Nelson, Karen G.
Presents a lesson plan which introduces students in grades 7-9 to Willem de Kooning and the qualities that make his oil painting "Marilyn Monroe," an example of abstract expressionist style. Includes background information on the artist and the painting as well as instructional strategies, studio activities, and evaluation procedures.…
... Exhibition Determinations: ``De Kooning: A Retrospective'' SUMMARY: Notice is hereby given of the following... exhibition ``De Kooning: A Retrospective,'' imported from abroad for temporary exhibition within the...
...); Sheran Arden Yeates, 71 FR 39130, 39131 (2006); Dominick A. Ricci, 58 FR 51104, 51105 (1993); Bobby Watts... registration (when required), the Agency has revoked the practitioner's registration. James Stephen...
Detailed formulas are given in IEC 61508 for calculating Probability of Failure on Demand for 1oo1, 1oo2, 2oo2, 2oo3 and 1oo3 systems. Simplified PFD formulas are also derived for general k-out-of-n combinations, without incorporating all the elements utilized in IEC 61508 formulas. While there have been other studies on IEC 61508 formulas and the simplified k-out-of-n equations, none have proposed an inclusive generalized form of IEC 61508 formulas to replicate all the specific combinations covered by the standard. This paper uses a detailed analysis to derive a generalized PFD formula based on IEC 61508.6-2011 that can be applied to all k-out-of-n combinations. The proposed formula is verified against both IEC 61508 and the simplified formulas, and its application is demonstrated by a real life example.
Ujimoto, K. Victor
The universe of Japanese immigrants selected for this study consisted of a diverse group such as the kika nisei (returned second generation), the yobiyose (sponsored immigrant), and the gijutsu imin (technical immigrant). Each group possessed different characteristics. This present paper is limited in scope to the yobiyose and gijutsu imin because…
WINDS .FATfl SEPIC / ,K PERCENTAGE FREQUENCY OF WIND DIRECTION AND SPEED (FROM HOURLY OBSERVATIONS) , ~ ~ " , -N T A 411 -, :-7,J, 7.-7 , STATION I... dC .9 8’. S 6!_,.9 b.9 oj.9 8.9 7 00 75. 79. 3. 1.31 .9 81.9 81.0 P .2.1 e2.1 82.2 )j2.2 82.2 82.2 62.2 32.2 2 6000 75. 3’.. 38.7 1 8.5 ,2.5 i.5 12.7...8217§ 7 ’, c) 5’).9 DC .* 79 20000 4j__ 7 14 7__9__ ___ 65__ L,_ ___ D, 2. t~. S4. i5 L 5-* * 2’ S4 b 18000 4 . . . 3 (.1 3 . 4 4 £ 5 . 1 5 . 6 . 7 6
82 , 8 2.8 82s 82.8 .2,* 6. o 82.8 82.0 62_ ±a4 82 82 .F1 83 .a 83 a 443.4 81 ’ 3 l 8. 3 U 3I_ b4 .3 41ami 85. 85d 8! 1.7 P5 85,1...79 79,7 79. 7911 79*78oc 61W . Z 8 10I 8 1 .10 8 1 .... .. 7.1 82 . 81 . 9 8. 83 . 8563 86,0 86, 84a1 84, . 1.C; 84.3 68,9 779 ~ 4 ~ 84. 5,j 8, 8 6 AJ...62,40 82 . 7 83 .l1 8364 63, 83.1 83 * 81 83 63,91 83 %3. 83,9 6 8.33 6. 86 86,5 7l, 81 ,L 84d as es 9 7, 94
Telecommunications Terminal System Discussed [Takahiro Kawazoe; JIDOSHA GIJUTSU, Feb 88] 81 Development of Hand -Free Mobile Phone Reported [Nobuyuki Ishihara...34 concept announced by President Reagan a month after that made the eyes of the space transport scientific technicians of the world turn again to the...Aerospace Laboratory, the National Space Science Laboratory, and NASDA. The "Space Plane Coordinating Committee" was created by these three
Love, Jessica; McKoon, Gail; Gerrig, Richard J.
Current theories of text processing say little about how authors' narrative choices, including the introduction of small mysteries, can affect readers' narrative experiences. Gerrig, Love, and McKoon (2009) provided evidence that 1 type of small mystery--a character introduced without information linking him or her to the story--affects readers'…
If the diffusion model (Ratcliff & McKoon, 2008) is to account for the relative speeds of correct responses and errors, it is necessary that the components of processing identified by the model vary across the trials of a task. In standard applications, the rate at which information is accumulated by the diffusion process is assumed to be normally…
...-1222, firstname.lastname@example.org . New Hampshire (See Vermont) New Jersey Victoria Fekete, USDA Rural Development, 8000 Midlantic Drive, Suite 500N, Mt. Laurel, NJ 08054, (856) 787-7752, Victoria.Fekete@nj.usda... Street, Room 4311, Salt Lake City, UT 84138, (801) 524-4301, Roger.Koon@ut.usda.gov ....
Love, Jessica; McKoon, Gail
Research on shallow processing suggests that readers sometimes encode only a superficial representation of a text and fail to make use of all available information. Greene, McKoon, and Ratcliff (1992) extended this work to pronouns, finding evidence that readers sometimes fail to automatically identify referents even when these are unambiguous. In…
Cheung, K. C.; And Others
This collection of research papers considers extensions of the Rasch model. In Chapter 1, K. C. Cheung explains how measurement and testing in the classroom can be made more meaningful, particularly through the use of Rasch family item response models. In Chapter 2, K. W. Koon and K. C. Cheung apply the Rasch model in constructing a part-whole…
Koons discussed electric field and plasma wave measurements on satellite and rocket flights. Many of these studies were made with a Langmuir probe , and...is an effective probe for studying predissociative effects and identifying exit channels for Rydberg state deconposition. (4) the radiative lifetimes...being similar to the so-called air afterglow , although shifted towards longer wavelengths. With the implication that nitrogen and oxygen hitting the
Spacecraft charging at high altitudes: the SCATHA satellite program," in Spacecraft Charging by Magnetospheric Plasmas , A. Rosen Ed., Pro- gress in... magnetospheric plasma is very dense, it is usually "cold" and doesn’t cause significant charging . The equatorial ionosphere and the plasmasphere are such... Astronautics and Aeronautics, 47, p. 15, 1975. 3. Anderson, P. C., and H. C. Koons, " Spacecraft charging anomaly on a low-altitude
of Alabama Press, Tuscaloosa. 154 Ernenwein, E. G. and M . L . Hargrave. 2007. Archaeological Geophysics for DoD Field Use: a Guide for New and...G. Ernenwein, M . L . Hargrave, T. Sever, D. Harmon, F. Limp, B. Howell, M . Koons and J. Tullis. 2006. New Approaches to the Use and Integration of...American Antiquity 48:675-706. 156 Somers, L . E., M . L . Hargrave and contributions from Janet E. Simms. 2003. Geophysical Surveys in
Irving, J. B.
This case report describes the presentation and treatment of a case of aortic incompetence, resulting from a road traffic accident. The relevant literature is briefly reviewed. Aortic incompetence due to trauma has been described following non-penetrating chest injuries, such as kicks from horses (Barie, 1881), falls from heights and crushing accidents (Kissane, Koons and Clark, 1948; Levine, Roberts and Morrow, 1962). Despite the frequency of road traffic accidents, there have been no recent reports of traumatic aortic valve damage. PMID:4467876
AppI . Phys. 52, 2549 (1981). 3. S. G. Cornelison, D. J. Sellmyer and G. Hadjipanayis, J. Appl. Phys. 52, 1823 (1981). li * . 4. G. Hadjipanayis, M. Sc...23, 3349 (1981). 9. A. E. Clark, AppI . Phys. Lett. 23, 642 (1973). 10. H. T. Savage, A. E. Clark, S. J. Pickart, J. J. Rhyne and H. A. Alperin, IEEE...Trans. Magn. MAG-lO, 807 (1974). S 11. J.J. Croat, IEEE Trans. Magn. MAG-18, 1442 (1982). 12. N. C. Koon and B. N. Das, Appi . Phys. Lett. 39, 840 (1981
Spacecraft Charging by Magnetospheric Plasma , Progress in Aeronautics and Astronautics , Vol. 47, ed. A. Rosen, IAA, pp. 15-30 (1976). 3. H. C. Koons, P. F...AIAA 75-92 (January 20-22, 1975). 2. D. A. McPherson and W. R. Schober, " Spacecraft Charging at High Altitudes: The SCATHA Satellite Program," in...on the AF/NASI P78-2 (SCATHA) satellite were conducted with a plasma /ion source in the inner magnetosphere . These experiments were monitored with
Matsumoto, Keiichi; Endo, Keigo
Two kinds of Japanese guidelines for the data acquisition protocol of oncology fluoro-D-glucose-positron emission tomography (FDG-PET)/computed tomography (CT) scans were created by the joint task force of the Japanese Society of Nuclear Medicine Technology (JSNMT) and the Japanese Society of Nuclear Medicine (JSNM), and published in Kakuigaku-Gijutsu 27(5): 425-456, 2007 and 29(2): 195-235, 2009. These guidelines aim to standardize PET image quality among facilities and different PET/CT scanner models. The objective of this study was to develop a personal computer-based performance measurement and image quality processor for the two kinds of Japanese guidelines for oncology (18)F-FDG PET/CT scans. We call this software package the "PET quality control tool" (PETquact). Microsoft Corporation's Windows(™) is used as the operating system for PETquact, which requires 1070×720 image resolution and includes 12 different applications. The accuracy was examined for numerous applications of PETquact. For example, in the sensitivity application, the system sensitivity measurement results were equivalent when comparing two PET sinograms obtained from the PETquact and the report. PETquact is suited for analysis of the two kinds of Japanese guideline, and it shows excellent spec to performance measurements and image quality analysis. PETquact can be used at any facility if the software package is installed on a laptop computer.
Hare, Mary; Tanenhaus, Michael K.; McRae, Ken
Tworating studies demonstrate that English speakers willingly produce reduced relatives with internal cause verbs (e.g., Whisky fermented in oak barrels can have a woody taste), and judge their acceptability based on factors known to influence ambiguity resolution, rather than on the internal/external cause distinction. Regression analyses demonstrate that frequency of passive usage predicts reduced relative frequency in corpora, but internal/external cause status does not. The authors conclude that reduced relatives with internal cause verbs are rare because few of these verbs occur in the passive. This contrasts with the claim in McKoon and Ratcliff (McKoon, G., & Ratcliff, R. (2003). Meaning through syntax: Language comprehension and the reduced relative clause construction. Psychological Review, 110, 490–525) that reduced relatives like The horse raced past the barn fell are rare and, when they occur, incomprehensible, because the meaning of the reduced relative construction prohibits the use of a verb with an internal cause event template. PMID:22162904
Scales, Wayne; Ganguli, Gurudas; Crabtree, Chris; Rudakov, Leonid; Mithaiwala, Manish
Waves in the VLF range are of considerable interest in the magnetosphere since they are responsible for transporting energy and momentum and therefore impacting space weather. Ion ring beams can efficiently generate waves in the VLF frequency range between the electron and ion gyro-frequency (Mithaiwala et al., 2010). Generation of VLF waves by infinite extent ion ring beams have been extensively treated for a broad range of space plasma applications. However, ion ring distributions created by chemical release experiments in the ionosphere (Koons and Pongratz, 1981) and those that occur naturally during storms/substorms or solar-wind comet interactions are localized over a spatial extent. This presentation will consider a new computational model for the nonlinear evolution of VLF waves generated by a spatially localized ion ring beam. The model, though quite general, will have application to generation of VLF waves in the radiation belts by localized creation of an ion ring beam. The model includes the convective loss of energy through phenomenological electron-ion collisions, which models nonlinear scattering of electrostatic lower hybrid waves into large group velocity electromagnetic whistler/magnetosonic waves (Ganguli et al., 2010). Therefore the model, though electrostatic, includes critical electromagnetic effects in a computationally efficient fashion. An emphasis is placed on the determining the efficiency of extraction of VLF energy from the ion ring beam due to the spatial localization of the ion ring beam. It is shown that due to the convection of the VLF waves out of the source region, the efficiency of wave energy extraction is greatly enhanced. This is accompanied by a reduction in background and ion ring beam heating. The results will be used to highlight the importance of non-linear scattering to future active experiments in space. Mithaiwala et al. Phys. Plasma, doi.org/10.1063/1.3372842, 2010 Koons and Pongratz, JGR, 1981. Ganguli et al., Phys
Parker, Linda Neergaard; Minow, Joseph I.
It has been well established that POLAR orbiting satellites can see mild to severe charging levels during solar minimum conditions (Frooninckx and Sojka, 1992, Anderson and Koons, 1996, Anderson, 2012). However, spacecraft operations during solar maximum cannot be considered safe from auroral charging. Recently, we have seen examples of high level charging during the recent approach to solar maximum. We present here a survey of charging events seen by the Defense Meteorological Satellite Program (DMSP) satellites (F16, F17) during the solstices of 2011 and 2012. In this survey, we summarize the condition necessary for charging to occur in this environment, we describe how the lower than normal maximum conditions are conducive to the environment conditions necessary for charging in the POLAR orbit, and we show examples of the more extreme charging events, sometimes exceeding 1 kV, during this time period. We also show examples of other interesting phenomenological events seen in the DMSP data, but which are not considered surface charging events, and discuss the differences.
NeergaardParker, L.; Minow, Joseph I.
It has been well established that polar orbiting satellites can see mild to severe charging levels during solar minimum conditions (Frooninckx and Sojka, 1992, Anderson and Koons, 1996, Anderson, 2012). However, spacecraft operations during solar maximum cannot be considered safe from auroral charging. Recently, we have seen examples of high level charging during the recent approach to solar maximum. We present here a survey of charging events seen by the Defense Meteorological Satellite Program (DMSP) satellites (F16, F17) during the solstices of 2011 and 2012. In this survey, we summarize the condition necessary for charging to occur in this environment, we describe how the lower than normal maximum conditions are conducive to the environment conditions necessary for charging in the polar orbit, and we show examples of the more extreme charging events, sometimes exceeding 1 kV, during this time period. We also show examples of other interesting phenomenological events seen in the DMSP data, but which are not considered surface charging events, and discuss the differences.
Koon, Daniel; Hansen, Ole
We have calculated the sensitivity of van der Pauw resistances to local resistive variations for circular, square and astroid discs of infinitesimal thickness, as well as for the families of rounded crosses and cloverleafs, as a function of specimen parameters, using the direct formulas of our recent paper (Koon et al. 2013 J. Appl. Phys.114 163710) applied to ``reciprocally dual geometries'' (swapped Dirichlet and Neumann boundary conditions) described by Mareš et al.(2012 Meas. Sci. Technol. 23 045004). These results show that (a) the product of any such sensitivity function times differential area, and thus (b) the ratio of any two sensitivities, is invariant under conformal mapping, allowing for the pointwise determination of the conformal mapping function. The family of rounded crosses, which is bounded in parameter space by the square, the astroid and an ``infinitesimally thin'' cross, seems to represent the best geometry for focusing transport measurements on the center of the specimen while minimizing errors due to edge- or contact-effects. Made possible by an SLU Faculty research grant.
Thomas, C.; Goetz, J.; Klemm, J.; Weitz, R.
Film-badge doses are reconstructed for sixteen ships and the residence islands of Enewetak and Kwajalein Atolls resulting from the six nuclear detonations comprising Operation CASTLE (March-May 1954). Fallout from Shots BRAVO and ROMEO was the major source of contamination on most of the ships and islands. Varying amounts of fallout from Shots UNION, YANKEE, and NECTAR contributed somewhat to the total doses of the shipboard and island-based personnel; no fallout was experienced as a result of Shot KOON. Shipboard personnel received additional exposure from hulls and salt water piping systems that had become contaminated from operating in the radioactive waters of Bikini Lagoon. From the reconstructed radiation environments, both topside and below, an equivalent film badge dose is calculated and compared to actual dosimetry data. Agreement is very good during badged periods when the ships received significant fallout. When topside intensities were not documented, generally late in the operation when intensity levels were low, agreement is not as good. Calculated ship contamination doses of significance are in excellent agreement with limited available dosimetry data. Calculated average doses for shipboard personnel range from a low of 0.19 rem for the crew of the USS LST-825 to a high of 3.56 rem for the crew of the USS PHILIP. Average doses on the residence islands of Enewetak and Kwajalein Atolls are 1.09 rem and 0.32 rem, respectively.
Sun, Lei-Lei; Gu, Sheng-Hong; Wang, Xiao-Bin; Collier Cameron, Andrew; Cao, Dong-Tao; Wang, Yi-Bo; Xiang, Yue; Hui, Ho-Keung; Kwok, Chi-Tai; Yeung, Bill; Leung, Kam-Cheung
We report new photometric observations of the transiting exoplanetary system WASP-32 made by using CCD cameras at Yunnan Observatories and Ho Koon Nature Education cum Astronomical Centre, China from 2010 to 2012. Following our usual procedure, the observed data are corrected for systematic errors according to the coarse decorrelation and SYSREM algorithms so as to enhance the signal of the transit events. Combined with radial velocity data presented in the literature, our newly observed data and earlier photometric data in the literature are simultaneously analyzed to derive the physical parameters describing the system by employing the Markov chain Monte Carlo technique. The derived parameters are consistent with the result published in the original paper about WASP-32b, but the uncertainties of the new parameters are smaller than those in the original paper. Moreover, our modeling result supports a circular orbit for WASP-32b. Through the analysis of all available mid-transit times, we have refined the orbital period of WASP-32b; no evident transit timing variation is found in these transit events.
Gao, Tenghua; Itokawa, Nobuhide; Wang, Jian; Yu, Youxing; Harumoto, Takashi; Nakamura, Yoshio; Shi, Ji
We report on the investigation of perpendicular exchange bias in FePt (001 ) /NiO (1 ¯1 ¯1 ) orthogonal exchange couple with FePt partially L 10 ordered. From initial magnetization curve measurement and magnetic domain imaging, we find that, for the as-grown bilayer structure, the FePt layer experiences a small-angle magnetization rotation when it is magnetized near to saturation in film normal direction. After field cooling, the bilayer structure shows a significant enhancement of perpendicular magnetic anisotropy, indicating the field mediated coupling between the spins across the FePt/NiO interface. According to Koon's theoretical calculation on the basis of lowest energy ferromagnetic/antiferromagnetic coupling configuration for compensated spins at antiferromagnetic side, we consider slightly slanted Ni spins at the interface off the (1 ¯1 ¯1 ) easy plane can stabilize the spin coupling between FePt and NiO and result in the observed exchange bias in this paper. This consideration was further confirmed by stripe domain width calculation.
Flemetakis, Stamatis; Moulas, Evangelos; Kostopoulos, Dimitrios; Chatzitheodoridis, Elias
The Cycladic islands of Syros and Siphnos, Aegean Sea, Greece, represent subducted IAT and BABB remnants of the Neotethyan Pindos Ocean. Garnet porphyroblasts (Ø=1mm) in a glaucophane-zoisite eclogite from Kini locality on Syros are compositionally zoned and display a unique prograde heating path from a high-pressure greenschist-facies core with high XSps and low Mg# via a blueschist-facies mantle with moderate XSps and Mg# to an eclogite-facies rim with low XSps and high Mg#. The outermost 35 μm of the garnet rims show flat XSps with rapidly increasing outwards Mg#. Na-Act-Chl-Ph rimmed by Gln mark the greenschist-blueschist facies transition, whereas Pg rimmed by Omp and the incoming of Rt at the expense of Ttn signify the blueschist-eclogite facies transition. Raman barometry of quartz inclusions in the eclogitic garnet rims coupled with elastic modelling of the garnet host , and Zr-in-Rt and Grt-Cpx-Ph thermobarometry revealed near-UHP P-T conditions of the order of 2.6 GPa/660°C (maximum residual pressure was 0.8-0.9GPa). By contrast, the greenschist-blueschist transition lies at ~0.75 GPa/355°C. This pressure is in excellent agreement with the position of the albite = jadeite + quartz boundary calculated at 350°C using the observed omphacite composition corrected for jadeite activity (Koons & Thompson, 1985) . As a result, Cpx inclusions in garnet core signify the early entrance of garnet in the subduction zone history of the slab. Furthermore, the early growth of garnet (in lower pressures) observed in eclogites from Syros lies in great agreement with published slab-geotherms that indicate hot subduction and show a precocious garnet growth (Baxter and Caddick, 2013) . The complete absence of lawsonite and the great abundance of zoisite crystals, based on the stability fields of both minerals (Poli et al., 2009) , further constrain the P-T trajectory of the slab. Our new P-T estimates match published T distributions on the slab surface
Sun, Leilei; Gu, Shenghong; Wang, Xiaobin; Collier Cameron, Andrew; Cao, Dongtao; Wang, Yibo; Xiang, Yue; Hui, Ho-Keung; Kwok, Chi-Tai; Yeung, Bill; Ng, Eric; Grau Horta, Ferran
We report new photometric observations of the transiting exoplanetary system HAT-P-20, obtained using CCD cameras at Yunnan Observatories and Ho Koon Nature Education cum Astronomical Centre, China, from 2010 to 2013, and Observatori Ca l’Ou, Sant Marti Sesgueioles, Spain, from 2013 to 2015. The observed data are corrected for systematic errors according to the coarse de-correlation and SYSREM algorithms, so as to enhance the signal of the transit events. In order to consistently model the star spots and transits of this exoplanetary system, we develop a highly efficient tool STMT based on the analytic models of Mandel & Agol and Montalto et al. The physical parameters of HAT-P-20 are refined by homogeneously analyzing our new data, the radial velocity data, and the earlier photometric data in the literature with the Markov chain Monte Carlo technique. New radii and masses of both host star and planet are larger than those in the discovery paper due to the discrepancy of the radius among K-dwarfs between predicted values by standard stellar models and empirical calibration from observations. Through the analysis of all available mid-transit times calculated with the normal model and spotted model, we conclude that the periodic transit timing variations in these transit events revealed by employing the normal model are probably induced by spot crossing events. From the analysis of the distribution of occulted spots by HAT-P-20b, we constrain the misaligned architecture between the planetary orbit and the spin of the host star.
Xu, Ming; Wang, Yue; Xu, Shijie
The present paper addresses the existence of J 2 invariant relative orbits with arbitrary relative magnitude over the infinite time using the Routh reduction and Poincaré techniques in the J 2 Hamiltonian problem. The current research also proposes a novel numerical searching approach for J 2 invariant relative orbits from the dynamical system point of view. A new type of Poincaré mapping is defined from different central manifolds of the pseudo-circular orbits (parameterized by the Jacobi energy E, the polar component of momentum H z and the measure of distance Δ r between the fixed point and its central manifolds) to the nodal periods T d and the drifts of longitude of the ascending node during one period (ΔΩ), which differs from Koon et al.'s (AIAA 2001) definition on central manifolds parameterized by the same fixed point. The Poincaré mapping is surjective because it compresses the three-dimensional variables into two-dimensional images, and the mapping degenerates into a bijective mapping in consideration of the fixed points. An iteration algorithm to the degenerated bijective mapping is proposed from the continuation procedure to perform the ergodic representation of E- and H z -contour maps on the space of T d -ΔΩ. For the surjective mapping with Δ r ≠ 0, different pseudo-circular or elliptical orbits may share the same images. Hence, the inverse surjective mapping may achieve non-unique variables from a single image, which makes the generation of J 2 invariant relative orbits possible. The pseudo-circular or elliptical orbits generated from the surjective mapping will be defined in different meridian planes. Hence, the critical contribution of the present paper is the assignment of J 2 invariant relative orbits to different invariant parameters E and H z depending on the E- and H z -contour map, which will hold J 2 invariant relative orbits for extended durations. To investigate the high-order nonlinearity neglected by previous studies, a
Toy, V. G.; Reid Lindroos, Z.; Norris, R. J.; Cooper, A. F.
microstructural and textural variations. These variations are broadly a function of the volumetric proportion of amphibolite in the mylonite zone on the map scale. We propose that most of the difference in measured dip-slip rates and differential rock uplift along strike of the fault can be attributed to basic along-strike variation in shear strength resulting from variation in lithology. Other theories, such as that the Alpine Fault contains a lateral ramp near the Karangarua River (Little et al. 2005), or that a weaker crust beneath Otago allows the convergent component of plate boundary deformation to be distributed over a broader orogen (Upton et al. 2009) are not required, although they may operate in concert. Little, T.A, Cox, S., Vry, J.K., Batt, G.E., 2005. Variations in exhumation level and uplift rate along the oblique-slip Alpine fault, central Southern Alps, New Zealand. Geological Society of America Bulletin 117 (5), 707 Upton, P., Koons, P.O., Craw D., Henderson, C.M., Enlow, R. 2009. Along-strike differences in the Southern Alps of New Zealand: Consequences of inherited variation in rheology. Tectonics 28. 10.1029/2008TC002353
Gerbi, Christopher; Culshaw, Nicholas; Shulman, Deborah; Foley, Maura; Marsh, Jeffrey
Because km-scale shear zones play a first-order role in lithospheric kinematics, accurate conceptual and numerical models of orogenic development require predicting when and where they form. Although a strain-based algorithm in the upper crust for weakening due to faulting appears to succeed (e.g., Koons et al., 2010, doi:10.1029/2009TC002463), a comparable general rule for the viscous crust remains unestablished. Here we consider two aspects of the geological argument for a similar algorithm in the viscous regime, namely (1) whether predicting km-scale shear zone development based on a single parameter (such as strain or shear heating) is reasonable; and (2) whether lithologic variability inherent in most orogenic systems precludes a simple predictive rule. A review of tectonically significant shear zones worldwide and more detailed investigations in the Central Gneiss belt of the Ontario segment of the Grenville Province reveals that most km-scale shear zones occur at lithological boundaries and involve mass transfer, but have fairly little else in common. As examples, the relatively flat-lying Twelve Mile Bay shear zone in the western Central Gneiss belt bounds the Parry Sound domain and is likely the product of both localized anatexis and later retrograde hydration with attendant metamorphism. Moderately dipping shear zones in granitoids of the Grenville Front Tectonic Zone apparently resulted from cooperation among several complementary microstructural processes, such as grain size reduction, enhanced diffusion, and a small degree of metamorphic reaction. Localization into shear zones requires the operation of some spatially restricted processes such as stress concentration, metamorphism/fluid access, textural evolution, and thermal perturbation. All of these could be due in part to strain, but not necessarily linearly related to strain. Stress concentrations, such as those that form at rheological boundaries, may be sufficient to nucleate high strain
Spiegel, Edward A.
shown quite widely in colloquia and symposia. The films revealed phenomena of qualitative interest such as mergers, bridges, and tails, and the formation of bars. Similar results were also being obtained by Hohl around that time and both pieces of work were no doubt influential in shaping the thinking of people working in this field. One striking feature of the calculations was that spiral arms formed initially but were transient. To keep the spiral patterns from collapsing it seemed necessary to artificially heat the disks. Only later, when the existence of massive halos was recognized (by Ostriker and Peebles), could the true cause of stability be surmised. From the mid-seventies on, Kevin worked on topics in astrophysical fluid dynamics and applied mathematics, largely with students. Some of this work was published, but it has to be said that much of his best work was not. A good example of the latter is his three-part handwritten manuscript on the dynamics of barred spirals that he distributed to several people over thirty years ago. Many of his other unpublished calculations have been deposited in the Columbia Library, and there are no doubt several things of interest to be found among his papers. While one can only speculate on why so much of his work went unpublished, I find a remark by de Kooning quite helpful in thinking about it. In a review of book about the painter, Peter Schjeldahl reported that "He [de Kooning] made ...paintings...and destroyed nearly all of them, to his subsequent regret....He explained `I was so modest then that I was vain.'" When I accused Kevin of a similar mindset, he chuckled and said "You are right, but don't tell anyone." Kevin was widely read and he had a remarkable awareness ofliterature. He was especially devoted to the work of P.G. Wodehouse. He also loved the Marx Brothers and late in life discovered Zero Mostel of whom he became an instant fan. He was a sailor and a snorkler, and enjoyed trading quips with anyone who was
Bauman, William H., III
Lightning Launch Commit Criteria (LLCC) are designed to prevent space launch vehicles from flight through environments conducive to natural or triggered lightning and are used for all U.S. government and commercial launches at government and civilian ranges. They are maintained by a committee known as the NASA/USAF Lightning Advisory Panel (LAP). The previous LLCC for anvil cloud, meant to avoid triggered lightning, have been shown to be overly restrictive. Some of these rules have had such high safety margins that they prohibited flight under conditions that are now thought to be safe 90% of the time, leading to costly launch delays and scrubs. The LLCC for anvil clouds was upgraded in the summer of 2005 to incorporate results from the Airborne Field Mill (ABFM) experiment at the Eastern Range (ER). Numerous combinations of parameters were considered to develop the best correlation of operational weather observations to in-cloud electric fields capable of rocket triggered lightning in anvil clouds. The Volume Averaged Height Integrated Radar Reflectivity (VAHIRR) was the best metric found. Dr. Harry Koons of Aerospace Corporation conducted a risk analysis of the VAHIRR product. The results indicated that the LLCC based on the VAHIRR product would pose a negligible risk of flying through hazardous electric fields. Based on these findings, the Kennedy Space Center Weather Office is considering seeking funding for development of an automated VAHIRR algorithm for the new ER 45th Weather Squadron (45 WS) RadTec 431250 weather radar and Weather Surveillance Radar-1988 Doppler (WSR-88D) radars. Before developing an automated algorithm, the Applied Meteorology Unit (AMU) was tasked to determine the frequency with which VAHIRR would have allowed a launch to safely proceed during weather conditions otherwise deemed "red" by the Launch Weather Officer. To do this, the AMU manually calculated VAHIRR values based on candidate cases from past launches with known anvil cloud
Deseta, N.; Ashwal, L.; Andersen, T. B.
.8 to 14 wt %) but the gabbro is not (H2O content from 0 to 2.6 wt%). The hydrous nature of the PST is due to the preferential melting of hydrous minerals (chlorite and serpentine - peridotite, glaucophane, epidote, Mg-hornblende - gabbro) in the host rock, rather than later hydration associated with exhumation (greenschist facies metamorphism and later alteration). However, in the case of the gabbro, the melt can be hydrous, but is not always. Anhydrous, glassy PST is formed in association with hydrous PST in the gabbro host rock. The gabbroic PST nucleate at the boundary between a coarse-grained pegmatoidal gabbro and a fine-grained gabbro, whereas the exclusively hydrous peridotite-hosted PST only nucleate along pre-existing hydrated fractures. These facts are significant when considering the mechanism of formation of the pseudotachylyte; which is commonly thought to be associated with the preferential melting of hydrous minerals. An anhydrous melt in proximity to other hydrous melts formed contemporaneously must have formed by the same mechanism; one which can exploit more than just one rheological characteristic in the rock vis. hydrous mineralogy AND grain size changes. Furthermore the presence of anhydrous PST suggests that little or no fluid ingress occurred prior to or during PST generation. Hydrous crystallisation products in the gabbro such as glaucophane and edenite indicate that whole-sale melting of the wallrock amphiboles (glaucophane, edenite, actinolite) took place to produce a melt with dissolved H2O, out of which such blue amphiboles were able to crystallise. It is important to note that in order for amphiboles to crystallise out of a melt, H2O is required but necessarily to an under-saturated degree. i.e. it cannot be 'free' water occurring as a separate phase in the melt (Carmen and Gilbert, 1983 and Koons, 1982). It is unlikely therefore that the water in the gabbro-derived fusion melt was the result of solid-state dehydration of the wallrock