir une position dans des marchés de hauts prix, une croissance de l'administration et une densité institutionelle, tous ces facteurs combinés ont rendu difficile, ces dernières années l'accomplissement de la mission politique de ce parastatal; celle de servir les intérêts de l'élite des propriétaires de bétail du Botswana. RESUMEN En general, las entidades paraestatales reciben un tratamiento poco acucioso en los estudios sobre el estado africano y frecuentemente son consideradas un fracaso. La experiencia de la Comisión de la Carne de Botswana, un ejemplo de empresa estatal altamente exitosa, es útil para revelar las complejas contingencias involucradas en la mantención del éxito en Africa. Los cambios ambientales debilitadores, los costosos esfuerzos para asegurarse un lugar en mercados altamente preciados, la hipertrofia administrativa y la densidad institucional, han conspirado en los años recientes para dificultar crecientemente el cumplimiento de la misión política asignada a esta entidad paraestatal de servir los intereses de la elite de propietarios ganaderos de Botswana

High Temperature Transparent Furnace Development

This report describes the use of novel techniques for heat containment that could be used to build a high temperature transparent furnace. The primary objective of the work was to experimentally demonstrate transparent furnace operation at 1200 C. Secondary objectives were to understand furnace operation and furnace component specification to enable the design and construction of a low power prototype furnace for delivery to NASA in a follow-up project. The basic approach of the research was to couple high temperature component design with simple concept demonstration experiments that modify a commercially available transparent furnace rated at lower temperature. A detailed energy balance of the operating transparent furnace was performed, calculating heat losses through the furnace components as a result of conduction, radiation, and convection. The transparent furnace shells and furnace components were redesigned to permit furnace operation at at least 1200 C. Techniques were developed that are expected to lead to significantly improved heat containment compared with current transparent furnaces. The design of a thermal profile in a multizone high temperature transparent furnace design was also addressed. Experiments were performed to verify the energy balance analysis, to demonstrate some of the major furnace improvement techniques developed, and to demonstrate the overall feasibility of a high temperature transparent furnace. The important objective of the research was achieved: to demonstrate the feasibility of operating a transparent furnace at 1200 C

A Gentle Introduction to Conformal Prediction and Distribution-Free Uncertainty Quantification

Black-box machine learning learning methods are now routinely used in high-risk settings, like medical diagnostics, which demand uncertainty quantification to avoid consequential model failures. Distribution-free uncertainty quantification (distribution-free UQ) is a user-friendly paradigm for creating statistically rigorous confidence intervals/sets for such predictions. Critically, the intervals/sets are valid without distributional assumptions or model assumptions, possessing explicit guarantees even with finitely many datapoints. Moreover, they adapt to the difficulty of the input; when the input example is difficult, the uncertainty intervals/sets are large, signaling that the model might be wrong. Without much work and without retraining, one can use distribution-free methods on any underlying algorithm, such as a neural network, to produce confidence sets guaranteed to contain the ground truth with a user-specified probability, such as 90%. Indeed, the methods are easy-to-understand and general, applying to many modern prediction problems arising in the fields of computer vision, natural language processing, deep reinforcement learning, and so on. This hands-on introduction is aimed at a reader interested in the practical implementation of distribution-free UQ who is not necessarily a statistician. We lead the reader through the practical theory and applications of distribution-free UQ, beginning with conformal prediction and culminating with distribution-free control of any risk, such as the false-discovery rate, false positive rate of out-of-distribution detection, and so on. We will include many explanatory illustrations, examples, and code samples in Python, with PyTorch syntax. The goal is to provide the reader a working understanding of distribution-free UQ, allowing them to put confidence intervals on their algorithms, with one self-contained document.Comment: Blog and tutorial video http://angelopoulos.ai/blog/posts/gentle-intro

Everyone loves select committees these days, but have they really changed?

The Wright reforms have been widely credited with reinvigorating select committees. Stephen Bates, Mark Goodwin (University of Birmingham) and Steve McKay (University of Lincoln) take issue with this assumption. They found the reforms have made little or no difference to MP turnover and attendance, which are driven by the parliamentary cycle. When MPs are jostling for payroll vote positions and trying to keep up with constituency duties and votes in the Chamber, select committees are likely to suffer