Evaluation of the results of a round robin analysis for oxygen in potassium and sodium

Evaluation of various laboratory determination of oxygen in potassium and sodiu

“Too Tedious to Mention”: Pondering the Border, Black Atlantic, and Public Schooling in Colonial Canada

An advertisement for a “Negro man and boy” and “a variety of other articles too tedious to mention” for disposal” inspired this author to examine the “truly impossible, futile position for most black parents” in eighteenth and nineteenth century Canada. This article first examines how slaves were sold in a similar manner on both sides of the border by addressing the “many meanings of the border” to those involved with black migration in Canada. It then then examines a history of public schooling violence and legal case studies to evaluate the realities of those who faced “de facto practices of racial discrimination” when seeking an emancipated education for black families. By centering the realities evident in advertisements for slaves and public-school violence, I consider how Canadians were involved in the British Atlantic world slave trade and contributed to “an ongoing global project of subjugation and dispersal of African and African-descended peoples” by focusing on how racial public-school segregation responded to large-scale arrivals of black free and enslaved peoples in the late eighteenth and early to mid nineteenth centuries

Feasibility study of tungsten as a diffusion barrier between nickel-chromium-aluminum and Gamma/Gamma prime - Delta eutectic alloys

Coating systems proposed for potential use on eutectic alloy components in high-temperature gas turbine engines were studied with emphasis on deterioration of such systems by diffusion. A 1-mil thick W sheet was placed between eutectic alloys and a NiCrAl layer. Layered test specimens were aged at 1100 C for as long as long as 500 hours. Without the W barrier, the delta phase of the eutectic deteriorated by diffusion of Nb into the NiCrAl. Insertion of the W barrier stopped the diffusion of Nb from delta. Chromium diffusion from the NiCrAl into the gamma/gamma prime phase of the eutectic was greatly reduced by the barrier. However, the barrier thickness decreased with time; and W diffused into both the NiCrAl and the eutectic. When the delta platelets were alined parallel to the NiCrAl layer, rather than perpendicular, diffusion into the eutectic was reduced

Does Scenario Planning Have a Role in U.S. Graduate Business Schools’ Curriculum?

The literature reports scenario planning is increasingly being used by businesses to help plan more effectively. A potential problem with the existing scenario planning teaching models is they do not appear to support or benefit from scholarly research and practitioners’ action research. The research study rationale is described in detail as well as survey activity in the top rated 100 graduate business schools in the U.S. and also survey participants’ responses. The study, due to a low survey response rate, failed to provide adequate data to answer the study’s primary question. Limitations, recommendations for future research and conclusions are provided

Synergistic erosion/corrosion of superalloys in PFB coal combustor effluent

Two Ni-based superalloys were exposed to the high velocity effluent of a pressurized fluidized bed coal combustor. Targets were 15 cm diameter rotors operating at 40,000 rpm and small flat plate specimens. Above an erosion rate threshold, the targets were eroded to bare metal. The presence of accelerated oxidation at lower erosion rates suggests erosion/corrosion synergism. Various mechanisms which may contribute to the observed oxide growth enhancement include erosive removal of protective oxide layers, oxide and subsurface cracking, and chemical interaction with sulfur in the gas and deposits through damaged surface layers

Erosion/corrosion of turbine airfoil materials in the high-velocity effluent of a pressurized fluidized coal combustor

Four candidate turbine airfoil superalloys were exposed to the effluent of a pressurized fluidized bed with a solids loading of 2 to 4 g/scm for up to 100 hours at two gas velocities, 150 and 270 m/sec, and two temperatures, 730 deg and 795 C. Under these conditions, both erosion and corrosion occurred. The damaged specimens were examined by cross-section measurements, scanning electron and light microscopy, and X-ray analysis to evaluate the effects of temperature, velocity, particle loading, and alloy material. Results indicate that for a given solids loading the extent of erosion is primarily dependent on gas velocity. Corrosion occurred only at the higher temperature. There was little difference in the erosion/corrosion damage to the four alloys tested under these severe conditions

The erosion/corrosion of small superalloy turbine rotors operating in the effluent of a PFB coal combustor

Superalloy turbine rotors in a single stage turbine with 6 percent partial admittance were operated in the effluent of a pressurized fluidized bed coal combustor for up to 164 hours. Total mass flow was 300 kg/hr and average particulate loadings ranged from 600 to 2800 ppm for several coal/sorbent combinations. A 5.5 atm turbine inlet gas pressure and inlet gas temperatures from 700 to 800 C yielded absolute gas velocities at the stator exit of about 500 m/s. The angular rotation speed (40,000 rpm) of the six inch diameter rotors was equivalent to a tip speed of about 300 m/s, and average gas velocities relative to the rotating surface ranged from 260 to 330 m/s at mean radius. The rotor erosion pattern reflects heavy particle separation with severe (5 to 500 cm/yr) erosion at the leading edge, pressure side center, and suction side trailing edge at the tip. The erosion distribution pattern provides a spectrum of erosion/oxidation/deposition as a function of blade position. This spectrum includes enhanced oxidation (10 to 100 x air), mixed oxides in exposed depletion zones, sulfur rich oxides in deposition zones, and rugged areas of erosive oxide removal

Advancing Automated Methods for Microrna Profiling

The widespread influence of miRNAs in many biological processes and characteristic changes in expression profiles make them potential biomarkers for a range of diseases. With recent discoveries highlighting the enrichment of particular circulating miRNAs in plasma under pathological conditions, there has been a push for technological advances in miRNA profiling studies as a diagnostic tool. A standardized, automated, high-throughput method for miRNA isolation from human plasma samples was developed in this study. Samples were subject to full miRNome profiling utilizing RT-qPCR. These unique findings demonstrate that developing a distinct miRNA biomarker profile for heart failure patients is feasible and holds potential diagnostic value

Analysis of pre-residency research productivity, dual degree status, and gender distribution of underrepresented minorities among a current United States radiation oncology junior resident class

Background: Among the most competitive medical subspecialties, representation of underrepresented minorities (African-American race and/or Hispanic ethnicity) among resident trainees has historically been low compared to their United States Census general population representation. Research productivity and dual degree status may impact residency applicant competitiveness. To date, such an analysis has yet to be performed in Radiation Oncology. Methods: A list of radiation oncology residents from the graduating class of 2022 was obtained through internet searches. Demographics included were gender and dual degree status. Research productivity was calculated using the number of pre-residency peer-reviewed publications (PRP). Fisher's exact test was used for statistical analysis. Results: Of the 179 residents evaluated from the 2022 class, eleven (6.1%) were underrepresented minorities. Compared to the remainder of the class, underrepresented minorities had a lower proportion of men (63.6% versus 69.3%), a higher proportion of dual degrees (45.5% versus 28.6%), and a lower proportion of MD-PhD degrees (9.1% versus 17.2%). Underrepresented minorities had a higher proportion of residents with at least two PRP (72.7% versus 57.1%) and a lower proportion of residents with no PRP (18.2% versus 24.4%). None of these differences reached statistical significance (p > 0.05). Conclusion: Underrepresented minorities were comparable to the remainder of their Radiation Oncology resident class regarding gender distribution, dual degrees status, and likelihood of having at least two peer-reviewed publications cited in PubMed during the calendar year of residency application. Further studies will be needed to determine how these findings translate into future scholarly activity and post-graduate career choice