Field measurement of penetrator seismic coupling in sediments and volcanic rocks

Field experiments were conducted to determine experimentally how well a seismometer installed using a penetrator would be coupled to the ground. A dry lake bed and a lava bed were chosen as test sites to represent geological environments of two widely different material properties. At each site, two half-scale penetrators were fired into the ground, a three-component geophone assembly was mounted to the aft end of each penetrator, and dummy penetrators were fired at various distances to generate seismic signals. The recorded signals were digitized, and cross-spectral analyses were performed to compare the observed signals in terms of power spectral density ratio, coherence and phase difference. The analyses indicate that seismometers deployed by penetrators will be as well coupled to the ground as are seismometers installed by conventional methods for the frequency range of interest in earthquake seismology, although some minor differences were observed at frequencies near the upper limit of the frequency band

Lunar seismic data analysis

The scientific data transmitted continuously from all ALSEP (Apollo Lunar Surface Experiment Package) stations on the Moon and recorded on instrumentation tapes at receiving stations distributed around the Earth were processed. The processing produced sets of computer-compatible digital tapes, from which various other data sets convenient for analysis were generated. The seismograms were read, various types of seismic events were classified; the detected events were cataloged

The Individual and Collective Relationships of Levels of Aspiration. Expectation and Achievement to the Construct of Self Concept

A review of the literature revealed that while numerous studies exist relative to the self concept, no study was found that addressed itself specifically to the relationship and relative contribution to the self concept of aspirations, expectations and achievements. The ref ore. this study was launched addressing itself to the question, Are aspirations. expectations and achievements related to the construct of self concept? , to what extent are they related when considered as individual variables. in combinations or as a totality? The FitzGibbon Rating Scale (FRS) was used as the criterion variable. FRS scores were gathered by classroom teachers experienced with the FRS and upon whom interrator reliability data had been gathered. Data on aspirations. expectations. and achievements were gathered via a game especially designed for this study. Subjects (Ss) were 40 girls and 47 boys (N=87) enrolled in the Edith Bowen Teacher Education Laboratory School for the school year 1972-73 in grades 4, 5, and 6 at Utah State University. Results: Hypothesis 1a. the correlation between the FRS self concept scores a:.:d level of aspiration scores, was accepted in its null form. Hypothesis 1b. the correlation between the FRS self concept scores and level of expectation scores. was accepted in its null form. Hypothesis 1c, the correlation between the FRS self concept scores and level of achievement scores. was accepted in its null form. Hypothesis 2b, the correlation between the FRS self concept scores and the interrelationship scores between levels of aspiration, achievement and expectation, was accepted in its null form. Hypothesis 3. the correlation between the FRS self concept scores and the sum of the interrelationship scores among levels of aspiration, achievement and expectation, was accepted in its null form. Hypotheses 4 and 5 having to do with percent of successes and its relationship to the FRS were rejected. Hypotheses 2a, dealing with the aspiration-achievement interrelationship and its relationship to the FRS was rejected in its null form. It was the only variable studied that showed a positive significant relationship to the FRS self concept

The importance of strategic financial leadership in the UK public sector in a time of financial austerity

Given the severity of financial pressures on public authorities, this report is concerned with how finance managers in public services are coping with the demands placed on them and how they can demonstrate improved value by providing more effective strategic financial leadership. It considers how they are applying managerial approaches and solutions to the challenges of austerity and the role that the public sector finance function can play in this process

Authentic learning for pre-service teacherrs in a technology-rich environment

This paper shares the findings from a three year Participatory Action Research Study around the selection, implementation and effectiveness of educational technologies for enhancing learning in a Teacher Education subject for second year pre-service primary teachers. The innovative Project- Based subject is described using a critical lens. The paper will share how two lecturers and their students explored their changing roles as teachers and learners and the tensions that emerged between their beliefs about student centered, authentic learning and the role of technology. It will explore the ways the technological innovations began to reshape and inform thinking about teaching and learning practices

High power operation of an X-band gyrotwistron

We report the first experimental verification of a gyrotwistron amplifier. The device utilized a single 9.858 GHz, TE011 cavity, a heavily attenuated drift tube, and a long tapered output waveguide section. With a 440 kV, 200-245 A, 1 μs electron beam and a sharply tapered axial magnetic field, peak powers above 21 MW were achieved with a gain near 24 dB. Performance was limited by competition from a fundamental TE11 mode. A multimode code was developed to analyze this system, and simulations were in good agreement with the experiment

Tomography of atomic number and density of materials using dual-energy imaging and the Alvarez and Macovski attenuation model

Dual-energy computed tomography and the Alvarez and Macovski [Phys. Med. Biol. 21, 733 (1976)] transmitted intensity (AMTI) model were used in this study to estimate the maps of density (ρ) and atomic number (Z) of mineralogical samples. In this method, the attenuation coefficients are represented [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)] in the form of the two most important interactions of X-rays with atoms that is, photoelectric absorption (PE) and Compton scattering (CS). This enables material discrimination as PE and CS are, respectively, dependent on the atomic number (Z) and density (ρ) of materials [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)]. Dual-energy imaging is able to identify sample materials even if the materials have similar attenuation coefficients at single-energy spectrum. We use the full model rather than applying one of several applied simplified forms [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976); Siddiqui et al., SPE Annual Technical Conference and Exhibition (Society of Petroleum Engineers, 2004); Derzhi, U.S. patent application 13/527,660 (2012); Heismann et al., J. Appl. Phys. 94, 2073–2079 (2003); Park and Kim, J. Korean Phys. Soc. 59, 2709 (2011); Abudurexiti et al., Radiol. Phys. Technol. 3, 127–135 (2010); and Kaewkhao et al., J. Quant. Spectrosc. Radiat. Transfer 109, 1260–1265 (2008)]. This paper describes the tomographic reconstruction of ρ and Z maps of mineralogical samples using the AMTI model. The full model requires precise knowledge of the X-ray energy spectra and calibration of PE and CS constants and exponents of atomic number and energy that were estimated based on fits to simulations and calibration measurements. The estimated ρ and Z images of the samples used in this paper yield average relative errors of 2.62% and 1.19% and maximum relative errors of 2.64% and 7.85%, respectively. Furthermore, we demonstrate that the method accounts for the beam hardening effect in density (ρ) and atomic number (Z) reconstructions to a significant extent.S.J.L., G.R.M., and A.M.K. acknowledge funding through the DigiCore consortium and the support of a linkage grant (LP150101040) from the Australian Research Council and FEI Company

Analytical study of hydrogen turbopump cycles for advanced nuclear rockets Progress report, Sep. 15, 1964 - Sep. 15, 1965

Hydrogen turbopump cycles for obtaining high engine inlet pressures in advanced nuclear rockets, and data on gaseous nuclear reactors and heavy gas containmen

Results from the Apollo passive seismic experiment

Recent results from the Apollo Seismic Network suggest that primitive differentiation occurred in the outer shell of the moon to a depth of approximately 300 km and the central region of the moon is presently molten to a radius of between 200 and 300 km. If early melting to a depth of 300 to 400 km was a consequence of accretional energy, very short accretion times are required. It was shown that the best model for the zone of original differentiation is a crust 40 to 80 km thick, ranging in composition from anorthositic gabbro to gabbro, and overlying an ultramafic cumulate about 250 km thick. The best candidate for the molten core appears to be iron or iron sulphide. A new class of seismic signals recently were identified that may correspond to shallow moonquakes. These are rare, but much more energetic than the more numerous, deep moonquakes

Field Measurements of Penetrator Seismic Coupling in Sediments and Volcanic Rocks

Field experiments were conducted to determine how well a seismometer installed using a penetrator would be coupled to the ground. A dry-lake bed and a lava bed were chosen as test sites to represent geological environments of two widely different material properties. At each site, two half-scale penetrators were fired into the ground, a three-component geophone assembly was mounted to the aft end of each penetrator, and dummy penetrators were at various distances to generate seismic signals. These signals were detected by the penetrator-mounted geophone assembly and by a reference geophone assembly buried or anchored to surface rock and 1-m from the penetrator. The recorded signals were digitized, and cross-spectral analyses were performed to compare the observed signals in terms of power spectral density ratio, coherence, and phase difference. The analyses indicate that seismometers deployed by penetrators will be as well coupled to the ground as are seismometers installed by conventional methods for the frequency range of interest in earthquake seismology