1,086 research outputs found

    Preliminary Report on the Behavior of U-Pb Zircon and K-Ar Systems in Polymetamorphosed Ophiolitic Rocks and Batholithic Rocks, Southwestern Sierra Nevada Foothills, California

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    Ophiolitic rocks of the southwest Sierra Nevada foothills form part of the western metamorphic wall of the Sierra Nevada batholith (fig. 1). Geochronological studies were undertaken to determine: (1) The igneous petrogenetic age of the ophiolite; (2) The age of a prebatholith dynamic greenschist to amphibolite facies metamorphic event experienced by the ophiolite; and (3) The emplacement ages of the batholithic rocks. Geochronological work was interfaced with detailed structural and petrologic studies. A summary of the geochronological data is given in figure 2

    Infrared Camera Characterization of Bi-Propellant Reaction Control Engines during Auxiliary Propulsion Systems Tests at NASA's White Sands Test Facility in Las Cruces, New Mexico

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    This paper describes the application of a FUR Systems A40M infrared (IR) digital camera for thermal monitoring of a Liquid Oxygen (LOX) and Ethanol bi-propellant Reaction Control Engine (RCE) during Auxiliary Propulsion System (APS) testing at the National Aeronautics & Space Administration's (NASA) White Sands Test Facility (WSTF) near Las Cruces, New Mexico. Typically, NASA has relied mostly on the use of ThermoCouples (TC) for this type of thermal monitoring due to the variability of constraints required to accurately map rapidly changing temperatures from ambient to glowing hot chamber material. Obtaining accurate real-time temperatures in the JR spectrum is made even more elusive by the changing emissivity of the chamber material as it begins to glow. The parameters evaluated prior to APS testing included: (1) remote operation of the A40M camera using fiber optic Firewire signal sender and receiver units; (2) operation of the camera inside a Pelco explosion proof enclosure with a germanium window; (3) remote analog signal display for real-time monitoring; (4) remote digital data acquisition of the A40M's sensor information using FUR's ThermaCAM Researcher Pro 2.8 software; and (5) overall reliability of the system. An initial characterization report was prepared after the A40M characterization tests at Marshall Space Flight Center (MSFC) to document controlled heat source comparisons to calibrated TCs. Summary IR digital data recorded from WSTF's APS testing is included within this document along with findings, lessons learned, and recommendations for further usage as a monitoring tool for the development of rocket engines

    A biomechanical analysis of the stand-up paddle board stroke: A comparative study

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    Background: Stand-up paddle boarding (SUP) is a rapidly growing global aquatic sport, with increasing popularity among participants within recreation, competition and rehabilitation. To date, few scientific studies have focused on SUP. Further, there is no research examining the biomechanics of the SUP paddle stroke. The purpose of this study was to investigate whether variations in kinematics existed among experienced and inexperienced SUP participants using three-dimensional motion analysis. This data could be of significance to participants, researchers, coaches and health practitioners to improve performance and inform injury minimization strategies. Methods: A cross-sectional observational design study was performed with seven experienced and 19 inexperienced paddlers whereby whole-body kinematic data were acquired using a six-camera Vicon motion capture system. Participants paddled on a SUP ergometer while three-dimensional range of motion (ROM) and peak joint angles were calculated for the shoulders, elbows, hips and trunk. Mann-Whitney U tests were conducted on the non-normally distributed data to evaluate differences between level of expertise. Results: Significant differences in joint kinematics were found between experienced and inexperienced participants, with inexperienced participants using greater overall shoulder ROM (78.9° ± 24.9° vs 56.6° ± 17.3°, p = 0.010) and less hip ROM than the experienced participants (50.0° ± 18.5° vs 66.4° ± 11.8°, p = 0.035). Experienced participants demonstrated increased shoulder motion at the end of the paddle stoke compared to the inexperienced participants (74.9° ± 16.3° vs 35.2° ± 28.5°, p = 0.001 minimum shoulder flexion) and more extension at the elbow (6.0° ± 9.2° minimum elbow flexion vs 24.8° ± 13.5°, p = 0.000) than the inexperienced participants. Discussion: The results of this study indicate several significant kinematic differences between the experienced and inexperienced SUP participants. These variations in technique were noted in the shoulder, elbow and hip and are evident in other aquatic paddling sports where injury rates are higher in these joints. These finding may be valuable for coaches, therapists and participants needing to maximize performance and minimize injury risk during participation in SUP.Full Tex

    Time relations and structural-stratigraphic patterns in ophiolite accretion, west central Klamath Mountains, California

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    New geochronological data and published structural and stratigraphic data show that two distinctly different ophiolitic assemblages formed in general proximity to one another at nearly the same time and were subsequently imbricated along a regional thrust zone. The Josephine ophiolite constitutes a complete oceanic crust and upper mantle sequence which lies within the western Jurassic belt of the Klamath province. Within the study area the Josephine ophiolite was formed by seafloor spreading at about 157 m.y. before present. It was immediately covered by a thin pelagic and hemipelagic sequence which grades into a thick flysch sequence, both of which comprise the Galice Formation. The Galice flysch was derived from volcanic arc and uplifted continental margin orogenic assemblages. A major nonvolcanic source for the Galice flysch appears to have been the western Paleozoic and Triassic belt of the Klamath province exposed to the east. Proximal volcanic arc activity migrated to the site of the Josephine-Galice section by 151 m.y. and is represented by numerous dikes and sills which intrude the ophiolite and Galice Formation. The Preston Peak ophiolite is a polygenetic assemblage consisting of (1) a pre-mid-Jurassic tectonitic peridotite-amphibolite substrate which represents disrupted and unroofed basement of the western Paleozoic and Triassic belt and (2) an upper mafic complex which was intruded through and constructed above the tectonite substrate at about 160 m.y. The mafic complex consists primarily of diabase hypabyssal rocks that are overlain by diabase-clast breccia and hemipelagic deposits. A major arc-plutonic complex was emplaced into the Preston Peak ophiolite in at least two pulses at 153 and 149 m.y. Major phases of this complex consist of wehrlite, gabbro, pyroxene diorite, and hornblende diorite. The Josephine ophiolite is interpreted as the remnants of interarc basin crust. The Preston Peak ophiolite is interpreted as either a primitive remnant arc complex or a rift edge facies for the Josephine interarc basin. The Galice Formation represents a submarine fan complex that was built on juvenile crust of the Josephine basin floor. During the time interval of 153 to 149 m.y. the locus or arc magmatism migrated to an area which included the interarc basin floor and the remnant arc or basin edge. The basin shortly thereafter closed by convergent tectonics during the Nevadan orogeny resulting in the imbrication of the Josephine and Preston Peak ophiolites and their superimposed arc assemblages. The transition from seafloor spreading generation of Josephine ophiolite to its tectonic accretion by convergence and basin closure occurred within 5 to 10 m.y. The process of rifting and ophiolite formation in series with convergence and ophiolite accretion is considered an important mechanism for generating and displacing allocthonous terranes in the Klamath Mountains-Sierra Nevada region, and perhaps throughout the western cordillera

    Toward respiratory assessment using depth measurements from a time-of-flight sensor

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    Introduction: There is increasing interest in technologies that may enable remote monitoring of respiratory disease. Traditional methods for assessing respiratory function such as spirometry can be expensive and require specialist training to perform and interpret. Remote, non-contact tracking of chest wall movement has been explored in the past using structured light, accelerometers and impedance pneumography, but these have often been costly and clinical utility remains to be defined. We present data from a 3-Dimensional time-of-flight camera (found in gaming consoles) used to estimate chest volume during routine spirometry maneuvres. Methods: Patients were recruited from a general respiratory physiology laboratory. Spirometry was performed according to international standards using an unmodified spirometer. A Microsoft Kinect V2 time-of-flight depth sensor was used to reconstruct 3-dimensional models of the subject's thorax to estimate volume-time and flow-time curves following the introduction of a scaling factor to transform measurements to volume estimates. The Bland-Altman method was used to assess agreement of model estimation with simultaneous recordings from the spirometer. Patient characteristics were used to assess predictors of error using regression analysis and to further explore the scaling factors. Results: The chest volume change estimated by the Kinect camera during spirometry tracked respiratory rate accurately and estimated forced vital capacity (FVC) and vital capacity to within ± <1%. Forced expiratory volume estimation did not demonstrate acceptable limits of agreement, with 61.9% of readings showing >150 ml difference. Linear regression including age, gender, height, weight, and pack years of smoking explained 37.0% of the variance in the scaling factor for volume estimation. This technique had a positive predictive value of 0.833 to detect obstructive spirometry. Conclusion: These data illustrate the potential of 3D time-of-flight cameras to remotely monitor respiratory rate. This is not a replacement for conventional spirometry and needs further refinement. Further algorithms are being developed to allow its independence from spirometry. Benefits include simplicity of set-up, no specialist training, and cost. This technique warrants further refinement and validation in larger cohorts

    Traditional, Online, and Flipped: A Preliminary Analysis of Instructional Approaches on Student Performance in a C# Programming Course

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    Although various approaches to course redesign have been proposed over the years “flipping” the classroom is quite popular across many disciplines, information systems notwithstanding. The purpose of this paper is to examine whether the instructional approach (i.e., traditional, online, and flipped) has an impact on student performance on specific course requirements in an undergraduate C# programming course. Data from several semesters were collected and analyzed using the Kruskal-Wallis H Test. Results indicated interesting but few statistically significant findings. A bright spot revealed that the median score for the flipped instructional approach for Course Average was within striking range of the online instructional approach and was approaching statistical significance in relation to the traditional instructional approach. This is encouraging given the time and effort put into the design of the flipped classroom. In sum, the study suggests that performance is approach-neutral. Future research will involve more students in the flipped classroom

    Remote, depth-based lung function assessment

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    Community College Students’ Perceptions of Law Enforcement

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    The purpose of this study was to extend our understanding of public perception towards law enforcement. Students from three different Kansas community colleges were surveyed about their perceptions of law enforcement effectiveness and professionalism, and what might impact those perceptions. A total of 159 community college students responded to the survey. The majority of the respondents were female (78%), and Caucasian (77.4%). Respondent’s age represented the following percentage breakdowns: 29.6% being 18-19 years old, 27.7% being 20-24 years old, and 30.8% being 25-34. Resulting in 88% of respondents being between the ages of 18-34 years old. Mean and standard deviation statistical procedures were calculated to determine the overall perception of law enforcement effectiveness (M = 3.60, SD = 0.800) and professionalism (M = 2.76, SD = 0.708). The categories of race and gender were further examined using mean and standard deviation procedures. The Analysis of Variance (ANOVA) procedure was used to analyze the data, with no significant differences in mean perceptions of law enforcement effectiveness by gender and race (F (1, 150) = 0.52, P=0.4712) or in mean perceptions of law enforcement professionalism (F (1, 149) = 2.40, P=0.1231). A Chi-Square test was used to determine there was no relationship difference between media consumption and gender (χ2 (3, N = 158) = 2.7478, p = 0.4322) or media consumption and race (χ2 (3, N = 155) = 2.5875, p = 0.4597). However, results did indicate a significant difference related to the total number of hours of media consumption and the perception of whether it was positive towards police (χ2 (15, N = 159) = 70.86, p \u3c .0001)
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