WorldWideScience

Sample records for mach boot sequence

  1. Ski Boots

    Science.gov (United States)

    1995-01-01

    In cooperation with Raichle Molitor USA Inc. and the international Raichle organization, Comfort Products developed the Raichle Flexon concept in ski boots. The Flexon concept is an adaptation of the accordion-like corrugations of extravehicular space suit joints, which allows ski boots to flex without significant distortion. The design provides immediate transmission of power and therefore precision skiing. Comfort Products also applied heating element circuitry from Apollo astronaut's clothing to foot-warming devices in their boots in the 1970s.

  2. Frostbite in Ski Boots for Marines

    Science.gov (United States)

    2005-05-01

    Geh-simulator. Ski boot without gaiter, test 1: Water just above lasting margin Cycles New boot Used boot 3360 Dry water in the boot, test stopped...boot 2260 Dry feels wet 4375 Dry water in the boot, test stopped 8500 Humid 16600 water in the boot Water absorption 5.0% 8.5% Hiking shoe

  3. Running Boot Camp

    CERN Document Server

    Toporek, Chuck

    2008-01-01

    When Steve Jobs jumped on stage at Macworld San Francisco 2006 and announced the new Intel-based Macs, the question wasn't if, but when someone would figure out a hack to get Windows XP running on these new "Mactels." Enter Boot Camp, a new system utility that helps you partition and install Windows XP on your Intel Mac. Boot Camp does all the heavy lifting for you. You won't need to open the Terminal and hack on system files or wave a chicken bone over your iMac to get XP running. This free program makes it easy for anyone to turn their Mac into a dual-boot Windows/OS X machine. Running Bo

  4. BOOTES-3 STATUS

    Directory of Open Access Journals (Sweden)

    J. C. Tello

    2014-01-01

    Full Text Available BOOTES-3 es el primer observatorio rob ́otico ubicado en el h emisferio sur de la red BOOTES (Burst Observer and Optical Transient Exploring System. Fu ́e inaugurado e n febrero del 2009, y prontamente inici ́o sus op- eraciones. Est ́a ubicado cerca de Blenheim, Nueva Zelanda. Su objetivo cient ́ıfico principal es la observaci ́on y segui miento de las contrapartidas ́opticas de los GRB (Estal- lidos de Rayos Gamma, por sus siglas en ingl ́es, respondien do a las alertas de manera r ́apida y completamente aut ́onoma. Para esto est ́a equipado con una montura de alta v elocidad (6-10 segundos, y todo el observatorio est ́a controlado por el software RTS-2 (Remote Telescope Sy stem 2.

  5. Car boots: layers and drawers

    NARCIS (Netherlands)

    Van Kasteren, J.

    2003-01-01

    The car boot of practically any car appears to be pretty low on the list of items the manufacturer considers important.The world of glossy, state of the art and high-tech design seems to come to a halt behind the rear seat. Designers at Audi, the German car manufacturers, were well aware that this p

  6. Car boots: layers and drawers

    NARCIS (Netherlands)

    Van Kasteren, J.

    2003-01-01

    The car boot of practically any car appears to be pretty low on the list of items the manufacturer considers important.The world of glossy, state of the art and high-tech design seems to come to a halt behind the rear seat. Designers at Audi, the German car manufacturers, were well aware that this p

  7. Car boots: layers and drawers

    NARCIS (Netherlands)

    Van Kasteren, J.

    2003-01-01

    The car boot of practically any car appears to be pretty low on the list of items the manufacturer considers important.The world of glossy, state of the art and high-tech design seems to come to a halt behind the rear seat. Designers at Audi, the German car manufacturers, were well aware that this

  8. Accounting Boot Camp for College Juniors

    Science.gov (United States)

    Myring, Mark; Wrege, William; Van Alst, Lucinda

    2008-01-01

    We describe a day-long introduction to new accounting majors, which we call a boot camp. Boot camp it is an effort to make juniors more aware of their identity, career purposes and learning resources that are now parts of their world, much of which is not covered explicitly in the accounting curriculum. This paper provides an overview of the…

  9. Pneumatic boot for helicopter rotor deicing

    Science.gov (United States)

    Blaha, B. J.; Evanich, P. L.

    1981-01-01

    Pneumatic deicer boots for helicopter rotor blades were tested. The tests were conducted in the 6 by 9 ft icing research tunnel on a stationary section of a UH-IH helicopter main rotor blade. The boots were effective in removing ice and in reducing aerodynamic drag due to ice.

  10. Photometric Metallicities in Bootes I

    CERN Document Server

    Hughes, J; Dotter, A; Geisler, D

    2014-01-01

    We present new Stromgren and Washington data sets for the Bootes I dwarf galaxy, and combine them with the available SDSS photometry. The goal of this project is to refine a ground-based, practical, accurate method to determine age and metallicity for individual stars in Bootes I that can be selected in an unbiased imaging survey, without having to take spectra. We produce photometric metallicities from Stromgren and Washington photometry, for stellar systems with a range of $-1.0>[Fe/H]>-3.5$. To avoid the decrease in sensitivity of the Stromgren metallicity index on the lower red-giant branch, we replace the Stromgren v-filter with the broader Washington C-filter; we find that $CT_1by$ is the most successful filter combination, for individual stars with $[Fe/H]<-2.0$, to maintain ~0.2 dex $[Fe/H]$-resolution over the whole red-giant branch. We demonstrate that we can break the isochrones' age-metallicity degeneracy with these filters, using stars with log g=2.5-3.0, which have less than a 2% change in th...

  11. Phylogeny and new taxonomy of the Booted Eagles (Accipitriformes: Aquilinae).

    Science.gov (United States)

    Lerner, Heather; Christidis, Les; Gamauf, Anita; Griffiths, Carole; Haring, Elisabeth; Huddleston, Christopher J; Kabra, Sonia; Kocum, Annett; Krosby, Meade; Kvaløy, Kirsti; Mindell, David; Rasmussen, Pamela; Røv, Nils; Wadleigh, Rachel; Wink, Michael; Gjershaug, Jan Ove

    2017-01-09

    We present a phylogeny of all booted eagles (38 extant and one extinct species) based on analysis of published sequences from seven loci. We find molecular support for five major clades within the booted eagles: Nisaetus (10 species), Spizaetus (4 species), Clanga (3 species), Hieraaetus (6 species) and Aquila (11 species), requiring generic changes for 14 taxa. Additionally, we recommend that the Long-crested Eagle (Lophaetus occipitalis) and the Black Eagle (Ictinaetus malaiensis) remain in their monotypic genera, due to their distinctive morphology. We apply the recently resurrected genus Clanga for the spotted eagles (previously Aquila spp.) to resolve the paraphyly of the genus Aquila such that the clade including the Booted Eagle (H. pennatus), Little Eagle (H. morphnoides), Pygmy Eagle (H. weiskei), Ayres's Eagle (H. ayresii) and Wahlberg's Eagle (H. wahlbergi) can remain in the genus Hieraaetus. The Rufous-bellied Eagle should be retained in the genus Lophotriorchis. For consistency in English names, we recommend that the term "hawk-eagles" be used only for the species in the genera Nisaetus and Spizaetus. We suggest following new or modified English names: Cassin's Eagle (Aquila africana), Bonaparte's Eagle (A. spilogaster), Ayres's Eagle (Hieraaetus ayresii), and Black-and-chestnut Hawk-Eagle (Spizaetus isidori).

  12. Soccer players' fitting perception of different upper boot materials.

    Science.gov (United States)

    Olaso Melis, J C; Priego Quesada, J I; Lucas-Cuevas, A G; González García, J C; Puigcerver Palau, S

    2016-07-01

    The present study assessed the influence of upper boot materials on fitting perception. Twenty players tested three soccer boots only differing in the upper boot material (natural calf leather, natural kangaroo leather and synthetic leather). Players reported fitting perception and preference on specific foot areas using a perceived fitting scale. Ratings were averaged for every foot area. Repeated measures ANOVA was used to analyze the differences between boots. The kangaroo leather boots were perceived tighter and closer to the preferred fitting in general fitting, metatarsals area and instep area. The synthetic leather boots were perceived as the loosest and as the most distant boot from the preferred fitting in medial front area and instep area. In conclusion, the type of upper boot material influences the fitting perception of soccer players. The kangaroo leather was the material whose fitting was perceived closest to the players fitting preference.

  13. Recent Developments in the BOOTES Experiment

    Science.gov (United States)

    de Ugarte Postigo, A.; Mateo Sanguino, T. J.; Castro Cerón, J. M.; Páta, P.; Bernas, M.; Jelinek, M.; Hudec, R.; McBreen, S.; Berná, J. Á.; García Dabó, C. E.; Gorosabel, J.; Más-Hesse, J. M.; Soria, T.; de La Morena, B. A.; Torres Riera, J.; Castro-Tirado, A. J.

    2003-04-01

    BOOTES, the Burst Observer and Optical Transient Exploring System, is mostly a Spanish-Czech international collaboration that works to fill the space that there actually exists in the rapid variability Astronomy. It is specially aimed towards the detection and study of the optical transients that are generated in conjunction with the elusive GRBs (Gamma Ray Bursts). Since 1998 BOOTES has provided follow ups for more than 60 of these phenomena with the first of its observatories; the most important results obtained so far are the detection of an OT (Optical Transient) in the GRB 000313 error box and the non detection of optical emission simultaneous to the GRB 010220 event. With the recent inauguration of a second observatory BOOTES multiplies its science capabilities.

  14. CONTINUOUS MONITORING USING BOOTES WORLDWIDE NETWORK

    Directory of Open Access Journals (Sweden)

    David Hiriart

    2014-01-01

    Full Text Available Se presentan los avances en la instalaci ́on del quinto teles copio de la red mundial de telescopios rob ́oticos BOOTES. Este telescopio, denominado BOOTES–5, se instalar ́a en el Observatorio Astron ́omico Nacional en la sierra San Pedro M ́artir, en Baja California, M ́exico. La operaci ́on coordinada de este telescopio con los de la red BOOTES operando en China y Espa ̃na permitir ́a un monit oreo continuo de fuentes astron ́omicas.

  15. Marilyn Levine: "Brown Boots, Leather Laces."

    Science.gov (United States)

    Williams, Ray

    1988-01-01

    Presents a lesson plan which uses Marilyn Levine's "Brown Boots, Leather Laces" to introduce students in grades 10-12 to naturalistic representation and the "trompe l'oeil" artistic tradition. Discusses Levine's background. Includes instructional strategies and student objectives, as well as a photograph of the artwork. (GEA)

  16. Frostbite in ski boots for marines

    NARCIS (Netherlands)

    Heus, R.; Schols, E.; Kistemaker, L.

    2005-01-01

    Previous research have showed that cold injuries of feet occur more often than cold injuries of hands. Recently, an unexpectedly large number of cold injuries were observed during military training in Norway and a relationship between cold injuries and the use of the Alico ski boot was suspected. Th

  17. Conduct Disorders: Are Boot Camps Effective?

    Science.gov (United States)

    Jeter, LaVaughn V.

    2010-01-01

    Youth diagnosed with "conduct disorder" are often placed in programs using forced compliance and coercive control. One type of intervention used to treat conduct disorder is the boot camp. The basic idea is that disruptive behaviors can be corrected by strict behavioral regulation and an emphasis on skills training (Weis & Toolis 2009; Weis,…

  18. Conduct Disorders: Are Boot Camps Effective?

    Science.gov (United States)

    Jeter, LaVaughn V.

    2010-01-01

    Youth diagnosed with "conduct disorder" are often placed in programs using forced compliance and coercive control. One type of intervention used to treat conduct disorder is the boot camp. The basic idea is that disruptive behaviors can be corrected by strict behavioral regulation and an emphasis on skills training (Weis & Toolis 2009; Weis,…

  19. Frostbite in ski boots for marines

    NARCIS (Netherlands)

    Heus, R.; Schols, E.; Kistemaker, L.

    2005-01-01

    Previous research have showed that cold injuries of feet occur more often than cold injuries of hands. Recently, an unexpectedly large number of cold injuries were observed during military training in Norway and a relationship between cold injuries and the use of the Alico ski boot was suspected.

  20. AN INNOVATIVE SKI-BOOT: DESIGN, NUMERICAL SIMULATIONS AND TESTING

    Directory of Open Access Journals (Sweden)

    Stefano Corazza

    2005-09-01

    Full Text Available The present work is concerned with the design of an innovative ski-boot. In order to optimize ergonomics and biomechanical behavior of the ski-boot it is important to take into account the orientation of the leg with respect to the ground. The SGS system (Stance Geometry System developed in this work allows the skier to adjust for posture in the frontal plane by rotating the sole of the boot about the antero-posterior axis (ski-boot is then locked in the desired position before skiing. A simplified model of the effect of ski-boot deformation on skiing behavior is used to evaluate the minimal stiffness the system must have. An experimental analysis on the ski slopes was carried out to provide ski-boot deformations and loading data in different skiing conditions, to be used in numerical simulations. Finite Elements Method (FEM simulations were performed for optimal design of the joint between ski-boot and sole. The active loads and local ski-boot deformations during small- and large-radius turns were experimentally determined and used to validate a FEM model of the ski-boot. The model was used to optimize the design for maximum stiffness and to demonstrate the efficacy of virtual design supported by proper experimental data. Mean loads up to 164% body weight were measured on the outer ski during turning. The new SGS design system allows the adjustment of lateral stance before using the ski-boot, optimizing the ski-boot stiffness through FEM analysis. Innovative aspects of this work included not only the stance geometry system ski-boot but also the setup of a virtual design environment that was validated by experimental evidence. An entire dataset describing loads during skiing has been obtained. The optimized SGS ski-boot increases intrinsic knee stability due to proper adjustment of lateral stance, guaranteeing appropriate stiffness of the ski-boot system

  1. The Age and Metallicity of the Bootes I System

    CERN Document Server

    Hughes, Joanne; Bossi, Anne

    2008-01-01

    We present Washington photometry of a field central to the Bootes I dwarf spheroidal galaxy, which was discovered as a stellar overdensity in the Sloan Digital Sky Survey (DR5). We show that the Washington filters are much more effective than the Sloan filters in separating the metal-poor turn-off stars in the dwarf galaxy from the foreground stars. We detect 165 objects in the field, and statistically determine that just over 40% of the objects are non-members. Our statistical analysis mostly agrees with radial velocity measurements of the brighter stars. We find that that there is a distinct main-sequence turn-off and subgiant branch, where there is some evidence of a spread in chemical abundance. Any evidence of an age spread is limited to a few billion years. The brightest 7 Bootes I members give a (photometric-color derived) weighted mean iron-abundance of [Fe/H]=-2.1+/-0.4, and the best-fit isochrone is the 14.1 Gyr, Z=0.0002 model, with DM=19.11 and E(B-V)=0.02.

  2. An Innovative Ski-Boot: Design, Numerical Simulations and Testing

    OpenAIRE

    Stefano Corazza; Claudio Cobelli

    2005-01-01

    The present work is concerned with the design of an innovative ski-boot. In order to optimize ergonomics and biomechanical behavior of the ski-boot it is important to take into account the orientation of the leg with respect to the ground. The SGS system (Stance Geometry System) developed in this work allows the skier to adjust for posture in the frontal plane by rotating the sole of the boot about the antero-posterior axis (ski-boot is then locked in the desired position before skiing). A si...

  3. Students Become Scientists at Science Skills Boot Camp | Poster

    Science.gov (United States)

    At the 2016 Science Skills Boot Camp (SSBC), a one-day training program designed for NIH summer interns with little or no prior research experience, students gathered to learn about basic research and laboratory skills. The boot camp provided a unique opportunity for interns to expand their knowledge of simple bench techniques, scientific papers, and ways to communicate their research.

  4. Effect of flow material ski boots on foot circulation.

    Science.gov (United States)

    Höflin, F; Kempi, V; van der Linden, W; Ringquist, I

    1976-01-01

    The effect of modern "flow material" ski boots on foot circulation was studied. Pressure inside a flow material ski boot was found to be markedly higher than in a conventional ski boot. In some places the pressure exceeded the diastolic pressure in the foot. 113mIndium chloride, which when injected intravenously is bound to transferrin was used for blood pool scanning. In healthy young volunteers the uptake of radioactivity in the two feet--one with and one without a ski boot--was compared. The activity level of the foot with the ski boot was significantly lower than in the other foot. After corrections were made for absorption by the boot, a significant difference remained. Plethysmographic studies were performed with a mercury strain gauge using a ski boot in which a hole was cut over the big toe. No difference was demonstrated between the blood pressure at the leg just above the boot top and at the big toe. The arterial pulse wave at the big toe was altered; i.e., there was an absence of a dichrotic wave. Intramuscular perfusion was studied with 133xenon. The disappearance curve in a foot with a boot was more shallow than that in a bare foot. Unbuckling resulted in an immediate fall in radioactivity, the disappearance curve then becoming identical to that of the bare foot. The results indicate that when flow material ski boots are to be used by skiers who are not in the habit of unbuckling for short intervals, buckle tension should not be too high.

  5. Core Concepts: Orthopedic Intern Curriculum Boot Camp.

    Science.gov (United States)

    Seeley, Mark A; Kazarian, Erick; King, Brandon; Biermann, Janet S; Carpenter, James E; Caird, Michelle S; Irwin, Todd A

    2016-01-01

    Orthopedic surgical interns must gain a broad array of clinical skills in a short time. However, recent changes in health care have limited resident-patient exposures. With the reported success of simulation training in the surgical literature, the American Board of Orthopaedic Surgery (ABOS) and Residency Review Committee for Orthopaedic Surgery have required that surgical simulation training be a component of the intern curricula in orthopedic surgical residencies. This study examined the short-term effectiveness of an orthopedic "intern boot camp" covering 7 of 17 simulation training concept modules published by the ABOS. Eight orthopedic post-graduate year 1 (PGY-1) residents (study group) completed a structured 3-month curriculum and were compared with 7 post-graduate year 2 (PGY-2) residents (comparison group) who had just completed their orthopedic surgical internship. Seven core skills were assessed using both task-specific and global rating scales. The PGY-1 residents demonstrated a statistically significant improvement in all 7 modules with respect to their task-specific pre-test scores: sterile technique (P=.001), wound closure (P<.001), knot tying (P=.017), casting and splinting (P<.001), arthrocentesis (P=.01), basics of internal fixation (P<.001), and compartment syndrome evaluation (P=.004). After the camp, PGY-1 and -2 scores in task-specific measures were not significantly different. A 3-month simulation-based boot camp instituted early in orthopedic internship elevated a variety of clinical skills to levels exhibited by PGY-2 residents.

  6. Boot Loader para Microcontroladores PIC serie 18

    Directory of Open Access Journals (Sweden)

    Francisco Javier Villalobos Piña

    2006-01-01

    Full Text Available El presente trabajo expone el diseño de un boot loader, programa que permanece residente en un microcontrolador PIC18F452. Dicho programa permite grabar cualquier aplicación en el PIC sin el uso de un programador. Esta ventaja, no solo facilita el diseño de aplicaciones de control digital mediante la familia 18 de Microchip, sino que evita que el procesador se monte y desmonte continuamente, debido a lo cual, disminuyen los daños que por mal manejo pudiera sufrir el procesador. Se reporta igualmente el programa en visual Delphi, que permite leer, grabar y ejecutar los archivos hexadecimales del procesador, y probar la integridad del dispositivo

  7. [Measuring pressure distribution on the human tibia in ski boots].

    Science.gov (United States)

    Schaff, P; Hauser, W

    1987-09-01

    Pressure distribution inside shoes is of great importance for orthopaedic and biomechanical inquiries. Especially in sports, safety and comfort depend essentially on this quantity, which also determines whether a shoe is well suited for a certain discipline. Therefore, the measurement of pressure distribution allows detailed and objective statements about these factors. Using a set of newly developed thin and highly flexible measuring mats and the corresponding electronic equipment, such statements have become possible. First results with this method were obtained in alpine skiing. 8 different types of ski boots (sizes 5 and 8) worn by 14 subjects were tested on different foreward leans and temperatures using 7-point measuring mats (2 cm2/point) fixed between the boot shaft and the front of the lower leg of each leg. Additional measurements on three different types of boots using a 3 x 24-point mat (1 cm2/point) for the lower leg, as well as measurements underneath the foot with a 14-point (2 cm2/point) and a 80-point (1 cm2/point) mat were performed. A complementary determination of the force at the heel element of a ski binding and a registration of muscular activity (EMG) helped in the interpretation of the results. Some field research using telemetry completed our study. Considerable variations between different boots were found in value and location of pressure maxima. Traditional boots show high pressure values over the instep at foreward leans of 35 degrees and a rise of pressure underneath the forefoot while fixing the buckles, whereas minimal pressure over the instep, no compression of the forefoot and a pressure maximum near the upper end of the shaft are observed in rear entry boots. The force at the heel-important for binding release-varies widely between different boots at the same foreward lean. There was no asymmetry between the pressure distributions of right and left. The pressure distributions for different subjects measured in the same boot were

  8. Emergency Medicine Residency Boot Camp Curriculum: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Ataya, Ramsey

    2015-03-01

    Full Text Available Introduction: Establishing a boot camp curriculum is pertinent for emergency medicine (EM residents in order to develop proficiency in a large scope of procedures and leadership skills.  In this article, we describe our program’s EM boot camp curriculum as well as measure the confidence levels of resident physicians through a pre- and post-boot camp survey. Methods: We designed a one-month boot camp curriculum with the intention of improving the confidence, procedural performance, leadership, communication and resource management of EM interns. Our curriculum consisted of 12 hours of initial training and culminated in a two-day boot camp. The initial day consisted of clinical skill training and the second day included code drill scenarios followed by interprofessional debriefing.   Results: Twelve EM interns entered residency with an overall confidence score of 3.2 (1-5 scale across all surveyed skills. Interns reported the highest pre-survey confidence scores in suturing (4.3 and genitourinary exams (3.9. The lowest pre-survey confidence score was in thoracostomy (2.4. Following the capstone experience, overall confidence scores increased to 4.0. Confidence increased the most in defibrillation and thoracostomy. Additionally, all interns reported post-survey confidence scores of at least 3.0 in all skills, representing an internal anchor of “moderately confident/need guidance at times to perform procedure.” Conclusion: At the completion of the boot camp curriculum, EM interns had improvement in self-reported confidence across all surveyed skills and procedures. The described EM boot camp curriculum was effective, feasible and provided a foundation to our trainees during their first month of residency. [West J Emerg Med. 2015;16(2:356–361.

  9. Evaluating the Effectiveness of the General Surgery Intern Boot Camp.

    Science.gov (United States)

    Schoolfield, Clint S; Samra, Navdeep; Kim, Roger H; Shi, Runhua; Zhang, Wayne W; Tan, Tze-Woei

    2016-03-01

    The aim of our study is to evaluate the effectiveness of newly implemented general surgery intern boot camp. A 2-day didactic and skills-based intern boot camp was implemented before the start of clinical duties. Participants who did not attend all boot camp activities and had prior postgraduate training were excluded. A survey utilizing a 5-point Likert scale scoring system was used to assess the participants' confidence to perform intern-level tasks before and after the boot camp. Subgroup analyses were performed comparing changes in confidence among graduates from home institution versus others and general surgery versus other subspecialties. In the analysis, 21 participants over two years were included. Among them, 7 were graduates from home institution (4 general surgery, 3 subspecialty) and 14 were from other institutions (6 general surgery and 8 subspecialty). There were significant increases in overall confidence levels (pre = 2.79 vs post = 3.43, P surgery (2.78 vs 3.46, P = 0.001) and other specialties (2.74 vs 3.34, P surgery intern boot camp before the start of official rotation is effective in improving confidence level in performing level-appropriate tasks of the incoming new interns.

  10. Advances in Pediatric Cardiology Boot Camp: Boot Camp Training Promotes Fellowship Readiness and Enables Retention of Knowledge.

    Science.gov (United States)

    Ceresnak, Scott R; Axelrod, David M; Sacks, Loren D; Motonaga, Kara S; Johnson, Emily R; Krawczeski, Catherine D

    2017-03-01

    We previously demonstrated that a pediatric cardiology boot camp can improve knowledge acquisition and decrease anxiety for trainees. We sought to determine if boot camp participants entered fellowship with a knowledge advantage over fellows who did not attend and if there was moderate-term retention of that knowledge. A 2-day training program was provided for incoming pediatric cardiology fellows from eight fellowship programs in April 2016. Hands-on, immersive experiences and simulations were provided in all major areas of pediatric cardiology. Knowledge-based examinations were completed by each participant prior to boot camp (PRE), immediately post-training (POST), and prior to the start of fellowship in June 2016 (F/U). A control group of fellows who did not attend boot camp also completed an examination prior to fellowship (CTRL). Comparisons of scores were made for individual participants and between participants and controls. A total of 16 participants and 16 control subjects were included. Baseline exam scores were similar between participants and controls (PRE 47 ± 11% vs. CTRL 52 ± 10%; p = 0.22). Participants' knowledge improved with boot camp training (PRE 47 ± 11% vs. POST 70 ± 8%; p cardiology knowledge after the training program and had excellent moderate-term retention of that knowledge. Participants began fellowship with a larger fund of knowledge than those fellows who did not attend.

  11. 14 CFR 23.1416 - Pneumatic de-icer boot system.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Pneumatic de-icer boot system. 23.1416... Safety Equipment § 23.1416 Pneumatic de-icer boot system. If certification with ice protection provisions is desired and a pneumatic de-icer boot system is installed— (a) The system must meet the...

  12. Economic Analysis for Commingling Effects of Insect Activity in the Elevator Boot Area.

    Science.gov (United States)

    Tilley, Dennis R; Casada, Mark E; Langemeier, Michael R; Subramanyam, Bhadriraju; Arthur, Frank H

    2015-12-01

    Boot areas in commercial grain elevators and feed mills contribute to commingling of insects with grain that moves through the elevator leg. A partial budget and stochastic dominance model were developed to improve pest management decision-making and risk analysis assessment from commingling effects of insect activity in the boot area. Modified pilot-scale bucket elevator legs, containing residual wheat or corn, were infested with varying insect pest densities prior to clean grain transfers. Appropriate grain discounts were applied to grain samples obtained from clean grain transfers over either: 1) insect-free and untreated boots, 2) infested and untreated boots, or 3) infested and chemical-treated (β-cyfluthrin) boots. The insect-free boots simulated performing clean-out of the boot area. Partial budget analysis and stochastic dominance modeling indicated that boot sanitation (cleanout) about every 30 d, avoiding costly grain discounts from insect commingling, is the preferred choice. Although chemical spray treatments of the empty boot may reduce insect populations of some boot residual grains, boot cleanout always had lower and usually zero insect pest populations in the boot residual grain, providing higher facility operational net income without the use of chemicals.

  13. Science Skills Boot Camp Gets Interns Ready for Research | Poster

    Science.gov (United States)

    By Ashley DeVine, Staff Writer Summer interns learned how to read a scientific paper, present a poster, maintain a laboratory notebook, and much more, at the Science Skills Boot Camp in June. “It was a great experience, and it was a great opportunity to meet some of the other interns also working on the campus,” said Alyssa Klein, a Werner H. Kirsten student intern in the Cellular Immunology Group, Laboratory of Molecular Immunoregulation. “The boot camp covered many topics essential to being a good scientist and science researcher.”

  14. The Burst Observer and Optical Transient Exploring System (BOOTES)

    Science.gov (United States)

    Castro-Tirado, A. J.; Soldán, J.; Bernas, M.; Páta, P.; Rezek, T.; Hudec, R.; Mateo Sanguino, T. J.; de La Morena, B.; Berná, J. A.; Rodríguez, J.; Peña, A.; Gorosabel, J.; Más-Hesse, J. M.; Giménez, A.

    1999-09-01

    The Burst Observer and Optical Transient Exploring System (BOOTES) is considered as a part of the preparations for the ESA's satellite INTEGRAL, and is currently being developed in Spain, in collaboration with two Czech institutions. It makes use of two sets of wide-field cameras 240 kms apart, and two robotic 0.3-m telescopes. The first observing station (BOOTES-1) is located in Huelva (Spain) and the first light was obtained in July 1998. During the test phase, it has provided rapid follow-up observations for 5 GRBs detected by the BATSE aboard the CGRO. The system will fully operate in late 1999.

  15. Effect of work boot type on work footwear habits, lower limb pain and perceptions of work boot fit and comfort in underground coal miners.

    Science.gov (United States)

    Dobson, Jessica A; Riddiford-Harland, Diane L; Bell, Alison F; Steele, Julie R

    2017-04-01

    Lower limb injuries are highly prevalent in underground coal mining. Wearing gumboots with inadequate ankle support was thought to contribute to these injuries. Despite the uptake of leather lace-up boots, which provide more ankle support, no recent research could be found investigating the effect of this alternative work boot in underground coal mining. Consequently, this study aimed to determine whether boot type (gumboot, leather lace-up boot) influenced work footwear habits, foot problems, lower limb pain, lower back pain, or perceptions of work boot fit and comfort in underground coal miners. Chi-squared tests were applied to 358 surveys completed by underground coal miners to determine whether responses differed significantly (p underground coal mining work boot that is comfortable and reduces the high incidence of foot problems and lower limb pain suffered by underground coal miners. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Evaluation of a pneumatic boot deicing system on a general aviation wing model

    Science.gov (United States)

    Albright, A. E.; Kohlman, D. L.; Schweikhard, W. G.; Evanich, P.

    1981-01-01

    The aerodynamic characteristics of a typical modern general aviation airfoil were investigated with and without a pneumatic boot ice protection system. The ice protection effectiveness of the boot was studied. This includes the change in drag on the airfoil with the boot inflated and deflated, the change in drag due to primary and residual ice formation, drag change due to cumulative residual ice formation, and parameters affecting boot effectiveness. Boot performance was not affected by tunnel total temperature or velocity. Marginal effect in performance was associated with angle of attack. Significant effects on performance were caused by variations in droplet size, LWC, ice cap thickness inflation pressure, and surface treatment.

  17. Academic Boot Camp for the Writing of Psychology Research Reports

    Science.gov (United States)

    Skues, Jason L.; Wise, Lisa

    2014-01-01

    Herein, we describe the implementation of, and responses to, a structured writing workshop in the form of an academic boot camp. Participants were 42 undergraduate psychology students from a medium-sized Australian university who were completing their major assignment for the semester. A majority of the students expressed satisfaction with the…

  18. Academic Boot Camp for the Writing of Psychology Research Reports

    Science.gov (United States)

    Skues, Jason L.; Wise, Lisa

    2014-01-01

    Herein, we describe the implementation of, and responses to, a structured writing workshop in the form of an academic boot camp. Participants were 42 undergraduate psychology students from a medium-sized Australian university who were completing their major assignment for the semester. A majority of the students expressed satisfaction with the…

  19. Outburst from SS 433 observed with BOOTES-2/COLORES

    Science.gov (United States)

    Caballero-Garcia, M. D.; Castro-Tirado, A.; Jelinek, M.; et al.

    2014-08-01

    In light of the recent extreme outburst of SS 433 (ATELs #6347, #6355) and follow-up by SWIFT (ATEL #6364) the 0.6m TELMA robotic telescope at the BOOTES-2 (+COLORES) astronomical station in Malaga (Spain), obtained optical 4000-9000 A spectra starting at 2014-08-01 and ending at 2014-08-07.

  20. Planning and Executing the Neurosurgery Boot Camp: The Bolivia Experience.

    Science.gov (United States)

    Ament, Jared D; Kim, Timothy; Gold-Markel, Judah; Germano, Isabelle M; Dempsey, Robert; Weaver, John P; DiPatri, Arthur J; Andrews, Russell J; Sanchez, Mary; Hinojosa, Juan; Moser, Richard P; Glick, Roberta

    2017-08-01

    The neurosurgical boot camp has been fully incorporated into U.S. postgraduate education. This is the first implementation of the neurosurgical boot in a developing country. To advance neurosurgical education, we developed a similar boot camp program, in collaboration with Bolivian neurosurgeons, to determine its feasibility and effectiveness in an international setting. In a collective effort, the Bolivian Society for Neurosurgery, Foundation for International Education in Neurological Surgery, Solidarity Bridge, and University of Massachusetts organized and executed the first South American neurosurgical boot camp in Bolivia in 2015. Both U.S. and Bolivian faculty led didactic lectures followed by a practicum day using mannequins and simulators. South American residents and faculty were surveyed after the course to determine levels of enthusiasm and their perceived improvement in fund of knowledge and course effectiveness. Twenty-four neurosurgery residents from 5 South American countries participated. Average survey scores ranged between 4.2 and 4.9 out of 5. Five Bolivian neurosurgeons completed the survey with average scores of 4.5-5. This event allowed for Bolivian leaders in the field to unify around education, resulting in the formation of an institute to continue similar initiatives. Total cost was estimated at $40 000 USD; however, significant faculty, industry, and donor support helped offset this amount. The first South American neurosurgical boot camp had significant value and was well received in Bolivia. This humanitarian model provides a sustainable solution to education needs and should be expanded to other regions as a means for standardizing the core competencies in neurosurgery. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Ernst Mach on the Self

    OpenAIRE

    Schrenk, Markus

    2011-01-01

    In his Contributions to the Analysis of the Sensations (Mach 1885) the phenomenalist philosopher Ernst Mach confronts us with a difficulty: “If we regard the Ego as a real unity, we become involved in the following dilemma: either we must set over against the Ego a world of unknowable entities […] or we must regard the whole world, the Egos of other people included, as comprised in our own Ego.” (Mach 1885: 21) In other words, if we start from a phenomenalist viewpoint, i.e., if we believ...

  2. Optical spectra of UX Ari with BOOTES-2

    Science.gov (United States)

    Caballero-Garcia, M. D.; Castro-Tirado, A.; Jelinek, M.

    2014-07-01

    Following the detection and subsequent monitoring of the new outburst from the RS CVn UX Ari by SWIFT and MAXI (ATEL#5907, #6315 , #6319 ), the 0.6m TELMA robotic telescope at the BOOTES-2 astronomical station Malaga (Spain), obtained optical 4000-9000 A spectra starting at 2014-07-19, 01:32:24.382 UT and ending at 04:25:55.652 UT.

  3. A Pediatric Cardiology Fellowship Boot Camp improves trainee confidence.

    Science.gov (United States)

    Allan, Catherine K; Tannous, Paul; DeWitt, Elizabeth; Farias, Michael; Mansfield, Laura; Ronai, Christina; Schidlow, David; Sanders, Stephen P; Lock, James E; Newburger, Jane W; Brown, David W

    2016-12-01

    Introduction New paediatric cardiology trainees are required to rapidly assimilate knowledge and gain clinical skills to which they have limited or no exposure during residency. The Pediatric Cardiology Fellowship Boot Camp (PCBC) at Boston Children's Hospital was designed to provide incoming fellows with an intensive exposure to congenital cardiac pathology and a broad overview of major areas of paediatric cardiology practice. The PCBC curriculum was designed by core faculty in cardiac pathology, echocardiography, electrophysiology, interventional cardiology, exercise physiology, and cardiac intensive care. Individual faculty contributed learning objectives, which were refined by fellowship directors and used to build a programme of didactics, hands-on/simulation-based activities, and self-guided learning opportunities. A total of 16 incoming fellows participated in the 4-week boot camp, with no concurrent clinical responsibilities, over 2 years. On the basis of pre- and post-PCBC surveys, 80% of trainees strongly agreed that they felt more prepared for clinical responsibilities, and a similar percentage felt that PCBC should be offered to future incoming fellows. Fellows showed significant increase in their confidence in all specific knowledge and skills related to the learning objectives. Fellows rated hands-on learning experiences and simulation-based exercises most highly. We describe a novel 4-week-long boot camp designed to expose incoming paediatric cardiology fellows to the broad spectrum of knowledge and skills required for the practice of paediatric cardiology. The experience increased trainee confidence and sense of preparedness to begin fellowship-related responsibilities. Given that highly interactive activities were rated most highly, boot camps in paediatric cardiology should strongly emphasise these elements.

  4. Rootkit Detection Using a Cross-View Clean Boot Method

    Science.gov (United States)

    2013-03-01

    bootmgr.exe while the boot sector loads. VBootkit disables full volume encryption and patches Multilingual User Interface (MUI) resources. eEye...SubVirt does [31]. Blue Pill installs by inserting a driver into the kernel that enables AMD - V’s Secure Virtual Machine (SVM). The driver then sets up...identify any malware that does not match a signature in the database. Another disadvantage is that an attacker could disable the security software before

  5. Boots on horses: limb protection or hyperflexion training aids in the showjumping horse.

    Science.gov (United States)

    Murphy, Jack

    2008-01-01

    Showjumping riders regularly employ various schooling strategies to control the horse's jump stride kinematics (JSK). Strategies include plyometric training regimes with fences of different heights and widths set at specific distances. Gymnastic grids teach the horse to jump cleanly. Rapping, once used almost routinely, is no longer in vogue. However, the use of performance enhancing (PE) boots on the distal hind limbs to alter equine JSK has become popular. There are two broad categories of PE boots: weighted and pressure. Some riders use so-called weighted boots on the horses' hind limbs during training and in competition to improve the jump stride. The application of so-called pressure boots may be little more than an adaptation of this technique. It appears that the PE boots induce hyperflexion of the hind limbs and incline the horse to jump fences cleanly. In the absence of scientific appraisal, it is unclear if such boots are acceptable and innovative training aids within equitation.

  6. An HI survey of the bootes void; 2, the analysis

    CERN Document Server

    Szomoru, A; Gregg, M D; Strauss, M A

    1995-01-01

    We discuss the results of a VLA HI survey of the Bootes void and compare the distribution and HI properties of the void galaxies to those of galaxies found in a survey of regions of mean cosmic density. The Bootes survey covers 1100 Mpc^{3}, or \\sim 1\\% of the volume of the void and consists of 24 cubes of typically 2 Mpc * 2 Mpc * 1280 km/s, centered on optically known galaxies. Sixteen targets were detected in HI; 18 previously uncataloged objects were discovered directly in HI. The control sample consists of 12 cubes centered on IRAS selected galaxies with FIR luminosities similar to those of the Bootes targets and located in regions of 1 to 2 times the cosmic mean density. In addition to the 12 targets 29 companions were detected in HI. We find that the number of galaxies within 1 Mpc of the targets is the same to within a factor of two for void and control samples, and thus that the small scale clustering of galaxies is the same in regions that differ by a factor of \\sim 6 in density on larger scales. A ...

  7. 一种新的烧写BootLoader的方法%New Method of Burning BootLoader

    Institute of Scientific and Technical Information of China (English)

    顾明飞

    2010-01-01

    介绍了以J-Link 烧写BootLoader 的方法,利用s3c2440内部集成的4k Sram(steppingstone)运行特制程序初始化SDRAM并使其可用,再把支持NandFlash烧写功能的特制Uboot下载到SDRAM运行,达到通过间接的方法烧写NandFlash的目的,使没有并口的计算机也可烧写BootLoader.设计的方法易于应用,可简化嵌入式系统开发.

  8. Quasiperpendicular high Mach number Shocks

    CERN Document Server

    Sulaiman, A H; Dougherty, M K; Burgess, D; Fujimoto, M; Hospodarsky, G B

    2015-01-01

    Shock waves exist throughout the universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasi-perpendicular shocks across two orders of magnitude in Alfven Mach number (MA) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted timescale of ~0.3 {\\tau}c, where {\\tau}c is the ion gyroperio...

  9. An H I survey of the Bootes void .2. The analysis

    NARCIS (Netherlands)

    Szomoru, A; vanGorkom, JH; Gregg, MD; Strauss, MA

    1996-01-01

    We discuss the results of a VLA(2) [Napier et al., Proc. IEEE 71, 1295 (1983)] H I survey of the Bootes void and compare the distribution and H I properties of the void galaxies to those of galaxies found in a survey of regions of mean cosmic density. The Bootes survey covers 1100 Mpc(3), or similar

  10. Simulation-based otolaryngology - head and neck surgery boot camp: 'how I do it'.

    Science.gov (United States)

    Chin, C J; Chin, C A; Roth, K; Rotenberg, B W; Fung, K

    2016-03-01

    In otolaryngology, surgical emergencies can occur at any time. An annual surgical training camp (or 'boot camp') offers junior residents from across North America the opportunity to learn and practice these skills in a safe environment. The goals of this study were to describe the set-up and execution of a simulation-based otolaryngology boot camp and to determine participants' confidence in performing routine and emergency on-call procedures in stressful situations before and after the boot camp. There were three main components of the boot camp: task trainers, simulations and an interactive panel discussion. Surveys were given to participants before and after the boot camp, and their confidence in performing the different tasks was assessed via multiple t-tests. Participants comprised 22 residents from 12 different universities; 10 of these completed both boot camp surveys. Of the nine tasks, the residents reported a significant improvement in confidence levels for six, including surgical airway and orbital haematoma management. An otolaryngology boot camp gives residents the chance to learn and practice emergency skills before encountering the emergencies in everyday practice. Their confidence in multiple skillsets was significantly improved after the boot camp. Given the shift towards competency-based learning in medical training, this study has implications for all surgical and procedural specialties.

  11. Optimization of CernVM early boot process

    CERN Document Server

    Mazdin, Petra

    2015-01-01

    CernVM virtual machine is a Linux based virtual appliance optimized for High Energy Physics experiments. It is used for cloud computing, volunteer computing, and software development by the four large LHC experiments. The goal of this project is proling and optimizing the boot process of the CernVM. A key part was the development of a performance profiler for shell scripts as an extension to the popular BusyBox open source UNIX tool suite. Based on the measurements, costly shell code was replaced by more efficient, custom C programs. The results are compared to the original ones and successful optimization is proven.

  12. Nasal cancer in the Northamptonshire boot and shoe industry.

    Science.gov (United States)

    Acheson, E D; Cowdell, R H; Jolles, B

    1970-02-14

    A survey of the incidence of nasal cancer in Northamptonshire during the period 1953 to 1967 is reported. Of the 46 patients with nasal cancer ascertained during the 15-year period 21 (19 males and 2 females) had been employed at some time in the boot and shoe industry. Five other cases diagnosed either before 1953 or after 1967 in persons who had worked in the boot and shoe industry in Northamptonshire were ascertained from various sources.The incidence of nasal cancer (all histological types considered together) was significantly higher in male boot and shoe operatives in Northamptonshire than in males of all occupational classes in the Cancer Register areas selected for comparison and in males working in other occupations in Northamptonshire. The excess incidence has recently given rise to the occurrence of between 1 and 2 new cases per annum in the Northamptonshire boot and shoe industry.The cases within the Northamptonshire industry occurred almost entirely in the relatively small number of workers who are exposed to the dust of the materials used in the manufacture of footwear.Possibly there are two carcinogenic factors in the industry-one related to the production of nasal adenocarcinoma, and the other to squamous and possibly other types of carcinoma in the nasal cavity and sinuses. This requires further study. Our best estimate of the latent period for the adenocarcinoma cases was 54.6 years, which is substantially longer than for the patients with squamous, transitional, and anaplastic tumours (41.7 years). We have no evidence to answer the question whether the facts are still present in the industrial environment, though undoubtedly the standards of hygiene in the industry has improved substantially since these men were first exposed.There is probably an increased risk of nasal adenocarcinoma in the footwear repairing industry, but this requires further study. Our evidence suggests that snuff taking should be considered as a possible contributory factor

  13. Stored-grain insect population commingling densities in wheat and corn from pilot-scale bucket elevator boots

    Science.gov (United States)

    Grain elevator boot and pit areas facilitate the commingling of insects with the grain moving through the elevator leg. A removable boot was developed to facilitate residual grain removal and preservation in the boot and to quantify the commingling magnitude as a function of stored-product insect de...

  14. Versatile retraction mechanics: Implant assisted en-masse retraction with a boot loop

    Directory of Open Access Journals (Sweden)

    Pramod Philip

    2015-01-01

    Full Text Available The purpose of this paper is to explain the versatility offered by the use of arch wires with boot loops in retraction mechanics while taking direct anchorage from mini-screws. Materials and Methods: The materials include the mini screws placed at the appropriate location and retraction arches made of 0.019 X 0.025 SS with boot loops placed distal to the lateral incisors. Mini screw provides a stable anchorage for enmasse retraction of the anterior teeth with the help of a boot loop using sliding and/or loop mechanics. Results: The arch wires with boot loops have a definite advantage over the soldered/ crimpable hooks because of the versatility it offers during the process of retraction. Conclusion: An innovative approach combining the advantages of absolute anchorage using mini implants and a retraction arch with boot loop is presented here.

  15. Materials, Designs and Standards Used in Ski-Boots for Alpine Skiing

    Directory of Open Access Journals (Sweden)

    Matteo Moncalero

    2013-10-01

    Full Text Available This review article reports the recent advances in the study, design and production of ski-boots for alpine skiing. An overview of the different designs and the materials used in ski-boot construction is provided giving particular emphasis to the effect of these parameters on the final performances and on the prevention of injuries. The use of specific materials for ski-boots dedicated to different disciplines (race skiing, mogul skiing, ski-mountaineering etc. has been correlated with the chemical and physical properties of the polymeric materials employed. A review of the scientific literature and the most interesting patents is also presented, correlating the results reported with the performances and industrial production of ski-boots. Suggestions for new studies and the use of advanced materials are also provided. A final section dedicated to the standards involved in ski-boot design completes this review article.

  16. Quasiperpendicular High Mach Number Shocks

    Science.gov (United States)

    Sulaiman, A. H.; Masters, A.; Dougherty, M. K.; Burgess, D.; Fujimoto, M.; Hospodarsky, G. B.

    2015-09-01

    Shock waves exist throughout the Universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this Letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasiperpendicular shocks across 2 orders of magnitude in Alfvén Mach number (MA ) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted time scale of ˜0.3 τc , where τc is the ion gyroperiod. In addition, we experimentally reveal the relationship between reformation and MA and focus on the magnetic structure of such shocks to further show that for the same MA , a reforming shock exhibits stronger magnetic field amplification than a shock that is not reforming.

  17. The BOOTES-5 telescope at San Pedro Martir National Astronomical Observatory, Mexico

    Science.gov (United States)

    Hiriart, D.; Valdez, J.; Martínez, B.; García, B.; Cordova, A.; Colorado, E.; Guisa, G.; Ochoa, J. L.; Nuñez, J. M.; Ceseña, U.; Cunniffe, R.; Murphy, D.; Lee, W.; Park, Il H.; Castro-Tirado, A. J.

    2016-12-01

    BOOTES-5 is the fifth robotic observatory of the international network of robotic telescopes BOOTES (Burst Observer and Optical Transient Exploring Optical System). It is located at the National Astronomical Observatory at Sierra San Pedro Martir, Baja California, Mexico. It was dedicated on November 26, 2015 and it is in the process of testing. Its main scientific objective is the observation and monitoring of the optic counterparts of gamma-ray bursts as quickly as possible once they have been detected from space or other ground-based observatories. BOOTES-5 fue nombrado Telescopio Javier Gorosabel en memoria del astrónomo español Javier Gorosabel Urkia.

  18. Writing Together to Get AHEAD: an interprofessional boot camp to support scholarly writing in the health professions.

    Science.gov (United States)

    von Isenburg, Megan; Lee, Linda S; Oermann, Marilyn H

    2017-04-01

    Writing for publication is an integral skill for both sharing research findings and career advancement, yet many faculty lack expertise, support, and time to author scholarly publications. Health professions educators identified writing as an area in which a new educators' academy could offer support. To address this need, a writing task force was formed consisting of a librarian, a School of Medicine faculty member, and a School of Nursing faculty member. The task force launched two initiatives to motivate and support faculty writing and publication over two academic years. In the first year, a structured interprofessional "boot camp" consisting of a sequenced, modularized approach to manuscript completion was offered. In the second year, community building, in-person writing sessions, and incentives were added to the structured tasks. In year one, twenty participants enlisted in the boot camp, nine of whom completed a manuscript for submission by the end of the program. Qualitative feedback indicated potential improvements, which were put in place in the second program. In year two, twenty-eight participants enrolled, and eleven submitted thirteen manuscripts for publication by the end of the program. Structured tasks, frequent deadlines, and professional editorial assistance were highly valued by participants. Time remains a barrier for faculty seeking to complete manuscripts. As experts in many facets of the publication process, librarians are well positioned to partner with others to facilitate faculty and staff development in writing.

  19. Physical parameters of seven field RR Lyrae Stars in Bootes

    CERN Document Server

    Peña, J H; Miller, R Peña; Sareyan, J P; Alvarez, M

    2009-01-01

    Str\\"omgren uvby-beta photometry is reported for the RR Lyrae stars AE, RS, ST, TV, TW, UU, and XX in Bootes. The physical parameters M/Mo, log (L/Lo), M_V, log T_eff and [Fe/H], have been estimated from the Fourier decomposition of the light curves and the empirical calibrations developed for this type of stars. Detailed behavior of the stars along the cycle of pulsation has been determined from the observed photometric indices and the synthetic indices from atmospheric models. The reddening of the zone is found to be negligible, as estimated from the reddening of several objects in the same region of the sky. Hence the distances to the individual objects are also estimated.

  20. Radio-loud high-redshift protogalaxy canidates in Bootes

    Energy Technology Data Exchange (ETDEWEB)

    Croft, S; van Breugel, W; Brown, M J; de Vries, W; Dey, A; Eisenhardt, P; Jannuzi, B; Rottgering, H; Stanford, S A; Stern, D; Willner, S P

    2007-07-20

    We used the Near Infrared Camera (NIRC) on Keck I to obtain K{sub s}-band images of four candidate high-redshift radio galaxies selected using optical and radio data in the NOAO Deep Wide-Field Survey in Bootes. Our targets have 1.4 GHz radio flux densities greater than 1 mJy, but are undetected in the optical. Spectral energy distribution fitting suggests that three of these objects are at z > 3, with radio luminosities near the FR-I/FR-II break. The other has photometric redshift z{sub phot} = 1.2, but may in fact be at higher redshift. Two of the four objects exhibit diffuse morphologies in K{sub s}-band, suggesting that they are still in the process of forming.

  1. Extended stellar substructure surrounding the Bo\\"otes I dwarf spheroidal galaxy

    CERN Document Server

    Roderick, T A; Jerjen, H; Da Costa, G S

    2016-01-01

    We present deep stellar photometry of the Bo\\"otes I dwarf spheroidal galaxy in g and i band filters, taken with the Dark Energy Camera at Cerro Tololo in Chile. Our analysis reveals a large, extended region of stellar substructure surrounding the dwarf, as well as a distinct over-density encroaching on its tidal radius. A radial profile of the Bo\\"otes I stellar distribution shows a break radius indicating the presence of extra-tidal stars. These observations strongly suggest that Bo\\"otes I is experiencing tidal disruption, although not as extreme as that exhibited by the Hercules dwarf spheroidal. Combined with revised velocity dispersion measurements from the literature, we see evidence suggesting the need to review previous theoretical models of the Bo\\"otes I dwarf spheroidal galaxy.

  2. A Decade of GRB Follow-Up by BOOTES in Spain (2003–2013

    Directory of Open Access Journals (Sweden)

    Martin Jelínek

    2016-01-01

    Full Text Available This article covers ten years of GRB follow-ups by the Spanish BOOTES stations: 71 follow-ups providing 23 detections. Follow-ups by BOOTES-1B from 2005 to 2008 were given in a previous article and are here reviewed and updated, and additional detection data points are included as the former article merely stated their existence. The all-sky cameras CASSANDRA have not yet detected any GRB optical afterglows, but limits are reported where available.

  3. A decade of GRB follow-up by BOOTES in Spain (2003-2013)

    CERN Document Server

    Jelínek, Martin; Cunniffe, Ronan; Gorosabel, Javier; Vítek, Stanislav; Kubánek, Petr; Postigo, Antonio de Ugarte; Guziy, Sergey; Tello, Juan C; Páta, Petr; Sánchez-Ramírez, Rubén; Oates, Samantha; Jeong, Soomin; Štrobl, Jan; Castillo-Carrión, Sebastián; Sanguino, Tomás Mateo; Rabaza, Ovidio; Pérez-Ramírez, Dolores; Fernández-Muñoz, Rafael; Carretero, Benito A de la Morena; Hudec, René; Reglero, Víctor; Sabau-Graziati, Lola

    2016-01-01

    This article covers ten years of GRB follow-ups by the Spanish BOOTES stations: 71 follow-ups providing 23 detections. Follow-ups by BOOTES-1B from 2005 to 2008 were given in the previous article, and are here reviewed, updated, and include additional detection data points as the former article merely stated their existence. The all-sky cameras CASSANDRA have not yet detected any GRB optical afterglows, but limits are reported where available.

  4. JuliBootS: a hands-on guide to the conformal bootstrap

    OpenAIRE

    Paulos, Miguel F.

    2014-01-01

    We introduce {\\tt JuliBootS}, a package for numerical conformal bootstrap computations coded in {\\tt Julia}. The centre-piece of {\\tt JuliBootS} is an implementation of Dantzig's simplex method capable of handling arbitrary precision linear programming problems with continuous search spaces. Current supported features include conformal dimension bounds, OPE bounds, and bootstrap with or without global symmetries. The code is trivially parallelizable on one or multiple machines. We exemplify u...

  5. INITIAL FOLLOW-UP OF OPTICAL TRANSIENTS WITH COLORES USING THE BOOTES NETWORK

    Directory of Open Access Journals (Sweden)

    Maria D. Caballero-Garcia

    2015-04-01

    Full Text Available The Burst Observer and Optical Transient Exploring System (BOOTES is a network of telescopes that allows the continuous monitoring of transient astrophysical sources. It was originally devoted to the study of the optical emissions from gamma-raybursts (GRBs that occur in the Universe. In this paper we show the initial results obtained using the spectrograph COLORES (mounted on BOOTES-2, when observing optical transients (OTs of a diverse nature.

  6. Clinical Boot Camp: An Innovative Simulation Experience to Prepare Nursing Students for Obstetric and Pediatric Clinicals.

    Science.gov (United States)

    Hogewood, Connie; Smith, Tedra; Etheridge, Sherita; Britt, Sylvia

    2015-01-01

    Obstetric and pediatric patients require unique specialized care not included in traditional adult health education. To prepare nursing students for clinical rotations beginning the second week of class, faculty developed an innovative one-day simulation seminar, the OB/PEDS Boot Camp, in which groups of students rotated through six stations of obstetric and pediatric simulation exercises. This article provides insight on the development and implementation of the OB/PEDS Boot Camp.

  7. Effect of rain boot shaft length on lower extremity muscle activity during treadmill walking

    Science.gov (United States)

    Kim, Young-Hwan; Yoo, Kyung-Tae

    2016-01-01

    [Purpose] This study aimed to determine the extent of lower extremity muscle activity before and after walking based on rain boot shaft length. [Subjects and Methods] The subjects, 12 young and healthy females, were divided into three groups based on rain boot shaft length (long, middle, and short). They walked on a treadmill for 30 minutes. Activity of the rectus femoris, vastus lateralis, semitendinosus, tibialis anterior, peroneus longus, and gastrocnemius was measured using electromyography before and after walking. Two-way repeated measures analysis of variance was performed to compare the muscle activities of each group. [Results] There were no significant differences in terms of the interactive effects between group and time for all muscles, the main effects of group, or the main effects of time. [Conclusion] The results of this study may indicate that movement of the lower extremities was not significantly limited by friction force based on the characteristics of the boot material or the circumference of the boot shaft. Thus, it may be helpful instead to consider the material of the sole or the weight of the boots when choosing which rain boots to wear. PMID:27799685

  8. MACH: Fast Randomized Tensor Decompositions

    CERN Document Server

    Tsourakakis, Charalampos E

    2009-01-01

    Tensors naturally model many real world processes which generate multi-aspect data. Such processes appear in many different research disciplines, e.g, chemometrics, computer vision, psychometrics and neuroimaging analysis. Tensor decompositions such as the Tucker decomposition are used to analyze multi-aspect data and extract latent factors, which capture the multilinear data structure. Such decompositions are powerful mining tools, for extracting patterns from large data volumes. However, most frequently used algorithms for such decompositions involve the computationally expensive Singular Value Decomposition. In this paper we propose MACH, a new sampling algorithm to compute such decompositions. Our method is of significant practical value for tensor streams, such as environmental monitoring systems, IP traffic matrices over time, where large amounts of data are accumulated and the analysis is computationally intensive but also in "post-mortem" data analysis cases where the tensor does not fit in the availa...

  9. Setup time reduction in pvc boots production through smed technique

    Directory of Open Access Journals (Sweden)

    Amanda Herculano da Costa

    2012-03-01

    Full Text Available The competition imposed by the market requires of the organizations the continuous improvement of its processes, products and offered services, with lower production costs. This article addresses this issue describing the resulting improvements from the implementation of Single Minute Exchange of Die (SMED in the process of exchange the mold of the injection machine of PVC during the boots manufacturing. The case study was conducted in a large company of footwear, located in the state of Paraiba. In order to find the best alternative to the problem of the setup of the molds, were used the SMED and the methodology for problem resolution, and then was implemented the solution that generated greater productivity for the company. Among the improvements made, we should emphasize the reduction of inactive time of 11.56 minutes to 5 minutes, reducing the time needed for the adjustments of the molds with the implementation of guides for centering and shims to standardize the heights of the molds.

  10. The Booting-Type ADRC of Airborne Photoelectrical Platform

    Directory of Open Access Journals (Sweden)

    Xiantao Li

    2014-01-01

    Full Text Available Customary disturbance rejection in the photoelectrical platform is “passive,” which makes it difficult to further improve the isolation degree owning to the strict restriction of mechanical resonance frequency. In this paper, a booting-type ADRC is proposed, whose disturbance estimation process is guided by target value to reduce the overshoot and lag in the estimated value of disturbance. All kinds of disturbance in the system are modeled in a unified way by using the equivalent disturbance voltage to avoid the complex modeling process. Based on the simplified model, extended state observer (ESO is designed to realize a real-time estimation of the disturbance. Then, the disturbance compensation is added to generate the final control value by combining the customary square lead-lag controller. Experiments are implemented to test the proposed control strategy by mounting the photoelectrical platform on a flight simulator and generating a motion perturbation. Compared with the case of only traditional lead-lag controller, the isolation degree of disturbance is enhanced obviously. And the experiments also illustrate strong robustness of ADRC.

  11. Can You Hack It? Validating Predictors for IT Boot Camps

    Science.gov (United States)

    Gear, Courtney C.

    Given the large number of information technology jobs open and lack of qualified individuals to fill them, coding boot camps have sprung up in response to this skill gap by offering a specialized training program in an accelerated format. This fast growth has created a need to measure these training programs and understand their effectiveness. In the present study, a series of analyses examined whether specific or combinations of predictors were valid for training performance in this coding academy. Self-rated, daily efficacy scores were used as outcome variables of training success and correlation results showed a positive relationship with efficacy scores and the logic test score as a predictor. Exploratory analyses indicated a Dunning-Kruger effect where students with lower education levels experience higher overall mood during the training program. Limitations of the study included small sample size, severe range restriction in predictor scores, lack of variance in predictor scores, and low variability in training program success. These limitations made identifying jumps between training stages difficult to identify. By identifying which predictors matter most for each stage of skill acquisition, further research should consider more objective variables such as instructor scores which can serve as a guideline to better asses what stage learners join at and how to design curriculum and assignments accordingly (Honken, 2013).

  12. Nearby groups of galaxies in the Hercules-Bootes constellations

    Science.gov (United States)

    Karachentsev, I. D.; Kashibadze, O. G.; Karachentseva, V. E.

    2017-04-01

    We consider a sample of 412 galaxies with radial velocities $V_{\\rm LG} sky region of ${\\rm RA}=13^h\\hspace{-0.4em}.\\,0$ ... $19^h\\hspace{-0.4em}.\\,0$, ${\\rm Dec}=+10^{\\circ}$ ... $+40^{\\circ}$ between the Local Void and the Supergalactic plane. One hundred and eighty-one of them have individual distance estimates. Peculiar velocities of the galaxies as a function of Supergalactic latitude SGB show signs of Virgocentric infall at $SGB 60^{\\circ}$. A half of the Hercules-Bootes galaxies belong to 17 groups and 29 pairs, with the richest group around NGC5353. A typical group is characterized by the velocity dispersion of $67$ km s$^{-1}$, the harmonic radius of $182$ kpc, the stellar mass of $4.3 \\times10^{10} M_{\\odot}$ and the virial-to-stellar mass ratio of $32$. The binary galaxies have the mean radial velocity difference of $37$ km s$^{-1}$, the projected separation of $96$ kpc, the mean integral stellar mass of $2.6\\times 10^9 M_{\\odot}$ and the mean virial-to-stellar mass ratio of about $8$. The total dark-matter-to-stellar mass ratio in the considered sky region amounts to $37$ being almost the same as that in the Local Volume.

  13. Finite element modeling of a 3D coupled foot-boot model.

    Science.gov (United States)

    Qiu, Tian-Xia; Teo, Ee-Chon; Yan, Ya-Bo; Lei, Wei

    2011-12-01

    Increasingly, musculoskeletal models of the human body are used as powerful tools to study biological structures. The lower limb, and in particular the foot, is of interest because it is the primary physical interaction between the body and the environment during locomotion. The goal of this paper is to adopt the finite element (FE) modeling and analysis approaches to create a state-of-the-art 3D coupled foot-boot model for future studies on biomechanical investigation of stress injury mechanism, foot wear design and parachute landing fall simulation. In the modeling process, the foot-ankle model with lower leg was developed based on Computed Tomography (CT) images using ScanIP, Surfacer and ANSYS. Then, the boot was represented by assembling the FE models of upper, insole, midsole and outsole built based on the FE model of the foot-ankle, and finally the coupled foot-boot model was generated by putting together the models of the lower limb and boot. In this study, the FE model of foot and ankle was validated during balance standing. There was a good agreement in the overall patterns of predicted and measured plantar pressure distribution published in literature. The coupled foot-boot model will be fully validated in the subsequent works under both static and dynamic loading conditions for further studies on injuries investigation in military and sports, foot wear design and characteristics of parachute landing impact in military.

  14. Chaotic behaviour of high Mach number flows

    Science.gov (United States)

    Varvoglis, H.; Ghosh, S.

    1985-01-01

    The stability of the super-Alfvenic flow of a two-fluid plasma model with respect to the Mach number and the angle between the flow direction and the magnetic field is investigated. It is found that, in general, a large scale chaotic region develops around the initial equilibrium of the laminar flow when the Mach number exceeds a certain threshold value. After reaching a maximum the size of this region begins shrinking and goes to zero as the Mach number tends to infinity. As a result high Mach number flows in time independent astrophysical plasmas may lead to the formation of 'quasi-shocks' in the presence of little or no dissipation.

  15. Mach, the Universe, and Foundations of Mechanics

    CERN Document Server

    Mashhoon, B

    2011-01-01

    Barbour's response to our recent paper on "Mach's principle and higher-dimensional dynamics" describes an approach to Mach's principle in which the universe as a whole is involved in the definition of inertial frames of reference. Moreover, Barbour's theoretical procedure is in agreement with general relativity for a finite universe that is spatially closed. However, we prefer an operational approach that relies ultimately on observational data.

  16. An Innovative Clinical Skills “Boot Camp” for Dental Medicine Residents

    Directory of Open Access Journals (Sweden)

    Jenny Castillo

    2017-05-01

    Full Text Available During a 1-year hospital-based residency, dental residents are required to rotate through many departments including surgery, medicine, and emergency medicine. It became apparent that there was a gap between clinical skills knowledge taught in dental school curriculum and skills required for hospital-based patient care. In response, a simulation-based intensive clinical skill “boot camp” was created. The boot camp provided an intensive, interactive 3-day session for the dental residents. During the 3 days, residents were introduced to medical knowledge and skills that were necessary for their inpatient hospital rotations but were lacking in traditional dental school curriculum. Effectiveness of the boot camp was assessed in terms of knowledge base and comfort through presession and postsession surveys. According to resident feedback, this intensive introduction for the dental residents improved their readiness for their inpatient hospital-based residency.

  17. Optimization of shearer sliding boots by plasma cladding with Cr4MnTi

    Institute of Scientific and Technical Information of China (English)

    Liu Hongtao; Wang Luping; Ge Shirong; Cao Shoufan; JinJing; Gao Jiping

    2011-01-01

    Severe production conditions in coal mines cause damage and failure problems with the oriented sliding boots of the mechanical shearer.Wear has been an especially vexing problem.Plasma cladding methods were used to study optimized sliding boot design.By cladding the substrate steel the surface may be made of a material more resistant to wear.The iron based alloy Cr4MnTi was coated onto a modified 45 steel matrix material in these tests.The results show that the alloy cladding layer is high strength,has high hardness,and is highly resistant to wear.After hardening and tempering,45 steel substrate has great tenacity so the combined structure meets the performance requirements for the construction of shearer sliding boots.

  18. Pemanfaatan minarex sebagai secondary plasticizer untuk pembuatan kompon sepatu boot PVC

    Directory of Open Access Journals (Sweden)

    Supraptiningsih Supraptiningsih

    1997-06-01

    Full Text Available The purpose of the research is to find out optimum amount of minarex (side product from Pertamina Jakarta as secondary plasticizer which can be added to PVS compound in order to obtain boots compound conforming to SII 1990-86: Sepatu boot PVC. Research yield is a slab made by hydraulic press machine. 1700 C and pressure 150 kg/cm2 and the time must be suitable with the thickness. From various types of minarex used for the research, four of them can be applied as secondary plasticizer at PVC compound for boots which conforms to SII 1909-89, i.e. minarex C type 2, minarex C type 3, minarex D type 3 for five parts each.

  19. Fenomenologia e fenomenismo em Husserl e Mach

    Directory of Open Access Journals (Sweden)

    Denis Fisette

    2009-12-01

    Full Text Available Como conciliar as repetidas críticas ao fenomenismo de Mach, um pouco por toda a obra de Husserl, com o papel proeminente que Husserl parece nele reconhecer em seus últimos trabalhos, quanto à gênese de sua própria fenomenologia? Para responder a essa questão, examinaremos, primeiramente, a relação estreita que Husserl estabelece entre o método fenomenológico e o descritivismo de Mach à luz do debate que opõe nativismo e empirismo sobre a origem da percepção do espaço. Em seguida, examinaremos dois aspectos da crítica que Husserl faz ao positivismo de Mach: o primeiro se refere ao fenomenismo e sua doutrina dos elementos, enquanto o segundo, ao princípio de economia de pensamento, que Husserl associa a uma forma de psicologismo em Prolegômenos. A hipótese que nos guiará nesse estudo é que as opiniões aparentemente contraditórias de Husserl sobre o positivismo de Mach se explicam em parte pelo estatuto duplo que a fenomenologia recebe em seus últimos trabalhos: enquanto programa filosófico, ela se opõe explicitamente ao positivismo; enquanto método, ela se aparenta ao descritivismo de Mach. Concluiremos com a ideia de que esses dois filósofos de origem checa perseguiam o objetivo comum de apreender o sentido originário de positividade.How to conciliate the recurrent criticisms to Mach's phenomenism, a bit in all Husserl's work, with the outstanding role Husserl seems to recognise in phenomenism in his last works, as to the genesis of his own phenomenology? In order to answer this question, we examine, first, the close relationship stablished by Husserl between the phenomenological method and Mach's descriptivism in light of the debate that opposes nativism and empiricism regarding the origin of the perception of space. Next, we examine two features of Husserl's criticism to Mach's positivism: the first refers to phenomenism ans its doctrine of elements, and the second, to the principle of economy of thought, which

  20. Impact of Anatomy Boot Camp on Students in a Medical Gross Anatomy Course.

    Science.gov (United States)

    Herling, Patrick J; Mohseni, B Tanya; Hill, Derek C; Chelf, Stacy; Rickert, Jeffrey A; Leo, Jonathan T; Langley, Natalie R

    2016-09-23

    Lincoln Memorial University-DeBusk College of Osteopathic Medicine (LMU-DCOM) offers an optional three-week summer Anatomy Boot Camp course (ABC) to facilitate students' transition into medical school and promote retention of anatomy subject matter. The pre-matriculation program is a supplemental instruction course that utilizes a small group learning format. Boot camp instruction is led by teaching assistants and two anatomy professors. Enrollees gain early exposure to Medical Gross Anatomy (MGA) course subject matter, which is taught in the fall semester, and learn study skills necessary to excel in medical school. No grade is assigned for the course, therefore participants can study without the fear of potentially affecting grades. This study evaluates the effectiveness of the LMU-DCOM ABC course using data from four consecutive summers. Independent two-sample t-tests were used to compare ABC to non-ABC students for the following variables: incoming grade point average (GPA) and Medical College Admission Test® (MCAT®) scores, MGA written and laboratory practical examination grades, and final MGA course grade. Additionally, a 26-question survey was administered to 2012-2014 boot camp participants. There were no significant differences in incoming GPA and MCAT scores. However, boot campers scored significantly higher on the first two lecture and laboratory examinations (P < 0.05) for each year of the study. Thereafter scores varied less, suggesting a faster head start for boot camp participants. Mean MGA final grade was on average 3% higher for the boot camp cohort. The survey feedback supports that the ABC course assists with the academic and social transition into medical school. Anat Sci Educ. © 2016 American Association of Anatomists.

  1. THE BOOTES-5 TELESCOPE AT SAN PEDRO MARTIR NATIONAL ASTRONOMICAL OBSERVATORY, MEXICO

    OpenAIRE

    David Hiriart; Jorge Valdez; Benjamín Martínez; Benjamín García; Antolín Cordova; Enrique Colorado; Gerardo Guisa; José Luís Ochoa; Juan Manuel Nuñez; Urania Ceseña; Ronan Cunniffe; David Murphy; William Lee; Park, Il H.; Alberto J. Castro\\u2013Tirado

    2016-01-01

    BOOTES-5 es el quinto observatorio rob ́otico de la red internacional de telescopios r ob ́oticos BOOTES (Burst Observer and Optical Transient Exploring System). Se encuentra ubicado en el Observatorio As tron ́omico Nacional en la sierra de San Pedro M ́artir, Baja California, M ́exico. Fue i naugurado el 26 de noviembre de 2015 y se encuentra en proceso de prueba. Su principal objetivo cient ́ıfico es la observaci ́on y seguimiento a la brevedad posible de las contrapartes ́opticas de los...

  2. JuliBootS: a hands-on guide to the conformal bootstrap

    CERN Document Server

    Paulos, Miguel F

    2014-01-01

    We introduce {\\tt JuliBootS}, a package for numerical conformal bootstrap computations coded in {\\tt Julia}. The centre-piece of {\\tt JuliBootS} is an implementation of Dantzig's simplex method capable of handling arbitrary precision linear programming problems with continuous search spaces. Current supported features include conformal dimension bounds, OPE bounds, and bootstrap with or without global symmetries. The code is trivially parallelizable on one or multiple machines. We exemplify usage extensively with several real-world applications. In passing we give a pedagogical introduction to the numerical bootstrap methods.

  3. National transonic facility Mach number system

    Science.gov (United States)

    Kern, F. A.; Knight, C. W.; Zasimowich, R. F.

    1985-01-01

    The Mach number system for the Langley Research Center's National Transonic Facility was designed to measure pressures to determine Mach number to within + or - 0.002. Nine calibration laboratory type fused quartz gages, four different range gages for the total pressure measurement, and five different range gages for the static pressure measurement were used to satisfy the accuracy requirement over the 103,000-890,000 Pa total pressure range of the tunnel. The system which has been in operation for over 1 year is controlled by a programmable data process controller to select, through the operation of solenoid valves, the proper range fused quartz gage to maximize the measurement accuracy. The pressure gage's analog outputs are digitized by the process controller and transmitted to the main computer for Mach number computation. An automatic two-point on-line calibration of the nine quartz gages is provided using a high accuracy mercury manometer.

  4. Disinfection of three wading boot surfaces infested with New Zealand mudsnails

    Science.gov (United States)

    Stockton, Kelly A.; Moffitt, Christine M.

    2013-01-01

    New Zealand mudsnails Potamopyrgus antipodarum (NZMS) have been introduced into many continents and are easily transported live while attached to wading and other field gear. We quantified the relative attachment by different life stages of NZMS to felt, neoprene, and rubber-soled boots exposed to two densities of NZMS in experimental exposure totes. Attachment by NZMS occurred on boots of all surfaces, but the highest numbers of all life stages occurred on boots with felt surfaces. We found a 15–20-min bath application of 20 g/L Virkon Aquatic was a reliable tool to disinfect boot surfaces infested with NZMS and other aquatic invertebrates. Our studies support that spray application of this disinfectant was not reliable to provide complete mortality of attached adult NZMS or neonates. Wading gear surfaces exposed to repeated bath disinfections showed little deterioration. Our results provide strong evidence that bath disinfections with Virkon Aquatic are helpful to assure biosecurity in field and hatchery settings, but applications should be coupled with cleaning procedures to remove organic materials that can deactivate the reagent.

  5. Impact of Anatomy Boot Camp on Students in a Medical Gross Anatomy Course

    Science.gov (United States)

    Herling, Patrick J.; Mohseni, B. Tanya; Hill, Derek C.; Chelf, Stacy; Rickert, Jeffrey A.; Leo, Jonathan T.; Langley, Natalie R.

    2017-01-01

    Lincoln Memorial University-DeBusk College of Osteopathic Medicine (LMU-DCOM) offers an optional three-week summer Anatomy Boot Camp course (ABC) to facilitate students' transition into medical school and promote retention of anatomy subject matter. The pre-matriculation program is a supplemental instruction course that utilizes a small group…

  6. Effects of a Developmental Boot Camp: Improving Student Performance on a College Placement Test

    Science.gov (United States)

    Hill, Heather H.

    2012-01-01

    Nationwide, students are entering college unprepared for college-level work. Recent high school graduates are placing into developmental courses at an alarming rate. The purpose of this research study is to examine the effect of a developmental boot camp on standardized placement test scores of students enrolling at a community college in North…

  7. Design, Manufacturing, and Commissioning of BIRCAM (Bootes InfraRed CAMera)

    OpenAIRE

    2010-01-01

    This paper covers the various aspect of design, manufacturing and commissioning of the infrared camera BIRCAM, installed at BOOTES-IR, the 60 cm robotic infrared telescope at Sierra Nevada Observatory (OSN, Granada, Spain). We describe how we achieved a quality astronomical image, moving from the scientific requirements.

  8. The response of the MiL-Lx leg fitted with combat boots under impact loading

    CSIR Research Space (South Africa)

    Pandelani, T

    2014-01-01

    Full Text Available ) or even a side-attack IED. This impact causes significant soft tissue and/or bony injuries, leading to a long recovery, medical complications and may require limb amputation if not mitigated [1]. The military boots which the occupants wear...

  9. PROPOSAL OF PHOTOMETRIC REVERBERATION MAPPING WITH BOOTES-4

    Directory of Open Access Journals (Sweden)

    Wei-Min Yi

    2014-01-01

    Full Text Available R e v e r b e r a t i o n m a p p i n g ( R M e s u n a t ́ e c n i c a p o d e r o s a p a r a m e d i r l a m a s a d e a g u j e r o s n e g r o s e n n ́ u c l e o s d e galaxias act ́ıvas (AGNs. Sin embargo los programas de RM cl ́asicos, que utilizan espectroscop ́ıa para moni- t o r e a r l a s l ́ ı n e a s d e e m i s i ́ o n d e l a r e g i ́ o n d e l i n e a s a n c h a s ( B L R , g e n e r a l m e n t e e s t ́ a n l i m i t a d o s s ́ o l o p a r a l o s a g u j e r o s n e g r o s s u p e r m a s i v o s c o n t e l e s c o p i o s d e l a c l a s e d e 2 - m . E n a ̃ n o s r e c i e n t e s , u n a v a n c e e x t r a o r d i n a r i o h a s i d o l o g r a d o c o n l a t ́ e c n i c a d e R M f o t o m ́ e t r i c a , q u e a b r e l a p u e r t a p a r a m e d i r e fi c i e n t e m e n t e e l t a m a ̃ n o d e l B L R y l a l u m i n o s i d a d r e s t a d a d e l a g a l a x i a a n fi t r i o n a , i n c l u s o c o n t e l e s c o p i o s p e q u e ̃ n o s . C o n s i d e r a n d o la disponibilidad de otros telescopios BOOTES alrededor del mundo, consideramos proponer colaboraciones i n t e r n a c i o n a l e s c o m o u n o d e l o s p r o g r a m a s d e m o n i t o r e o d e l a r g o p l a z o p a r a t e l e s c o p i o s r o b ́ o t i c o s.

  10. Mach bands change asymmetrically during solar eclipses.

    Science.gov (United States)

    Ross, John; Diamond, Mark R; Badcock, David R

    2003-01-01

    Observations made during two partial eclipses of the Sun show that the Mach bands on shadows cast by the Sun disappear and reappear asymmetrically as an eclipse progresses. These changes can be explained as due to changes in the shape of the penumbras of shadows as the visible portion of the Sun forms crescents of different orientation.

  11. Research of Embedded Soft PLC Operation System Based on Boot Loader Technology%基于Boot Loader技术的嵌入式软PLC运行系统研究

    Institute of Scientific and Technical Information of China (English)

    刘晓文; 刘强; 吕茂超

    2011-01-01

    According to principle that writing a Boot Loader program in single-chip microcomputer can realize on-line self-programming updating of ladder diagram of PLC by user, the paper introduced a design of Boot Loader program of ATmega128 based on PLC application. The program writes object code of ladder diagram of PLC into FLASH of single-chip microcomputer through RS232 interface with imitatingmitsubishi communication protocol. The experiment showed that it makes design of PLC application software be more flexible and improves development efficiency that applying Boot Loader in PLC to realize downloading and updating of ladder diagram.%根据在单片机上利用Boot Loader引导加载程序可以实现用户对PLC梯形图在线自编程更新的原理,介绍了一种基于PLC应用的ATmega128的Boot Loader程序的设计.该程序采用仿三菱通信协议将PLC梯形图目标代码通过RS232接口更新写入到单片机的FLASH中.实验表明,将Boot Loader应用于PLC实现梯形图的下载更新,使PLC应用软件设计更具灵活性,同时提高了开发效率.

  12. 基于ARM7TDMI的嵌入式系统BootLoader的设计与实现%The Design and Realization of BootLoader Based on Imbedded System of ARM7TDMI

    Institute of Scientific and Technical Information of China (English)

    汪金宝; 陶玉贵; 陈付龙

    2011-01-01

    After the ARM7TDMI core board is designed, the USB interface expanded and increased, and BootLoader principle analyzed, detailed analysis and sophisticated design in a series of key technologies such as the start mode, interrupt handling, hardware initialization, booting linux kernel, etc eventually lead to a BoatLoader that supports the U-disk-loading embedded linux system image. By comparing the experimental results of the analysis, the BootLoader will better meet the requirements of users and developers.%通过设计ARM7TDMI核心板,扩展和增加USB接口,分析BootLoader原理,以及在启动模式、中断处理、硬件初始化和最终引导linux内核上的一系列关键技术,最终实现了一个支持从U盘加载嵌入式linux系统镜像的BootLoader,通过对实验结果的分析,该BootLoader能更好地满足用户和开发人员的要求.

  13. Effect of firefighter boots and viscoelastic insoles on the impact force of the ground reaction force’s vertical component

    Directory of Open Access Journals (Sweden)

    Jesús Cámara-Tobalina

    2011-12-01

    Full Text Available The aims of the present study were to determine the effect of firefighter's boots on the vertical component of the ground reaction force (GRF at heel strike, also known as heel strike transient and to analyze the effect of the viscoelastic insoles placed into the firefighter’s boots on this force during the gait. The magnitude of the impact force (FZI from the vertical ground reaction force, the time to the production of this force (TZI and the loading rate (GC were registered. 39 firefighters without any pathology during 2 years before the study were recruited. Three different walking conditions were tested: 1 gait with firefighter's boots, 2 gait with firefighter's boots and viscoelastic insoles and 3 gait with sport shoes. The results showed a higher production and magnitude of the impact force during gait with firefighter's boots than during gait with sport shoes (13,1 vs. 2,6 % of occurrence of the impact force and 61,39 ± 35,18 %BW (body weight vs. 49,38 ± 22,99 %BW, respectively. The gait with viscoelastic insoles placed into the firefighter's boots did not show significant differences in any of the parameters characterizing the impact force compared to the gait without insoles. The results of this study show a lower cushioning of the impact force during the gait with firefighter's boots in comparison to the gait with sport shoes and the inefficiency of the viscoelastic insoles placed inside the firefighter's boots to ameliorate the cushioning of the impact force at natural walking speed.

  14. First results from the Burst Observer and Optical Transient Exploring System station 1 (BOOTES-1)

    Science.gov (United States)

    Castro-Tirado, A. J.; Soldán, J.; Bernas, M.; Páta, P.; Hudec, R.; Sanguino, T. M.; de La Morena, B.; Berná, J. A.; de Ugarte, A.; Gorosabel, J.; Más-Hesse, J. M.; Giménez, A.

    2000-09-01

    The Burst Observer and Optical Transient Exploring System (BOOTES) is considered as a part of the preparations for ESA's INTEGRAL satellite, and is currently being developed in Spain, in collaboration with two Czech institutions. It makes use of two sets of wide-field cameras, 240 km apart, and two robotic 0.3-m telescopes. The first observing station (BOOTES-1) is located in Huelva (Spain) and the first light was obtained in July 1998. During the test phase, it has provided rapid follow-up observations with the wide-field cameras for 19 GRBs detected by BATSE aboard CGRO, and narrow-field imaging for 6 bursts. Limiting magnitudes for any GRB optical afterglow are I~13 and R~16.5, a few minutes after the events. .

  15. Boots of Leather, Slippers of Gold: The History of a Lesbian Community

    Directory of Open Access Journals (Sweden)

    Maria Chiara Ferro

    2016-03-01

    Full Text Available Elizabeth Lapovsky Kennedy, Madeline D. Davis, Boots of Leather, Slippers of Gold: The History of a Lesbian Community (1993. New York: Routledge, 2014.   La recensione sottolinea la rilevanza del volume Boots of Leather, Slippers of Gold a vent’anni dalla pubblicazione, sia perché raccoglie e preserva testimonianze di butches e femmes degli anni ’40 e ’50, sia perché chiarisce il ruolo sociale della comunità butch-femme in quanto sede di resistenza pre-politica. Inoltre, si evidenzia l’utilità di modelli interpretativi informati dagli studi queer e transgender nell’ambito della ricerca storica su identità non normative come quelle butch e femme.

  16. Information and Communication Technology: Design, Delivery, and Outcomes from a Nursing Informatics Boot Camp

    Science.gov (United States)

    Kleib, Manal; Simpson, Nicole; Rhodes, Beverly

    2016-05-31

    Information and communication technology (ICT) is integral in today’s healthcare as a critical piece of support to both track and improve patient and organizational outcomes. Facilitating nurses’ informatics competency development through continuing education is paramount to enhance their readiness to practice safely and accurately in technologically enabled work environments. In this article, we briefly describe progress in nursing informatics (NI) and share a project exemplar that describes our experience in the design, implementation, and evaluation of a NI educational event, a one-day boot camp format that was used to provide foundational knowledge in NI targeted primarily at frontline nurses in Alberta, Canada. We also discuss the project outcomes, including lessons learned and future implications. Overall, the boot camp was successful to raise nurses’ awareness about the importance of informatics in nursing practice.

  17. 一种新的烧写BootLoader的方法

    Institute of Scientific and Technical Information of China (English)

    顾明飞

    2010-01-01

    介绍了以J-Link烧写Boot Loader的方法,利用s3c2440内部集成的4k Sram(stepping stone)运行特制程序初始化SDRAM并使其可用,再把支持Nand Flash烧写功能的特制Uboot下载到SDRAM运行,达到通过间接的方法烧写Nand Flash的目的,使没有并口的计算机也可烧写Boot Loader。设计的方法易于应用,可简化嵌入式系统开发。

  18. On Mach's critique of Newton and Copernicus

    CERN Document Server

    Hartman, H I; Hartman, Herbert I.; Nissim-Sabat, Charles

    2003-01-01

    Maintaining the relativity of all motion, especially rotational motion, Mach denied the existence of absolute motion and absolute space. He maintained the equivalence of the Ptolemaic and the Copernican systems and the equivalence of a fixed bucket in a rotating universe with the converse. An analysis of the Foucault pendulum shows that there cannot be a fixed bucket in a rotating universe. Also, Mach's views violate the physics he espoused: non-inertial experiments, e.g. stellar aberration and electromagnetic effects, distinguish between a rotating bucket in a fixed universe and the converse, between the Copernican and the Ptolemaic systems, and establish that one cannot ascribe all observations solely to relative motion between a system and the universe.

  19. Low Mach Number Fluctuating Hydrodynamics for Electrolytes

    CERN Document Server

    Péraud, Jean-Philippe; Chaudhri, Anuj; Bell, John B; Donev, Aleksandar; Garcia, Alejandro L

    2016-01-01

    We formulate and study computationally the low Mach number fluctuating hydrodynamic equations for electrolyte solutions. We are interested in studying transport in mixtures of charged species at the mesoscale, down to scales below the Debye length, where thermal fluctuations have a significant impact on the dynamics. Continuing our previous work on fluctuating hydrodynamics of multicomponent mixtures of incompressible isothermal miscible liquids (A. Donev, et al., Physics of Fluids, 27, 3, 2015), we now include the effect of charged species using a quasielectrostatic approximation. Localized charges create an electric field, which in turn provides additional forcing in the mass and momentum equations. Our low Mach number formulation eliminates sound waves from the fully compressible formulation and leads to a more computationally efficient quasi-incompressible formulation. We demonstrate our ability to model saltwater (NaCl) solutions in both equilibrium and nonequilibrium settings. We show that our algorithm...

  20. The $z < 1.2$ optical luminosity function from a sample of $\\sim410 \\, 000$ galaxies in bootes

    CERN Document Server

    Beare, Richard A; Pimbblet, Kevin A; Bian, Fuyan; Lin, Yen-Ting

    2015-01-01

    Using a sample of ~410 000 galaxies to depth I_AB = 24 over 8.26 deg^2 in the Bootes field (~10 times larger than z~1 luminosity function studies in the prior literature), we have accurately measured the evolving B-band luminosity function of red galaxies at z<1.2 and blue galaxies at z<1.0. In addition to the large sample size, we utilise photometry that accounts for the varying angular sizes of galaxies, photometric redshifts verified with spectroscopy, and absolute magnitudes that should have very small random and systematic errors. Our results are consistent with the migration of galaxies from the blue cloud to the red sequence as they cease to form stars, and with downsizing in which more massive and luminous blue galaxies cease star formation earlier than fainter less massive ones. Comparing the observed fading of red galaxies with that to be expected from passive evolution alone, we find that the stellar mass contained within the red galaxy population has increased by a factor of ~3.6 from z~1.1 ...

  1. Ernst Mach a deeper look : documents and new perspectives

    CERN Document Server

    1992-01-01

    Ernst Mach -- A Deeper Look has been written to reveal to English-speaking readers the recent revival of interest in Ernst Mach in Europe and Japan. The book is a storehouse of new information on Mach as a philosopher, historian, scientist and person, containing a number of biographical and philosophical manuscripts publihsed for the first time, along with correspondence and other matters published for the first time in English. The book also provides English translations of Mach's controversies with leading physicists and psychologists, such as Max Planck and Carl Stumpf, and offers basic evidence for resolving Mach's position on atomism and Einstein's theory of relativity. Mach's scientific, philosophical and personal influence in a number of countries -- Austria, Germany, Bohemia and Yugoslavia among them -- has been carefully explored and many aspects detailed for the first time. All of the articles are eminently readable, especially those written by Mach's sister. They are deeply researched, new interpre...

  2. Gamma-Ray Burst Follow Up Observations with BOOTES in 1998--2000

    Science.gov (United States)

    Cerón, J. M. Castro; Castro-Tirado, A. J.; Hudec, R.; Soldán, J.; Bernas, M.; Páta, P.; Sanguino, T. J. Mateo; Postigo, A. De Ugarte; Berná, J. Á.; Nekola, M.; Gorosabel, J.; Morena, B. A. De La; Más-Hesse, J. M.; Giménez, Á.; Riera, J. Torres

    The Burst Observer and Optical Transient Exploring System (BOOTES) provides an automated realtime observing response to the detection of Gamma Ray Bursts (GRBs). Error box size depending, it uses wide field cameras attached to small robotic telescopes or the telescopes themselves. To date we have acquired photometry for about 30 events with the Ultra Wide (UWFC) and the Narrow Field Cameras (NFC) and about 50 events with the Wide Field Camera (WFC).

  3. A Radical New Mach 7 Engine

    Institute of Scientific and Technical Information of China (English)

    履之

    1994-01-01

    Most engines compress air, add fuel and burn it, and then allow theheated gas to expand, creating power or thrust. A radical aircraft enginedevised by ONERA, France’s equivalent of NASA, does the opposite.The Priam inverse-cycle" engine is designed for hypersonic speedsabove Mach 4 (2, 650 mph). Conventional jets do not work at suchspeeds, because the air becomes so hot when it is rammed into the

  4. Mach's Principle and Higher-Dimensional Dynamics

    CERN Document Server

    Mashhoon, B

    2011-01-01

    We briefly discuss the current status of Mach's principle in general relativity and point out that its last vestige, namely, the gravitomagnetic field associated with rotation, has recently been measured for the earth in the GP-B experiment. Furthermore, in his analysis of the foundations of Newtonian mechanics, Mach provided an operational definition for inertial mass and pointed out that time and space are conceptually distinct from their operational definitions by means of masses. Mach recognized that this circumstance is due to the lack of any a priori connection between the inertial mass of a body and its Newtonian state in space and time. One possible way to improve upon this situation in classical physics is to associate mass with an extra dimension. Indeed, Einstein's theory of gravitation can be locally embedded in a Ricci-flat 5D manifold such that the 4D energy-momentum tensor appears to originate from the existence of the extra dimension. An outline of such a 5D Machian extension of Einstein's gen...

  5. Slow light Mach-Zehnder fiber interferometer

    Institute of Scientific and Technical Information of China (English)

    Yundong Zhang; Jinfang Wang; Xuenan Zhang; Hao Wu; Yuanxue Cai; Jing Zhang; Ping Yuan

    2012-01-01

    A slow light structure Mach-Zehnder fiber interferometer is theoretically demonstrated.The sensitivity of the interferometer is significantly enhanced by the dispersion of the slow light structure.The numerical results show that the sensitivity enhancement factor varies with the coupling coefficient and reaches its maximum under critical coupling conditions.Interferometers have been investigated in relation to their applications in fields such as metrology[1],optical sensing[2],optical communication[3,4],quantum information processing[5],and biomedical engineering[6].A number of schemes have been proposed to improve the performance of interferometers[7],such as using photonic crystal structures to minimize the size of on-chip devices[8],utilizing the dispersive property of semiconductor to enhance the spectral sensitivity of interferometers[9,10],utilizing slow light medium to enhance the resolution of Fourier transform interferometer[11],exploiting fast light medium or slow light structure to increase the rotation sensitivity of a Sagnac interferometer[12,13],enhancing the transmittance of the Mach-Zehnder interferometer (MZI) in the slow light region by gratings[14],and using liquid crystal light valve to derive high sensitivity interferometers[15].%A slow light structure Mach-Zehnder fiber interferometer is theoretically demonstrated. The sensitivity of the interferometer is significantly enhanced by the dispersion of the slow light structure. The numerical results show that the sensitivity enhancement factor varies with the coupling coefficient and reaches its maximum under critical coupling conditions.

  6. Two years of gamma-ray burst follow up observations with BOOTES-1

    Science.gov (United States)

    Castro Cerón, José María; Castro-Tirado, Alberto J.; Soldán, Jan; Hudec, René; Bernas, Martin; Páta, Petr; Mateo Sanguino, Tomás De Jesús; de Ugarte Postigo, Antonio; Berná, José Angel; Nekola, Martin; Gorosabel, Javier; de La Morena, Benito A.; Más-Hesse, J. Miguel; Giménez, Alvaro; Torres Riera, José

    2001-09-01

    The Burst Observer and Optical Transient Exploring System exeriment (BOOTES) is designed to provide a real time observing response to the detection of Gamma Ray bursts (GRBs) using wide field cameras imaging in the I, R and V bands and, later on, deeper imaging with small robotic telescopes. It is part, within the framework of a Spanish-Czech collaboration, of a wide ongoing effort to prepare for ESA's satellite INTEGRAL. We provide a brief technical description of BOOTES. Furthermore, a table listing the results for the BOOTES 1B-Narrow Field Camera (1B-NFC), of near simultaneous observations and others, starting 5 minutes after the events, is given since first light (July 98). Additionally we discuss other scientific objectives (regular monitoring of selected objects like variable stars, nearby galaxies and bright QSOs/AGNs for flaring behaviour) and results. To date we have obtained images for about 30 events with the 1B-NFC. In one of the last searches we detected an optical transient, candidate to be the optical counterpart of the GRB 000313, although such relation has not been established to absolute certainty yet.

  7. Numerical simulation of Mach reflection of cellular detonations

    Science.gov (United States)

    Li, J.; Lee, J. H. S.

    2016-09-01

    The Mach reflection of cellular detonation waves on a wedge is investigated numerically in an attempt to elucidate the effect of cellular instabilities on Mach reflection, the dependence of self-similarity on the thickness of a detonation wave, and the initial development of the Mach stem near the wedge apex. A two-step chain-branching reaction model is used to give a thermally neutral induction zone followed by a chemical reaction zone for the detonation wave. A sufficiently large distance of travel of the Mach stem is computed to observe the asymptotic behavior in the far field. Depending on the scale at which the Mach reflection process occurs, it is found that the Mach reflection of a cellular detonation behaves essentially in the same way as a planar ZND detonation wave. The cellular instabilities, however, cause the triple-point trajectory to fluctuate. The fluctuations are due to interactions of the triple point of the Mach stem with the transverse waves of cellular instabilities. In the vicinity of the wedge apex, the Mach reflection is found to be self-similar and corresponds to that of a shock wave of the same strength, since the Mach stem is highly overdriven initially. In the far field, the triple-point trajectory approaches a straight line, indicating that the Mach reflection becomes self-similar asymptotically. The distance of the approach to self-similarity is found to decrease rapidly with decreasing thickness of the detonation front.

  8. Improvements to the implementation method of U-Boot supporting boot from multiple flashes%支持多种闪存启动的U-Boot实现方法的改进

    Institute of Scientific and Technical Information of China (English)

    卞芸; 王波

    2012-01-01

    The standard U-Boot does not support boot from NAND Flash yet at present,and the existing method of enabling U-Boot to boot from NAND Flash cannot recognize new NAND Flash with large pagesize and does not perform the bad block detection.To solve the above problems,this paper presents a general method of acquiring the pagesize and blocksize information of NAND Flash, and implements the function of detecting bad blocks.Furthermore,this paper presents an improvement to the existing method of automatically identifying whether the system are booting from NOR Flash or from NAND Flash after power on.After modifying and porting the U-Boot-2010.09 to mini2440 development board which is based on S3C2440A processor,the running result shows that UBoot supporting dual-boot from NOR and NAND Flash has been implemented,and the function of U-Boot has been extended.%标准的U-Boot目前不支持从NAND Flash启动,而现有的修改U-Boot实现从NAND Flash启动的方法无法识别新的大页NAND Flash,也没有进行坏块检测。针对上述问题,提出获取NAND Flash页大小和块大小信息的通用方法,并实现了坏块检测功能。此外,对现有的上电后自动识别系统是从NOR还是从NAND Flash启动的方法进行了改进。将U-Boot-2010.09修改并移植到基于S3C2440A处理器的mini2440开发板上,运行结果表明,实现了U-Boot从NOR和NAND Flash的双启动,扩展了U-Boot的功能。

  9. Impact of compression therapy using Unna's boot on the self-esteem of patients with venous leg ulcers.

    Science.gov (United States)

    Salome, G M; de Brito, M J A; Ferreira, L M

    2014-09-01

    To assess self-esteem in patients with venous leg ulcers treated with Unna's boot. • A descriptive, analytic, clinical study was conducted from June 2010 to May 2011 in an outpatient wound care clinic in São Paulo, Brazil. Patients of both sexes, aged ≥18 years, who had had a venous leg ulcer for more than one year and a Doppler ankle brachial index ranging from 0.8-1.0 were consecutively selected for inclusion. Patients were treated with wound dressings and Unna's boot. Self-esteem was assessed using the Brazilian version of the Rosenberg Self-Esteem Scale (RSE) at inclusion (baseline) and after 4, 8, and 12 months of compression therapy using Unna's boot. The scale is reverse-scored; thus lower scores indicate higher levels of self-esteem. • The patients showed a slight but significant improvement in self-esteem after 4 months of treatment (mean RSE score=17.12) compared with baseline (mean RSE score=24.90). However, a marked and significant improvement in self-esteem was observed after 8 months (mean RSE score=7.40) and 12 months (mean RSE score=2.10) of compression therapy using Unna's boot. • Patients with venous leg ulcers treated with Unna's boot for 12 months showed a significant improvement in self-esteem • All authors declare that no competing financial interests exist. There was no external funding for this study.

  10. On Mach's principle: Inertia as gravitation

    CERN Document Server

    Martín, J; Tiemblo, A; Ranada, Antonio F.

    2007-01-01

    In order to test the validity of Mach's principle, we calculate the action of the entire universe on a test mass in its rest frame, which is an acceleration ${\\bf g}^*$. We show the dependence of the inertia principle on the lapse and the shift. Using the formalism of linearized gravitation, we obtain the non-relativistic limit of ${\\bf g}^*$ in terms of two integrals. We follow then two approaches. In the first one, these integrals are calculated in the actual time section $t=t_0$ up to the distance $R_U=ct_0$. In the more exact and satisfactory second approach, they are calculated over the past light cone using the formalism of the retarded potentials. The aim is to find whether the acceleration $\\dot{\\bf v}$ in the LHS of Newton's second law can be interpreted as a reactive acceleration, in other words, as minus the acceleration of gravity ${\\bf g}^*$ in the rest frame of the accelerated particle ({\\it i. e.} to know whether or not ${\\bf g}^*=-\\dot{\\bf v}$). The results strongly support Mach's idea since t...

  11. Low Mach number fluctuating hydrodynamics for electrolytes

    Science.gov (United States)

    Péraud, Jean-Philippe; Nonaka, Andy; Chaudhri, Anuj; Bell, John B.; Donev, Aleksandar; Garcia, Alejandro L.

    2016-11-01

    We formulate and study computationally the low Mach number fluctuating hydrodynamic equations for electrolyte solutions. We are interested in studying transport in mixtures of charged species at the mesoscale, down to scales below the Debye length, where thermal fluctuations have a significant impact on the dynamics. Continuing our previous work on fluctuating hydrodynamics of multicomponent mixtures of incompressible isothermal miscible liquids [A. Donev et al., Phys. Fluids 27, 037103 (2015), 10.1063/1.4913571], we now include the effect of charged species using a quasielectrostatic approximation. Localized charges create an electric field, which in turn provides additional forcing in the mass and momentum equations. Our low Mach number formulation eliminates sound waves from the fully compressible formulation and leads to a more computationally efficient quasi-incompressible formulation. We demonstrate our ability to model saltwater (NaCl) solutions in both equilibrium and nonequilibrium settings. We show that our algorithm is second order in the deterministic setting and for length scales much greater than the Debye length gives results consistent with an electroneutral approximation. In the stochastic setting, our model captures the predicted dynamics of equilibrium and nonequilibrium fluctuations. We also identify and model an instability that appears when diffusive mixing occurs in the presence of an applied electric field.

  12. Offloading diabetic foot wounds using the scotchcast boot: a retrospective study.

    Science.gov (United States)

    Knowles, E Ann; Armstrong, David G; Hayat, Sajad A; Khawaja, Kashif I; Malik, Rayaz A; Boulton, Andrew J M

    2002-09-01

    A retrospective study was conducted to evaluate treatment outcomes associated with the treatment of diabetic foot ulcers using the Scotchcast boot. Data were extracted from the records of 180 patients with diabetes, 150 (83.3%) male, with a mean age of 55.3 +/- 10.9 years undergoing treatment for noninfected, non-ischemic neuropathic diabetic foot wounds at a university teaching hospital's tertiary care outpatient clinic. All patients who met the criteria were treated with the Scotchcast boot as the sole form of pressure relief. The average follow-up for each patient was 85.9 +/- 30.6 months (range 34.2 to 147.7 months). The mean time to healing for all patients was 130.5 +/- 106.7 days. Superficial (Grade 1) wounds healed significantly faster than deep (Grade 3) wounds (111.5 +/- 98.2 versus 180.8 +/- 138.8 days, P = 0.01) and 144 (80%) wounds healed during the follow-up period. Of the 36 (20%) that did not heal with Scotchcast boot therapy, 10 went on to more proximal amputation (5.6% of total population), two required surgical intervention to heal their wounds (0.6% of total population), one patient died with an unhealed wound (0.6% of total population), 23 patients (12.8% of total population) were lost to follow-up, and 47 (26%) died. Experience and the results of this and other studies suggest that this removable modality may be useful in outpatient care of deeper or complex wounds that require frequent inspection, but a device that ensures compliance may be the preferred treatment of superficial wounds.

  13. Genetic analysis of cold tolerance at the germination and booting stages in rice by association mapping.

    Directory of Open Access Journals (Sweden)

    Yinghua Pan

    Full Text Available Low temperature affects the rice plants at all stages of growth. It can cause severe seedling injury and male sterility resulting in severe yield losses. Using a mini core collection of 174 Chinese rice accessions and 273 SSR markers we investigated cold tolerance at the germination and booting stages, as well as the underlying genetic bases, by association mapping. Two distinct populations, corresponding to subspecies indica and japonica showed evident differences in cold tolerance and its genetic basis. Both subspecies were sensitive to cold stress at both growth stages. However, japonica was more tolerant than indica at all stages as measured by seedling survival and seed setting. There was a low correlation in cold tolerance between the germination and booting stages. Fifty one quantitative trait loci (QTLs for cold tolerance were dispersed across all 12 chromosomes; 22 detected at the germination stage and 33 at the booting stage. Eight QTLs were identified by at least two of four measures. About 46% of the QTLs represented new loci. The only QTL shared between indica and japonica for the same measure was qLTSSvR6-2 for SSvR. This implied a complicated mechanism of old tolerance between the two subspecies. According to the relative genotypic effect (RGE of each genotype for each QTL, we detected 18 positive genotypes and 21 negative genotypes in indica, and 19 positive genotypes and 24 negative genotypes in japonica. In general, the negative effects were much stronger than the positive effects in both subspecies. Markers for QTL with positive effects in one subspecies were shown to be effective for selection of cold tolerance in that subspecies, but not in the other subspecies. QTL with strong negative effects on cold tolerance should be avoided during MAS breeding so as to not cancel the effect of favorable QTL at other loci.

  14. Forge, Arquillian, Swarm and Spring Boot: All play and no effort makes Simon a productive boy

    CERN Document Server

    CERN. Geneva

    2017-01-01

    During this live coding session, Simon will shine some light on a range productivity tools that make software development a pleasure rather than a chore. Simon will live code 2 applications; a Java EE application, with JBoss Forge which uses JPA, Bean Validation, REST and Angular. We’ll test this application using Arquillian from within JBoss Forge. We’ll also show how a Java EE microservice can be developed in Forge and run using JBoss Swarm. The second application will be developed on Spring Boot and using JRebel we’ll rapidly develop and run a Spring application. Attendees will learn how to write code productively using tools designed for developers.

  15. Four Years of Real-Time GRB Followup by BOOTES-1B (2005–2008

    Directory of Open Access Journals (Sweden)

    Martin Jelínek

    2010-01-01

    Full Text Available Four years of BOOTES-1B GRB follow-up history are summarised for the first time in the form of a table. The successfully followed events are described case by case. Further, the data are used to show the GRB trigger rate in Spain on a per-year basis, resulting in an estimate of 18 triggers and about 51 hours of telescope time per year for real-time triggers. These numbers grow to about 22 triggers and 77 hours per year if we include also the GRBs observable within 2 hours after the trigger.

  16. A Practical Hardware-Assisted Approach to Customize Trusted Boot for Mobile Devices

    DEFF Research Database (Denmark)

    Gonzalez, Javier; Hölzl, Michael; Riedl, Peter

    2014-01-01

    is maintained with the components that have been loaded in the boot process for later audit. The first approach is often criticized for locking down devices, thus reducing users’ freedom to choose software. The second lacks the mechanisms to enforce any form of run-time verification. In this paper, we present...... their security requirements. This is a first step towards supporting usage control primitives for running applications. Our approach relies on off-the-shelf secure hardware that is available in a multitude of mobile devices: ARM TrustZone as a Trusted Execution Environment, and Secure Element as a tamper...

  17. Search for gamma ray burst quasi simultaneous optical emission with BOOTES-1

    Science.gov (United States)

    Castro Cerón, J. M.; Castro-Tirado, A. J.; Soldán, J.; Hudec, R.; Bernas, M.; Páta, P.; Mateo Sanguino, T. J.; de Ugarte Postigo, A.; Berná, J. Á; Nekola, M.; Gorosabel, J.; de la Morena, B. A.; Más-Hesse, J. M.; Giménez, Á.; Torres Riera, J.

    The Burst Observer and Optical Transient Exploring System experiment (BOOTES) has been designed to provide an automatic real time observing response to the detection of Gamma Ray Bursts (GRBs). It achieves such response by using wide field cameras attached to small robotic telescopes and imaging in the B,I and R bands. To date we have obtained images for about 50 events with the Wide Field Camera (WFC), starting, in several ocasions, 3 minutes after the burst commenced. One of the last searches resulted in the detection of an optical transient, candidate to be the optical counterpart of the GRB 000313, although such relation has not been established to absolute certainty yet.

  18. V404 Cyg optical spectroscopic evolution with BOOTES-2/TELMA (+COLORES)

    Science.gov (United States)

    Caballero-Garcia, M. D.; Castro-Tirado, A. J.; Jelinek, M.; Cunniffe, R.; Oates, S.; Galindo, P.; Tello, J. C.; et al.

    2015-07-01

    In light of the recent extreme outburst of V404 Cyg (GCN#17929) and follow-up by SWIFT, MAXI, INTEGRAL and many other ground-based observatories (ATELs from #7646 to #7763) the 0.6m TELMA robotic telescope at the BOOTES-2 astronomical station in Malaga (Spain), obtained 6 optical 4000-9000 A spectra using the COLORES spectrograph during the nights 2015-06-17 (22:35:11 UT), 2015-06-26 (03:45:13 UT), 2015-06-28 (23:54:16 UT) and 2015-06-29 (00:03:26, 00:12:33, 00:21:36 UT).

  19. Influence of new military athletic footwear on the kinetics and kinematics of running in relation to army boots.

    Science.gov (United States)

    Sinclair, Jonathan; Taylor, Paul J

    2014-10-01

    Musculoskeletal injuries in the lower extremities are common in military recruits. Army boots have frequently been cited as a potential mechanism behind these high injury rates. In response to this, the British Army introduced new footwear models, the PT-03 (cross-trainer) and PT1000 (running shoes), which are issued to each new recruit in an attempt to reduce the incidence of these injuries. The aim of the current investigation was to examine the kinetics and kinematic of the PT-03 and PT1000 footwear in relation to conventional army boots. Thirteen participants ran at 4.0 m·s in each footwear condition. Three-dimensional kinematics from the hip, knee, and ankle were measured using an 8-camera motion analysis system. In addition, simultaneous ground reaction forces were obtained. Kinetic parameters were obtained alongside joint kinematics and compared using repeated-measures analyses of variance. The kinetic analysis revealed that impact parameters were significantly greater when running in the army boot compared with the PT-03 and PT1000. The kinematic analysis indicated that, in comparison with the PT-03 and PT1000, running in army boots was associated with significantly greater eversion and tibial internal rotation. It was also found that when running in the PT-03 footwear, participants exhibited significantly greater hip adduction and knee abduction compared with the army boots and PT1000. The results of this study suggest that the army boots and PT-03 footwear are associated with kinetic and kinematic parameters that have been linked to the etiology of injury; thus, it is recommended that the PT1000 footwear be adopted for running exercises.

  20. Effects of wearing gumboots and leather lace-up boots on lower limb muscle activity when walking on simulated underground coal mine surfaces.

    Science.gov (United States)

    Dobson, Jessica A; Riddiford-Harland, Diane L; Steele, Julie R

    2015-07-01

    This study aimed to investigate the effects of wearing two standard underground coal mining work boots (a gumboot and a leather lace-up boot) on lower limb muscle activity when participants walked across simulated underground coal mining surfaces. Quadriceps (rectus femoris, vastus medialis, vastus lateralis) and hamstring (biceps femoris, semitendinosus) muscle activity were recorded as twenty male participants walked at a self-selected pace around a circuit while wearing each boot type. The circuit consisted of level, inclined and declined surfaces composed of rocky gravel and hard dirt. Walking in a leather lace-up boot, compared to a gumboot, resulted in increased vastus lateralis and increased biceps femoris muscle activity when walking on sloped surfaces. Increased muscle activity appears to be acting as a slip and/or trip prevention strategy in response to challenging surfaces and changing boot features.

  1. Detonation re-initiation mechanism following the Mach reflection of a quenched detonation

    CERN Document Server

    Bhattacharjee, Rohit; Maines, Geoffrey; Maley, Logan; Radulescu, Matei Ioan

    2012-01-01

    This experimental study addresses the re-initiation mechanism of detonation waves following the Mach reflection of a shock-flame complex. The detonation diffraction around a cylinder is used to reproducibly generate the shock-flame complex of interest. The experiments are performed in methane-oxygen. We use a novel experimental technique of coupling a two-in-line-spark flash system with a double-frame camera in order to obtain microsecond time resolution permitting accurate schlieren velocimetry. The first series of experiments compares the non-reactive sequence of shock reflections with the reflection over a rough wall under identical conditions. It was found that the hot reaction products generated along the rough wall are entrained by the wall jet into a large vortex structure behind the Mach stem. The second series of experiments performed in more sensitive mixtures addressed the sequence of events leading to the detonation establishment along the Mach and transverse waves. Following ignition and jet entr...

  2. Ernst Mach and the episode of the monocular depth sensations.

    Science.gov (United States)

    Banks, E C

    2001-01-01

    Although Ernst Mach is widely recognized in psychology for his discovery of the effects of lateral inhibition in the retina ("Mach Bands"), his contributions to the theory of depth perception are not as well known. Mach proposed that steady luminance gradients triggered sensations of depth. He also expanded on Ewald Hering's hypothesis of "monocular depth sensations," arguing that they were subject to the same principle of lateral inhibition as light sensations were. Even after Hermann von Helmholtz's attack on Hering in 1866, Mach continued to develop theories involving the monocular depth sensations, proposing an explanation of perspective drawings in which the mutually inhibiting depth sensations scaled to a mean depth. Mach also contemplated a theory of stereopsis in which monocular depth perception played the primary role. Copyright 2001 John Wiley & Sons, Inc.

  3. Design of a continuously variable Mach-number nozzle

    Institute of Scientific and Technical Information of China (English)

    郭善广; 王振国; 赵玉新

    2015-01-01

    A design method was developed to specify the profile of the continuously variable Mach-number nozzle for the supersonic wind tunnel. The controllable contour design technique was applied to obtaining the original nozzle profile, while other Mach- numbers were derived from the transformation of the original profile. A design scheme, covering a Mach-number range of 3.0Mach-number deviation at the nozzle exit. The present design method achieves the continuously variable Mach-number flow during a wind tunnel running.

  4. A new numerical solver for flows at various Mach numbers

    CERN Document Server

    Miczek, F; Edelmann, P V F

    2014-01-01

    Many problems in stellar astrophysics feature low Mach number flows. However, conventional compressible hydrodynamics schemes frequently used in the field have been developed for the transonic regime and exhibit excessive numerical dissipation for these flows. While schemes were proposed that solve hydrodynamics strictly in the low Mach regime and thus restrict their applicability, we aim at developing a scheme that correctly operates in a wide range of Mach numbers. Based on an analysis of the asymptotic behavior of the Euler equations in the low Mach limit we propose a novel scheme that is able to maintain a low Mach number flow setup while retaining all effects of compressibility. This is achieved by a suitable modification of the well-known Roe solver. Numerical tests demonstrate the capability of this new scheme to reproduce slow flow structures even in moderate numerical resolution. Our scheme provides a promising approach to a consistent multidimensional hydrodynamical treatment of astrophysical low Ma...

  5. Mach-like capillary-gravity wakes.

    Science.gov (United States)

    Moisy, Frédéric; Rabaud, Marc

    2014-08-01

    We determine experimentally the angle α of maximum wave amplitude in the far-field wake behind a vertical surface-piercing cylinder translated at constant velocity U for Bond numbers Bo(D)=D/λ(c) ranging between 0.1 and 4.2, where D is the cylinder diameter and λ(c) the capillary length. In all cases the wake angle is found to follow a Mach-like law at large velocity, α∼U(-1), but with different prefactors depending on the value of Bo(D). For small Bo(D) (large capillary effects), the wake angle approximately follows the law α≃c(g,min)/U, where c(g,min) is the minimum group velocity of capillary-gravity waves. For larger Bo(D) (weak capillary effects), we recover a law α∼√[gD]/U similar to that found for ship wakes at large velocity [Rabaud and Moisy, Phys. Rev. Lett. 110, 214503 (2013)]. Using the general property of dispersive waves that the characteristic wavelength of the wave packet emitted by a disturbance is of order of the disturbance size, we propose a simple model that describes the transition between these two Mach-like regimes as the Bond number is varied. We show that the new capillary law α≃c(g,min)/U originates from the presence of a capillary cusp angle (distinct from the usual gravity cusp angle), along which the energy radiated by the disturbance accumulates for Bond numbers of order of unity. This model, complemented by numerical simulations of the surface elevation induced by a moving Gaussian pressure disturbance, is in qualitative agreement with experimental measurements.

  6. The chemical evolution of the Bootes I ultra-faint dwarf galaxy

    CERN Document Server

    Frebel, Anna; Gilmore, Gerard; Wyse, Rosemary F G

    2016-01-01

    We present chemical abundance measurements of two metal-poor red giant stars in the ultra-faint dwarf galaxy Bootes I, based on Magellan/MIKE high-resolution spectra. For Boo I-980, with [Fe/H]=-3.1, we present the first elemental abundance measurements while Boo I-127, with [Fe/H]=-2.0, shows abundances in good agreement with previous measurements. Light and iron-peak element abundance ratios in the two Bootes I stars, as well as those of most other Boootes I members, collected from the literature, closely resemble those of regular metal-poor halo stars. Neutron-capture element abundances Sr and Ba are systematically lower than the main halo trend, and also show a significant abundance spread. Overall, this is similar to what has been found for other ultra-faint dwarf galaxies. We apply corrections to the carbon abundances (commensurate with stellar evolutionary status) of the entire sample and find 21% of stars to be carbon-enhanced metal-poor (CEMP) stars, compared to 13% without using the carbon correctio...

  7. Identifying Risk Factors of Boot Procurement: A Case Study of Stadium Australia

    Directory of Open Access Journals (Sweden)

    Marcus Jefferies

    2012-11-01

    Full Text Available Private sector input into the procurement of public works and services is continuing to increase. This has partly arisen out of a requirement for infrastructure development to be undertaken at a rate that maintains and allows growth. This has become a major challange for the construction industry that cannot be met by government alone. The emergence of Build-Own-Operate-Transfer (BOOT schemes as a response to this challange provides a means for developing the infrastructure of a country without directly impacting on the governments budgetary constraints. The concepts of BOOT are without doubt extremely complex arrangements, which bring to the construction sector risks not experienced previously. Many of the infrastructure partnerships between public and private sector in the pastare yet to provide evidence of successful completion, since few of the concession periods have expired. This paper provides an identified list of risk factors to a case study of Stadium Australia. The most significant risk associated with Stadium Australia include the bidding process, the high level of public scrutiny, post-Olympic Games facility revenue and the complicated nature of the consortium structure.  

  8. Identifying Risk Factors of Boot Procurement: A Case Study of Stadium Australia

    Directory of Open Access Journals (Sweden)

    Marcus Jefferies

    2012-11-01

    Full Text Available Private sector input into the procurement of public works and services is continuing to increase. This has partly arisen out of a requirement for infrastructure development to be undertaken at a rate that maintains and allows growth. This has become a major challange for the construction industry that cannot be met by government alone. The emergence of Build-Own-Operate-Transfer (BOOT schemes as a response to this challange provides a means for developing the infrastructure of a country without directly impacting on the governments budgetary constraints. The concepts of BOOT are without doubt extremely complex arrangements, which bring to the construction sector risks not experienced previously. Many of the infrastructure partnerships between public and private sector in the pastare yet to provide evidence of successful completion, since few of the concession periods have expired. This paper provides an identified list of risk factors to a case study of Stadium Australia. The most significant risk associated with Stadium Australia include the bidding process, the high level of public scrutiny, post-Olympic Games facility revenue and the complicated nature of the consortium structure.

  9. Microclimate in ski boots--temperature, relative humidity, and water absorption.

    Science.gov (United States)

    Hofer, Patrick; Hasler, Michael; Fauland, Gulnara; Bechtold, Thomas; Nachbauer, Werner

    2014-05-01

    Ski boot quality is determined by mechanical properties and comfort. Comfort is strongly affected by cold feet. The purpose of this study was to determine the microclimate in ski boots. Climate chamber tests with five male subjects and field tests with two male subjects were conducted. Temperature and relative humidity were measured using four sensors placed on the foot and one on the liner. Absorbed water in liners and socks was measured with a precision balance. The subjects gave subjective ratings for comfort. The toe sensor temperature dropped below 20 °C at an ambient temperature of 0 °C, -10 °C, and -20 °C. Relative humidity values at the foot were as high as 78% in the climate chamber and 93% in the field. Water absorption in socks and liners ranged from 4 to 10 g in the climate chamber and 19 to 45.5 g in the field. The results reveal the importance of keeping the feet and in particular the toes warm during skiing. One possible improvement may be to construct the liner so that sweat and melted snow are kept as far away as possible from the foot. Liner material with high water absorption capacity and hydrophobic socks were suggested to prevent wet feet.

  10. Variable stars in the newly discovered Milky Way satellite in Bootes

    CERN Document Server

    Dall'Ora, M; Kinemuchi, K; Ripepi, V; Marconi, M; Fabrizio, L D; Greco, C; Rodgers, C T; Kuehn, C; Smith, H A

    2006-01-01

    We present $V,I$ light curves for 12 variable stars identified in the newly discovered satellite of the Milky Way in the Bootes constellation (Belokurov et al. 2006).Our sample includes 11 RR Lyrae stars (5 first overtone, 5 fundamental mode and 1 double mode pulsator),and one long period variable close to the galaxy red giant branch tip. The RR Lyrae stars trace very well the average $V$ luminosity of the galaxy horizontal branch, leading to a true distance modulus for the galaxy of $\\mu_0$=19.11 $\\pm$ 0.08 mag for an assumed metal abundance of [Fe/H]=-2.5 (Monoz et al. 2006), and for $E(B-V)$=0.02 mag. Average periods are =0.69 d and =0.37 d for {\\it ab-} and {\\it c-} type RR Lyrae stars, respectively, making of Bootes the second pure Oosterhoff type II (OoII) dSph after Ursa Minor. The location of the double mode RR Lyrae (RRd) in the Petersen diagram is consistent with RRd stars in OoII clusters, and corresponds to an intrinsic luminosity of $log L/logL\\odot$=1.72 (for Z=10$^{-4}$ and M=0.80 M$\\odot$) acc...

  11. Integrated Mach-Zehnder interferometer for Bose-Einstein condensates.

    Science.gov (United States)

    Berrada, T; van Frank, S; Bücker, R; Schumm, T; Schaff, J-F; Schmiedmayer, J

    2013-01-01

    Particle-wave duality enables the construction of interferometers for matter waves, which complement optical interferometers in precision measurement devices. This requires the development of atom-optics analogues to beam splitters, phase shifters and recombiners. Integrating these elements into a single device has been a long-standing goal. Here we demonstrate a full Mach-Zehnder sequence with trapped Bose-Einstein condensates confined on an atom chip. Particle interactions in our Bose-Einstein condensate matter waves lead to a nonlinearity, absent in photon optics. We exploit it to generate a non-classical state having reduced number fluctuations inside the interferometer. Making use of spatially separated wave packets, a controlled phase shift is applied and read out by a non-adiabatic matter-wave recombiner. We demonstrate coherence times a factor of three beyond what is expected for coherent states, highlighting the potential of entanglement as a resource for metrology. Our results pave the way for integrated quantum-enhanced matter-wave sensors.

  12. A Randomized Evaluation of the Maryland Correctional Boot Camp for Adults: Effects on Offender Antisocial Attitudes and Cognitions

    Science.gov (United States)

    Mitchell, Ojmarrh; MacKenzie, Doris L.; Perez, Deanna M.

    2005-01-01

    This research addresses the question: Does the military atmosphere of a treatment-oriented boot camp lead to greater reductions in antisocial attitudes and cognitions than a standard correctional facility that is also treatment-oriented? A self-report measure of antisocial attitudes and cognitions was collected from 118 inmates randomly assigned…

  13. Mach band type lateral inhibition in different sense organs.

    Science.gov (United States)

    von Békésy, G

    1967-01-01

    Experiments were done on the skin with shearing forces, vibrations, and heat stimuli and on the tongue with taste stimuli to show that the well known Mach bands are not exclusively a visual phenomenon. On the contrary, it is not difficult to produce areas of a decreased sensation magnitude corresponding to the dark Mach bands in vision. It is shown on a geometrical model of nervous interaction that the appearance of Mach bands for certain patterns of stimulus distribution is correlated with nervous inhibition surrounding the area of sensation. This corroborates the earlier finding that surrounding every area transmitting sensation there is an area simultaneously transmitting inhibition.

  14. The Influence of Ernst Mach in the Teaching of Mechanics

    Science.gov (United States)

    Assis, Andre K. T.; Zylbersztajn, Arden

    We present Newton's main ideas for the formulation of classical mechanics as given in the Principia. Then we discuss Ernst Mach's criticisms of Newtonian mechanics as contained in his book The Science of Mechanics. We analyze the influence of Mach's ideas in the teaching of classical mechanics considering five representative textbooks: those of Kittel, Knight and Ruderman; Marion and Thornton; Symon; Feynman, Leighton and Sands; and Goldstein. We conclude that the influence of Mach's ideas has been very great, being incorporated in the textbooks, although not always with the deserved acknowledgment.

  15. Mach-Zehnder Phasing Sensor for Elts

    Science.gov (United States)

    Dohlen, Kjetil; Montoya-Martinez, Luzma

    Segmented mirror technology has been successfully applied to 10m class telescopes (Keck HET GTC) and its application to future extremely large telescopes (20m NG-CFHT 30m CELT 50m EURO50 100m OWL) is required. Extensive use of adaptive optics in these telescopes puts stringent specifications on wavefront error allowing typically of the order of lambda/20 to segmentation errors. Several phasing metrology schemes adaptable to these giant telescopes are under development. We investigate a novel technique based on the Mach-Zehnder interferometer with a spatial filter in one arm. Atmospheric turbulence is tolerated in this setup if the spatial filter has the size similar to that of the seeing disk. The resulting interference pattern only contains the high-frequency spatial information including information about the piston step height. We describe the theoretical analysis of this system and show simulated and experimatal results. Different error sources are analyzed in order to provide a preliminary idea of the merits of this technique compared with other phasing techniques.

  16. Emergent gravity of fractons: Mach's principle revisited

    Science.gov (United States)

    Pretko, Michael

    2017-07-01

    Recent work has established the existence of stable quantum phases of matter described by symmetric tensor gauge fields, which naturally couple to particles of restricted mobility, such as fractons. We focus on a minimal toy model of a rank 2 tensor gauge field, consisting of fractons coupled to an emergent graviton (massless spin-2 excitation). We show how to reconcile the immobility of fractons with the expected gravitational behavior of the model. First, we reformulate the fracton phenomenon in terms of an emergent center of mass quantum number, and we show how an effective attraction arises from the principles of locality and conservation of center of mass. This interaction between fractons is always attractive and can be recast in geometric language, with a geodesiclike formulation, thereby satisfying the expected properties of a gravitational force. This force will generically be short-ranged, but we discuss how the power-law behavior of Newtonian gravity can arise under certain conditions. We then show that, while an isolated fracton is immobile, fractons are endowed with finite inertia by the presence of a large-scale distribution of other fractons, in a concrete manifestation of Mach's principle. Our formalism provides suggestive hints that matter plays a fundamental role, not only in perturbing, but in creating the background space in which it propagates.

  17. Security Through Amnesia: A Software-Based Solution to the Cold Boot Attack on Disk Encryption

    CERN Document Server

    Simmons, Patrick

    2011-01-01

    Disk encryption has become an important security measure for a multitude of clients, including governments, corporations, activists, security-conscious professionals, and privacy-conscious individuals. Unfortunately, recent research has discovered an effective side channel attack against any disk mounted by a running machine\\cite{princetonattack}. This attack, known as the cold boot attack, is effective against any mounted volume using state-of-the-art disk encryption, is relatively simple to perform for an attacker with even rudimentary technical knowledge and training, and is applicable to exactly the scenario against which disk encryption is primarily supposed to defend: an adversary with physical access. To our knowledge, no effective software-based countermeasure to this attack supporting multiple encryption keys has yet been articulated in the literature. Moreover, since no proposed solution has been implemented in publicly available software, all general-purpose machines using disk encryption remain vu...

  18. VizieR Online Data Catalog: Spitzer/IRAC variability survey of Bootes field (Kozlowski+, 2016)

    Science.gov (United States)

    Kozlowski, S.; Kochanek, C. S.; Ashby, M. L. N.; Assef, R. J.; Brodwin, M.; Eisenhardt, P. R.; Jannuzi, B. T.; Stern, D.

    2016-04-01

    A detailed description of Spitzer Deep Wide-Field Survey (SDWFS) is presented in Ashby et al. (2009, see J/ApJ/716/530). The first epoch was taken on 2004 January 10-14 as the IRAC Shallow Survey (Eisenhardt et al. 2004ApJS..154...48E). Then, we added three more epochs on 2007 August 8-13, 2008 February 2-6, and 2008 March 6-10 as the SDWFS (Ashby et al. 2009, see J/ApJ/716/530; D. Stern PI, PID 40839). The new, fifth epoch was taken on 2014 April 23-29 as the Decadal IRAC Bootes Survey (DIBS; M.L.N. Ashby PI, PID 10088). The intervals between any two epochs span the range from 1 month to 10 years. (3 data files).

  19. Installation and first light of the BOOTES-IR near-IR camera

    Science.gov (United States)

    Cunniffe, R.; Castro-Tirado, A. J.; Kubánek, P.; Jelínek, M.; Vítek, S.; Gorosabel, J.; de Ugarte Postigo, A.; Riva, A.; Zerbi, F.; Claret, A.; Sánchez-Fernández, C.

    2008-07-01

    BIRCAM is a near-infrared (0.8-2.5um) cryogenic camera based on a 1Kx1K HgCdTe array. It was designed for - and is now mounted at - one of the Nasmyth foci of the fast-slewing 0.6 m BOOTES-IR telescope at the Sierra Nevada Observatory (OSN) in Spain. The primary science mission is prompt Gamma Ray-Burst afterglow research, with an implied demand for extremely time-efficient operation. We describe the challenges of installing a heavy camera on a small high-speed telescope, of integrating the dithering mechanism, the filterwheel, and the array itself into a high-efficiency instrument, the design of the software to meet the requirements.

  20. Improvement of Flow Quality in NAL Chofu Mach 10 Nozzle

    Science.gov (United States)

    Lacey, John; Inoue, Yasutoshi; Higashida, Akio; Inoue, Manabu; Ishizaka, Kouichi; Korte, John J.

    2002-01-01

    As a result of CFD analysis and remachining of the nozzle, the flow quality of the Mach 10 Hypersonic Wind Tunnel at NAL Chofu, Japan was improved. The subsequent test results validated the CFD analytical predictions by NASA and MHL.

  1. Mach's Principle selects 4 space-time dimensions

    CERN Document Server

    Altshuler, Boris L

    2012-01-01

    Bi-tensor kernel in integral form of Einstein equations realizing Mach's idea of non-existence of empty space-times is taken as an inverse of differential operator ("Mach operator") defined conventionally as a second variation of Einstein's gravity Action over contravariant components of metric tensor. The choice of transverse gauge condition used in this definition does not influence results of the paper since only transverse and traceless tensor modes written on different background space-times are studied. Presence of ghosts among modes of Mach operator invalidates the integral formulation of Einstein equations. And the demand of absence of these ghosts proves to be a selection rule for dimensionality of the background space-time. In particular Mach operator written on De Sitter background or on the background of so called "Einstein Universe" does not possess tensor ghosts only in 4-dimensions. The similar demand gives non-trivial formula for dimensionalities of subspaces of the Freund-Rubin background.

  2. Mach-Zehnder Fiber-Optic Links for ICF Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Miller, E. K., Hermann, H. W.

    2012-11-01

    This article describes the operation and evolution of Mach-Zehnder links for single-point detectors in inertial confinement fusion experimental facilities, based on the Gamma Reaction History (GRH) diagnostic at the National Ignition Facility.

  3. Improvement of Flow Quality in NAL Chofu Mach 10 Nozzle

    Science.gov (United States)

    Lacey, John; Inoue, Yasutoshi; Higashida, Akio; Inoue, Manabu; Ishizaka, Kouichi; Korte, John J.

    2002-01-01

    As a result of CFD analysis and remachining of the nozzle, the flow quality of the Mach 10 Hypersonic Wind Tunnel at NAL Chofu, Japan was improved. The subsequent test results validated the CFD analytical predictions by NASA and MHL.

  4. Numerical simulations of Mach stem formation via intersecting bow shocks

    Science.gov (United States)

    Hansen, E. C.; Frank, A.; Hartigan, P.; Yirak, K.

    2015-12-01

    Hubble Space Telescope observations show bright knots of Hα emission within outflowing young stellar jets. Velocity variations in the flow create secondary bow shocks that may intersect and lead to enhanced emission. When the bow shocks intersect at or above a certain critical angle, a planar shock called a Mach stem is formed. These shocks could produce brighter Hα emission since the incoming flow to the Mach stem is parallel to the shock normal. In this paper we report first results of a study using 2-D numerical simulations designed to explore Mach stem formation at the intersection of bow shocks formed by hypersonic "bullets" or "clumps". Our 2-D simulations show how the bow shock shapes and intersection angles change as the adiabatic index γ changes. We show that the formation or lack of a Mach stem in our simulations is consistent with the steady-state Mach stem formation theory. Our ultimate goal, which is part of an ongoing research effort, is to characterize the physical and observational consequences of bow shock intersections including the formation of Mach stems.

  5. Edge, cavity and aperture tones at very low Mach numbers

    Science.gov (United States)

    Howe, M. S.

    1997-01-01

    This paper discusses self-sustaining oscillations of high-Reynolds-number shear layers and jets incident on edges and corners at infinitesimal Mach number. These oscillations are frequently sources of narrow-band sound, and are usually attributed to the formation of discrete vortices whose interactions with the edge or corner produce impulsive pressures that lead to the formation of new vorticity and complete a feedback cycle of operation. Linearized analyses of these interactions are presented in which free shear layers are modelled by vortex sheets. Detailed results are given for shear flows over rectangular wall apertures and shallow cavities, and for the classical jet edge interaction. The operating stages of self-sustained oscillations are identified with poles in the upper half of the complex frequency plane of a certain impulse response function. It is argued that the real parts of these poles determine the Strouhal numbers of the operating stages observed experimentally for the real, nonlinear system. The response function coincides with the Rayleigh conductivity of the ‘window’ spanned by the shear flow for wall apertures and jet edge interactions, and to a frequency dependent drag coefficient for shallow wall cavities. When the interaction occurs in the neighbourhood of an acoustic resonator, exemplified by the flue organ pipe, the poles are augmented by a sequence of poles whose real parts are close to the resonance frequencies of the resonator, and the resonator can ‘speak’ at one of these frequencies (by extracting energy from the mean flow) provided the corresponding pole has positive imaginary part.

  6. Mach-Zehnder interferometer for movement monitoring

    Science.gov (United States)

    Vasinek, Vladimir; Cubik, Jakub; Kepak, Stanislav; Doricak, Jan; Latal, Jan; Koudelka, Petr

    2012-06-01

    Fiber optical interferometers belong to highly sensitive equipments that are able to measure slight changes like distortion of shape, temperature and electric field variation and etc. Their great advantage is that they are insensitive on ageing component, from which they are composed of. It is in virtue of herewith, that there are evaluated no changes in optical signal intensity but number interference fringes. To monitor the movement of persons, eventually to analyze the changes in state of motion we developed method based on analysis the dynamic changes in interferometric pattern. We have used Mach- Zehnder interferometer with conventional SM fibers excited with the DFB laser at wavelength of 1550 nm. It was terminated with optical receiver containing InGaAs PIN photodiode. Its output was brought into measuring card module that performs on FFT of the received interferometer signal. The signal rises with the composition of two waves passing through single interferometer arm. The optical fiber SMF 28e in one arm is referential; the second one is positioned on measuring slab at dimensions of 1x2m. A movement of persons around the slab was monitored, signal processed with FFT and frequency spectra were evaluated. They rose owing to dynamic changes of interferometric pattern. The results reflect that the individual subjects passing through slab embody characteristic frequency spectra, which are individual for particular persons. The scope of measuring frequencies proceeded from zero to 10 kHz. It was also displayed in experiments that the experimental subjects, who walked around the slab and at the same time they have had changed their state of motion (knee joint fixation), embodied characteristic changes in their frequency spectra. At experiments the stability of interferometric patterns was evaluated as from time aspects, so from the view of repeated identical experiments. Two kinds of balls (tennis and ping-pong) were used to plot the repeatability measurements and

  7. The BOOTES experiment in support of the Gran Telescopio Canarias (GTC) in the study of the high energy Universe

    Science.gov (United States)

    Castro Cerón, J. M.; de Ugarte Postigo, A.; García-Dabó, C. E.; Mateo Sanguino, T. J.; Páta, P.; Bernas, M.; Jelínek, M.; Hudec, R.; Berná, J. Á.; Gorosabel, J.; Más-Hesse, J. M.; Castro-Tirado, A. J.

    A GTC target of opportunity program (ToO) for gamma ray burst (GRB) afterglows will be a very powerful tool for studying the primitive Universe. Photometry and spectroscopy of GRBs are very suitable for tracing the star formation rate of the Universe at high redshifts (prompt optical and near-infrared observations with the GTC could detect GRBs to z <˜ 17; Castro-Tirado et al., this volume, p. 252; Gorosabel et al., this volume, p. 288). BOOTES (Burst Observer and Optical Transient Exploring System) can very efficiently support a ToO at the GTC through its robotized, extremely fast response capabilities. In this paper, we discuss the ongoing effort to finalize a real time, online, automatic data analysis system for BOOTES. Such a system will be able to provide early, reliable, and accurate GRB positions (confirmed by satellite) to trigger a GTC ToO.

  8. Nand Flash启动模式下的Uboot移植%Porting of Uboot for Booting from NAND Flash Mode

    Institute of Scientific and Technical Information of China (English)

    杨素秋

    2013-01-01

    BootLoader移植是嵌入式系统开发中的一个重要环节,而Uboot是一个支持多处理器多操作系统较为通用的BootLoader.分析了Uboot的启动过程,并对s3c2440A如何支持驱动代码在外部Nand Flash上的执行,以及在s3c2440A平台上如何实现Nand Flash启动模式下的Uboot移植进行了介绍.具体操作和编译在fedora9操作系统和arm-linux-gcc4.3.2交叉编译下完成.

  9. Lower Extremity Disorders among Men and Women in Army Basic Training and Effects of Two Types of Boots

    Science.gov (United States)

    1983-01-01

    27 R.R. Protzman and C.G. Griffis. Stress fractures in men and women undergoing military training. Journal of Bone and Joint Surgery , 59A, 825, 1977...was dropped on the rearfoot or the forefoot regions of the boots. de Moya found that the impact cushioning and energy absorption characteristics of the...fractures in men and women undergoing military training. Journal of Bone and Joint Surgery , 59A, 825, 1977. 28. K. A. Reinker ane S. A. Ozburne. A

  10. Designon P4080 Platform Secure Boot%P4080平台安全启动实现设计

    Institute of Scientific and Technical Information of China (English)

    郭庆; 赖韬; 余海

    2013-01-01

    This article describes the P4080 secure boot chain of trust creation and transfer process. With P4080 secure boot and credible structure, and as the digital signatures and authentication technology,the secureboot mechanism of two-level trust chain system from ISBC toUboot and from Uboot to Linux system is designed, and by modifying theboot image content and replacing the kernel image, the effectiveness of secureboot mechanisms is verified. With the equipment platform of this design, the tampering on boot code, configuration file, or operating system could be detected in the boot process, and thus the platform security of computing environments be protected.%介绍了P4080安全启动信任链建立和传递的过程;利用P4080安全启动和可信结构,采用数字签名及验证技术设计了从ISBC到Uboot、从Uboot到Linux系统的两级信任链系统安全启动机制,并采用修改启动映像内容和替换内核映像的方法验证了安全启动机制的有效性。采用该设计设备平台在启动过程中可检查到启动程序、配置文件、操作系统等程序文件是否被篡改过,从而保障平台计算环境的安全。

  11. Evaluating the impact of a Canadian national anatomy and radiology contouring boot camp for radiation oncology residents.

    Science.gov (United States)

    Jaswal, Jasbir; D'Souza, Leah; Johnson, Marjorie; Tay, KengYeow; Fung, Kevin; Nichols, Anthony; Landis, Mark; Leung, Eric; Kassam, Zahra; Willmore, Katherine; D'Souza, David; Sexton, Tracy; Palma, David A

    2015-03-15

    Radiation therapy treatment planning has advanced over the past 2 decades, with increased emphasis on 3-dimensional imaging for target and organ-at-risk (OAR) delineation. Recent studies suggest a need for improved resident instruction in this area. We developed and evaluated an intensive national educational course ("boot camp") designed to provide dedicated instruction in site-specific anatomy, radiology, and contouring using a multidisciplinary (MDT) approach. The anatomy and radiology contouring (ARC) boot camp was modeled after prior single-institution pilot studies and a needs-assessment survey. The boot camp incorporated joint lectures from radiation oncologists, anatomists, radiologists, and surgeons, with hands-on contouring instruction and small group interactive seminars using cadaveric prosections and correlative axial radiographs. Outcomes were evaluated using pretesting and posttesting, including anatomy/radiology multiple-choice questions (MCQ), timed contouring sessions (evaluated relative to a gold standard using Dice similarity metrics), and qualitative questions on satisfaction and perceived effectiveness. Analyses of pretest versus posttest scores were performed using nonparametric paired testing. Twenty-nine radiation oncology residents from 10 Canadian universities participated. As part of their current training, 29%, 75%, and 21% receive anatomy, radiology, and contouring instruction, respectively. On posttest scores, the MCQ knowledge scores improved significantly (pretest mean 60% vs posttest mean 80%, Pradiology in addition to enhancing their confidence and accuracy in contouring. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Early Career Boot Camp: a novel mechanism for enhancing early career development for psychologists in academic healthcare.

    Science.gov (United States)

    Foran-Tuller, Kelly; Robiner, William N; Breland-Noble, Alfiee; Otey-Scott, Stacie; Wryobeck, John; King, Cheryl; Sanders, Kathryn

    2012-03-01

    The purpose of this article is to describe a pilot mentoring program for Early Career Psychologists (ECPs) working in Academic Health Centers (AHCs) and synthesize the lessons learned to contribute to future ECP and AHC career development training programs. The authors describe an early career development model, named the Early Career Boot Camp. This intensive experience was conducted as a workshop meant to build a supportive network and to provide mentorship and survival tools for working in AHCs. Four major components were addressed: professional effectiveness, clinical supervision, strategic career planning, and academic research. Nineteen attendees who were currently less than 5 years post completion of doctoral graduate programs in psychology participated in the program. The majority of boot camp components were rated as good to excellent, with no component receiving below average ratings. Of the components offered within the boot camp, mentoring and research activities were rated the strongest, followed by educational activities, challenges in AHCS, and promotion and tenure. The article describes the purpose, development, implementation, and assessment of the program in detail in an effort to provide an established outline for future organizations to utilize when mentoring ECPs.

  13. A study of the Unna Boot compared with the elastic bandage in venous ulcers: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Alcione Matos de Abreu

    2015-08-01

    Full Text Available AbstractObjective: to analyze the process of tissue repair in patients with venous ulcers using inelastic compression therapy (the Unna Boot, in comparison with the use of the elastic bandage.Method: a controlled randomized clinical trial in which the patients (n=18 were allocated to two groups, those who used the Unna Boot (group B and those who used the elastic bandage (group A. The study's follow-up period was 13 weeks.Results: a significant reduction took place, at the level of 5%, in the area, in square centimeters, of the ulcers of group B (p<0.0001 throughout the treatment, and there was a tendency of group A for reduction in the area of the ulcer, in centimeters squared (p=0.06, only after the fifth week.Conclusion: the treatment with the Unna Boot presented better results in venous ulcers with areas over 10cm², and the elastic bandage with Petrolatum(r gauze in venous ulcers below 10cm². Brazilian Clinical Trials Register: Trial (req: 195 and WHO UTN U1111-1122-5489.

  14. Numerical Simulations of Mach Stem Formation via Intersecting Bow Shocks

    CERN Document Server

    Hansen, Edward C; Hartigan, Patrick

    2014-01-01

    Hubble Space Telescope observations show bright knots of H$\\alpha$ emission within outflowing young stellar jets. Velocity variations in the flow create secondary bow shocks that may intersect and lead to enhanced emission. When the bow shocks intersect at or above a certain critical angle, a planar shock called a Mach stem is formed. These shocks could produce brighter H$\\alpha$ emission since the incoming flow to the Mach stem is parallel to the shock normal. In this paper we report first results of a study using 2-D numerical simulations designed to explore Mach stem formation at the intersection of bow shocks formed by hypersonic "bullets" or "clumps". Our 2-D simulations show how the bow shock shapes and intersection angles change as the adiabatic index $\\gamma$ changes. We show that the formation or lack of a Mach stem in our simulations is consistent with the steady-state Mach stem formation theory. Our ultimate goal, which is part of an ongoing research effort, is to characterize the physical and obse...

  15. Study on Mach stems induced by interaction of planar shock waves on two intersecting wedges

    Institute of Scientific and Technical Information of China (English)

    Gaoxiang Xiang; Chun Wang; Honghui Teng; Yang Yang; Zonglin Jiang

    2016-01-01

    The properties of Mach stems in hypersonic corner flow induced by Mach interaction over 3D inter-secting wedges were studied theoretically and numerically. A new method called “spatial dimension reduction” was used to analyze theoretically the location and Mach num-ber behind Mach stems. By using this approach, the problem of 3D steady shock/shock interaction over 3D intersecting wedges was transformed into a 2D moving one on cross sec-tions, which can be solved by shock-polar theory and shock dynamics theory. The properties of Mach interaction over 3D intersecting wedges can be analyzed with the new method, including pressure, temperature, density in the vicinity of triple points, location, and Mach number behind Mach stems. Theoretical results were compared with numerical results, and good agreement was obtained. Also, the influence of Mach number and wedge angle on the properties of a 3D Mach stem was studied.

  16. Low Mach Number Fluctuating Hydrodynamics of Diffusively Mixing Fluids

    CERN Document Server

    Donev, A; Sun, Y; Fai, T; Garcia, A L; Bell, J B

    2012-01-01

    We formulate low Mach number fluctuating hydrodynamic equations appropriate for modeling diffusive mixing in isothermal mixtures of fluids with different density and transport coefficients. These equations eliminate the fast isentropic fluctuations in pressure associated with the propagation of sound waves by replacing the equation of state with a local thermodynamic constraint. We demonstrate that the low Mach number model preserves the spatio-temporal spectrum of the slower diffusive fluctuations. We develop a strictly conservative finite-volume spatial discretization of the low Mach number fluctuating equations in both two and three dimensions. We construct several explicit Runge-Kutta temporal integrators that strictly maintain the equation of state constraint. The resulting spatio-temporal discretization is second-order accurate deterministically and maintains fluctuation-dissipation balance in the linearized stochastic equations. We apply our algorithms to model the development of giant concentration fl...

  17. Mach-Zehnder recording systems for pulsed power diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Miller, E. K.; Abbott, R. Q.; McKenna, I.; Macrum, G.; Baker, D.; Tran, V.; Rodriguez, E.; Kaufman, M. I.; Tibbits, A.; Silbernagel, C. T.; Waltman, T. B. [National Security Technologies, LLC, Santa Barbara and Livermore, California 93111 (United States); National Security Technologies, LLC, Los Alamos, New Mexico 87544 (United States); and National Security Technologies, LLC, North Las Vegas, Nevada 89193 (United States); Herrmann, H. W.; Kim, Y. H.; Mack, J. M.; Young, C. S.; Caldwell, S. E.; Evans, S. C.; Sedillo, T. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Stoeffl, W.; Grafil, E. [Lawrence Livermore National Laboratory, Livermore, California (United States); and others

    2012-10-15

    Fiber-optic transmission and recording systems, based on Mach-Zehnder modulators, have been developed and installed at the National Ignition Facility (NIF), and are being developed for other pulsed-power facilities such as the Z accelerator at Sandia, with different requirements. We present the design and performance characteristics for the mature analog links, based on the system developed for the Gamma Reaction History diagnostic at the OMEGA laser and at NIF. For a single detector channel, two Mach-Zehnders are used to provide high dynamic range at the full recording bandwidth with no gaps in the coverage. We present laboratory and shot data to estimate upper limits on the radiation effects as they impact recorded data quality. Finally, we will assess the technology readiness level for mature and developing implementations of Mach-Zehnder links for these environments.

  18. Mach-Zehnder recording systems for pulsed power diagnostics.

    Science.gov (United States)

    Miller, E K; Abbott, R Q; McKenna, I; Macrum, G; Baker, D; Tran, V; Rodriguez, E; Kaufman, M I; Tibbits, A; Silbernagel, C T; Waltman, T B; Herrmann, H W; Kim, Y H; Mack, J M; Young, C S; Caldwell, S E; Evans, S C; Sedillo, T J; Stoeffl, W; Grafil, E; Liebman, J; Beeman, B; Watts, P; Carpenter, A; Horsfied, C J; Rubery, M S; Chandler, G A; Torres, J A; Smelser, R M

    2012-10-01

    Fiber-optic transmission and recording systems, based on Mach-Zehnder modulators, have been developed and installed at the National Ignition Facility (NIF), and are being developed for other pulsed-power facilities such as the Z accelerator at Sandia, with different requirements. We present the design and performance characteristics for the mature analog links, based on the system developed for the Gamma Reaction History diagnostic at the OMEGA laser and at NIF. For a single detector channel, two Mach-Zehnders are used to provide high dynamic range at the full recording bandwidth with no gaps in the coverage. We present laboratory and shot data to estimate upper limits on the radiation effects as they impact recorded data quality. Finally, we will assess the technology readiness level for mature and developing implementations of Mach-Zehnder links for these environments.

  19. Mach-Zehnder Recording Systems for Pulsed Power Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Miller, E K; McKenna, I; Macrum, G; Baker, D; Tran, V; Rodriguez, E; Kaufman, M I; Tibbits, A; Silbernagel, C T; Waltman, T B; Herrmann, H W; Kim, Y H; Mack, J M; Young, C S; Caldwell, S E; Evans, S C; Sedillo, T J; Stoeffl, W; Grafil, E; Liebman, J; Beeman, B; Watts, P; Carpenter, A; Horsfied, C J; Rubery, M S; Chandler, G A; Torres, J A

    2012-10-01

    Fiber-optic transmission and recording systems, based on Mach-Zehnder modulators, have been developed and installed at the National Ignition Facility (NIF), and are being developed for other pulsed-power facilities such as Z-R at Sandia, with different requirements. We present the design and performance characteristics for the mature analog links, based on the system developed for the Gamma Reaction History (GRH) diagnostic at OMEGA and NIF. For a single detector channel, two Mach-Zehnders are used to provide high dynamic range at the full recording bandwidth with no gaps in the coverage. We present laboratory and shot data to estimate upper limits on the radiation effects as they impact recorded data quality. Finally, we will assess the technology readiness level for mature and developing implementations of Mach-Zehnder links for these environments.

  20. Evaluating the Impact of a Canadian National Anatomy and Radiology Contouring Boot Camp for Radiation Oncology Residents

    Energy Technology Data Exchange (ETDEWEB)

    Jaswal, Jasbir [Department of Radiation Oncology, London Health Sciences Centre, London, Ontario (Canada); D' Souza, Leah; Johnson, Marjorie [Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, London, Ontario (Canada); Tay, KengYeow [Department of Diagnostic Radiology, London Health Sciences, London, Ontario (Canada); Fung, Kevin; Nichols, Anthony [Department of Otolaryngology, Head & Neck Surgery, Victoria Hospital, London, Ontario (Canada); Landis, Mark [Department of Diagnostic Radiology, London Health Sciences, London, Ontario (Canada); Leung, Eric [Department of Radiation Oncology, London Health Sciences Centre, London, Ontario (Canada); Kassam, Zahra [Department of Diagnostic Radiology, St. Joseph' s Health Care London, London, Ontario (Canada); Willmore, Katherine [Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, London, Ontario (Canada); D' Souza, David; Sexton, Tracy [Department of Radiation Oncology, London Health Sciences Centre, London, Ontario (Canada); Palma, David A., E-mail: david.palma@lhsc.on.ca [Department of Radiation Oncology, London Health Sciences Centre, London, Ontario (Canada)

    2015-03-15

    Background: Radiation therapy treatment planning has advanced over the past 2 decades, with increased emphasis on 3-dimensional imaging for target and organ-at-risk (OAR) delineation. Recent studies suggest a need for improved resident instruction in this area. We developed and evaluated an intensive national educational course (“boot camp”) designed to provide dedicated instruction in site-specific anatomy, radiology, and contouring using a multidisciplinary (MDT) approach. Methods: The anatomy and radiology contouring (ARC) boot camp was modeled after prior single-institution pilot studies and a needs-assessment survey. The boot camp incorporated joint lectures from radiation oncologists, anatomists, radiologists, and surgeons, with hands-on contouring instruction and small group interactive seminars using cadaveric prosections and correlative axial radiographs. Outcomes were evaluated using pretesting and posttesting, including anatomy/radiology multiple-choice questions (MCQ), timed contouring sessions (evaluated relative to a gold standard using Dice similarity metrics), and qualitative questions on satisfaction and perceived effectiveness. Analyses of pretest versus posttest scores were performed using nonparametric paired testing. Results: Twenty-nine radiation oncology residents from 10 Canadian universities participated. As part of their current training, 29%, 75%, and 21% receive anatomy, radiology, and contouring instruction, respectively. On posttest scores, the MCQ knowledge scores improved significantly (pretest mean 60% vs posttest mean 80%, P<.001). Across all contoured structures, there was a 0.20 median improvement in students' average Dice score (P<.001). For individual structures, significant Dice improvements occurred in 10 structures. Residents self-reported an improved ability to contour OARs and interpret radiographs in all anatomic sites, 92% of students found the MDT format effective for their learning, and 93% found the boot camp

  1. The Efficacy of Mammography Boot Camp to Improve the Performance of Radiologists

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Hye [Dept. of Radiology, Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Jun, Jae Kwan [National Cancer Control Institute, National Cancer Center, Goyang (Korea, Republic of); Jung, Seung Eun [Dept. of Radiology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of); Kim, You Me [Dept. of Radiology, Dankook University Hospital, Cheonan (Korea, Republic of); Choi, Nami [Dept. of Radiology, Konkuk University Medical Center, Seoul (Korea, Republic of)

    2014-10-15

    To evaluate the efficacy of a mammography boot camp (MBC) to improve radiologists' performance in interpreting mammograms in the National Cancer Screening Program (NCSP) in Korea. Between January and July of 2013, 141 radiologists were invited to a 3-day educational program composed of lectures and group practice readings using 250 digital mammography cases. The radiologists' performance in interpreting mammograms were evaluated using a pre- and post-camp test set of 25 cases validated prior to the camp by experienced breast radiologists. Factors affecting the radiologists' performance, including age, type of attending institution, and type of test set cases, were analyzed. The average scores of the pre- and post-camp tests were 56.0 ± 12.2 and 78.3 ± 9.2, respectively (p < 0.001). The post-camp test scores were higher than the pre-camp test scores for all age groups and all types of attending institutions (p < 0.001). The rate of incorrect answers in the post-camp test decreased compared to the pre-camp test for all suspicious cases, but not for negative cases (p > 0.05). The MBC improves radiologists' performance in interpreting mammograms irrespective of age and type of attending institution. Improved interpretation is observed for suspicious cases, but not for negative cases.

  2. Exploring boot camps for ‘gatekeeper’ service courses in mathematics

    Directory of Open Access Journals (Sweden)

    Anita Campbell

    2015-11-01

    Full Text Available Pressure to increase the throughput of university students in ethical ways has been a catalyst for innovations to improve learning and student success. Student dropout occurs mostly in the first year of study and poor performance is a major contributor to dropout even if the underlying reason for the poor performance is not academic under-preparedness. This article discusses the design and implementation of a mathematics tutored reassessment programme (TRP or ‘boot camp’ to improve the pass rate of students writing supplementary examinations for first year engineering mathematics. Interviews with students and tutors suggest that the TRP cultivated positive affective changes in students. A notable result from this case study was that students who qualified for a reassessment with marks in the range 40%–44% (and who would not normally have been granted a supplementary examination outperformed students qualifying with marks of 45%–49%, for whom attendance at the TRP was optional. Theoretical motivations for five principles guiding the design of the TRP are discussed.

  3. LOFAR 150-MHz observations of the Bo\\"otes field: Catalogue and Source Counts

    CERN Document Server

    Williams, W L; Röttgering, H J A; Best, P; Dijkema, T J; de Gasperin, F; Hardcastle, M J; Heald, G; Prandoni, I; Sabater, J; Shimwell, T W; Tasse, C; van Bemmel, I M; Brüggen, M; Brunetti, G; Conway, J E; Enßlin, T; Engels, D; Falcke, H; Ferrari, C; Haverkorn, M; Jackson, N; Jarvis, M J; Kapinska, A D; Mahony, E K; Miley, G K; Morabito, L K; Morganti, R; Orrú, E; Retana-Montenegro, E; Sridhar, S S; Toribio, M C; White, G J; Wise, M W; Zwart, J T L

    2016-01-01

    We present the first wide area (19 deg$^2$), deep ($\\approx120-150$ {\\mu}Jy beam$^{-1}$), high resolution ($5.6 \\times 7.4$ arcsec) LOFAR High Band Antenna image of the Bo\\"otes field made at 130-169 MHz. This image is at least an order of magnitude deeper and 3-5 times higher in angular resolution than previously achieved for this field at low frequencies. The observations and data reduction, which includes full direction-dependent calibration, are described here. We present a radio source catalogue containing 6276 sources detected over an area of $19$\\,deg$^2$, with a peak flux density threshold of $5\\sigma$. As the first thorough test of the facet calibration strategy, introduced by van Weeren et al., we investigate the flux and positional accuracy of the catalogue. We present differential source counts that reach an order of magnitude deeper in flux density than previously achieved at these low frequencies, and show flattening at 150 MHz flux densities below 10 mJy associated with the rise of the low flux...

  4. Mathematical and numerical aspects of low mach number flows

    Energy Technology Data Exchange (ETDEWEB)

    Schochet, St.; Bresch, D.; Grenier, E.; Alazard, T.; Gordner, A.; Sankaran, V.; Massot, M.; Sery, R.; Pebay, P.; Lunch, O.; Mazhorova, O.; Turkel, O.E.; Faille, I.; Danchin, R.; Allain, O.; Birken, P.; Lafitte, O.; Kloczko, T.; Frick, W.; Bui, T.; Dellacherie, S.; Klein, R.; Roe, Ph.; Accary, G.; Braack, M.; Picano, F.; Cadiou, A.; Dinescu, C.; Lesage, A.C.; Wesseling, P.; Heuveline, V.; Jobelin, M.; Weisman, C.; Merkle, C.

    2004-07-01

    Low Mach number flows represent a significant part of the various flows encountered in geophysics, industry or every day life. Paradoxically, the mathematical analysis of the equations governing these flows is difficult and on the practical side, the research of numerical algorithms valid for all flow speeds is continuing to be a challenge. However, in the last decade, both from the theoretical and the numerical sides, significant progresses were made in the understanding and analysis of the equations governing these flows. This conference intends to provide an up-to-date inventory of recent mathematical and numerical results in the analysis of these flows by bringing together both mathematicians and numericists active in this area. In the framework of the conference, a numerical workshop is organized which proposes to compute several challenging low Mach number flows: liquid flow around non-cavitating and cavitating NACA0015 hydrofoil, natural convection with large temperature differences, free convection, free surface flow, vessel pressurization. This document brings together the descriptions of the test cases of the numerical workshop and the abstracts of the conference papers: A 3D high order finite volume method for the prediction of near-critical fluid flows (G. ACCARY, I. RASPO, P. BONTOUX, B. ZAPPOLI); low Mach number limit of the non-isentropic Navier-Stokes equations (T. ALAZARD); simulation of cavitation rolls past a forward step with a bubble model (O. ALLAIN, N. BLASKA, C. LECA); flux preconditioning methods and fire events (P. BIRKEN, A. MEISTER); an adaptive finite element solver for compressible flows: application to heat-driven cavity benchmarks in 2D and 3D (M. BRAACK); comparison of various implicit, explicit, centered and upwind schemes for the simulation of compressed flows on moving mesh (A. CADIOU, M. BUFFAT, L. Le PENVEN, C. Le RIBAULT); low Mach number limit for viscous compressible flows (R. DANCHIN); some Properties of the low Mach number

  5. Mathematical and numerical aspects of low mach number flows

    Energy Technology Data Exchange (ETDEWEB)

    Schochet, St.; Bresch, D.; Grenier, E.; Alazard, T.; Gordner, A.; Sankaran, V.; Massot, M.; Sery, R.; Pebay, P.; Lunch, O.; Mazhorova, O.; Turkel, O.E.; Faille, I.; Danchin, R.; Allain, O.; Birken, P.; Lafitte, O.; Kloczko, T.; Frick, W.; Bui, T.; Dellacherie, S.; Klein, R.; Roe, Ph.; Accary, G.; Braack, M.; Picano, F.; Cadiou, A.; Dinescu, C.; Lesage, A.C.; Wesseling, P.; Heuveline, V.; Jobelin, M.; Weisman, C.; Merkle, C.

    2004-07-01

    Low Mach number flows represent a significant part of the various flows encountered in geophysics, industry or every day life. Paradoxically, the mathematical analysis of the equations governing these flows is difficult and on the practical side, the research of numerical algorithms valid for all flow speeds is continuing to be a challenge. However, in the last decade, both from the theoretical and the numerical sides, significant progresses were made in the understanding and analysis of the equations governing these flows. This conference intends to provide an up-to-date inventory of recent mathematical and numerical results in the analysis of these flows by bringing together both mathematicians and numericists active in this area. In the framework of the conference, a numerical workshop is organized which proposes to compute several challenging low Mach number flows: liquid flow around non-cavitating and cavitating NACA0015 hydrofoil, natural convection with large temperature differences, free convection, free surface flow, vessel pressurization. This document brings together the descriptions of the test cases of the numerical workshop and the abstracts of the conference papers: A 3D high order finite volume method for the prediction of near-critical fluid flows (G. ACCARY, I. RASPO, P. BONTOUX, B. ZAPPOLI); low Mach number limit of the non-isentropic Navier-Stokes equations (T. ALAZARD); simulation of cavitation rolls past a forward step with a bubble model (O. ALLAIN, N. BLASKA, C. LECA); flux preconditioning methods and fire events (P. BIRKEN, A. MEISTER); an adaptive finite element solver for compressible flows: application to heat-driven cavity benchmarks in 2D and 3D (M. BRAACK); comparison of various implicit, explicit, centered and upwind schemes for the simulation of compressed flows on moving mesh (A. CADIOU, M. BUFFAT, L. Le PENVEN, C. Le RIBAULT); low Mach number limit for viscous compressible flows (R. DANCHIN); some Properties of the low Mach number

  6. Quantum heat engines based on electronic Mach-Zehnder interferometers

    Science.gov (United States)

    Hofer, Patrick P.; Sothmann, Björn

    2015-05-01

    We theoretically investigate the thermoelectric properties of heat engines based on Mach-Zehnder interferometers. The energy dependence of the transmission amplitudes in such setups arises from a difference in the interferometer arm lengths. Any thermoelectric response is thus of purely quantum-mechanical origin. In addition to an experimentally established three-terminal setup, we also consider a two-terminal geometry as well as a four-terminal setup consisting of two interferometers. We find that Mach-Zehnder interferometers can be used as powerful and efficient heat engines which perform well under realistic conditions.

  7. A Device for Measuring Sonic Velocity and Compressor Mach Number

    Science.gov (United States)

    1948-07-01

    resonator (the only 4 NACA TN No. 1664 accurate measurement required) is measured, as shomn in figure 1, by means of a mercury manometer . The compressor Mach...tube vs not connected to the ccmpressor inlet until after calibration. The pressure in the device was measured by means of the mercury manometer . Fram

  8. The 172 ks Chandra Exposure of the LALA Bootes Field: X-Ray Source Catalog

    Science.gov (United States)

    Wang, J. X.; Malhotra, S.; Rhoads, J. E.; Brown, M. J. I.; Dey, A.; Heckman, T. M.; Jannuzi, B. T.; Norman, C. A.; Tiede, G. P.; Tozzi, P.

    2004-01-01

    We present an analysis of a deep, 172 ks Chandra observation of the Large Area Lyman Alpha survey (LALA) Bootes field, obtained with the Advanced CCD Imaging Spectrometer (ACIS-I) on board the Chandra X-Ray Observatory. This is one of the deepest Chandra images of the extragalactic sky; only the 2 Ms Chandra Deep Field North (CDF-N) and 1 Ms Chandra Deep Field South (CDF-S) are substantially deeper. In this paper we present the X-ray source catalog obtained from this image, along with an analysis of source counts and optical identifications. The X-ray image is composed of two individual observations obtained in 2002 and reaches 0.5-2.0 and 2.0-10.0 keV flux limits of 1.5×10-16 and 1.0×10-15 ergs cm-2 s-1, respectively, for point sources near the aim point. A total of 168 X-ray sources were detected: 160 in the 0.5-7.0 keV band, 132 in the 0.5-2.0 keV band, and 111 in the 2.0-7.0 keV band. The X-ray source counts were derived and compared with those from other Chandra deep surveys; the hard X-ray source density of the LALA Bootes field is 33% higher than that of CDF-S at the flux level of 2.0×10-15 ergs cm-2 s-1, confirming the field-to-field variances of the hard-band source counts reported by previous studies. The deep exposure resolves >~72% of the 2.0-10.0 keV X-ray background. Our primary optical data are R-band imaging from the NOAO Deep Wide-Field Survey (NDWFS), with a limiting magnitude of R=25.7 (Vega, 3 σ, and 4" diameter aperture). We have found optical counterparts for 152 of the 168 Chandra sources (90%); 144 of these are detected in the R-band image, and eight have optical counterparts in other bands (either BW, V, I, or z'). Among the R-band nondetected sources, not more than 11 of them can possibly be at z>5, based on the hardness ratios of their X-ray emission and nondetections in bluer bands (BW, V). The majority (~76%) of the X-ray sources are found to have log(fX/fR) within 0.0+/-1 these are believed to be AGNs. Most of the X

  9. Searching for intermediate groups of galaxies with Suzaku in Bootes field

    Science.gov (United States)

    Tawara, Yuzuru; Mitsuishi, Ikuyuki

    2016-07-01

    To investigate redshift evolution of groups of galaxies is significant also in terms of galaxy evolution. Recent observational studies show that an AGN fraction and a magnitude gap between the first and the second brightest group galaxies increase in group environments at lower redshifts (Oh et al. 2014 & Gozaliasl et al. 2014). Thus, comprehension for the evolution of the systems will bring us to hints on both morphological evolution of galaxies and galaxy-galaxy interactions. However, observational samples of groups of galaxies at higher redshifts are limited due to its low flux and surface brightness. Thus, we aimed at searching for new samples using both X-ray and optical data. To identify the group systems at higher redshifts, deep optical imaging and spectroscopic data are needed. Bootes field is one of the best regions for this purpose because there are up to 17 bands of data available per source from infrared, optical, UV, and X-ray (e.g., Kenter et al. 2005, Chung et al. 2014). XBootes survey was conducted in 2003 using Chandra (Murray et al. 2005) and X-ray extended sources were detected around intermediate optically-identified groups of galaxies even though Chandra could not reveal their origins due to poor photon statistics. Thus, we conducted X-ray follow-up observations using Suzaku which has low and stable background and thus is optimum for such low surface brightness sources for brightest 6 group candidates with redshifts of 0.15-0.42. Consequently, Suzaku detected excess emissions from all the targets in their images and spectral analysis reveals that 6 sources are originated from group- or poor-cluster-scale halos with temperatures, abundances and luminosities of 1.6-3.0 keV, conference, we will report on the details of our analysis and results using multiwavelength data such as radio, optical and X-ray to examine the AGN fractions and magnitude gaps in our samples and discuss the redshift evolution.

  10. THE ANALYSIS OF MACHINES FOR THE FOOTWEAR PULL ON BOOT TREE

    Directory of Open Access Journals (Sweden)

    I. Pascari

    2011-01-01

    Full Text Available The ways of manufacturing of footwear have undergone a long evolutionary way, beginning with the manual work and finishing with the automated. The first sewing machine that had come to help the manappeared in ХVIII century. The Industrial progress of development and of the equipment it is possible to divide conditionally into three stages: from 60 till 90th years where it is attempt the two-operational power engine; from 90 till 2000 two machines were applied to an inhaling; and the modern period when inhaling processallows using less machines. The new machines had new patented system that allows the operator to put the position for preparation of the top of footwear according to the design of model that is applied to each size of footwear. The system provides an automatic centering of a narrow site of footwear that by means of a followingbeam of light the operator could guarantee each time exact width of capture of a long edge in beam parts ofpreparation of top. In a similar way the system provides exact positioning of the sample in toe cap footwear parts. Except the equipment by the modern electronic devices, the new machines have fashionable design, in particular, the polished black panel and the automated tray for the footwear, covered with genuine leather. Theappointment of these machines is universal: on them it is possible to carry out process of an inhaling for various types of footwear (boots, low shoes, shoes, etc. both as daily socks as model sports. Thus the footwear can be various groups of people– man, female, and children.

  11. 工作靴内底特性检测%Testing Insoles Properties for Work Boots

    Institute of Scientific and Technical Information of China (English)

    Jana Durisova

    2006-01-01

    该文研究内底革的实用性,尤其是用于工作靴的内底.因为该类鞋用于条件恶劣的环境,要求穿着舒适,利于健康.重要的两方面是:环境卫生性能和关于明确的肌肉运动体系的物理性能.人们的脚每天频繁运动,容易失水且使表面硬化,如果鞋内底能解决此问题则是既耗费低又简单的方法.对各种材料的内底进行检测发现能承受最大撞击力的材料是硅内底和胶原填充内底.%This study is oriented to the insoles, especially the utility properties of insoles which were tested in single-purpose all-rubber work boots. This type of footwear demands comfort and good health promoting properties because it is used in a hard terrain and conditions. Two aspects are important: the environmental hygiene and physical demand concerning the musculature of the foot and of the whole kinetic system thereof.The loss of damping abilities of hard surfaces, on which people mostly move nowadays, is replaced so by the absorbing ability of footwear bottom parts especially insoles because this is the cheapest and easiest way how to fix the problem. Among the samples of the foot inserts tested, the best results, namely the ability of elimination in maximum the shocks when walking and the subsequent pressures, have been found with the silicone insoles and gel-filled insoles.

  12. Estimating sensitivity and specificity of a PCR for boot socks to detect Campylobacter in broiler primary production using Bayesian latent class analysis

    DEFF Research Database (Denmark)

    Matt, Monika; Nordentoft, Steen; Ian, Kopacka

    2016-01-01

    The present study compares three different assays for sample collection and detection of Campylobacter spp. in broiler flocks, based on (i) the collection of faecal samples from intestinal organs (caecum), (ii) individual faecal droppings collected from the bedding and (iii) faecal material...... collected by socks placed on the outside of a pair of boots (boot socks) and used for walking around in the flock. The two first methods are examined for Campylobacter using a culture method (ISO-10272-2:2006), while the boot socks are tested using PCR. The PCR-assay is a genus specific multiplex PCR...... samples were collected at slaughter.The results were evaluated in the absence of a gold standard using a Bayesian latent class model. Austrian results showed higher sensitivity for PCR detection in sock samples (0.98; Bayesian credible interval (BCI) [0.93-1]) than for culture of faecal droppings (0...

  13. Boot cAMP: educational outcomes after 4 successive years of preparatory simulation-based training at onset of internship.

    Science.gov (United States)

    Fernandez, Gladys L; Page, David W; Coe, Nicholas P; Lee, Patrick C; Patterson, Lisa A; Skylizard, Loki; St Louis, Myron; Amaral, Marisa H; Wait, Richard B; Seymour, Neal E

    2012-01-01

    Preparatory training for new trainees beginning residency has been used by a variety of programs across the country. To improve the clinical orientation process for our new postgraduate year (PGY)-1 residents, we developed an intensive preparatory training curriculum inclusive of cognitive and procedural skills, training activities considered essential for early PGY-1 clinical management. We define our surgical PGY-1 Boot Camp as preparatory simulation-based training implemented at the onset of internship for introduction of skills necessary for basic surgical patient problem assessment and management. This orientation process includes exposure to simulated patient care encounters and technical skills training essential to new resident education. We report educational results of 4 successive years of Boot Camp training. Results were analyzed to determine if performance evidenced at onset of training was predictive of later educational outcomes. Learners were PGY-1 residents, in both categorical and preliminary positions, at our medium-sized surgical residency program. Over a 4-year period, from July 2007 to July 2010, all 30 PGY-1 residents starting surgical residency at our institution underwent specific preparatory didactic and skills training over a 9-week period. This consisted of mandatory weekly 1-hour and 3-hour sessions in the Simulation Center, representing a 4-fold increase in time in simulation laboratory training compared with the remainder of the year. Training occurred in 8 procedural skills areas (instrument use, knot-tying, suturing, laparoscopic skills, airway management, cardiopulmonary resuscitation, central venous catheter, and chest tube insertion) and in simulated patient care (shock, surgical emergencies, and respiratory, cardiac, and trauma management) using a variety of high- and low-tech simulation platforms. Faculty and senior residents served as instructors. All educational activities were structured to include preparatory materials

  14. Novel Sampling Method for Assessing Human-Pathogen Interactions in the Natural Environment Using Boot Socks and Citizen Scientists, with Application to Campylobacter Seasonality.

    Science.gov (United States)

    Jones, Natalia R; Millman, Caroline; van der Es, Mike; Hukelova, Miroslava; Forbes, Ken J; Glover, Catherine; Haldenby, Sam; Hunter, Paul R; Jackson, Kathryn; O'Brien, Sarah J; Rigby, Dan; Strachan, Norval J C; Williams, Nicola; Lake, Iain R

    2017-07-15

    This paper introduces a novel method for sampling pathogens in natural environments. It uses fabric boot socks worn over walkers' shoes to allow the collection of composite samples over large areas. Wide-area sampling is better suited to studies focusing on human exposure to pathogens (e.g., recreational walking). This sampling method is implemented using a citizen science approach: groups of three walkers wearing boot socks undertook one of six routes, 40 times over 16 months in the North West (NW) and East Anglian (EA) regions of England. To validate this methodology, we report the successful implementation of this citizen science approach, the observation that Campylobacter bacteria were detected on 47% of boot socks, and the observation that multiple boot socks from individual walks produced consistent results. The findings indicate higher Campylobacter levels in the livestock-dominated NW than in EA (55.8% versus 38.6%). Seasonal differences in the presence of Campylobacter bacteria were found between the regions, with indications of winter peaks in both regions but a spring peak in the NW. The presence of Campylobacter bacteria on boot socks was negatively associated with ambient temperature (P = 0.011) and positively associated with precipitation (P method for sampling human-pathogen interactions using boot socks and citizen science techniques, which enable us to sample human-pathogen interactions that may occur through visits to natural environments. This contrasts with traditional environmental sampling, which is based on spot sampling techniques and does not sample human-pathogen interactions. Our methods are of practical value to scientists trying to understand the transmission of pathogens from the environment to people. Our findings provide insight into the risk of Campylobacter exposure from recreational visits and an understanding of seasonal differences in risk and the factors behind these patterns. We highlight the Campylobacter species

  15. Experimental Verification Of The Osculating Cones Method For Two Waverider Forebodies At Mach 4 and 6

    Science.gov (United States)

    Miller, Rolf W.; Argrow, Brian M.; Center, Kenneth B.; Brauckmann, Gregory J.; Rhode, Matthew N.

    1998-01-01

    The NASA Langley Research Center Unitary Plan Wind Tunnel and the 20-Inch Mach 6 Tunnel were used to test two osculating cones waverider models. The Mach-4 and Mach-6 shapes were generated using the interactive design tool WIPAR. WIPAR performance predictions are compared to the experimental results. Vapor screen results for the Mach-4 model at the on- design Mach number provide visual verification that the shock is attached along the entire leading edge, within the limits of observation. WIPAR predictions of pressure distributions and aerodynamic coefficients show general agreement with the corresponding experimental values.

  16. Low Mach Number Fluctuating Hydrodynamics of Binary Liquid Mixtures

    CERN Document Server

    Nonaka, A J; Bell, J B; Donev, A

    2014-01-01

    Continuing on our previous work [ArXiv:1212.2644], we develop semi-implicit numerical methods for solving low Mach number fluctuating hydrodynamic equations appropriate for modeling diffusive mixing in isothermal mixtures of fluids with different densities and transport coefficients. We treat viscous dissipation implicitly using a recently-developed variable-coefficient Stokes solver [ArXiv:1308.4605]. This allows us to increase the time step size significantly compared to the earlier explicit temporal integrator. For viscous-dominated flows, such as flows at small scales, we develop a scheme for integrating the overdamped limit of the low Mach equations, in which inertia vanishes and the fluid motion can be described by a steady Stokes equation. We also describe how to incorporate advanced higher-order Godunov advection schemes in the numerical method, allowing for the treatment of fluids with high Schmidt number including the vanishing mass diffusion coefficient limit. We incorporate thermal fluctuations in...

  17. Quantitative Global Heat Transfer in a Mach-6 Quiet Tunnel

    Science.gov (United States)

    Sullivan, John P.; Schneider, Steven P.; Liu, Tianshu; Rubal, Justin; Ward, Chris; Dussling, Joseph; Rice, Cody; Foley, Ryan; Cai, Zeimin; Wang, Bo; Woodiga, Sudesh

    2012-01-01

    This project developed quantitative methods for obtaining heat transfer from temperature sensitive paint (TSP) measurements in the Mach-6 quiet tunnel at Purdue, which is a Ludwieg tube with a downstream valve, moderately-short flow duration and low levels of heat transfer. Previous difficulties with inferring heat transfer from TSP in the Mach-6 quiet tunnel were traced to (1) the large transient heat transfer that occurs during the unusually long tunnel startup and shutdown, (2) the non-uniform thickness of the insulating coating, (3) inconsistencies and imperfections in the painting process and (4) the low levels of heat transfer observed on slender models at typical stagnation temperatures near 430K. Repeated measurements were conducted on 7 degree-half-angle sharp circular cones at zero angle of attack in order to evaluate the techniques, isolate the problems and identify solutions. An attempt at developing a two-color TSP method is also summarized.

  18. Interplay between Mach cone and radial expansion in jet events

    Science.gov (United States)

    Tachibana, Y.; Hirano, T.

    2016-12-01

    We study the hydrodynamic response to jet propagation in the expanding QGP and investigate how the particle spectra after the hydrodynamic evolution of the QGP reflect it. We perform simulations of the space-time evolution of the QGP in gamma-jet events by solving (3+1)-dimensional ideal hydrodynamic equations with source terms. Mach cone is induced by the jet energy deposition and pushes back the radial flow of the expanding background. Especially in the case when the jet passage is off-central one, the number of particles emitted in the direction of the push back decreases. This is the signal including the information about the formation of the Mach cone and the jet passage in the QGP fluid.

  19. Low Mach Number Fluctuating Hydrodynamics of Multispecies Liquid Mixtures

    CERN Document Server

    Donev, A; Bhattacharjee, A K; Garcia, A L; Bell, J B

    2014-01-01

    We develop a low Mach number formulation of the hydrodynamic equations describing transport of mass and momentum in a multispecies mixture of incompressible miscible liquids at specified temperature and pressure that generalizes our prior work on ideal mixtures of ideal gases and binary liquid mixtures. In this formulation we combine and extend a number of existing descriptions of multispecies transport available in the literature. The formulation applies to non-ideal mixtures of arbitrary number of species, without the need to single out a 'solvent' species, and includes contributions to the diffusive mass flux due to gradients of composition, temperature and pressure. Momentum transport and advective mass transport are handled using a low Mach number approach that eliminates fast sound waves (pressure fluctuations) from the full compressible system of equations and leads to a quasi-incompressible formulation. Thermal fluctuations are included in our fluctuating hydrodynamics description following the princi...

  20. Global versus Local -- Mach's Principle versus the Equivalence Principle

    CERN Document Server

    Singleton, Douglas

    2016-01-01

    The equivalence principle is the conceptual basis for general relativity. In contrast Mach's principle, although said to have been influential on Einstein in his formulation of general relativity, has not been shown to be central to the structure of general relativity. In this essay we suggest that the quantum effects of Hawking and Unruh radiation are a manifestation of a {\\it thermal} Mach's principle, where the local thermodynamic properties of the system are determined by the non-local structure of the quantum fields which determine the vacuum of a given spacetime. By comparing Hawking and Unruh temperatures for the same local acceleration we find a violation of the Einstein elevator version of the equivalence principle, which vanishes in the limit that the horizon is approached.

  1. A Solar System Test of Mach's Principle with Gravimetric Data

    CERN Document Server

    Unzicker, A; Fabian, Karl; Unzicker, Alexander

    2006-01-01

    We present a new test for a possible Mach-Sciama dependence of the Gravitational constant G. According to Ernst Mach (1838-1916), the gravitational interaction depends on the distribution of masses in the universe. A corresponding hypothesis of Sciama (1953) on the gravitational constant, $c^2/G = \\sum m_i/r_i$, can be tested since the elliptic earth orbit should then cause minute annual variations in G. The test is performed by analyzing the gravity signals of a network of superconducting gravimeters (SG) which reach a precision of $10^{-10} m/s^2$. After reducing the signal by modelling tidal, meteorologic and geophysical effects, no significant evidence for the above dependence is found.

  2. Quantum interference in an asymmetric Mach-Zehnder interferometer

    Science.gov (United States)

    Trenti, A.; Borghi, M.; Mancinelli, M.; Price, H. M.; Fontana, G.; Pavesi, L.

    2016-08-01

    A re-visitation of the well known free space Mach-Zehnder interferometer is reported here. The coexistence between one-photon and two-photons interference from collinear color entangled photon pairs is investigated. Thisarises from an arbitrarily small unbalance in the arm transmittance. The tuning of such asymmetry is reflected in dramatic changes in the coincidence detection, revealing beatings between one particle and two particle interference patterns. In particular, the role of the losses and of the intrinsic phase imperfectness of the lossy beamsplitter are explored in a single-port excited Mach-Zehnder interferometer. This configuration is especially useful for quantum optics on a chip, where the guiding geometry forces photons to travel in the same spatial mode.

  3. Spatial heterodyne spectrometer based on the Mach-Zehnder interferometer

    Science.gov (United States)

    Cai, Qisheng; Xiangli, Bin; Du, Shusong

    2015-11-01

    Spatial heterodyne spectroscopy (SHS) is a new kind of Fourier-transform spectroscopic technique capable of very high spectral resolution. In this paper, a spatial heterodyne spectrometer based on the Mach-Zehnder interferometer (MZ-SHS) is proposed. It is modified by replacing one mirror in the Mach-Zehnder interferometer with a diffraction grating. This technique retains many of the advantages of traditional SHS. Moreover, the spatial frequency of the interferogram is strictly linear with wavenumber. We describe the concept of the new MZ-SHS and elaborate the exact expression of the interferogram. Also, a design example and two kinds of imitated interferograms are presented in this paper. One is simulated in MATLAB and the other is generated in ZEMAX using ray tracing method. The retrieved spectra from these two interferograms show a good agreement with the theoretical results.

  4. Statistical error in particle simulations of low mach number flows

    Energy Technology Data Exchange (ETDEWEB)

    Hadjiconstantinou, N G; Garcia, A L

    2000-11-13

    We present predictions for the statistical error due to finite sampling in the presence of thermal fluctuations in molecular simulation algorithms. The expressions are derived using equilibrium statistical mechanics. The results show that the number of samples needed to adequately resolve the flowfield scales as the inverse square of the Mach number. Agreement of the theory with direct Monte Carlo simulations shows that the use of equilibrium theory is justified.

  5. QTLs conferring cold tolerance at the booting stage of rice using recombinant inbred lines from a japonica x indica cross.

    Science.gov (United States)

    Andaya, V C; Mackill, D J

    2003-04-01

    Low temperature stress is common for rice grown in temperate regions and at high elevations in the tropics. The most senstive stage to this stress is booting, about 11 days before heading. Japonica cultivars are known to be more tolerant than indicas. We constructed a genetic map using 191 recombinant inbred lines derived from a cross between a temperate japonica, M-202, and a tropical indica, IR50, in order to locate quantitative trait loci (QTLs) conferring cold tolerance. The map with a total length of 1,276.8 cM and an average density of one marker every 7.1 cM was developed from 181 loci produced by 175 microsatellite markers. Cold tolerance was measured as the degree of spikelet sterility of treated plants at a 12 degrees C temperature for 5 days in the growth chamber. QTLs on chromosomes 1, 2, 3, 5, 6, 7, 9 and 12 were identified to confer cold tolerance at the booting stage. The QTL contribution to the phenotypic variation ranged from 11 to 17%. The two QTLs with the highest contribution to variation, designated qCTB2a and qCTB3, were derived from the tolerant parent, M-202, each explaining approximately 17% of the phenotypic variance. Two of the eight QTLs for cold tolerance were contributed by IR50.

  6. Reproducibility of the spatio-temporal variables and the ground reaction forces walking with fire fighting boots

    Directory of Open Access Journals (Sweden)

    Jesús Cámara Tobalina

    2010-11-01

    Full Text Available AbstractThe aim of this study is to analyze the reproducibility of the spatio-temporal variables and the ground reaction forces (GRF when walking with fire fighting boots in comparison to walking with low calf shoes. Spatio-temporal parameters and the variables related to the three components of the GRF of 39 people were recorded under two different walking conditions. A T-test to contrast the difference between the coefficients of variation (CV in both conditions was used. The CV of the spatio-temporal variables (i.e velocity (V, condition I = 2.01%; condition II = 1.81%, of the vertical (i.e. contact force (FZA of the left foot, condition I = 2.54%; condition II = 2.73% and of the antero-posterior GRF (i.e. maximum force (FXMAX of the left foot, condition I = 4.47%; condition II = 4.59% was lower than 12.5%, suggesting that these variables could be used to analyze the influence of fire fighting boots on the gait. However, the low reproducibility showed by medium-lateral parameters does not allow to use them. Apart from the bipodal phase no differences were found between the two walking conditions. Key words: biomechanics, footwear, variability.

  7. A Brief Boot Camp for 4th-Year Medical Students Entering into Pediatric and Family Medicine Residencies

    Science.gov (United States)

    Adler, Mark; Mangold, Karen; Trainor, Jennifer

    2016-01-01

    The transition from medical student to intern is a challenging process characterized by a steep learning curve. Focused courses targeting skills necessary for success as a resident have increased self-perceived preparedness, confidence, and medical knowledge. Our aim was to create a brief educational intervention for 4th-year medical students entering pediatric, family practice, and medicine/pediatric residencies to target skills necessary for an internship. The curriculum used a combination of didactic presentations, small group discussions, role-playing, facilitated debriefing, and simulation-based education. Participants completed an objective structured clinical exam requiring synthesis and application of multiple boot camp elements before and after the elective. Participants completed anonymous surveys assessing self-perceived preparedness for an internship, overall and in regards to specific skills, before the elective and after the course. Participants were asked to provide feedback about the course. Using checklists to assess performance, students showed an improvement in performing infant lumbar punctures (47.2% vs 77.0%; p 4. A focused boot camp addressing key knowledge and skills required for pediatric-related residencies was well received and led to improved performance of targeted skills and increased self-reported preparedness in many targeted domains. PMID:27014522

  8. Simulation-based education: understanding the socio-cultural complexity of a surgical training 'boot camp'.

    Science.gov (United States)

    Cleland, Jennifer; Walker, Kenneth G; Gale, Michael; Nicol, Laura G

    2016-08-01

    The focus of simulation-based education (SBE) research has been limited to outcome and effectiveness studies. The effect of social and cultural influences on SBE is unclear and empirical work is lacking. Our objective in this study was to explore and understand the complexity of context and social factors at a surgical boot camp (BC). A rapid ethnographic study, employing the theoretical lenses of complexity and activity theory and Bourdieu's concept of 'capital', to better understand the socio-cultural influences acting upon, and during, two surgical BCs, and their implications for SBE. Over two 4-day BCs held in Scotland, UK, an observer and two preceptors conducted 81 hours of observations, 14 field interviews and 11 formal interviews with faculty members (n = 10, including the lead faculty member, session leaders and junior faculty members) and participants (n = 19 core surgical trainees and early-stage residents). Data collection and inductive analysis for emergent themes proceeded iteratively. This paper focuses on three analytical themes. First, the complexity of the surgical training system and wider health care education context, and how this influenced the development of the BC. Second, participants' views of the BC as a vehicle not just for learning skills but for gaining 'insider information' on how best to progress in surgical training. Finally, the explicit aim of faculty members to use the Scottish Surgical Bootcamp to welcome trainees and residents into the world of surgery, and how this occurred. To the best of our knowledge, this is the first empirical study of a surgical BC that takes a socio-cultural approach to exploring and understanding context, complexities, uncertainties and learning associated with one example of SBE. Our findings suggest that a BC is as much about social and cultural processes as it is about individual, cognitive and acquisitive learning. Acknowledging this explicitly will help those planning similar enterprises and

  9. Emergent physics on Mach's principle and the rotating vacuum

    CERN Document Server

    Jannes, G

    2015-01-01

    Mach's principle applied to rotation can be correct if one takes into account the rotation of the quantum vacuum together with the Universe. Whether one can detect the rotation of the vacuum or not depends on its properties. If the vacuum is fully relativistic at all scales, Mach's principle should work and one cannot distinguish the rotation: in the rotating Universe+vacuum, the co-rotating bucket will have a flat surface (not concave). However, if there are "quantum gravity" effects which violate Lorentz invariance at high energy, then the rotation will become observable. This is demonstrated by analogy in condensed-matter systems, which consist of two subsystems: superfluid background (analog of vacuum) and "relativistic" excitations (analog of matter). For the low-energy (long-wavelength) observer the rotation of the vacuum is not observable. In the rotating frame, the "relativistic" quasiparticles feel the background as a Minkowski vacuum, i.e. they do not feel the rotation. Mach's idea of the relativity...

  10. Hysteresis phenomenon of hypersonic inlet at high Mach number

    Science.gov (United States)

    Jiao, Xiaoliang; Chang, Juntao; Wang, Zhongqi; Yu, Daren

    2016-11-01

    When the hypersonic inlet works at a Mach number higher than the design value, the hypersonic inlet is started with a regular reflection of the external compression shock at the cowl, whereas a Mach reflection will result in the shock propagating forwards to cause a shock detachment at the cowl lip, which is called "local unstart of inlet". As there are two operation modes of hypersonic inlet at high Mach number, the mode transition may occur with the operation condition of hypersonic inlet changing. A cowl-angle-variation-induced hysteresis and a downstream-pressure-variation-induced hysteresis in the hypersonic inlet start↔local unstart transition are obtained by viscous numerical simulations in this paper. The interaction of the external compression shock and boundary layer on the cowl plays a key role in the hysteresis phenomenon. Affected by the transition of external compression shock reflection at the cowl and the transition between separated and attached flow on the cowl, a hysteresis exists in the hypersonic inlet start↔local unstart transition. The hysteresis makes the operation of a hypersonic inlet very difficult to control. In order to avoid hysteresis phenomenon and keep the hypersonic inlet operating in a started mode, the control route should never pass through the local unstarted boundary.

  11. Pilot Testing of a Sampling Methodology for Assessing Seed Attachment Propensity and Transport Rate in a Soil Matrix Carried on Boot Soles and Bike Tires

    Science.gov (United States)

    Hardiman, Nigel; Dietz, Kristina Charlotte; Bride, Ian; Passfield, Louis

    2017-01-01

    Land managers of natural areas are under pressure to balance demands for increased recreation access with protection of the natural resource. Unintended dispersal of seeds by visitors to natural areas has high potential for weedy plant invasions, with initial seed attachment an important step in the dispersal process. Although walking and mountain biking are popular nature-based recreation activities, there are few studies quantifying propensity for seed attachment and transport rate on boot soles and none for bike tires. Attachment and transport rate can potentially be affected by a wide range of factors for which field testing can be time-consuming and expensive. We pilot tested a sampling methodology for measuring seed attachment and transport rate in a soil matrix carried on boot soles and bike tires traversing a known quantity and density of a seed analog (beads) over different distances and soil conditions. We found % attachment rate on boot soles was much lower overall than previously reported, but that boot soles had a higher propensity for seed attachment than bike tires in almost all conditions. We believe our methodology offers a cost-effective option for researchers seeking to manipulate and test effects of different influencing factors on these two dispersal vectors.

  12. Self-Control, Gender, and Age: A Survival Analysis of Recidivism among Boot Camp Graduates in a 5-Year Follow-Up

    Science.gov (United States)

    Benda, Brent B.; Toombs, Nancy J.; Corwyn, Robert Flynn

    2005-01-01

    This study of 572 male and 120 female graduates of a boot camp investigates the potency of self-control as a predictor of recidivism in comparison to gender, age, and elements of life-course theory. It also examines whether the effects of self-control on recidivism are commensurate within the categories of gender. Recidivism is defined as a felony…

  13. Laat ons niet buiten de boot vallen, een onderzoek naar het maatschappelijk en sociaal functioneren van mensen met een IQ tussen de 80 en 90

    NARCIS (Netherlands)

    Borren, W.; Stellema, G.; Wijck, E.E.E. van; Bouma, J.

    2001-01-01

    Het vertrekpunt van het onderzoek "Laat ons niet buiten de boot vallen" is een gespreksnotitie van een overleg tussen het Stichting Maatschappelijk Werk Fryslan (AMW) en de Sociaal Pedagogische Dienst Friesland Ït buro Kingma" (auteurs Ate Prozee SPD en Marianne Bouma AMW). Deze notitie werd later g

  14. MHz-rate nitric oxide planar laser-induced fluorescence imaging in a Mach 10 hypersonic wind tunnel.

    Science.gov (United States)

    Jiang, Naibo; Webster, Matthew; Lempert, Walter R; Miller, Joseph D; Meyer, Terrence R; Ivey, Christopher B; Danehy, Paul M

    2011-02-01

    Nitric oxide planar laser-induced fluorescence (NO PLIF) imaging at repetition rates as high as 1 MHz is demonstrated in the NASA Langley 31 in. Mach 10 hypersonic wind tunnel. Approximately 200 time-correlated image sequences of between 10 and 20 individual frames were obtained over eight days of wind tunnel testing spanning two entries in March and September of 2009. The image sequences presented were obtained from the boundary layer of a 20° flat plate model, in which transition was induced using a variety of different shaped protuberances, including a cylinder and a triangle. The high-speed image sequences captured a variety of laminar and transitional flow phenomena, ranging from mostly laminar flow, typically at a lower Reynolds number and/or in the near wall region of the model, to highly transitional flow in which the temporal evolution and progression of characteristic streak instabilities and/or corkscrew-shaped vortices could be clearly identified.

  15. Treatment of chronic plantar ulcer of the diabetic foot using an irremovable windowed fibreglass cast boot: prospective study of 177 patients.

    Science.gov (United States)

    Ha Van, Georges; Michaux, Caroline; Parquet, Hugues; Bourron, Olivier; Pradat-Diehl, Pascale; Hartemann, Agnes

    2015-10-01

    The objective of this study was to evaluate the level of healing of chronic neuropathic plantar ulcers, using an irremovable windowed fibreglass cast boot, which is only opened after healing. A single-centre prospective study of a cohort of 177 diabetic patients with chronic neuropathic plantar ulcers was carried out. The duration of neuropathic plantar ulcers was 604 ± 808 days, with a mean surface area of 4.6 ± 6.5 cm(2) , a mean depth of 1.04 ± 1.08 cm and a mean volume of 5.9 ± 17.7 cm(3) . After a mean of 96 days of wearing a windowed fibreglass cast boot (min 9 days, max 664 days and median 68 days), the level of healing reached 83.6%, although 29 patients did not heal (16.4%). The compliance was at 95%. NPUs with bigger volumes (p = 0.037) and those located at the heels ( p = 0.004) had significantly lower healing levels. Twenty-one patients had moderate peripheral arterial disease (12%), and 24 patients were ostectomized for underlying osteomyelitis (14%), before inclusion. Moderate peripheral arterial disease (p = 0.970) or operated osteomyelitis (p = 0.128) did not modify the level of healing significantly, which were of 81% and 70.8%, respectively. Complications include 12 ulcers due to the windowed fibreglass cast boot (i.e. 7%) and two other ulcers being moderately infected, resulting in 2% of toe amputation, but there was no major amputation or phlebitis. The treatment of old and deep NPUs of the diabetic foot by wearing a windowed fibreglass cast boot without opening the boot prior to healing offers very high ulcer recovery levels. Windowed fibreglass cast boots were changed in only 26 cases (14.6%). In addition, compliance was excellent and of the order of 95%. Furthermore, moderate peripheral arterial disease or a recent ostectomy did not affect the efficacy of windowed fibreglass cast boot.

  16. Impinging Jet Resonant Modes at Mach 1.5

    CERN Document Server

    Davis, Timothy

    2013-01-01

    High speed impinging jets have been the focus of several studies owing to their practical application and resonance dominated flow-field. The current study focuses on the identification and visualization of the resonant modes at certain critical impingement heights for a Mach 1.5 normally impinging jet. These modes are associated with high amplitude, discrete peaks in the power spectra and can be identified as having either axisymmetric or azimuthal modes. Their visualization is accomplished through phase-locked Schlieren imaging and fast-response pressure sensitive paint (PC-PSP) applied to the ground plane.

  17. Low Mach number fluctuating hydrodynamics of multispecies liquid mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Donev, Aleksandar, E-mail: donev@courant.nyu.edu; Bhattacharjee, Amit Kumar [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States); Nonaka, Andy; Bell, John B. [Center for Computational Science and Engineering, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Garcia, Alejandro L. [Department of Physics and Astronomy, San Jose State University, San Jose, California 95192 (United States)

    2015-03-15

    We develop a low Mach number formulation of the hydrodynamic equations describing transport of mass and momentum in a multispecies mixture of incompressible miscible liquids at specified temperature and pressure, which generalizes our prior work on ideal mixtures of ideal gases [Balakrishnan et al., “Fluctuating hydrodynamics of multispecies nonreactive mixtures,” Phys. Rev. E 89 013017 (2014)] and binary liquid mixtures [Donev et al., “Low mach number fluctuating hydrodynamics of diffusively mixing fluids,” Commun. Appl. Math. Comput. Sci. 9(1), 47-105 (2014)]. In this formulation, we combine and extend a number of existing descriptions of multispecies transport available in the literature. The formulation applies to non-ideal mixtures of arbitrary number of species, without the need to single out a “solvent” species, and includes contributions to the diffusive mass flux due to gradients of composition, temperature, and pressure. Momentum transport and advective mass transport are handled using a low Mach number approach that eliminates fast sound waves (pressure fluctuations) from the full compressible system of equations and leads to a quasi-incompressible formulation. Thermal fluctuations are included in our fluctuating hydrodynamics description following the principles of nonequilibrium thermodynamics. We extend the semi-implicit staggered-grid finite-volume numerical method developed in our prior work on binary liquid mixtures [Nonaka et al., “Low mach number fluctuating hydrodynamics of binary liquid mixtures,” http://arxiv.org/abs/1410.2300 (2015)] and use it to study the development of giant nonequilibrium concentration fluctuations in a ternary mixture subjected to a steady concentration gradient. We also numerically study the development of diffusion-driven gravitational instabilities in a ternary mixture and compare our numerical results to recent experimental measurements [Carballido-Landeira et al., “Mixed-mode instability of a

  18. Temperature sensitivity of waveguide Mach-Zehnder interferometer

    OpenAIRE

    Sokolov, Viktor

    2013-01-01

    This thesis is part of a project that aims to develop a sensor for the detection of methane in the air and in water based on a waveguide Mach-Zehnder interferometer. The main application of this sensor is monitoring the environment and the ability to detect a leakage of methane. The development of a sensor includes analysis of operational conditions. In this project one of the greatest concerns is temperature. The temperature difference can reach several tens of degrees in the air, and severa...

  19. Quantum logic processor: Implementation with electronic Mach-Zehnder interferometer

    Science.gov (United States)

    Sarkar, Angik; Bhattacharyya, T. K.; Patwardhan, Ajay

    2006-05-01

    An approach for implementation of quantum logic in electronic Mach-Zehnder interferometer (MZI) has been described in this letter. All single qubit gates can be achieved by electron spin manipulation using Rashba spin-orbit coupling. Double qubit gates can also be implemented using the orbital degree of freedom of the electron. The MZI can be realized with intertwined ballistic nanowires. Spin injection and detection in the system can be done by a mesoscopic Stern-Gerlach apparatus. The system can be coupled in an array to form the quantum logic processor.

  20. On Mach's Principle and the "Special" Theory of Relativity

    CERN Document Server

    Ashura, Uzumaki

    2016-01-01

    First, we present a history of the school of thought that the Cosmic Microwave Background Radiation acts as an ether in language familiar to high school students in English-speaking countries. Then we illustrate the properties of this ether and of a hypothetical "test mass" using a brand new thought experiment. Finally, we recount some post-Einstein efforts at a mathematical formulation of Mach's principle and raise some questions about what implications it has for the locality of rotation and for quantum gravity. This paper does not prove Einstein wrong.

  1. Configuration of SoC FPGA, Booting of HPS and running Bare Metal Application from SD card.

    CERN Document Server

    Zahid Rasheed, Awais

    2016-01-01

    First, a hardware design is created using Qsys in Quartus 16.0. Creation of the hardware design consists of configuring Hard Processor System (HPS) inside FPGA and adding necessary hardware blocks to the design. After generating the Qsys design, it is then instantiated in top level module in Verilog or VHDL. After setting up all pin assignments and adding all necessary files in the design, project is compiled to have a complete hardware design. Second part comprises full software design in correspondence with the hardware design and booting the HPS from SD card. Software includes enabling the different bridges used by HPS to communicate with FPGA, configuring FPGA from HPS and embedded application itself. Finally, everything is added in the SD card to get a complete automatic bare metal application running on the host board without any configuration what so ever.

  2. The boot software of the control unit of the near infrared spectrograph of the Euclid space mission: technical specification

    Science.gov (United States)

    Gómez-Sáenz-de-Tejada, Jaime; Toledo-Moreo, Rafael; Colodro-Conde, Carlos; Pérez-Lizán, David; Fernández-Conde, Jesús; Sánchez-Prieto, Sebastián.

    2016-07-01

    The Near Infrared Spectrograph and Photometer (NISP) is one of the instruments on board the ESA EUCLID mission. The Boot Software (BSW) is in charge of initialization and communications after a reset occurs at hard- ware level. The Universidad Politecnica de Cartagena and Instituto de Astrofisica de Canarias are responsible of the Instrument Control Unit of the NISP (NI-ICU) in the Euclid Consortium. The NI-ICU BSW is developed by Universidad de Alcaĺa, and its main functions are: communication with the S/C for memory management, self-tests and start of a patchable Application Software (ASW). This paper presents the NI-ICU BSW status of definition and design at the end of the Technical Specification phase.

  3. The quantitative methods boot camp: teaching quantitative thinking and computing skills to graduate students in the life sciences.

    Science.gov (United States)

    Stefan, Melanie I; Gutlerner, Johanna L; Born, Richard T; Springer, Michael

    2015-04-01

    The past decade has seen a rapid increase in the ability of biologists to collect large amounts of data. It is therefore vital that research biologists acquire the necessary skills during their training to visualize, analyze, and interpret such data. To begin to meet this need, we have developed a "boot camp" in quantitative methods for biology graduate students at Harvard Medical School. The goal of this short, intensive course is to enable students to use computational tools to visualize and analyze data, to strengthen their computational thinking skills, and to simulate and thus extend their intuition about the behavior of complex biological systems. The boot camp teaches basic programming using biological examples from statistics, image processing, and data analysis. This integrative approach to teaching programming and quantitative reasoning motivates students' engagement by demonstrating the relevance of these skills to their work in life science laboratories. Students also have the opportunity to analyze their own data or explore a topic of interest in more detail. The class is taught with a mixture of short lectures, Socratic discussion, and in-class exercises. Students spend approximately 40% of their class time working through both short and long problems. A high instructor-to-student ratio allows students to get assistance or additional challenges when needed, thus enhancing the experience for students at all levels of mastery. Data collected from end-of-course surveys from the last five offerings of the course (between 2012 and 2014) show that students report high learning gains and feel that the course prepares them for solving quantitative and computational problems they will encounter in their research. We outline our course here which, together with the course materials freely available online under a Creative Commons License, should help to facilitate similar efforts by others.

  4. The quantitative methods boot camp: teaching quantitative thinking and computing skills to graduate students in the life sciences.

    Directory of Open Access Journals (Sweden)

    Melanie I Stefan

    2015-04-01

    Full Text Available The past decade has seen a rapid increase in the ability of biologists to collect large amounts of data. It is therefore vital that research biologists acquire the necessary skills during their training to visualize, analyze, and interpret such data. To begin to meet this need, we have developed a "boot camp" in quantitative methods for biology graduate students at Harvard Medical School. The goal of this short, intensive course is to enable students to use computational tools to visualize and analyze data, to strengthen their computational thinking skills, and to simulate and thus extend their intuition about the behavior of complex biological systems. The boot camp teaches basic programming using biological examples from statistics, image processing, and data analysis. This integrative approach to teaching programming and quantitative reasoning motivates students' engagement by demonstrating the relevance of these skills to their work in life science laboratories. Students also have the opportunity to analyze their own data or explore a topic of interest in more detail. The class is taught with a mixture of short lectures, Socratic discussion, and in-class exercises. Students spend approximately 40% of their class time working through both short and long problems. A high instructor-to-student ratio allows students to get assistance or additional challenges when needed, thus enhancing the experience for students at all levels of mastery. Data collected from end-of-course surveys from the last five offerings of the course (between 2012 and 2014 show that students report high learning gains and feel that the course prepares them for solving quantitative and computational problems they will encounter in their research. We outline our course here which, together with the course materials freely available online under a Creative Commons License, should help to facilitate similar efforts by others.

  5. DSMC Simulation of High Mach Number Taylor-Couette Flow

    Science.gov (United States)

    Pradhan, Sahadev, , Dr.

    2017-01-01

    The main focus of this work is to characterise the Taylor-Couette flow of an ideal gas between two coaxial cylinders at Mach number Ma = (U_w /√{ kbT_w / m }) in the range 0.01 Boltzmann constant. The cylindrical surfaces are specified as being diffusely reflecting with the thermal accommodation coefficient equal to one. In the present analysis of high Mach number compressible Taylor-Couette flow using DSMC method, wall slip in the temperature and the velocities are found to be significant. Slip occurs because the temperature/velocity of the molecules incident on the wall could be very different from that of the wall, even though the temperature/velocity of the reflected molecules is equal to that of the wall. Due to the high surface speed of the inner cylinder, significant heating of the gas is taking place. The gas temperature increases until the heat transfer to the surface equals the work done in moving the surface. The highest temperature is obtained near the moving surface of the inner cylinder at a radius of about (1.26 r_1).

  6. Cosmological constant implementing Mach principle in general relativity

    Science.gov (United States)

    Namavarian, Nadereh; Farhoudi, Mehrdad

    2016-10-01

    We consider the fact that noticing on the operational meaning of the physical concepts played an impetus role in the appearance of general relativity (GR). Thus, we have paid more attention to the operational definition of the gravitational coupling constant in this theory as a dimensional constant which is gained through an experiment. However, as all available experiments just provide the value of this constant locally, this coupling constant can operationally be meaningful only in a local area. Regarding this point, to obtain an extension of GR for the large scale, we replace it by a conformal invariant model and then, reduce this model to a theory for the cosmological scale via breaking down the conformal symmetry through singling out a specific conformal frame which is characterized by the large scale characteristics of the universe. Finally, we come to the same field equations that historically were proposed by Einstein for the cosmological scale (GR plus the cosmological constant) as the result of his endeavor for making GR consistent with the Mach principle. However, we declare that the obtained field equations in this alternative approach do not carry the problem of the field equations proposed by Einstein for being consistent with Mach's principle (i.e., the existence of de Sitter solution), and can also be considered compatible with this principle in the Sciama view.

  7. Derivation of the low Mach number diphasic system. Numerical simulation in mono-dimensional geometry; Derivation du systeme diphasique bas Mach. Simulation numerique en geometrie monodimensionnelle

    Energy Technology Data Exchange (ETDEWEB)

    Dellacherie, St

    2004-07-01

    This work deals with the derivation of a diphasic low Mach number model obtained through a Mach number asymptotic expansion applied to the compressible diphasic Navier Stokes system, expansion which filters out the acoustic waves. This approach is inspired from the work of Andrew Majda giving the equations of low Mach number combustion for thin flame and for perfect gases. When the equations of state verify some thermodynamic hypothesis, we show that the low Mach number diphasic system predicts in a good way the dilatation or the compression of a bubble and has equilibrium convergence properties. Then, we propose an entropic and convergent Lagrangian scheme in mono-dimensional geometry when the fluids are perfect gases and we propose a first approach in Eulerian variables where the interface between the two fluids is captured with a level set technique. (author)

  8. 3-D Wizardry: Design in Papier-Mache, Plaster, and Foam.

    Science.gov (United States)

    Wolfe, George

    Papier-mache, plaster, and foam are inexpensive and versatile media for 3-dimensional classroom and studio art experiences. They can be used equally well by elementary, high school, or college students. Each medium has its own characteristic. Papier-mache is pliable but dries into a hard, firm surface that can be waterproofed. Plaster can be…

  9. 3-D Wizardry: Design in Papier-Mache, Plaster, and Foam.

    Science.gov (United States)

    Wolfe, George

    Papier-mache, plaster, and foam are inexpensive and versatile media for 3-dimensional classroom and studio art experiences. They can be used equally well by elementary, high school, or college students. Each medium has its own characteristic. Papier-mache is pliable but dries into a hard, firm surface that can be waterproofed. Plaster can be…

  10. Fundamental and analytical studies of optical emission from the Mach disk extracted from an ICP

    Energy Technology Data Exchange (ETDEWEB)

    Luan, S.; Pang, H.; Houk, R.S. [Iowa State Univ., Ames, IA (United States)

    1994-12-31

    An inductively coupled plasma is extracted into a small quartz vacuum chamber (approximately 1 torr) through a sampling orifice in a copper disk. Optical emission from the Mach disk region is measured with a new type of echelle spectrometer with two segmented-array charge-coupled device detectors (SCD), the Optima 3000 from Perkin-Elmer. This detector provides excellent quantum efficiency throughout the UV-visible region, as well as low dark current and readout noises. The spectral background emitted by the Mach disk is very low. If analyte line intensities from the Mach disk can be enhanced, the combined ICP-Mach disk-Optima instrument should provide excellent detection limits for simultaneous multielement analysis. Axial profiles of the optical emission of various atom and ion lines are measured. Intensities of various lines are maximized at the Mach disk location. The relationship between the location of the Mach disk and the vacuum operating pressure is studied, using a cathetometer to measure small changes in the location of the Mach disk. The effects of aerosol gas flow rate on the intensities of various lines are also investigated. Finally, several schemes for boosting the intensity from the Mach disk will be presented.

  11. Low Mach number theory of freely cooling granular gases

    CERN Document Server

    Meerson, Baruch; Vilenkin, Arkady

    2007-01-01

    We use hydrodynamic equations to investigate the dynamics of a freely cooling dilute granular gas with nearly elastic particle collisions. We assume a narrow channel geometry and focus on the regime where the sound travel time through the system is much shorter than the typical cooling time of the gas. As a result, the pressure rapidly becomes almost homogeneous, while the Mach number is small. Eliminating the sound waves and employing Lagrangian coordinates, we reduce the full hydrodynamics to a single nonlinear/nonlocal equation of a reaction-diffusion type. This equation describes a broad class of flows and, in particular, can follow the development of strongly nonlinear states during clustering instability. Without heat diffusion, the reduced equation is exactly soluble and develops a finite-time density blowup with the same local features as those exhibited by the recently found family of exact solutions of the full set of ideal hydrodynamic equations (Fouxon et al. 2007). The heat diffusion, however, ar...

  12. The Variation of Slat Noise with Mach and Reynolds Numbers

    Science.gov (United States)

    Lockhard, David P.; Choudhari, Meelan M.

    2011-01-01

    The slat noise from the 30P30N high-lift system has been computed using a computational fluid dynamics code in conjunction with a Ffowcs Williams-Hawkings solver. By varying the Mach number from 0.13 to 0.25, the noise was found to vary roughly with the 5th power of the speed. Slight changes in the behavior with directivity angle could easily account for the different speed dependencies reported in the literature. Varying the Reynolds number from 1.4 to 2.4 million resulted in almost no differences, and primarily served to demonstrate the repeatability of the results. However, changing the underlying hybrid Reynolds-averaged-Navier-Stokes/Large-Eddy-Simulation turbulence model significantly altered the mean flow because of changes in the flap separation. However, the general trends observed in both the acoustics and near-field fluctuations were similar for both models.

  13. Density Measurement of Compact Toroid with Mach-Zehnder Interferometer

    Science.gov (United States)

    Laufman-Wollitzer, Lauren; Endrizzi, Doug; Brookhart, Matt; Flanagan, Ken; Forest, Cary

    2016-10-01

    Utilizing a magnetized coaxial plasma gun (MCPG) built by Tri Alpha Energy, a dense compact toroid (CT) is created and injected at high speed into the Wisconsin Plasma Astrophysics Laboratory (WiPAL) vessel. A modified Mach-Zehnder interferometer from the Line-Tied Reconnection Experiment (LTRX) provides an absolute measurement of electron density. The interferometer is located such that the beam intersects the plasma across the diameter of the MCPG drift region before the CT enters the vessel. This placement ensures that the measurement is taken before the CT expand. Results presented will be used to further analyze characteristics of the CT. Funding provided by DoE, NSF, and WISE Summer Research.

  14. Turbomachinery for Low-to-High Mach Number Flight

    Science.gov (United States)

    Tan, Choon S.; Shah, Parthiv N.

    2004-01-01

    The thrust capability of turbojet cycles is reduced at high flight Mach number (3+) by the increase in inlet stagnation temperature. The 'hot section' temperature limit imposed by materials technology sets the maximum heat addition and, hence, sets the maximum flight Mach number of the operating envelope. Compressor pre-cooling, either via a heat exchanger or mass-injection, has been suggested as a means to reduce compressor inlet temperature and increase mass flow capability, thereby increasing thrust. To date, however, no research has looked at compressor cooling (i.e., using a compressor both to perform work on the gas path air and extract heat from it simultaneously). We wish to assess the feasibility of this novel concept for use in low-to-high Mach number flight. The results to-date show that an axial compressor with cooling: (1) relieves choking in rear stages (hence opening up operability), (2) yields higher-pressure ratio and (3) yields higher efficiency for a given corrected speed and mass flow. The performance benefit is driven: (i) at the blade passage level, by a decrease in the total pressure reduction coefficient and an increase in the flow turning; and (ii) by the reduction in temperature that results in less work required for a given pressure ratio. The latter is a thermodynamic effect. As an example, calculations were performed for an eight-stage compressor with an adiabatic design pressure ratio of 5. By defining non-dimensional cooling as the percentage of compressor inlet stagnation enthalpy removed by a heat sink, the model shows that a non-dimensional cooling of percent in each blade row of the first two stages can increase the compressor pressure ratio by as much as 10-20 percent. Maximum corrected mass flow at a given corrected speed may increase by as much as 5 percent. In addition, efficiency may increase by as much as 5 points. A framework for characterizing and generating the performance map for a cooled compressor has been developed

  15. Structure optimization of polymeric Mach-Zehnder rib waveguide

    Institute of Scientific and Technical Information of China (English)

    LU Rong-guo; LiU Yong-zhi; LIAO Jin-kun; LIAO Yi-tao; HAN Wen-jie

    2007-01-01

    A systematic analysis of the polymeric Mach-Zehnder rib waveguide is presented based on the calculation and optimization. The simulation is carried out with the Effective Index Method (EIM) and two-dimensional (2-D)Finite Difference Beam Propagation Method (FD-BPM). The large refractive index step between the consecutive polymer layers is reduced by using EIM and thus the precision of the calculation is ensured. The important parameters of the waveguide such as Y-junction angle and the separation gap are discussed and their relationships with the optical power propagation and the loss characteristics are investigated in this paper. The total loss of the optimized structure is 0.258 dB.

  16. Vibration induced phase noise in Mach-Zehnder atom interferometers

    CERN Document Server

    Miffre, A; Büchner, M; Trénec, G; Vigué, J; Miffre, Alain; Jacquey, Marion; B\\"{u}chner, Matthias; Vigu\\'{e}, Jacques

    2006-01-01

    The high inertial sensitivity of atom interferometers has been used to build accelerometers and gyrometers but this sensitivity makes these interferometers very sensitive to the laboratory seismic noise. This seismic noise induces a phase noise which is large enough to reduce the fringe visibility in many cases. We develop here a model calculation of this phase noise in the case of Mach-Zehnder atom interferometers and we apply this model to our thermal lithium interferometer. We are thus able to explain the observed dependence of the fringe visibility with the diffraction order. The dynamical model developed in the present paper should be very useful to further reduce this phase noise in atom interferometers and this reduction should open the way to improved interferometers.

  17. Unification of Gravity and Electromagnetism I: Mach's Principle and Cosmology

    CERN Document Server

    Ghose, Partha

    2014-01-01

    The phenomenological consequences of unification of Einstein gravity and electromagnetism in an early phase of a Machian universe with a very small and uniform electrical charge density $\\rho_q$ are explored. A form of the Strong Equivalence Principle for unified electrogravity is first formulated, and it immediately leads to (i) the empirical Schuster-Blackett law relating the magnetic moments and angular momenta of neutral astronomical bodies, (ii) an analogous relation between the linear acceleration of neutral massive bodies and associated electric fields, (iii) gravitational lensing in excess of Einstein gravity, and, with the additional assumption of scaling, to (iv) the Wesson relation between the angular momentum and the square of the mass of astronomical bodies. Incorporation of Sciama's version of Mach's principle leads to a new post-Newtonian dynamics (in the weak field limit of gravity alone without electromagnetism) that predicts flat rotation curves of galaxies without the need of dark matter ha...

  18. Mach-Zehnder Interferometer Based on Coupled Dielectric Pillars

    Institute of Scientific and Technical Information of China (English)

    GAO Ding-Shan; HAO Ran; ZHOU Zhi-Ping

    2007-01-01

    We propose a Mach-Zehnder interferometer (MZI) based on coupled dielectric pillars. It is composed of single-row pillar coupled waveguide modulating arms and three-row pillar waveguide 3 dB couplers. The slow light property and transmission loss of the single-row pillar modulating arm are optimized by the plane wave expansion method. A short 3dB coupler is designed based on the modes transformation in three-row pillar waveguide. Finite difference time domain simulations prove the validity of this MZI and show that it has low insertion loss of<1.1 dB and high extinction ratio of>12 dB.

  19. DSMC simulations of leading edge flat-plate boundary layer flows at high Mach number

    Science.gov (United States)

    Pradhan, Sahadev, , Dr.

    2017-01-01

    The flow over a 2D leading-edge flat plate is studied at Mach number Ma = (Uinf /√{kBTinf / m }) in the range Boltzmann constant. The variation of streamwise velocity, temperature, number-density, and mean free path along the wall normal direction away from the plate surface is studied. The qualitative nature of the streamwise velocity at high Mach number is similar to those in the incompressible limit (parabolic profile). However, there are important differences. The amplitudes of the streamwise velocity increase as the Mach number increases and turned into a more flatter profile near the wall. There is significant velocity and temperature slip at the surface of the plate, and the slip increases as the Mach number is increased. It is interesting to note that for the highest Mach numbers considered here, the streamwise velocity at the wall exceeds the sound speed, and the flow is supersonic throughout the flow domain.

  20. Variation with Mach Number of Static and Total Pressures Through Various Screens

    Science.gov (United States)

    Adler, Alfred A

    1946-01-01

    Tests were conducted in the Langley 24-inch highspeed tunnel to ascertain the static-pressure and total-pressure losses through screens ranging in mesh from 3 to 12 wires per inch and in wire diameter from 0.023 to 0.041 inch. Data were obtained from a Mach number of approximately 0.20 up to the maximum (choking) Mach number obtainable for each screen. The results of this investigation indicate that the pressure losses increase with increasing Mach number until the choking Mach number, which can be computed, is reached. Since choking imposes a restriction on the mass rate of flow and maximum losses are incurred at this condition, great care must be taken in selecting the screen mesh and wire dimmeter for an installation so that the choking Mach number is

  1. A new magnetic sensor with Mach-Zehnder/Sagnac optical fiber interferometer

    Institute of Scientific and Technical Information of China (English)

    Shuguang LI; Xinwan LI; Xin WANG; Jianping CHEN

    2009-01-01

    This paper presents a new structure for magnetic sensor with Mach-Zehnder/Sagnac optical fiber interferometer. The magnetostrictive optical fiber sensor is placed in one of the two arms of the Mach-Zehnder interferometer, which can detect the optic phase shift by testing the length difference of the arm caused by environmental magnetic field. Because of forward and backward transmission in the arms, the Mach-Zehnder/ Sagnac optical fiber interferometer can deduce twice exactly of the phase shift proportional to the length difference as Mach-Zehnder interferometer. Theoretically, description of the Mach-Zehnder/Sagnac interferometer is given, and some main issues in the magnetic field sensor with optical fiber interferometer are demonstrated with experiments. The magnetic sensors are implemented using the proposed methods.

  2. [Thought Experiments of Economic Surplus: Science and Economy in Ernst Mach's Epistemology].

    Science.gov (United States)

    Wulz, Monika

    2015-03-01

    Thought Experiments of Economic Surplus: Science and Economy in Ernst Mach's Epistemology. Thought experiments are an important element in Ernst Mach's epistemology: They facilitate amplifying our knowledge by experimenting with thoughts; they thus exceed the empirical experience and suspend the quest for immediate utility. In an economical perspective, Mach suggested that thought experiments depended on the production of an economic surplus based on the division of labor relieving the struggle for survival of the individual. Thus, as frequently emphasized, in Mach's epistemology, not only the 'economy of thought' is an important feature; instead, also the socioeconomic conditions of science play a decisive role. The paper discusses the mental and social economic aspects of experimental thinking in Mach's epistemology and examines those within the contemporary evolutionary, physiological, and economic contexts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. The u-boot mutation identifies a Hedgehog-regulated myogenic switch for fiber-type diversification in the zebrafish embryo

    OpenAIRE

    2001-01-01

    Developmental programs that govern the embryonic diversification of distinct kinds of muscles in vertebrates remain obscure. For instance, the most widely recognized attribute of early diversity among skeletal myoblasts is their ability to differentiate exclusively into fibers with slow or fast contractile properties. However, we know little about the developmental basis and genetic regulation of this seminal event in vertebrate myogenesis. Here we show that in the zebrafish, the u-boot gene ...

  4. U-Boot在S3C2440上移植和设置%Porting and Setting Method of U-Boot on S3C2440 Platform

    Institute of Scientific and Technical Information of China (English)

    王之磊; 李临生

    2012-01-01

    BootLoader是嵌入式系统开发的重要环节,是操作系统和硬件平台联系的桥梁,对嵌入式系统的后继开发十分重要.简介了BootLoader U-Boot目录结构、工作流程及其移植的思路和引导内核的方法;给出了移植uboot-2010-03到ARM微处理器S3C2440上,所需操作环境的搭建、具体代码的修改、具体参数的设置、所需的操作命令及常见错误的处理方法等要点.最后将编译生成了U-Boot.bin文件下载到ARM微处理器S3C2440上,经过测试U-Boot可以达到设计的功能要求并能够稳定的运行而且通过对其正确的配置成功的引导了内核.

  5. Implementation of an intern boot camp curriculum to address clinical competencies under the new Accreditation Council for Graduate Medical Education supervision requirements and duty hour restrictions.

    Science.gov (United States)

    Krajewski, Aleksandra; Filippa, Dawn; Staff, Ilene; Singh, Rekha; Kirton, Orlando C

    2013-08-01

    Today's general surgery interns are faced with increased duty hour restrictions and stringent competency-based supervision milestone requirements (ie, from direct to indirect supervision). Working within these constraints, we instituted a unique 2-month intern curriculum (boot camp) incorporating knowledge-based, experiential, and practical components. To describe our curriculum and the effect on resident performance and teaching faculty and nursing staff perceptions. All interns underwent a 2-month (July and August 2011) boot camp curriculum consisting of two 2½-hour knowledge-based and procedural skills (SimMan) didactic sessions per week and completion of 25 core intensive introductory American College of Surgeons Fundamentals of Surgery web-based self-study modules, followed by a standardized patient clinical skills assessment. Integrated general surgery residency program at the University of Connecticut School of Medicine, Farmington. Postgraduate year 1 general surgery categorical and preliminary residents. We used several assessment tools, including an intern boot camp survey, clinical skills assessment scores, intern American Board of Surgeons In-Training Examination scores, and nursing staff and teaching faculty surveys of intern performance and aptitudes compared with the previous year's interns. Data were analyzed by independent group t test, χ2 tests of proportions, and Fisher exact test for small sample cross tables. In total, 84% (91 of 108) of intern respondents agreed or strongly agreed with the usefulness, relevance, and execution of the boot camp. Compared with the previous year's interns, the nursing staff agreed or strongly agreed that the cohort interns were better at patient assessment, collaboration, and effective communication and provided compassionate and respectful patient care. More than 40% (7 of 17) of surveyed teaching faculty agreed or strongly agreed that the cohort interns demonstrated better patient care and procedural skills

  6. XBootes: An X-Ray Survey of the NDWFS Bootes Field - Paper I Overview and Initial Results

    CERN Document Server

    Murray, S S; Forman, W R; Jones, C; Green, P J; Kochanek, C S; Vikhlinin, A; Fabricant, D; Fazio, G; Brand, K; Brown, M J I; Dey, A; Jannuzi, B T; Najita, J; McNamara, B; Shields, J; Rieke, M; Murray, Stephen S.; Kenter, Almus; Forman, William R.; Jones, Christine; Green, Paul J.; Kochanek, Christopher S.; Vikhlinin, Alexey; Fabricant, Daniel; Fazio, Giovani; Brand, Kate; Brown, Michael J. I.; Dey, Arjun; Jannuzi, Buell T.; Najita, Joan; Namara, Brian Mc; Shields, Joseph; Rieke, Marcia

    2005-01-01

    We obtained a 5 ksec deep Chandra X-ray Observatory ACIS-I map of the 9.3 square degree Bootes field of the NOAO Deep Wide-Field Survey. Here we describe the data acquisition and analysis strategies leading to a catalog of 4642 (3293) point sources with 2 or more (4 or more) counts, corresponding to a limiting flux of roughly 4(8)x10^{-15} erg cm^{-2}s^{-1} in the 0.5-7 keV band. These Chandra XBootes data are unique in that they consitute the widest contiguous X-ray field yet observed to such a faint flux limit. Because of the extraordinarily low background of the ACIS, we expect only 14% (0.7%) of the sources to be spurious. We also detected 43 extended sources in this survey. The distribution of the point sources among the 126 pointings (ACIS-I has a 16 x 16 arcminute field of view) is consistent with Poisson fluctuations about the mean of 36.8 sources per pointing. While a smoothed image of the point source distribution is clumpy, there is no statistically significant evidence of large scale filamentary s...

  7. Characteristics of Gas Exchange and Chlorophyll Fluorescence in Different Position Leaves at Booting Stage in Rice Plants

    Institute of Scientific and Technical Information of China (English)

    Mo Yi-wei; JIN Song-heng; WANG Zhong; WANG Pin-mei; QIAN Shan-qin; ZHAO Kai; GU Yun-jie; YANG Yi-qing; YAO Sheng; JIANG De-an

    2004-01-01

    To investigate the senescence of rice leaves at different positions at booting stage, gas exchange and chlorophyll fluorescence properties in leaves at different positions were examined by using six rice materials. The net rates of photosynthesis (Pn),stomatal conductance (gs), transpiration rate (E) and water use efficiency (WUE) decreased significantly with lowering of leaf positions,while intercellular CO2 concentration (Cj) had a little change, indicating that the decrease of photosynthetic rate was not resulted from the decrease of gs. The decrease of SPAD reading which had a close correlation with chlorophyll content was one of apparent reasons resulting in the decease of Pn. Further evidence by chlorophyll fluorescence showed that the photochemical efficiency of PS Ⅱ and its electron transport rate (ETR) decreased substantially with lowering of the leaf positions but the variable-to-maximum fluorescence ratio(Fv/Fm) and efficiency of energy conversion of open PS Ⅱ (Fv'/Fm') remained rather stable, suggesting that primary limitation of Pn was suppression of electron transport of PS Ⅰ, and probably associated with carbon assimilation.

  8. The Allen Telescope Array Pi GHz Sky Survey I. Survey Description and Static Catalog Results for the Bootes Field

    CERN Document Server

    Bower, Geoffrey C; Keating, Garrett; Whysong, David; Ackermann, Rob; Atkinson, Shannon; Backer, Don; Backus, Peter; Barott, Billy; Bauermeister, Amber; Blitz, Leo; Bock, Douglas; Bradford, Tucker; Cheng, Calvin; Cork, Chris; Davis, Mike; DeBoer, Dave; Dexter, Matt; Dreher, John; Engargiola, Greg; Fields, Ed; Fleming, Matt; Forster, R James; Gutierrez-Kraybill, Colby; Harp, G R; Heiles, Carl; Helfer, Tamara; Hull, Chat; Jordan, Jane; Jorgensen, Susanne; Kilsdonk, Tom; Law, Casey; van Leeuwen, Joeri; Lugten, John; MacMahon, Dave; McMahon, Peter; Milgrome, Oren; Pierson, Tom; Randall, Karen; Ross, John; Shostak, Seth; Siemion, Andrew; Smolek, Ken; Tarter, Jill; Thornton, Douglas; Urry, Lynn; Vitouchkine, Artyom; Wadefalk, Niklas; Weinreb, Sandy; Welch, Jack; Werthimer, Dan; Williams, Peter K G; Wright, Melvyn

    2010-01-01

    The Pi GHz Sky Survey (PiGSS) is a key project of the Allen Telescope Array. PiGSS is a 3.1 GHz survey of radio continuum emission in the extragalactic sky with an emphasis on synoptic observations that measure the static and time-variable properties of the sky. During the 2.5-year campaign, PiGSS will twice observe ~250,000 radio sources in the 10,000 deg^2 region of the sky with b > 30 deg to an rms sensitivity of ~1 mJy. Additionally, sub-regions of the sky will be observed multiple times to characterize variability on time scales of days to years. We present here observations of a 10 deg^2 region in the Bootes constellation overlapping the NOAO Deep Wide Field Survey field. The PiGSS image was constructed from 75 daily observations distributed over a 4-month period and has an rms flux density between 200 and 250 microJy. This represents a deeper image by a factor of 4 to 8 than we will achieve over the entire 10,000 deg^2. We provide flux densities, source sizes, and spectral indices for the 425 sources d...

  9. A UV Ultra-luminous Lyman Break Galaxy at Z=2.78 in NDWFS Bootes Field

    CERN Document Server

    Bian, Fuyan; Jiang, Linhua; Dey, Arjun; Green, Richard F; Maiolino, Roberto; Walter, Fabian; McGreer, Ian; Wang, Ran; Lin, Yen-Ting

    2012-01-01

    We present one of the most ultraviolet (UV) luminous Lyman Break Galaxies (LBGs) (J1432+3358) at z=2.78, discovered in the NOAO Deep Wide-Field Survey (NDWFS) Bootes field. The R-band magnitude of J1432+3358 is 22.29 AB, more than two magnitudes brighter than typical L* LBGs at this redshift. The deep z-band image reveals two components of J1432+3358 separated by 1.0" with flux ratio of 3:1. The high signal-to-noise ratio (S/N) rest-frame UV spectrum shows Lya emission line and interstellar medium absorption lines. The absence of NV and CIV emission lines, the non-detection in X-ray and radio wavelengths and mid-infrared (MIR) colors indicate no or weak active galactic nuclei (AGN) (<10%) in this galaxy. The galaxy shows broader line profile with the full width half maximum (FWHM) of about 1000 km/s and larger outflow velocity (~500 km/s) than those of typical z~3 LBGs. The physical properties are derived by fitting the spectral energy distribution (SED) with stellar synthesis models. The dust extinction, ...

  10. Multiobjective Design Optimization of Supersonic Jet Engine in Different Cruise Mach Numbers

    Science.gov (United States)

    Ogawa, Masamichi; Sato, Tetsuya; Kobayashi, Hiroaki; Taguchi, Hideyuki

    The aim of this paper is to apply a multi-objective optimization generic algorithm (MOGA) to the conceptual design of the hypersonic/supersonic vehicles with different cruise Mach number. The pre-cooled turbojet engine is employed as a propulsion system and some engine parameters such as the precooler size, compressor size, compression ratio and fuel type are varied in the analysis. The result shows that the optimum cruise Mach number is about 4 if hydrogen fuel is used. Methane fuel instead of hydrogen reduces the vehicle gross weight by 33% in case of the Mach 2 vehicle.

  11. Mach stem formation in reflection and focusing of weak shock acoustic pulses.

    Science.gov (United States)

    Karzova, Maria M; Khokhlova, Vera A; Salze, Edouard; Ollivier, Sébastien; Blanc-Benon, Philippe

    2015-06-01

    The aim of this study is to show the evidence of Mach stem formation for very weak shock waves with acoustic Mach numbers on the order of 10(-3) to 10(-2). Two representative cases are considered: reflection of shock pulses from a rigid surface and focusing of nonlinear acoustic beams. Reflection experiments are performed in air using spark-generated shock pulses. Shock fronts are visualized using a schlieren system. Both regular and irregular types of reflection are observed. Numerical simulations are performed to demonstrate the Mach stem formation in the focal region of periodic and pulsed nonlinear beams in water.

  12. Progress in the development of a Mach 5 quiet tunnel

    Science.gov (United States)

    Beckwith, I. E.; Andere, J. B.; Stainback, P. C.; Harvey, W. D.; Srokowski, A. J.

    1977-01-01

    Various techniques to control and reduce radiated noise and the application of these techniques to a 1/2-water Mach 5 quiet tunnel are reviewed. Measurements in a small scale nozzle have shown that the upstream part of the supersonic wall boundary layer could be maintained laminar up to Reynolds numbers of nearly 4 x 1 million based on the test region length upstream of the nozzle exit. Turbulent noise levels in this test region were then reduced by an order of magnitude. To maintain low noise levels at higher Reynolds numbers, laminar flow noise shields are required. Data are presented for shields that consist of small diameter rods alined nearly parallel to the entrance flow with small gaps between the rods for boundary layer suction. Analysis and data presented on the noise shielding and reflection characteristics of flat plates and a rod-wall test panel indicate that freestream turbulent noise can be reduced by 70 to 90 deg at high Reynolds numbers. Performance estimates for the 1/2-meter tunnel are based on these results.

  13. 3D shock-bubble interactions at Mach 3

    CERN Document Server

    Hejazialhosseini, Babak; Koumoutsakos, Petros

    2012-01-01

    We present a simulation for the interactions of shockwaves with light spherical density inhomogeneities. Euler equations for two-phase compressible flows are solved in a 3D uniform resolution finite volume based solver using 5th order WENO reconstructions of the primitive quantities, HLL-type numerical fluxes and 3rd order TVD time stepping scheme. In this study, a normal Mach 3 shockwave in air is directed at a helium bubble with an interface Atwood number of -0.76. We employ 4 billion cells on a supercomputing cluster and demonstrate the development of this flow until relatively late times. Shock passage compresses the bubble and deposits baroclinic vorticity on the interface. Initial distribution of the vorticity and compressions lead to the formation of an air jet, interface roll-ups and the formation of a long lasting vortical core, the white core. Compressed upstream of the bubble turns into a mixing zone and as the vortex ring distances from this mixing zone, a plume-shaped region is formed and sustain...

  14. Highly stable polarization independent Mach-Zehnder interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Mičuda, Michal, E-mail: micuda@optics.upol.cz; Doláková, Ester; Straka, Ivo; Miková, Martina; Dušek, Miloslav; Fiurášek, Jaromír; Ježek, Miroslav, E-mail: jezek@optics.upol.cz [Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 77146 Olomouc (Czech Republic)

    2014-08-15

    We experimentally demonstrate optical Mach-Zehnder interferometer utilizing displaced Sagnac configuration to enhance its phase stability. The interferometer with footprint of 27×40 cm offers individually accessible paths and shows phase deviation less than 0.4° during a 250 s long measurement. The phase drift, evaluated by means of Allan deviation, stays below 3° or 7 nm for 1.5 h without any active stabilization. The polarization insensitive design is verified by measuring interference visibility as a function of input polarization. For both interferometer's output ports and all tested polarization states the visibility stays above 93%. The discrepancy in visibility for horizontal and vertical polarization about 3.5% is caused mainly by undesired polarization dependence of splitting ratio of the beam splitter used. The presented interferometer device is suitable for quantum-information and other sensitive applications where active stabilization is complicated and common-mode interferometer is not an option as both the interferometer arms have to be accessible individually.

  15. Ultra-Abrupt Tapered Fiber Mach-Zehnder Interferometer Sensors

    Directory of Open Access Journals (Sweden)

    Lanying Zhou

    2011-05-01

    Full Text Available A fiber inline Mach-Zehnder interferometer (MZI consisting of ultra-abrupt fiber tapers was fabricated through a new fusion-splicing method. By fusion-splicing, the taper diameter-length ratio is around 1:1, which is much greater than those (1:10 made by stretching. The proposed fabrication method is very low cost, 1/20–1/50 of those of LPFG pair MZI sensors. The fabricated MZIs are applied to measure refractive index, temperature and rotation angle changes. The temperature sensitivity of the MZI at a length of 30 mm is 0.061 nm/°C from 30–350 °C. The proposed MZI is also used to measure rotation angles ranging from 0° to 0.55°; the sensitivity is 54.98 nm/°. The refractive index sensitivity is improved by 3–5 fold by fabricating an inline micro–trench on the fiber cladding using a femtosecond laser. Acetone vapor of 50 ppm in N2 is tested by the MZI sensor coated with MFI–type zeolite thin film. The proposed MZI sensors are capable of in situ detection in many areas of interest such as environmental management, industrial process control, and public health.

  16. Ultra-abrupt tapered fiber Mach-Zehnder interferometer sensors.

    Science.gov (United States)

    Li, Benye; Jiang, Lan; Wang, Sumei; Zhou, Lanying; Xiao, Hai; Tsai, Hai-Lung

    2011-01-01

    A fiber inline Mach-Zehnder interferometer (MZI) consisting of ultra-abrupt fiber tapers was fabricated through a new fusion-splicing method. By fusion-splicing, the taper diameter-length ratio is around 1:1, which is much greater than those (1:10) made by stretching. The proposed fabrication method is very low cost, 1/20-1/50 of those of LPFG pair MZI sensors. The fabricated MZIs are applied to measure refractive index, temperature and rotation angle changes. The temperature sensitivity of the MZI at a length of 30 mm is 0.061 nm/°C from 30-350 °C. The proposed MZI is also used to measure rotation angles ranging from 0° to 0.55°; the sensitivity is 54.98 nm/°. The refractive index sensitivity is improved by 3-5 fold by fabricating an inline micro-trench on the fiber cladding using a femtosecond laser. Acetone vapor of 50 ppm in N(2) is tested by the MZI sensor coated with MFI-type zeolite thin film. The proposed MZI sensors are capable of in situ detection in many areas of interest such as environmental management, industrial process control, and public health.

  17. Courant Number and Mach Number Insensitive CE/SE Euler Solvers

    Science.gov (United States)

    Chang, Sin-Chung

    2005-01-01

    It has been known that the space-time CE/SE method can be used to obtain ID, 2D, and 3D steady and unsteady flow solutions with Mach numbers ranging from 0.0028 to 10. However, it is also known that a CE/SE solution may become overly dissipative when the Mach number is very small. As an initial attempt to remedy this weakness, new 1D Courant number and Mach number insensitive CE/SE Euler solvers are developed using several key concepts underlying the recent successful development of Courant number insensitive CE/SE schemes. Numerical results indicate that the new solvers are capable of resolving crisply a contact discontinuity embedded in a flow with the maximum Mach number = 0.01.

  18. Turbulent mixing of a slightly supercritical Van der Waals fluid at Low-Mach number

    CERN Document Server

    Battista, Francesco; Casciola, Carlo Massimo

    2014-01-01

    Supercritical fluids near the critical point are characterized by liquid-like densities and gas-like transport properties. These features are purposely exploited in different contexts ranging from natural products extraction/fractionation to aerospace propulsion. Large part of studies concerns this last context, focusing on the dynamics of supercritical fluids at high Mach number where compressibility and thermodynamics strictly interact. Despite the widespread use also at low Mach number, the turbulent mixing properties of slightly supercritical fluids have still not investigated in detail in this regime. This topic is addressed here by dealing with Direct Numerical Simulations (DNS) of a coaxial jet of a slightly supercritical Van der Waals fluid. Since acoustic effects are irrelevant in the Low Mach number conditions found in many industrial applications, the numerical model is based on a suitable low-Mach number expansion of the governing equation. According to experimental observations, the weakly superc...

  19. Wavelength conversion based on cross-phase modulation in a semiconductor Mach-Zehnder modulator

    DEFF Research Database (Denmark)

    Liu, Fenghai; Zheng, Xueyan; Oxenløwe, Leif Katsuo

    2001-01-01

    Wavelength conversion based on cross-phase modulation in a reversely biased semiconductor Mach-Zehnder modulator is proposed and successfully demonstrated in a commercial device. The converted signals exhibit extinction ratio >13 dB and penalty......Wavelength conversion based on cross-phase modulation in a reversely biased semiconductor Mach-Zehnder modulator is proposed and successfully demonstrated in a commercial device. The converted signals exhibit extinction ratio >13 dB and penalty...

  20. Structural design and analysis of a Mach zero to five turbo-ramjet system

    Science.gov (United States)

    Spoth, Kevin A.; Moses, Paul L.

    1993-01-01

    The paper discusses the structural design and analysis of a Mach zero to five turbo-ramjet propulsion system for a Mach five waverider-derived cruise vehicle. The level of analysis detail necessary for a credible conceptual design is shown. The results of a finite-element failure mode sizing analysis for the engine primary structure is presented. The importance of engine/airframe integration is also discussed.

  1. Note: A high Mach number arc-driven shock tube for turbulence studies.

    Science.gov (United States)

    Titus, J B; Alexander, A B; Johnson, J A

    2013-04-01

    A high Mach arc-driven shock tube has been built at the Center for Plasma Science and Technology of Florida A&M University to study shock waves. A larger apparatus with higher voltage was built to study more stable shock waves and subsequent plasmas. Initial measurements of the apparatus conclude that the desired Mach numbers can be reached using only two-thirds the maximum possible energy that the circuit can provide.

  2. [Investigation of Empiricism. On Ernst Mach's Conception of the Thought Experiment].

    Science.gov (United States)

    Krauthausen, Karin

    2015-03-01

    Investigation of Empiricism. On Ernst Mach's Conception of the Thought Experiment. The paper argues that Ernst Mach's conception of the thought experiment from 1897/1905 holds a singular position in the lively discussions and repeated theorizations that have continued up to the present in relation to this procedure. Mach derives the thought experiment from scientific practice, and does not oppose it to the physical experiment, but, on the contrary, endows it with a robust relation to the facts. For Mach, the thought experiment is a reliable means of determining empiricism, and at the same time a real, because open and unbiased, experimenting. To shed light on this approach, the paper carries out a close reading of the relevant texts in Mach's body of writings (in their different stages of revision) and proceeds in three steps: first, Mach's processual understanding of science will be presented, which also characterizes his research and publication practice (I. 'Aperçu' and 'Sketch'. Science as Process and Projection); then in a second step the physiological and biological justification and valorization of memory and association will be examined with which Mach limits the relevance of categories such as consciousness and will (II. The Biology of Consciousness. Or The Polyp Colony); against this background, thirdly, the specific empiricism can be revealed that Mach inscribes into the thought experiment by on the one hand founding it in the memory and association, and on the other by tracing it back to geometry, which he deploys as an experimenting oriented to experience (III. Thinking and Experience. The Thought Experiment). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Mach Cutoff Analysis and Results from NASA's Farfield Investigation of No-Boom Thresholds

    Science.gov (United States)

    Cliatt, Larry J., II; Hill, Michael A.; Haering, Edward A., Jr.

    2016-01-01

    In support of the ongoing effort by the National Aeronautics and Space Administration (NASA) to bring supersonic commercial travel to the public, the NASA Armstrong Flight Research Center and the NASA Langley Research Center, in partnership with other industry organizations and academia, conducted a flight research experiment to analyze acoustic propagation in the Mach cutoff shadow zone. The effort was conducted in the fall of 2012 and named the Farfield Investigation of No-boom Thresholds (FaINT). The test helped to build a dataset that will go toward further understanding of the unique acoustic propagation characteristics below Mach cutoff altitude. FaINT was able to correlate sonic boom noise levels measured below cutoff altitude with precise airplane flight conditions, potentially increasing the accuracy over previous studies. A NASA F-18B airplane made supersonic passes such that its Mach cutoff caustic would be at varying distances above a linear 60-microphone, 7375-ft (2247.9 m) long array. A TG-14 motor glider equipped with a microphone on its wing-tip also attempted to capture the same sonic boom waves above ground, but below the Mach cutoff altitude. This paper identified an appropriate metric for sonic boom waveforms in the Mach cutoff shadow zone called Perceived Sound Exposure Level; derived an empirical relationship between Mach cutoff flight conditions and noise levels in the shadow zone; validated a safe cutoff altitude theory presented by previous studies; analyzed the sensitivity of flight below Mach cutoff to unsteady atmospheric conditions and realistic aircraft perturbations; and demonstrated the ability to record sonic boom measurements over 5000 ft (1524.0 m) above ground level, but below Mach cutoff altitude.

  4. Ten million and one penguins, or, lessons learned from booting millions of virtual machines on HPC systems.

    Energy Technology Data Exchange (ETDEWEB)

    Minnich, Ronald G.; Rudish, Donald W.

    2009-01-01

    In this paper we describe Megatux, a set of tools we are developing for rapid provisioning of millions of virtual machines and controlling and monitoring them, as well as what we've learned from booting one million Linux virtual machines on the Thunderbird (4660 nodes) and 550,000 Linux virtual machines on the Hyperion (1024 nodes) clusters. As might be expected, our tools use hierarchical structures. In contrast to existing HPC systems, our tools do not require perfect hardware; that all systems be booted at the same time; and static configuration files that define the role of each node. While we believe these tools will be useful for future HPC systems, we are using them today to construct botnets. Botnets have been in the news recently, as discoveries of their scale (millions of infected machines for even a single botnet) and their reach (global) and their impact on organizations (devastating in financial costs and time lost to recovery) have become more apparent. A distinguishing feature of botnets is their emergent behavior: fairly simple operational rule sets can result in behavior that cannot be predicted. In general, there is no reducible understanding of how a large network will behave ahead of 'running it'. 'Running it' means observing the actual network in operation or simulating/emulating it. Unfortunately, this behavior is only seen at scale, i.e. when at minimum 10s of thousands of machines are infected. To add to the problem, botnets typically change at least 11% of the machines they are using in any given week, and this changing population is an integral part of their behavior. The use of virtual machines to assist in the forensics of malware is not new to the cyber security world. Reverse engineering techniques often use virtual machines in combination with code debuggers. Nevertheless, this task largely remains a manual process to get past code obfuscation and is inherently slow. As part of our cyber security work at

  5. Structure of the magnetopause for low Mach number and strongly northward interplanetary magnetic field

    Science.gov (United States)

    Le, G.; Russell, C. T.; Gosling, J. T.

    1994-12-01

    We use International Sun-Earth Explorer (ISEE) magnetic field and plasma data to examine dayside magnetopause crossing under conditions of low Mach number and strongly northward interplanetary magnetic field (IMF). When the solar wind Mach number is low, the IMF stregth and magnetoseath field stregth are large, and we expect the effects of magnetic reconection to be the strongest. When the IMF is strongly northward, we find that the location of the magnetopause boundary layer is very stationary in the space, and we observe many features that are common for both typical and low Mach numbers. However, under low Mach number conditions, we have observed some features that would be expected for cusp reconnection. The boundary layer near the subsolar region contains heated magnetosheath plasma with little hot magnetospheric component that has clearly entered the magnetosphere elsewhere. At least some of the structures present in the boundary layer are impulsive. Inside the boundary layer there is also clear evidence of acceleratedflow from the cusp region for strongly northward IMF at low Mach number. Reconnection beyond the cusp can explain the observed field, plasma, and flow signatures. Therefore at low Mach number, reconection is important in the formation of the boundary layer for northward IMF.

  6. Revisiting Einstein's Happiest Thought: On Ernst Mach and the Early History of Relativity

    Science.gov (United States)

    Staley, Richard

    2016-03-01

    This paper argues we should distinguish three phases in the formation of relativity. The first involved relational approaches to perception, and physiological and geometrical space and time in the 1860s and 70s. The second concerned electrodynamics and mechanics (special relativity). The third concerned mechanics, gravitation, and physical and geometrical space and time. Mach's early work on the Doppler effect, together with studies of visual and motor perception linked physiology, physics and psychology, and offered new approaches to physiological space and time. These informed the critical conceptual attacks on Newtonian absolutes that Mach famously outlined in The Science of Mechanics. Subsequently Mach identified a growing group of ``relativists,'' and his critiques helped form a foundation for later work in electrodynamics (in which he did not participate). Revisiting Mach's early work will suggest he was still more important to the development of new approaches to inertia and gravitation than has been commonly appreciated. In addition to what Einstein later called ``Mach's principle,'' I will argue that a thought experiment on falling bodies in Mach's Science of Mechanics also provided a point of inspiration for the happy thought that led Einstein to the equivalence principle.

  7. Effect of hoof boots and toe-extension shoes on the forelimb kinetics of horses during walking.

    Science.gov (United States)

    Amitrano, Fernando N; Gutierrez-Nibeyro, Santiago D; Schaeffer, David J

    2016-05-01

    OBJECTIVE To determine and compare the effect of hoof boots (HBs) and shoes with a toe extension on stance duration, ground reaction force, and sole length in contact with the ground in nonlame horses during walking. ANIMALS 6 nonlame Standardbreds. PROCEDURES Force plate gait analyses of the forelimbs were performed while the horses were walking barefoot before manipulation of feet (baseline), while the horses were walking fitted with HBs, while the horses were walking shod with toe-extension shoes, and while the horses were walking barefoot after shoe removal. Horses underwent radiography of both forelimb feet to determine the sole length in contact with the ground when barefoot, wearing HBs, and shod with toe-extension shoes. Stance duration, ground reaction force, and sole length were compared among the various walking sessions. RESULTS Compared with baseline findings, stance duration increased significantly when horses were fitted with HBs (7%) or toe-extension shoes (5%). Peak forelimb ground reaction force was similar among walking sessions; however, time of braking force peak was significantly greater during the stance phase only when horses wore HBs. Also, the sole length in contact with the ground was significantly longer in horses fitted with HBs (14.3 cm) or shod with the toe-extension shoes (17.6 cm), compared with that for one of the barefoot hooves (12.7 cm). CONCLUSIONS AND CLINICAL RELEVANCE In nonlame horses, use of HBs prolonged the stance time and time of braking force peak, which is indicative of a slower deceleration phase during limb impact with the ground. Also, the use of HBs prolonged the deceleration phase of the stride and increased the sole length in contact with the ground.

  8. Interpreting performance of mammograms by radiology residents trained in breast imaging: Comparison with radiologists who attend mammography boot camp

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Hye [Dept. of Radiology, Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Kim, Sung Hun [Dept. of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of); An, Jin Kyung [Dept. of Radiology, Eulji General Hospital, Eulji University College of Medicine, Seoul (Korea, Republic of); Choi, Seon Hyeong [Dept. of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Suk Jung [Dept. of Radiology, Haeundae Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2014-12-15

    To compare the interpreting performance of mammograms between residents trained in breast imaging and radiologists who attended the mammography boot camp (MBC) suggesting directions for training in breast imaging. We compared the performance of 61 residents trained in breast imaging for more than 2 months at 21 institutions with that of 141 radiologists who attended MBC using the same test case series. We compared mean scores and rates of correct answers between the two groups and examined residents' mean scores varied by institution. Residents' mean score was 60.9 ± 12.2 and radiologists' mean scores were 56.0 ± 12.2 (p = 0.004) and 78.3 ± 9.2 (p < 0.001) before and after camp, respectively. Residents were superior to pre-camp radiologists in interpreting microcalcifications (70.5% vs. 56.4%; p < 0.001) and true-negative cases (71.8% vs. 59.2%; p < 0.001). They were inferior to post-camp radiologists in interpreting mass/asymmetry (56.7% vs. 86.6%; p < 0.001) and microcalcifications (70.5% vs. 90.3%; p < 0.001). The mean score of all institutions except one was 61.8 ± 9.4. Trained residents' interpreting performance of mammograms is superior to that of pre-camp radiologists but inferior to that of post-camp radiologists. Substantial training in interpreting mammograms during residency is suggested.

  9. Native American lithic procurement along the international border in the boot heel region of southwestern New Mexico

    Directory of Open Access Journals (Sweden)

    K. E. Zeigler

    2011-06-01

    Full Text Available Multidisciplinary field projects can be very useful to a more fundamental understanding of the world around us, though these projects are not as common as they should be. In particular, the combination of archeology and geology combines our understanding of human behavior and human use of the landscape with an intimate knowledge of geologic processes and the materials available for human use in order to gain a broader understanding of human-Earth interaction. Here we present data from a cross-disciplinary project that uses a common dataset, archeological artifacts, to explore the anthropological and geologic implications of useage patterns. Archeological excavations and surveys conducted by the Office of Contract Archeology in 2007 along the route of the proposed international border fence reveal patterns of use of geologic materials by Archaic, Formative and Protohistoric Native Americans in the Boot Heel of southwestern New Mexico. Thousands of artifacts were recorded in multiple sites from Guadalupe Pass in the southern Peloncillo Mountains to the Carrizalillo Hills west of Columbus. We identified the lithologies of artifacts, ranging from projectile points to groundstones, and then constructed material movement maps based on either known procurement sites ("quarries" or outcrops identified as the closest source to a given site for each lithology. Not unexpectedly, the majority of the rock types utilized by native peoples are local siliceous volcanic materials. However, several artifacts constructed from obsidian were transported into the region from northern Mexico and eastern Arizona, indicating long-distance travel and/or trade routes. We also examine useage pattern difference between Archaic, Formative and Protohistoric sites. Additionally, a dramatic change in distribution of sources for geologic materials occurs between one pre-Spanish site and one post-Spanish site that are adjacent to one another.

  10. Boots on the Ground: Science-Management Partnerships Facilitate Climate Change Adaptation in National Forests

    Science.gov (United States)

    Peterson, D. L.; Halofsky, J. E.

    2013-12-01

    Effective climate change engagement on public lands is characterized by (1) an enduring science-management partnership, (2) involvement of key stakeholders, (3) consideration of broad landscapes with multiple landowners, (4) science-based, peer-reviewed assessments of sensitivity of natural resources to climate change, (5) adaptation strategies and tactics developed by resource managers, and (6) leadership and a workforce motivated to implement climate-smart practices in resource planning and project management. Using this sequence of steps, the U.S. Forest Service, in collaboration with other agencies and universities, has developed climate change vulnerability assessments and adaptation plans for national forests and other lands. Although implementation (step 6) has been slow in some cases, the success of this process has been documented in 25 national forests and is now being accelerated across the National Forest System (155 national forests). Although hundreds of meetings, strategies, plans, and panels have focused on climate change adaptation over the past decade, only direct engagement between scientists and resource managers (less planning, more doing) has resulted in substantive outcomes.

  11. Study of the functinal characteristics and of the boot use by military policeman and its influence in the performance in the activity of patrol

    Directory of Open Access Journals (Sweden)

    Ana Claudia Vieira Martins

    2005-06-01

    Full Text Available This descriptive diagnosis study had the objective to evaluate the functional characteristics and the use of the boots worn by the police officers while they are on duty patrol walking on Florianópolis streets, as well as the influency of the boots in this activity. Selected by not-probabilistic sampling in a casual-systematic way, 234 police officers volunteered to take part in this study. The instrument used was a questionnaire assorted with clarity level of 0.93, validity of 0.85 and reliability of 0.95. According to the results, most police officers have only a pair of boots, which were worn on average 11 hours daily. To the boot usage was attributed the incidence of foot injuries such as callosity, chilblain, embedded nails and blisters. For these police officers the discomforts (overheating, pain and humidity on the feet as well as pain in the body caused by the boot interfered in their work routine taking them to classified their shoes as inappropriate, following the criteria of comfort, safety and durability. Therefore, it was concluded that the boots seemed not to be the ideal shoes in terms of comfort and job performance, because they interfered in their daily routine, causing functional and structural adaptations in the human body during the performance of motor tasks. RESUMO Este estudo descritivo diagnóstico teve como objetivo avaliar as características funcionais e de uso do coturno utilizado pelos policiais militares que realizam a tarefa de locomoção a pé durante as rondas nas ruas de Florianópolis, bem como sua influência nesta atividade. Selecionados por amostragem não-probabilística, casualsistemática por voluntariado, participaram 234 policiais militares. O instrumento utilizado foi um questionário misto com índice de clareza de 0,93, validade de 0,85 e fidedignidade de 0,95. De acordo com os resultados, a maioria dos policiais possui apenas um par de coturnos, permanecendo em média 11 horas diárias com este

  12. Identification and mapping of quantitative trait loci controlling cold-tolerance of Chinese common wild rice (O. rufipogon Griff.) at booting to flowering stages

    Institute of Scientific and Technical Information of China (English)

    LIU Fengxia; SUN Chuanqing; TAN Lubin; FU Yongcai; LI Dejun; WANG Xiangkun

    2003-01-01

    An advanced backcross population of rice was used to identify the quantitative trait locus (QTL) controlling the cold-tolerance at booting to flowering stages. The recipient, Guichao 2 (GC2), was a commercial Indica rice; the donor Dongxiang common wild rice, was an accession of common wild rice (DXCWR, Oryza rufipogon Griff.). Three QTLs for cold-tolerance were detected on chromosomes 1, 6and 11. Two of them coming from DXCWR could enhance the cold-tolerance of the backcross progenies. Moreover, one sterility QTL that could reduce the seed set rate of the backcross progenies by 78% was mapped on chromosome 5.

  13. Numerical Simulation of Low Mach Number Fluid - Phenomena.

    Science.gov (United States)

    Reitsma, Scott H.

    A method for the numerical simulation of low Mach number (M) fluid-acoustic phenomena is developed. This computational fluid-acoustic (CFA) methodology is based upon a set of conservation equations, termed finite-compressible, derived from the unsteady Navier-Stokes equations. The finite-compressible and more familiar pseudo-compressible equations are compared. The impact of derivation assumptions are examined theoretically and through numerical experimentation. The error associated with these simplifications is shown to be of O(M) and proportional to the amplitude of unsteady phenomena. A computer code for the solution of the finite -compressible equations is developed from an existing pseudo -compressible code. Spatial and temporal discretization issues relevant in the context of near field fluid-acoustic simulations are discussed. The finite volume code employs a MUSCL based third order upwind biased flux difference splitting algorithm for the convective terms. An explicit, three stage, second order Runge-Kutta temporal integration is employed for time accurate simulations while an implicit, approximately factored time quadrature is available for steady state convergence acceleration. The CFA methodology is tested in a series of problems which examine the appropriateness of the governing equations, the exacerbation of spatial truncation errors and the degree of temporal accuracy. Characteristic based boundary conditions employing a spatial formulation are developed. An original non-reflective boundary condition based upon the generalization and extension of existing methods is derived and tested in a series of multi-dimensional problems including those involving viscous shear flows and propagating waves. The final numerical experiment is the simulation of boundary layer receptivity to acoustic disturbances. This represents the first simulation of receptivity at a surface inhomogeneity in which the acoustic phenomena is modeled using physically appropriate

  14. A Mach-Zender Holographic Microscope for Quantifying Bacterial Motility

    Science.gov (United States)

    Niraula, B.; Nadeau, J. L.; Serabyn, E.; Wallace, J. K.; Liewer, K.; Kuhn, J.; Graff, E.; Lindensmith, C.

    2014-12-01

    New microscopic techniques have revolutionized cell biology over the past two decades. However, there are still biological processes whose details elude us, especially those involving motility: e.g. feeding behavior of microorganisms in the ocean, or migration of cancer cells to form metastases. Imaging prokaryotes, which range in size from several hundred nm to a few microns, is especially challenging. An emerging technique to address these issues is Digital Holographic Microscopy (DHM). DHM is an imaging technique that uses the interference of light to record and reproduce three-dimensional magnified images of objects. This approach has several advantages over ordinary brightfield microscopy for fieldwork: a larger depth of field, hands-off operation, robustness regarding environmental conditions, and large sampling volumes with quantitative 3D records of motility behavior. Despite these promising features, real-time DHM was thought to be impractical for technological and computational reasons until recently, and there has so far been very limited application of DHM to biology. Most existing instruments are limited in performance by their particular (e.g. in-line, lens-less, phase-shifting) approach to holography. These limitations can be mitigated with an off-axis dual-path configuration. Here we describe the design and implementation of a design for a Mach-Zehnder-type holographic microscope with diffraction-limited lateral resolution, with intended applications in environmental microbiology. We have achieved sub-micron resolution and three-dimensional tracking of prokaryotic and eukaryotic test strains designed to represent different modes and speeds of microbial motility. Prokaryotes are Escherichia coli, Vibrio alginolyticus, and Bacillus subtilis. Each shows a characteristic motility pattern, as we illustrate in holographic videos in sample chambers 0.6 mm in depth. The ability to establish gradients of attractants with bacterial taxis towards the

  15. Mach-Zehnder fiber interferometer for people monitoring

    Science.gov (United States)

    Vasinek, Vladimir; Latal, Jan; Koudelka, Petr; Siska, Petr; Vitasek, Jan; Skapa, Jan

    2010-10-01

    Fiber optical interferometers belong to highly sensitive equipments that are able to measure slight changes like distortion of shape, temperature and electric field variation and etc. Their great advantage is that they are insensitive on ageing component, from which they are composed of. It is in virtue of herewith, that there are evaluated no changes in optical signal intensity but number interference fringes. To monitor the movement of persons, eventually to analyze the changes in state of motion we developed method based on analysis the dynamic changes in interferometric pattern. We have used Mach- Zehnder interferometer with conventional SM fibers excited with the DFB laser at wavelength of 1550 nm. It was terminated with optical receiver containing InGaAs PIN photodiode. Its output was brought into measuring card module that performs on FFT of the received interferometer signal. The signal rises with the composition of two waves passing through single interferometer arm. The optical fiber SMF 28e in one arm is referential; the second one is positioned on measuring slab at dimensions of 1x2m. A movement of persons over the slab was monitored, signal processed with FFT and frequency spectra were evaluated. They rose owing to dynamic changes of interferometric pattern. The results reflect that the individual subjects passing through slab embody characteristic frequency spectra, which are individual for particular persons. The scope of measuring frequencies proceeded from zero to 10 KHz. It was also displayed in experiments that the experimental subjects, who walked around the slab and at the same time they have had changed their state of motion (knee joint fixation), embodied characteristic changes in their frequency spectra. At experiments the stability of interferometric patterns was evaluated as from time aspects, so from the view of repeated identical experiments. Two kinds of balls (tennis and ping-pong) were used to plot the repeatability measurements and

  16. Highlights from a Mach 4 Experimental Demonstration of Inlet Mode Transition for Turbine-Based Combined Cycle Hypersonic Propulsion

    Science.gov (United States)

    Foster, Lancert E.; Saunders, John D., Jr.; Sanders, Bobby W.; Weir, Lois J.

    2012-01-01

    NASA is focused on technologies for combined cycle, air-breathing propulsion systems to enable reusable launch systems for access to space. Turbine Based Combined Cycle (TBCC) propulsion systems offer specific impulse (Isp) improvements over rocket-based propulsion systems in the subsonic takeoff and return mission segments along with improved safety. Among the most critical TBCC enabling technologies are: 1) mode transition from the low speed propulsion system to the high speed propulsion system, 2) high Mach turbine engine development and 3) innovative turbine based combined cycle integration. To address these challenges, NASA initiated an experimental mode transition task including analytical methods to assess the state-of-the-art of propulsion system performance and design codes. One effort has been the Combined-Cycle Engine Large Scale Inlet Mode Transition Experiment (CCE-LIMX) which is a fully integrated TBCC propulsion system with flowpath sizing consistent with previous NASA and DoD proposed Hypersonic experimental flight test plans. This experiment was tested in the NASA GRC 10 by 10-Foot Supersonic Wind Tunnel (SWT) Facility. The goal of this activity is to address key hypersonic combined-cycle engine issues including: (1) dual integrated inlet operability and performance issues-unstart constraints, distortion constraints, bleed requirements, and controls, (2) mode-transition sequence elements caused by switching between the turbine and the ramjet/scramjet flowpaths (imposed variable geometry requirements), and (3) turbine engine transients (and associated time scales) during transition. Testing of the initial inlet and dynamic characterization phases were completed and smooth mode transition was demonstrated. A database focused on a Mach 4 transition speed with limited off-design elements was developed and will serve to guide future TBCC system studies and to validate higher level analyses.

  17. 基于Windows系统启动Linux的设计与实现%Design and Implementation of Booting Linux Based on Windows system

    Institute of Scientific and Technical Information of China (English)

    兰强

    2013-01-01

      为了解决在一台计算机上安装Windows和Linux,且相互影响最小,以Windows XP和Fedora 8.0为例,根据操作系统的启动原理,使用Linux磁盘管理命令设计并实现了从Windows启动Linux,优点在于删除Linux对Win-dows无任何影响,进而可以在此基础上设计并实现Windows启动多个操作系统.%In order to solve the installation of Windows and Linux on a computer, and minimize the mutual influence based on Windows XP and Fedora 8 as an example, booting Linux from Windows are designed and implemented in this article. It’s advantage is to remove or change Linux without any effect on Windows. On this basis, Booting multi operation system from Windows can be designed and implemented. This is a good choice for the Windows-based users to learn and research Linux system at present.

  18. Variations in battery life of a heart-lung machine using different pump speeds, pressure loads, boot material, centrifugal pump head, multiple pump usage, and battery age.

    LENUS (Irish Health Repository)

    Marshall, Cornelius

    2012-02-03

    Electrical failure during cardiopulmonary bypass (CPB) has previously been reported to occur in 1 of every 1500 cases. Most heart-lung machine pump consoles are equipped with built-in battery back-up units. Battery run times of these devices are variable and have not been reported. Different conditions of use can extend battery life in the event of electrical failure. This study was designed to examine the run time of a fully charged battery under various conditions of pump speed, pressure loads, pump boot material, multiple pump usage, and battery life. Battery life using a centrifugal pump also was examined. The results of this study show that battery life is affected by pump speed, circuit pressure, boot stiffness, and the number of pumps in service. Centrifugal pumps also show a reduced drain on battery when compared with roller pumps. These elements affect the longevity and performance of the battery. This information could be of value to the individual during power failure as these are variables that can affect the battery life during such a challenging scenario.

  19. Increased Mach Number Capability for the NASA Glenn 10x10 Supersonic Wind Tunnel

    Science.gov (United States)

    Slater, J. W.; Saunders, J. D.

    2015-01-01

    Computational simulations and wind tunnel testing were conducted to explore the operation of the Abe Silverstein Supersonic Wind Tunnel at the NASA Glenn Research Center at test section Mach numbers above the current limit of Mach 3.5. An increased Mach number would enhance the capability for testing of supersonic and hypersonic propulsion systems. The focus of the explorations was on understanding the flow within the second throat of the tunnel, which is downstream of the test section and is where the supersonic flow decelerates to subsonic flow. Methods of computational fluid dynamics (CFD) were applied to provide details of the shock boundary layer structure and to estimate losses in total pressure. The CFD simulations indicated that the tunnel could be operated up to Mach 4.0 if the minimum width of the second throat was made smaller than that used for previous operation of the tunnel. Wind tunnel testing was able to confirm such operation of the tunnel at Mach 3.6 and 3.7 before a hydraulic failure caused a stop to the testing. CFD simulations performed after the wind tunnel testing showed good agreement with test data consisting of static pressures along the ceiling of the second throat. The CFD analyses showed increased shockwave boundary layer interactions, which was also observed as increased unsteadiness of dynamic pressures collected in the wind tunnel testing.

  20. The small-scale dynamo: Breaking universality at high Mach numbers

    CERN Document Server

    Schleicher, Dominik R G; Federrath, Christoph; Bovino, Stefano; Schmidt, Wolfram

    2013-01-01

    (Abridged) The small-scale dynamo may play a substantial role in magnetizing the Universe under a large range of conditions, including subsonic turbulence at low Mach numbers, highly supersonic turbulence at high Mach numbers and a large range of magnetic Prandtl numbers Pm, i.e. the ratio of kinetic viscosity to magnetic resistivity. Low Mach numbers may in particular lead to the well-known, incompressible Kolmogorov turbulence, while for high Mach numbers, we are in the highly compressible regime, thus close to Burgers turbulence. In this study, we explore whether in this large range of conditions, a universal behavior can be expected. Our starting point are previous investigations in the kinematic regime. Here, analytic studies based on the Kazantsev model have shown that the behavior of the dynamo depends significantly on Pm and the type of turbulence, and numerical simulations indicate a strong dependence of the growth rate on the Mach number of the flow. Once the magnetic field saturates on the current ...

  1. Positioning approach based on Mach-Zehnder fiber sensors and a DSP processor

    Science.gov (United States)

    Wan, Xiong; Du, Tingting; Zhang, Zhimin; Zhang, Huaming; Wang, Peng

    2013-12-01

    A positioning system based on Mach-Zehnder optical fiber interferometer is proposed, which can sense vibration information along the circumference of the fiber sensor and hence be applied to positioning invasions as a safe-guard system in residence communities. A cross-correlation algorithm fulfilled with a DSP processor has been adopted to calculate the time difference of two channels of the Mach-Zehnder optical fiber interferometer. A signal identification algorithm is proposed to decrease the workload of the DSP when no vibration occurs. An experiment with 11.28 kilometers sensing fiber has been carried out, whose results show the Mach-Zehnder positioning system identifies the position of vibration instantaneously and has a 44 meters positioning error within the total sensing distance.

  2. Concept development of a Mach 3.0 high-speed civil transport

    Science.gov (United States)

    Robins, A. Warner; Dollyhigh, Samuel M.; Beissner, Fred L., Jr.; Geiselhart, Karl; Martin, Glenn L.; Shields, E. W.; Swanson, E. E.; Coen, Peter G.; Morris, Shelby J., Jr.

    1988-01-01

    A baseline concept for a Mach 3.0 high-speed civil transport concept was developed as part of a national program with the goal that concepts and technologies be developed which will enable an effective long-range high-speed civil transport system. The Mach 3.0 concept reported represents an aggressive application of advanced technology to achieve the design goals. The level of technology is generally considered to be that which could have a demonstrated availability date of 1995 to 2000. The results indicate that aircraft are technically feasible that could carry 250 passengers at Mach 3.0 cruise for a 6500 nautical mile range at a size, weight and performance level that allows it to fit into the existing world airport structure. The details of the configuration development, aerodynamic design, propulsion system design and integration, mass properties, mission performance, and sizing are presented.

  3. Effect of Mach number on the efficiency of microwave energy deposition in supersonic flow

    Science.gov (United States)

    Lashkov, V. A.; Karpenko, A. G.; Khoronzhuk, R. S.; Mashek, I. Ch.

    2016-05-01

    The article is devoted to experimental and numerical studies of the efficiency of microwave energy deposition into a supersonic flow around the blunt cylinder at different Mach numbers. Identical conditions for energy deposition have been kept in the experiments, thus allowing to evaluate the pure effect of varying Mach number on the pressure drop. Euler equations are solved numerically to model the corresponding unsteady flow compressed gas. The results of numerical simulations are compared to the data obtained from the physical experiments. It is shown that the momentum, which the body receives during interaction of the gas domain modified by microwave discharge with a shock layer before the body, increases almost linearly with rising of Mach number and the efficiency of energy deposition also rises.

  4. Dynamics of compressional Mach cones in a strongly coupled complex plasma

    CERN Document Server

    Bandyopadhyay, P; Kadyan, Sangeeta; Sen, Abhijit

    2016-01-01

    Using a Generalised-Hydrodynamic (GH) fluid model we study the influence of strong coupling induced modification of the fluid compressibility on the dynamics of compressional Mach cones in a dusty plasma medium. A significant structural change of lateral wakes for a given Mach number and Epstein drag force is found in the strongly coupled regime. With the increase of fluid compressibility, the peak amplitude of the normalised perturbed dust density first increases and then decreases monotonically after reaching its maximum value. It is also noticed that the opening angle of the cone structure decreases with the increase of the compressibility of the medium and the arm of the Mach cone breaks up into small structures in the velocity vector profile when the coupling between the dust particles increases.

  5. Coherence of Mach fronts during heterogeneous supershear earthquake rupture propagation: Simulations and comparison with observations

    Science.gov (United States)

    Bizzarri, A.; Dunham, Eric M.; Spudich, P.

    2010-01-01

    We study how heterogeneous rupture propagation affects the coherence of shear and Rayleigh Mach wavefronts radiated by supershear earthquakes. We address this question using numerical simulations of ruptures on a planar, vertical strike-slip fault embedded in a three-dimensional, homogeneous, linear elastic half-space. Ruptures propagate spontaneously in accordance with a linear slip-weakening friction law through both homogeneous and heterogeneous initial shear stress fields. In the 3-D homogeneous case, rupture fronts are curved owing to interactions with the free surface and the finite fault width; however, this curvature does not greatly diminish the coherence of Mach fronts relative to cases in which the rupture front is constrained to be straight, as studied by Dunham and Bhat (2008a). Introducing heterogeneity in the initial shear stress distribution causes ruptures to propagate at speeds that locally fluctuate above and below the shear wave speed. Calculations of the Fourier amplitude spectra (FAS) of ground velocity time histories corroborate the kinematic results of Bizzarri and Spudich (2008a): (1) The ground motion of a supershear rupture is richer in high frequency with respect to a subshear one. (2) When a Mach pulse is present, its high frequency content overwhelms that arising from stress heterogeneity. Present numerical experiments indicate that a Mach pulse causes approximately an ω−1.7 high frequency falloff in the FAS of ground displacement. Moreover, within the context of the employed representation of heterogeneities and over the range of parameter space that is accessible with current computational resources, our simulations suggest that while heterogeneities reduce peak ground velocity and diminish the coherence of the Mach fronts, ground motion at stations experiencing Mach pulses should be richer in high frequencies compared to stations without Mach pulses. In contrast to the foregoing theoretical results, we find no average elevation

  6. Edge and divertor plasma measurements with ion sensitive and Mach probes in LHD

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Y., E-mail: shihaya_uki884@yahoo.co.jp [Nagano National College of Technology, 716 Tokuma, Nagano 381-8550 (Japan); Ezumi, N. [Nagano National College of Technology, 716 Tokuma, Nagano 381-8550 (Japan); Masuzaki, S.; Tanaka, H.; Kobayashi, M. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Sawada, K. [Shinshu University, Wakasato, Nagano 380-8553 (Japan); Ohno, N. [Nagoya University, Furo-cho Chikusa-ku, Nagoya 464-8603 (Japan)

    2013-07-15

    Spatial profiles of plasma flow and Mach number in the stochastic magnetic boundary layer as well as ion temperature (T{sub i}) and electron temperature (T{sub e}) in the divertor region in Large Helical Device (LHD) have been studied by a movable multiple functions probe, which consists of Mach probes and an ion sensitive probe. The results of ion saturation current measurements indicated plasma flow direction is alternated in the stochastic magnetic boundary. Mach number profiles for different plasma densities have been evaluated experimentally which compared with 3-D transport code. T{sub i} and T{sub e} in the divertor region measured by the ion sensitive probe decreased with increasing line-averaged density. Although T{sub i} was higher than T{sub e} in the low density plasma, both temperatures became almost the same at higher density.

  7. Mach-wave coherence in 3D media with random heterogeneities

    Science.gov (United States)

    Vyas, Jagdish C.; Mai, P. Martin; Galis, Martin; Dunham, Eric M.; Imperatori, Walter

    2016-04-01

    We investigate Mach-waves coherence for complex super-shear ruptures embedded in 3D random media that lead to seismic scattering. We simulate Mach-wave using kinematic earthquake sources that include fault-regions over which the rupture propagates at super-shear speed. The local slip rate is modeled with the regularized Yoffe function. The medium heterogeneities are characterized by Von Karman correlation function. We consider various realizations of 3D random media from combinations of different values of correlation length (0.5 km, 2 km, 5 km), standard deviation (5%, 10%, 15%) and Hurst exponent (0.2). Simulations in a homogeneous medium serve as a reference case. The ground-motion simulations (maximum resolved frequency of 5 Hz) are conducted by solving the elasto-dynamic equations of motions using a generalized finite-difference method, assuming a vertical strike-slip fault. The seismic wavefield is sampled at numerous locations within the Mach-cone region to study the properties and evolution of the Mach-waves in scattering media. We find that the medium scattering from random heterogeneities significantly diminishes the coherence of Mach-wave in terms of both amplitude and frequencies. We observe that Mach-waves are considerably scattered at distances RJB > 20 km (and beyond) for random media with standard deviation 10%. The scattering efficiency of the medium for small Hurst exponents (H seismic scattering. We suggest that if an earthquake is recorded within 10-15 km fault perpendicular distance and has high PGA, then inversion should be carried out by allowing rupture speed variations from sub-Rayleigh to super-shear.

  8. Dispersive nature of high mach number collisionless plasma shocks: Poynting flux of oblique whistler waves.

    Science.gov (United States)

    Sundkvist, David; Krasnoselskikh, V; Bale, S D; Schwartz, S J; Soucek, J; Mozer, F

    2012-01-13

    Whistler wave trains are observed in the foot region of high Mach number quasiperpendicular shocks. The waves are oblique with respect to the ambient magnetic field as well as the shock normal. The Poynting flux of the waves is directed upstream in the shock normal frame starting from the ramp of the shock. This suggests that the waves are an integral part of the shock structure with the dispersive shock as the source of the waves. These observations lead to the conclusion that the shock ramp structure of supercritical high Mach number shocks is formed as a balance of dispersion and nonlinearity.

  9. Mach-Zehnder Modulator Performance on the NIF South Pole Bang Time Diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Beeman, B.; MacPhee, A. G.; Kimbrough, J. R.; Chow, R.; Carpenter, A.; Bond, E.; Zayas-Rivera, Z.; Bell, P.; Celeste, J.; Clancy, T.; Miller, E. K.; Edgell, D.; Donaldson, W. R.

    2013-09-01

    We present performance data for Mach-Zehnder optical modulators fielded on the National Ignition Facility (NIF) as a potential signal path upgrade for the South Pole Bang Time diagnostic. A single channel demonstration system has been deployed utilizing two modulators operating in a 90-degree In phase and Quadrature (I/Q) configuration. X-ray target emission signals are split and fed into two recording systems: a reference CRT based oscilloscope, Greenfield FTD10000, and the dual Mach-Zehnder system. Results of X-ray implosion time (bang time) determination from these two recording systems are compared and presented.

  10. Hydrodynamic Flow and Jet Induced Mach Shocks at RHIC and LHC

    CERN Document Server

    Stöcker, H; Rau, P; Betz, Barbara; Rau, Philip; St\\"ocker, Horst

    2007-01-01

    We discuss the present collective flow signals for the phase transition to quark-gluon plasma (QGP) and the collective flow as a barometer for the equation of state (EoS). A study of Mach shocks induced by fast partonic jets propagating through the QGP is given. We predict a significant deformation of Mach shocks in central Au+Au collisions at RHIC and LHC energies as compared to the case of jet propagation in a static medium. Results of a hydrodynamical study of jet energy loss are presented.

  11. A comparative study of scramjet injection strategies for high Mach numbers flows

    Science.gov (United States)

    Riggins, D. W.; Mcclinton, C. R.; Rogers, R. C.; Bittner, R. D.

    1992-01-01

    A simple method for predicting the axial distribution of supersonic combustor thrust potential is described. A complementary technique for illustrating the spatial evolution and distribution of thrust potential and loss mechanisms in reacting flows is developed. Wall jet cases and swept ramp injector cases for Mach 17 and Mach 13.5 flight enthalpy inflow conditions are numerically modeled and analyzed using these techniques. The visualization of thrust potential in the combustor for the various cases examined provides a unique tool for increasing understanding of supersonic combustor performance potential.

  12. Buses, Bikes or Boots

    Institute of Scientific and Technical Information of China (English)

    MICHAEL O'NEAL

    2010-01-01

    @@ If you have been in Beijing for any length of time, you will have come to realize that there are several modes of trans-portation available to commuters, all of them relatively inexpensive, especially when compared to fares in the Western world. The choice is not only a matter of frugality, but also of convenience, comfort and speed.

  13. An Improved TIC6xDSP System Fast Boot Mode%一种改进的TIC6xDSP系统的快速自举方式

    Institute of Scientific and Technical Information of China (English)

    刘歆浏; 周建平; 李健; 田瑞娟

    2014-01-01

    For accelerating DSP boot speed and improving program running efficiency, put forward an improved TIC6xDSP system fast boot mode. Taking TMS320C6455 as example, the whole process of TIC6xDSP’s boot is analyzed, including fundamental principle, hardware and interface design, flash burn and software design. Meanwhile, aiming at the problem of existing solutions, 3 aspects are proposed for improving, such as loading mode design, boot programming and integration of destination code. The results show that the method can greatly accelerate DSP boot speed and improve program running efficiency, and reduce difficulties for DSP research and development.%为提高 DSP 的自举速度和程序运行效率,提出一种改进的 TIC6xDSP 系统的快速自举方式。以TMS320C6455为例,详细分析 TIC6xDSP 自举的基本原理、硬件接口设计、Flash 烧写固化以及软件实现全过程。针对现有解决方案存在的弊端,从加载模式设计、引导程序编写以及目标代码整合3方面进行改进。结果表明:该方法能极大地提高DSP的自举速度和程序运行效率,降低程序员对DSP的开发难度。

  14. Energy, Metaphysics, and Space: Ernst Mach's Interpretation of Energy Conservation as the Principle of Causality

    Science.gov (United States)

    Guzzardi, Luca

    2014-01-01

    This paper discusses Ernst Mach's interpretation of the principle of energy conservation (EC) in the context of the development of energy concepts and ideas about causality in nineteenth-century physics and theory of science. In doing this, it focuses on the close relationship between causality, energy conservation and space in Mach's…

  15. Experimental investigation of liquid jet injection into Mach 6 hypersonic crossflow

    NARCIS (Netherlands)

    Beloki Perurena, J.; Asma, C.O.; Theunissen, R.; Chazot, O.

    2008-01-01

    The injection of a liquid jet into a crossing Mach 6 air flow is investigated. Experiments were conducted on a sharp leading edge flat plate with flush mounted injectors. Water jets were introduced through different nozzle shapes at relevant jet-to-air momentum-flux ratios. Sufficient temporal

  16. Mach 5 to 7 RBCC Propulsion System Testing at NASA-LeRC HTF

    Science.gov (United States)

    Perkins, H. Douglas; Thomas, Scott R.; Pack, William D.

    1996-01-01

    A series of Mach 5 to 7 freejet tests of a Rocket Based Combined Cycle (RBCC) engine were cnducted at the NASA Lewis Research Center (LERC) Hypersonic Tunnel Facility (HTF). This paper describes the configuration and operation of the HTF and the RBCC engine during these tests. A number of facility support systems are described which were added or modified to enhance the HTF test capability for conducting this experiment. The unfueled aerodynamic perfor- mance of the RBCC engine flowpath is also presented and compared to sub-scale test results previously obtained in the NASA LERC I x I Supersonic Wind Tunnel (SWT) and to Computational Fluid Dynamic (CFD) analysis results. This test program demonstrated a successful configuration of the HTF for facility starting and operation with a generic RBCC type engine and an increased range of facility operating conditions. The ability of sub-scale testing and CFD analysis to predict flowpath performance was also shown. The HTF is a freejet, blowdown propulsion test facility that can simulate up to Mach 7 flight conditions with true air composition. Mach 5, 6, and 7 facility nozzles are available, each with an exit diameter of 42 in. This combination of clean air, large scale, and Mach 7 capabilities is unique to the HTF. This RBCC engine study is the first engine test program conducted at the HTF since 1974.

  17. Event-based simulation of single-photon beam splitters and Mach-Zehnder interferometers

    NARCIS (Netherlands)

    De Raedt, H; De Raedt, K; Michielsen, K

    2005-01-01

    We demonstrate that networks of locally connected processing units with a primitive learning capability exhibit a behavior that is usually only attributed to quantum systems. We describe networks that simulate single-photon beam splitter and Mach-Zehnder interferometer experiments on a causal, event

  18. Mach number study of supersonic turbulence: The properties of the density field

    CERN Document Server

    Konstandin, Lukas; Girichidis, Philipp; Peters, Thomas; Shetty, Rahul; Klessen, Ralf S

    2015-01-01

    We model driven, compressible, isothermal, turbulence with Mach numbers ranging from the subsonic ($\\mathcal{M} \\approx 0.65$) to the highly supersonic regime ($\\mathcal{M}\\approx 16 $). The forcing scheme consists both solenoidal (transverse) and compressive (longitudinal) modes in equal parts. We find a relation $\\sigma_{s}^2 = \\mathrm{b}\\log{(1+\\mathrm{b}^2\\mathcal{M}^2)}$ between the Mach number and the standard deviation of the logarithmic density with $\\mathrm{b} = 0.457 \\pm 0.007$. The density spectra follow $\\mathcal{D}(k,\\,\\mathcal{M}) \\propto k^{\\zeta(\\mathcal{M})}$ with scaling exponents depending on the Mach number. We find $\\zeta(\\mathcal{M}) = \\alpha \\mathcal{M}^{\\beta}$ with a coefficient $\\alpha$ that varies slightly with resolution, whereas $\\beta$ changes systematically. We extrapolate to the limit of infinite resolution and find $\\alpha = -1.91 \\pm 0.01,\\, \\beta =-0.30\\pm 0.03$. The dependence of the scaling exponent on the Mach number implies a fractal dimension $D=2+0.96 \\mathcal{M}^{-0.3...

  19. Analysing surface plasmon resonance phase sensor based on Mach-Zehnder interferometer technique using glycerin

    Science.gov (United States)

    Kashif, Muhammad; Bakar, A. Ashrif A.; Hashim, Fazida Hanim

    2016-12-01

    Surface Plasmon Resonance (SPR) based on Mach-Zehnder interferometer (MZI) is a very accurate tool for the detection and analysis of molecular interactions. The performance of the proposed SPR phase sensor is dependent upon multiple performance parameters that include sensitivity, repeatability, drift and the induction speed of fluid into the flow cell. The SPR Mach-Zehnder interferometer is tested for different glycerin-water concentrations to check its performance based on the different parameters. This paper highlights the enhancement of the performance of SPR phase technique based on MZI that is influenced by different parameters, measured using glycerin solutions. These four performance parameters can affect the performance of SPR based on MZI and have a particular impact on the sensor output. It also provides us information about suitable working conditions for the SPR Mach-Zehnder interferometer sensor. The experiment data shows that the sensor's sensitivity is high for small concentrations of glycerin-water mixtures. Also, any change in drift as well as in induction speed of fluid can affect the performance of SPR Mach-Zehnder interferometer. The sensitivity of SPR phase sensor is high as it can measure glycerin concentration as low as 0.05%.

  20. Dynamic transition from Mach to regular reflection of shock waves in a steady flow

    CSIR Research Space (South Africa)

    Naidoo, K

    2014-07-01

    Full Text Available decreased with increased rotation speed. The sensitivity of the transition angle to changing the rotation point from the trailing edge to the experimental model pivot point was investigated briefly at a free-stream Mach number of M=2.98 with M(subE)=-0...

  1. Experimental investigation of liquid jet injection into Mach 6 hypersonic crossflow

    NARCIS (Netherlands)

    Beloki Perurena, J.; Asma, C.O.; Theunissen, R.; Chazot, O.

    2008-01-01

    The injection of a liquid jet into a crossing Mach 6 air flow is investigated. Experiments were conducted on a sharp leading edge flat plate with flush mounted injectors. Water jets were introduced through different nozzle shapes at relevant jet-to-air momentum-flux ratios. Sufficient temporal resol

  2. All optical wavelength conversion by SOA's in a Mach-Zehnder configuration

    DEFF Research Database (Denmark)

    Durhuus, T.; Jørgensen, C.; Mikkelsen, Benny

    1994-01-01

    Penalty free wavelength conversion is demonstrated at 2.5 Gbit/s over a wavelength span of 12 nm by the use of semiconductor optical amplifier (SOA)'s in a Mach-Zehnder configuration. An increase in the extinction ratio is measured for the converted signal compared to the input signal implying si...... signal regeneration as well as wavelength conversion...

  3. A versatile all-optical modulator based on nonlinear Mach-Zehnder interferometers

    NARCIS (Netherlands)

    Krijnen, G.J.M.; Villeneuve, A.; Stegeman, G.I.; Lambeck, P.V.; Hoekstra, H.J.W.M.

    1994-01-01

    A device based on a Nonlinear Mach-Zehnder interferometer (NMI) which exploits cross-phase modulation of two co-propagating modes in bimodal branches has been described in this paper. The advantage of this device is that it becomes polarisation independent while keeping phase insensitive by using di

  4. Cultural Mirrors Made of Papier Mache: Challenging Misrepresentations of Indigenous Knowledges in Education through Media

    Science.gov (United States)

    Iseke, Judy

    2009-01-01

    Misrepresentation, appropriation, and denigrating Indigenous knowledge is still common practice in educational institutions despite efforts of critical educators to challenge these practices. One such challenge was to papier mache totem poles in an education institution's library in a faculty of education that houses teacher education programs. A…

  5. Incorporation of Mach's Principle in ΛFRW Cosmology that depends dynamically of the distance range

    Science.gov (United States)

    Falcon, N.

    2017-07-01

    It postulates a FRW cosmological model without dark matter and cosmological term depending the distance scale, in addition to incorporate Mach's principle, is consistent with the observations: rotation curves of the galaxies, the nucleosynthesis primordial and CMB. The dynamic expression of Cosmological term is an alternative to non-baryonic dark matter and a reinterpretation of dark energy.

  6. The realization of an integrated Mach-Zehnder waveguide immunosensor in silicon technology

    NARCIS (Netherlands)

    Schipper, E.F.; Brugman, A.M.; Lechuga, L.M.; Kooyman, R.P.H.; Greve, J.; Dominguez, C.

    1997-01-01

    We describe the realization of a symmetric integrated channel waveguide Mach-Zehnder sensor which uses the evanescent field to detect small refractive-index changes (¿nmin ¿ 1 × 10¿4) near the guiding-layer surface. This guiding layer consists of ridge structures with a height of 3 nm and a width of

  7. On the Use of a Virtual Mach-Zehnder Interferometer in the Teaching of Quantum Mechanics

    Science.gov (United States)

    Pereira, Alexsandro; Ostermann, Fernanda; Cavalcanti, Claudio

    2009-01-01

    For many students, the conceptual learning of quantum mechanics can be rather painful owing to the counter-intuitive nature of quantum phenomena. In order to enhance students' understanding of the odd behaviour of photons and electrons, we introduce a computational simulation of the Mach-Zehnder interferometer, developed by our research group. An…

  8. On the Use of a Virtual Mach-Zehnder Interferometer in the Teaching of Quantum Mechanics

    Science.gov (United States)

    Pereira, Alexsandro; Ostermann, Fernanda; Cavalcanti, Claudio

    2009-01-01

    For many students, the conceptual learning of quantum mechanics can be rather painful owing to the counter-intuitive nature of quantum phenomena. In order to enhance students' understanding of the odd behaviour of photons and electrons, we introduce a computational simulation of the Mach-Zehnder interferometer, developed by our research group. An…

  9. Combustion-Powered Actuation for Dynamic Stall Suppression - Simulations and Low-Mach Experiments

    Science.gov (United States)

    Matalanis, Claude G.; Min, Byung-Young; Bowles, Patrick O.; Jee, Solkeun; Wake, Brian E.; Crittenden, Tom; Woo, George; Glezer, Ari

    2014-01-01

    An investigation on dynamic-stall suppression capabilities of combustion-powered actuation (COMPACT) applied to a tabbed VR-12 airfoil is presented. In the first section, results from computational fluid dynamics (CFD) simulations carried out at Mach numbers from 0.3 to 0.5 are presented. Several geometric parameters are varied including the slot chordwise location and angle. Actuation pulse amplitude, frequency, and timing are also varied. The simulations suggest that cycle-averaged lift increases of approximately 4% and 8% with respect to the baseline airfoil are possible at Mach numbers of 0.4 and 0.3 for deep and near-deep dynamic-stall conditions. In the second section, static-stall results from low-speed wind-tunnel experiments are presented. Low-speed experiments and high-speed CFD suggest that slots oriented tangential to the airfoil surface produce stronger benefits than slots oriented normal to the chordline. Low-speed experiments confirm that chordwise slot locations suitable for Mach 0.3-0.4 stall suppression (based on CFD) will also be effective at lower Mach numbers.

  10. The Contribution of Ernst Mach to Embodied Cognition and Mathematics Education

    Science.gov (United States)

    Zudini, Verena; Zuccheri, Luciana

    2016-01-01

    A study of the interactions between mathematics and cognitive science, carried out within a historical perspective, is important for a better understanding of mathematics education in the present. This is evident when analysing the contribution made by the epistemological theories of Ernst Mach. On the basis of such theories, a didactic method was…

  11. A suggested emergency medicine boot camp curriculum for medical students based on the mapping of Core Entrustable Professional Activities to Emergency Medicine Level 1 milestones

    Directory of Open Access Journals (Sweden)

    Lamba S

    2016-03-01

    Full Text Available Sangeeta Lamba, Bryan Wilson, Brenda Natal, Roxanne Nagurka, Michael Anana, Harsh Sule Department of Emergency Medicine, Rutgers New Jersey Medical School, Newark, NJ, USA Background: An increasing number of students rank Emergency Medicine (EM as a top specialty choice, requiring medical schools to provide adequate exposure to EM. The Core Entrustable Professional Activities (EPAs for Entering Residency by the Association of American Medical Colleges combined with the Milestone Project for EM residency training has attempted to standardize the undergraduate and graduate medical education goals. However, it remains unclear as to how the EPAs correlate to the milestones, and who owns the process of ensuring that an entering EM resident has competency at a certain minimum level. Recent trends establishing specialty-specific boot camps prepare students for residency and address the variability of skills of students coming from different medical schools. Objective: Our project’s goal was therefore to perform a needs assessment to inform the design of an EM boot camp curriculum. Toward this goal, we 1 mapped the core EPAs for graduating medical students to the EM residency Level 1 milestones in order to identify the possible gaps/needs and 2 conducted a pilot procedure workshop that was designed to address some of the identified gaps/needs in procedural skills. Methods: In order to inform the curriculum of an EM boot camp, we used a systematic approach to 1 identify gaps between the EPAs and EM milestones (Level 1 and 2 determine what essential and supplemental competencies/skills an incoming EM resident should ideally possess. We then piloted a 1-day, three-station advanced ABCs procedure workshop based on the identified needs. A pre-workshop test and survey assessed knowledge, preparedness, confidence, and perceived competence. A post-workshop survey evaluated the program, and a posttest combined with psychomotor skills test using three

  12. Radiographic and functional results in the treatment of early stages of Charcot neuroarthropathy with a walker boot and immediate weight bearing

    Directory of Open Access Journals (Sweden)

    Maria Candida Ribeiro Parisi

    2013-10-01

    Full Text Available Background: One of the most common gold standards for the treatment of Charcot neuroarthropathy (CN in the early Eichenholtz stages I and II is immobilization with the total contact casting and lower limb offloading. However, the total amount of offloading is still debatable. Objectives: This study evaluates the clinical and radiographic findings in the treatment of early stages of CN (Eichenholtz stages I and II with a walker boot and immediate total weight-bearing status. Methods: Twenty-two patients with type 2 diabetes mellitus (DM and CN of Eichenholtz stages I and II were selected for non-operative treatment. All patients were educated about their condition, and full weight bearing was allowed as tolerated. Patients were monitored on a fortnightly basis in the earlier stages, with clinical examination, temperature measurement, and standardized weight-bearing radiographs. Their American Orthopedic Foot and Ankle Society (AOFAS scores were determined before and after the treatment protocol. Results: No cutaneous ulcerations or infections were observed in the evaluated cases. The mean measured angles at the beginning and end of the study, although showing relative increase, did not present a statistically significant difference (p > 0.05. Mean AOFAS scores showed a statistically significant improvement by the end of the study (p < 0.005. Conclusion: The treatment of early stages of CN (Eichenholtz stages I and II with emphasis on walker boot and immediate weight bearing has shown a good functional outcome, non-progressive deformity on radiographic assessment, and promising results as a safe treatment option.

  13. Cold Tolerance of Core Collection at Booting Stage Associated with Eco-geographic Distribution in Yunnan Rice Landrace (Oryza sativa),China

    Institute of Scientific and Technical Information of China (English)

    LI Shen-chong; LIU Jia-fu; ZENG Ya-wen; WANG Lu-xiang; SHEN Shi-quan; PU Xiao-ying; LI Zi-chao; WANG Xiangkun; WEN Guo-song; YANG Zhong-yi

    2004-01-01

    Four hundred and seventy-seven accessions of the second core collection of rice landrace from five rice cropping regions (16 prefectures) of Yunnan Province, China, were evaluated for cold tolerance at booting stage. The results showed as follows: 1) there was a significant positive correlation (0.588**) between anther length and seed setting rate under natural low temperature conditions but was not significant in greenhouse (0.080). 2) there were significant differences in cold tolerance among cora collections from different cropping regions under natural low temperature conditions while a negligible cold damage in greenhouse (with a seed setting rate approaching or exceeding 70%) for cold tolerance evaluation. Cold tolerance of core collection from Northwest Yunnan cold highland japonica region was the strongest, and that from south marginal paddy-upland rice region was the most sensitive, suggesting that the breeding goals for cold tolerance should be different in various rice cropping regions. 3) there were remarkable differences in cold tolerance of core collections from different prefectures of Yunnan Province under natural low temperature conditions. Based on the reduction of seed setting rate and characteristics of natural climate, the 16prefectures could be divided into three categories, i.e. serious cold damage, cold damage and slight cold damage regions. 4)Difference of cold tolerance between different rice cropping regions and prefectures revealed further that temperature change caused by elevation and latitude was not only a dominant factor for differentiation of japonica and indica but also the basic reason that the genetic diversity and six ecological group of indica and japonica were being developed and, even the critical factor leading to the formation of the cold tolerance gene as well. The cold tolerance at booting stage could be believed to be resulted from the long term co-evolution between Yunnan rice landrce and cold stress in rice cropping

  14. An Investigation of Transonic Resonance in a Mach 2.2 Round Convergent-Divergent Nozzle

    Science.gov (United States)

    Dippold, Vance F., III; Zaman, Khairul B. M. Q.

    2015-01-01

    Hot-wire and acoustic measurements were taken for a round convergent nozzle and a round convergent-divergent (C-D) nozzle at a jet Mach number of 0.61. The C-D nozzle had a design Mach number of 2.2. Compared to the convergent nozzle jet flow, the Mach 2.2 nozzle jet flow produced excess broadband noise (EBBN). It also produced a transonic resonance tone at 1200 Herz. Computational simulations were performed for both nozzle flows. A steady Reynolds-Averaged Navier-Stokes simulation was performed for the convergent nozzle jet flow. For the Mach 2.2 nozzle flow, a steady RANS simulation, an unsteady RANS (URANS) simulation, and an unsteady Detached Eddy Simulation (DES) were performed. The RANS simulation of the convergent nozzle showed good agreement with the hot-wire velocity and turbulence measurements, though the decay of the potential core was over-predicted. The RANS simulation of the Mach 2.2 nozzle showed poor agreement with the experimental data, and more closely resembled an ideally-expanded jet. The URANS simulation also showed qualitative agreement with the hot-wire data, but predicted a transonic resonance at 1145 Herz. The DES showed good agreement with the hot-wire velocity and turbulence data. The DES also produced a transonic tone at 1135 Herz. The DES solution showed that the destabilization of the shock-induced separation region inside the nozzle produced increased levels of turbulence intensity. This is likely the source of the EBBN.

  15. Distributed optical fiber perturbation sensing system based on Mach-Zehnder interferometer

    Institute of Scientific and Technical Information of China (English)

    Wengang WANG; Deming LIU; Hairong LIU; Qizhen SUN; Zhifeng SUN; Xu ZHANG; Ziheng XU

    2009-01-01

    A novel distributed optical fiber vibration-sensing system based on Mach-Zehnder interferometer has been designed and experimentally demonstrated. Firstly, the principle of Mach-Zehnder optical path interferometer technique is clarified. The output of the Mach-Zehnder interferometer is proportional to the phase shift induced by the perturbation. Secondly, the system consists of the laser diode (LD) as the light source, fiber, Mach-Zehnder optical interferometers as the sensing units, a 1×N star fiber-optic coupler, an N×1 fiber-optic coupler, a photodiode (PD) detector, and a computer used in signal processing. The entire monitoring region of this system is divided into several small zones, and each small monitoring zone is independent from each other. All of the small monitoring zones have their own sensing unit, which is defined by Mach-Zehnder optical interferometer. A series of sensing units are connected by the star fiber-optic couplers to form a whole sensing net. Thirdly, signal-processing techniques are subsequently used to calculate the phase shift to estimate whether intruders appear. The sensing system is able to locate the vibration signal simultaneously, includ-ing multiple vibrations at different positions, by employing the time-division multiplexed (TDM) technique. Finally, the operation performance of the proposed system is tested in the experiment lab with the conditions as follows: the number of the sensing units is 3, the length of the sensing fiber is 50 m, and the wavelength of the light diode is 1550nm. Based on these investigations, the fiber surrounding alert system is achieved. We have experimen-tally demonstrated that the sensing system can measure both the frequency and position of the vibration in real time, with a spatial positional resolution better than 50 m in an area of 1 km2.

  16. Automatic sequences

    CERN Document Server

    Haeseler, Friedrich

    2003-01-01

    Automatic sequences are sequences which are produced by a finite automaton. Although they are not random they may look as being random. They are complicated, in the sense of not being not ultimately periodic, they may look rather complicated, in the sense that it may not be easy to name the rule by which the sequence is generated, however there exists a rule which generates the sequence. The concept automatic sequences has special applications in algebra, number theory, finite automata and formal languages, combinatorics on words. The text deals with different aspects of automatic sequences, in particular:· a general introduction to automatic sequences· the basic (combinatorial) properties of automatic sequences· the algebraic approach to automatic sequences· geometric objects related to automatic sequences.

  17. Wind-tunnel blockage and actuation systems test of a two-dimensional scramjet inlet unstart model at Mach 6

    Science.gov (United States)

    Holland, Scott D.

    1994-01-01

    The present study examines the wind-tunnel blockage and actuation systems effectiveness in starting and forcibly unstarting a two-dimensional scramjet inlet in the NASA Langley 20-Inch Mach 6 Tunnel. The intent of the overall test program is to study (both experimentally and computationally) the dynamics of the inlet unstart; however, prior to the design and fabrication of an expensive, instrumented wind-tunnel model, it was deemed necessary first to examine potential wind-tunnel blockage issues related to model sizing and to examine the adequacy of the actuation systems in accomplishing the start and unstart. The model is equipped with both a moveable cowl and aft plug. Windows in the inlet sidewalls allow limited optical access to the internal shock structure; schlieren video was used to identify inlet start and unstart. A chronology of each actuation sequence is provided in tabular form along with still frames from the schlieren video. A pitot probe monitored the freestream conditions throughout the start/unstart process to determine if there was a blockage effect due to the model start or unstart. Because the purpose of this report is to make the phase I (blockage and actuation systems) data rapidly available to the community, the data is presented largely without analysis of the internal shock interactions or the unstart process. This series of tests indicated that the model was appropriately sized for this facility and identified operability limits required first to allow the inlet to start and second to force the unstart.

  18. Ernst Mach, George Sarton and the Empiry of Teaching Science Part I

    Science.gov (United States)

    Siemsen, Hayo

    2012-04-01

    George Sarton had a strong influence on modern history of science. The method he pursued throughout his life was the method he had discovered in Ernst Mach's Mechanics when he was a student in Ghent. Sarton was in fact throughout his life implementing a research program inspired by the epistemology of Mach. Sarton in turn inspired many others (James Conant, Thomas Kuhn, Gerald Holton, etc.). What were the origins of these ideas in Mach and what can this origin tell us about the history of science and science education nowadays? Which ideas proved to be successful and which ones need to be improved upon? The following article will elaborate the epistemological questions, which Darwin's "Origin" raised concerning human knowledge and scientific knowledge and which led Mach to adapt the concept of what is "empirical" in contrast to metaphysical a priori assumptions a second time after Galileo. On this basis Sarton proposed "genesis and development" as the major goal of Isis. Mach had elaborated this epistemology in La Connaissance et l'Erreur ( Knowledge and Error), which Sarton read in 1913 (Hiebert 1905/1976; de Mey 1984). Accordingly for Sarton, history becomes not only a subject of science, but a method of science education. Culture—and science as part of culture—is a result of a genetic process. History of science shapes and is shaped by science and science education in a reciprocal process. Its epistemology needs to be adapted to scientific facts and the philosophy of science. Sarton was well aware of the need to develop the history of science and the philosophy of science along the lines of this reciprocal process. It was a very fruitful basis, but a specific part of it, Sarton did not elaborate further, namely the psychology of science education. This proved to be a crucial missing element for all of science education in Sarton's succession, especially in the US. Looking again at the origins of the central questions in the thinking of Mach, which provided

  19. Sequence assembly

    DEFF Research Database (Denmark)

    Scheibye-Alsing, Karsten; Hoffmann, S.; Frankel, Annett Maria

    2009-01-01

    Despite the rapidly increasing number of sequenced and re-sequenced genomes, many issues regarding the computational assembly of large-scale sequencing data have remain unresolved. Computational assembly is crucial in large genome projects as well for the evolving high-throughput technologies...

  20. Mach 6 flowfield survey at the engine inlet of a research airplane

    Science.gov (United States)

    Johnson, C. B.; Lawing, P. L.

    1977-01-01

    A flowfield survey was conducted to better define the nature of vehicle forebody flowfield at the inlet location of an airframe-integrated scramjet engine mounted on the lower surface of a high-speed research airplane to be air launched from a B-52 and rocket boosted to Mach 6. The tests were conducted on a 1/30-scale brass model in a Mach-6 20-in. wind tunnel at Reynolds number of 11,200,000 based on distance to engine inlet. Boundary layer profiles at five spanwise locations indicate that the boundary layer in the area of the forebody centerline is more than twice as thick as the boundary layer at three outboard stations. It is shown that the cold streak found in heating contours on the centerline of the forebody is caused by a thickening of the boundary layer on the centerline, and that this thickening decreases with angle of attack.

  1. Mach number scaling of helicopter rotor blade/vortex interaction noise

    Science.gov (United States)

    Leighton, Kenneth P.; Harris, Wesley L.

    1985-01-01

    A parametric study of model helicopter rotor blade slap due to blade vortex interaction (BVI) was conducted in a 5 by 7.5-foot anechoic wind tunnel using model helicopter rotors with two, three, and four blades. The results were compared with a previously developed Mach number scaling theory. Three- and four-bladed rotor configurations were found to show very good agreement with the Mach number to the sixth power law for all conditions tested. A reduction of conditions for which BVI blade slap is detected was observed for three-bladed rotors when compared to the two-bladed baseline. The advance ratio boundaries of the four-bladed rotor exhibited an angular dependence not present for the two-bladed configuration. The upper limits for the advance ratio boundaries of the four-bladed rotors increased with increasing rotational speed.

  2. Two-dimensional lattice Boltzmann model for compressible flows with high Mach number

    Science.gov (United States)

    Gan, Yanbiao; Xu, Aiguo; Zhang, Guangcai; Yu, Xijun; Li, Yingjun

    2008-03-01

    In this paper we present an improved lattice Boltzmann model for compressible Navier-Stokes system with high Mach number. The model is composed of three components: (i) the discrete-velocity-model by M. Watari and M. Tsutahara [Phys. Rev. E 67 (2003) 036306], (ii) a modified Lax-Wendroff finite difference scheme where reasonable dissipation and dispersion are naturally included, (iii) artificial viscosity. The improved model is convenient to compromise the high accuracy and stability. The included dispersion term can effectively reduce the numerical oscillation at discontinuity. The added artificial viscosity helps the scheme to satisfy the von Neumann stability condition. Shock tubes and shock reflections are used to validate the new scheme. In our numerical tests the Mach numbers are successfully increased up to 20 or higher. The flexibility of the new model makes it suitable for tracking shock waves with high accuracy and for investigating nonlinear nonequilibrium complex systems.

  3. Flow-induced cylinder noise formulated as a diffraction problem for low Mach numbers

    Science.gov (United States)

    Gloerfelt, X.; Pérot, F.; Bailly, C.; Juvé, D.

    2005-10-01

    The role of surfaces in the mechanism of sound generation by low Mach number flows interacting with solid nonvibrating surfaces is well established by the classical aeroacoustic papers by Powell, Doak, Ffowcs Williams, Crighton, or Howe. It can be formulated as a problem of diffraction of the flow sources by the rigid body. The present study illustrates this statement in the case of flow-induced cylinder noise. Curle's formulation is analytically and numerically compared to a formulation based on an exact Green's function tailored to a cylindrical geometry. The surface integral of Curle's formulation represents exactly the diffraction effects by the rigid body. The direct and scattered parts of the sound field are studied. In this low Mach number configuration, the cylinder is compact, and the scattered (dipole) field dominates the direct (quadrupole) field. The classical properties of the scattering by a cylinder are retrieved by considering a point quadripole source near the cylinder surface.

  4. A fast spatial scanning combination emissive and mach probe for edge plasma diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Lehmer, R.D.; LaBombard, B.; Conn, R.W.

    1989-04-01

    A fast spatially scanning emissive and mach probe has been developed for the measurement of plasma profiles in the PISCES facility at UCLA. A pneumatic cylinder is used to drive a multiple tip probe along a 15cm stroke in less than 400msec, giving single shot profiles while limiting power deposition to the probe. A differentially pumped sliding O-ring seal allows the probe to be moved between shots to infer two and three dimensional profiles. The probe system has been used to investigate the plasma potential, density, and parallel mach number profiles of the presheath induced by a wall surface and scrape-off-layer profile modifications in biased limiter simulation experiments. Details of the hardware, data acquisition electronics, and tests of probe reliability are discussed. 30 refs., 24 figs.

  5. Extension of the pressure correction method to zero-Mach number compressible flows

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In the present paper,the classical pressure correction method was extended into low Mach number compressible flow regime by integrating equation of state into SIMPLE algorithm.The self-developed code based on this algorithm was applied to predicting the lid-driven cavity flow and shock tube prob-lems,and the results showed good agreement with benchmark solutions and the Mach number can reach the magnitude of as low as 10-5.The attenuation of sound waves in viscous medium was then simulated.The results agree well with the analytical solutions given by theoretical acoustics.This demonstrated that the present method could also be implemented in acoustics field simulation,which is crucial for thermoacoustic simulation.

  6. The Density Variance--Mach Number Relation in Supersonic Turbulence: I. Isothermal, magnetised gas

    CERN Document Server

    Molina, F Z; Federrath, C; Klessen, R S

    2012-01-01

    It is widely accepted that supersonic, magnetised turbulence plays a fundamental role for star formation in molecular clouds. It produces the initial dense gas seeds out of which new stars can form. However, the exact relation between gas compression, turbulent Mach number, and magnetic field strength is still poorly understood. Here, we introduce and test an analytical prediction for the relation between the density variance and the root-mean-square Mach number in supersonic, isothermal, magnetised turbulent flows. We approximate the density and velocity structure of the interstellar medium as a superposition of shock waves. We obtain the density contrast considering the momentum continuity equation for a single magnetised shock and extrapolate this result to the entire cloud. Depending on the field geometry, we then make three different assumptions based on observational and theoretical constraints: B independent of density, B proportional to the root square of the density and B proportional to the density....

  7. Extension of the pressure correction method to zero-Mach number compressible flows

    Institute of Scientific and Technical Information of China (English)

    HE YaLing; HUANG Jing; TAO YuBing; TAO WenQuan

    2009-01-01

    In the present paper, the classical pressure correction method was extended into low Mach number compressible flow regime by integrating equation of state into SIMPLE algorithm. The self-developed code based on this algorithm was applied to predicting the lid-driven cavity flow and shock tube prob-lems, and the results showed good agreement with benchmark solutions and the Mach number can reach the magnitude of as low as 10-5. The attenuation of sound waves in viscous medium was then simulated. The results agree well with the analytical solutions given by theoretical acoustics. This demonstrated that the present method could also be implemented in acoustics field simulation, which is crucial for thermoacoustic simulation.

  8. Axisymmetric vortex method for low-Mach number, diffusion-controlled combustion

    CERN Document Server

    Lakkis, I

    2003-01-01

    A grid-free, Lagrangian method for the accurate simulation of low-Mach number, variable-density, diffusion-controlled reacting flow is presented. A fast-chemistry model in which the conversion rate of reactants to products is limited by the local mixing rate is assumed in order to reduce the combustion problem to the solution of a convection-diffusion-generation equation with volumetric expansion and vorticity generation at the reaction fronts. The solutions of the continuity and vorticity equations, and the equations governing the transport of species and energy, are obtained using a formulation in which particles transport conserved quantities by convection and diffusion. The dynamic impact of exothermic combustion is captured through accurate integration of source terms in the vorticity transport equations at the location of the particles, and the extra velocity field associated with volumetric expansion at low Mach number computed to enforced mass conservation. The formulation is obtained for an axisymmet...

  9. DNS study on shock/turbulence interaction in homogeneous isotropic turbulence at low turbulent Mach number

    Science.gov (United States)

    Tanaka, Kento; Watanabe, Tomoaki; Nagata, Koji; Sasoh, Akihiro; Sakai, Yasuhiko; Hayase, Toshiyuki; Nagoya Univ Collaboration

    2016-11-01

    The interaction between homogeneous isotropic turbulence and normal shock wave is investigated by direct numerical simulations (DNSs). In the DNSs, a normal shock wave with a shock Mach number 1.1 passes through homogeneous isotropic turbulence with a low turbulent Mach number and a moderate turbulent Reynolds number. The statistics are calculated conditioned on the distance from the shock wave. The results showed that the shock wave makes length scales related to turbulence small. This effect is significant for the Taylor microscale defined with the velocity derivative orthogonal to the shock wave. The decrease in the Kolmogorov scale is also found. Statistics of velocity derivative are found to be changed by the shock wave propagation. The shock wave causes enstrophy amplification due to the dilatation/vorticity interaction. By this interaction, the vorticity components parallel to the shock wave is more amplified than the normal component. The strain rate is also amplified by the shock wave.

  10. Cost-effective evolution of research prototypes into end-user tools: The MACH case study

    DEFF Research Database (Denmark)

    Störrle, Harald

    2017-01-01

    this issue; their steep learning curves constitute substantial entry barriers to such ecosystems. In this paper, we present the Model Analyzer/Checker (MACH), a stand-alone tool with a command-line interpreter. MACH integrates a set of research prototypes for analyzing UML models. By choosing a simple......Much of Software Engineering research needs to provide an implementation as proof-of-concept. Often such implementations are created as exploratory prototypes without polished user interfaces, making it difficult to (1) run user studies to validate the tool's contribution, (2) validate the author......'s claim by fellow scientists, and (3) demonstrate the utility and value of the research contribution to any interested parties. However, turning an exploratory prototype into a “proper” tool for end-users often entails great effort. Heavyweight mainstream frameworks such as Eclipse do not address...

  11. Stabilized fiber-optic Mach-Zehnder interferometer for carrier-frequency rejection

    CERN Document Server

    Cooper, Nathan; Bateman, James; Dunning, Alexander; Freegarde, Tim

    2013-01-01

    We have demonstrated stabilization of a fiber-optic Mach-Zehnder interferometer, with a centimeter-scale path difference, to the transmission minimum for the carrier wave of a frequency-modulated laser beam. A time-averaged extinction of 32 dB, limited by the bandwidth of the feedback, was maintained over several hours. The interferometer was used to remove the carrier wave from a 780 nm laser beam that had been phase modulated at 2.7 GHz.

  12. Comte, Mach, Planck, and Eddington: a study of influence across generations

    Science.gov (United States)

    Batten, Alan H.

    2016-04-01

    Auguste Comte is frequently ridiculed by astronomers for saying that human beings would never be able to know the physical nature and constitution of the stars. His philosophy, however, influenced scientists throughout his lifetime and for over a century after his death. That influence is traced here in the work of three outstanding scientists who spanned, roughly speaking, three successive generations after his own, namely, Ernst Mach, Max Planck and Arthur Stanley Eddington.

  13. Mach-Zehnder-based five-port silicon router for optical interconnects.

    Science.gov (United States)

    Li, Xianyao; Xiao, Xi; Xu, Hao; Li, Zhiyong; Chu, Tao; Yu, Jinzhong; Yu, Yude

    2013-05-15

    We propose and fabricate a five-port silicon optical router based on Mach-Zehnder interferometer switches. Only 10 switching elements and five low-loss waveguide crossings are required in our design. Through thermal control of the switching network, we successfully demonstrate 20 possible I/O paths of the five-port optical router at a data transmission rate of 32 Gb/s. The results here show great potential for application in ultrahigh-capacity optical interconnects.

  14. Nearfield Unsteady Pressures at Cruise Mach Numbers for a Model Scale Counter-Rotation Open Rotor

    Science.gov (United States)

    Stephens, David B.

    2012-01-01

    An open rotor experiment was conducted at cruise Mach numbers and the unsteady pressure in the nearfield was measured. The system included extensive performance measurements, which can help provide insight into the noise generating mechanisms in the absence of flow measurements. A set of data acquired at a constant blade pitch angle but various rotor speeds was examined. The tone levels generated by the front and rear rotor were found to be nearly equal when the thrust was evenly balanced between rotors.

  15. Planar Rayleigh scattering results in helium-air mixing experiments in a Mach-6 wind tunnel

    OpenAIRE

    Shirinzadeh, B.; Hillard, M. E.; Balla, R. Jeffrey; Waitz, I. A.; Anders, J. B.; Exton, R. J.

    1992-01-01

    Planar Rayleigh scattering measurements with an argon—fluoride excimer laser are performed to investigate helium mixing into air at supersonic speeds. The capability of the Rayleigh scattering technique for flow visualization of a turbulent environment is demonstrated in a large-scale, Mach-6 facility. The detection limit obtained with the present setup indicates that planar, quantitative measurements of density can be made over a large cross-sectional area (5 cm × 10 cm) of the flow field in...

  16. 基于龙芯2F的U-Boot固件移植与显卡优化%Firmware Porting and Video Card Optimization of U-Boot Based on Loongson 2F

    Institute of Scientific and Technical Information of China (English)

    何超勇; 钱晓捷

    2015-01-01

    In order to improve the extensibility of Yeeloong 8089 platform based on Loongson 2F, the basic structure and the porting process of the U-Boot firmware on this platform are described. The initialization process of PCI devices, especially of video care, is presented. The use of general graphic cards on the non-x86 architecture platform is implemented by introducing video graphics array (VGA) basic input/output system (BIOS) emulator into the U-Boot. The test results show that U-Boot can run stably on Yeeloong 8089 platform, and can correctly display the startup information through the video card and successfully boot the Debian Linux kernel.%为提高基于龙芯2F的Yeeloong 8089平台的扩展性,阐述了U-Boot固件的基本架构和在该平台上的移植过程。描述了PCI设备特别是显卡的初始化过程,通过在U-Boot中引入视频图形阵列(VGA)基本输入输出系统(BIOS)模拟器的方式解决了在非x86架构平台上使用通用显卡的问题。经过调试和验证,U-Boot稳定运行于Yeeloong 8089平台,能够通过显卡显示启动信息,并可以成功引导Debian Linux内核。

  17. Asymptotic preserving IMEX finite volume schemes for low Mach number Euler equations with gravitation

    Science.gov (United States)

    Bispen, Georgij; Lukáčová-Medvid'ová, Mária; Yelash, Leonid

    2017-04-01

    In this paper we will present and analyze a new class of the IMEX finite volume schemes for the Euler equations with a gravity source term. We will in particular concentrate on a singular limit of weakly compressible flows when the Mach number M ≪ 1. In order to efficiently resolve slow dynamics we split the whole nonlinear system in a stiff linear part governing the acoustic and gravity waves and a non-stiff nonlinear part that models nonlinear advection effects. For time discretization we use a special class of the so-called globally stiffly accurate IMEX schemes and approximate the stiff linear operator implicitly and the non-stiff nonlinear operator explicitly. For spatial discretization the finite volume approximation is used with the central and Rusanov/Lax-Friedrichs numerical fluxes for the linear and nonlinear subsystem, respectively. In the case of a constant background potential temperature we prove theoretically that the method is asymptotically consistent and asymptotically stable uniformly with respect to small Mach number. We also analyze experimentally convergence rates in the singular limit when the Mach number tends to zero.

  18. Krypton tagging velocimetry in a turbulent Mach 2.7 boundary layer

    Science.gov (United States)

    Zahradka, D.; Parziale, N. J.; Smith, M. S.; Marineau, E. C.

    2016-05-01

    The krypton tagging velocimetry (KTV) technique is applied to the turbulent boundary layer on the wall of the "Mach 3 Calibration Tunnel" at Arnold Engineering Development Complex (AEDC) White Oak. Profiles of velocity were measured with KTV and Pitot-pressure probes in the Mach 2.7 turbulent boundary layer comprised of 99 % {N}2/1 % Kr at momentum-thickness Reynolds numbers of {Re}_{\\varTheta }= 800, 1400, and 2400. Agreement between the KTV- and Pitot-derived velocity profiles is excellent. The KTV and Pitot velocity data follow the law of the wall in the logarithmic region with application of the Van Driest I transformation. The velocity data are analyzed in the outer region of the boundary layer with the law of the wake and a velocity-defect law. KTV-derived streamwise velocity fluctuation measurements are reported and are consistent with data from the literature. To enable near-wall measurement with KTV (y/δ ≈ 0.1-0.2), an 800-nm longpass filter was used to block the 760.2-nm read-laser pulse. With the longpass filter, the 819.0-nm emission from the re-excited Kr can be imaged to track the displacement of the metastable tracer without imaging the reflection and scatter from the read-laser off of solid surfaces. To operate the Mach 3 AEDC Calibration Tunnel at several discrete unit Reynolds numbers, a modification was required and is described herein.

  19. The Cosmic Mach Number: Comparison from Observations, Numerical Simulations and Nonlinear Predictions

    CERN Document Server

    Agarwal, Shankar

    2013-01-01

    We calculate the cosmic Mach number M - the ratio of the bulk flow of the velocity field on scale R to the velocity dispersion within regions of scale R. M is effectively a measure of the ratio of large-scale to small-scale power and can be a useful tool to constrain the cosmological parameter space. Using a compilation of existing peculiar velocity surveys, we calculate M and compare it to that estimated from mock catalogues extracted from the LasDamas (a LCDM cosmology) numerical simulations. We find agreement with expectations for the LasDamas cosmology at ~ 1.5 sigma CL. We also show that our Mach estimates for the mocks are not biased by selection function effects. To achieve this, we extract dense and nearly-isotropic distributions using Gaussian selection functions with the same width as the characteristic depth of the real surveys, and show that the Mach numbers estimated from the mocks are very similar to the values based on Gaussian profiles of the corresponding widths. We discuss the importance of ...

  20. Particle-in-cell simulations of particle energization from low Mach number fast mode shocks

    CERN Document Server

    Park, Jaehong; Blackman, Eric G; Ren, Chuang; Siller, Robert

    2012-01-01

    Astrophysical shocks are often studied in the high Mach number limit but weakly compressive fast shocks can occur in magnetic reconnection outflows and are considered to be a site of particle energization in solar flares. Here we study the microphysics of such perpendicular, low Mach number collisionless shocks using two-dimensional particle-in-cell (PIC) simulations with a reduced ion/electron mass ratio and employ a moving wall boundary method for initial generation of the shock. This moving wall method allows for more control of the shock speed, smaller simulation box sizes, and longer simulation times than the commonly used fixed wall, reflection method of shock formation. Our results, which are independent of the shock formation method, reveal the prevalence shock drift acceleration (SDA) of both electron and ions in a purely perpendicular shock with Alfv\\'en Mach number $M_A=6.8$ and ratio of thermal to magnetic pressure $\\beta=8$. We determine the respective minimum energies required for electrons and ...

  1. Paris vs. Prague: A "Suspicion of Fraud": Ernst Mach Argues over Photographs and Epistemological Prerequisites.

    Science.gov (United States)

    Hoffmann, Christoph

    2016-12-01

    Argument In spring 1888, an anonymous critic raised severe doubts about Ernst Mach's and Peter Salcher's studies, published one year before, on the processes in the air caused by very rapid projectiles. Paraphrasing the experiments for the French popular science magazine La Nature, the critic insinuated that the photographs upon which Mach and Salcher's argument were ostensibly based must have been of such low quality that they did not allow any well-founded conclusion. The critic did not deny the phenomena Mach and Salcher had presented in their article; he denied that the photographs taken in the course of the experiments could permit any observation of the phenomena. I take the resulting quarrel as a window into the actors' ideas on the requirements of "good observations" and the role of technical devices in this case. In particular I enquire how the various arguments relate to Lorraine Daston's and Peter Galison's framing of photography as an emblem of "mechanical objectivity." We will see that in the case under debate, actors considered naked-eye observation, observation by telescope and photography mainly with regard to the challenges of the particular research object.

  2. A half-explicit, non-split projection method for low Mach number flows.

    Energy Technology Data Exchange (ETDEWEB)

    Pousin, Jerome G. (National Institute for Applied Sciences, France); Najm, Habib N.; Pebay, Philippe Pierre

    2004-02-01

    In the context of the direct numerical simulation of low MACH number reacting flows, the aim of this article is to propose a new approach based on the integration of the original differential algebraic (DAE) system of governing equations, without further differentiation. In order to do so, while preserving a possibility of easy parallelization, it is proposed to use a one-step index 2 DAE time-integrator, the Half Explicit Method (HEM). In this context, we recall why the low MACH number approximation belongs to the class of index 2 DAEs and discuss why the pressure can be associated with the constraint. We then focus on a fourth-order HEM scheme, and provide a formulation that makes its implementation more convenient. Practical details about the consistency of initial conditions are discussed, prior to focusing on the implicit solve involved in the method. The method is then evaluated using the Modified KAPS Problem, since it has some of the features of the low MACH number approximation. Numerical results are presented, confirming the above expectations. A brief summary of ongoing efforts is finally provided.

  3. Electro-optic metal-insulator-semiconductor-insulator-metal Mach-Zehnder plasmonic modulator

    Science.gov (United States)

    Thomas, Roney; Ikonic, Zoran; Kelsall, Robert W.

    2012-01-01

    The performance of a CMOS-compatible electro-optic Mach-Zehnder plasmonic modulator is investigated using electromagnetic and carrier transport simulations. Each arm of the Mach-Zehnder device comprises a metal-insulator-semiconductor-insulator-metal (MISIM) structure on a buried oxide substrate. Quantum mechanical effects at the oxide/semiconductor interfaces were considered in the calculation of electron density profiles across the structure, in order to determine the refractive index distribution and its dependence on applied bias. This information was used in finite element simulations of the electromagnetic modes within the MISIM structure in order to determine the Mach-Zehnder arm lengths required to achieve destructive interference and the corresponding propagation loss incurred by the device. Both inversion and accumulation mode devices were investigated, and the layer thicknesses and height were adjusted to optimise the device performance. A device loss of <8 dB is predicted for a MISIM structure with a 25 nm thick silicon layer, for which the device length is <3 μm, and <5 dB loss is predicted for the limiting case of a 5 nm thick silicon layer in a 1.2 μm long device: in both cases, the maximum operating voltage is 7.5 V.

  4. The Dynamics of Very High Alfvén Mach Number Shocks in Space Plasmas

    Science.gov (United States)

    Sundberg, Torbjörn; Burgess, David; Scholer, Manfred; Masters, Adam; Sulaiman, Ali H.

    2017-02-01

    Astrophysical shocks, such as planetary bow shocks or supernova remnant shocks, are often in the high or very-high Mach number regime, and the structure of such shocks is crucial for understanding particle acceleration and plasma heating, as well inherently interesting. Recent magnetic field observations at Saturn’s bow shock, for Alfvén Mach numbers greater than about 25, have provided evidence for periodic non-stationarity, although the details of the ion- and electron-scale processes remain unclear due to limited plasma data. High-resolution, multi-spacecraft data are available for the terrestrial bow shock, but here the very high Mach number regime is only attained on extremely rare occasions. Here we present magnetic field and particle data from three such quasi-perpendicular shock crossings observed by the four-spacecraft Cluster mission. Although both ion reflection and the shock profile are modulated at the upstream ion gyroperiod timescale, the dominant wave growth in the foot takes place at sub-proton length scales and is consistent with being driven by the ion Weibel instability. The observed large-scale behavior depends strongly on cross-scale coupling between ion and electron processes, with ion reflection never fully suppressed, and this suggests a model of the shock dynamics that is in conflict with previous models of non-stationarity. Thus, the observations offer insight into the conditions prevalent in many inaccessible astrophysical environments, and provide important constraints for acceleration processes at such shocks.

  5. Study on Shock Wave and Turbulent Boundary Layer Interactions in a Square Duct at Mach 2 and 4

    Institute of Scientific and Technical Information of China (English)

    Hiromu SUGIYAMA; Ryojiro MINATO; Kazuhide MIZOBATA; Akira TOJO; Yohei MUTO

    2006-01-01

    In this paper, the outline of the Mach 4 supersonic wind runnel for the investigation of the supersonic internal flows in ducts was firstly described. Secondly, the location, structure and characteristics of the Mach 2 and Mach 4 pseudo-shock waves in a square duct were investigated by color schlieren photographs and duct wall pressure fluctuation measurements. Finally, the wall shear stress distributions on the side, top and bottom walls of the square duct with the Mach 4 pseudo-shock wave were investigated qualitatively by the shear stress-sensitive liquid crystal visualization method. The side wall boundary layer separation region under the first shock is narrow near the top wall, while the side wall boundary layer separation region under the first shock is very wide near the bottom wall.

  6. Characteristics of the Mach Disk in the Underexpanded Jet in which the Back Pressure Continuously Changes with Time

    Institute of Scientific and Technical Information of China (English)

    T. Irie; T. Yasunobu; H. Kashimura; T. Setoguchi

    2003-01-01

    When the high-pressure gas is exhausted to the vacuum chamber from the nozzle, the underexpanded supersonic jet contained with the Mach disk is generally formed. The eventual purpose of this study is to clarify the unsteady phenomenon of the underexpanded free jet when the back pressure continuously changes with time. The characteristic of the Mach disk has been clarified in consideration of the diameter and position of it by the numerical analysis in this paper. The sonic jet of the exit Mach number Me=1 is assumed and the axisymmetric conservational equation is solved by the TVD method in the numerical calculation.The diameter and position of the Mach disk differs with the results of a steady jet and the influence on the continuously changing of the back pressure is evidenced from the comparison with the case of steady supersonic jet.

  7. Refractometric sensor based on all-fiber coaxial Michelson and Mach-Zehnder interferometers for ethanol detection in fuel

    Energy Technology Data Exchange (ETDEWEB)

    Mosquera, L; Osorio, Jonas H; Hayashi, Juliano G; Cordeiro, Cristiano M B, E-mail: lmosquera@uni.edu.pe [Instituto de Fisica ' Gleb Wataghin' , UNICAMP, Campinas - Sao Paulo (Brazil)

    2011-01-01

    A refractometric sensor based on mechanically induced interferometers formed with long period gratings is reported. It is also shown two different setups based on a Michelson and Mach-Zehnder interferometer and its application to measure ethanol concentration in gasoline.

  8. Refractometric sensor based on all-fiber coaxial Michelson and Mach-Zehnder interferometers for ethanol detection in fuel

    Science.gov (United States)

    Mosquera, L.; Osório, Jonas H.; Hayashi, Juliano G.; Cordeiro, Cristiano M. B.

    2011-01-01

    A refractometric sensor based on mechanically induced interferometers formed with long period gratings is reported. It is also shown two different setups based on a Michelson and Mach-Zender interferometer and its application to measure ethanol concentration in gasoline.

  9. A tabulation of pipe length to diameter ratios as a function of Mach number and pressure ratios for compressible flow

    Science.gov (United States)

    Dixon, G. V.; Barringer, S. R.; Gray, C. E.; Leatherman, A. D.

    1975-01-01

    Computer programs and resulting tabulations are presented of pipeline length-to-diameter ratios as a function of Mach number and pressure ratios for compressible flow. The tabulations are applicable to air, nitrogen, oxygen, and hydrogen for compressible isothermal flow with friction and compressible adiabatic flow with friction. Also included are equations for the determination of weight flow. The tabulations presented cover a wider range of Mach numbers for choked, adiabatic flow than available from commonly used engineering literature. Additional information presented, but which is not available from this literature, is unchoked, adiabatic flow over a wide range of Mach numbers, and choked and unchoked, isothermal flow for a wide range of Mach numbers.

  10. Design of a fast boot method of VxWorks embedded system based on NOR Flash%一种基于Flash的VxWorks操作系统快速引导方法设计

    Institute of Scientific and Technical Information of China (English)

    肖二宁; 张兴明; 李晗; 魏帅

    2016-01-01

    Pointing to the condition that the embedded system is lack of NVRAM and the write& read speed request is not strict,a fast boot method of operation system based on Flash is designed on the platform of Vxworks operating system,the method uses NOR Flash storage for taking place of NVRAM to store boot information,and a 1+1 fault-tolerant mechanism is used. The test results show that it realizes the fast boot of operation system,and can effectively reduce the erase frequency, extend the service life of Flash,improves the system stability.%针对在嵌入式系统中缺少NVRAM并对读写速度要求不是很高的情况下,以VxWorks操作系统Workbench3.1为平台,设计了一种基于Flash的VxWorks操作系统快速引导方法,该方法通过用NOR Flash存储器代替NVRAM保存引导信息,并运用了1+1容错机制,经验证,该方法实现了VxWorks操作系统的快速引导,并有效降低了Flash的擦除频率,延长了Flash寿命,提高了系统的稳定性。

  11. High Accuracy Microwave Frequency Measurement Based on Single-Drive Dual-Parallel Mach-Zehnder Modulator

    DEFF Research Database (Denmark)

    Zhao, Ying; Deng, Lei; Pang, Xiaodan

    2011-01-01

    A novel approach for broadband microwave frequency measurement based on bias manipulation of a dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. A 10-3 relative error verifies a significant accuracy improvement by this method.......A novel approach for broadband microwave frequency measurement based on bias manipulation of a dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. A 10-3 relative error verifies a significant accuracy improvement by this method....

  12. Genome Sequencing

    DEFF Research Database (Denmark)

    Sato, Shusei; Andersen, Stig Uggerhøj

    2014-01-01

    The current Lotus japonicus reference genome sequence is based on a hybrid assembly of Sanger TAC/BAC, Sanger shotgun and Illumina shotgun sequencing data generated from the Miyakojima-MG20 accession. It covers nearly all expressed L. japonicus genes and has been annotated mainly based on transcr......The current Lotus japonicus reference genome sequence is based on a hybrid assembly of Sanger TAC/BAC, Sanger shotgun and Illumina shotgun sequencing data generated from the Miyakojima-MG20 accession. It covers nearly all expressed L. japonicus genes and has been annotated mainly based...

  13. 高腰鞋整前帮样板制取与修正%Development and Amendment on the Whole Vamp Pattern for Ankle Boot

    Institute of Scientific and Technical Information of China (English)

    刘虹秀; 孙继锋; 高海燕

    2013-01-01

    以整前帮高腰鞋样板制取与修正为例,重点介绍了帮样柱面设计中确定前脸点长、口门点、鞋舌及前帮线的方法,并依据展平原理,举例说明了5种实用的整前帮取样方法.此外,还简要分析了样板制取过程中经常出现的问题,并提出了解决方法.%The determining method of facing top point, vamp point, tongue line and quarter upper line are introduced with an example of pattern making and correction for ankle boots design. More, five practical methods of whole vamp spring is provided to illustrate our points according to the principle of flattening. In addition, common problems which are found in pattern making process, are briefly analyzed and the correlated solving methods are put forward.

  14. The LBT Bootes Field Survey: I. The Rest-frame UV and Luminosity Functions and Clustering of Bright Lyman Break Galaxies at z~3

    CERN Document Server

    Bian, Fuyan; Jiang, Linhua; McGreer, Ian; Dey, Arjun; Green, Richard; Maiolino, Roberto; Walter, Fabian; Lee, Kyoung-Soo; Dave, Romeel

    2013-01-01

    We present a deep LBT/LBC U-band imaging survey (9 deg2) covering the NOAO Bootes field. A total of 14,485 Lyman Break Galaxies (LBGs) at z~3 are selected, which are used to measure the rest-frame UV luminosity function (LF). The large sample size and survey area reduce the LF uncertainties due to Poisson statistics and cosmic variance by >3 compared to previous studies. At the bright end, the LF shows excess power compared to the best-fit Schechter function, which can be attributed to the contribution of $z\\sim3$ quasars. We compute the rest-frame near-infrared LF and stellar mass function (SMF) of z~3 LBGs based on the R-band and IRAC [4.5 micro m]-band flux relation. We investigate the evolution of the UV LFs and SMFs between z~7 and z~3, which supports a rising star formation history in the LBGs. We study the spatial correlation function of two bright LBG samples and estimate their average host halo mass. We find a tight relation between the host halo mass and the galaxy star formation rate (SFR),which fo...

  15. Research and Practice on DOS Boot Recorder Recovery of NTFS File System%NTFS文件系统的DBR恢复研究与实践

    Institute of Scientific and Technical Information of China (English)

    蒋笑天; 匡芳君

    2013-01-01

    N T FS文件系统的DBR扇区存储着文件系统的重要信息,由于病毒、断电、误操作等各种原因引起DBR损坏,出现未格式化现象。通过分析N T FS文件系统结构,提出了一种通过寻找M FT 表和计算DBR中BPB重要参数的方法,利用磁盘编辑工具WinHex对NTFS文件系统的DBR信息损坏进行恢复实践,实践证明该方法可行。%DOS boot recorder of NTFS file system stores much important information .DBR may be damaged by various reasons such as viruses ,power outages ,wrong operation ,etc .The partition will appear unformatted phenomenon .By an-alyzing the structure of NTFS file system ,the paper puts forward a method to rebuild DBR by looking for MFT table and calculation important parameters of BPB on DBR .Disk editing tools WinHex is used to recover DBR ,the practice has proved that the method is feasible .

  16. LOFAR low-band antenna observations of the 3C295 and Bootes fields: source counts and ultra-steep spectrum sources

    CERN Document Server

    van Weeren, R J; Tasse, C; Rottgering, H J A; Rafferty, D A; van der Tol, S; Heald, G; White, G J; Shulevski, A; Best, P; Intema, H T; Bhatnagar, S; Reich, W; Steinmetz, M; van Velzen, S; Ensslin, T A; Prandoni, I; de Gasperin, F; Jamrozy, M; Brunetti, G; Jarvis, M J; McKean, J P; Wise, M W; Ferrari, C; Harwood, J; Oonk, J B R; Hoeft, M; Kunert-Bajraszewska, M; Horellou, C; Wucknitz, O; Bonafede, A; Mohan, N R; Scaife, A M M; Klockner, H -R; van Bemmel, I M; Merloni, A; Chyzy, K T; Engels, D; Falcke, H; Pandey-Pommier, M; Alexov, A; Anderson, J; Avruch, I M; Beck, R; Bell, M E; Bentum, M J; Bernardi, G; Breitling, F; Broderick, J; Brouw, W N; Bruggen, M; Butcher, H R; Ciardi, B; de Geus, E; de Vos, M; Deller, A; Duscha, S; Eisloffel, J; Fallows, R A; Frieswijk, W; Garrett, M A; Griessmeier, J; Gunst, A W; Hamaker, J P; Hassall, T E; Horandel, J; van der Horst, A; Iacobelli, M; Jackson, N J; Juette, E; Kondratiev, V I; Kuniyoshi, M; Maat, P; Mann, G; McKay-Bukowski, D; Mevius, M; Morganti, R; Munk, H; Offringa, A R; Orru, E; Paas, H; Pandey, V N; Pietka, G; Pizzo, R; Polatidis, A G; Renting, A; Rowlinson, A; Schwarz, D; Serylak, M; Sluman, J; Smirnov, O; Stappers, B W; Stewart, A; Swinbank, J; Tagger, M; Tang, Y; Thoudam, S; Toribio, C; Vermeulen, R; Vocks, C; Zarka, P

    2014-01-01

    We present LOFAR Low Band observations of the Bootes and 3C295 fields. Our images made at 34, 46, and 62 MHz reach noise levels of 12, 8, and 5 mJy beam$^{-1}$, making them the deepest images ever obtained in this frequency range. In total, we detect between 300 and 400 sources in each of these images, covering an area of 17 to 52 deg$^{2}$. From the observations we derive Euclidean-normalized differential source counts. The 62 MHz source counts agree with previous GMRT 153 MHz and VLA 74 MHz differential source counts, scaling with a spectral index of $-0.7$. We find that a spectral index scaling of $-0.5$ is required to match up the LOFAR 34 MHz source counts. This result is also in agreement with source counts from the 38 MHz 8C survey, indicating that the average spectral index of radio sources flattens towards lower frequencies. We also find evidence for spectral flattening using the individual flux measurements of sources between 34 and 1400 MHz and by calculating the spectral index averaged over the so...

  17. Concept Development of a Mach 1.6 High-Speed Civil Transport

    Science.gov (United States)

    Shields, Elwood W.; Fenbert, James W.; Ozoroski, Lori P.; Geiselhart, Karl A.

    1999-01-01

    A high-speed civil transport configuration with a Mach number of 1.6 was developed as part of the NASA High-Speed Research Program to serve as a baseline for assessing advanced technologies required for an aircraft with a service entry date of 2005. This configuration offered more favorable solutions to environmental concerns than configurations with higher Mach numbers. The Mach 1.6 configuration was designed for a 6500 n.mi. mission with a 250-passenger payload. The baseline configuration has a wing area of 8732 square feet a takeoff gross weight of 591570 lb, and four 41000-lb advanced turbine bypass engines defined by NASA. These engines have axisymmetric mixer-ejector nozzles that are assumed to yield 20 dB of noise suppression during takeoff, which is assumed to satisfy, the FAR Stage III noise requirements. Any substantial reduction in this assumed level of suppression would require oversizing the engines to meet community noise regulations and would severly impact the gross weight of the aircraft at takeoff. These engines yield a ratio of takeoff thrust to weight of 0.277 and a takeoff wing loading of 67.8 lb/square feet that results in a rotation speed of 169 knots. The approach velocity of the sized configuration at the end of the mission is 131 knots. The baseline configuration was resized with an engine having a projected life of 9000 hr for hot rotating parts and 18000 hr for the rest of the engine, as required for commercial use on an aircraft with a service entry date of 2005. Results show an increase in vehicle takeoff gross weight of approximately 58700 lb. This report presents the details of the configuration development, mass properties, aerodynamic design, propulsion system and integration, mission performance, and sizing.

  18. Tunable multiwavelength erbium-doped fiber laser based on an in-line Mach Zehnder interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Han, Young-Geun [Hanyang University, Seoul (Korea, Republic of)

    2010-12-15

    A tunable multiwavelength erbium-doped fiber laser based on an in-line Mach Zehnder interferometer is proposed and experimentally demonstrated. The in-line Mach Zehnder interferometer is realized by using cascaded long-period fiber gratings. The long-period fiber gratings can couple the guided core mode to several cladding modes. If two identical long-period fiber gratings are concatenated, an interference pattern can be generated, which results from an interaction of the core and the cladding modes in the second long-period fiber grating. Therefore, a simple multichannel filter based on an in-line Mach Zehnder interferometer can be realized. The wavelength spacing of the proposed multichannel filter is controlled by the number of long-period fiber gratings. We apply the proposed multichannel fiber to the generation of a multiwavelength erbium-doped fiber laser with a tunability on the order of the wavelength spacing. An erbium-doped fiber amplifier is implemented as a gain medium. The gain competition of erbium ions is suppressed by soaking the erbium-doped fiber in liquid nitrogen. The power fluctuation of the proposed multiwavelength fiber laser is measured to be less than 0.5 dB. A high-quality multiwavelength output with a high extinction ratio of more than 40 dB is achieved. The wavelength spacing of the proposed multiwavelength fiber laser is controlled by increasing the number of long-period fiber gratings. The wavelength spacing is changed from 0.8 nm to 1.6 nm discretely.

  19. Effects of nonuniform Mach-number entrance on scramjet nozzle flowfield and performance

    Science.gov (United States)

    Zhang, Pu; Xu, Jinglei; Quan, Zhibin; Mo, Jianwei

    2016-12-01

    Considering the non-uniformities of nozzle entrance influenced by the upstream, the effects of nonuniform Mach-number coupled with shock and expansion-wave on the flowfield and performances of single expansion ramp nozzle (SERN) are numerically studied using Reynolds-Averaged Navier-Stokes equations. The adopted Reynolds-averaged Navier-Stokes methodology is validated by comparing the numerical results with the cold experimental data, and the average method used in this paper is discussed. Uniform and nonuniform facility nozzles are designed to generate different Mach-number profile for the inlet of SERN, which is direct-connected with different facility nozzle, and the whole flowfield is simulated. Because of the coupling of shock and expansion-wave, flow direction of nonuniform SERN entrance is distorted. Compared with Mach contour of uniform case, the line is more curved for coupling shock-wave entrance (SWE) case, and flatter for the coupling expansion-wave entrance (EWE) case. Wall pressure distribution of SWE case appears rising region, whereas decreases like stairs of EWE case. The numerical results reveal that the coupled shock and expansion-wave play significant roles on nozzle performances. Compared with the SERN performances of uniform entrance case at the same work conditions, the thrust of nonuniform entrance cases reduces by 3-6%, pitch moment decreases by 2.5-7%. The negative lift presents an incremental trend with EWE while the situation is the opposite with SWE. These results confirm that considering the entrance flow parameter nonuniformities of a scramjet nozzle coupled with shock or expansion-wave from the upstream is necessary.

  20. Dna Sequencing

    Science.gov (United States)

    Tabor, Stanley; Richardson, Charles C.

    1995-04-25

    A method for sequencing a strand of DNA, including the steps off: providing the strand of DNA; annealing the strand with a primer able to hybridize to the strand to give an annealed mixture; incubating the mixture with four deoxyribonucleoside triphosphates, a DNA polymerase, and at least three deoxyribonucleoside triphosphates in different amounts, under conditions in favoring primer extension to form nucleic acid fragments complementory to the DNA to be sequenced; labelling the nucleic and fragments; separating them and determining the position of the deoxyribonucleoside triphosphates by differences in the intensity of the labels, thereby to determine the DNA sequence.

  1. Using a Mach-Zehnder interferometer to deduce nitrogen density mapping

    Science.gov (United States)

    Boudaoud, F.; Lemerini, M.

    2015-07-01

    This work presents an optical method using the Mach-Zehnder interferometer. We especially diagnose a pure nitrogen gas subjected to a point to plane corona discharge, and visualize the density spatial map. The interelectrode distance equals 6 mm and the variation of the optical path has been measured at different pressures: 220 Torr, 400 Torr, and 760 Torr. The interferograms are recorded with a CCD camera, and the numerical analysis of these interferograms is assured by the inverse Abel transformation. The nitrogen density is extracted through the Gladstone-Dale relation. The obtained results are in close agreement with values available in the literature.

  2. A Novel Method to Monitor OSNR Using a Mach-Zehnder Interferometer

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel method to monitor optical signal to noise ratio using a Mach-Zehnder interferometer is introduced. The OSNR meter is composed of two 3dB couplers, one phase tuner and one power meter which are of low cost. The experiments show that the error of our novel method is less than 0.5dB and the dynamic range is from 10dB to 25dB. They also show that the method works well under different cases of bit rates.

  3. Thermal management for a Mach 5 cruise aircraft using endothermic fuel

    Science.gov (United States)

    Petley, Dennis H.; Jones, Stuart C.

    1990-01-01

    The present thermal management system for a carrier-based Mach 5 cruise-capable aircraft whose propulsion system does not entail cryogenic fuels is predicated on the use of the catalytic endothermic reaction of a petroleum-derived hydrocarbon fuel as the heat sink for engine cooling. The insulation of engine flowpath surfaces reduces cooling requirements. The primary elements of this closed-cycle cooling system are a fuel preheater, a catalytic fuel reactor, and engine wall-cooling panels; a silicone-based liquid polymer is used as the coolant. Structural, weight, and thermal analysis results are presented for each of the primary components.

  4. Lateral-shearing, delay-dithering Mach-Zehnder interferometer for spatial coherence measurement.

    Science.gov (United States)

    Efimov, Anatoly

    2013-11-15

    An image-shearing interferometer of Mach-Zehnder type with corner cubes is introduced for the purpose of measuring spatial coherence at the output of inhomogeneous optical sources, such as multimode fibers (MMFs). One arm of the interferometer is modulated in optical delay to produce dynamic interference fringes. Fringe visibility and the two individual intensities are measured nearly simultaneously to allow direct calculation of the modulus of the complex degree of coherence as a function of the lateral shear between the two interferometer arms. Spatial degree of coherence is measured for a step-index MMF pumped with monochromatic and broadband optical sources.

  5. Transition to Double Mach Stem for Nuclear Explosion at 104 ft Height of Burst.

    Science.gov (United States)

    1981-11-17

    intersecting the ground. The initialization provides a strong shock with Mach number MI = 12. This speed and the need for restart capability led to the choice...a HOB of 104 ft (31.7m). A strong spherical shock is created in the surrounding air, and’ reflects from the grcund. 9 The outward-traveling airbiast...AIR FCIPCF SYST T’M CCvfvtANC NORTON" A!7, CA 9?40Pg (MIIJ’r’-MAN) QICY ATTN "INNYH "D IALAN5S<Y 0O1C Y ATTNJ MMN)) eHM kF-LVECCHir OICY ATTN fuNN w

  6. Developing an Interactive Tutorial on a Mach-Zehnder Interferometer with Single Photons

    CERN Document Server

    Singh, Chandralekha

    2015-01-01

    We are developing a Quantum Interactive Learning Tutorial (QuILT) on a Mach-Zehnder Interferometer with single photons to expose upper-level students in quantum mechanics courses to contemporary applications. The QuILT strives to help students develop the ability to apply fundamental quantum principles to physical situations and explore differences between classical and quantum ideas. The QuILT adapts visualization tools to help students build physical intuition about quantum phenomena and focuses on helping them integrate qualitative and quantitative understanding. We also discuss findings from a preliminary in-class evaluation.

  7. Linearization of Mach-Zehnder modulator using microring-based all-pass filter

    Institute of Scientific and Technical Information of China (English)

    Jianyi Yang; Fan Wang; Xiaoqing Jiang; Hongchang Qu; Yaming Wu; Minghua Wang; Yuelin Wang

    2005-01-01

    @@ By applying the microring resonator to the Mach-Zehnder (MZ) optical modulator and employing the super-linear phase change characteristic of the all-pass filter, the sublinear modulation curve of the conventional MZ modulator is highly linearized. With properly controlled power coupling between the microring and the arm of the MZ modulator, the third-order distortion can be suppressed. If the transmission coefficient is set between 0.25 and 0.42, the linearity range larger than 90% can be easily achieved. The maximum linearity range is even up to 99.5%.

  8. Integrated optical displacement sensor based on asymmetric Mach-Zehnder interferometer chip

    Science.gov (United States)

    Zhao, Ning; Qian, Guang; Fu, Xing-Chang; Zhang, Li-Jiang; Hu, Wei; Li, Ruo-Zhou; Zhang, Tong

    2017-02-01

    Displacement sensor is one of the most important measuring instruments in many automated systems. We demonstrated an integrated optical displacement sensor based on an asymmetric Mach-Zehnder interferometer chip on a flexible substrate. The sensing chip was made of polymer materials and fabricated by lithography and lift-off techniques. Measured results show that the device has a loss of less than 5 dB and a potential sensitivity of about 0.105 rad/μm with quite a large space for promotion. The sensor has advantages of antielectromagnetic interference, high reliability and stability, simple preparing process, and low cost; it will occupy an important place in displacement sensors.

  9. Mach Number Dependence of Turbulent Magnetic Field Amplification: Solenoidal versus Compressive Flows

    CERN Document Server

    Federrath, Christoph; Schober, Jennifer; Banerjee, Robi; Klessen, Ralf S; Schleicher, Dominik R G; 10.1103/PhysRevLett.107.114504

    2011-01-01

    We study the growth rate and saturation level of the turbulent dynamo in magnetohydrodynamical simulations of turbulence, driven with solenoidal (divergence-free) or compressive (curl-free) forcing. For models with Mach numbers ranging from 0.02 to 20, we find significantly different magnetic field geometries, amplification rates, and saturation levels, decreasing strongly at the transition from subsonic to supersonic flows, due to the development of shocks. Both extreme types of turbulent forcing drive the dynamo, but solenoidal forcing is more efficient, because it produces more vorticity.

  10. Efficient thermo-optically controlled Mach-Zhender interferometers using dielectric-loaded plasmonic waveguides

    DEFF Research Database (Denmark)

    Gosciniak, J.; Markey, L.; Dereux, A.;

    2012-01-01

    Compact fiber-coupled dielectric-loaded plasmonic Mach-Zehnder interferometers operating at telecom wavelengths and controlled via the thermo-optic effect are reported. Two fabricated structures with Cytop substrate and a ridge made of PMMA or a cycloaliphatic acrylate polymer (CAP) were considered...... showing low switching power of 2.35 mW and switching time in the range of microseconds for a CAP ridge and milliseconds switching time for a PMMA ridge. Full output modulation is demonstrated for the structure with a CAP ridge and 40% modulation with a PMMA ridge. (C) 2012 Optical Society of America...

  11. The Experimental Measurement of Aerodynamic Heating About Complex Shapes at Supersonic Mach Numbers

    Science.gov (United States)

    Neumann, Richard D.; Freeman, Delma C.

    2011-01-01

    In 2008 a wind tunnel test program was implemented to update the experimental data available for predicting protuberance heating at supersonic Mach numbers. For this test the Langley Unitary Wind Tunnel was also used. The significant differences for this current test were the advances in the state-of-the-art in model design, fabrication techniques, instrumentation and data acquisition capabilities. This current paper provides a focused discussion of the results of an in depth analysis of unique measurements of recovery temperature obtained during the test.

  12. Asymmetric Mach-Zehnder Interferometer Based Biosensors for Aflatoxin M1 Detection.

    Science.gov (United States)

    Chalyan, Tatevik; Guider, Romain; Pasquardini, Laura; Zanetti, Manuela; Falke, Floris; Schreuder, Erik; Heideman, Rene G; Pederzolli, Cecilia; Pavesi, Lorenzo

    2016-01-06

    In this work, we present a study of Aflatoxin M1 detection by photonic biosensors based on Si₃N₄ Asymmetric Mach-Zehnder Interferometer (aMZI) functionalized with antibodies fragments (Fab'). We measured a best volumetric sensitivity of 10⁴ rad/RIU, leading to a Limit of Detection below 5 × 10(-7) RIU. On sensors functionalized with Fab', we performed specific and non-specific sensing measurements at various toxin concentrations. Reproducibility of the measurements and re-usability of the sensor were also investigated.

  13. Low Mach and Peclet number limit for a model of stellar tachocline and upper radiative zones

    Directory of Open Access Journals (Sweden)

    Donatella Donatelli

    2016-09-01

    Full Text Available We study a hydrodynamical model describing the motion of internal stellar layers based on compressible Navier-Stokes-Fourier-Poisson system. We suppose that the medium is electrically charged, we include energy exchanges through radiative transfer and we assume that the system is rotating. We analyze the singular limit of this system when the Mach number, the Alfven number, the Peclet number and the Froude number approache zero in a certain way and prove convergence to a 3D incompressible MHD system with a stationary linear transport equation for transport of radiation intensity. Finally, we show that the energy equation reduces to a steady equation for the temperature corrector.

  14. Planar Rayleigh scattering results in helium-air mixing experiments in a Mach-6 wind tunnel

    Science.gov (United States)

    Shirinzadeh, B.; Hillard, M. E.; Balla, R. J.; Waitz, I. A.; Anders, J. B.; Exton, R. J.

    1992-01-01

    Planar Rayleigh scattering measurements with an argon-fluoride excimer laser are performed to investigate helium mixing into air at supersonic speeds. The capability of the Rayleigh scattering technique for flow visualization of a turbulent environment is demonstrated in a large-scale, Mach-6 facility. The detection limit obtained with the present setup indicates that planar, quantitative measurements of density can be made over a large cross-sectional area (5 cm x 10 cm) of the flow field in the absence of clusters.

  15. Study of Rayleigh scattering for visualization of helium-air mixing at Mach 6

    Science.gov (United States)

    Shirinzadeh, B.; Balla, R. J.; Hillard, M. E.; Anders, J. B.; Exton, R. J.; Waitz, I. A.

    1991-01-01

    Using an ArF excimer laser, planar Rayleigh scattering measurements were performed to investigate helium mixing into air at supersonic speeds. These experiments were conducted in the Mach 6, high-Reynolds-number facility at NASA Langley Research Center. The capability of the Rayleigh scattering technique for flow visualization of a turbulent environment was demonstrated. The qualitative agreement between the averaged Rayleigh results and the reduced mean-mass-densities obtained from probe measurements substantiate that careful application of the technique, even in the presence of clusters, can give very useful results. It was also demonstrated that planar, quantitative measurements can be made in the absence of clusters.

  16. Planar Rayleigh Scattering Results in Helium/Air Mixing Experiments in a Mach 6 Wind Tunnel

    Science.gov (United States)

    Shirinzadeh, B.; Balla, R. Jeffrey; Hillard, M. E.; Anders, J. B.; Exton, R. J.; Waitz, I. A.

    1991-01-01

    Planar Rayleigh scattering measurements using an ArF-excimer laser have been performed to investigate helium mixing into air at supersonic speeds. The capability of the Rayleigh scattering technique for flow visualization of a turbulent environment is demonstrated in a large-scale, Mach 6facility. The detection limit obtained with the present setup indicates that planar, quantitative measurements of density can be made over a large cross sectional area (5 cm by 10 cm) of the flow field in the absence of clusters.

  17. Theoretical Analysis and Experiment of Temperature Stability for Fiber-optic Mach-Zehnder Interferometer Filter

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Fiber-optic Mach-Zehnder interferometer(MZI) can be used as wavelength-multiplexers and demultiplexers. The △L and △φ directly influence the properties of MZI. To lengthen the △L can demultiplex much more wavelengths, but when the △L is longer, the temperature will influence MZI more seriously. A method to solve this problem is proposed, which enables MZI to work stably. The wavelength distance is 0.8nm, and the extinction ratio is high.

  18. Analisis Perbandingan Kinerja Mach-Zehnder berdasarkan Ragam Format Modulasi pada Jaringan FTTH

    Directory of Open Access Journals (Sweden)

    ZULIA NURUL KARIMAH

    2017-01-01

    Full Text Available ABSTRAKPada jurnal ini dibuat pemodelan link FTTH pada software Optisystem 7.0 untuk mengetahui pengaruh dari Kerr effect dengan membandingkan performansi serat optik kaca dan serat optik plastik berdasarkan format modulasi berupa NRZ, RZ, RZ-DPSK, RZ-DQPSK dan CSRZ. Terdapat dua skenario, dengan skenario pertama, variabel input yang diubah adalah format modulasi pada Mach-zehnder, sedangkan pada skenario kedua, variabel yang diubah adalah pemakaian serat optik yang dipakai, yaitu serat optik bahan kaca, plastik dan hybrid kaca plastik. Hasil simulasi menunjukkan dengan efek linier dan non-linier pada kabel kaca yang menghasilkan performansi jaringan dari yang terbaik, dengan Q factor di atas 6 dan BER di bawah 10-9 adalah NRZ, RZ, RZ-DPSK, CSRZ dan RZ-DQPSK. Sedangkan dengan penggunaan kabel PMMA, yang menunjukkan performansi jaringan yang baik adalah dengan konfigurasi G652D-G652D-PMMA pada format modulasi NRZ, RZ, RZ-DPSK dan RZ-DQPSK. Efek non-linier yang terjadi pada jaringan ini hanya SPM dan XPM.Kata kunci: FTTH, mach-zehnder, format modulasi, efek non-linier, GOF, POF.ABSTRACTIn this journal is creating a FTTH link on Optisystem software 7.0 to determine the effect of Kerr effect by comparing the performance of fiber optic glass and plastic optical fiber based on modulation formats such as NRZ, RZ, RZ-DPSK, RZ-DQPSK and CSRZ. There are two scenarios, first, input variables are changed based on format in Mach-zehnder modulator, while in the second scenario, the changed variable is the material of optical fiber, the materials are optical fiber glass, plastic and hybrid plastic and glass. The simulation results based on comparison with linear and nonlinear effects on glass optical fiber, which produce Q factor above 6 and BER below 10-9 are NRZ, RZ, RZ-DPSK, CSRZ and RZ-DQPSK. While the use of PMMA cable, which indicates good network performance is the configuration G652D-G652D-PMMA on the modulation format NRZ, RZ, RZ-DPSK and RZ

  19. Vibration sensing using a tapered bend-insensitive fiber based Mach-Zehnder interferometer.

    Science.gov (United States)

    Xu, Yanping; Lu, Ping; Qin, Zengguang; Harris, Jeremie; Baset, Farhana; Lu, Ping; Bhardwaj, Vedula Ravi; Bao, Xiaoyi

    2013-02-11

    In this study, a novel fiber-optic sensor consisting of a tapered bend-insensitive fiber based Mach-Zehnder interferometer is presented to realize damped and continuous vibration measurement. The double cladding structure and the central coating region of the in-fiber interferometer ensure an enhanced mechanical strength, reduced external disturbance, and a more uniform spectrum. A damped vibration frequency range of 29-60 Hz as well as continuous vibration disturbances ranging from 1 Hz up to 500 kHz are successfully demonstrated.

  20. Opacity Broadening of $^{13}$CO Linewidths and its Effect on the Variance-Sonic Mach Number Relation

    CERN Document Server

    Correia, Caio; Lazarian, Alex; Ossenkopf, Volker; Stutzki, Jürgen; Kainulainen, Jouni; Kowal, Grzegorz; de Medeiros, José Renan

    2014-01-01

    We study how the estimation of the sonic Mach number ($M_s$) from $^{13}$CO linewidths relates to the actual 3D sonic Mach number. For this purpose we analyze MHD simulations which include post-processing to take radiative transfer effects into account. As expected, we find very good agreement between the linewidth estimated sonic Mach number and the actual sonic Mach number of the simulations for optically thin tracers. However, we find that opacity broadening causes $M_s$ to be overestimated by a factor of ~ 1.16 - 1.3 when calculated from optically thick $^{13}$CO lines. We also find that there is a dependency on the magnetic field: super-Alfv\\'enic turbulence shows increased line broadening as compared with sub-Alfv\\'enic turbulence for all values of optical depth for supersonic turbulence. Our results have implications for the observationally derived sonic Mach number--density standard deviation ($\\sigma_{\\rho/}$) relationship, $\\sigma^2_{\\rho/}=b^2M_s^2$, and the related column density standard deviatio...

  1. Parametric investigation of single-expansion-ramp nozzles at Mach numbers from 0.60 to 1.20

    Science.gov (United States)

    Capone, Francis J.; Re, Richard J.; Bare, E. Ann

    1992-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the effects of varying six nozzle geometric parameters on the internal and aeropropulsive performance characteristics of single-expansion-ramp nozzles. This investigation was conducted at Mach numbers from 0.60 to 1.20, nozzle pressure ratios from 1.5 to 12, and angles of attack of 0 deg +/- 6 deg. Maximum aeropropulsive performance at a particular Mach number was highly dependent on the operating nozzle pressure ratio. For example, as the nozzle upper ramp length or angle increased, some nozzles had higher performance at a Mach number of 0.90 because of the nozzle design pressure was the same as the operating pressure ratio. Thus, selection of the various nozzle geometric parameters should be based on the mission requirements of the aircraft. A combination of large upper ramp and large lower flap boattail angles produced greater nozzle drag coefficients at Mach number greater than 0.80, primarily from shock-induced separation on the lower flap of the nozzle. A static conditions, the convergent nozzle had high and nearly constant values of resultant thrust ratio over the entire range of nozzle pressure ratios tested. However, these nozzles had much lower aeropropulsive performance than the convergent-divergent nozzle at Mach number greater than 0.60.

  2. Specularly reflected He sup 2+ at high Mach number quasi-parallel shocks

    Energy Technology Data Exchange (ETDEWEB)

    Fuselier, S.A.; Lennartsson, O.W. (Lockheed Palo Alto Research Lab., CA (United States)); Thomsen, M.F. (Los Alamos National Lab., NM (United States)); Russell, C.T. (Univ. of California, Los Angeles (United States))

    1990-04-01

    Upstream from the Earth's quasi-parallel bow shock, the Lockheed Plasma Composition Experiment on ISEE 1 often observes two types of suprathermal He{sup 2+} distributions. Always present to some degree is an energetic (several keV/eto 17.4 keV/e, the maximum energy of the detector) diffuse He{sup 2+} distribution. Sometimes, apparently when the Alfven Mach number, M{sub A}, is high enough and the spacecraft is near the shock (within a few minutes of a crossing), a second type of suprathermal He{sup 2+} distribution is also observed. This nongyrotropic, gyrating He{sup 2+} distribution has velocity components parallel and perpendicular to the magnetic field that are consistent with near-specular reflection of a portion of the incident solar wind He{sup 2+} distribution off the shock. Specularly reflected and diffuse proton distributions are associated with these gyrating He{sup 2+} distributions. The presence of these gyrating He{sup 2+} distributions suggests that specular reflection is controlled primarily by magnetic forces in high Mach number quasi-parallel shocks and that these distributions may be a seed population for more energetic diffuse He{sup 2+} distributions.

  3. A Detailed Investigation of Staged Normal Injection into a Mach 2 Flow

    Science.gov (United States)

    Eklund, Dean R.; Northam, G. Burton; Hartfield, Roy J., Jr.

    1990-01-01

    A study of the staged injection of two jets of air behind a rearward facing step into a Mach 2 flow was performed using the SPARK 3-D Navier-Stokes code. Calculated mole fraction distributions were compared with an extensive set of planar mole fraction measurements made with a laser induced iodine fluorescence technique. A statistical measure, the standard deviation, was used to help assess agreement between calculation and experiment. Overall, good agreement was found between calculated and measured values. Generally, agreement was better in the far field of the injectors. The effect of grid resolution was investigated by calculating solutions on grids of 60,000, 200,000, and 450,000 points. Differences in the solutions on the two finer grids were small. However, the mole fraction distributions were distinguishable. The effect of turbulence modeling was investigated by employing three different algebraic models for the jet turbulence: the Baldwin-Lomax model, the Prandtl mixing length model, and the Eggers mixing length model. Overall, the Eggers mixing length model was found to be superior for this case. Finally, the effect of the jet exit conditions was examined. A recently proposed Mach number distribution at the jet exit was found to slightly improve agreement between measurement and calculation.

  4. Concept Development of a Mach 2.4 High-Speed Civil Transport

    Science.gov (United States)

    Fenbert, James W.; Ozoroski, Lori P.; Geiselhart, Karl A.; Shields, Elwood W.; McElroy, Marcus O.

    1999-01-01

    In support of the NASA High-Speed Research Program, a Mach 2.4 high-speed civil transport concept was developed to serve as a baseline for studies to assess advanced technologies required for a feasible year 2005 entry-into-service vehicle. The configuration was designed to carry 251 passengers at Mach 2.4 cruise with a 6500-n.mi. range and operate in the existing world airport structure. The details of the configuration development, aerodynamic design, propulsion system and integration, mass properties, sizing, and mission performance are presented. The baseline configuration has a wing area of 9l00 sq ft and a takeoff gross weight of 614300 lb. The four advanced turbine bypass engines have 39 000 lb thrust with a weight of 9950 lb each, yielding a vehicle takeoff thrust-to-weight ratio of 0.254 and a takeoff wing loading of 67.5 lb/sq ft. The configuration was sized by the 11000-ft takeoff field length requirement and the usable fuel volume limit, which results in a rotation speed of 179 knots and an end-of-mission landing approach velocity of 134 knots.

  5. Concept development of a Mach 4 high-speed civil transport

    Science.gov (United States)

    Domack, Christopher S.; Dollyhigh, Samuel M.; Beissner, Fred L., Jr.; Geiselhart, Karl A.; Mcgraw, Marvin E., Jr.; Shields, Elwood W.; Swanson, Edward E.

    1990-01-01

    A study was conducted to configure and analyze a 250 passenger, Mach 4 High Speed Civil Transport with a design range of 6500 n.mi. The design mission assumed an all-supersonic cruise segment and no community noise or sonic boom constraints. The study airplane was developed in order to examine the technology requirements for such a vehicle and to provide an unconstrained baseline from which to assess changes in technology levels, sonic boom limits, or community noise constraints in future studies. The propulsion, structure, and materials technologies utilized in the sizing of the study aircraft were assumed to represent a technology availability date of 2015. The study airplane was a derivative of a previously developed Mach 3 concept and utilized advanced afterburning turbojet engines and passive airframe thermal protection. Details of the configuration development, aerodynamic design, propulsion system, mass properties, and mission performance are presented. The study airplane was estimated to weigh approx. 866,000 lbs. Although an aircraft of this size is a marginally acceptable candidate to fit into the world airport infrastructure, it was concluded that the inclusion of community noise or sonic boom constraints would quickly cause the aircraft to grow beyond acceptable limits using the assumed technology levels.

  6. Comparison of Staged Z-pinch Experiments at the NTF Zebra Facility with Mach2 simulations

    Science.gov (United States)

    Ruskov, E.; Wessel, F. J.; Rahman, H. U.; Ney, P.; Darling, T. W.; Johnson, Z.; McGee, E.; Covington, A.; Dutra, E.; Valenzuela, J. C.; Conti, F.; Narkis, J.; Beg, F.

    2016-10-01

    Staged Z-pinch experiments at the University of Nevada, Reno, 1MA Z-pinch Zebra facility were conducted. A hollow shell of argon gas liner is injected between 1 cm anode-cathode gap through a supersonic nozzle of 2.0 cm diameter with a throat gap of 240 microns. A deuterium plasma fill is injected inside the argon gas shell through a plasma gun as a fusible target plasma. An axial magnetic field is also applied throughout the pinch region. Experimental measurements such as pinch current, X-ray signal, neutron yield, and streak images are compared with MACH2 radiation hydrodynamic code simulations. The argon liner density profiles, obtained from the CFD (FLUENT), are used as an input to MACH2. The comparison suggests a fairly close agreement between the experimental measurements and the simulation results. This study not only helps to benchmark the code but also suggests the importance of the Z-pinch implosion time, optimizing both liner and target plasma density to obtain the maximum energy coupling between the circuit and the load. Advanced Research Projects Agency - Energy, DE-AR0000569.

  7. Variational modelling of extreme waves through oblique interaction of solitary waves: application to Mach reflection

    Science.gov (United States)

    Gidel, Floriane; Bokhove, Onno; Kalogirou, Anna

    2017-01-01

    In this work, we model extreme waves that occur due to Mach reflection through the intersection of two obliquely incident solitary waves. For a given range of incident angles and amplitudes, the Mach stem wave grows linearly in length and amplitude, reaching up to 4 times the amplitude of the incident waves. A variational approach is used to derive the bidirectional Benney-Luke equations, an asymptotic equivalent of the three-dimensional potential-flow equations modelling water waves. This nonlinear and weakly dispersive model has the advantage of allowing wave propagation in two horizontal directions, which is not the case with the unidirectional Kadomtsev-Petviashvili (KP) equation used in most previous studies. A variational Galerkin finite-element method is applied to solve the system numerically in Firedrake with a second-order Störmer-Verlet temporal integration scheme, in order to obtain stable simulations that conserve the overall mass and energy of the system. Using this approach, we are able to get close to the 4-fold amplitude amplification predicted by Miles.

  8. Mach Cones and Hydrodynamic Flow:. Probing Big Bang Matter in the Laboratory

    Science.gov (United States)

    Betz, Barbara; Rau, Philip; Stöcker, Horst

    A critical discussion of the present signals for the phase transition to quark-gluon plasma (QGP) is given. Since hadronic rescattering models predict much larger flow than observed from 1 to 50 A GeV laboratory bombarding energies, this observation is interpreted as potential evidence for a first-order phase transition at high baryon density. A detailed discussion of the collective flow as a barometer for the equation of state (EoS) of hot dense matter at RHIC follows. Here, hadronic rescattering models can explain 2 GeV/c. This is interpreted as an evidence for the production of superdense matter at RHIC. The connection of v2 to jet suppression is examined. A study of Mach shocks generated by fast partonic jets propagating through the QGP is given. The main goal is to take into account different types of collective motion during the formation and evolution of this matter. A significant deformation of Mach shocks in central Au+Au collisions at RHIC and LHC energies as compared to the case of jet propagation in a static medium is predicted. A new hydrodynamical study of jet energy loss is presented.

  9. The Contribution of Ernst Mach to Embodied Cognition and Mathematics Education

    Science.gov (United States)

    Zudini, Verena; Zuccheri, Luciana

    2016-08-01

    A study of the interactions between mathematics and cognitive science, carried out within a historical perspective, is important for a better understanding of mathematics education in the present. This is evident when analysing the contribution made by the epistemological theories of Ernst Mach. On the basis of such theories, a didactic method was developed, which was used in the teaching of mathematics in Austria at the beginning of the twentieth century and applied to different subjects ranging from simple operations in arithmetic to calculus. Besides the relevance of this method—also named the "Jacob method" after Josef Jacob who proposed it—to teaching practice, it could also be considered interesting in a wider context with reference to the mind-body problem. In particular, the importance that Jacob gives to "muscular activity" in the process of forming and elaborating mathematical concepts, derived from Mach, resounds in the current debate on embodied cognition, where cognitive processes are understood not as expressions of an abstract and merely computational mind but as based on our physicality as human beings, equipped not just with a brain but also a (whole) body. This model has been applied to mathematics in the "theory of embodied mathematics", the objective of which is to study, with the methods and apparatus of embodied cognitive science, the cognitive mechanisms used in the human creation and conceptualisation of mathematics. The present article shows that the "Jacob method" may be considered a historical example of didactical application of analogous ideas.

  10. Improved optical techniques for studying sonic and supersonic injection into Mach 3 flow

    Science.gov (United States)

    Buggele, Alvin E.; Seasholtz, Richard G.

    1997-11-01

    Filtered Rayleigh Scattering and shadowgraph flow visualization were used to characterize the penetration of helium or moist air injected transversely at several pressures to a Mach 3 flow in the NASA Lewis 3.81 inch by 10 inch continuous flow supersonic wind tunnel. This work is in support of the LOX augmented nuclear thermal rocket program. The present study used an injection-seeded, frequency doubled Nd:YAG pulsed laser to illuminate a transverse section of the injectant plume. Rayleigh scattered light was passed through an iodine absorption cell to suppress stray laser light and was imaged onto a cooled CCD camera. The scattering was based on condensation of water vapor in the injectant flow. Results are presented for various configurations of sonic and supersonic injector designs mounted primarily in the floor of the tunnel. Injectors studied include a single 0.25 inch diameter hole, five 0.112 inch diameter holes on 0.177 inch spacing, and a 7 degree half angle wedge. High speed shadowgraph flow visualization images were obtained with several video camera systems. Roof and floor static pressure data are presented several ways for the three configurations of injection designs with and without helium and/or air injection into Mach 3 flow.

  11. The influence of incident shock Mach number on radial incident shock wave focusing

    Directory of Open Access Journals (Sweden)

    Xin Chen

    2016-04-01

    Full Text Available Experiments and numerical simulations were carried out to investigate radial incident shock focusing on a test section where the planar incident shock wave was divided into two identical ones. A conventional shock tube was used to generate the planar shock. Incident shock Mach number of 1.51, 1.84 and 2.18 were tested. CCD camera was used to obtain the schlieren photos of the flow field. Third-order, three step strong-stability-preserving (SSP Runge-Kutta method, third-order weighed essential non-oscillation (WENO scheme and adaptive mesh refinement (AMR algorithm were adopted to simulate the complicated flow fields characterized by shock wave interaction. Good agreement between experimental and numerical results was observed. Complex shock wave configurations and interactions (such as shock reflection, shock-vortex interaction and shock focusing were observed in both the experiments and numerical results. Some new features were observed and discussed. The differences of structure of flow field and the variation trends of pressure were compared and analyzed under the condition of different Mach numbers while shock wave focusing.

  12. Optical Coupling Structures of Fiber-Optic Mach-Zehnder Interferometers Using CO2 Laser Irradiation

    Directory of Open Access Journals (Sweden)

    Chien-Hsing Chen

    2014-01-01

    Full Text Available The Mach-Zehnder interferometer (MZI can be used to test changes in the refractive index of sucrose solutions at different concentrations. However, the popularity of this measurement tool is limited by its substantial size and portability. Therefore, the MZI was integrated with a small fiber-optic waveguide component to develop an interferometer with fiber-optic characteristics, specifically a fiber-optic Mach-Zehnder interferometer (FO-MZI. Optical fiber must be processed to fabricate two optical coupling structures. The two optical coupling structures are a duplicate of the beam splitter, an optical component of the interferometer. Therefore, when the sensor length and the two optical coupling structures vary, the time or path for optical transmission in the sensor changes, thereby influencing the back-end interference signals. The researchers successfully developed an asymmetrical FO-MZI with sensing abilities. The spacing value between the troughs of the sensor length and interference signal exhibited an inverse relationship. In addition, image analysis was employed to examine the size-matching relationship between various sensor lengths and the coupling and decoupling structure. Furthermore, the spectral wavelength shift results measured using a refractive index sensor indicate that FO-MZIs with a sensor length of 38 mm exhibited excellent sensitivity, measuring 59.7 nm/RIU.

  13. Mach Cones and Hydrodynamic Flow Probing Big Bang Matter in the Laboratory

    CERN Document Server

    Betz, Barbara; Stöcker, Horst

    2007-01-01

    A critical discussion of the present signals for the phase transition to quark-gluon plasma (QGP) is given. Since hadronic rescattering models predict much larger flow than observed from 1 to 50 A GeV laboratory bombarding energies, this observation is interpreted as potential evidence for a first-order phase transition at high baryon density. A detailed discussion of the collective flow as a barometer for the equation of state (EoS) of hot dense matter at RHIC follows. Here, hadronic rescattering models can explain $ 2$ GeV/c. This is interpreted as an evidence for the production of superdense matter at RHIC. The connection of $v_2$ to jet suppression is examined. A study of Mach shocks generated by fast partonic jets propagating through the QGP is given. The main goal is to take into account different types of collective motion during the formation and evolution of this matter. A significant deformation of Mach shocks in central Au+Au collisions at RHIC and LHC energies as compared to the case of jet propag...

  14. The density variance - Mach number relation in isothermal and non-isothermal adiabatic turbulence

    CERN Document Server

    Nolan, Chris A; Sutherland, Ralph S

    2015-01-01

    The density variance - Mach number relation of the turbulent interstellar medium is relevant for theoretical models of the star formation rate, efficiency, and the initial mass function of stars. Here we use high-resolution hydrodynamical simulations with grid resolutions of up to 1024^3 cells to model compressible turbulence in a regime similar to the observed interstellar medium. We use Fyris Alpha, a shock-capturing code employing a high-order Godunov scheme to track large density variations induced by shocks. We investigate the robustness of the standard relation between the logarithmic density variance (sigma_s^2) and the sonic Mach number (M) of isothermal interstellar turbulence, in the non-isothermal regime. Specifically, we test ideal gases with diatomic molecular (gamma = 7/5) and monatomic (gamma = 5/3) adiabatic indices. A periodic cube of gas is stirred with purely solenoidal forcing at low wavenumbers, leading to a fully-developed turbulent medium. We find that as the gas heats in adiabatic comp...

  15. A NOVEL SLIGHTLY COMPRESSIBLE MODEL FOR LOW MACH NUMBER PERFECT GAS FLOW CALCULATION

    Institute of Scientific and Technical Information of China (English)

    邓小刚; 庄逢甘

    2002-01-01

    By analyzing the characteristics of low Mach number perfect gas flows, a novel Slightly Compressible Model (SCM) for low Mach number perfect gas flows is derived. In view of numerical calculations, this model is proved very efficient,for it is kept within the p-v frame but does not have to satisfy the time consuming divergence-free condition in order to get the incompressible Navier-Stokes equation solutions. Writing the equations in the form of conservation laws, we have derived the characteristic systems which are necessary for numerical calculations. A cellcentered finite-volume method with flux difference upwind-biased schemes is used for the equation solutions and a new Exact Newton Relaxation (ENR) implicit method is developed. Various computed results are presented to validate the present model.Laminar flow solutions over a circular cylinder with wake developing and vortex shedding are presented. Results for inviscid flow over a sphere are compared in excellent agreement with the exact analytic incompressible solution. Three-dimensional viscous flow solutions over sphere and prolate spheroid are also calculated and compared well with experiments and other incompressible solutions. Finally, good convergent performaces are shown for sphere viscous flows.

  16. Airfoil Aeroelastic Flutter Analysis Based on Modified Leishman-Beddoes Model at Low Mach Number

    Institute of Scientific and Technical Information of China (English)

    SHAO Song; ZHU Qinghua; ZHANG Chenglin; NI Xianping

    2011-01-01

    Based on modified Leishman-Beddoes(L-B)state space model at low Mach number(lower than 0.3),the airfoil aeroelastic system is presented in this paper.The main modifications for L-B model include a new dynamic stall criterion and revisions of normal force and pitching moment coefficient.The bifurcation diagrams,the limit cycle oscillation (LCO)phase plane plots and the time domain response figures are applied to investigating the stall flutter bifurcation behavior of airfoil aeroelastic systems with symmetry or asymmetry.It is shown that the symmetric periodical oscillation happens after subcritical bifurcation caused by dynamic stall,and the asymmetric periodical oscillation,which is caused by the interaction of dynamic stall and static divergence,only happens in the airfoil aeroelastic system with asymmetry.Validations of the modified L-B model and the airfoil aeroelastic system are presented with the experimental airload data of NACA0012 and OA207 and experimental stall flutter data of NACA0012 respectively.Results demonstrate that the airfoil aeroelastic system presented in this paper is effective and accurate,which can be applied to the investigation of airfoil stall flutter at low Mach number.

  17. The role of density-dependence regulation in the misleading effect of the Aznalcollar mining spill on the booted eagle fecundity.

    Science.gov (United States)

    Gil-Jiménez, Esperanza; Manzano, Javier; Casado, Eva; Ferrer, Miguel

    2017-04-01

    The aim of this study was to assess the exposure and potential effects of the toxic elements released by the Aznalcollar spillage on the fecundity of the booted eagle (Hieraetus pennatus) population of Doñana National Park. We measured As, Cd, Cu, Pb, Zn, Sb and Tl levels in the blood of 24 individuals after the accident and also used data of reproductive performance of the species from 1976 to 2000. While As, Sb and Tl were below their detection limits and only 3 samples were above detection limit for Cd (0.02-0.04μg/dl), mean levels of Cu, Zn and Pb (μg/dl) were found to be 38.736, 532.937 and 0.719, respectively, in fledglings; and 66.112, 652.571 and 1.825, respectively, in adults. These levels were higher in adults, but they did not differ significantly between age classes and were at safe levels. In addition, a positive relationship between relative fecundity and the combination of Cu, Zn and Pb was observed. Following the mining spill, the mean population fecundity was lower (0.536 fledglings per pair in the population) than before (1.093). However, the decrease in fecundity over time was also related to the increase of breeding pairs, suggesting a density-dependent regulation and nullifying the mining spillage effect. Thus, although raptors have proved to be highly valuable biomonitors of environmental pollution, we must be especially cautious and go beyond the apparent effects that sometimes we quickly believe to detect, leading us to reach mistaken conclusions that could affect our management plans. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Effects of the Mach number on the evolution of vortex-surface fields in compressible Taylor-Green flows

    Science.gov (United States)

    Peng, Naifu; Yang, Yue

    2016-11-01

    We investigate the evolution of vortex-surface fields (VSFs) in viscous compressible Taylor-Green flows. The VSF is applied to the direct numerical simulation of the Taylor-Green flows at a range of Mach numbers from Ma = 0 . 6 to Ma = 2 . 2 for characterizing the Mach-number effects on evolving vortical structures. We find that the dilatation and baroclinic force strongly influence the geometry of vortex surfaces and the energy dissipation rate in the transitional stage. The vortex tubes in compressible flows are less curved than those in incompressible flows, and the maximum dissipation rate occurs earlier in high-Mach-number flows perhaps owing to the conversion of kinetic energy into heat. Moreover, the relations between the evolutionary geometry of vortical structures and flow statistics are discussed. This work has been supported in part by the National Natural Science Foundation of China (Grant Nos. 11522215 and 11521091), and the Thousand Young Talents Program of China.

  19. Generation and Evolution of High-Mach-Number Laser-Driven Magnetized Collisionless Shocks in the Laboratory

    Science.gov (United States)

    Schaeffer, D. B.; Fox, W.; Haberberger, D.; Fiksel, G.; Bhattacharjee, A.; Barnak, D. H.; Hu, S. X.; Germaschewski, K.

    2017-07-01

    We present the first laboratory generation of high-Mach-number magnetized collisionless shocks created through the interaction of an expanding laser-driven plasma with a magnetized ambient plasma. Time-resolved, two-dimensional imaging of plasma density and magnetic fields shows the formation and evolution of a supercritical shock propagating at magnetosonic Mach number Mms≈12 . Particle-in-cell simulations constrained by experimental data further detail the shock formation and separate dynamics of the multi-ion-species ambient plasma. The results show that the shocks form on time scales as fast as one gyroperiod, aided by the efficient coupling of energy, and the generation of a magnetic barrier between the piston and ambient ions. The development of this experimental platform complements present remote sensing and spacecraft observations, and opens the way for controlled laboratory investigations of high-Mach number collisionless shocks, including the mechanisms and efficiency of particle acceleration.

  20. 基于HiveBoard的嵌入式系统1卡启动的研究与实现%Research and Implementation of System Booting with a Single SD-Card Based on the HiveBoard

    Institute of Scientific and Technical Information of China (English)

    陆清茹; 史先强; 辛海燕

    2014-01-01

    HiveBoard is a single board computer designed by the researchers of the Southeast University. It’s based on the domestic SOC which is called SEP6200. It implements the whole system booting using a single SD card. In this paper,the author introduces the basic configuration of the HiveBoard. Then,the paper analyzes the data storage structure of SD card and the knowledge of the FAT16 file system. Finally, the author expounds that how to integratethe U-Boot,the Linux kernel image and the file-system in the single SD card and the whole process how the HiveBoard is booted by this SD card.%HiveBoard是东南大学研究人员设计的一款基于国产微处理器的信用卡大小的单板计算机,它实现了使用一张SD卡一次实现嵌入式系统的完整启动。首先介绍了HiveBoard基本配置,分析了典型嵌入式系统的启动方式以及SD卡数据存储与FAT16文件系统相关知识,重点阐述了设计者巧妙地将嵌入式系统所必须的U-Boot、Linux内核和文件系统集成在一张SD卡中并实现完整系统启动的原理和方法,并呈现了整个启动流程。

  1. Transition boundary between regular and Mach reflections for a moving shock interacting with a wedge in inviscid and polytropic air

    Science.gov (United States)

    Hryniewicki, M. K.; Gottlieb, J. J.; Groth, C. P. T.

    2017-07-01

    The transition boundary separating the region of regular reflection from the regions of single-, transitional-, and double-Mach reflections for a planar shock wave moving in air and interacting with an inclined wedge in a shock tube is studied by both analytical methods and computational-fluid-dynamic simulations. The analytical solution for regular reflection and the corresponding solutions from the extreme-angle (detachment), sonic, and mechanical-equilibrium transition criteria by von Neumann (Oblique reflection of shocks, Explosive Research Report No. 12, Navy Department, Bureau of Ordnance, U.S. Dept. Comm. Tech. Serv. No. PB37079 (1943). Also, John von Neumann, Collected Works, Pergamon Press 6, 238-299, 1963) are first revisited and revised. The boundary between regular and Mach reflection is then determined numerically using an advanced computational-fluid-dynamics algorithm to solve Euler's inviscid equations for unsteady motion in two spatial dimensions. This numerical transition boundary is determined by post-processing many closely stationed flow-field simulations, to determine the transition point when the Mach stem of the Mach-reflection pattern just disappears and this pattern then transcends into that of regular reflection. The new numerical transition boundary is shown to agree well with von Neumann's closely spaced sonic and extreme-angle boundaries for weak incident shock Mach numbers from 1.0 to 1.6, but this new boundary trends upward and above von Neumann's sonic and extreme-angle boundaries by a couple of degrees at larger shock Mach numbers from 1.6 to 4.0. Furthermore, the new numerically determined transition boundary is shown to agree well with very few available experimental data obtained from previous experiments designed to reflect two symmetrical moving oblique shock waves along a plane without a shear or boundary layer.

  2. Transition boundary between regular and Mach reflections for a moving shock interacting with a wedge in inviscid and polytropic air

    Science.gov (United States)

    Hryniewicki, M. K.; Gottlieb, J. J.; Groth, C. P. T.

    2016-12-01

    The transition boundary separating the region of regular reflection from the regions of single-, transitional-, and double-Mach reflections for a planar shock wave moving in air and interacting with an inclined wedge in a shock tube is studied by both analytical methods and computational-fluid-dynamic simulations. The analytical solution for regular reflection and the corresponding solutions from the extreme-angle (detachment), sonic, and mechanical-equilibrium transition criteria by von Neumann (Oblique reflection of shocks, Explosive Research Report No. 12, Navy Department, Bureau of Ordnance, U.S. Dept. Comm. Tech. Serv. No. PB37079 (1943). Also, John von Neumann, Collected Works, Pergamon Press 6, 238-299, 1963) are first revisited and revised. The boundary between regular and Mach reflection is then determined numerically using an advanced computational-fluid-dynamics algorithm to solve Euler's inviscid equations for unsteady motion in two spatial dimensions. This numerical transition boundary is determined by post-processing many closely stationed flow-field simulations, to determine the transition point when the Mach stem of the Mach-reflection pattern just disappears and this pattern then transcends into that of regular reflection. The new numerical transition boundary is shown to agree well with von Neumann's closely spaced sonic and extreme-angle boundaries for weak incident shock Mach numbers from 1.0 to 1.6, but this new boundary trends upward and above von Neumann's sonic and extreme-angle boundaries by a couple of degrees at larger shock Mach numbers from 1.6 to 4.0. Furthermore, the new numerically determined transition boundary is shown to agree well with very few available experimental data obtained from previous experiments designed to reflect two symmetrical moving oblique shock waves along a plane without a shear or boundary layer.

  3. Analysis of gas turbine engines using water and oxygen injection to achieve high Mach numbers and high thrust

    Science.gov (United States)

    Henneberry, Hugh M.; Snyder, Christopher A.

    1993-01-01

    An analysis of gas turbine engines using water and oxygen injection to enhance performance by increasing Mach number capability and by increasing thrust is described. The liquids are injected, either separately or together, into the subsonic diffuser ahead of the engine compressor. A turbojet engine and a mixed-flow turbofan engine (MFTF) are examined, and in pursuit of maximum thrust, both engines are fitted with afterburners. The results indicate that water injection alone can extend the performance envelope of both engine types by one and one-half Mach numbers at which point water-air ratios reach 17 or 18 percent and liquid specific impulse is reduced to some 390 to 470 seconds, a level about equal to the impulse of a high energy rocket engine. The envelope can be further extended, but only with increasing sacrifices in liquid specific impulse. Oxygen-airflow ratios as high as 15 percent were investigated for increasing thrust. Using 15 percent oxygen in combination with water injection at high supersonic Mach numbers resulted in thrust augmentation as high as 76 percent without any significant decrease in liquid specific impulse. The stoichiometric afterburner exit temperature increased with increasing oxygen flow, reaching 4822 deg R in the turbojet engine at a Mach number of 3.5. At the transonic Mach number of 0.95 where no water injection is needed, an oxygen-air ratio of 15 percent increased thrust by some 55 percent in both engines, along with a decrease in liquid specific impulse of 62 percent. Afterburner temperature was approximately 4700 deg R at this high thrust condition. Water and/or oxygen injection are simple and straightforward strategies to improve engine performance and they will add little to engine weight. However, if large Mach number and thrust increases are required, liquid flows become significant, so that operation at these conditions will necessarily be of short duration.

  4. Effect of Pressure Gradients on the Initiation of PBX-9502 via Irregular (Mach) Reflection of Low Pressure Curved Shock Waves

    Energy Technology Data Exchange (ETDEWEB)

    Hull, Lawrence Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Miller, Phillip Isaac [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moro, Erik Allan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-28

    In the instance of multiple fragment impact on cased explosive, isolated curved shocks are generated in the explosive. These curved shocks propagate and may interact and form irregular or Mach reflections along the interaction loci, thereby producing a single shock that may be sufficient to initiate PBX-9501. However, the incident shocks are divergent and their intensity generally decreases as they expand, and the regions behind the Mach stem interaction loci are generally unsupported and allow release waves to rapidly affect the flow. The effects of release waves and divergent shocks may be considered theoretically through a “Shock Change Equation”.

  5. Investigation on characteristics of self-organization in Mach-Zehnder erbium-doped fiber laser cavity

    Institute of Scientific and Technical Information of China (English)

    Fengnian Liu; Bo Liu; Bangcai Huang; Guiyun Kai; Shuzhong Yuan; Xiaoyi Dong

    2008-01-01

    The characteristics of coherent coupling in Mach-Zehnder erbium-doped fiber laser cavity are experimentally studied.By virtue of a seemly controlling of length difference between two interferometric arms,the obtained comb-like spectrum of interferometer resonator with a period of 0.06 nm commendably agrees with the theory of self-organization coherence The coherent output exits from the output mirror of a fiber Bragg grating with 4.5% reflectivity.A high coherent combining efficiency of 94% is obtained.Investigation on characteristics of the leak power opens out self-organization mechanism in Mach-Zehnder composite cavity.

  6. 基于WinPE启动的U盘量产技术研究与实现%Research and implementation of mass production technology of U-Disk boot on WinPE

    Institute of Scientific and Technical Information of China (English)

    顾超捷; 周玉洁

    2011-01-01

    针对传统的以软盘和光盘的方式来恢复操作系统过于繁复,并且在一些追求轻薄的笔记本上已经不再配备软驱和光驱,U盘以它的轻便和容量大,脱颖而出,故而制作以U盘启动操作系统是大势所趋.创新点在于通过对WindowXp平台下的文件系统FAT16,FAT32,根目录表项以及MBR,DBR的深入研究,设计嵌入式软件方便快捷地实现具有WinPE操作系统的U盘启动功能的量产,并且考虑到不同品牌计算机的兼容性,提供用户USB-CD和USB-ZIP两种启动模式.实验结果表明,本方法最大限度地方便了用户对启动功能和u盘本身的使用.%Aiming at that it is excessively complicated to restore the operating system by traditional floppy disks and CD-ROM, U-Disk stands out by right of its lightweight and large capacity and therefore it is general trend to start the operating system by U disk. As an innovation of the this paper, through the depth research of file system FAT16 , FAT32,the root directory table enty, as well as MBR,DBR on the WindowXP platform, designing embedded software is fully used easily and quickly to achieve mass production of boot U disk with WinPE OS booting to recover breakdown system, which provide two kinds of boot mode of USB-CD and USB-ZIP, taking into account the compatibility of different brands of computer. The experimental results show that this method maxinuzes convenient for user to use boot function and storage capacity of U disk.

  7. Main: Sequences [KOME

    Lifescience Database Archive (English)

    Full Text Available Sequences Nucleotide Sequence Nucleotide sequence of full length cDNA (trimmed sequence) kome_ine_full_seq...uence_db.fasta.zip kome_ine_full_sequence_db.zip kome_ine_full_sequence_db ...

  8. 60dB high-extinction auto-configured Mach--Zehnder interferometer

    CERN Document Server

    Wilkes, Callum M; Wang, Jianwei; Santagati, Raffaele; Paesani, Stefano; Zhou, Xiaoqi; Miller, David A B; Marshall, Graham D; Thompson, Mark G; O'Brien, Jeremy L

    2016-01-01

    Imperfections in integrated photonics manufacturing have a detrimental effect on the maximal achievable visibility in interferometric architectures. These limits have profound implications for further photonics technological developments and in particular for quantum photonics technologies. Active optimisation approaches, together with reconfigurable photonics, have been proposed as a solution to overcome this. In this paper, we demonstrate an ultra-high (>60 dB) extinction ratio in a silicon photonic device consisting of cascaded Mach-Zehnder interferometers, in which additional interferometers function as variable beamsplitters. The imperfections of fabricated beamsplitters are compensated using an automated progressive optimization algorithm with no requirement for pre-calibration. This work shows the possibility of integrating and accurately controlling linear-optical components for large-scale quantum information processing and other applications.

  9. A Thermally Annealed Mach-Zehnder Interferometer for High Temperature Measurement

    Directory of Open Access Journals (Sweden)

    Zhongyao Feng

    2014-08-01

    Full Text Available An in-fiber Mach-Zehnder interferometer (MZI for high temperature measurement is proposed and experimentally demonstrated. The device is constructed of a piece of thin-core fiber (TCF sandwiched between two short sections of multimode fiber (MMF, i.e., a MMF-TCF-MMF structure. A well-defined interference spectrum is obtained owing to the core-mismatch, and the interference dips are sensitive to the ambient temperature. The experimental results show that the proposed interferometer is capable of high temperature measurement up to 875 °C with a sensitivity of 92 pm/°C over repeated measurements. The explored wavelength drop point may limit the measurement range, which can be improved by repeated thermal annealing.

  10. Tests of Full-Scale Helicopter Rotors at High Advancing Tip Mach Numbers and Advance Ratios

    Science.gov (United States)

    Biggers, James C.; McCloud, John L., III; Stroub, Robert H.

    2015-01-01

    As a continuation of the studies of reference 1, three full-scale helicopter rotors have been tested in the Ames Research Center 40- by SO-foot wind tunnel. All three of them were two-bladed, teetering rotors. One of the rotors incorporated the NACA 0012 airfoil section over the entire length of the blade. This rotor was tested at advance ratios up to 1.05. Both of the other rotors were tapered in thickness and incorporated leading-edge camber over the outer 20 percent of the blade radius. The larger of these rotors was tested at advancing tip Mach numbers up to 1.02. Data were obtained for a wide range of lift and propulsive force, and are presented without discussion.

  11. Manipulation of quantum states in a memory cell: controllable Mach-Zehnder interferometer

    Science.gov (United States)

    Losev, A. S.; Golubeva, T. Yu; Golubev, Yu M.

    2017-05-01

    In this article, we consider the possibility of manipulation of quantum signals, ensured by the use of the tripod-type atomic memory cell. We show that depending on a configuration of driving fields at the writing and reading, such a cell allows the signal to both be stored and transformed. It is possible to provide the operation of the memory cell in a Mach-Zehnder interferometer mode passing two successive pulses at the input. We proposed a procedure of partial signal readout that provides entanglement between the retrieved light and the atomic ensemble. Thus, we have shown that a tripod atomic cell is a promising candidate to implement quantum logical operations, including two-qubit ones, which can be performed on the basis of only one cell.

  12. Interactive tutorial to improve student understanding of single photon experiments involving a Mach-Zehnder interferometer

    Science.gov (United States)

    Marshman, Emily; Singh, Chandralekha

    2016-03-01

    We have developed and evaluated a quantum interactive learning tutorial (QuILT) on a Mach-Zehnder interferometer with single photons to expose upper-level students in quantum mechanics courses to contemporary quantum optics applications. The QuILT strives to help students develop the ability to apply fundamental quantum principles to physical situations in quantum optics and explore the differences between classical and quantum ideas. The QuILT adapts visualization tools to help students build physical intuition about counter-intuitive quantum optics phenomena with single photons including a quantum eraser setup and focuses on helping them integrate qualitative and quantitative understanding. We discuss findings from in-class evaluations.

  13. Temperature characterization of integrated optical all-polymer Mach-Zehnder interferometers

    Science.gov (United States)

    Xiao, Yanfen; Hofmann, Meike; Wang, Ziyu; Langenecker, Alexa; Shermann, Stanislav; Gleissner, Uwe; Zappe, Hans

    2016-04-01

    Two new design concepts for all-polymer-based integrated optical Mach-Zehnder interferometers in foil as chemical or bio-chemical sensors are presented. Fabricated with hot-embossing and printing techniques, these all polymer optical components are designed for low-cost fabrication and yield highly sensitive response to external refractive index changes. Compared to traditional semiconductor based systems, these polymer sensors do not need the interaction window and do not require a cleanroom for fabrication. The optical response of the asymmetric interferometers to temperature variations is determined theoretically and compared for two designs. Using the designed asymmetric interferometer, a chemical micro-fluidic test system with temperature controller experimentally demonstrates the sensors' temperature characteristics.

  14. High-speed carrier-depletion silicon Mach-Zehnder optical modulators with lateral PN junctions

    Directory of Open Access Journals (Sweden)

    Graham Trevor Reed

    2014-12-01

    Full Text Available This paper presents new experimental data from a lateral PN junction silicon Mach-Zehnder optical modulator. Efficiencies in the 1.4V.cm to 1.9V.cm range are demonstrated for drive voltages between 0V and 6V. High speed operation up to 52Gbit/s is also presented. The performance of the device which has its PN junction positioned in the centre of the waveguide is then compared to previously reported data from a lateral PN junction device with the junction self-aligned to the edge of the waveguide rib. An improvement in modulation efficiency is demonstrated when the junction is positioned in the centre of the waveguide. Finally we propose schemes for achieving high modulation efficiency whilst retaining self-aligned formation of the PN junction.

  15. Simulation of acousto-optical interaction in a Mach-Zehnder interferometer

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard; Sigmund, Ole; Jensen, Jakob Søndergaard

    ]. In [3] it is explained how a SAW can be employed to modulate the output light of a GaAs Mach-Zehnder interferometer (MZI) and experimental results with a relative modulation depth of 40 % are presented. To modulate the light using a MZI a SAW is transmitted perpendicularly to the two waveguide arms...... in waveguide structures is to let the light interact with surface acoustic waves (SAW) [1]. SAWs are elastic waves that propagate along a material surface, they consist of a longitudinal and a shear component and they have most of their energy density concentrated within one wavelength of the surface [2...... and the elastic stress field from the SAW results in a periodic change of the refractive index and therefore a periodical phase change in the waveguide arms. At a wave crest the refractive index will increase and at a trough it will decrease. Thus, if the distance between the arms is chosen as an unequal multiple...

  16. Calibration of the 7—Equation Transition Model for High Reynolds Flows at Low Mach

    Science.gov (United States)

    Colonia, S.; Leble, V.; Steijl, R.; Barakos, G.

    2016-09-01

    The numerical simulation of flows over large-scale wind turbine blades without considering the transition from laminar to fully turbulent flow may result in incorrect estimates of the blade loads and performance. Thanks to its relative simplicity and promising results, the Local-Correlation based Transition Modelling concept represents a valid way to include transitional effects into practical CFD simulations. However, the model involves coefficients that need tuning. In this paper, the γ—equation transition model is assessed and calibrated, for a wide range of Reynolds numbers at low Mach, as needed for wind turbine applications. An aerofoil is used to evaluate the original model and calibrate it; while a large scale wind turbine blade is employed to show that the calibrated model can lead to reliable solutions for complex three-dimensional flows. The calibrated model shows promising results for both two-dimensional and three-dimensional flows, even if cross-flow instabilities are neglected.

  17. Mach's Principle and Model for a Broken Symmetric Theory of Gravity

    CERN Document Server

    Bisabr, Y

    2003-01-01

    We investigate spontaneous symmetry breaking in a conformally invariant gravitational model. In particular, we use a conformally invariant scalar tensor theory as the vacuum sector of a gravitational model to examine the idea that gravitational coupling may be the result of a spontanous symmetry breaking. In this model matter is taken to be coupled with a metric which is different but conformally related to the metric appearing explicitly in the vacuum sector. We show that after the spontanous symmetry breaking the resulting theory is consistent with Mach's principle in the sense that inertial masses of particles have variable configurations in a cosmological context. Moreover, our analysis allows to construct a mechanism in which the resulting large vacuum energy density relaxes during evolution of the universe.

  18. Hypersonic characteristics of an advanced aerospace plane at Mach 20.3

    Science.gov (United States)

    Mccandless, R. S.

    1985-01-01

    Wind-tunnel studies have been performed in the Langley Hypersonic Helium Tunnel Facility to obtain static longitudinal and lateral-directional aerodynamic characteristics of an advanced aerospace plane concept. The nominal test conditions are a Mach number of 20.3 and a Reynolds number of 6.8 x 10 to the 6th power per foot at angles of attack from 0 to 25 deg and angles of sideslip of -3 and 0 deg. Stability and control characteristics are obtained for several deflections of the elevators, elevons, and rudder. In addition, a modified canopy is examined. The results indicate that this vehicle is longitudinally stable at angles of attack near the maximum lift-drag ratio. Also, the vehicle is shown to be directionally unstable with positive dihedral effect.

  19. Photonic crystal fiber in-line Mach-Zehnder interferometer for explosive detection.

    Science.gov (United States)

    Tao, Chuanyi; Wei, Heming; Feng, Wenlin

    2016-02-08

    We report a photonic crystal fiber (PCF) in-line Mach-Zehnder interferometer used as a gas sensor device which exhibits high sensitivity to the explosive trinitrotoluene (TNT). The interferometric sensor head is formed by embedding a segment of large-mode-area/grapefruit PCF between standard single-mode fibers via butt coupling, which produces two small air gaps in between terminated fiber ends with ceramic ferrule connectors as coupling regions, which also serve as inlet/outlet for the gas. The spectral response of the interferometer is investigated in terms of its wavelength spectrum. The selectivity to TNT vapor is achieved by immobilizing a molecular recognition ployallylamine layer on the inner surface of the holey region of the PCF. The TNT-induced variations of the interference fringes are measured and the sensing capability of the proposed sensor is demonstrated experimentally.

  20. Mach-Zehnder interferometric photonic crystal fiber for low acoustic frequency detections

    Energy Technology Data Exchange (ETDEWEB)

    Pawar, Dnyandeo; Rao, Ch. N.; Kale, S. N., E-mail: sangeetakale2004@gmail.com [Department of Applied Physics, Defence Institute of Advanced Technology (DU), Girinagar, Pune 411 025, Maharashtra (India); Choubey, Ravi Kant [Department of Applied Physics, Amity Institute of Applied Sciences, Amity University, Noida 201 313 (India)

    2016-01-25

    Low frequency under-water acoustic signal detections are challenging, especially for marine applications. A Mach-Zehnder interferometric hydrophone is demonstrated using polarization-maintaining photonic-crystal-fiber (PM-PCF), spliced between two single-mode-fibers, operated at 1550 nm source. These data are compared with standard hydrophone, single-mode and multimode fiber. The PM-PCF sensor shows the highest response with a power shift (2.32 dBm) and a wavelength shift (392.8 pm) at 200 Hz. High birefringence values and the effect of the imparted acoustic pressure on this fiber, introducing the difference between the fast and slow axis changes, owing to the phase change in the propagation waves, demonstrate the strain-optic properties of the sensor.

  1. On the proper Mach number and ratio of specific heats for modeling the Venus bow shock

    Science.gov (United States)

    Tatrallyay, M.; Russell, C. T.; Luhmann, J. G.; Barnes, A.; Mihalov, J. D.

    1984-01-01

    Observational data from the Pioneer Venus Orbiter are used to investigate the physical characteristics of the Venus bow shock, and to explore some general issues in the numerical simulation of collisionless shocks. It is found that since equations from gas-dynamic (GD) models of the Venus shock cannot in general replace MHD equations, it is not immediately obvious what the optimum way is to describe the desired MHD situation with a GD code. Test case analysis shows that for quasi-perpendicular shocks it is safest to use the magnetospheric Mach number as an input to the GD code. It is also shown that when comparing GD predicted temperatures with MHD predicted temperatures total energy should be compared since the magnetic energy density provides a significant fraction of the internal energy of the MHD fluid for typical solar wind parameters. Some conclusions are also offered on the properties of the terrestrial shock.

  2. Interactive tutorial to improve student understanding of single photon experiments involving a Mach-Zehnder Interferometer

    CERN Document Server

    Marshman, Emily

    2016-01-01

    We have developed and evaluated a Quantum Interactive Learning Tutorial (QuILT) on a Mach-Zehnder Interferometer with single photons to expose upper-level students in quantum mechanics courses to contemporary quantum optics applications. The QuILT strives to help students develop the ability to apply fundamental quantum principles to physical situations in quantum optics and explore the differences between classical and quantum ideas. The QuILT adapts visualization tools to help students build physical intuition about counter-intuitive quantum optics phenomena with single photons including a quantum eraser setup and focuses on helping them integrate qualitative and quantitative understanding. We discuss findings from in-class evaluations.

  3. Relativistic Electron Shock Drift Acceleration in Low Mach Number Galaxy Cluster Shocks

    CERN Document Server

    Matsukiyo, Shuichi; Yamazaki, Ryo; Umeda, Takayuki

    2011-01-01

    An extreme case of electron shock drift acceleration in low Mach number collisionless shocks is investigated as a plausible mechanism of initial acceleration of relativistic electrons in large-scale shocks in galaxy clusters where upstream plasma temperature is of the order of 10 keV and a degree of magnetization is not too small. One-dimensional electromagnetic full particle simulations reveal that, even though a shock is rather moderate, a part of thermal incoming electrons are accelerated and reflected through relativistic shock drift acceleration and form a local nonthermal population just upstream of the shock. The accelerated electrons can self-generate local coherent waves and further be back-scattered toward the shock by those waves. This may be a scenario for the first stage of the electron shock acceleration occurring at the large-scale shocks in galaxy clusters such as CIZA J2242.8+5301 which has well defined radio relics.

  4. Terahertz Detection Based on Spectral-Domain Interferometry Using Mach-Zehnder Interferometer

    Science.gov (United States)

    Ibrahim, Akram; Sharma, Gargi; Singh, Kanwarpal; Ozaki, Tsuneyuki

    2016-09-01

    We demonstrate the use of a Mach-Zehnder interferometer (MZI) to improve the performance of terahertz electric field measurements based on spectral-domain interferometry. The interferometer is introduced into the probe beam line to improve the temporal overlap between the two probe pulses. The probe pulse in the sample arm of the interferometer passes through the detection crystal and overlaps with the terahertz pulse, while the probe pulse in the reference arm does not. We measure the phase change between spectral components of these two pulses using spectral-domain interferometry. Using this new technique, we enable an unlimited temporal scanning window without the loss in the signal-to-noise ratio, thus overcoming the major limitation of conventional spectral-domain interferometry techniques for terahertz electric field detection.

  5. Effects of wind-tunnel noise on swept-cylinder transition at Mach 3.5

    Science.gov (United States)

    Creel, T. R., Jr.; Beckwith, I. E.; Chen, F.-J.

    1986-01-01

    Transition data are reported for circular cylinders at swept angles of 45 and 60 degrees in the Mach 3.5 pilot-low-disturbance tunnel where free-stream noise levels are varied from approximately .05-0.5 percent in terms of the rms fluctuating pressure normalized by the mean static pressure. Results indicate that end plate or boundary layer trip disturbances at the upstream end of the cylinders cause turbulent flow along the entire test Reynolds number range of 10-170 thousand per inch. With all end plate and trip disturbances removed, transition at the attachment lines occurred at free-stream Reynolds numbers based on diameters of about 70-80 thousand, independent of stream noise levels. The installation of small trips on the attachement lines caused transition at lower Reynolds numbers, depending on both the roughness height and the wind tunnel noise level.

  6. Comparison of hot-wire measurement techniques in a Mach 3 pilot quiet tunnel

    Science.gov (United States)

    Chen, F.-J.; Beckwith, I. E.

    1985-01-01

    Disturbance measurements were made in the free stream of a small Mach 3 quiet tunnel using constant-current and constant-temperature anemometers (CCA and CTA). Data from the two types of instruments are compared in terms of frequency response and normalized rms levels of mass flow fluctuations. The mode-diagram analysis of the CCA data produces reliable results because the frequency response is consistent for a wide range of overheat ratios. However, the mode-diagram results for the CTA data cannot be used due to the rapidly decreasing frequency response with decreasing overheat ratio. Only the mass flow fluctuations at high overheat ratio can be obtained with the CTA system, and they can be as much as 50 percent higher than those from the CCA system. Possible reasons for these measurement differences between the two systems are considered.

  7. Low-Mach-number turbulence in interstellar gas revealed by radio polarization gradients

    CERN Document Server

    Gaensler, Bryan M; Burkhart, Blakesley; Newton-McGee, Katherine J; Ekers, Ronald D; Lazarian, Alex; McClure-Griffiths, Naomi M; Robishaw, Timothy; Dickey, John M; Green, Anne J; 10.1038/nature10446

    2011-01-01

    The interstellar medium of the Milky Way is multi-phase, magnetized and turbulent. Turbulence in the interstellar medium produces a global cascade of random gas motions, spanning scales ranging from 100 parsecs to 1000 kilometres. Fundamental parameters of interstellar turbulence such as the sonic Mach number (the speed of sound) have been difficult to determine because observations have lacked the sensitivity and resolution to directly image the small-scale structure associated with turbulent motion. Observations of linear polarization and Faraday rotation in radio emission from the Milky Way have identified unusual polarized structures that often have no counterparts in the total radiation intensity or at other wavelengths, and whose physical significance has been unclear. Here we report that the gradient of the Stokes vector (Q,U), where Q and U are parameters describing the polarization state of radiation, provides an image of magnetized turbulence in diffuse ionized gas, manifested as a complex filamenta...

  8. LDA measurements in a Mach 2 flow over a rearward facing step with staged transverse injection

    Science.gov (United States)

    Wang, J.-A.; Dancey, C. L.

    1992-01-01

    Measurements of the mean velocity field and selected turbulence statistics have been obtained via 2D LDA in a Mach 2 flow over a rearward facing step with downstream transverse injection. Axial mean velocity profiles, profiles of the axial and normal RMS levels, and the correlation coefficient between the axial and normal fluctuating components are presented for locations upstream of the step. These data, through comparison with other reported measurements in zero pressure gradient compressible boundary layers indicate that the boundary layers upstream of the step are consistent with 'quasi-equilibrium' turbulent boundary layers with the adiabatic wall boundary condition. Mean velocity field measurements on the symmetry plane of the tunnel are compared to laser induced iodine fluorescence measurements reported in the literature and obtained in the same facility. This comparison demonstrates the quality of the present LDA data set and shows that particle lag is not significant in the LDA measurements despite the complex nature of the downstream flow.

  9. SIERRA Low Mach Module: Fuego User Manual Version 4.44

    Energy Technology Data Exchange (ETDEWEB)

    Sierra Thermal/Fluid Team

    2017-04-01

    The SIERRA Low Mach Module: Fuego along with the SIERRA Participating Media Radiation Module: Syrinx, henceforth referred to as Fuego and Syrinx, respectively, are the key elements of the ASCI fire environment simulation project. The fire environment simulation project is directed at characterizing both open large-scale pool fires and building enclosure fires. Fuego represents the turbulent, buoyantly-driven incompressible flow, heat transfer, mass transfer, combustion, soot, and absorption coefficient model portion of the simulation software. Syrinx represents the participating-media thermal radiation mechanics. This project is an integral part of the SIERRA multi-mechanics software development project. Fuego depends heavily upon the core architecture developments provided by SIERRA for massively parallel computing, solution adaptivity, and mechanics coupling on unstructured grids.

  10. The effect of conical flowfields on the performance of waveriders at Mach 6

    Institute of Scientific and Technical Information of China (English)

    CUI Kai; YANG GuoWei

    2007-01-01

    The performance of 23 kinds of waveriders, derived from different conical flowfields, is analyzed by the numerical computation under the conditions of fight speed of Mach 6, attack angle of 0° and flight altitude of 30 km. These results indicate that the performance is influenced by the shapes and the width to height ratios (W/H ) of generating cones. The geometrical parameter and the lift coefficient are proportional to W/H, while the drag coefficient and the lift to drag ratio (L/D ) have extreme values. Considering the base drag and the computation errors, the waverider with the highest L/D is cut from the elliptical cone's flowfield (W/H = 1.5-1.618), and the configuration with the lowest drag can also be obtained at W/H = 1:1.5. Accordingly, good suggestions are proposed for practical design based on these computational results.

  11. Mach-Zehnder interferometric photonic crystal fiber for low acoustic frequency detections

    Science.gov (United States)

    Pawar, Dnyandeo; Rao, Ch. N.; Choubey, Ravi Kant; Kale, S. N.

    2016-01-01

    Low frequency under-water acoustic signal detections are challenging, especially for marine applications. A Mach-Zehnder interferometric hydrophone is demonstrated using polarization-maintaining photonic-crystal-fiber (PM-PCF), spliced between two single-mode-fibers, operated at 1550 nm source. These data are compared with standard hydrophone, single-mode and multimode fiber. The PM-PCF sensor shows the highest response with a power shift (2.32 dBm) and a wavelength shift (392.8 pm) at 200 Hz. High birefringence values and the effect of the imparted acoustic pressure on this fiber, introducing the difference between the fast and slow axis changes, owing to the phase change in the propagation waves, demonstrate the strain-optic properties of the sensor.

  12. Convective heat transport in stratified atmospheres at low and high Mach number

    CERN Document Server

    Anders, Evan H

    2016-01-01

    Convection in astrophysical systems is stratified and often occurs at high Rayleigh number (Ra) and low Mach number (Ma). Here we study stratified convection in the context of plane-parallel, polytropically stratified atmospheres. We hold the density stratification ($n_{\\rho}$) and Prandtl number (Pr) constant while varying Ma and Ra to determine the behavior of the Nusselt number (Nu), which quantifies the efficiency of convective heat transport. As Ra increases and $\\text{Ma} \\rightarrow 1$, a scaling of Nu $\\propto$ Ra$^{0.45}$ is observed. As Ra increases to a regime where Ma $\\geq 1$, this scaling gives way to a weaker Nu $\\propto$ Ra$^{0.19}$. In the regime of Ma $\\ll 1$, a consistent Nu $\\propto$ Ra$^{0.31}$ is retrieved, reminiscent of the Nu $\\propto$ Ra$^{2/7}$ seen in Rayleigh-B\\'{e}nard convection.

  13. Phase noise due to vibrations in Mach-Zehnder atom interferometers

    CERN Document Server

    Miffre, A; Büchner, M; Trénec, G; Vigué, J

    2006-01-01

    Atom interferometers are very sensitive to accelerations and rotations. This property, which has some very interesting applications, induces a deleterious phase noise due to the seismic noise of the laboratory and this phase noise is sufficiently large to reduce the fringe visibility in many experiments. We develop a model calculation of this phase noise in the case of Mach-Zehnder atom interferometers and we apply this model to our thermal lithium interferometer. We are able to explain the observed phase noise which has been detected through the rapid dependence of the fringe visibility with the diffraction order. We think that the dynamical model developed in the present paper should be very useful to reduce the vibration induced phase noise in atom interferometers, making many new experiments feasible.

  14. Pass-through Mach-Zehnder topologies for macroscopic quantum measurements

    CERN Document Server

    Khalili, F Ya

    2011-01-01

    Several relatively small-scale experimental setups aimed on prototyping of future laser gravitational-wave detectors and testing of new methods of quantum measurements with macroscopic mechanical objects, are under development now. In these devices, not devoted directly to the gravitational-wave detection, Mach-Zehnder interferometer with pass-through Fabry-Perot cavities in the arms can be used instead of the standard Michelson/Fabry-Perot one. The advantage of this topology is that it does not contain high-reflectivity end mirrors with multilayer coatings, which Brownian noise could constitute the major part of the noise budget of the Michelson/Fabry-Perot interferometers. We consider here two variants of this topology: the "ordinary" position meter scheme, and a new variant of the quantum speed meter.

  15. Effect of leading edge sweep on shock-shock interference at Mach 8

    Science.gov (United States)

    Glass, Christopher E.; Wieting, Allan R.; Holden, Michael S.

    1989-01-01

    These Mach 8 experimental results are applicable to the details of a shock-shock interference that may occur on an engine inlet of a hypersonic vehicle from a swept forebody shock interacting with a swept cowl leading edge bow shock or from a swept splitter plate shock interacting with a swept fuel injection strut bow shock. Peak surface pressure and heat transfer rate on the cylinder were about 10 and 30 times the undisturbed flow stagnation point value, respectively, for the 0 deg sweep test. A comparison of the 15 deg and 30 deg swept results with the 0 deg swept results shows that peak pressure was reduced about 13 percent and 44 percent, respectively, and peak heat transfer rate was reduced about 7 percent and 27 percent, respectively.

  16. On the Relevance of Low-Mach-Number Asymptotics in Thermodynamics of Heterogeneous, Immiscible Mixtures

    Science.gov (United States)

    Varsakelis, Christos; Papalexandris, Miltiadis V.

    2017-01-01

    A conundrum in non-equilibrium thermodynamics of heterogeneous mixtures with microstructure concerns the selection of thermodynamic currents and forces in the entropy production rate from the multitude of available options. The objective of this article is to demonstrate that the low-Mach-number approximation can narrow down this ambiguity. More specifically, by postulating that the post-constitutive equations are well behaved with respect to this perturbation analysis we assert that thermal non-equilibrium should be chosen as an independent force even if this requires the explicit manipulation of the entropy inequality. According to our analysis, alternative choices result in post-constitutive equations; the incompressible limit of which gives rise to questionable predictions.

  17. Optical waveguide biosensor based on cascaded Mach-Zehnder interferometer and ring resonator with Vernier effect

    Science.gov (United States)

    Jiang, Xianxin; Tang, Longhua; Song, Jinyan; Li, Mingyu; He, Jian-Jun

    2014-03-01

    Optical waveguide biosensors based on silicon-on-insulator (SOI) have been extensively investigated owing to its various advantages and many potential applications. In this article, we demonstrate a novel highly sensitive biosensor based on cascaded Mach-Zehnder interferometer (MZI) and ring resonator with the Vernier effect using wavelength interrogation. The experimental results show that the sensitivity reached 1,960 nm/RIU and 19,100 nm/RIU for sensors based on MZI alone and cascaded MZI-ring with Vernier effect, respectively. A biosensing application was also demonstrated by monitoring the interaction between goat and antigoat immunoglobulin G (IgG) pairs. This integrated high sensitivity biosensor has great potential for medical diagnostic applications.

  18. Sense data and the philosophy of mind: Russell, James, and Mach

    Directory of Open Access Journals (Sweden)

    Gary Hatfield

    2002-12-01

    Full Text Available The theory of knowledge in early twentieth-century Anglo American philosophy was oriented toward phenomenally described cognition There was a healthy respect for the mind body problem, which meant that phenomena in both the mental and physical domain were taken sinuously Bertrand Russell's developing position on sense-data and momentary particulars drew upon, and ultimately became like, the neutral monism of Ernst Mach and William James Due to a more recent behaviorist and physicalist inspired "fear of the mental", this development has been down played in historical work on early analytic philosophy Such neglect as sumes that the "linguistic turn" is a proper and permanent effect of twentieth century philosophy, an assumption that distorts early analytic historiography, and begs a substantive philosophical question about thought and cognition.

  19. Mach-Zehnder fiber-optic links for reaction history measurements at the National Ignition Facility

    Science.gov (United States)

    Miller, E. Kirk; Herrmann, H. W.; Stoeffl, W.; Horsfield, C. J.

    2010-08-01

    We present the details of the analog fiber-optic data link that will be used in the chamber-mounted Gamma Reaction History (GRH) diagnostic at the National Ignition Facility (NIF) located at the Lawrence Livermore Laboratory in Livermore, California. The system is based on Mach-Zehnder (MZ) modulators integrated into the diagnostic, with the source lasers and bias control electronics located remotely to protect the active electronics. A complete recording system for a single GRH channel comprises two MZ modulators, with the fiber signals split onto four channels on a single digitizer. By carefully selecting the attenuation, the photoreceiver, and the digitizer settings, the dynamic range achievable is greater than 1000:1 at the full system bandwidth of greater than 10 GHz. The system is designed to minimize electrical reflections and mitigate the effects of transient radiation darkening on the fibers.

  20. Vortex array laser beam generation from a Dove prism-embedded unbalanced Mach-Zehnder interferometer.

    Science.gov (United States)

    Chu, Shu-Chun; Yang, Chao-Shun; Otsuka, Kenju

    2008-11-24

    This paper proposes a new scheme for generating vortex laser beams from a laser. The proposed system consists of a Dove prism embedded in an unbalanced Mach-Zehnder interferometer configuration. This configuration allows controlled construction of p x p vortex array beams from Ince-Gaussian modes, IG(e) (p,p) modes. An incident IG(e)(p,p) laser beam of variety order p can easily be generated from an end-pumped solid-state laser system with an off-axis pumping mechanism. This study simulates this type of vortex array laser beam generation, analytically derives the vortex positions of the resulting vortex array laser beams, and discusses beam propagation effects. The resulting vortex array laser beam can be applied to optical tweezers and atom traps in the form of two-dimensional arrays, or used to study the transfer of angular momentum to micro particles or atoms (Bose-Einstein condensate).

  1. Electron acceleration in a nonrelativistic shock with very high Alfv\\'en Mach number

    CERN Document Server

    Matsumoto, Y; Hoshino, M

    2013-01-01

    Electron acceleration associated with various plasma kinetic instabilities in a nonrelativistic, very-high-Alfv\\'en Mach-number ($M_A \\sim 45$) shock is revealed by means of a two-dimensional fully kinetic PIC simulation. Electromagnetic (ion Weibel) and electrostatic (ion-acoustic and Buneman) instabilities are strongly activated at the same time in different regions of the two-dimensional shock structure. Relativistic electrons are quickly produced predominantly by the shock surfing mechanism with the Buneman instability at the leading edge of the foot. The energy spectrum has a high-energy tail exceeding the upstream ion kinetic energy accompanying the main thermal population. This gives a favorable condition for the ion acoustic instability at the shock front, which in turn results in additional energization. The large-amplitude ion Weibel instability generates current sheets in the foot, implying another dissipation mechanism via magnetic reconnection in a three-dimensional shock structure in the very-hi...

  2. 60 dB high-extinction auto-configured Mach-Zehnder interferometer

    Science.gov (United States)

    Wilkes, C. M.; Qiang, X.; Wang, J.; Santagati, R.; Paesani, S.; Zhou, X.; Miller, D. A. B.; Marshall, G. D.; Thompson, M. G.; O'Brien, J. L.

    2016-11-01

    Imperfections in integrated photonics manufacturing have a detrimental effect on the maximal achievable visibility in interferometric architectures. These limits have profound implications for further photonics technological developments and in particular for quantum photonics technologies. Active optimisation approaches, together with reconfigurable photonics, have been proposed as a solution to overcome this. In this paper, we demonstrate an ultra-high (>60 dB) extinction ratio in a silicon photonic device consisting of cascaded Mach-Zehnder interferometers, in which additional interferometers function as variable beamsplitters. The imperfections of fabricated beamsplitters are compensated using an automated progressive optimization algorithm with no requirement for pre-calibration. This work shows the possibility of integrating and accurately controlling linear-optical components for large-scale quantum information processing and other applications.

  3. Mach-zehnder based optical marker/comb generator for streak camera calibration

    Science.gov (United States)

    Miller, Edward Kirk

    2015-03-03

    This disclosure is directed to a method and apparatus for generating marker and comb indicia in an optical environment using a Mach-Zehnder (M-Z) modulator. High speed recording devices are configured to record image or other data defining a high speed event. To calibrate and establish time reference, the markers or combs are indicia which serve as timing pulses (markers) or a constant-frequency train of optical pulses (comb) to be imaged on a streak camera for accurate time based calibration and time reference. The system includes a camera, an optic signal generator which provides an optic signal to an M-Z modulator and biasing and modulation signal generators configured to provide input to the M-Z modulator. An optical reference signal is provided to the M-Z modulator. The M-Z modulator modulates the reference signal to a higher frequency optical signal which is output through a fiber coupled link to the streak camera.

  4. At the frontier of spacetime scalar-tensor theory, Bells inequality, Machs principle, exotic smoothness

    CERN Document Server

    Asselmeyer-Maluga, Torsten

    2016-01-01

    In this book, leading theorists present new contributions and reviews addressing longstanding challenges and ongoing progress in spacetime physics. In the anniversary year of Einstein's General Theory of Relativity, developed 100 years ago, this collection reflects the subsequent and continuing fruitful development of spacetime theories. The volume is published in honour of Carl Brans on the occasion of his 80th birthday. Carl H. Brans, who also contributes personally, is a creative and independent researcher and one of the founders of the scalar-tensor theory, also known as Jordan-Brans-Dicke theory. In the present book, much space is devoted to scalar-tensor theories. Since the beginning of the 1990s, Brans has worked on new models of spacetime, collectively known as exotic smoothness, a field largely established by him. In this Festschrift, one finds an outstanding and unique collection of articles about exotic smoothness. Also featured are Bell's inequality and Mach's principle. Personal memories and hist...

  5. SIERRA Low Mach Module: Fuego Theory Manual Version 4.44

    Energy Technology Data Exchange (ETDEWEB)

    Sierra Thermal/Fluid Team

    2017-04-01

    The SIERRA Low Mach Module: Fuego along with the SIERRA Participating Media Radiation Module: Syrinx, henceforth referred to as Fuego and Syrinx, respectively, are the key elements of the ASCI fire environment simulation project. The fire environment simulation project is directed at characterizing both open large-scale pool fires and building enclosure fires. Fuego represents the turbulent, buoyantly-driven incompressible flow, heat transfer, mass transfer, combustion, soot, and absorption coefficient model portion of the simulation software. Syrinx represents the participating-media thermal radiation mechanics. This project is an integral part of the SIERRA multi-mechanics software development project. Fuego depends heavily upon the core architecture developments provided by SIERRA for massively parallel computing, solution adaptivity, and mechanics coupling on unstructured grids.

  6. LDA measurements in a Mach 2 flow over a rearward facing step with staged transverse injection

    Science.gov (United States)

    Wang, J.-A.; Dancey, C. L.

    1992-01-01

    Measurements of the mean velocity field and selected turbulence statistics have been obtained via 2D LDA in a Mach 2 flow over a rearward facing step with downstream transverse injection. Axial mean velocity profiles, profiles of the axial and normal RMS levels, and the correlation coefficient between the axial and normal fluctuating components are presented for locations upstream of the step. These data, through comparison with other reported measurements in zero pressure gradient compressible boundary layers indicate that the boundary layers upstream of the step are consistent with 'quasi-equilibrium' turbulent boundary layers with the adiabatic wall boundary condition. Mean velocity field measurements on the symmetry plane of the tunnel are compared to laser induced iodine fluorescence measurements reported in the literature and obtained in the same facility. This comparison demonstrates the quality of the present LDA data set and shows that particle lag is not significant in the LDA measurements despite the complex nature of the downstream flow.

  7. Detailed Comparison of DNS to PSE for Oblique Breakdown at Mach 3

    Science.gov (United States)

    Mayer, Christian S. J.; Fasel, Hermann F.; Choudhari, Meelan; Chang, Chau-Lyan

    2010-01-01

    A pair of oblique waves at low amplitudes is introduced in a supersonic flat-plate boundary layer. Their downstream development and the concomitant process of laminar to turbulent transition is then investigated numerically using Direct Numerical Simulations (DNS) and Parabolized Stability Equations (PSE). This abstract is the last part of an extensive study of the complete transition process initiated by oblique breakdown at Mach 3. In contrast to the previous simulations, the symmetry condition in the spanwise direction is removed for the simulation presented in this abstract. By removing the symmetry condition, we are able to confirm that the flow is indeed symmetric over the entire computational domain. Asymmetric modes grow in the streamwise direction but reach only small amplitude values at the outflow. Furthermore, this abstract discusses new time-averaged data from our previous simulation CASE 3 and compares PSE data obtained from NASA's LASTRAC code to DNS results.

  8. Migrating the Mach-Zehnder chemical and bio-sensor to the mid-infrared region

    Science.gov (United States)

    Leidner, L.; Ewald, M.; Sieger, M.; Mizaikoff, B.; Gauglitz, G.

    2013-05-01

    The properties of integrated optical phase-modulated Mach-Zehnder interferometers (IO-MZI) are used to set up a new generation of chemical and biochemical sensors working in the mid-infrared. First applications of the MZI principle were introduced in the beginning 1990s. They range from a gas sensor to monitor organic solvent concentrations1 to setting up an immunoassay for the detection of the herbicide simazine2. Most if not all sensors of MZI type operate at wavelengths of the visible or near infrared spectrum. There are several reasons to change this strategy and move into the mid-infrared spectral range (MIR): higher manufacturing tolerances, increased evanescent field penetration depth, signal amplification by surface enhanced infrared absorption effect (SEIRA), species identification by MIR fingerprints. The basis of the planned MIR-MZI is a GaAs waveguide pattern epitaxially grown on a substrate3. As a first step towards nanostructuring the waveguide surface, chemical deposition of Au nanoparticles on GaAs transducers was established. For the use of MIR-MZI sensors in bioanalytical assay development, chemical immobilization of molecular recognition elements on GaAs transducers was carried out. The modified surfaces were characterized by atomic force microscopy (AFM), dark field microscopy, contact angle measurements and ellipsometric data as well as by a modified version of Reflectometric Interference Spectroscopy (RIfS)4. It was possible to monitor both the immobilization of gold nanoparticles and time-resolved specific binding using a model antibody antigen assay. After successful setup of relevant assays with RIfS, e.g. the detection of bacteria or endocrine disruptors, the assays are designed to be transferred onto the mid-infrared Mach-Zehnder interferometer.

  9. Gain Flattening Filter for Hybrid Sb-Doped EDFA Using All-Fiber Mach-Zehnder Interferometers

    Institute of Scientific and Technical Information of China (English)

    Manjung Han; Youngeun Im; Woojin Shin; Uh-Chan Ryu; K. Oh

    2003-01-01

    We demonstrate a novel gain-flattening filter based on all fiber Mach-Zehnder interferometers for Sb-doped silica hybrid EDFA. A gain flatness of better than 0.9dB has been achieved for three concatenated filters in C-band.

  10. High extinction ratio multiplexer/demultiplexer with a Mach-Zehnder interferometer and a fiber loop mirror

    Institute of Scientific and Technical Information of China (English)

    Yonglin Huang(黄勇林); Jie Li(李杰); Guiyun Kai(开桂云); Xiaoyi Dong(董孝义)

    2003-01-01

    A novel structure of high extinction ratio multiplexer/demultiplexer with a Mach-Zehnder interferometer (MZI) and a fiber loop mirror (FLM) is proposed. The experimental results show that the extinction ratio can be enhanced about two times in comparison with the conventional MZI.

  11. Resettling the Thoughts of Ernst Mach and the Vienna Circle in Europe: The Cases of Finland and Germany

    Science.gov (United States)

    Siemsen, Hayo; Siemsen, Karl Hayo

    2009-01-01

    Although it is generally assumed that the thoughts of Ernst Mach and the scientific fields he influenced (in this case psychophysics and "Gestalt" psychology) emigrated from Europe during Second World War they apparently survived in Finland, influencing the Finnish education system. The following article evaluates this relationship and its…

  12. Ultrafast optical reversible double Feynman logic gate using electro-optic effect in lithium-niobate based Mach Zehnder interferometers

    Science.gov (United States)

    Chauhan, Chanderkanta; Bedi, Amna; Kumar, Santosh

    2017-02-01

    In this ultra fast computing era power optimization is a major technological challenge that requires new computing paradigms. Conservative and reversible logic opens up the possibility of ultralow power computing. In this paper, basic reversible logic gate (double Feynman gate) using the lithium-niobate based Mach-Zehnder interferometer is proposed. The results are verified using beam propagation method and MATLAB simulations.

  13. Exploring the MACH Model's Potential as a Metacognitive Tool to Help Undergraduate Students Monitor Their Explanations of Biological Mechanisms

    Science.gov (United States)

    Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

    2016-01-01

    When undergraduate biology students learn to explain biological mechanisms, they face many challenges and may overestimate their understanding of living systems. Previously, we developed the MACH model of four components used by expert biologists to explain mechanisms: Methods, Analogies, Context, and How. This study explores the implementation of…

  14. Resettling the Thoughts of Ernst Mach and the Vienna Circle in Europe: The Cases of Finland and Germany

    Science.gov (United States)

    Siemsen, Hayo; Siemsen, Karl Hayo

    2009-01-01

    Although it is generally assumed that the thoughts of Ernst Mach and the scientific fields he influenced (in this case psychophysics and "Gestalt" psychology) emigrated from Europe during Second World War they apparently survived in Finland, influencing the Finnish education system. The following article evaluates this relationship and…

  15. Label-free detection in a lab-on-a-chip with a three-dimensional Mach-Zehnder interferometer

    NARCIS (Netherlands)

    Crespi, A.; Gu, Y.; Ngamson, B.; Dongre, C.; Hoekstra, H.J.W.M.; Vlekkert, van den H.H.; Watts, P.; Pollnau, M.; Cerullo, G.; Osellame, R.

    2010-01-01

    A Mach-Zehnder refractive index sensor is inscribed in a microfluidic lab-on-a-chip by exploiting the unique three-dimensional capabilities of femtosecond laser fabrication. This enables high sensitivity and spatially resolved label-free detection of biomolecules.

  16. Aerodynamic Characteristics of a Revised Target Drone Vehicle at Mach Numbers from 1.60 to 2.86

    Science.gov (United States)

    Blair, A. B., Jr.; Babb, C. Donald

    1968-01-01

    An investigation has been conducted in the Langley Unitary Plan wind tunnel to determine the aerodynamic characteristics of a revised target drone vehicle through a Mach number range from 1.60 to 2.86. The vehicle had canard surfaces and a swept clipped-delta wing with twin tip-mounted vertical tails.

  17. Boots on the Ground: Maryland

    Centers for Disease Control (CDC) Podcasts

    2013-10-24

    In this podcast, we talk to CDC public health advisor Artensie Flowers to see how her work with the Maryland State Health Department increases local health preparedness and response.  Created: 10/24/2013 by Office of Public Health Preparedness and Response (PHPR).   Date Released: 10/24/2013.

  18. FPGA Boot Loader and Scrubber

    Science.gov (United States)

    Wade, Randall S.; Jones, Bailey

    2009-01-01

    A computer program loads configuration code into a Xilinx field-programmable gate array (FPGA), reads back and verifies that code, reloads the code if an error is detected, and monitors the performance of the FPGA for errors in the presence of radiation. The program consists mainly of a set of VHDL files (wherein "VHDL" signifies "VHSIC Hardware Description Language" and "VHSIC" signifies "very-high-speed integrated circuit").

  19. Boot Camps for Charter Boards

    Science.gov (United States)

    Kronholz, June

    2015-01-01

    This article addresses the question of who owns the responsibility when a charter school gets into trouble--when its students aren't learning, or it misses its enrollment targets, or money runs short, or it closes. Upon presenting this question to a director of a charter school, a board member, and a Massachusetts-based education consultant and…

  20. Kansarme jongeren buiten de boot?

    Directory of Open Access Journals (Sweden)

    Ingrid Soffers

    2008-12-01

    Full Text Available In the Netherlands youth unemployment is an important issue on the political agenda. Projects have been set up to lead unemployed, often deprived young people back to school or work. However, not all of these youths want to participate in the projects and some leave early. Is this is a problem? Are these young people capable of finding employment by themselves or do their problems increase without the support of these projects? To answer these questions we studied deprived unemployed youths who belonged to the target group of an unemployment project (Route 23. The results of the research show that most of the former dropouts can look after themselves well. Many are working or are back at school, and they have fewer problems than they had before. Participants who left the project early are slightly less well off than the others. We advise monitoring all persons in the target group who fail to enter the project or leave early, and give them the opportunity to re-enter the project or ask for support. This is how the project can provide an additional safety net for these groups.

  1. Boots on the Ground: Arizona

    Centers for Disease Control (CDC) Podcasts

    2013-12-26

    In this podcast, we talk to CDC public health advisor Lisa Speissegger about her response efforts during the 2013 Arizona wildfires.  Created: 12/26/2013 by Office of Public Health Preparedness and Response (PHPR).   Date Released: 12/26/2013.

  2. Accelerated Drying of Wet Boots

    Science.gov (United States)

    2002-11-01

    in the field. Resume De nombreux documents sur les mat6riaux dits «( super absorbants >> traitent de la capacit6 de ces derniers A garder la peau ...chaussure contre la peau devient mouill~e A cause de l’eau qui entre de l’ext~rieur par le haut de la botte ou A travers la botte ou A cause de la... peau seche en pr6sence d’humidit6. Le polyacrylate de sodium est un de ces mat6riaux. Puisque de r6cents essais en conditions r6elles avec les soldats

  3. Ernst Mach and George Sarton's Successors: The Implicit Role Model of Teaching Science in USA and Elsewhere, Part II

    Science.gov (United States)

    Siemsen, Hayo

    2013-05-01

    George Sarton had a strong influence on modern history of science. The method he pursued throughout his life was the method he had discovered in Ernst Mach's Mechanics when he was a student in Ghent. Sarton was in fact throughout his life implementing a research program inspired by the epistemology of Mach. Sarton in turn inspired many others in several generations (James Conant, Thomas Kuhn, Gerald Holton, etc.). What were the origins of these ideas in Mach and what can this origin tell us about the history of science and science education nowadays? Which ideas proved to be successful and which ones need to be improved upon? The following article will elaborate the epistemological questions, which Charles Darwin's "Origin" raised concerning human knowledge and scientific knowledge and which led Mach to adapt the concept of what is "empirical" in contrast to metaphysical a priori assumptions a second time after Galileo. On this basis Sarton proposed "genesis and development" as the major goal of his journal Isis. Mach had elaborated this epistemology in La Connaissance et l'Erreur ( Knowledge and Error), which Sarton read in 1911 (Hiebert in Knowledge and error. Reidel, Dordrecht, 1976; de Mey in George Sarton centennial. Communication & Cognition, Ghent, pp. 3-6, 1984). Accordingly for Sarton, history becomes not only a subject of science, but a method of science education. Culture—and science as part of culture—is a result of a genetic process. History of science shapes and is shaped by science and science education in a reciprocal process. Its epistemology needs to be adapted to scientific facts and the philosophy of science. Sarton was well aware of the need to develop the history of science and the philosophy of science along the lines of this reciprocal process. It was a very fruitful basis, but a specific part of it Sarton did not elaborate further, namely the erkenntnis-theory and psychology of science education. This proved to be a crucial missing

  4. Results obtained during accelerated transonic tests of the Bell XS-1 airplane in flights to a Mach number of 0.92

    Science.gov (United States)

    Drake, Hubert M; Mclaughlin, Milton D; Goodman, Harold R

    1948-01-01

    Results are presented of tests up to a Mach number of 0.92 at altitudes around 30,000 feet. The data obtained show that the airplane can be flown to this Mach number above 30,000 feet. Longitudinal trim changes have been experienced but the forces involved have been small. The elevator effectiveness decreased about one-half with increase of Mach number from 0.70 to 0.87. Buffeting has been experienced in level flight but it has been mild and the associated tail loads have been small. No aileron buzz or other flutter phenomena have been noted.

  5. Optical directional coupler and Mach-Zehnder interferometer enhanced via 4H-SiC phonons

    Science.gov (United States)

    Finch, Michael F.; Saunders Filho, Claudio A. B.; Lail, Brian A.

    2016-09-01

    Surface phonon polaritons (SPhPs), similar to it cousin phenomenon surface plasmon polaitons (SPPs), are quasi-neutral particles resulting from light-matter coupling that can provide high modal confinement and long propagation in the mid to long infrared (IR). Mach-Zehnder interferometer (MZI) is a combination of two connected optical directional couplers (ODC). With the use of SPhPs, sub-wavelength feature sizes and modal areas can be achieved and to this end a hybrid SPhP waveguide, where propagation length and modal area can be trade-off, will be employed in the design of an ODC and MZI. This endeavor analyzes and characteristics both an ODC and MZI using commercially available numerical simulation software employing finite element method (FEM). The ODC and MZI are design using a novel SPhP hybrid waveguide design where a 4H-SiC substrate provides the polariton mode. The output ports power and relative phase difference between ports are investigated. SPhP enhanced ODC and MZI has applications including, but not limited to, next-generation ultra-compact photonic integrated circuits and waveguide based IR sensing.

  6. Some Clarifications on the Relation Between Bohmian Quantum Potential and Mach's Principle

    Science.gov (United States)

    Rahmani, Faramarz; Golshani, Mehdi

    2017-07-01

    Mach's principle asserts that the inertial mass of a body is related to the distribution of other distant bodies. This means that in the absence of other bodies, a single body has no mass. In this case, talking about motion is not possible, because the detection of motion is possible only relative to other bodies. But in physics we are faced with situations that are not fully Machian. As in the case of general theory of relativity where geodesics exist in the absence of any matter, the motion has meaning. Another example which is the main topic of our discussion, refers to Bohmian quantum mechanics, where the inertial mass of a single particle does not vanish, but is modified. We can call such situations in which motion or mass of a single particle has meaning, pseudo-Machian situations. In this paper, we use the Machian or pseudo-Machian considerations to clarify under what circumstances and how a Machian effect leads us to Bohmian quantum mechanics. Then, we shall get the Bohmian quantum potential and its higher order terms for the Klein-Gordon particle through Machian considerations, without using any quantum mechanical postulate or operator formalism.

  7. Design of all-optical multi-level regenerators based on Mach-Zehnder interferometer

    Science.gov (United States)

    Kong, Xiangjian; Wu, Baojian; Zhou, Xingyu; Wan, Qingyao; Jiang, Shanglong; Wen, Feng; Qiu, Kun

    2016-12-01

    We propose a design method for all-optical multi-level regenerators by mimicking the normalized power transfer function (PTF) in the first-order approximation to the ideal step-like PTF, in which a key step is to appropriately select the amplitude and phase conditions of Mach-Zehnder-interferometer (MZI)-based regenerators. As an example, we describe the design process of the self-phase-modulation (SPM)-based MZI regenerator constructed by a section of nonlinear fiber and an optical phase shifter (OPS). It is shown that the parameter of reference power level (RPL) can be regarded as the upper limit of input power, which is useful for the measure of the multi-level regeneration performance. The number of regenerative power levels increases with the RPL parameter. For 4-level pulse amplitude modulated (4PAM) optical signals degraded by the Gaussian noises with the standard deviation of 0.02, the SPM-based MZI regenerator has an average noise reduction ratio (NRR) of 6.5 dB, better than that of 1st-order regenerator by about 5 dB.

  8. An innovative single development process for integrated optical Mach-Zehnder interferometer pattern transfer

    Science.gov (United States)

    Idris, NurulBariah; Lau, Kuen Yau; Khor, Kang Nan; Abdul Wahid, Mohamad Halim; Ahmad Hambali, Nor Azura Malini; Retnasamy, Vithyacharan; Mohamad Shahimin, Mukhzeer

    2017-02-01

    Integrated optical Mach-Zehnder interferometer (IO-MZI) has been widely researched for various usage including for biosensor application. However, the success rate of IO-MZI pattern transfer has been low using the conventional multidevelopment process. One of the main factors is the particle contamination due to the practice of reused developer bath. In this work, an innovative single development process had been proposed with the utilization of the same conventional set-up but with a different protocol. The concept of this method is the estimation of total development time based on the calculated development rate. By doing so, the development process can be completed with only one immersion of the substrate in the developer bath. Besides, the manipulation of development rate by varying exposure time in this work also had revealed the possibility of manipulation of line-width based on the exposure time. In short, the proposed single development process has increased the success rate of IO-MZI pattern transfer from 30% (multi-development method) to 90%.

  9. A Mach-Zehnder interferometer based on orbital angular momentum for improved vortex coronagraph efficiency

    CERN Document Server

    Piron, P; Huby, E; Mawet, D; Ruane, M Karlsson ad G; Habraken, S; Absil, O; Surdej, J

    2016-01-01

    The Annular Groove Phase Mask (AGPM) is a vectorial vortex phase mask. It acts as a half-wave plate with a radial fast axis orientation operating in the mid infrared domain. When placed at the focus of a telescope element provides a continuous helical phase ramp for an on axis sources, which creates the orbital angular momentum. Thanks to that phase, the intensity of the central source is canceled by a down-stream pupil stop, while the off axis sources are not affected. However due to experimental conditions the nulling is hardly perfect. To improve the null, a Mach-Zehnder interferometer containing Dove prisms differently oriented can be proposed to sort out light based on its orbital angular momentum (OAM). Thanks to the differential rotation of the beam, a {\\pi} phase shift is achieved for the on axis light affected by a non zero OAM. Therefore the contrast between the star and its faint companion is enhanced. Nevertheless, due the Dove prisms birefringence, the performance of the interferometer is relativ...

  10. Optimization design of optical waveguide in Mach-Zehnder electro-optical polymer modulator

    Institute of Scientific and Technical Information of China (English)

    GAO Yuan; ZHANG Xiao-xia; LIAO Jin-kun

    2011-01-01

    @@ In order to reduce transmission loss of the optical waveguide in Mach-Zehnder (M-Z) electro-optical (EO) polymer modulator,the basic iterative formula of semi-vector finite-difference beam propagation method (FD-BPM) is obtained from the scalar wave equation.The transition waveguide is combined with S-type bend branch waveguide for the M-Z EO modulator in the branch waveguide.The effects of structure parameters such as ridge width, length of the branch waveguide and interferometer spacing on the transmission loss are systematically studied by using the semi-vector FD-BPM method.The structure is optimized as an S-sine bend branch waveguide, with rib width w=7 μm, length of branch waveguide L=1200μm and interferometer spacing G=22 μm.The results show that the optimized structure can reduce transmission loss to 0.083 dB,which have a certain reference value to the design of optical waveguide in M-Z polymer modulator.

  11. Unsteadiness of a shock train in Mach 2.0 flow

    Science.gov (United States)

    Hunt, Robin; Driscoll, James; Gamba, Mirko

    2016-11-01

    Experimental observations of the progression of flow unsteadiness within a shock train are presented. A downstream control valve is used to generate a shock train in the constant area test section of a wind tunnel with a freestream Mach number of 2.0. Even with nominally constant boundary conditions the shock train exhibits inherent unsteady motion about the time average position. At the conditions presented the shocks can be displaced by up to 0.35 duct heights. Better knowledge of the shock train's dynamics may allow us to introduce control algorithms to reduce the system's unsteadiness and thus minimize the associated mechanical and thermal loads. An edge detection algorithm is applied to the instantaneous frames of high speed Schlieren movies to track the location of morphological features within the shock system. Simultaneously, high speed pressure transducers record the pressure fluctuations along the bottom wall of the duct. The results indicate a complex frequency dependent dynamical system. A strong component of the dynamics involves a disturbance traveling upstream through the boundary layer. Once the disturbance reaches the leading shock foot the shocks respond in order with the most upstream shock moving first.

  12. Rescaling of the Roe scheme in low Mach-number flow regions

    Science.gov (United States)

    Boniface, Jean-Christophe

    2017-01-01

    A rescaled matrix-valued dissipation is reformulated for the Roe scheme in low Mach-number flow regions from a well known family of local low-speed preconditioners popularized by Turkel. The rescaling is obtained explicitly by suppressing the pre-multiplication of the preconditioner with the time derivative and by deriving the full set of eigenspaces of the Roe-Turkel matrix dissipation. This formulation preserves the time consistency and does not require to reformulate the boundary conditions based on the characteristic theory. The dissipation matrix achieves by construction the proper scaling in low-speed flow regions and returns the original Roe scheme at the sonic line. We find that all eigenvalues are nonnegative in the subsonic regime. However, it becomes necessary to formulate a stringent stability condition to the explicit scheme in the low-speed flow regions based on the spectral radius of the rescaled matrix dissipation. With the large disparity of the eigenvalues in the dissipation matrix, this formulation raises a two-timescale problem for the acoustic waves, which is circumvented for a steady-state iterative procedure by the development of a robust implicit characteristic matrix time-stepping scheme. The behaviour of the modified eigenvalues in the incompressible limit and at the sonic line also suggests applying the entropy correction carefully, especially for complex non-linear flows.

  13. Silicon photonics athermal Mach-Zehnder interferometer with wide thermal and spectral operating range

    Science.gov (United States)

    Xing, Peng; Viegas, Jaime

    2015-02-01

    In the context of 3D-integrated circuit (3DIC) integration of photonic and electronic components on vertical stacks covering different domains (digital, analog, RF, optical and MEMS), the control and minimization of adverse thermal effects on the behavior of the different parts of the microsystem is a major concern. Solutions based on passive athermal design are good candidates for enabling operation of optical components over electronic ICs with variable temporal and spatial thermal load while at the same time, minimizing energy loss on thermal biasing resistive loads. In this work, an improved athermal design method and the corresponding validating fabricated prototype are presented with the aim of extending the spectral athermal operating range of a Mach-Zehnder interferometer (MZI) over a wide thermal range with minimal temperature sensitivity. The proposed approach is demonstrated with a CMOS compatible silicon-on-insulator process flow fabrication run. The fabricated MZIs have a temperature sensitivity of around 20 pm/K over a spectral range larger than 60 nm for operating temperatures in the range of 20°C to 60°C. These devices are suitable for future optical and electronic 3D IC integration.

  14. Anomalous flow deflection at planetary bow shocks in the low Alfven Mach number regime

    Science.gov (United States)

    Nishino, Masaki N.; Fujimoto, Masaki; Tai, Phan-Duc; Mukai, Toshifumi; Saito, Yoshifumi; Kuznetsova, Masha M.; Rastaetter, Lutz

    A planetary magnetosphere is an obstacle to the super-sonic solar wind and the bow shock is formed in the front-side of it. In ordinary hydro-dynamics, the flow decelerated at the shock is diverted around the obstacle symmetrically about the planet-Sun line, which is indeed observed in the magnetosheath most of the time. Here we show a case under a very low density solar wind in which duskward flow was observed in the dawnside magnetosheath of the Earth's magnetosphere. A Rankine-Hugoniot test across the bow shock shows that the magnetic effect is crucial for this "wrong flow" to appear. A full three-dimensional Magneto- Hydro-Dynamics (MHD) simulation of the situation in this previously unexplored parameter regime is also performed. It is illustrated that in addition to the "wrong flow" feature, various peculiar characteristics appear in the global picture of the MHD flow interaction with the obstacle. The magnetic effect at the bow shock should become more conspicuously around the Mercury's magnetosphere, because stronger interplanetary magnetic field and slower solar wind around the Mercury let the Alfven Mach number low. Resultant strong deformation of the magnetosphere induced by the "wrong flow" will cause more complex interaction between the solar wind and the Mercury.

  15. Transition in oblique shock/boundary layer interactions at Mach 5.92

    Science.gov (United States)

    Dwivedi, Anubhav; Shrestha, Prakash; Hildebrand, Nathaniel; Nichols, J. W.; Jovanovic, M. R.; Candler, G. V.

    2016-11-01

    We use the compressible flow solver US3D to perform DNS of an oblique shock wave interacting with a laminar boundary layer over an adiabatic flat plate at Mach 5 . 92 . Simulations are repeated with different spanwise extents. The adverse pressure gradient created by the shock causes the boundary layer to separate, leading to the formation of a recirculation bubble downstream. We consider interactions of various strengths by varying the shock angle. A sufficiently strong interaction causes the flow to become 3 - D , unsteady and eventually transition to turbulence. We observe long streamwise streaks downstream of the reattachment point which eventually break into turbulence. In the present work, we characterize the spatio-temporal dynamics of the unsteady separation bubble and these streaks using Fourier analysis and Sparsity Promoting Dynamic Mode Decomposition. To investigate the origin of these streaks we also analyze the role of linear Görtler instability resulting from the curvature of the streamlines induced by the separation bubble. Supported by ONR, Grant No. N00014-15-1-2522.

  16. Modeling plasma glow discharges in Air near a Mach 3 bow shock with KRONOS

    Science.gov (United States)

    Rassou, Sebastien; Labaune, Julien; Packan, Denis; Elias, Paul-Quentin

    2016-09-01

    In this work, plasma glow discharge in Air is modeled near a Mach 3 bow shock. Numerical simulations are performed using the coupling KRONOS which have been developed at ONERA. The flow field is modeled using the code CFD: CEDRE from ONERA and the electrical and plasma part by the EDF open-source code CODE_SATURNE. The plasma kinetic modeling consists on a two-term Boltzmann equation solver and a chemical reaction solver depending of the electric field. The coupling KRONOS is fully parallelized and run on ONERA supercomputers. The shock wave is formed by the propagation of a supersonic flow (M = 3) through a truncated conical model mounted with a central spike. Depending on the spike's voltage value, corona, glow or arc regime could be obtained in a steady flow. The parameters for the supersonic flow and the spike configurations are chosen to be in glow discharge regime and to reproduce the experimental setup. In our simulations, 12 species and 80 reactions (ionization, electronic or vibrational excitation, attachment etc ...) are considered to properly model the glow discharge and the afterglow. In a stationary flow, glow discharge is observed only at the upstream of the shock wave near the high voltage spike. Behind the bow shock, in the afterglow, negative ions are provided by electrons attachment with O2. The negative ions flow convection ensures the electrical conduction and the establishment of the glow discharge.

  17. Photonic crystal fiber Mach-Zehnder interferometer for refractive index sensing.

    Science.gov (United States)

    Wang, Jian-Neng; Tang, Jaw-Luen

    2012-01-01

    We report on a refractive index sensor using a photonic crystal fiber (PCF) interferometer which was realized by fusion splicing a short section of PCF (Blaze Photonics, LMA-10) between two standard single mode fibers. The fully collapsed air holes of the PCF at the spice regions allow the coupling of PCF core and cladding modes that makes a Mach-Zehnder interferometer. The transmission spectrum exhibits sinusoidal interference pattern which shifts differently when the cladding/core surface of the PCF is immersed with different RI of the surrounding medium. Experimental results using wavelength-shift interrogation for sensing different concentrations of sucrose solution show that a resolution of 1.62 × 10(-4)-8.88 × 10(-4) RIU or 1.02 × 10(-4)-9.04 × 10(-4) RIU (sensing length for 3.50 or 5.00 cm, respectively) was achieved for refractive indices in the range of 1.333 to 1.422, suggesting that the PCF interferometer are attractive for chemical, biological, biochemical sensing with aqueous solutions, as well as for civil engineering and environmental monitoring applications.

  18. Background-oriented schlieren imaging of flow around a circular cylinder at low Mach numbers

    Science.gov (United States)

    Stadler, Hannes; Bauknecht, André; Siegrist, Silvan; Flesch, Robert; Wolf, C. Christian; van Hinsberg, Nils; Jacobs, Markus

    2017-09-01

    The background-oriented schlieren (BOS) imaging method has, for the first time, been applied in the investigation of the flow around a circular cylinder at low Mach numbers (Mnumbers of 0.1× 10^6 ≤ Re ≤ 6.0× 10^6. Even at ambient pressure and the lowest Reynolds number investigated, density gradients associated with the flow around the cylinder were recorded. The signal-to-noise ratio of the evaluated gradient field improved with increasing stagnation pressure. The separation point could easily be identified with this non-intrusive measurement technique and corresponds well to simultaneous surface pressure measurements. The resulting displacement field is in principle of qualitative nature as the observation angle was parallel to the cylinder axis only in a single point of the recorded images. However, it has been possible to integrate the density field along the surface of the cylinder by successive imaging at incremental angular positions around the cylinder. This density distribution has been found to agree well with the pressure measurements and with potential theory where appropriate.

  19. Silicon photonic Mach Zehnder modulators for next-generation short-reach optical communication networks

    Science.gov (United States)

    Lacava, C.; Liu, Z.; Thomson, D.; Ke, Li; Fedeli, J. M.; Richardson, D. J.; Reed, G. T.; Petropoulos, P.

    2016-02-01

    Communication traffic grows relentlessly in today's networks, and with ever more machines connected to the network, this trend is set to continue for the foreseeable future. It is widely accepted that increasingly faster communications are required at the point of the end users, and consequently optical transmission plays a progressively greater role even in short- and medium-reach networks. Silicon photonic technologies are becoming increasingly attractive for such networks, due to their potential for low cost, energetically efficient, high-speed optical components. A representative example is the silicon-based optical modulator, which has been actively studied. Researchers have demonstrated silicon modulators in different types of structures, such as ring resonators or slow light based devices. These approaches have shown remarkably good performance in terms of modulation efficiency, however their operation could be severely affected by temperature drifts or fabrication errors. Mach-Zehnder modulators (MZM), on the other hand, show good performance and resilience to different environmental conditions. In this paper we present a CMOS-compatible compact silicon MZM. We study the application of the modulator to short-reach interconnects by realizing data modulation using some relevant advanced modulation formats, such as 4-level Pulse Amplitude Modulation (PAM-4) and Discrete Multi-Tone (DMT) modulation and compare the performance of the different systems in transmission.

  20. Experimental study of crossflow instability on a Mach 6 yawed cone

    Science.gov (United States)

    Craig, Stuart; Saric, William

    2014-11-01

    Boundary-layer stability and transition represents a key challenge for the designer of hypersonic vehicles, which typically feature highly-swept and conical features inclined to the free stream. The transition process on each of these geometries is typically dominated by the three-dimensional crossflow instability. In order to advance the goal of a physics-based transition prediction method, crossflow experiments were undertaken in the Mach 6 Quiet Tunnel at Texas A&M University. Detailed boundary-layer measurements were performed on a 7-degree cone at a 6-degree angle of incidence using constant-temperature hot-wire anemometry (CTA) to produce boundary-layer contours at constant axial location. These contours illustrate the characteristic streamwise vortex pattern and mean-flow distortion characteristic of crossflow-dominated flows. Additionally, the high frequency response of the CTA system allows for analysis of the spectral content of the flow. These measurements show a high degree of qualitative agreement with analogous studies performed in low-speed flows.

  1. Mach-Zehnder modulator modulated radio-over-fiber transmission system using dual wavelength linearization

    Science.gov (United States)

    Zhu, Ran; Hui, Ming; Shen, Dongya; Zhang, Xiupu

    2017-02-01

    In this paper, dual wavelength linearization (DWL) technique is studied to suppress odd and even order nonlinearities simultaneously in a Mach-Zehnder modulator (MZM) modulated radio-over-fiber (RoF) transmission system. A theoretical model is given to analyze the DWL employed for MZM. In a single-tone test, the suppressions of the second order harmonic distortion (HD2) and third order harmonic distortion (HD3) at the same time are experimentally verified at different bias voltages of the MZM. The measured spurious-free dynamic ranges (SFDRs) with respect to the HD2 and HD3 are improved simultaneously compared to using a single laser. The output P1 dB is also improved by the DWL technique. Moreover, a WiFi signal is transmitted in the RoF system to test the linearization for broadband signal. The result shows that more than 1 dB improvement of the error vector magnitude (EVM) is obtained by the DWL technique.

  2. Investigation on Nyquist pulse generation using a single dual-parallel Mach-Zehnder modulator.

    Science.gov (United States)

    Wu, Jian; Zang, Jizhao; Li, Yan; Kong, Deming; Qiu, Jifang; Zhou, Siyuan; Shi, Jindan; Lin, Jintong

    2014-08-25

    The generation of Nyquist pulses with a dual parallel Mach-Zehnder modulator (DPMZM) driven by a single RF signal is demonstrated theoretically and experimentally. A complete theoretical analysis is developed and the limitation of the proposed scheme is also discussed. It is theoretically proved that Nyquist pulses with a spectrum of 5 flat comb lines can be generated using a single DPMZM, which is also verified with simulation. 7 flat comb lines in frequency domain can also be obtained if a large RF driving voltage is applied to DPMZM but the generated waveforms won't present a sinc-shape. This scheme is further investigated experimentally. 40 GHz Nyquist pulses with full-width-at-half-maximum (FWHM) less than 4.65 ps, signal-to-noise ratio (SNR) better than 29.5 dB, and normalized root-mean-square error (NRMSE) less than 2.4% are generated. It is found that a tradeoff exists between the insertion loss of the DPMZM and the deviation of generated pulses. The tunability of repetition rate is experimentally verified by generation of 1 GHz to 40 GHz Nyquist pulses with SNR better than 28.4 dB and NRMSE less than 6.15%.

  3. Some Clarifications on the Relation Between Bohmian Quantum Potential and Mach's Principle

    Science.gov (United States)

    Rahmani, Faramarz; Golshani, Mehdi

    2017-10-01

    Mach's principle asserts that the inertial mass of a body is related to the distribution of other distant bodies. This means that in the absence of other bodies, a single body has no mass. In this case, talking about motion is not possible, because the detection of motion is possible only relative to other bodies. But in physics we are faced with situations that are not fully Machian. As in the case of general theory of relativity where geodesics exist in the absence of any matter, the motion has meaning. Another example which is the main topic of our discussion, refers to Bohmian quantum mechanics, where the inertial mass of a single particle does not vanish, but is modified. We can call such situations in which motion or mass of a single particle has meaning, pseudo-Machian situations. In this paper, we use the Machian or pseudo-Machian considerations to clarify under what circumstances and how a Machian effect leads us to Bohmian quantum mechanics. Then, we shall get the Bohmian quantum potential and its higher order terms for the Klein-Gordon particle through Machian considerations, without using any quantum mechanical postulate or operator formalism.

  4. Effects of Fin Leading Edge Sweep on Shock-Shock Interaction at Mach 6

    Science.gov (United States)

    Berry, Scott A.; Nowak, Robert J.

    1996-01-01

    The effects of fin leading edge sweep on peak heating rates due to shock-shock interaction have been experimentally examined in the Langley 20-Inch Mach 6 Tunnel. The shock interaction was produced by the intersection of a planar incident shock (16.8 deg shock angle relative to the freestream, generated by a 9 deg wedge) with the bow shock formed around a O.5-inch diameter cylindrical leading edge fin. Heating distributions along the leading edge stagnation line have been obtained using densely spaced thin film resistive-type sensors. Schlieren images were obtained to illustrate the very complex shock-shock interactions. The fin leading edge sweep angle was varied from 15-degrees swept back to 45-degrees swept forward for a freestream unit Reynolds number of 2 x 10(exp 6)/ft. Two models were utilized during the study, one with 0.025-inch spacing between gage centers, and the other 0.015-inch spacing. Gage spatial resolution on the order of 0.015-in appeared to accurately capture the narrow spike in heating. Peak heating due to shock interaction was maximized when the fin was swept forward 15 deg and 25 deg, both promoting augmentations about 7 times the baseline value. The schlieren images for these cases revealed Type 4 and Type 3 interactions, respectively.

  5. Biosensors based on Si3N4 asymmetric Mach-Zehnder interferometers

    Science.gov (United States)

    Chalyan, Tatevik; Pasquardini, Laura; Falke, Floris; Zanetti, Manuela; Guider, Romain; Gandolfi, Davide; Schreuder, Eric; Pederzolli, Cecilia; Heideman, René G.; Pavesi, Lorenzo

    2016-04-01

    In this work, we present a study on photonic biosensors based on Si3N4 asymmetric Mach-Zehnder Interferometers (aMZI) for Aflatoxin M1 (AFM1) detection. AFM1 is an hepatotoxic and a carcinogenic toxin present in milk. The biosensor is based on an array of four Si3N4 aMZI that are optimized for 850nm wavelength. We measure the bulk Sensitivity (S) and the Limit of Detection (LOD) of our devices. In the array, three devices are exposed and have very similar sensitivities. The fourth aMZI, which is covered by SiO2, is used as an internal reference for laser (a VCSEL) and temperature fluctuations. We measured a phase sensitivity of 14300+/-400 rad/RIU. To characterize the LOD of the sensors, we measure the uncertainty of the experimental readout system. From the measurements on three aMZI, we observe the same value of LOD, which is ≍ 4.5×10-7 RIU. After the sensor characterization on homogeneous sensing, we test the surface sensing performances by flowing specific Aflatoxin M1 and non-specific Ochratoxin in 50 mM MES pH 6.6 buffer on the top of the sensors functionalized with Antigen-Recognising Fragments (Fab'). The difference between specific and non-specific signals shows the specificity of our sensors. A moderate regeneration of the sensors is obtained by using glycine solution.

  6. Tunable Photonic Crystal Mach-Zehnder Interferometer Based on Self-collimation Effect

    Institute of Scientific and Technical Information of China (English)

    CHEN Xi-Yao; LI Hui; QIU Yi-Shen; WANG Yu-Fei; NI Bo

    2008-01-01

    @@ A theoretical model for tunable Mach-Zehnder interferometers (TMZIs) constructed in a two-dimensional pho-tonic crystal (2D PhC) is proposed.The 2D PhC consists of a square lattice of cylindric air holes in silicon.The TMZI includes two mirrors and two splitters.Light propagates between them employing a sell-collimation effect.The two interferometer branches have different path lengths.Parts of the longer branch are infiltrated with a kind of liquid crystal (LC) with ordinary and extraordinary refractive indices 1.522 and I.706, respectively.The transmission spectra at two TMZI output ports are in the shape of sinusoidal carves and have a uniform peak spacing 0.0017c/a in the frequency range from 0.26c/a to 0.27c/a.When the effective refractive index neff of the liquid crystal is increased from 1.522 to 1.706, the peaks shift to the lower frequencies over 0.0017c/a while the peak spacing is almost kept unchanged.Thus this TMZI can work as a tunable power splitter or an optical switch.For the central operating wavelength around 1550nm, its dimensions are only about tens of micron.Thus this device may be applied to photonic integrated circuits.

  7. Boundary-layer transition on blunt slender cones at Mach 10

    Science.gov (United States)

    Bell, R. L.

    1984-08-01

    Investigations of the effects of nose blunting on the location of boundary-layer transition on slender cones at supersonic or hypersonic speeds so back 25 years. For some time it was thought that the movement of the transition point was simply due to the reduction in local Reynolds number associated with the loss in total pressure through the bow shock. More recently, it has been shown that variations in the local transition Reynolds number also occur on a blunt cone and that both these effects must be taken into account in explaining the observed movement in transition along the cone frustum. The present investigation was carried out as a demonstration test for the development of a new capability in Hypervelocity Tunnel 9 at the Naval Surface Weapon Center. The objective of this development effort was to raise the Reynolds number at mach 10 from about 5 x 1000000 per foot to 20 x 1000000 per foot. This was done so that naturally turbulent boundary layers (i.e., without tripping) could be obtained on R/V models. Thus an investigation of boundary layer transition was an appropriate choice for the demonstration test.

  8. Temperature sensing setup based on an aluminum coated Mach-Zehnder Interferometer

    Science.gov (United States)

    Pacheco-Chacón, Eliana I.; Gallegos-Arellano, E.; Sierra-Hernandez, Juan M.; Rojas-Laguna, Roberto; Estudillo-Ayala, Julian M.; Hernandez, Emmanuel; Jauregui-Vazquez, D.; Hernandez-Garcia, J. C.

    2017-05-01

    In this paper a temperature sensing setup based on a Photonic Crystal Fiber (PCF) Mach-Zehnder Interferometer (MZI), coated with aluminum is proposed. Here, this interferometer is fabricated through the concatenation of two sections of Single Mode Fiber (SMF) with a segment of PCF between them. The SMF-PCF joint acts as beam splitter causing the excitement of PCF's, both cladding and fundamental core modes. In the PCF-SMF union, the cladding modes couple again to the core of the SMF, and interfere with the fundamental core mode, this interaction results in an interference pattern spectrum. Moreover, the MZI was coated with aluminum, using the evaporation technique. By adding a thin metal layer to the PCF section, the general thermal coefficient of the structure changes, enhancing the sensitivity of the device. Experimental results show that a visibility of 13 dBm can be obtained and a sensitivity of 250 pm/°C. Finally, the proposed structure is simple, cost effective and easy to fabricate.

  9. Receptivity of Boundary Layer over a Blunt Wedge due to Freestream Pulse Disturbances at Mach 6

    Directory of Open Access Journals (Sweden)

    Jianqiang Shi

    2016-01-01

    Full Text Available Direct numerical simulation (DNS of a hypersonic compressible flow over a blunt wedge with fast acoustic disturbances in freestream is performed. The receptivity characteristics of boundary layer to freestream pulse acoustic disturbances are numerically investigated at Mach 6, and the frequency effects of freestream pulse wave on boundary layer receptivity are discussed. Results show that there are several main disturbance mode clusters in boundary layer under acoustic pulse wave, and the number of main disturbance clusters decreases along the streamwise. As disturbance wave propagates from upstream to downstream direction, the component of the modes below fundamental frequency decreases, and the component of the modes above second harmonic components increases quickly in general. There are competition and disturbance energy transfer between different boundary layer modes. The nose boundary layer is dominated by the nearby mode of fundamental frequency. The number of the main disturbance mode clusters decreases as the freestream disturbance frequency increases. The frequency range with larger growth narrows along the streamwise. In general, the amplitudes of both fundamental mode and harmonics become larger with the decreasing of freestream disturbance frequency. High frequency freestream disturbance accelerates the decay of disturbance wave in downstream boundary layer.

  10. Stochastic dual-plane on-axis digital holography based on Mach-Zehnder interferometer

    Science.gov (United States)

    Wang, Fengpeng; Wang, Dayong; Rong, Lu; Wang, Yunxin; Zhao, Jie

    2016-09-01

    For traditional dual-plane on-axis digital holography, the robustness is lower because it is difficult to maintain the stability of the phase difference between the object beam and the reference beam, and it may be invalid when the objects are on the surface of a medium with uneven thickness. An improved dual-plane digital holographic method based on Mach-Zehnder interferometer is presented to address these problems. Two holograms are recorded at two different planes separated by a small distance. Then, the zero-order image and conjugated image are eliminated by Fourier domain processing. In order to enhance the robustness of the system, the object is illuminated by a stochastic beam that is a speckle wave produced by a diffuser. Simulated and experimental results are shown to demonstrate that the proposed method has greater robustness than the traditional dual-plane on-axis digital holography and it can be used to imaging on the irregular surface of a transparent medium.

  11. Microfiber Mach-Zehnder interferometer based on long period grating for sensing applications.

    Science.gov (United States)

    Tan, Yanzhen; Sun, Li-Peng; Jin, Long; Li, Jie; Guan, Bai-Ou

    2013-01-14

    A Mach-Zehnder interferometer (MZI) composed by a pair of long period gratings (LPGs) fabricated in silica microfiber for sensing applications is demonstrated. Each LPG is fabricated with a pulsed CO2 laser by creating six periodical deformations along fiber length with only one scanning cycle. The length of the MZI can reach as short as 8.84 mm when the diameter of the microfiber is 9.5 μm. Compared with the ones fabricated in single-mode fibers, the present MZI is much shorter owing to the large effective-index difference between the fundamental and higher order modes. The microfiber MZI exhibits a sensitivity to surrounding refractive index (RI) of 2225 nm per refractive index unit and the temperature sensitivity of only 11.7 pm/°C. Theoretical analysis suggests that the performances of the MZI sensor can be improved by using thinner microfibers with a diameter down to 3.5 μm: The sensitivity can be greatly enhanced due to the stronger evanescent-field interaction and reduced dispersion factor; the transmission dips become narrower which benefits high-resolution measurement; the thinner fiber also allows further reduction in device length. The present device has great potential in biochemical and medical sensing due to the advantages including easy fabrication, excellent compactness and high sensitivity.

  12. High accuracy microwave frequency measurement based on single-drive dual-parallel Mach-Zehnder modulator

    DEFF Research Database (Denmark)

    Zhao, Ying; Pang, Xiaodan; Deng, Lei

    2011-01-01

    A novel approach for broadband microwave frequency measurement by employing a single-drive dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. Based on bias manipulations of the modulator, conventional frequency-to-power mapping technique is developed by performing a...... 10−3 relative error. This high accuracy frequency measurement technique is a promising candidate for high-speed electronic warfare and defense applications.......A novel approach for broadband microwave frequency measurement by employing a single-drive dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. Based on bias manipulations of the modulator, conventional frequency-to-power mapping technique is developed by performing...... a two-stage frequency measurement cooperating with digital signal processing. In the experiment, 10GHz measurement range is guaranteed and the average uncertainty of estimated microwave frequency is 5.4MHz, which verifies the measurement accuracy is significantly improved by achieving an unprecedented...

  13. Measurement of the speed of sound by observation of the Mach cones in a complex plasma under microgravity conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zhukhovitskii, D. I., E-mail: dmr@ihed.ras.ru; Fortov, V. E.; Molotkov, V. I.; Lipaev, A. M.; Naumkin, V. N. [Joint Institute of High Temperatures, Russian Academy of Sciences, Izhorskaya 13, Bd. 2, 125412 Moscow (Russian Federation); Thomas, H. M. [Research Group Complex Plasma, DLR, Oberpfaffenhofen, 82234 Wessling (Germany); Ivlev, A. V.; Morfill, G. E. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, 85748 Garching (Germany); Schwabe, M. [Department of Chemical and Biomolecular Engineering, Graves Lab, D75 Tan Hall, University of California, Berkeley, CA 94720 (United States)

    2015-02-15

    We report the first observation of the Mach cones excited by a larger microparticle (projectile) moving through a cloud of smaller microparticles (dust) in a complex plasma with neon as a buffer gas under microgravity conditions. A collective motion of the dust particles occurs as propagation of the contact discontinuity. The corresponding speed of sound was measured by a special method of the Mach cone visualization. The measurement results are incompatible with the theory of ion acoustic waves. The estimate for the pressure in a strongly coupled Coulomb system and a scaling law for the complex plasma make it possible to derive an evaluation for the speed of sound, which is in a reasonable agreement with the experiments in complex plasmas.

  14. Generation and Evolution of High-Mach Number, Laser-Driven Magnetized Collisionless Shocks in the Laboratory

    CERN Document Server

    Schaeffer, Derek; Haberberger, Dan; Fiksel, Gennady; Bhattacharjee, Amitava; Barnak, Daniel; Hu, Suxing; Germaschewski, Kai

    2016-01-01

    Shocks act to convert incoming supersonic flows to heat, and in collisionless plasmas the shock layer forms on kinetic plasma scales through collective electromagnetic effects. These collisionless shocks have been observed in many space and astrophysical systems [Smith 1975, Smith 1980, Burlaga 2008, Sulaiman 2015], and are believed to accelerate particles, including cosmic rays, to extremely high energies [Kazanas 1986, Loeb 2000, Bamba 2003, Masters 2013, Ackermann 2013]. Of particular importance are the class of high-Mach number, supercritical shocks [Balogh 2013] ($M_A\\gtrsim4$), which must reflect significant numbers of particles back into the upstream to accommodate entropy production, and in doing so seed proposed particle acceleration mechanisms [Blandford 1978, McClements 2001, Caprioli 2014, Matsumoto 2015]. Here we present the first laboratory generation of high-Mach number magnetized collisionless shocks created through the interaction of an expanding laser-driven plasma with a magnetized ambient ...

  15. Hybrid InGaAsP-InP Mach-Zehnder Racetrack Resonator for Thermooptic Switching and Coupling Control.

    Science.gov (United States)

    Green, William; Lee, Reginald; Derose, Guy; Scherer, Axel; Yariv, Amnon

    2005-03-07

    An InGaAsP-InP optical switch geometry based on electrical control of waveguide-resonator coupling is demonstrated. Thermooptic tuning of a Mach-Zehnder interferometer integrated with a racetrack resonator is shown to result in switching with ON-OFF contrast up to 18.5 dB. The optical characteristics of this unique design enable a substantial reduction of the switching power, to a value of 26 mW in comparison with 40 mW for a conventional Mach-Zehnder interferometer switch. Modulation response measurements reveal a 3 dB bandwidth of 400 kHz and a rise time of 1.8 micros, comparing favorably with current state-of-the-art thermooptic switches.

  16. Ultra-compact and temperature-insensitive Mach-Zehnder interferometer based on one multimode waveguide on silicon.

    Science.gov (United States)

    Yang, Huizhan; Zhang, Jianhao; Zhu, Yuntao; Zhou, Xuan; He, Sailing; Liu, Liu

    2017-02-01

    An ultra-compact and temperature-insensitive Mach-Zehnder interferometer device is introduced on the silicon-on-insulator platform. The device is constructed through one straight multimode waveguide, which consists of two densely packed silicon wires with a narrow gap of varying positions along the device. The total width of the proposed Mach-Zehnder interferometer is only about 1 μm. Interference patterns with extinction ratios of better than 20 dB are achieved. Temperature insensitive operation of the proposed device is also demonstrated for both global and local temperature changes. The shift rate of the wavelength response with respect to the substrate temperature change is within ±10  pm/K in a 30 nm wavelength range.

  17. High dynamic range microwave photonic down-conversion based on dual-parallel Mach-Zehnder modulator

    Science.gov (United States)

    Li, Hongli; Wang, Yunxin; Wang, Dayong; Rong, Lu; Jia, Yupeng; Li, Jingnan; Zhong, Xin; Yang, Dengcai; Zhou, Tao

    2016-10-01

    In order to enhance conversion efficiency and spurious free dynamic range of microwave photonic link, we present a microwave photonic down-conversion system based on an integrated dual-parallel Mach Zehnder modulator (DPMZM) and microwave photonic filter. The principle of frequency down conversion is analyzed. We demonstrate the conversion efficiency of system through theoretical derivation and simulation. The performance of the microwave photonic link is tested experimentally. It is found that the spurious free dynamic range of the proposed method is up to 102.5dB/Hz2/3 and the conversion efficiency is up to -22.01dB. The integrated dual-parallel Mach-Zehnder modulator link can serve as a good alternative to improve the conversion efficiency and spurious free dynamic range.

  18. Design of 1-bit and 2-bit magnitude comparators using electro-optic effect in Mach-Zehnder interferometers

    Science.gov (United States)

    Kumar, Santosh; Bisht, Ashish; Singh, Gurdeep; Choudhary, Kuldeep; Raina, K. K.; Amphawan, Angela

    2015-12-01

    The Mach-Zehnder interferometer (MZI) structures collectively show powerful capability in switching an input optical signal to a desired output port from a collection of output ports. Hence, it is possible to construct complex optical combinational digital circuits using the electro-optic effect constituting MZI structure as a basic building block. Optical switches have been designed for 1-bit and 2-bit magnitude comparators based on electro-optic effect using Mach-Zehnder interferometers. The paper constitutes a mathematical description of the proposed device and thereafter simulation using MATLAB. Analysis of some factors influencing the performances of proposed device has been discussed properly. The study is verified using beam propagation method.

  19. Measurement of the speed of sound by observation of the Mach cones in a complex plasma under microgravity conditions

    CERN Document Server

    Zhukhovitskii, D I; Molotkov, V I; Lipaev, A M; Naumkin, V N; Thomas, H M; Ivlev, A V; Schwabe, M; Morfill, G E

    2014-01-01

    We report the first observation of the Mach cones excited by a larger microparticle (projectile) moving through a cloud of smaller microparticles (dust) in a complex plasma with neon as a buffer gas under microgravity conditions. A collective motion of the dust particles occurs as propagation of the contact discontinuity. The corresponding speed of sound was measured by a special method of the Mach cone visualization. The measurement results are fully incompatible with the theory of ion acoustic waves. We explore the analogy between a strongly coupled Coulomb system and a solid. A scaling law for the complex plasma makes it possible to derive a theoretical estimate for the speed of sound, which is in a reasonable agreement with the experiments in strongly coupled complex plasmas.

  20. Radiation Hard Silicon Photonics Mach-Zehnder Modulator for HEP applications: all-Synopsys Sentaurus™ Pre-Irradiation Simulation

    CERN Document Server

    Cammarata, Simone

    2017-01-01

    Silicon Photonics may well provide the opportunity for new levels of integration between detectors and their readout electronics. This technology is thus being evaluated at CERN in order to assess its suitability for use in particle physics experiments. In order to check the agreement with measurements and the validity of previous device simulations, a pure Synopsys Sentaurus™ simulation of an un-irradiated Mach-Zehnder silicon modulator has been carried out during the Summer Student project.

  1. Mach-Zehnder Type Annealed Proton Exchange Waveguide and Coplanar Waveguide Modulation Electrode LiNbO3 Intensity Modulator

    Institute of Scientific and Technical Information of China (English)

    HE Jian; ZHU Xue-jun

    2007-01-01

    The characteristics of a conventional LiNbO3 intensity modulator made up of a Mach-Zehnder(MZ) type annealed proton exchange(APE) waveguide and coplanar waveguide(CPW) modulation electrode are presented. The APE waveguide characteristics and their relations with process parameters are analyzed. At the same time, the electrical characteristics of modulation electrode, such as modulation voltage, microwave effective index associated with modulation bandwidth, characteristics impedance, are also investigated in detail.

  2. 40-Gb/s star 16-QAM transmitter based on single dual-drive Mach-Zehnder modulator

    Institute of Scientific and Technical Information of China (English)

    Junming Gao; Xinyu Xu; Qingjiang Chang; Yikai Su

    2009-01-01

    We propose a 40-Gb/s star 16-ary quadrature amplitude modulation (16-QAM) transmitter using a single dual-drive Mach-Zehnder modulator (DDMZM). This transmitter is demonstrated through experiment and simulation and shows the advantage of simplicity for implementation. Simulation results indicate that error free performance could be achieved for the generated signal after 80-km standard single-mode fiber (SSMF) transmission with coherent detection scheme.

  3. Thermo-optic control of dielectric-loaded plasmonic Mach-Zehnder interferometers and directional coupler switches

    DEFF Research Database (Denmark)

    Gosciniak, J.; Markey, L.; Dereux, A.

    2012-01-01

    We report detailed experimental studies of compact fiber-coupled dielectric-loaded plasmonic waveguide components-Mach-Zehnder interferometers (MZIs) and directional couplers (DCs)-whose operation at telecom wavelengths is controlled via the thermo-optic effect by electrically heating the gold st......, and wavelength dependent low power (similar to 0.92 mW) rerouting is achieved with DC switches. Furthermore, simulations were performed to confirm the switching characteristics of the components....

  4. On-chip modulation for rotating sensing of gyroscope based on ring resonator coupled with Mach-Zehnder interferometer.

    Science.gov (United States)

    Zhang, Hao; Chen, Jiayang; Jin, Junjie; Lin, Jian; Zhao, Long; Bi, Zhuanfang; Huang, Anping; Xiao, Zhisong

    2016-01-01

    An improving structure for resonance optical gyro inserting a Mach-Zehnder Interferomete (MZI) into coupler region between ring resonator and straight waveguide was proposed. The different reference phase shift parameters in the MZI arms are tunable by thermo-optic effect and can be optimized at every rotation angular rate point without additional phase bias. Four optimum paths are formed to make the gyroscope to work always at the highest sensitivity.

  5. Heat transfer and pressure distributions on hemisphere-cylinders in methane-air combustion products at Mach 7

    Science.gov (United States)

    Weinstein, I.

    1973-01-01

    Heat-transfer and pressure distributions were measured over the surfaces of three hemisphere-cylinder models tested at a nominal Mach number of 7 in the Langley 8-foot high-temperature structures tunnel which uses methane-air products of combustion as a test medium. The results showed that the heat-transfer and pressure distributions over the surface of the models were in good agreement with experimental data obtained in air and also with theoretical predictions.

  6. Design and analysis of various multifunctional operations at ultrahigh speed by using a semiconductor optical amplifier-Mach-Zehnder interferometer

    Science.gov (United States)

    Lovkesh; Marwaha, Anupma

    2016-03-01

    Various multifunctional operations are performed by proposing designs of optical adder, subtractor, comparator, and decoder at 60 Gb/s. In all operations, constructive interference is produced by choosing optimized parameters, i.e., optical pulse generator power, input power, semiconductor optical amplifier-Mach-Zehnder interferometer parameters, and so on, for delivering a true output signal. An optical pulse-generated signal is required for all operations except addition, subtraction and equal to in a comparator.

  7. Characteristics of an add-drop filter composed of a Mach-Zehnder interferometer and double ring resonators

    Institute of Scientific and Technical Information of China (English)

    Fufei Pang; Xiuyou Han; Haiwen Cai; Ronghui Qu; Zujie Fang

    2005-01-01

    @@ A planar lightwave circuit (PLC) add-drop filter is proposed and analyzed, which consists of a symmetric Mach-Zehnder interferometer (MZI) combined with double microring resonators. A critical coupling condition is derived for a better box-like drop spectrum. Comparisons of its characteristics with other schemes,such as a MZI with a single ring resonator, are presented, and some of the issues about device design and fabrication are also discussed.

  8. Convective heat transfer studies at high temperatures with pressure gradient for inlet flow Mach number of 0.45

    Science.gov (United States)

    Pedrosa, A. C. F.; Nagamatsu, H. T.; Hinckel, J. A.

    1984-01-01

    Heat transfer measurements were determined for a flat plate with and without pressure gradient for various free stream temperatures, wall temperature ratios, and Reynolds numbers for an inlet flow Mach number of 0.45, which is a representative inlet Mach number for gas turbine rotor blades. A shock tube generated the high temperature and pressure air flow, and a variable geometry test section was used to produce inlet flow Mach number of 0.45 and accelerate the flow over the plate to sonic velocity. Thin-film platinum heat gages recorded the local heat flux for laminar, transition, and turbulent boundary layers. The free stream temperatures varied from 611 R (339 K) to 3840 R (2133 K) for a T(w)/T(r,g) temperature ratio of 0.87 to 0.14. The Reynolds number over the heat gages varied from 3000 to 690,000. The experimental heat transfer data were correlated with laminar and turbulent boundary layer theories for the range of temperatures and Reynolds numbers and the transition phenomenon was examined.

  9. Non-thermal Electron Acceleration in Low Mach Number Collisionless Shocks. I. Particle Energy Spectra and Acceleration Mechanism

    Science.gov (United States)

    Guo, Xinyi; Sironi, Lorenzo; Narayan, Ramesh

    2014-10-01

    Electron acceleration to non-thermal energies in low Mach number (Ms Diffusive shock acceleration, also known as first-order Fermi acceleration, cannot be directly invoked to explain the acceleration of electrons. Rather, an additional mechanism is required to pre-accelerate the electrons from thermal to supra-thermal energies, so they can then participate in the Fermi process. In this work, we use two- and three-dimensional particle-in-cell plasma simulations to study electron acceleration in low Mach number shocks. We focus on the particle energy spectra and the acceleration mechanism in a reference run with Ms = 3 and a quasi-perpendicular pre-shock magnetic field. We find that about 15% of the electrons can be efficiently accelerated, forming a non-thermal power-law tail in the energy spectrum with a slope of p ~= 2.4. Initially, thermal electrons are energized at the shock front via shock drift acceleration (SDA). The accelerated electrons are then reflected back upstream where their interaction with the incoming flow generates magnetic waves. In turn, the waves scatter the electrons propagating upstream back toward the shock for further energization via SDA. In summary, the self-generated waves allow for repeated cycles of SDA, similarly to a sustained Fermi-like process. This mechanism offers a natural solution to the conflict between the bright radio synchrotron emission observed from the outskirts of galaxy clusters and the low electron acceleration efficiency usually expected in low Mach number shocks.

  10. Analysis of U-Boot and Method of Its Porting on YLP2410 Platform%U-Boot分析与移植到YLP2410开发平台的方法

    Institute of Scientific and Technical Information of China (English)

    吴萌; 刘波

    2009-01-01

    以研究arm-linux嵌入式系统的基本方法、操作环境为目的,分析了引导程序Uboot的目录结构及移植过程中需主要修改的文件,结合自己的开发环境详细给出了Uboot-1.1.4在ylp2410开发板上具体的移植方法和步骤,包括环境的搭建、代码的添加位置、遇到的常见错误,且给出了一些具体的配置文件,最后将U-boot.bin文件下载到平台,运行稳定,通过测试.

  11. Exploring the MACH Model’s Potential as a Metacognitive Tool to Help Undergraduate Students Monitor Their Explanations of Biological Mechanisms

    Science.gov (United States)

    Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

    2016-01-01

    When undergraduate biology students learn to explain biological mechanisms, they face many challenges and may overestimate their understanding of living systems. Previously, we developed the MACH model of four components used by expert biologists to explain mechanisms: Methods, Analogies, Context, and How. This study explores the implementation of the model in an undergraduate biology classroom as an educational tool to address some of the known challenges. To find out how well students’ written explanations represent components of the MACH model before and after they were taught about it and why students think the MACH model was useful, we conducted an exploratory multiple case study with four interview participants. We characterize how two students explained biological mechanisms before and after a teaching intervention that used the MACH components. Inductive analysis of written explanations and interviews showed that MACH acted as an effective metacognitive tool for all four students by helping them to monitor their understanding, communicate explanations, and identify explanatory gaps. Further research, though, is needed to more fully substantiate the general usefulness of MACH for promoting students’ metacognition about their understanding of biological mechanisms. PMID:27252295

  12. Integrated all-polymer Mach-Zehnder interferometers without interaction window in asymmetric configuration

    Science.gov (United States)

    Xiao, Yanfen; Hofmann, Meike; Wang, Ziyu; Sherman, Stanislav; Li, Pei; Zappe, Hans

    2016-02-01

    Integrated Mach-Zehnder interferometers (MZI) based on semiconductors or glasses have been widely used as evanescent field sensors for the monitoring of liquid or gas concentrations. In these systems the upper cladding of the sensing arm is removed partially to form an interaction window by means of subtractive fabrication techniques like etching. The use of polymer materials implicates new options and challenges. Polymers are tunable in terms of refractive index and viscosity offering a great flexibility in design and fabrication in a certain range. They enable a cost-efficient and large-scale roll-to-roll manufacturing of integrated optics on flexible foils as substrate material. The foils can be pre-patterned for example by hot-embossing. Additive steps such as printing a pattern or dispensing a homogeneous layer of liquid monomer material followed by a UV induced polymerization can be used to define the optical structure. However, when a large scale fabrication is required, the reliable production of small lateral structures and thin layers is challenging. Thus the fabrication according to the classical MZI design including an interaction window is difficult so that new design approaches are required. We present here the design and systematic evaluation of MZI sensors without interaction window based on polymer materials. The phase shift at the recombining Y-splitter of the MZI upon a refractive index change of an analyte, which serves as upper cladding of the entire system, is generated by a geometrical asymmetricity of the MZI. The waveguides in the sensing and the reference arm have different width leading to different effective refractive indices and sensitivities. We consider theoretically the expected interference signal and show results from numerical simulations of the whole system using commercial software. The simulations include the material as well as propagation losses and give an overall optimal system length.

  13. Aerodynamic Performance and Static Stability and Control of Flat-Top Hypersonic Gliders at Mach Numbers from 0.6 to 18

    Science.gov (United States)

    Syvertson, Clarence A; Gloria, Hermilo R; Sarabia, Michael F

    1958-01-01

    A study is made of aerodynamic performance and static stability and control at hypersonic speeds. In a first part of the study, the effect of interference lift is investigated by tests of asymmetric models having conical fuselages and arrow plan-form wings. The fuselage of the asymmetric model is located entirely beneath the wing and has a semicircular cross section. The fuselage of the symmetric model was centrally located and has a circular cross section. Results are obtained for Mach numbers from 3 to 12 in part by application of the hypersonic similarity rule. These results show a maximum effect of interference on lift-drag ratio occurring at Mach number of 5, the Mach number at which the asymmetric model was designed to exploit favorable lift interference. At this Mach number, the asymmetric model is indicated to have a lift-drag ratio 11 percent higher than the symmetric model and 15 percent higher than the asymmetric model when inverted. These differences decrease to a few percent at a Mach number of 12. In the course of this part of the study, the accuracy to the hypersonic similarity rule applied to wing-body combinations is demonstrated with experimental results. These results indicate that the rule may prove useful for determining the aerodynamic characteristics of slender configurations at Mach numbers higher than those for which test equipment is really available. In a second part of the study, the aerodynamic performance and static stability and control characteristics of a hypersonic glider are investigated in somewhat greater detail. Results for Mach numbers from 3 to 18 for performance and 0.6 to 12 for stability and control are obtained by standard text techniques, by application of the hypersonic stability rule, and/or by use of helium as a test medium. Lift-drag ratios of about 5 for Mach numbers up to 18 are shown to be obtainable. The glider studied is shown to have acceptable longitudinal and directional stability characteristics through the

  14. A Scanning Jitter-Eliminating Keyboard Interface Based on MACH211SP and Verilog Programming%基于MACH211SP和Verilog编程的扫描消抖键盘接口电路设计

    Institute of Scientific and Technical Information of China (English)

    于云华; 石寅

    2003-01-01

    本文分析了传统键盘接口方法所存在的缺陷,提出了一种基于自动扫描消抖原理的硬件接口电路.选用fpGA器件MACH211SP进行了综合和适配.基于CadenceLDVNC-Verilog的时序仿真分析和实际样片电路的功能验证表明,该接口设计完全符合要求.

  15. Classifying Genomic Sequences by Sequence Feature Analysis

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hua Liu; Dian Jiao; Xiao Sun

    2005-01-01

    Traditional sequence analysis depends on sequence alignment. In this study, we analyzed various functional regions of the human genome based on sequence features, including word frequency, dinucleotide relative abundance, and base-base correlation. We analyzed the human chromosome 22 and classified the upstream,exon, intron, downstream, and intergenic regions by principal component analysis and discriminant analysis of these features. The results show that we could classify the functional regions of genome based on sequence feature and discriminant analysis.

  16. Influence of Mach number and static pressure on plasma flow control of supersonic and rarefied flows around a sharp flat plate

    Science.gov (United States)

    Coumar, Sandra; Lago, Viviana

    2017-06-01

    This paper presents an experimental investigation, carried out at the Icare Laboratory by the FAST team, focusing on plasma flow control in supersonic and rarefied regime. The study analyzes how the Mach number as well as the ambient pressure modify the repercussions of the plasma actuator on the shock wave. It follows previous experiments performed in the MARHy (ex-SR3) wind tunnel with a Mach 2 flow interacting with a sharp flat plate, where modifications induced by a plasma actuator were observed. The flat plate was equipped with a plasma actuator composed of two aluminum electrodes. The upstream one was biased with a negative DC potential and thus, created a glow discharge type plasma. Experimental measurements showed that the boundary layer thickness and the shock wave angle increased when the discharge was ignited. The current work was performed with two nozzles generating Mach 4 flows but at two different static pressures: 8 and 71 Pa. These nozzles were chosen to study independently the impact of the Mach number and the impact of the pressure on the flow behavior. In the range of the discharge current considered in this experimental work, it was observed that the shock wave angle increased with the discharge current of +15% for the Mach 2 flow but the increase rate doubled to +28% for the Mach 4 flow at the same static pressure, showing that the discharge effect is even more significant when boosting the flow speed. When studying the effect of the discharge on the Mach 4 flow at higher static pressure, it was observed that the topology of the plasma changed drastically and the increase in the shock wave angle with the discharge current of +21 %.

  17. Main: Sequences [KOME

    Lifescience Database Archive (English)

    Full Text Available Sequences Amino Acid Sequence Amino Acid sequence of full length cDNA (Longest ORF) kome_ine_full_seq...uence_amino_db.fasta.zip kome_ine_full_sequence_amino_db.zip kome_ine_full_sequence_amino_db ...

  18. Shotgun protein sequencing.

    Energy Technology Data Exchange (ETDEWEB)

    Faulon, Jean-Loup Michel; Heffelfinger, Grant S.

    2009-06-01

    A novel experimental and computational technique based on multiple enzymatic digestion of a protein or protein mixture that reconstructs protein sequences from sequences of overlapping peptides is described in this SAND report. This approach, analogous to shotgun sequencing of DNA, is to be used to sequence alternative spliced proteins, to identify post-translational modifications, and to sequence genetically engineered proteins.

  19. Nonlinear theory of nonstationary low Mach number channel flows of freely cooling nearly elastic granular gases.

    Science.gov (United States)

    Meerson, Baruch; Fouxon, Itzhak; Vilenkin, Arkady

    2008-02-01

    We employ hydrodynamic equations to investigate nonstationary channel flows of freely cooling dilute gases of hard and smooth spheres with nearly elastic particle collisions. This work focuses on the regime where the sound travel time through the channel is much shorter than the characteristic cooling time of the gas. As a result, the gas pressure rapidly becomes almost homogeneous, while the typical Mach number of the flow drops well below unity. Eliminating the acoustic modes and employing Lagrangian coordinates, we reduce the hydrodynamic equations to a single nonlinear and nonlocal equation of a reaction-diffusion type. This equation describes a broad class of channel flows and, in particular, can follow the development of the clustering instability from a weakly perturbed homogeneous cooling state to strongly nonlinear states. If the heat diffusion is neglected, the reduced equation becomes exactly soluble, and the solution develops a finite-time density blowup. The blowup has the same local features at singularity as those exhibited by the recently found family of exact solutions of the full set of ideal hydrodynamic equations [I. Fouxon, Phys. Rev. E 75, 050301(R) (2007); I. Fouxon,Phys. Fluids 19, 093303 (2007)]. The heat diffusion, however, always becomes important near the attempted singularity. It arrests the density blowup and brings about previously unknown inhomogeneous cooling states (ICSs) of the gas, where the pressure continues to decay with time, while the density profile becomes time-independent. The ICSs represent exact solutions of the full set of granular hydrodynamic equations. Both the density profile of an ICS and the characteristic relaxation time toward it are determined by a single dimensionless parameter L that describes the relative role of the inelastic energy loss and heat diffusion. At L>1 the intermediate cooling dynamics proceeds as a competition between "holes": low-density regions of the gas. This competition resembles Ostwald

  20. Measurement and Analysis of the Noise Radiated by Low Mach Number Centrifugal Blowers.

    Science.gov (United States)

    Yeager, David Marvin

    An investigation was performed of the broad band, aerodynamically generated noise in low tip-speed Mach number, centrifugal air moving devices. An interdisciplinary experimental approach was taken which involved investigation of the aerodynamic and acoustic fields, and their mutual relationship. The noise generation process was studied using two experimental vehicles: (1) a scale model of a homologous family of centrifugal blowers typical of those used to cool computer and business equipment, and (2) a single blade from a centrifugal blower impeller placed in a known, controllable flow field. The radiation characteristics of the model blower were investigated by measuring the acoustic intensity distribution near the blower inlet and comparing it with the intensity near the inlet to an axial flow fan. Results showed that the centrifugal blower is a distributed, random noise source, unlike an axial fan which exhibited the effects of a coherent, interacting source distribution. Aerodynamic studies of the flow field in the inlet and at the discharge to the rotating impeller were used to assess the mean flow distribution through the impeller blade channels and to identify regions of excessive turbulence near the rotating blade row. Both circumferential and spanwise mean flow nonuniformities were identified along with a region of increased turbulence just downstream of the scroll cutoff. The fluid incidence angle, normally taken as an indicator of blower performance, was estimated from mean flow data as deviating considerably from an ideal impeller design. An investigation of the noise radiated from the single, isolated airfoil was performed using modern correlation and spectral analysis techniques. Radiation from the single blade in flow was characterized using newly developed expressions for the correlation area and the dipole source strength per unit area, and from the relationship between the blade surface pressure and the incident turbulent flow field. Results