805 research outputs found
Geology for planning in St. Clair County, Illinois.
Cover title.At head of title: State of Illinois. Department of Registration and Education.Includes bibliographical references (pages 32-35)
Why citizens don’t like paying for public goods with their taxes– and how institutions can change that
Why are Americans so against paying taxes to fund basic government functions such as roads and education? In new research, Alan M. Jacobs and J. Scott Matthews find that many citizens object to paying for public investment because they do not trust politicians to spend new revenues as promised. Using online experiments with voting-age US citizens, they find that support for using taxation to pay for investment was dependent on how much voters trusted the institution charged with carrying out the work. Local governments and the military were trusted to a much greater degree than Congress, especially among conservatives. Citizens were also more willing to pay more for public goods when they were told that the new taxes would be set aside in a dedicated trust fund account
Method and apparatus for shadow aperture backscatter radiography (SABR) system and protocol
A shadow aperture backscatter radiography (SABR) system includes at least one penetrating radiation source for providing a penetrating radiation field, and at least one partially transmissive radiation detector, wherein the partially transmissive radiation detector is interposed between an object region to be interrogated and the radiation source. The partially transmissive radiation detector transmits a portion of the illumination radiation field. A shadow aperture having a plurality of radiation attenuating regions having apertures therebetween is disposed between the radiation source and the detector. The apertures provide illumination regions for the illumination radiation field to reach the object region, wherein backscattered radiation from the object is detected and generates an image by the detector in regions of the detector that are shadowed by the radiation attenuation regions
Radiography by selective detection of scatter field velocity components
A reconfigurable collimated radiation detector, system and related method includes at least one collimated radiation detector. The detector has an adjustable collimator assembly including at least one feature, such as a fin, optically coupled thereto. Adjustments to the adjustable collimator selects particular directions of travel of scattered radiation emitted from an irradiated object which reach the detector. The collimated detector is preferably a collimated detector array, where the collimators are independently adjustable. The independent motion capability provides the capability to focus the image by selection of the desired scatter field components. When an array of reconfigurable collimated detectors is provided, separate image data can be obtained from each of the detectors and the respective images cross-correlated and combined to form an enhanced image
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Detection of Subsurface Defects Using X-Ray Lateral Migration Radiography - A New Backscatter Imaging Technique
A new Compton X-ray backscatter imaging technique called lateral migration radiography (LMR) is applied to detecting a class of sub-surface defects in materials and structures of industrial importance. These include flaws and defects for which there is either no known method or an effective method for detection. Examples are delamination in layered composite structures, defects in deposited coatings on metal surfaces such as in aircraft jet engine components and geometrical structural/composition changes (e.g. due to corrosion) on the inside of shell-like components with only outside surface area access.Research efforts include: the construction of simulated flawed test objects on which experimental measurements are performed to establish LMR flaw detection capabilities; performance of Monte Carlo simulations of these measurements to assist in predicting optimum source-detector configurations and to help obtain a detailed understanding of the physics of lateral migration in small voids and how this impacts the resulting LMR image contrasts; the procurement of samples of materials of industrial importance with flaws and defects; the application of LMR to the detection of flaws and defects in these samples; the development of a multi-detector scanning system to provide for faster, more effective flaw detection; and a determination, for the types of samples examined, of the limits and capabilities of flaw detection using LMR.LMR imaging measurements on the machined samples showed that the optimum contrast in flaw-to-background signal intensity occurred at an X-ray energy of 75 kVp for the aluminum samples and at 35 kVp for the Delrin sample. Monte Carlo simulations and experimental measurements on the aluminum samples showed that LMR is capable of detecting defects down to the tens of microns range. Measurements on the aluminum samples also showed that LMR is capable of detecting relatively small composition variations; a 30 % difference in image intensity was observed for aluminum samples that had a few percent difference in trace iron and copper content.LMR scans on aircraft samples showed that LMR is very good at detecting corrosion. Intensity decreases of up to 25 to 30 % were observed in corroded areas relative to the intensities in clean areas. Especially significant were scans of samples performed with the clean or uncorroded side facing up. The corrosion on the opposite side of these {approx} 2 mm thick samples, where there was contact between the frame member and the aircraft skin, was clearly visible. This demonstrates that LMR is capable of picking up composition changes on the inside of shell-like components with only outside surface area access. Scans of other samples showed that LMR is capable of detecting small flaws on the inside of shell-like components with only outside surface area access. Cracks around a fastener hole that were {approx} 15 mm in length and no more than 0.25 mm in width were seen through the aircraft skin. Scans of aluminum honeycomb structure demonstrated that LMR is also capable of picking up internal defects that include regions of crushed core and areas of debonding
Method and Apparatus for Computed Imaging Backscatter Radiography
Systems and methods of x-ray backscatter radiography are provided. A single-sided, non-destructive imaging technique utilizing x-ray radiation to image subsurface features is disclosed, capable of scanning a region using a fan beam aperture and gathering data using rotational motion
From Dose to Response: In Vivo Nanoparticle Processing and Potential Toxicity
Adverse human health impacts due to occupational and environmental exposures to manufactured nanoparticles are of concern and pose a potential threat to the continued industrial use and integration of nanomaterials into commercial products. This chapter addresses the inter-relationship between dose and response and will elucidate on how the dynamic chemical and physical transformation and breakdown of the nanoparticles at the cellular and subcellular levels can lead to the in vivo formation of new reaction products. The dose-response relationship is complicated by the continuous physicochemical transformations in the nanoparticles induced by the dynamics of the biological system, where dose, bio-processing, and response are related in a non-linear manner. Nanoscale alterations are monitored using high-resolution imaging combined with in situ elemental analysis and emphasis is placed on the importance of the precision of characterization. The result is an in-depth understanding of the starting particles, the particle transformation in a biological environment, and the physiological response
A Two-Dimensional Model with Chiral Condensates and Cooper Pairs Having QCD-like Phase Structure
We describe how a generalization of the original Gross-Neveu model from U(N)
to O(N) flavor symmetry leads to the appearance of a pairing condensate at high
density, in agreement with the conjectured phenomenon of color
superconductivity in -dimensional QCD. Moreover, the model displays a
rich phase structure which closely resembles the one expected in two-flavor
QCD.Comment: 11 pages, 1 fugure, Presented at TMU-Yale Symposium on Dynamics of
Gauge Fields: An External Activity of APCTP, Tokyo, Japan, 13-15 Dec 199
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The Prevalence and Clinical Implications of Comorbid Back Pain in Shoulder Instability: A Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability Cohort Study.
Background:Understanding predictors of pain is critical, as recent literature shows that comorbid back pain is an independent risk factor for worse functional and patient-reported outcomes (PROs) as well as increased opioid dependence after total joint arthroplasty. Purpose/Hypothesis:The purpose of this study was to evaluate whether comorbid back pain would be predictive of pain or self-reported instability symptoms at the time of stabilization surgery. We hypothesized that comorbid back pain will correlate with increased pain at the time of surgery as well as with worse scores on shoulder-related PRO measures. Study Design:Cross-sectional study; Level of evidence, 3. Methods:As part of the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, patients consented to participate in pre- and intraoperative data collection. Demographic characteristics, injury history, preoperative PRO scores, and radiologic and intraoperative findings were recorded for patients undergoing surgical shoulder stabilization. Patients were also asked, whether they had any back pain. Results:The study cohort consisted of 1001 patients (81% male; mean age, 24.1 years). Patients with comorbid back pain (158 patients; 15.8%) were significantly older (28.1 vs 23.4 years; P < .001) and were more likely to be female (25.3% vs 17.4%; P = .02) but did not differ in terms of either preoperative imaging or intraoperative findings. Patients with self-reported back pain had significantly worse preoperative pain and shoulder-related PRO scores (American Shoulder and Elbow Surgeons score, Western Ontario Shoulder Instability Index) (P < .001), more frequent depression (22.2% vs 8.3%; P < .001), poorer mental health status (worse scores for the RAND 36-Item Health Survey Mental Component Score, Iowa Quick Screen, and Personality Assessment Screener) (P < .01), and worse preoperative expectations (P < .01). Conclusion:Despite having similar physical findings, patients with comorbid back pain had more severe preoperative pain and self-reported symptoms of instability as well as more frequent depression and lower mental health scores. The combination of disproportionate shoulder pain, comorbid back pain and mental health conditions, and inferior preoperative expectations may affect not only the patient's preoperative state but also postoperative pain control and/or postoperative outcomes
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