Dissociation phenomena in electron-beam sustained carbon dioxide lasers

A number of applications are emerging requiring efficient, long pulse, long-life sealed CO2 lasers. Examples include the proposed NASA and ESA wind lidars. Electron-beam sustained discharge devices are strong contenders. Unlike self-sustained discharges, e-beam sustenance readily provides efficient performance from large volume discharges and offers pulse lengths well in excess of the microsecond or so generally associated with self-sustained devices. In the case of the e-beam sustained laser, since the plasma is externally maintained and operated at electric field strengths less than that associated with the glow to arc transition, the discharges can be run even in the presence of strongly attacking species such as O2. Build up of large levels of attacking contaminants is nevertheless undesirable as their presence reduces the current drawn by the plasma and thus the pumping rate to the upper laser level. The impedance rise leads to a mismatch of the pulse forming network with a consequent loss of control over energy deposition, operating E/N, and gain. Clearly CO2 dissociation rates, the influence of dissociation products on the discharge and gain, and tolerance of the discharge to these products need to be determined. This information can then be used to assess co-oxidation catalyst requirements for sealed operation

The Unheard Stories of Former San Antonio Slaves

While the end of slavery in America was a huge step to provide equality to all, the livelihood of former slaves after the Civil War took many different paths, some of those paths ended up in San Antonio, Texas

Restorative practice and behaviour management in schools: discipline meets care.

The history of restorative practices in New Zealand schools is directly related to projects such as the Suspension Reduction Initiative (SRI) and the more recent Student Engagement Initiative (SEI); thus the origins of restorative practices in schools are linked with behaviour management and school discipline. During the same period, teachers' work has become more complex: They are working with an increasingly diverse range of students, which in turn requires epistemologically diverse teaching and relationship-building approaches to ensure maximum participation for all. Teachers are looking for new and better ways to interact with students in their classrooms, and those responsible for disciplinary systems are looking to restorative practice for new ways to resolve the increasing range and number of difficulties between teachers and students, students and other students, and between the school and parents. Restorative practices (RP) are currently seen as a way of achieving all this, so they carry a huge burden of hope. Relationship skills are a key competency in the new curriculum, and the philosophy of restoration offers both a basis for understanding and a process for putting this agenda into practice. In effect, it means educating for citizenship in a diverse world, including teaching the skills of conflict resolution. If we accept this philosophy, the curriculum for teacher education will require significant changes in what students are taught about behaviour and classroom management

Scientific Futures for a Rhetoric of Science: "We do this and they do that?" A Junior-Senior Scholar Session, RSA 2018, Minneapolis, Minnesota, USA; 1 June 2018

Growing attention to a rift between epistemology and ontology, between words and things, sets new challenges and invigorations for a Rhetoric of Science that traditionally aims to “analyze and evaluate the persuasive communications of scientists” (Ceccarelli, 2017, para 6). Rhetoricians confront a vibrant, new intellectual space where scholars across disciplines are seeking to better account for bodies and moving to “include the materiality of our ambient environs” in their analyses (Rickert, 2013, p. x). The question, in light of material expansions, is what is a Rhetoric of Science, and what are its futures? In response to the Rhetoric Society of America’s 2018 conference call for junior and senior scholars to discuss “major developments in rhetorical studies,” we offer a Feyerabendian innovation-meets-dogma performative session: the junior scholar, representing innovation, argues that Rhetoric of Science must move aggressively beyond a study of texts and scientific language to account for continuous technological, social, and biological entanglements; specifically, to expand the field’s practices to include neuro-cognitive approaches and other forms of experiment. The senior scholar, representing dogma, expresses caution, arguing that the domain of a Rhetoric of Science is still symbols and semiosis; specifically, that looking at “ambient rhetorics” and “entanglements” is another approach, not a foundational shift

Status of the KTeV Experiment at Fermilab

The KTeV experiment is a fixed target experiment at Fermilab. Its primary goal is the search for direct CP violation in the decay of neutral kaons. Its current status and some preliminary results will be discussed.Comment: 5 pages Latex, 4 figures; to be published in the proceedings of the XVI International Workshop on Weak Interactions and Neutrinos, WIN '97, Capri, Italy, June 22-28, 199

Dual-purpose self-deliverable lunar surface PV electrical power system

A safe haven and work supported PV power systems on the lunar surface will likely be required by NASA in support of the manned outpost scheduled for the post-2000 lunar/Mars exploration and colonization initiative. Initial system modeling and computer analysis shows that the concept is workable and contains no major high risk technology issues which cannot be resolved in the circa 2000 to 2025 timeframe. A specific selection of the best suited type of electric thruster has not been done; the initial modeling was done using an ion thruster, but Rocketdyne must also evaluate arc and resisto-jets before a final design can be formulated. As a general observation, it appears that such a system can deliver itself to the Moon using many system elements that must be transported as dead payload mass in more conventional delivery modes. It further appears that a larger power system providing a much higher safe haven power level is feasible if this delivery system is implemented, perhaps even sufficient to permit resource prospecting and/or lab experimentation. The concept permits growth and can be expanded to include cargo transport such as habitat and working modules. In short, the combined payload could be manned soon after landing and checkout. NASA has expended substantial resources in the development of electric propulsion concepts and hardware that can be applied to a lunar transport system such as described herein. In short, the paper may represent a viable mission on which previous investments play an invaluable role. A more comprehensive technical paper which embodies second generation analysis and system size will be prepared for near-term presentation

Evaluating Sweat Gland Activity with Imprint Techniques

Starch-iodine and bromphenol blue are standard indicators used to record the distribution and number of actively secreting sweat glands. In this report, techniques employing these indicators were compared with methods utilizing newer plastic and silicone impressions.1. Both the plastic and silicone impressions yielded consistently greater sweat gland droplet counts than either of the indicators (p < 0.01).2. A simple technique applying thin films of a silicone rubber monomer to obtain sharp, permanent and uniformly reproducible sweat droplet impressions with little technical skill was judged superior to all methods evaluated

CMS search plans and sensitivity to new physics with dijets

CMS will use dijets to search for physics beyond the standard model during early LHC running. The inclusive jet cross section as a function of jet transverse momentum, with 10 inverse picobarns of integrated luminosity, is sensitive to contact interactions beyond the reach of the Tevatron. The dijet mass distribution will be used to search for dijet resonances coming from new particles, for example an excited quark. Additional sensitivity to the existence of contact interactions or dijet resonances can be obtained by comparing dijet rates in two distinct pseudorapidity regions.Comment: 10 pages, 4 figures, accepted for publication in J. Phys. G: Nucl. Part. Phy