Design of catalytic monoliths for closed-cycle carbon dioxide lasers

Pulsed carbon dioxide (CO2) lasers have many applications in aeronautics, space research, weather monitoring and other areas. Full exploitation of the potential of these lasers in hampered by the dissociation of CO2 that occurs during laser operation. The development of closed-cycle CO2 lasers requires active CO-O2 recombination (CO oxidation) catalyst and design methods for implementation of catalysts in CO2 laser systems. A monolith catalyst section model and associated design computer program, LASCAT, are presented to assist in the design of a monolith catalyst section of a closed cycle CO2 laser system. Using LASCAT,the designer is able to specify a number of system parameters and determine the monolith section performance. Trade-offs between the catalyst activity, catalyst dimensions, monolith dimensions, pressure drop, O2 conversion, and other variables can be explored and adjusted to meet system design specifications. An introduction describes a typical closed-cycle CO2 system, and indicates some advantages of a closed cycle laser system over an open cycle system and some advantages of monolith support over other types of supports. The development and use of a monolith catalyst model is presented. The results of a design study and a discussion of general design rules are given

Development of neutron activation analysis procedures for the determination of oxygen in potassium final report, period ending 15 dec. 1964

Neutron activation analysis for determination of oxygen in potassiu

Numerical Model Derived Altimeter Correction Maps for Non-Standard Atmospheric Temperature and Pressure

Altimeter corrections for non-standard temperature pose a challenge because accurate calculations require detailed knowledge of the temperature structure of the atmosphere between the surface and the aircraft. By applying basic hypsometric formulae to high resolution numerical model temperature and moisture output, detailed maps of current and forecasted corrected D-values are created. Corrected D-values provide the altitude difference between the true altitude and the indicated altitude from a pressure altimeter. Unlike standard D-values, the corrected D-value corrects for non-standard pressure in addition to non-standard temperature and is therefore useful for flights below class A airspace. Maps of corrected D-value may help provide increased situational awareness for pilots during cold-weather operations as well as a useful educational tool for quantifying the effects of non-standard temperature on pressure altimetry

An experimental study of the flow variables at the minimum pressure station of ninety-degree pipe bends

Flow variables related to minimum pressure in circular pipe bend

How Generational Preferences, Cultural Trends, Workplace Expectations, and Other Factors Have Changed the Definition of Professionalism in Terms of Attire and How Employers and Managers Can Respond

Business attire is an essential part of personal branding as well as corporate branding activities. Fashion, cultural trends, workplace expectations play a role, among others form and change what an acceptable work attire is. Corporations even use their definitions of work attire in their advertising activities as a part of identity development. Such recent examples are State Farm Insurance, Progressive, and Enterprise Rent a Car. Observations during career development activities at multiple universities also revealed that Millennials might have different professional attire interpretations. The literature review indicated a gap regarding how perceptions change from generation to generation in this topic. In the paper, factors that may influence the definition of professional attire have been investigated for three groups of respondents, including early career, mid-career, and retired professionals. Grounded Theory methodology has been used. Multiple themes have been identified for the three generational groups. Further research implications have been discussed

Analysis of Causes of Icing Conditions Which Contributed to the Crash of Continental Flight 3407

On February 12, 2009, at 10:20 p.m. EST, Continental Connection Flight 3407 from Newark to Buffalo crashed 5 miles short of the runway at Buffalo, killing all 49 people on board and one person on the ground. The National Transportation Safety Board (NTSB) is still investigating the crash, but preliminary reports show the airplane was experiencing icing conditions before the crash. Preliminary reports indicate that the pilot did not respond properly to the icing conditions, which contributed to the crash. However, the presence of the icing conditions which were significant enough to cause aircraft problems needs further investigation to determine if pilots can be forewarned about these type of aircraft icing problems

The effect of chain length and conformation on the nucleation of glycine homopeptides during the crystallization process.

To explore the effect of chain length and conformation on the nucleation of peptides, the primary nucleation induction time of glycine homopeptides in pure water at different supersaturation levels under various temperatures has been determined. Nucleation data suggest that longer chains will prolong the induction time, especially for chains longer than three, where nucleation will occur over several days. In contrast, the nucleation rate increased with an increase in the supersaturation for all homopeptides. Induction time and nucleation difficulty increase at lower temperatures. However, for triglycine, the dihydrate form was produced with an unfolded peptide conformation (pPII) at low temperature. The interfacial energy and activation Gibbs energy of this dihydrate form are both lower than those at high temperature, while the induction time is longer, indicating the classical nucleation theory is not suitable to explain the nucleation phenomenon of triglycine dihydrate. Moreover, gelation and liquid-liquid separation of longer chain glycine homopeptides were observed, which was normally classified to nonclassical nucleation theory. This work provides insight into how the nucleation process evolves with increasing chain length and variable conformation, thereby offering a fundamental understanding of the critical peptide chain length for the classical nucleation theory and complex nucleation process for peptides

Radical Science Writing:An Interdisciplinary Book Arts Approach

The tenet of this article is that historic scientific works, along with science-themed artists’ books, photobooks, and U.S. government-produced reports, can contribute to contemporary science education in inspiring ways. By integrating these materials into undergraduate science-writing projects, we are pioneering an alternative paradigm that merges the sciences and the arts. We are teaching undergraduate science majors through content that invokes scientific curiosity, sparks creativity, and makes science accessible. Through handwritten and printed text, visual art, and artistic works, students learn how science has been communicated across the centuries. As in science education, we explore how students use the information resources made available to them by the teacher in the classroom and from other sources (in this case, two specialized library departments) to construct meanings, produce their own rhetorically shaped versions of entities and concepts, and present themselves as learners of science. Challenged within our respective disciplines and by our campus community, we engage students in a learning process deemed radical by our peers