A Catalog of Digital Images of 113 Nearby Galaxies

We present a digital catalog of images of 113 galaxies in this paper. These galaxies are all nearby, bright, large and well resolved. All images were recorded with charge coupled devices (CCDs) at the Palomar Observatory with the 1.5 meter telescope and at the Lowell Observatory with the 1.1 meter telescope. At Palomar we used the Thuan--Gunn g, r and i photometric bands to take 3 images each of 31 spiral galaxies; at Lowell we used the B_J and R bands (2 images per galaxy) of the photometric system by Gullixson et al. (1995) to observe 82 spirals and ellipticals. The galaxies were selected to span the Hubble classification classes. All data are photometrically calibrated with foreground stars removed. Important data on these galaxies published in the "Third Reference Catalog of Bright Galaxies" (RC3) are recorded in the FITS file headers. All files are available through anonymous FTP from ftp://astro.princeton.edu/, through WWW at http://astro.princeton.edu/~frei/galaxy_catalog.html, and Princeton University Press will soon publish the data on CD-ROM.Comment: uuencoded compressed tar archive of postscript files (paper + 2 tables + 7 figures) Accepted for publication in the Astronomical Journa

Effects of nacelle shape on drag and weight of a supersonic cruising aircraft

The quantitive relationship of cruise drag and nacelle shape was investigated for a representative advanced supersonic transport configuration. Nacelle shape parameters were systematically varied, and the effects of these variations on wave and friction drag were determined. The effects of changes in vehicle drag, propulsion weight, and specific fuel consumption on vehicle takeoff gross weight were computed. Generally, it was found that nacelle shapes such that the maximum cross-sectional area occurred at or near the nozzle exit resulted in the lowest wave drag. In fact, nacelle shapes were found that produce favorable interference effects (drag reduction) of such magnitude as to nearly offset the friction drag of the nacelle

MS

thesisMany ergonomists strive to find links between physical risk factors and injuries in the workplace. To accomplish this, workers are observed in the workplace as they complete their daily jobs and an analysis is performed in real time. An alternative to this type of analysis is to record the workers completing their jobs using video cameras and then later perform a more in depth analysis. Although video analysis provides many benefits, it can be very time consuming and quite monotonous. Some jobs take many hours, even multiple days to analyze using video analysis techniques. Therefore, in order to be more efficient and save time, the following method was tested. The method included analyzing one representative cycle of the elements that were completed many times throughout each job. Once the representative element was analyzed, it was used for each instance that the specific element occurred resulting in a "built job." This greatly reduced the time of analysis since the element was only analyzed one time rather than the multiple times that it occurred in the representative job cycle. This led to a substantial time savings while still obtaining a reliable analysis and representation of the job of interest. Two analytical methods were used to compare the data between the fully analyzed job and the built job. The first was a basic comparison of averages, standard deviations and percent differences. The second was an intraclass correlation coefficient

Synthesis, Characterization, and Photophysical Properties of Scs Bis(N-Heterocyclic Thione) (Nht) Pd and Pt Complexes

The use of OLEDs (organic light-emitting diodes) in display screens has become increasingly popular due to their improved energy efficiency, relatively low cost, and minimized generation of heat. For these devices, emitters with high photostabilities are desired and efforts in developing molecules of this caliber are increasing rapidly. In the work presented, treatment of an aryl-bridged, bis(N-heterocyclic thione) (NHT) pincer ligand precursor with [PdCl2(CH3CN)2] or PtCl2 yielded 6,6used ring, SCS-NHT Pd and Pt pincer complexes, which are stable in the presence of air. These complexes were found to have excellent photostabilities of 96 % and 93% retention of emission intensity, which make these complexes good candidates for uses in OLEDs. X-ray crystallography of the complexes, computational studies, and the catalytic activity of the SCS-NHT Pd complex are also reported. With advancements in photoluminescent compounds such as these, more energy-efficient display screens can be developed, reducing electricity costs world-wide

An Expert System for Unit Commitment

Methods used to solve the unit commitment problem of power generating systems should give a solution which is both feasible and optimal, and should be flexible enough to be rapidly and easily reimplemented in response to a changing and unpredictable environment. An expert system is proposed which incorporates both heuristic and numerical optimization methods to achieve such a solution. The expert system acts like a preprocessor for data which is to be used by a Dynamic Programming routine to determine the most economical schedule of generating units. After the schedule has been generated, the expert system acts like a postprocessor to check the feasibility of the schedule and make recommendations for changes to achieve a better schedule

Le onde dell’educazione: l’espandersi come metafora nell’opera di Walter Benjamin

This paper draws upon the recent turn toward the early writings of Walter Benjamin on education to make two interventions. First, it suggests that understanding education as awakening in the existing Benjaminian scholarship is only partially correct. A more basic phenomenon that acts as the condition for the possibility of awakening is the movement of swelling. The paper then charts the various ways in which Benjamin discusses education and youth in relation to swellings and exaggerations. Second, the paper uses this insight to reevaluate several discussions within current educational philosophy including the takenfor- granted primacy of the relationship between student and teacher and the fraught relationship between education and politics.L’articolo prende in considerazione la recente attenzione ricevuta dagli scritti giovanili di Walter Benjamin dedicati all’educazione, al fine di realizzare due operazioni. In primo luogo, avanza l’ipotesi che l’interpretazione dell’educazione come “risveglio”, presente nella letteratura beniaminiana, sia solo parzialmente corretta. Un fenomeno più essenziale agisce come condizione di possibilità del risveglio, e consiste nel movimento dell’espansione. Si dà conto in seguito delle differenti modalità impiegate da Benjamin per esaminare l’educazione e la gioventù in relazione alle “espansioni” e alle “esagerazioni”. In secondo luogo, l’articolo sviluppa queste intuizioni per riconsiderare il dibattito presente nella filosofia dell’educazione attuale, incluso il primato, dato per acquisito, della relazione tra studente e insegnante, e la travagliata relazione tra educazione e politiche educative

Association of inferior vena cava filter placement for venous thromboembolic disease and a contraindication to anticoagulation with 30-day mortality

Importance: Despite the absence of data from randomized clinical trials, professional societies recommend inferior vena cava (IVC) filters for patients with venous thromboembolic disease (VTE) and a contraindication to anticoagulation therapy. Prior observational studies of IVC filters have suggested a mortality benefit associated with IVC filter insertion but have often failed to adjust for immortal time bias, which is the time before IVC filter insertion, during which death can only occur in the control group. Objective: To determine the association of IVC filter placement with 30-day mortality after adjustment for immortal time bias. Design, Setting, and Participants: This comparative effectiveness, retrospective cohort study used a population-based sample of hospitalized patients with VTE and a contraindication to anticoagulation using the State Inpatient Database and the State Emergency Department Database, part of the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality, from hospitals in California (January 1, 2005, to December 31, 2011), Florida (January 1, 2005, to December 31, 2013), and New York (January 1, 2005, to December 31, 2012). Data analysis was conducted from September 15, 2015, to March 14, 2018. Exposure: Inferior vena cava filter placement. Main Outcomes and Measures: Multivariable Cox proportional hazard models were constructed with IVC filters as a time-dependent variable that adjusts for immortal time bias. The Cox model was further adjusted using the propensity score as an adjustment variable. Results: Of 126 030 patients with VTE, 61 281 (48.6%) were male and the mean (SD) age was 66.9 (16.6) years. In this cohort, 45 771 (36.3%) were treated with an IVC filter, whereas 80 259 (63.7%) did not receive a filter. In the Cox model with IVC filter status analyzed as a time-dependent variable to account for immortal time bias, IVC filter placement was associated with a significantly increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P \u3c .001). When the propensity score was included in the Cox model, IVC filter placement remained associated with an increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P \u3c .001). Conclusions and Relevance: After adjustment for immortal time bias, IVC filter placement was associated with increased 30-day mortality in patients with VTE and a contraindication to anticoagulation. Randomized clinical trials are needed to determine the efficacy of IVC filter placement in patients with VTE and a contraindication to anticoagulation

Instrumentation of sampling aircraft for measurement of launch vehicle effluents

An aircraft was selected and instrumented to measure effluents emitted from large solid propellant rockets during launch activities. The considerations involved in aircraft selection, sampling probes, and instrumentation are discussed with respect to obtaining valid airborne measurements. Discussions of the data acquisition system used, the instrument power system, and operational sampling procedures are included. Representative measurements obtained from an actual rocket launch monitoring activity are also presented

An Assessment of the Air Force’s Return on Investment for Product Support Business Case Analysis Processes

There have been many fiscal challenges over the years facing the Department of Defense (DOD). With these challenges, cost savings initiatives have become commonplace. To meet these fiscal challenges head-on, new policies to improve estimating and control costs have been implemented. Senior leaders within the cost analysis community are tasked with managing these changes while continuing to provide timely and accurate cost estimates. The purpose of this research is to focus on one of the more important cost savings initiatives -- Product Support Business Case Analyses (PS-BCA). Our research questions explore the current cost and impact of this DoD cost saving policy using a mixed methods approach using both quantitative and qualitative data. The quantitative data showed significant improvements in the process in conducting PS-BCA’s as they became more standardized after 2016 however, despite this, 60% of programs showed a negative return on investment should their recommendations get implemented. Furthermore the qualitative data collected showed significant concerns regarding the PS-BCA process and that there is a belief that the Air Force is receiving suboptimal ROI in this process. These results were then used to answer our research questions to address these concerns and to also make policy recommendations to improve the PS-BCA process. Our results may assist senior leaders within the cost analysis career field in their decision making and also may be a useful starting point for future research