855 research outputs found
Ground calibration of the Silicon Drift Detectors for NICER
No full textThe Neutron star Interior Composition ExploreR (NICER) is set to be deployed on the International Space Station (ISS) in early 2017. It will use an array of 56 Silicon Drift Detectors (SDDs) to detect soft X-rays (0.2 - 12 keV) with 100 nanosecond timing resolution. Here we describe the effort to calibrate the detectors in the lab primarily using a Modulated X-ray Source (MXS). The MXS that was customized for NICER provides more than a dozen emission lines spread over the instrument bandwidth, providing calibration measurements for detector gain and spectral resolution. In addition, the fluorescence source in the MXS was pulsed at high frequency to enable measurement of the delay due to charge collection in the silicon and signal processing in the detector electronics. A second chamber, designed to illuminate detectors with either 55 Fe, an optical LED, or neither, provided additional calibration of detector response, optical blocking, and effectiveness of background rejection techniques. The overall ground calibration achieved total operating time that was generally in the range of 500-1500 hours for each of the 56 detectors. Keywords: Silicon Drift Detectors; X-rays; timing spectroscopy; calibrationUnited States. National Aeronautics and Space Administration (Contract NNG14PJ13C
Paley, William: science and rhetoric in his natural theology
No full textWilliam Paley's Natural Theology is probably the nineteenth century's most well- known design argument. As such an influential book, it is almost expected that twentieth century intellectual historians should at least pay a footnote to it. In midst of all these studies about the impact of Natural Theology upon the nineteenth century, one key fact is forgotten: Natural Theology and its sources were written in the eighteenth century. It is the goal of this thesis to demonstrate that Paley's design argument must be compared to the intellectual climate of that time period. Chapters 1 and 2 outline the rhetorical argument and the tools that Paley used to persuade his polite eighteenth century audience. The majority of scientific sources and examples he used were well-known names and therefore implicitly contributed to the believability of his argument. Accordingly, chapters 3 and 4 investigate why Paley's scientific sources added credibility to Natural Theology. Chapters 5 and 6 examine the actual scientific data that Paley turned into examples for his design argument. Setting the rhetoric aside, what was the actual scientific picture communicated by his examples? In these chapters, we find that even though Paley argues against random change, he does support a morphological telic change—the development of a supplemental part based on a pre-existing, fixed body part. As every chapter of this thesis unfolds, it will become more apparent that Paley was an intellectual heir to the eighteenth century. He wrote in a polite manner and employed a body of standard eighteenth century natural philosophical knowledge. It is this context that must be addressed and seriously considered when studying the nineteenth century intellectual legacy of Natural Theology
B-i-bi : b-ib-, b-o-bo, b-i-bitty-bi, etc.
No full textGift of Dr. Mary Jane Esplen.Piano guitar voice [instrumentation]F major [key]Bright Moderato [tempo]Popular song [form/genre]Photograph of Ray Bloch [illustration]Extra material (lyrics) on front inside cover [note]Publisher's advertisement on back cover [note
X-ray Emitting Hot Gas Production in Nearby Merging Galaxies
No full textUsing 8 micron infrared images from the Spitzer telescope we determine the half-light radius (the radius that contains half of the total light) for a sample of 49 nearby merging and merged pairs of galaxies. We compared this with other properties of the galaxies including a) the mass of X-ray emitting hot gas Mx(gas), b) the star formation rate (SFR), c) the large scale environment the galaxies reside in, and d) the chemical composition of the galaxies. Our goal is to better understand the processes that produce hot gas in galaxie
Using ACIS on the Chandra X-ray Observatory as a particle radiation monitor
No full textThe Advanced CCD Imaging Spectrometer (ACIS) is one of two focal-plane instruments on the Chandra X-ray Observatory. During initial radiation-belt passes, the exposed ACIS suffered significant radiation damage from trapped soft protons scattering off the x-ray telescope's mirrors. The primary effect of this damage was to increase the charge-transfer inefficiency (CTI) of the ACIS 8 front-illuminated CCDs. Subsequently, the Chandra team implemented procedures to remove the ACIS from the telescope's focus during high-radiation events: planned protection during radiation-belt transits; autonomous protection triggered by an on-board radiation monitor; and manual intervention based upon assessment of space-weather conditions. However, as Chandra's multilayer insulation ages, elevated temperatures have reduced the effectiveness of the on-board radiation monitor for autonomous protection. Here we investigate using the ACIS CCDs themselves as a radiation monitor. We explore the 10-year database to evaluate the CCDs' response to particle radiation and to compare this response with other radiation data and environment models.United States. National Aeronautics and Space Administration (NASA) (Contract NAS 8-37716)United States. National Aeronautics and Space Administration (NASA) (Contract NAS 8-38252
Birmingham News sleeve BN0044069
No full textRay Marshall / Secretary of Labor / Meeting with Alabama labor officials / Municipal airport / Conference due to be in Confernece Room B (2) on Concourse B - which runs between Eastern and Republican (old Southern). / Ray Marshall / Left / Secretary of Labor / Barney Weeks / President Alabama Labor Council (AFL-CIO) / [Work order included
Video as a Means to an End
No full textHaving teachers who can demonstrate and document teaching effectiveness, ethical behavior, professional obligations, and willingness to embrace continuous learning is important to for the well-being of the field. Video serves as a viable means of addressing these concerns. In particular, use of video in teacher training promotes a disposition for reflection on and documentation of emerging practice. It also serves to document transfer of classroom based knowledge into teaching even as it provides a tool for the documentation of growth across time. The chapter provides an outline of best practices in the use of video in teacher training, focusing on problems and techniques of video production that support quality recording and production of videos in class and in the field. Various categories of video appropriate for use in Teacher Training programs are addressed and examples of use are provided. Directions for getting started are provided along with a process for implementation using both hard and soft scaffolding
A Case Study Examining How Online Andragogy Has Reshaped Expectations for Face-to-Face Instruction
No full text
What are the effects of a culturally responsive pedagogy on the mathematics achievement and attitudes of sixth grade African American students in an urban school?, 1998
No full textThe objective of the study is to determine women and mens roles as defined by their society in the attainment of food security in Mali. The study examines how household female and male members share the burden of coping to achieve food security, as dictated by their cultural environment. Using the gender analysis approach and taking into account the shortcomings of the gender and development theoretical framework, this study looks into both male-female relationships in society and how they relate to food security. Four themes frame this inquiry: gender division of labor, income, expenditure patterns, and decision-making. They are analyzed in the context of four Malian villages concrete experience in dealing with seasonal food insecurity. These relations are examined in terms of production, distribution, consumption, and appropriation within the household. The study uses data collected through a structured questionnaire and informal interviews. The study revealed that men and women are assigned different but complementary responsibilities in providing food for the household. It is recommended that any policy that deals with food insecurity should consider the individuals of each gender in order to be successful
- …
