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Sample records for high-j intruder orbitals

  1. Deformation driving intruder orbitals in {sup 77}Kr

    Energy Technology Data Exchange (ETDEWEB)

    Sylvan, G.N.; Doering, J.; Johns, G.D.; Tabor, S.L. [Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States); Gross, C.J. [ORISE, Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831 (United States)]|[Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Baktash, C.; Jin, H.; Stracener, D.W. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Hua, P.F.; Korolija, M.; LaFosse, D.R.; Sarantites, D.G. [Chemistry Department, Washington University, St. Louis, Missouri 63130 (United States); Cristancho, F.; Landulfo, E.; Saladin, J.X. [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Cederwall, B.; Lee, I.Y.; Macchiavelli, A.O.; Rathbun, W. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Vander Molen, A. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)

    1997-08-01

    High-spin states in {sup 77}Kr were identified via analysis of prompt {gamma}-{gamma} coincidences in the {sup 58}Ni({sup 29}Si,2{alpha}2p) reaction at 128 MeV at the Gammasphere facility. Evaporation channel selection was achieved using the 95 element Microball charged-particle detector. 27 new states and 42 new transitions were found. The positive-parity bands were confirmed and the {alpha}={minus}(1)/(2) band extended to (39)/(2){sup +}. The negative-parity signature pair was extended to (31)/(2){sup {minus}} and (37)/(2){sup {minus}}. Two new high-lying negative-parity bands were found extending from a state of spin I=(15)/(2) and energy 2.6 MeV to 17.4 MeV at I=((55)/(2)). The new bands appear highly deformed and become yrast at high spin. A three-quasiparticle structure based on deformation driving, low-K unique-parity and intruder orbitals is suggested for them. {copyright} {ital 1997} {ital The American Physical Society}

  2. The impact of the intruder orbitals on the structure of neutron-rich Ag isotopes

    Directory of Open Access Journals (Sweden)

    Y.H. Kim

    2017-09-01

    Full Text Available The low-lying high-spin yrast band structure of neutron-rich 113,118–121Ag has been established for the first time using prompt γ-ray spectroscopy of isotopically identified fission fragments produced in the 9Be(238U, fγ fusion- and transfer-induced fission processes. The newly obtained level energies follow the systematics of the neighboring isotopes. The sequences of levels exhibit an energy inheritance from states in the corresponding Cd core. A striking constancy of a large signature splitting in odd-A Ag throughout the long chain of isotopes with 50orbital shell-model calculations including only two intruder orbitals πg9/2 and νh11/2 from two consecutive shells above Z=50 and N=82 for protons and neutrons respectively, resulting in the πg9/2−3×νh11/2m configurations. The newly established bands were understood as fairly pure, built mainly on unique-parity intruder configurations and coupled to the basic states of the Cd core.

  3. Lazy Mobile Intruders

    DEFF Research Database (Denmark)

    Mödersheim, Sebastian Alexander; Nielson, Flemming; Nielson, Hanne Riis

    We present a new technique for analyzing platforms that execute potentially malicious code, such as web-browsers, mobile phones, or virtualized infrastructures. Rather than analyzing given code, we ask what code an intruder could create to break a security goal of the platform. To avoid searching...... a small, abstract formalism that models the essence of mobile code. We provide a decision procedure for security against arbitrary intruder ambients when the honest ambients can only perform a bounded number of steps and without path constraints in communication....

  4. Intruder Activity Analysis under Unreliable Sensor Networks

    Energy Technology Data Exchange (ETDEWEB)

    Tae-Sic Yoo; Humberto E. Garcia

    2007-09-01

    This paper addresses the problem of counting intruder activities within a monitored domain by a sensor network. The deployed sensors are unreliable. We characterize imperfect sensors with misdetection and false-alarm probabilities. We model intruder activities with Markov Chains. A set of Hidden Markov Models (HMM) models the imperfect sensors and intruder activities to be monitored. A novel sequential change detection/isolation algorithm is developed to detect and isolate a change from an HMM representing no intruder activity to another HMM representing some intruder activities. Procedures for estimating the entry time and the trace of intruder activities are developed. A domain monitoring example is given to illustrate the presented concepts and computational procedures.

  5. Transformation around intruders in granular media

    Science.gov (United States)

    Jop, Pierre; Merceron, Aymeric; Sauret, Alban

    2017-06-01

    Sintering, glass melting and other industrially relevant processes turn batches of grains into homogeneous products. Such processes involve coupled chemical and physical transformations of the granular packing. For sake of simplicity, we study how local evolutions on grains (volume decreases for example) entail mechanical rearrangements in the overall pile. Inert bidisperse metallic disks are mixed and confined in a vertical 2D cell. At the bottom of this set-up, initial intruders (one or two) have been previously set and mechanically linked to a linear motorized jack. While we quasi-statically pull the intruder(s) downward out of the cell at constant speed and constant liberated surface, we tracked the surrounding granular packing. Events largely distributed both spatially and temporally occur around intruders. We focus on the influence of the distance between the intruders on the local dynamic of the packing. We compare the distribution of the size of the event and their frequency as function of the relative position of the intruder, as a function of their radius. We show that their influence decreases rapidly. At short distance the mechanical perturbation induced by one intruder can destabilize the packing around the other.

  6. Transformation around intruders in granular media

    Directory of Open Access Journals (Sweden)

    Jop Pierre

    2017-01-01

    Full Text Available Sintering, glass melting and other industrially relevant processes turn batches of grains into homogeneous products. Such processes involve coupled chemical and physical transformations of the granular packing. For sake of simplicity, we study how local evolutions on grains (volume decreases for example entail mechanical rearrangements in the overall pile. Inert bidisperse metallic disks are mixed and confined in a vertical 2D cell. At the bottom of this set-up, initial intruders (one or two have been previously set and mechanically linked to a linear motorized jack. While we quasi-statically pull the intruder(s downward out of the cell at constant speed and constant liberated surface, we tracked the surrounding granular packing. Events largely distributed both spatially and temporally occur around intruders. We focus on the influence of the distance between the intruders on the local dynamic of the packing. We compare the distribution of the size of the event and their frequency as function of the relative position of the intruder, as a function of their radius. We show that their influence decreases rapidly. At short distance the mechanical perturbation induced by one intruder can destabilize the packing around the other.

  7. Influence of i{sub 13/2} proton and j{sub 15/2} neutron intruding orbitals on the behaviour of 190 mass region superdeformed nuclei; Influence des orbitales intruses proton i{sub 13/2} et neutron j{sub 15/2} sur le comportement des noyaux superdeformes de la region de masse 190

    Energy Technology Data Exchange (ETDEWEB)

    Duprat, J.

    1995-01-01

    This work concerns the study of the nuclear superdeformation phenomenon in the A = 190 mass region. The superdeformed (SD) states in {sup 193}Tl, {sup 194}Tl {sup 195}Tl were produced via heavy-ion induced reactions and studied with the EUROGAM gamma multidetector array. The analysis of high-multiplicity events allowed the study of the magnetic properties of the SD states in these nuclei. For the first time, the g-factor of a proton orbital in a SD nucleus in the A = 190 mass region has been extracted. This measurement indicates that the two known bands in {sup 195}Tl-SD are built on the i{sub 13/2} proton intruder orbital. A new SD band has been found in this isotope: it is the first SD band built on an excited proton state found in the A = 190 region. Finally an interaction between two pairs of bands has been established in {sup 194}Tl; this interaction indicate the crossing of two neutron orbitals above the N = 112 gap. The magnetic properties of the states of the SD bands in {sup 194}Tl reveals that these bands are built on configurations in which the single proton and neutron intrinsic spins are aligned. Comparison between different SD bands in the Thallium isotopes shows the prominent role of the i{sub 13/2} proton and the j{sub 15/2} neutron intruder orbitals in the smooth increase of the dynamical moment of inertia as a function of the rotational frequency. In addition, this work reports on the first observation of a SD rotational band produced in a (HI, {alpha}xn) reaction channel. The study of the maximum spin reached by the SD bands indicates both a competition between alpha emission and fission of the compound nucleus, and the limitation due to the fission process in the population of the SD nuclei in the A = 190 region. (author). 120 refs., 112 figs., 22 tabs., 2 ann.

  8. Orbits

    CERN Document Server

    Xu, Guochang

    2008-01-01

    This is the first book of the satellite era which describes orbit theory with analytical solutions of the second order with respect to all possible disturbances. Based on such theory, the algorithms of orbits determination are completely revolutionized.

  9. Orbital

    OpenAIRE

    Yourshaw, Matthew Stephen

    2017-01-01

    Orbital is a virtual reality gaming experience designed to explore the use of traditional narrative structure to enhance immersion in virtual reality. The story structure of Orbital was developed based on the developmental steps of 'The Hero's Journey,' a narrative pattern identified by Joseph Campbell. Using this standard narrative pattern, Orbital is capable of immersing the player quickly and completely for the entirety of play time. MFA

  10. Orbital

    Science.gov (United States)

    Hanson, Robert M.

    2003-06-01

    ORBITAL requires the following software, which is available for free download from the Internet: Netscape Navigator, version 4.75 or higher, or Microsoft Internet Explorer, version 5.0 or higher; Chime Plug-in, version compatible with your OS and browser (available from MDL).

  11. Capturing intruders based on Voronoi diagrams assisted by information networks

    Directory of Open Access Journals (Sweden)

    Jonghoek Kim

    2017-01-01

    Full Text Available We consider a scenario of deploying multiple robots to capture all intruders in a cluttered workspace with many obstacles. Here, we say that a robot captures an intruder in the case where the intruder is within the maximum range of a weapon on the robot. All robots use the Voronoi diagram as the topological map of the workspace. Due to obstacles, intruders are confined to move along a passage between obstacles. Suppose the weapons on every robot are powerful enough to cover a passage in the workspace. Then, we can consider a simplified scenario such that robots and intruders are restricted to stay on the Voronoi diagram. We assume that a robot can detect the position of any intruder using the information network. This article presents an intruder capturing strategy that is robust to time delay in data transfer using the network. Our strategy does not require the localization of a node or a robot. Based on this strategy, we provide an upper bound for the minimum number of robots required to capture all intruders on a general graph, which leads to a result of the Voronoi diagram. Lastly, we provide MATLAB (version 7.10.0 R2010a simulations to verify the effectiveness of our capturing strategy.

  12. On the submerging of a spherical intruder into granular beds

    Science.gov (United States)

    Wu, Chuan-Yu; Zhang, Ling; Chen, Lan

    2017-06-01

    Granular materials are complex systems and their mechanical behaviours are determined by the material properties of individual particles, the interaction between particles and the surrounding media, which are still incompletely understood. Using an advanced discrete element method (DEM), we simulate the submerging process of a spherical projectile (an intruder) into granular materials of various properties with a zero penetration velocity (i.e. the intruder is touching the top surface of the granular bed and released from stationary) and examine its settling behaviour. By systematically changing the density and size of the intruder and the particle density (i.e. the density of the particles in the granular bed), we find that the intruder can sink deep into the granular bed even with a zero penetration velocity. Furthermore, we confirm that under certain conditions the granular bed can behave like a Newtonian liquid and the submerging intruder can reach a constant velocity, i.e. the terminal velocity, identical to the settling of a sphere in a liquid, as observed experimentally. A mathematical model is also developed to predict the maximum penetration depth of the intruder. The model predictions are compared with experimental data reported in the literature,good agreement was obtained, demonstrating the model can accurately predict the submerging behaviour of the intruder in the granular media.

  13. On the submerging of a spherical intruder into granular beds

    Directory of Open Access Journals (Sweden)

    Wu Chuan-Yu

    2017-01-01

    Full Text Available Granular materials are complex systems and their mechanical behaviours are determined by the material properties of individual particles, the interaction between particles and the surrounding media, which are still incompletely understood. Using an advanced discrete element method (DEM, we simulate the submerging process of a spherical projectile (an intruder into granular materials of various properties with a zero penetration velocity (i.e. the intruder is touching the top surface of the granular bed and released from stationary and examine its settling behaviour. By systematically changing the density and size of the intruder and the particle density (i.e. the density of the particles in the granular bed, we find that the intruder can sink deep into the granular bed even with a zero penetration velocity. Furthermore, we confirm that under certain conditions the granular bed can behave like a Newtonian liquid and the submerging intruder can reach a constant velocity, i.e. the terminal velocity, identical to the settling of a sphere in a liquid, as observed experimentally. A mathematical model is also developed to predict the maximum penetration depth of the intruder. The model predictions are compared with experimental data reported in the literature,good agreement was obtained, demonstrating the model can accurately predict the submerging behaviour of the intruder in the granular media.

  14. Intruder States and their Local Effect on Spectral Statistics

    CERN Document Server

    Flores, J; Leyvraz, F

    1997-01-01

    The effect on spectral statistics and on the revival probability of intruder states in a random background is analysed numerically and with perturbative methods. For random coupling the intruder does not affect the GOE spectral statistics of the background significantly, while a constant coupling causes very strong correlations at short range with a fourth power dependence of the spectral two-point function at the origin.The revival probability is significantly depressed for constant coupling as compared to random coupling.

  15. How sand grains stop a high speed intruder

    Science.gov (United States)

    Behringer, Robert

    When a speeding intruder impacts on a granular material, it comes rapidly to rest after penetrating only a modest distance. Empirical dynamical models, dating to the 19th century (if not earlier), describe the drag on the intruder in terms of two types of depth-dependent forces: one a static force, which also includes gravity, and the other a collisional force proportional to the square of the instantaneous speed of the intruder. What processes occur in the material to so quickly decelerate the intruder? We address this question through experiments and simulations (work of Lou Kondic and collaborators). We first probe the granular response using quasi-two-dimensional granular materials consisting of photoelastic discs. When such a particle experiences a force, it appears bright under cross-polarized illumination. High speed video reveals dynamic force transmission into the material along force chains that form in response to the intruder motion. These chains are nearly normal to the intruder surface, implying that collisional rather than frictional forces dominate the momentum transfer from intruder to grains. These observations allow the formation of a collision-based model that correctly captures the collisional drag force for both 2D and 3D intruders of a variety of shapes. This talk will develop a collisional picture of impact, and also explore the change in the system response as the impact speed increases. Experimental collaborators include Abe Clark, Cacey Stevens Bester, and Alec Petersen. This work supported by DTRA, NSF Grant DMR1206351, NASA Grant NNX15AD38G, and the William M. Keck Foundation.

  16. The Star Wars Kid and the Bedroom Intruder

    DEFF Research Database (Denmark)

    Christensen, Jørgen Riber

    2011-01-01

    Jørgen Riber Christensen's article Star Wars Kid and the Bedroom Intruder looks at how people may unexpectedly become icons of the Internet, through a transgression of the private sphere. Surveillance and celebrity is revealed to be bound together with a disciplinary effect, at the same time...

  17. Low Cost Night Vision System for Intruder Detection

    Science.gov (United States)

    Ng, Liang S.; Yusoff, Wan Azhar Wan; R, Dhinesh; Sak, J. S.

    2016-02-01

    The growth in production of Android devices has resulted in greater functionalities as well as lower costs. This has made previously more expensive systems such as night vision affordable for more businesses and end users. We designed and implemented robust and low cost night vision systems based on red-green-blue (RGB) colour histogram for a static camera as well as a camera on an unmanned aerial vehicle (UAV), using OpenCV library on Intel compatible notebook computers, running Ubuntu Linux operating system, with less than 8GB of RAM. They were tested against human intruders under low light conditions (indoor, outdoor, night time) and were shown to have successfully detected the intruders.

  18. Design and Implementation of an Embedded Smart Intruder Surveillance System

    Directory of Open Access Journals (Sweden)

    Sabri Naseer

    2018-01-01

    Full Text Available Remote and scattered valuable and sensitive locations such as labs and offices inside university campus need efficient monitoring and warning system. As well as scattered area and belonging. This research presents a Real-Time intruder Surveillance System based on a single board computer (SBC. Thus the design and development of a cost effective surveillance management system based SBC that can be deployed efficiently in remote and scattered locations such as universities belonging. The fusion of embedded Python codes with SBC that attached to cameras, Long distance sensors, alerting circuitry and wireless module presents a novel integration based effective cost solution and enhances SBC of much flexibility of improvement and development for pervasive remote locations. The system proves the high integrity of smooth working with web application, it’s cost effective and thus can be deployed as many of units to seize and concisely covered remote and scattered area as well as university belonging and departments. The system can be administrated by a remote user sparsely or geographically away from any networked workstation. The proposed solution offers efficient stand alone, flexibility to upgrade and cheap development and installation as well as cost effective ubiquitous surveillance solution. In conclusion, the system acceptable boundaries of successful intruder recognition and warning alert are computed between 1m and 3m distance of intruder from system camera. Recognition rate of 95% and 83% are achieved and the successful warning alert were in the range of 86-97%.

  19. Detection of Intelligent Intruders in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yun Wang

    2016-01-01

    Full Text Available Most of the existing research works on the intrusion detection problem in a wireless sensor network (WSN assume linear or random mobility patterns in abstracting intruders’ models in traversing the WSN field. However, in real-life WSN applications, an intruder is usually an intelligent mobile robot with environment learning and detection avoidance capability (i.e., the capability to avoid surrounding sensors. Due to this, the literature results based on the linear or random mobility models may not be applied to the real-life WSN design and deployment for efficient and effective intrusion detection in practice. This motivates us to investigate the impact of intruder’s intelligence on the intrusion detection problem in a WSN for various applications. To be specific, we propose two intrusion algorithms, the pinball and flood-fill algorithms, to mimic the intelligent motion and behaviors of a mobile intruder in detecting and circumventing nearby sensors for detection avoidance while heading for its destination. The two proposed algorithms are integrated into a WSN framework for intrusion detection analysis in various circumstances. Monte Carlo simulations are conducted, and the results indicate that: (1 the performance of a WSN drastically changes as a result of the intruder’s intelligence in avoiding sensor detections and intrusion algorithms; (2 network parameters, including node density, sensing range and communication range, play a crucial part in the effectiveness of the intruder’s intrusion algorithms; and (3 it is imperative to integrate intruder’s intelligence in the WSN research for intruder detection problems under various application circumstances.

  20. Coordinated group response to nest intruders in social shrimp.

    Science.gov (United States)

    Tóth, Eva; Duffy, J Emmett

    2005-03-22

    A key characteristic of highly social animals is collective group response to important stimuli such as invasion by enemies. The marine societies of social snapping shrimp share many convergences with terrestrial eusocial animals, including aggressive reaction to strangers, but no group actions have yet been observed in shrimp. Here we describe 'coordinated snapping', during which a sentinel shrimp reacts to danger by recruiting other colony members to snap in concert for several to tens of seconds. This distinctive behaviour is a specific response to intrusion by strange shrimp into the colony's sponge and is highly successful at repelling these intruders. Although coordinated snapping apparently functions analogously to alarm responses in other social animals, colony members in social shrimp do not rush to the site of the attack. Coordinated snapping appears instead to be a warning signal to would-be intruders that the sponge is occupied by a cooperative colony ready to defend it. This is the first evidence for coordinated communication in social shrimp and represents yet another remarkable convergence between social shrimp, insects and vertebrates.

  1. Fingerprint Liveness Detection in the Presence of Capable Intruders

    Directory of Open Access Journals (Sweden)

    Ana F. Sequeira

    2015-06-01

    Full Text Available Fingerprint liveness detection methods have been developed as an attempt to overcome the vulnerability of fingerprint biometric systems to spoofing attacks. Traditional approaches have been quite optimistic about the behavior of the intruder assuming the use of a previously known material. This assumption has led to the use of supervised techniques to estimate the performance of the methods, using both live and spoof samples to train the predictive models and evaluate each type of fake samples individually. Additionally, the background was often included in the sample representation, completely distorting the decision process. Therefore, we propose that an automatic segmentation step should be performed to isolate the fingerprint from the background and truly decide on the liveness of the fingerprint and not on the characteristics of the background. Also, we argue that one cannot aim to model the fake samples completely since the material used by the intruder is unknown beforehand. We approach the design by modeling the distribution of the live samples and predicting as fake the samples very unlikely according to that model. Our experiments compare the performance of the supervised approaches with the semi-supervised ones that rely solely on the live samples. The results obtained differ from the ones obtained by the more standard approaches which reinforces our conviction that the results in the literature are misleadingly estimating the true vulnerability of the biometric system.

  2. Localization Capability of Cooperative Anti-Intruder Radar Systems

    Directory of Open Access Journals (Sweden)

    Mauro Montanari

    2008-06-01

    Full Text Available System aspects of an anti-intruder multistatic radar based on impulse radio ultrawideband (UWB technology are addressed. The investigated system is composed of one transmitting node and at least three receiving nodes, positioned in the surveillance area with the aim of detecting and locating a human intruder (target that moves inside the area. Such systems, referred to also as UWB radar sensor networks, must satisfy severe power constraints worldwide imposed by, for example, the Federal Communications Commission (FCC and by the European Commission (EC power spectral density masks. A single transmitter-receiver pair (bistatic radar is considered at first. Given the available transmitted power and the capability of the receiving node to resolve the UWB pulses in the time domain, the surveillance area regions where the target is detectable, and those where it is not, are obtained. Moreover, the range estimation error for the transmitter-receiver pair is discussed. By employing this analysis, a multistatic system is then considered, composed of one transmitter and three or four cooperating receivers. For this multistatic system, the impact of the nodes location on area coverage, necessary transmitted power and localization uncertainty is studied, assuming a circular surveillance area. It is highlighted how area coverage and transmitted power, on one side, and localization uncertainty, on the other side, require opposite criteria of nodes placement. Consequently, the need for a system compromising between these factors is shown. Finally, a simple and effective criterion for placing the transmitter and the receivers is drawn.

  3. Vertical drag force acting on intruders of different shapes in granular media

    Science.gov (United States)

    Zaidi, Ali Abbas; Müller, Christoph

    2017-06-01

    The penetration of large objects into granular media is encountered commonly both in nature (e.g. impacts of meteors and projectiles) and engineering applications (e.g. insertion of tractor blades into sand). The motion of the impacting intruder in granular media is resisted by a granular drag force. In this work, we assess the effect of intruder shape on the granular drag force using discrete element modelling (DEM). The following intruder shapes were modelled: spherical, conical, cylindrical and cubical. We observed that the drag force can be described well by a power-law relationship with intrusion depth, independent of the intruder shape. However, the exponent of the power-law expression increases with increasing "flatness" of the intruder's impacting surface due to an increasing fraction of the granular media affected by the impact of the intruder.

  4. Intelligent Machine Vision for Automated Fence Intruder Detection Using Self-organizing Map

    Directory of Open Access Journals (Sweden)

    Veldin A. Talorete Jr.

    2017-03-01

    Full Text Available This paper presents an intelligent machine vision for automated fence intruder detection. A series of still captured images that contain fence events using Internet Protocol cameras was used as input data to the system. Two classifiers were used; the first is to classify human posture and the second one will classify intruder location. The system classifiers were implemented using Self-Organizing Map after the implementation of several image segmentation processes. The human posture classifier is in charge of classifying the detected subject’s posture patterns from subject’s silhouette. Moreover, the Intruder Localization Classifier is in charge of classifying the detected pattern’s location classifier will estimate the location of the intruder with respect to the fence using geometric feature from images as inputs. The system is capable of activating the alarm, display the actual image and depict the location of the intruder when an intruder is detected. In detecting intruder posture, the system’s success rate of 88%. Overall system accuracy for day-time intruder localization is 83% and an accuracy of 88% for night-time intruder localization

  5. Energy-efficient area coverage for intruder detection in sensor networks

    CERN Document Server

    He, Shibo; Li, Junkun

    2014-01-01

    This Springer Brief presents recent research results on area coverage for intruder detection from an energy-efficient perspective. These results cover a variety of topics, including environmental surveillance and security monitoring. The authors also provide the background and range of applications for area coverage and elaborate on system models such as the formal definition of area coverage and sensing models. Several chapters focus on energy-efficient intruder detection and intruder trapping under the well-known binary sensing model, along with intruder trapping under the probabilistic sens

  6. Close encounters of the third-body kind. [intruding bodies in binary star systems

    Science.gov (United States)

    Davies, M. B.; Benz, W.; Hills, J. G.

    1994-01-01

    We simulated encounters involving binaries of two eccentricities: e = 0 (i.e., circular binaries) and e = 0.5. In both cases the binary contained a point mass of 1.4 solar masses (i.e., a neutron star) and a 0.8 solar masses main-sequence star modeled as a polytrope. The semimajor axes of both binaries were set to 60 solar radii (0.28 AU). We considered intruders of three masses: 1.4 solar masses (a neutron star), 0.8 solar masses (a main-sequence star or a higher mass white dwarf), and 0.64 solar masses (a more typical mass white dwarf). Our strategy was to perform a large number (40,000) of encounters using a three-body code, then to rerun a small number of cases with a three-dimensional smoothed particle hydrodynamics (SPH) code to determine the importance of hydrodynamical effects. Using the results of the three-body runs, we computed the exchange across sections, sigma(sub ex). From the results of the SPH runs, we computed the cross sections for clean exchange, denoted by sigma(sub cx); the formation of a triple system, denoted by sigma(sub trp); and the formation of a merged binary with an object formed from the merger of two of the stars left in orbit around the third star, denoted by sigma(sub mb). For encounters between either binary and a 1.4 solar masses neutron star, sigma(sub cx) approx. 0.7 sigma(sub ex) and sigma(sub mb) + sigma(sub trp) approx. 0.3 sigma(sub ex). For encounters between either binary and the 0.8 solar masses main-sequence star, sigma(sub cx) approx. 0.50 sigma(sub ex) and sigma(sub mb) + sigma(sub trp) approx. 1.0 sigma(sub ex). If the main sequence star is replaced by a main-sequence star of the same mass, we have sigma(sub cx) approx. 0.5 sigma(sub ex) and sigma(sub mb) + sigma(sub trp) approx. 1.6 sigma(sub ex). Although the exchange cross section is a sensitive function of intruder mass, we see that the cross section to produce merged binaries is roughly independent of intruder mass. The merged binaries produced have semi

  7. Neuroendocrine and behavioral response to social confrontation: residents versus intruders, active versus passive coping styles.

    Science.gov (United States)

    Ebner, Karl; Wotjak, Carsten T; Landgraf, Rainer; Engelmann, Mario

    2005-01-01

    We investigated in the present study the neuroendocrine correlates in intruder and resident rats of a social confrontation. Adult male Wistar rats (intruders) were introduced into the home cage of a well-trained resident to induce characteristic agonistic interactions including physical attacks prior to separation by a wire mesh. The hypothalamic-pituitary-adrenal (HPA) axis activity and the intrahypothalamic release of arginine vasopressin (AVP) were monitored via chronically implanted jugular venous catheters and microdialysis probes aimed at the hypothalamic paraventricular nucleus (PVN), respectively. Based on the behavioral data collected during the 30-min confrontation, intruders and residents were additionally classified into two different subgroups: intruders which showed almost no freezing behavior (active copers) versus those showing pronounced freezing behavior (passive copers) and residents which were either predominantly aggressive or non-aggressive. The neuroendocrine data show that social confrontation caused a significantly increased secretion of the adrenocorticotropic hormone (ACTH) into plasma in both intruder subgroups, independently of their coping strategy. In contrast, plasma ACTH in residents was increased in response to social confrontation in non-aggressive animals only, whereas aggressive residents failed to mount an ACTH response. Interestingly, plasma AVP decreased in response to social confrontation in active intruders. As measured in microdialysates, the two groups of residents and passive intruders failed to show significant changes of intra-PVN release of AVP. In contrast, an increased release of this neuropeptide within the PVN could be monitored for active intruders. The data of the present study suggest that the different interpretation of an aversive encounter results in differences in the neuroendocrine response and intrahypothalamic vasopressinergic signaling in intruders versus residents.

  8. Exploring racial politics, personal history and critical reception: Clarence Brown's Intruder in the dust (1949)

    National Research Council Canada - National Science Library

    Young, Gwenda

    2013-01-01

    Discusses the complexities of director Clarence Brown's 1949 film "Intruder in the dust" concerning racial issues, the personal and social elements that contributed to its inception, and its reception...

  9. Inadvertent Intruder Analysis For The Portsmouth On-Site Waste Disposal Facility (OSWDF)

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Frank G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Phifer, Mark A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2014-01-22

    The inadvertent intruder analysis considers the radiological impacts to hypothetical persons who are assumed to inadvertently intrude on the Portsmouth OSWDF site after institutional control ceases 100 years after site closure. For the purposes of this analysis, we assume that the waste disposal in the OSWDF occurs at time zero, the site is under institutional control for the next 100 years, and inadvertent intrusion can occur over the following 1,000 year time period. Disposal of low-level radioactive waste in the OSWDF must meet a requirement to assess impacts on such individuals, and demonstrate that the effective dose equivalent to an intruder would not likely exceed 100 mrem per year for scenarios involving continuous exposure (i.e. chronic) or 500 mrem for scenarios involving a single acute exposure. The focus in development of exposure scenarios for inadvertent intruders was on selecting reasonable events that may occur, giving consideration to regional customs and construction practices. An important assumption in all scenarios is that an intruder has no prior knowledge of the existence of a waste disposal facility at the site. Results of the analysis show that a hypothetical inadvertent intruder at the OSWDF who, in the worst case scenario, resides on the site and consumes vegetables from a garden established on the site using contaminated soil (chronic agriculture scenario) would receive a maximum chronic dose of approximately 7.0 mrem/yr during the 1000 year period of assessment. This dose falls well below the DOE chronic dose limit of 100 mrem/yr. Results of the analysis also showed that a hypothetical inadvertent intruder at the OSWDF who, in the worst case scenario, excavates a basement in the soil that reaches the waste (acute basement construction scenario) would receive a maximum acute dose of approximately 0.25 mrem/yr during the 1000 year period of assessment. This dose falls well below the DOE acute dose limit of 500 mrem/yr. Disposal inventory

  10. Intelligent Security IT System for Detecting Intruders Based on Received Signal Strength Indicators

    Directory of Open Access Journals (Sweden)

    Yunsick Sung

    2016-10-01

    Full Text Available Given that entropy-based IT technology has been applied in homes, office buildings and elsewhere for IT security systems, diverse kinds of intelligent services are currently provided. In particular, IT security systems have become more robust and varied. However, access control systems still depend on tags held by building entrants. Since tags can be obtained by intruders, an approach to counter the disadvantages of tags is required. For example, it is possible to track the movement of tags in intelligent buildings in order to detect intruders. Therefore, each tag owner can be judged by analyzing the movements of their tags. This paper proposes a security approach based on the received signal strength indicators (RSSIs of beacon-based tags to detect intruders. The normal RSSI patterns of moving entrants are obtained and analyzed. Intruders can be detected when abnormal RSSIs are measured in comparison to normal RSSI patterns. In the experiments, one normal and one abnormal scenario are defined for collecting the RSSIs of a Bluetooth-based beacon in order to validate the proposed method. When the RSSIs of both scenarios are compared to pre-collected RSSIs, the RSSIs of the abnormal scenario are about 61% more different compared to the RSSIs of the normal scenario. Therefore, intruders in buildings can be detected by considering RSSI differences.

  11. Cooperative dynamics in the penetration of a group of intruders in a granular medium.

    Science.gov (United States)

    Pacheco-Vázquez, F; Ruiz-Suárez, J C

    2010-11-23

    An object moving in a fluid experiences a drag force that depends on its velocity, shape and the properties of the medium. From this simplest case to the motion of a flock of birds or a school of fish, the drag forces and the hydrodynamic interactions determine the full dynamics of the system. Similar drag forces appear when a single projectile impacts and moves through a granular medium, and this case is well studied in the literature. On the other hand, the case in which a group of intruders impact a granular material has never been considered. Here, we study the simultaneous penetration of several intruders in a very low-density granular medium. We find that the intruders move through it in a collective way, following a cooperative dynamics, whose complexity resembles flocking phenomena in living systems or the movement of reptiles in sand, wherein changes in drag are exploited to efficiently move or propel.

  12. Study of the high-j states in {sup 249}Cm.

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I.

    1998-07-16

    The authors have performed the reaction {sup 248}Cm({sup 4}He, {sup 3}He) using 98.5-MeV alpha particles from the IUCF cyclotron to populate high-j states in {sup 249}Cm. A tentative assignment of the K{sub 17/2} component of the 1/2{sup +}[880] Nilsson state has been made.

  13. A study of the management of 55 traumatically intruded permanent incisor teeth in children.

    LENUS (Irish Health Repository)

    Stewart, C

    2009-01-01

    These were to examine the main presenting, treatment and outcome factors for intruded permanent incisors in children, the effect of apical development and degree of intrusion on decisions on repositioning, the effect of apical development status on the maintenance of pulp vitality and the time of pulp extirpation and to compare the decisions made to the advice given in existing clinical guidelines.

  14. Automated electronic intruder simulator for evaluation of odd frequency microwave detectors

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    A microwave intruder simulator for testing motion detection sensors is described. This simulator can be used to evaluate a variety of microwave sensors regardless of the value of the center frequency of the signal utilized. Representative curves from the evaluation of one microwave sensor are also presented.

  15. Psychophysiological and Behavioral Responses to a Novel Intruder Threat Task for Children on the Autism Spectrum

    Science.gov (United States)

    South, Mikle; Taylor, Katherine M.; Newton, Tiffani; Christensen, Megan; Jamison, Nathan K.; Chamberlain, Paul; Johnston, Oliver; Crowley, Michael J.; Higley, J. Dee

    2017-01-01

    We measured skin conductance response (SCR) to escalating levels of a direct social threat from a novel, ecologically-relevant experimental paradigm, the Intruder Threat Task. We simultaneously evaluated the contribution of social symptom severity and behavioral movement. Children with AS group showed less psychophysiological reactivity to social…

  16. Rotational band structure of intruder configurations -- Success and limitations of the cranked shell model

    Energy Technology Data Exchange (ETDEWEB)

    Wyss, R. [Joint Inst. for Heavy-Ion Research, Oak Ridge, TN (United States). Holifield Heavy Ion Research Facility

    1993-12-31

    Rotational bands built on intruder configurations are discussed within the Cranked Shell Model. The experimental observed alignment pattern occurring in these bands cannot be accounted for by standard mean field calculations. The discrepancy between theory and experiment is traced back to the fact that the neutron-proton interaction is only partly and indirectly included in the standard mean field approach.

  17. Lift on side by side intruders of various geometries within a granular flow

    Science.gov (United States)

    Acevedo-Escalante, M. F.; Caballero-Robledo, G. A.

    2017-06-01

    Obstacles within fluids have been widely used in engineering and in physics to study hydrodynamic interactions. In granular matter, objects within a granular flow have helped to understand fundamental features of drag and lift forces. In our group, we have studied numerically the flow mediated interaction between two static disks within a vertical granular flow in a two-dimensional container where the flow velocity and the distance between obstacles were varied. Attractive and repulsive forces were found depending on flow velocity and separation between intruders. The simulations evidenced a relationship between the average flow velocity in a specific section ahead of the obstacles and the attractive-repulsive lift. On the other hand, it was showed that the lift force on an object dragged within a granular medium depends on the shape of the intruder. Here we present experimental results of the interaction between two side-by-side intruders of different shapes within a vertical granular flow. We built a quasi-two-dimensional container in which we placed the intruders and using load cells we measured lift and drag forces during the discharge process for different flow velocities.

  18. The diagnostic value of lateral extraoral radiography for intruded maxillary primary incisors.

    Science.gov (United States)

    Holan, Gideon; Ram, Diana; Fuks, Anna B

    2002-01-01

    The purpose of the study was to assess the contribution of a lateral extraoral radiograph for diagnosing the relation between the root of intruded maxillary primary incisors and their permanent successors. Three pediatric dentists examined intruded primary teeth 0-7 days after injury. The relations between the primary and permanent teeth were assessed in three separate steps: 1) evaluation of clinical signs only; 2) evaluation of a periapical radiograph (no lateral radiograph); 3) evaluation of a lateral extraoral radiograph. The clinical and radiographic signs used to assess the relations were recorded. The lateral extraoral radiograph was regarded as contributory to diagnosis if the assessment after the third step differed significantly from that made after the first and second steps. Ninety-three evaluations of 53 intruded teeth in 37 children were available for analysis. The lateral extraoral radiograph was found valuable for assessment of the primary incisor's root alignment in only 5% (5/93) of the evaluations in which neither the clinical examination nor the periapical radiograph were contributory. Four of these five cases were in children less than 20 months old. In all other cases, the lateral radiograph was not contributory for two main reasons: It could not be evaluated due to overlap of multiple intruded teeth and/or when the teeth intruded were lateral incisors, and when the clinical and periapical radiographs were sufficient for diagnosis. Lateral extraoral radiographs should not be used routinely in cases of intrusion of primary incisors. The operator should base his or her diagnosis on clinical findings and examination of a periapical radiograph. The lateral extraoral radiograph should be taken only when its expected contribution to diagnosis can be confirmed, as in cases of children younger than 20 months.

  19. Intruder Polarization.

    Science.gov (United States)

    1985-12-01

    field coneonenti in the ground-frane in ter-s of j- P... cvcan ’Se ochieved. That result is given in (;.!J-a, b, c) of Ref. !.Tt is re,)eato𔃻 Selo ,: in...steps would leed to tern~s wit’, increasinrjr hipher or ’er veriation with and the ratio 4i). The latter r-tio approaches unity ~ ~ ( a )Ib’)race as

  20. A PSDPF interaction to describe the 1 h{omega} intruder states in sd shell nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bouhelal, M., E-mail: m_bouhelal@yahoo.fr [Laboratoire de Physique Appliquee et Theorique, Universite de Tebessa, Tebessa (Algeria); Haas, F.; Caurier, E.; Nowacki, F. [IPHC, CNRS/IN2P3, Universite de Strasbourg, Strasbourg (France); Bouldjedri, A. [Departement de Physique, Faculte des Sciences, Universite de Batna, Batna (Algeria)

    2011-08-01

    In the level schemes of sd shell nuclei, there is generally at relatively low excitation energies, coexistence of normal 0 h{omega} positive parity states and of intruder 1 h{omega} negative parity states. The aim of the present work is to describe these intruder states in the full p-sd-pf model space with a {sup 4}He core allowing one nucleon jump between the major shells. To construct our PSDPF interaction, we first modified the p-sd and sd-pf cross-monopole terms and then applied a fitting procedure to adjust all PSDPF parameters by comparing an extended set of experimental and calculated excitation energies. Results obtained with the new interaction have been finally compared with experimental data for nuclei throughout the sd shell.

  1. Aggression and dominance in cichlids in resident-intruder tests: the role of environmental enrichment

    Directory of Open Access Journals (Sweden)

    Vincent Nijman

    Full Text Available When establishing dominance residents have a greater likelihood to dominate intruders than vice versa, partially because the resident has more to loose that the intruder has to win. This is known as the prior residency effect. In environmentally rich environments this effect should be stronger than in poor environments. Recently Kadry & Barreto (2010, Neotrop Ichthyol 8: 329-332 tested this in the pearl cichlid Geophagus brasiliensis (17 test pairs and reported that environmental enrichment led to a reduction of aggression. We here present data on four other cichlids (332 test pairs showing a stronger prior residency effect in enriched conditions, and, for two species, an increase in aggression. We discuss possible reasons for the differences between studies, focussing on the relationship between aggression and dominance and sample size effects.

  2. Investigations on the internal shape of Constructal cavities intruding a heat generating body

    OpenAIRE

    Pouzesh Abouzar; Mohammad Reza Hajmohammadi; Poozesh Sadegh

    2015-01-01

    This paper deals with the influence that the internal shape of open ‘cavities’ exerts on the Constructal design of a heat generating body. Several shapes of cavity are studied; triangular, elliptical, trapezoidal and Y-shaped cavities intruding into a trapezoidal shaped solid with uniform heat generation. The trapezoidal solid is commonly used in round electronic devices. The geometric aspect ratios of the cavities and the solid are free to vary while the t...

  3. Optical fiber strain sensor for application in intelligent intruder detection systems

    Science.gov (United States)

    Stańczyk, Tomasz; Tenderenda, Tadeusz; Szostkiewicz, Lukasz; Bienkowska, Beata; Kunicki, Daniel; Murawski, Michal; Mergo, Pawel; Nasilowski, Tomasz

    2017-10-01

    Nowadays technology allows to create highly effective Intruder Detection Systems (IDS), that are able to detect the presence of an intruder within a defined area. In such systems the best performance can be achieved by combining different detection techniques in one system. One group of devices that can be applied in an IDS, are devices based on Fiber Optic Sensors (FOS). The FOS benefits from numerous advantages of optical fibers like: small size, light weight or high sensitivity. In this work we present a novel Microstructured Optical Fiber (MOF) characterized by increased strain sensitivity dedicated to distributed acoustic sensing for intelligent intruder detection systems. By designing the MOF with large air holes in close proximity to a fiber core, we increased the effective refractive index sensitivity to longitudinal strain. The presented fiber can be easily integrated in a floor system in order to detect any movement in the investigated area. We believe that sensors, based on the presented MOF, due to its numerous advantages, can find application in intelligent IDS.

  4. Fusion of image data for beyond-the-fence intruder detection and assessment.

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Cynthia Lee

    2007-09-01

    The use of combined imagery from different imaging sensors has the potential to provide significant performance improvements over the use of a single image sensor for beyond-the-fence detection and assessment of intruders. Sensing beyond the fence is very challenging for imagers due to uncertain dynamic and harsh environmental conditions. The use of imagery from varying spectral bands can alleviate some of this difficulty by providing stronger truth data that can be combined with truth data from other spectral bands to increase detection capabilities. Imagery fusion of collocated, aligned sensors covering varying spectral bands [1,2,3] has already been shown to improve the probability of detection and the reduction of nuisance alarms. The development of new multi-spectral sensing algorithms that incorporate sensors that are not collocated will enable automated sensor-based detection, assessment, localization, and tracking in harsh dynamic environments. This level of image fusion will provide the capability of creating spatial information about the intruders. In turn, the fidelity of sensed activities is increased resulting in opportunities for greater system intelligence for inferring and interpreting these activities and formulating automated responses. The goal of this work is to develop algorithms that will enable the fusion of multi-spectral data for improved detection of intruders and the creation of spatial information that can be further used in assessment decisions.

  5. Applying fluctuation theorem on position fluctuations of an intruder penetrating a 2D wet granular medium near jamming state

    Science.gov (United States)

    Bonachita, Mike A.; Confesor, Mark Nolan P.

    2017-08-01

    We monitor the position of an intruder penetrating a two-dimensional mono-disperse granular assembly near the jamming state. We employ the Fluctuation Theorem (FT) to characterize the fluctuation in the intruder position. The FT takes the form: log [Π (+Δ xτ)/Π (-Δ xτ)]=FτΔ xτ where Δxτ is the displacement of the intruder after a time interval τ, Π(Δxτ) is the probability distribution of Δxτ, and Fτ is a functional. Our results showed that FT was obeyed for all the intruder driving speeds used in our study and that Fτ converges to F at long time scale. Furthermore, a linear dependence of F with the driving speed was measured in agreement to previous experiments.

  6. Digital design of functional surgery for odontogenic cyst intruding into maxillary sinus.

    Science.gov (United States)

    Hu, Ying Kai; Yang, Chi; Xu, Guang Zhou; Xie, Qian Yang

    2017-03-19

    Traditional Caldwell-Luc approach needs modifications for odontogenic cysts intruding into the maxillary sinus, to preserve sinus mucosa and bony contour. Recently, digital technology has been widely applied to the field of maxillofacial surgery, guiding the surgical plan and improving its accuracy. This study attempted to present and evaluate the functional surgery of odontogenic cysts intruding into the maxillary sinus using a computer-assisted pre-surgical design. Consecutive patients with odontogenic cysts intruding into the posterior part of the maxillary sinus were enrolled. Method I "Bony wall reimplantation method" was performed for large lesions exceeding the zygomatic alveolar crest but without apparent bone destruction of the anterior wall of the sinus, while Method II "bone removal method" was more convenient for small lesions near to the zygomatic alveolar crest. The gap was filled with a pedicled Buccal Fat Pad (BFP) after lesion removal and all cases were without inferior meatal antrostomy. A total of 45 cases were included in the study. 22 were operated using method I while 23 were operated with method II. Operations were completed in 20min. Pain disappeared in 3.62 days on average, and swelling 6.47 days. Nasal bleeding occurred in 8 patients lasting 1-3 days. Suppurative inflammation was observed in 1 patient, and infection occurred after bone reposition. Other repositioned free bony wall was without resorption in CT images. Sinus mucosa and bony wall should be conserved. Preoperative digital design can guide osteotomy effectively during the surgery. Bone reposition is not suitable for suppurative inflammation. The pedicled BFP is enough for drainage and inferior meatal antrostomy is not necessary. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  7. Long-term clinical and radiographic follow up of subluxated and intruded maxillary primary anterior teeth.

    Science.gov (United States)

    Qassem, Aya; Martins, Nathália da Motta; da Costa, Vanessa Polina Pereira; Torriani, Dione Dias; Pappen, Fernanda Geraldo

    2015-02-01

    This study aimed to determine the kinds of sequelae resulting from intrusive luxation and subluxative injuries in primary anterior teeth as well as the timing of such sequelae. In this longitudinal retrospective study, data were collected from dental records and radiographs of patients with traumatic dental injury (TDI) treated at the Centre for the Study and Treatment of Dental Trauma in Primary Dentition (Pelotas, RS, Brazil). Fifty-two children, with seventy intruded teeth, and 76 children, with 99 subluxated teeth, met the inclusion criteria. Sequelae, such as crown discoloration, fistula, pulp canal obliteration (PCO), inflammatory root resorption (IRR), and internal root resorption, were investigated. The data on the sequelae were distributed into eight follow-up periods: 0-30 days, 31-90 days, 91-180 days, 181-365 days, 1-2 years, 2-3 years, 3-4 years, and >4 years. The sample comprised 99 subluxation cases and 70 intruded teeth. Crown discoloration was the most prevalent sequelae. Among the subluxated teeth, discoloration, and PCO occurred within 180 days after TDI; however, the sequelae were also diagnosed after longer periods. Majority of sequelae of intrusion were diagnosed within the 181-365 days and 1-2 years periods but were also observed after more than 4 years of follow up. For both intrusion and subluxation, trauma sequelae were diagnosed even after the 3-4 years of follow-up. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Machine learning approach to detect intruders in database based on hexplet data structure

    Directory of Open Access Journals (Sweden)

    Saad M. Darwish

    2016-09-01

    Full Text Available Most of valuable information resources for any organization are stored in the database; it is a serious subject to protect this information against intruders. However, conventional security mechanisms are not designed to detect anomalous actions of database users. An intrusion detection system (IDS, delivers an extra layer of security that cannot be guaranteed by built-in security tools, is the ideal solution to defend databases from intruders. This paper suggests an anomaly detection approach that summarizes the raw transactional SQL queries into a compact data structure called hexplet, which can model normal database access behavior (abstract the user's profile and recognize impostors specifically tailored for role-based access control (RBAC database system. This hexplet lets us to preserve the correlation among SQL statements in the same transaction by exploiting the information in the transaction-log entry with the aim to improve detection accuracy specially those inside the organization and behave strange behavior. The model utilizes naive Bayes classifier (NBC as the simplest supervised learning technique for creating profiles and evaluating the legitimacy of a transaction. Experimental results show the performance of the proposed model in the term of detection rate.

  9. High-J CO survey of low-mass protostars observed with Herschel-HIFI

    Science.gov (United States)

    Yıldız, U. A.; Kristensen, L. E.; van Dishoeck, E. F.; San José-García, I.; Karska, A.; Harsono, D.; Tafalla, M.; Fuente, A.; Visser, R.; Jørgensen, J. K.; Hogerheijde, M. R.

    2013-08-01

    Context. In the deeply embedded stage of star formation, protostars start to heat and disperse their surrounding cloud cores. The evolution of these sources has traditionally been traced through dust continuum spectral energy distributions (SEDs), but the use of CO excitation as an evolutionary probe has not yet been explored due to the lack of high-J CO observations. Aims: The aim is to constrain the physical characteristics (excitation, kinematics, column density) of the warm gas in low-mass protostellar envelopes using spectrally resolved Herschel data of CO and compare those with the colder gas traced by lower excitation lines. Methods: Herschel-HIFI observations of high-J lines of 12CO, 13CO, and C18O (up to Ju = 10, Eu up to 300 K) are presented toward 26 deeply embedded low-mass Class 0 and Class I young stellar objects, obtained as part of the Water In Star-forming regions with Herschel (WISH) key program. This is the first large spectrally resolved high-J CO survey conducted for these types of sources. Complementary lower J CO maps were observed using ground-based telescopes, such as the JCMT and APEX and convolved to matching beam sizes. Results: The 12CO 10-9 line is detected for all objects and can generally be decomposed into a narrow and a broad component owing to the quiescent envelope and entrained outflow material, respectively. The 12CO excitation temperature increases with velocity from ~60 K up to ~130 K. The median excitation temperatures for 12CO, 13CO, and C18O derived from single-temperature fits to the Ju = 2-10 integrated intensities are ~70 K, 48 K and 37 K, respectively, with no significant difference between Class 0 and Class I sources and no trend with Menv or Lbol. Thus, in contrast to the continuum SEDs, the spectral line energy distributions (SLEDs) do not show any evolution during the embedded stage. In contrast, the integrated line intensities of all CO isotopologs show a clear decrease with evolutionary stage as the envelope is

  10. [Orbital cellulitis].

    Science.gov (United States)

    Mouriaux, F; Rysanek, B; Babin, E; Cattoir, V

    2012-01-01

    Orbital cellulitis is uncommon in ophthalmologic practice. The majority of cases arise from direct spread of sinus infection or eyelid infection. Clinically, orbital cellulitis is divided into two forms: the preseptal form, anterior to the orbital septum, and the retroseptal form, posterior to the orbital septum. Management and prognosis differ widely between the two types. The retroseptal form or "true" orbital cellulitis is a severe disease with potentially disastrous consequences for vision and survival. Clinical examination and urgent CT scanning are indispensable for correct diagnosis, evaluation of severity, surgical planning and antibiotic selection. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  11. Consolidation of a WSN and Minimax Method to Rapidly Neutralise Intruders in Strategic Installations

    Directory of Open Access Journals (Sweden)

    Angela Ribeiro

    2012-03-01

    Full Text Available Due to the sensitive international situation caused by still-recent terrorist attacks, there is a common need to protect the safety of large spaces such as government buildings, airports and power stations. To address this problem, developments in several research fields, such as video and cognitive audio, decision support systems, human interface, computer architecture, communications networks and communications security, should be integrated with the goal of achieving advanced security systems capable of checking all of the specified requirements and spanning the gap that presently exists in the current market. This paper describes the implementation of a decision system for crisis management in infrastructural building security. Specifically, it describes the implementation of a decision system in the management of building intrusions. The positions of the unidentified persons are reported with the help of a Wireless Sensor Network (WSN. The goal is to achieve an intelligent system capable of making the best decision in real time in order to quickly neutralise one or more intruders who threaten strategic installations. It is assumed that the intruders’ behaviour is inferred through sequences of sensors’ activations and their fusion. This article presents a general approach to selecting the optimum operation from the available neutralisation strategies based on a Minimax algorithm. The distances among different scenario elements will be used to measure the risk of the scene, so a path planning technique will be integrated in order to attain a good performance. Different actions to be executed over the elements of the scene such as moving a guard, blocking a door or turning on an alarm will be used to neutralise the crisis. This set of actions executed to stop the crisis is known as the neutralisation strategy. Finally, the system has been tested in simulations of real situations, and the results have been evaluated according to the final

  12. Sleep paralysis and "the bedroom intruder": the role of the right superior parietal, phantom pain and body image projection.

    Science.gov (United States)

    Jalal, Baland; Ramachandran, Vilayanur S

    2014-12-01

    Sleep paralysis (SP) is a common condition occurring either at sleep onset or sleep offset. During SP the sleeper experiences gross motor paralysis while the sensory system is clear. Hypnogogic and hypnopompic hallucinations are common during SP and may involve seeing, hearing, and sensing the presence of menacing intruders in one's bedroom. This "intruder" is often perceived as a shadowy humanoid figure. Supernatural accounts of this hallucinated intruder are common across cultures. In this paper, we postulate that a functional disturbance of the right parietal cortex explains the shadowy nocturnal bedroom intruder hallucination during SP. This hallucination may arise due to a disturbance in the multisensory processing of body and self at the temporoparietal junction. We specifically propose that this perceived intruder is the result of a hallucinated projection of the genetically "hard-wired" body image (homunculus), in the right parietal region; namely, the same circuits that dictate aesthetic and sexual preference of body morphology. One way to test this hypothesis would be to study clinical populations who may have genetically acquired "irregularities" in their internal hard-wired body image in the right superior parietal lobule (SPL); for example, individuals with apotemnophilia or anorexia nervosa. If such individuals experience SP (e.g., induced in a sleep lab), and they hallucinate this shadowy figure, one would predict that they would see humanoid shadows and shapes with body irregularities, mirroring their own internal body image morphology. If correct, our hypothesis will offer a neurological explanation for this nocturnal bedroom intruder that has been a source of controversy, and striking and implausible cultural interpretations throughout history. Indeed, if our proposed hypothesis is tested and corroborated, dissemination of such findings would provide great relief to SP experiencers worldwide and could potentially be used in a therapeutic context

  13. Endodontic and Orthodontic Management of Traumatically Intruded Teeth with Horizontal Root Fracture: A Case Report

    Directory of Open Access Journals (Sweden)

    Marcos Jacobovitz

    2011-01-01

    Full Text Available This report describes the case of an 8-year-old boy that was referred to endodontic and orthodontic treatment after suffering an injury that led to intrusion of the maxillary right permanent central incisor, palatal displacement of the upper right lateral incisor, and root fracture of both central incisors. Both injured teeth were immature and had open apices. The intruded tooth was repositioned by endodontic and orthodontic management. Endodontic therapy was performed in both teeth with periodical changes of calcium-hydroxide-based paste as root canal dressing and introduction of MTA as an apical barrier. The postoperative course was uneventful with clinical and radiographic success up to 3 and 1/2 years of follow up. In the present case, orthodontic repositioning combined with endodontic therapy constitued a viable alternative treatment for intrusive luxations in immature permanent teeth.

  14. Investigations on the internal shape of Constructal cavities intruding a heat generating body

    Directory of Open Access Journals (Sweden)

    Pouzesh Abouzar

    2015-01-01

    Full Text Available This paper deals with the influence that the internal shape of open ‘cavities’ exerts on the Constructal design of a heat generating body. Several shapes of cavity are studied; triangular, elliptical, trapezoidal and Y-shaped cavities intruding into a trapezoidal shaped solid with uniform heat generation. The trapezoidal solid is commonly used in round electronic devices. The geometric aspect ratios of the cavities and the solid are free to vary while the total volume occupied by the solid and the cavity are fixed. The objective is minimizing the peak (hot spot temperature with respect to the geometrical parameters of the system. Finite element method is employed to calculate the peak temperature of the solid. With respect to the Constructal thermal design, the numerical results prove that, utilizing the triangular and Y-Shaped cavities can result more reliable and effective rather than other studied cavities.

  15. Energy of the 2p1h intruder state in $^{34}$Al

    CERN Multimedia

    The second 0$^{+}$ state in $^{34}$Si, of high importance for the understanding of the island of inversion at N=20, has been recently observed through the $\\beta$- decay of a predicted long-lived low-lying isomeric 1$^{+}$ state in $^{34}$Al. We intend to measure the unknown excitation energy of this isomer using the ISOLTRAP Penning-trap mass spectrometer. Since a recent experiment at ISOLDE (IS-530) showed that the full $\\beta$- strength in the decay of $^{34}$Mg goes through this 1$^{+}$ state in $^{34}$Al, we propose to perform a direct mass measurement of the daughter $^{34}$Al ions trapped after the decay of $^{34}$Mg. Mass measurements indicate that the 4$^{−}$ ground state in $^{34}$Al may be an excited state, the ground state being therefore the intruder 1$^{+}$ state. In another run, we propose to perform a remeasurement of the mass of the 4$^{−}$ ground state.

  16. Modeling and Validation of a Navy A6-Intruder Actively Controlled Landing Gear System

    Science.gov (United States)

    Horta, Lucas G.; Daugherty, Robert H.; Martinson, Veloria J.

    1999-01-01

    Concepts for long-range air travel are characterized by airframe designs with long, slender, relatively flexible fuselages. One aspect often overlooked is ground-induced vibration of these aircraft. This paper presents an analytical and experimental study of reducing ground-induced aircraft vibration loads by using actively controlled landing gear. A facility has been developed to test various active landing gear control concepts and their performance, The facility uses a Navy A6 Intruder landing gear fitted with an auxiliary hydraulic supply electronically controlled by servo valves. An analytical model of the gear is presented, including modifications to actuate the gear externally, and test data are used to validate the model. The control design is described and closed-loop test and analysis comparisons are presented.

  17. Aggression and dominance in cichlids in resident-intruder tests: the role of environmental enrichment

    Directory of Open Access Journals (Sweden)

    Vincent Nijman

    2011-01-01

    Full Text Available When establishing dominance residents have a greater likelihood to dominate intruders than vice versa, partially because the resident has more to loose that the intruder has to win. This is known as the prior residency effect. In environmentally rich environments this effect should be stronger than in poor environments. Recently Kadry & Barreto (2010, Neotrop Ichthyol 8: 329-332 tested this in the pearl cichlid Geophagus brasiliensis (17 test pairs and reported that environmental enrichment led to a reduction of aggression. We here present data on four other cichlids (332 test pairs showing a stronger prior residency effect in enriched conditions, and, for two species, an increase in aggression. We discuss possible reasons for the differences between studies, focussing on the relationship between aggression and dominance and sample size effects.No estabelecimento de dominancia, residentes têm uma maior probabilidade de dominar os intrusos que vice-versa, em parte porque o residente tem mais a perder que o invasor tem a ganhar. Isto é conhecido como o efeito de residência prévia. Em ambientes ecologicamente ricos esse efeito deve ser mais forte do que em ambientes pobres. Recentemente Kadry & Barreto (2010, Neotrop. Ichthyol. 8: 329-332 testaram isso no cará Geophagus brasiliensis (17 pares de teste e relataram que o enriquecimento ambiental levou a uma redução de agressão. Aqui apresentamos dados de quatro outros ciclídeos (332 pares de teste, mostrando um efeito mais forte de residência prévia em condições enriquecidas, e, para duas espécies, o aumento da agressão. Discutimos possíveis razões para as diferenças entre os estudos, concentrando-nos sobre a relação entre agressão e dominação e os efeitos do tamanho da amostra.

  18. ORBITAL, CELLULITIS

    African Journals Online (AJOL)

    Aim: The purpose of this study was to assess the prevalence of paranasal sinusitis as a cause of orbital cellulitis and to identify the commonest sinus(es) involved in our setting. Methods: A retrospective review of the case notes of 47 patients with orbital cellulitis admitted into the ophthalmic ward of the University College ...

  19. Orbital velocity

    OpenAIRE

    Modestino, Giuseppina

    2016-01-01

    The trajectory and the orbital velocity are determined for an object moving in a gravitational system, in terms of fundamental and independent variables. In particular, considering a path on equipotential line, the elliptical orbit is naturally traced, verifying evidently the keplerian laws. The case of the planets of the solar system is presented.

  20. Territorial responses of male blue tits to simulated dynamic intrusions: effects of song overlap and intruder location

    DEFF Research Database (Denmark)

    Poesel, Angelika; Dabelsteen, Torben

    2005-01-01

    song alternating. A territory owner should therefore perceive an intruder overlapping its songs and staying inside its territory as a greater threat than one alternating and exiting the territory quickly. To test this hypothesis we used playback to interact with territorial male blue tits, Parus...

  1. The Hot Orbit: Orbital Cellulitis

    Science.gov (United States)

    Chaudhry, Imtiaz A.; Al-Rashed, Waleed; Arat, Yonca O.

    2012-01-01

    Orbital cellulitis is an uncommon condition previously associated with severe complications. If untreated, orbital cellulitis can be potentially sight and life threatening. It can affect both adults and children but has a greater tendency to occur in the pediatric age group. The infection most commonly originates from sinuses, eyelids or face, retained foreign bodies, or distant soources by hematogenous spread. It is characterized by eyelid edema, erythema, chemosis, proptosis, blurred vision, fever, headache, and double vision. A history of upper respiratory tract infection prior to the onset is very common especially in children. In the era prior to antibiotics, vision loss from orbital cellulitis was a dreaded complication. Currently, imaging studies for detection of orbital abcess, the use of antibiotics and early drainage have mitigated visual morbidity significantly. The purpose of this review is to describe current investigative strategies and management options in the treatment of orbital cellulitis, establish their effectiveness and possible complications due to late intervention. PMID:22346113

  2. Foreign body orbital cyst

    DEFF Research Database (Denmark)

    Yazdanfard, Younes; Heegard, Steffen; Fledelius, Hans C.

    2001-01-01

    Ophthalmology, penetrating orbital injury, orbital foreign body, ultrasound, computed tomography (CT), histology......Ophthalmology, penetrating orbital injury, orbital foreign body, ultrasound, computed tomography (CT), histology...

  3. City dweller responses to multiple stressors intruding into their homes: noise, light, odour, and vibration.

    Science.gov (United States)

    Pedersen, Eja

    2015-03-18

    Urban densification increases exposure to noise, light, odour, and vibration in urban dwellings. Exposure from combined environmental stressors intruding into the home could increase the risk of adverse effects on wellbeing, even when the exposure is at a relatively low level. This study assesses the prevalence of annoyance with a combination of potential environmental stressors common in urban areas and the association with wellbeing. A questionnaire was sent by mail to residents in five areas in Halmstad (Sweden) with similar socioeconomic and housing characteristics but different exposure (response rate 56%; n=385). Of the respondents, 50% were annoyed to some degree by at least one of the suggested stressors, most commonly by noise and vibration from local traffic. Structural equation modelling showed that annoyance led to lowered quality of life via the mediating construct residential satisfaction, which in turn was influenced by place attachment and perceived restoration possibilities in the dwelling. Stress had a negative impact on quality of life, but was not directly correlated to annoyance. Stress was however correlated with sensitivity. The findings suggest that dose-response relationships for environmental stressors should be studied in a broader context of environmental and individual factors. Also relatively low levels of exposure should be mitigated, especially if several stressors are present.

  4. Mixed convection flow of nanofluid in a square enclosure with an intruded rectangular fin

    Energy Technology Data Exchange (ETDEWEB)

    Cong, Ran; Zhou, Xuanyu; De Souza Machado, Bruno; Das, Prodip K., E-mail: prodip.das@ncl.ac.uk [School of Mechanical and Systems Engineering Newcastle University Newcastle upon Tyne, NE1 7RU United Kingdom (United Kingdom)

    2016-07-12

    Mixed convection flow in enclosures has been a subject of interest for many years due to their ever increasing applications in solar collectors, electronic cooling, lubrication technologies, food processing, and nuclear reactors. In comparison, little effort has been given to the problem of mixed convection in enclosures filled with nanofluids, while the addition of nanoparticles in a fluid base to alter specific material properties is considered a feasible solution for many heat transfer problems. Mixed convection of nanofluids is a challenging problem as the addition of nanoparticles changes the fluid’s thermo-physical properties as well as due to the complex interactions among inertia, viscous, and buoyancy forces. In this study, a two-dimensional steady-state numerical model has been developed to investigate mixed convection flow of nanofluids in a square enclosure with an intruded rectangular fin and to optimize the fin geometry for maximizing the heat transfer using the Constructal design. The model has been developed using ANSYS-FLUENT for various fin geometries. Flow fields, temperature fields, and heat transfer rates are examined for different values of Rayleigh and Reynolds numbers for several geometries of the fin with the aim of maximizing the heat transfer from the fin to the surrounding flow. Outcome of this study provides important insight into the heat transfer behavior of nanofluids, which will help in developing novel geometries with enhanced and controlled heat transfer for solar collectors and electronic devices.

  5. Shape coexistence and shell-model intruder states in the lead region studied by $\\alpha$ -decay

    CERN Multimedia

    2002-01-01

    % IS336 \\\\ \\\\ Low-lying 0$^+$ states in even-even nuclei near closed shells can be a manifestation of the coexistence of different shapes in the same nucleus. Deformed bandstructures built upon these 0$^+$ states, coexisting at low energy with the ground state band, have been observed in several regions of the nuclear chart, including the Z=82 region. Such structures have been found in the neutron-deficient even Pb nuclei and the mixing between intruder and normal states has been studied by the $\\alpha$- decay of $^{194, 196, 198}$Po towards the 0$^+$ excited and ground states in $^{190, 192, 194}$Pb using $\\alpha$-e-t coincidence events. It is expected that shape coexistence will occur in the light Po isotopes as well. Evidence for a deformed band at low excitation energy in $^{196, 198}$Po has been found in in-beam studies and the $\\alpha$-decay of $^{202}$Rn studied at ISOLDE revealed feeding to a 0$^+$~state at 816~keV in $^{198}$Po. \\\\ \\\\It is our intention to investigate the $^{194, 196}$Po nuclei with ...

  6. Management of traumatically intruded permanent maxillary lateral incisor - Case report and review of literature

    Directory of Open Access Journals (Sweden)

    Deepak Sharma

    2016-01-01

    Full Text Available Primary etiologic factors of trauma in the permanent dentition are bicycle accidents, sports accidents, falls, and fights. From the standpoint of therapy, anatomy, and prognosis, five different types of luxation lesions are recognized: Concussion, subluxation, extrusive luxation, lateral luxation, and intrusive luxation. Intrusive luxation is apical displacement of tooth into the alveolar bone. The tooth is driven into the socket, compressing the periodontal ligament, and commonly causes a crushing fracture of the alveolar socket. It is considered one of the most severe luxation injuries to affect permanent teeth. Intrusion injuries are often associated with severe damage to the tooth, periodontium, and pulpal tissue. The rare occurrence of this injury, 0.3–1.9% in the permanent dentition, has resulted in limited studies to support suggested treatment regimens. Clinical treatment for intrusion is especially difficult because of the severe complications accompanying it. These complications include pulp necrosis or obliteration, inflammatory root resorption, ankylosis, replacement root resorption, and loss of marginal bone support. Hence, the aim of presenting this case report of intrusive luxation is to highlight the importance of prompt care and root canal dressing and discuss the several treatments proposed to reposition the intruded teeth.

  7. First Evidence of Shape Coexistence in the ^{78}Ni Region: Intruder 0_{2}^{+} State in ^{80}Ge.

    Science.gov (United States)

    Gottardo, A; Verney, D; Delafosse, C; Ibrahim, F; Roussière, B; Sotty, C; Roccia, S; Andreoiu, C; Costache, C; Delattre, M-C; Deloncle, I; Etilé, A; Franchoo, S; Gaulard, C; Guillot, J; Lebois, M; MacCormick, M; Marginean, N; Marginean, R; Matea, I; Mihai, C; Mitu, I; Olivier, L; Portail, C; Qi, L; Stan, L; Testov, D; Wilson, J; Yordanov, D T

    2016-05-06

    The N=48 ^{80}Ge nucleus is studied by means of β-delayed electron-conversion spectroscopy at ALTO. The radioactive ^{80}Ga beam is produced through the isotope separation on line photofission technique and collected on a movable tape for the measurement of γ and e^{-} emission following β decay. An electric monopole E0 transition, which points to a 639(1) keV intruder 0_{2}^{+} state, is observed for the first time. This new state is lower than the 2_{1}^{+} level in ^{80}Ge, and provides evidence of shape coexistence close to one of the most neutron-rich doubly magic nuclei discovered so far, ^{78}Ni. This result is compared with theoretical estimates, helping to explain the role of monopole and quadrupole forces in the weakening of the N=50 gap at Z=32. The evolution of intruder 0_{2}^{+} states towards ^{78}Ni is discussed.

  8. Effect of Jobelyn® on intruder- and isolation-induced aggressive behavior in mice.

    Science.gov (United States)

    Umukoro, Solomon; Omogbiya, Itivere Adrian; Eduviere, Taghogho Anthony

    2013-01-01

    Aggression is a violent behavior emitted against another organism that may lead to its harm or death and thus is of public health significance, which necessitates the search for agents with anti-aggressive property. This study investigated the effect of Jobelyn® (JB), a unique African polyherbal formulation, on intruder- and isolation-induced aggressive behaviors in mice. Male mice that showed aggression after being housed individually with female counterparts for 3 weeks or kept in isolation for 4 weeks were treated orally (p.o.) with JB (5, 10 or 50 mg/kg), haloperidol (HP) (1 mg/kg), fluoxetine (FL) (10 mg/kg), p-chlorophenylalanine (PCPA) (20 mg/kg), mianserin (MS) (50 mg/kg) or distilled water (10 mL/kg) 60 min before being tested for aggression. Interaction studies involving oral administration of PCPA (20 mg/kg), FL (10 mg/kg) or MS (50 mg/kg) to aggressive mice that had received JB (5 or 10 mg/kg, p.o.) 30 min earlier were assessed. The effect of JB (5, 10 or 50 mg/kg, p.o.) on defensive behaviors was also evaluated. JB (5, 10 or 50 mg/kg) decreased aggressive behaviors without impairing the defensive mechanisms of mice. PCPA (20 mg/kg), an inhibitor of 5-hydroxytryptamine (5-HT) biosynthesis, increased aggressive responses and reduced the anti-aggressive effect of JB. FL (10 mg/kg), a 5-HT reuptake inhibitor, significantly suppressed aggression but did not alter the effect of JB on aggression. MS (50 mg/kg), a 5-HT receptor antagonist, reduced aggression and enhanced the effect of JB on aggression. These findings suggest that JB has anti-aggressive activity, which may be related to the enhancement of serotonergic system.

  9. Measuring virgin female aggression in the female intruder test (FIT: effects of oxytocin, estrous cycle, and anxiety.

    Directory of Open Access Journals (Sweden)

    Trynke R de Jong

    Full Text Available The costs of violence and aggression in our society have stimulated the scientific search for the predictors and causes of aggression. The majority of studies have focused on males, which are considered to be more aggressive than females in most species. However, rates of offensive behavior in girls and young women are considerable and are currently rising in Western society. The extrapolation of scientific results from males to young, non-maternal females is a priori limited, based on the profound sex differences in brain areas and functioning of neurotransmitters involved in aggression. Therefore, we established a paradigm to assess aggressive behavior in young virgin female rats, i.e. the female intruder test (FIT. We found that approximately 40% of un-manipulated adult (10-11 weeks old female Wistar rats attack an intruder female during the FIT, independent of their estrous phase or that of their intruder. In addition, adolescent (7-8 weeks old female rats selected for high anxiety behavior (HABs displayed significantly more aggression than non-selected (NAB or low-anxiety (LAB rats. Intracerebroventricular infusion of oxytocin (OXT, 0.1 µg/5 µl inhibited aggressive behavior in adult NAB and LAB, but not HAB females. Adolescent NAB rats that had been aggressive towards their intruder showed increased pERK immunoreactivity (IR in the hypothalamic attack area and reduced pERK-IR in OXT neurons in the paraventricular hypothalamic nucleus compared to non-aggressive NAB rats. Taken together, aggressive behavior in young virgin female rats is partly dependent on trait anxiety, and appears to be under considerable OXT control.

  10. Discovery of a new isomeric state in $^{68}$Ni: Evidence for a highly-deformed proton intruder state

    CERN Document Server

    Dijon, A; De France, G; De Angelis, G; Duchêne, G; Dudouet, J; Franchoo, S; Gadea, A; Gottardo, A; Hüyük, T; Jacquot, B; Kusoglu, A; Lebhertz, D; Lehaut, G; Martini, M; Napoli, D R; Nowacki, F; Péru, S; Poves, A; Recchia, F; Redon, N; Sahin, E; Schmitt, C; Sferrazza, M; Sieja, K; Stezowski, O; Valiente-Dobon, J J; Vancraeyenest, A; Zheng, Y

    2012-01-01

    We report on the observation of a new isomeric state in $^{68}$Ni. We suggest that the newly observed state at 168(1) keV above the first 2$^+$ state is a $\\pi(2p-2h)$ 0$^{+}$ state across the major Z=28 shell gap. Comparison with theoretical calculations indicates a pure proton intruder configuration and the deduced low-lying structure of this key nucleus suggests a possible shape coexistence scenario involving a highly deformed state.

  11. Effect of Vertical Rate Error on Recovery from Loss of Well Clear Between UAS and Non-Cooperative Intruders

    Science.gov (United States)

    Cone, Andrew; Thipphavong, David; Lee, Seung Man; Santiago, Confesor

    2016-01-01

    When an Unmanned Aircraft System (UAS) encounters an intruder and is unable to maintain required temporal and spatial separation between the two vehicles, it is referred to as a loss of well-clear. In this state, the UAS must make its best attempt to regain separation while maximizing the minimum separation between itself and the intruder. When encountering a non-cooperative intruder (an aircraft operating under visual flight rules without ADS-B or an active transponder) the UAS must rely on the radar system to provide the intruders location, velocity, and heading information. As many UAS have limited climb and descent performance, vertical position andor vertical rate errors make it difficult to determine whether an intruder will pass above or below them. To account for that, there is a proposal by RTCA Special Committee 228 to prohibit guidance systems from providing vertical guidance to regain well-clear to UAS in an encounter with a non-cooperative intruder unless their radar system has vertical position error below 175 feet (95) and vertical velocity errors below 200 fpm (95). Two sets of fast-time parametric studies was conducted, each with 54000 pairwise encounters between a UAS and non-cooperative intruder to determine the suitability of offering vertical guidance to regain well clear to a UAS in the presence of radar sensor noise. The UAS was not allowed to maneuver until it received well-clear recovery guidance. The maximum severity of the loss of well-clear was logged and used as the primary indicator of the separation achieved by the UAS. One set of 54000 encounters allowed the UAS to maneuver either vertically or horizontally, while the second permitted horizontal maneuvers, only. Comparing the two data sets allowed researchers to see the effect of allowing vertical guidance to a UAS for a particular encounter and vertical rate error. Study results show there is a small reduction in the average severity of a loss of well-clear when vertical maneuvers

  12. Inflammation of the Orbit

    Science.gov (United States)

    ... Glaucoma (Video) Macular Degeneration Additional Content Medical News Inflammation of the Orbit (Inflammatory Orbital Pseudotumor) By James ... Introduction to Eye Socket Disorders Cavernous Sinus Thrombosis Inflammation of the Orbit Orbital Cellulitis Preseptal Cellulitis Tumors ...

  13. Neuropeptide S reduces mouse aggressiveness in the resident/intruder test through selective activation of the neuropeptide S receptor.

    Science.gov (United States)

    Ruzza, Chiara; Asth, Laila; Guerrini, Remo; Trapella, Claudio; Gavioli, Elaine C

    2015-10-01

    Neuropeptide S (NPS) regulates various biological functions by selectively activating the NPS receptor (NPSR). In particular NPS evokes robust anxiolytic-like effects in rodents together with a stimulant and arousal promoting action. The aim of the study was to investigate the effects of NPS on the aggressiveness of mice subjected to the resident/intruder test. Moreover the putative role played by the endogenous NPS/NPSR system in regulating mice aggressiveness was investigating using mice lacking the NPSR receptor (NPSR(-/-)) and the NPSR selective antagonists [(t)Bu-D-Gly(5)]NPS and SHA 68. NPS (0.01-1 nmol, icv) reduced, in a dose dependent manner, both the time that resident mice spent attacking the intruder mice and their number of attacks, producing pharmacological effects similar to those elicited by the standard anti-aggressive drug valproate (300 mg/kg, ip). This NPS effect was evident in NPSR wild type (NPSR(+/+)) mice but completely disappeared in NPSR(-/-) mice. Moreover, NPSR(-/-) mice displayed a significantly higher time spent attacking than NPSR(+/+) mice. [(t)Bu-D-Gly(5)]NPS (10 nmol, icv) did not change the behavior of mice in the resident/intruder test but completely counteracted NPS effects. SHA 68 (50 mg/kg, ip) was inactive per se and against NPS. In conclusion, this study demonstrated that NPS produces anti-aggressive effects in mice through the selective activation of NPSR and that the endogenous NPS/NPSR system can exert a role in the control of aggressiveness levels under the present experimental conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Indirect usage of miniscrew anchorage to intrude overerupted mandibular incisors in a Class II patient with a deep overbite.

    Science.gov (United States)

    Ishihara, Yoshihito; Kuroda, Shingo; Sugawara, Yasuyo; Balam, Tarek A; Takano-Yamamoto, Teruko; Yamashiro, Takashi

    2013-04-01

    Vertical dentoalveolar discrepancies are a common problem in orthodontic patients but are often difficult to treat with traditional mechanics. This case report illustrates the successful treatment of overerupted mandibular incisors via the indirect use of miniscrew anchorage. A woman (age, 22 years 9 months) had chief complaints of maxillary incisor protrusion and crooked teeth. An excessive curve of Spee caused by elongation of the mandibular incisors was also found. The patient was diagnosed with a severe Class II Division 1 malocclusion and a deep overbite. After extraction of the mandibular first premolars and the subsequent leveling phase, the elongated incisors were intruded with a novel method, which involved the combined use of sectional archwires and miniscrews placed in the premolar areas. After the procedure, the mandibular incisors had been intruded by 6.5 mm with no undesirable side effects. The total active treatment period was 42 months. The resultant occlusion and satisfactory facial profile were maintained after 30 months of retention. Our novel intrusion approach shows potential for correcting a deep overbite. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  15. Pair Identity and Smooth Variation Rules Applicable for the Spectroscopic Parameters of H2O Transitions Involving High-J States

    Science.gov (United States)

    Ma, Q.; Tipping, R. H.; Lavrentieva, N. N.

    2010-01-01

    Two basic rules (i.e. the pair identity and the smooth variation) applicable for H2O transitions involving high-J states have been discovered. The origins of these rules are the properties of the energy levels and wavefunctions of H2O states with the quantum number J above certain boundaries. As a result, for lines involving high-J states in individually defined groups, all their spectroscopic parameters (i.e. the transition wavenumber, intensity, pressure-broadened half-width, pressure-induced shift, and temperature exponent) must follow these rules. One can use these rules to screen spectroscopic data provided by databases and to identify possible errors. In addition, by using extrapolation methods within the individual groups, one is able to predict the spectroscopic parameters for lines in this group involving very high-J states. The latter are required in developing high-temperature molecular spectroscopic databases such as HITEMP.

  16. High-J CO lines from low- to high-mass YSOs: the dynamics of protostellar envelopes

    Science.gov (United States)

    San José-García, Irene; Mottram, Joseph C.; van Dishoeck, Ewine F.; Kristensen, Lars E.; Yildiz, Umut A.

    2013-07-01

    In order to form a complete understanding of Star Formation, it is critical to determine the similarities and differences between low- and high-mass young stellar objects (YSOs) from both a physical and chemical perspective. Within this context, the "Water in Star forming regions with Herschel" key program (WISH; van Dishoeck et al. 2011) is investigating the different processes that characterise protostellar environments across a wide range of luminosities by observing water, CO and other important molecules. The study of the CO and isotopologue emission lines of 51 YSOs has shown a strong linear correlation between the line and bolometric luminosities for all observed lines, suggesting that high J CO transitions (J >= 5) can be used as tracers of dense gas. In addition, the majority of the 12CO line profiles can be decomposed into broad and narrow Gaussian components, while the C18O spectra show a single velocity component. Analysis of the C18O data has also motivated a more detailed study of the dynamics of protostellar envelopes. In these regions, non-thermal motions, such as turbulence and infall, dominate this line profile but in different amounts for low (J < 5) and high rotational transitions. The width of the C18O lines becomes broader at higher J for low-mass protostars but remains constant for more massive YSOs. For the first time a characterisation of the dynamics in the inner warmer regions of protostellar envelopes can be performed and compared to the colder outer parts as a function of source luminosity. This is achieved through comparison with 1-dimensional spherically symmetric radiative transfer models. This study will allow us to better understand where infall and turbulence are dominant within protostellar envelopes and how this varies with luminosity.

  17. Preseptal Cellulitis, Orbital Cellulitis, Orbital Abscess

    Directory of Open Access Journals (Sweden)

    Rana Altan Yaycıoğlu

    2012-12-01

    Full Text Available Patients with orbital infections present to our clinic usually with unilateral pain, hyperemia, and edema of the eyelids. The differentiation between preseptal and orbital cellulitis is utmost important in that the second requires hospitalization. Since in orbital cellulitis, the tissues posterior to the orbital septum are involved, signs such as conjunctival chemosis, limited eye movement, decreased vision, as well as afferent pupil defect secondary to optic nerve involvement may also be observed. Prompt intravenous antibiotic treatment should be started, and surgical drainage may be performed if patient shows failure to improve in 48 hours despite optimal management. Without treatment, the clinical course may progress to subperiosteal or orbital abscess, and even to cavernous sinus thrombosis. (Turk J Ophthalmol 2012; 42: Supplement 52-6

  18. Transneptunian Orbit Computation

    Science.gov (United States)

    Virtanen, J.; Tancredi, G.; Bernstein, G. M.; Spahr, T.; Muinonen, K.

    We review the orbit computation problem for the transneptunian population. For these distant objects, the problem is characterized by their short observed orbital arcs, which are known to be coupled with large uncertainties in orbital elements. Currently, the observations of even the best observed objects, such as the first-ever transneptunian object (TNO), Pluto, cover only a fraction of their revolution. Furthermore, of the some 1200 objects discovered since 1992, roughly half have observations from only one opposition. To ensure realistic analyses of the population, e.g., in the derivation of unbiased orbital distributions or correlations between orbital and physical properties, realistic estimation of orbital uncertainties is important. We describe the inverse problem of orbit computation, emphasizing the short-arc problem and its statistical treatment. The complete solution to the problem can be given in terms of the orbital-element probability density function (p.d.f.), which then serves as a starting point for any further analysis, where knowledge of orbital uncertainties is required. We give an overview of the variety of computational techniques developed for TNO orbital uncertainty estimation in the recent years. After presenting the current orbital distribution, we demonstrate their application to several prediction problems, such as classification, ephemeris prediction, and dynamical analysis of objects. We conclude with some future prospects for TNO orbit computation concerning the forthcoming next-generation surveys, including the anticipated evolution of TNO orbital uncertainties over the coming decades.

  19. ASC Champ Orbit Model

    DEFF Research Database (Denmark)

    Riis, Troels; Jørgensen, John Leif

    1999-01-01

    This documents describes a test of the implementation of the ASC orbit model for the Champ satellite.......This documents describes a test of the implementation of the ASC orbit model for the Champ satellite....

  20. Lunar Orbiter Photo Gallery

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Orbiter Photo Gallery is an extensive collection of over 2,600 high- and moderate-resolution photographs produced by all five of the Lunar Orbiter...

  1. Introducing Earth's Orbital Eccentricity

    Science.gov (United States)

    Oostra, Benjamin

    2015-01-01

    Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is…

  2. Idiopathic granulomatous orbital inflammation

    NARCIS (Netherlands)

    Mombaerts, I.; Schlingemann, R. O.; Goldschmeding, R.; Koornneef, L.

    1996-01-01

    PURPOSE: Granulomatous orbital inflammation may occur as an isolated condition of unknown origin. These idiopathic granulomatous lesions are believed to belong to the orbital pseudotumor group by some authors, whereas others consider them sarcoidosis limited to the orbit. The aim of this study is to

  3. Can I intrude?

    Science.gov (United States)

    Kalha, Anmol

    2007-01-01

    Studies were identified using Medline, PubMed, Medline In-Process and Other Non-Indexed Citations, all evidence-based medicine reviews (Cochrane Database of Systematic Reviews, ACP (American College of Physicians) Journal Club, Database of Reviews of Effectiveness (DARE) and CCTR (Cochrane Controlled Trials Register), Embase, Web of Science and LILACS(Latin American and Caribbean Health Sciences). Studies included were clinical trials in humans where the intrusion of permanent incisors was determined using cephalometric radiograph superimpositions. A qualitative synthesis of all included studies was conducted, along with a fixed-effects meta-analysis of two studies that employed the same treatment method. Of 28 articles meeting the initial selection criteria, only four were included because of methodological issues with the others. Two studies that used the segmented arch technique were included in a fixed-effects meta-analysis to evaluate the amount of incisor intrusion. The combined mean estimates were 1.46 mm (95% confidence interval, 1.05-1.86) for the maxillary incisor and 1.90 mm (95% confidence interval, 1.22-2.57) of intrusion for the mandibular incisor. True incisor intrusion is achievable in both arches, but the clinical significance of the magnitude of true intrusion as the sole treatment option is questionable for patients with severe deep bite. In non-growing patients, the segmented arch technique can produce 1.5 mm of incisor intrusion in the maxillary arch and 1.9 mm in the mandibular arch.

  4. Aids : A Rampant Intruder

    Directory of Open Access Journals (Sweden)

    Suresh Chandra

    2004-12-01

    Full Text Available The HIV/AIDS epidemic represents the most serious public health problem in India. There is no denial of the enormity of the problem. The prevalence of infection in all parts of the world highlights the spread from urban to rural areas and from high risk to general population. It is esti­mated that as on end of year 2004, 39.4 million people were infected with the virus. Migration of labour, low lit­eracy levels leading to low awareness, gender disparities, prevalence of sexually transmitted diseases and reproduc­tive tract infections are some of the factors attributed to the spread of HIV/AIDS.4.9 million ( 4.3 million - 6.4 million people have aquired HIV infection only in one year of span - 2004. The global AIDS epidemic killed 3.1 million ( 2,8 million- 3.5 million people in the past year.

  5. Lazy Mobile Intruders

    DEFF Research Database (Denmark)

    Mödersheim, Sebastian Alexander; Nielson, Flemming; Nielson, Hanne Riis

    2013-01-01

    that by communication, the malicious code can learn new information that it can use in subsequent operations, or that we may have several pieces of malicious code that can exchange information if they “meet”. To formalize both the platform and the malicious code we use the mobile ambient calculus, since it provides...

  6. Magnetotelluric evidence for massive sulphide mineralization in intruded sediments of the outer Vøring Basin, mid-Norway

    Science.gov (United States)

    Corseri, Romain; Senger, Kim; Selway, Kate; Abdelmalak, Mohamed Mansour; Planke, Sverre; Jerram, Dougal A.

    2017-06-01

    A highly conductive body (0.1-0.8 Ω·m) is identified at mid-crustal depth (8-13 km) in the north Gjallar Ridge from magnetotelluric (MT) data and further investigated in light of other remote-sensing geophysical data (seismic reflection, gravity, aeromagnetic). A commercial 3D controlled-source electromagnetic survey was conducted in the Vøring Basin in 2014 and, although primarily designed for hydrocarbon exploration, good quality MT data were extracted at periods ranging from 100 to 103 s. Dimensionality analysis indicates clear 1D to 2D characteristics in the MT data. 2D inversion was carried out on four profiles (totalling 94 km) oriented perpendicular to the electromagnetic strike and one profile along strike ( 45 km), using a 1D subset of the data. All inversions converged quickly to RMS values close to unity and display a very good agreement with borehole resistivity data from well 6705/10-1 located in the survey area. A striking feature on all profiles is a highly conductive (0.1-0.8 Ω·m) body at 8-13 km depth. To explain the prominent conductive anomaly, integration of geophysical data favours the hypothesis of electrical conduction across well-connected mineral network in pre-Cretaceous sediments. Seismic interpretation suggests a link between the conductor and intruded sedimentary successions below a detachment level and associated low-angle faults. In the Vøring Basin, low magnetic signal and temperature at the conductor's depth indicate that such thick mineral deposits could display non-magnetic behaviour while occurring well below the magnetite Curie isotherm ( 585 °C). Natural occurrences and magnetic properties of common iron-sulphide minerals favour a geological interpretation of mid-crustal conductivity as thick pyrrhotite deposits formed in intrusion's contact metamorphic aureoles.

  7. Families of Keplerian orbits

    Energy Technology Data Exchange (ETDEWEB)

    Butikov, Eugene I [St Petersburg State University, St Petersburg (Russian Federation)

    2003-03-01

    Various properties of Keplerian orbits traced by satellites that are launched from one and the same spatial point with different initial velocities are discussed. Two families of elliptical orbits are investigated, namely the sets of orbits produced by a common direction but different magnitudes of the initial velocities, and by a common magnitude but various directions of the initial velocities. For the latter family, the envelope of all the orbits is found, which is the boundary of the spatial region occupied by the orbits.

  8. Families of Keplerian orbits

    CERN Document Server

    Butikov, E I

    2003-01-01

    Various properties of Keplerian orbits traced by satellites that are launched from one and the same spatial point with different initial velocities are discussed. Two families of elliptical orbits are investigated, namely the sets of orbits produced by a common direction but different magnitudes of the initial velocities, and by a common magnitude but various directions of the initial velocities. For the latter family, the envelope of all the orbits is found, which is the boundary of the spatial region occupied by the orbits.

  9. Orbital fractures: a review

    Directory of Open Access Journals (Sweden)

    Jeffrey M Joseph

    2011-01-01

    Full Text Available Jeffrey M Joseph, Ioannis P GlavasDivision of Ophthalmic Plastic and Reconstructive Surgery, Department of Ophthalmology, School of Medicine, New York University, New York, NY, USA; Manhattan Eye, Ear, and Throat Hospital, New York, NY, USAAbstract: This review of orbital fractures has three goals: 1 to understand the clinically relevant orbital anatomy with regard to periorbital trauma and orbital fractures, 2 to explain how to assess and examine a patient after periorbital trauma, and 3 to understand the medical and surgical management of orbital fractures. The article aims to summarize the evaluation and management of commonly encountered orbital fractures from the ophthalmologic perspective and to provide an overview for all practicing ophthalmologists and ophthalmologists in training.Keywords: orbit, trauma, fracture, orbital floor, medial wall, zygomatic, zygomatic complex, zmc fracture, zygomaticomaxillary complex fractures 

  10. Simultaneous spectroscopy of $\\gamma$- rays and conversion electrons: Systematic study of EO transitions and intruder states in close vicinity of mid-shell point in odd-Au isotopes

    CERN Multimedia

    Venhart, M; Grant, A F; Petrik, K

    This proposal focuses on detailed systematic studies of the $\\beta$ /EC-decays of $^{179,181,183,185}$Hg leading to excited states in the neutron-deficient Au isotopes in the vicinity of the N=104 midshell. $\\gamma$-ray, X-ray and conversion electron de-excitations of odd-A Au isotopes will be studied simultaneously. These studies will address important structural questions such as the excitation energies of coexisting states, properties of multiple intruder states (i.e. intruder particles coupled to intruder cores) and mixing of coexisting structures. The unique combination of Hg beam purity and yields make ISOLDE a unique facility for these experiments.

  11. Neonatal orbital abscess

    Directory of Open Access Journals (Sweden)

    Khalil M Al-Salem

    2014-01-01

    Full Text Available Orbital complications due to ethmoiditis are rare in neonates. A case of orbital abscess due to acute ethmoiditis in a 28-day-old girl is presented. A Successful outcome was achieved following antimicrobial therapy alone; spontaneous drainage of the abscess occurred from the lower lid without the need for surgery. From this case report, we intend to emphasize on eyelid retraction as a sign of neonatal orbital abscess, and to review all the available literature of similar cases.

  12. Family of Orbiters

    Science.gov (United States)

    2008-01-01

    This image shows the paths of three spacecraft currently in orbit around Mars, as well as the path by which NASA's Phoenix Mars Lander will approach and land on the planet. The t-shaped crosses show where the orbiters will be when Phoenix enters the atmosphere, while the x-shaped crosses show their location at landing time. All three orbiters, NASA's Mars Reconnaissance Orbiter, NASA's Mars Odyssey and the European Space Agency's Mars Express, will be monitoring Phoenix during the final steps of its journey to the Red Planet. Phoenix will land just south of Mars's north polar ice cap.

  13. Orbital ordering and frustrations

    NARCIS (Netherlands)

    Khomskii, D.I.; Mostovoy, M.V.

    2003-01-01

    Orbital ordering occurs in many transition metal compounds with Jahn–Teller ions (Cu2+, Mn3+, low-spin Ni3+, Ti3+ etc). It plays an important role in these materials. At the same time, exchange interactions in orbitally degenerate systems are inherently frustrated, even in materials with simple

  14. CONGENITAL ORBITAL TERATOMA

    African Journals Online (AJOL)

    commenced on topical chloramphenicol therapy. The x-ray showed a left orbital soft tissue mass but no orbital enlargement and the swab showed no growth. ... proliferating neural bundles and some neural bundles lined by pigmented choroidal epithelium. Also seen are abundant fibrous tissues scattered within the.

  15. Peripheral orbit model

    CERN Document Server

    Hara, Yasuo

    1975-01-01

    Peripheral orbit model, in which an incoming hadron is assumed to revolve in a peripheral orbit around a target hadron, is discussed. The non-diffractive parts of two-body reaction amplitudes of hadrons are expressed in terms of the radius, width an absorptivity of the orbit. The radius of the orbit is about 1 fm and the width of the orbit is determined by the range of the interaction between the hadrons. The model reproduces all available experimental data on differential cross-sections and polarizations of $K^{-}p\\to K^{-}p$ and $\\bar K^{\\circ}n$ reactions for all angles successfully. This contribution is not included in the proceedings since it will appear in Progress of Theoretical Physics Vol. 51 (1974) No 2. Any person interested in the subject may apply for reprints to the author.

  16. Orbit Stabilization of Nanosat

    Energy Technology Data Exchange (ETDEWEB)

    JOHNSON,DAVID J.

    1999-12-01

    An algorithm is developed to control a pulsed {Delta}V thruster on a small satellite to allow it to fly in formation with a host satellite undergoing time dependent atmospheric drag deceleration. The algorithm uses four short thrusts per orbit to correct for differences in the average radii of the satellites due to differences in drag and one thrust to symmetrize the orbits. The radial difference between the orbits is the only input to the algorithm. The algorithm automatically stabilizes the orbits after ejection and includes provisions to allow azimuthal positional changes by modifying the drag compensation pulses. The algorithm gives radial and azimuthal deadbands of 50 cm and 3 m for a radial measurement accuracy of {+-} 5 cm and {+-} 60% period variation in the drag coefficient of the host. Approaches to further reduce the deadbands are described. The methodology of establishing a stable orbit after ejection is illustrated in an appendix. The results show the optimum ejection angle to minimize stabilization thrust is upward at 86{sup o} from the orbital velocity. At this angle the stabilization velocity that must be supplied by the thruster is half the ejection velocity. An ejection velocity of 0.02 m/sat 86{sup o} gives an azimuthal separation after ejection and orbit stabilization of 187 m. A description of liquid based gas thrusters suitable for the satellite control is included in an appendix.

  17. Orbital cellulitis in children.

    Science.gov (United States)

    Nageswaran, Savithri; Woods, Charles R; Benjamin, Daniel K; Givner, Laurence B; Shetty, Avinash K

    2006-08-01

    To review the epidemiology and management of orbital cellulitis in children. The medical records of children orbital cellulitis and confirmed by computed tomography scan were reviewed. A literature search for additional studies for systematic review was also conducted. Forty-one children with orbital cellulitis were identified. The mean age was 7.5 years (range, 10 months to 16 years), and 30 (73%) were male (male:female ratio = 2.7). All cases of orbital cellulitis were associated with sinusitis; ethmoid sinusitis was present in 40 (98%) patients. Proptosis and/or ophthalmoplegia was documented in 30 (73%), and 34 (83%) had subperiosteal and/or orbital abscesses. Twenty-nine (71%) had surgical drainage and 12 (29%) received antibiotic therapy only. The mean duration of hospitalization was 5.8 days. The mean duration of antibiotic therapy was 21 days. Orbital cellulitis occurs throughout childhood and in similar frequency among younger and older children. It is twice as common among males as females. Selected cases of orbital cellulitis, including many with subperiosteal abscess, can be treated successfully without surgical drainage.

  18. Orbital cystic neurinoma.

    Science.gov (United States)

    Tokugawa, J; Nakao, Y; Mori, K; Maeda, M

    2003-07-01

    A 64-year-old woman presented with a 6-month history of exophthalmus of her right eye. She had no neurological deficit except for the exophthalmus and numbness in the right side of her forehead (frontal nerve territory). Neuro-imaging demonstrated a cystic mass in the right orbit. The tumour was totally removed by microsurgical transcranial surgery. The histological diagnosis was neurinoma. The origin of the tumour was considered to be the frontal nerve. Only two other cases of orbital cystic neurinoma have been reported. This rare clinical entity should be included in the differential diagnosis of a cystic mass in the orbit.

  19. Quark Orbital Angular Momentum

    Directory of Open Access Journals (Sweden)

    Burkardt Matthias

    2015-01-01

    Full Text Available Definitions of orbital angular momentum based on Wigner distributions are used as a framework to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. We find that the difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that change is similar to the mechanism that causes transverse single-spin asymmetries in semi-inclusive deep-inelastic scattering.

  20. Multiple Coulomb excitation of a {sup 70}Ge beam and the interpretation of the 0{sub 2}{sup +} state as a deformed intruder

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, M. [Chiba Institute of Technology, Narashino, Chiba 275-0023 (Japan); Toh, Y.; Oshima, M.; Hayakawa, T.; Hatsukawa, Y.; Katakura, J.; Shinohara, N.; Matsuda, M. [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Czosnyka, T. [Heavy Ion Laboratory, Warsaw University, Warsaw PL-02097 (Poland); Kusakari, H. [Chiba University, Inage-ku, Chiba 263-8522 (Japan); Morikawa, T. [Kyushu University, Hakozaki, Fukuoka 812-8581 (Japan); Seki, A.; Sakata, F. [Department of Mathematical Sciences, Ibaraki University, Mito, Ibaraki 310-8512 (Japan)

    2003-03-01

    Electromagnetic properties of the low-lying states in a {sup 70}Ge nucleus were studied through the multiple Coulomb excitation of a {sup 70}Ge beam with a {sup nat}Pb target. Relative {gamma}-ray intensities were measured as a function of emission angle relative to the scattered projectile. Sixteen E2 matrix elements, including diagonal ones, for 6 low-lying states have been determined using the least-squares search code GOSIA. The expectation values left angle Q{sup 2} right angle of 0{sub 1}{sup +} and 0{sub 2}{sup +} states in {sup 70}Ge are compared with those in {sup 72,} {sup 74,} {sup 76}Ge. Simple mixing calculations indicate that the 0 {sub 2}{sup +} states in {sup 70}Ge and {sup 72}Se can be treated as deformed intruder states. It is shown that the deformed intruder becomes the ground state in {sup 74}Kr. These interpretations of the 0 {sub 2}{sup +} states in this region are compared with the potential-energy surface calculations by the Nilsson-Strutinsky model, which allow to interpret the experimental results in a qualitative way from the theoretical point of view. (orig.)

  1. Congenital orbital teratoma

    Directory of Open Access Journals (Sweden)

    Shereen Aiyub

    2013-01-01

    Full Text Available We present a case of mature congenital orbital teratoma managed with lid-sparing exenteration and dermis fat graft. This is a case report on the management of congenital orbital teratoma. A full-term baby was born in Fiji with prolapsed right globe which was surrounded by a nonpulsatile, cystic mass. Clinical and imaging features were consistent with congenital orbital teratoma. Due to limited surgical expertise, the patient was transferred to Adelaide, Australia for further management. The patient underwent a lid-sparing exenteration with frozen section control of the apical margin. A dermis fat graft from the groin was placed beneath the lid skin to provide volume. Histopathology revealed mature tissues from each of the three germ cell layers which confirmed the diagnosis of mature teratoma. We describe the successful use of demis fat graft in socket reconstruction following lid-sparing exenteration for congenital orbital teratoma.

  2. Orbital heat rate package

    Science.gov (United States)

    Lovin, J. K.; Spradley, L. W.

    1979-01-01

    Package consisting of three separate programs used to accurately predict temperature distribution of spacecraft in planetary orbit is invaluable tool for design and analysis of other structures that must function in complex thermal environment.

  3. Neonatal orbital abscess

    Directory of Open Access Journals (Sweden)

    Pratik Y Gogri

    2015-01-01

    Full Text Available Orbital abscess generally occurs in older children but it can rarely affect infants and neonates too. We report a case of community acquired methicillin resistant staphylococcus aureus (CA-MRSA neonatal orbital abscess in a 12-day-old term female neonate with no significant past medical history or risk factor for developing the infection. The case highlights the importance of consideration of CA-MRSA as a causative agent of neonatal orbital cellulitis even in a neonate without any obvious predisposing condition. Prompt initiation of appropriate medical therapy against MRSA and surgical drainage of the abscess prevents life threatening complications of orbital cellulitis which more often tend to be fatal in neonates.

  4. Orbital interactions in chemistry

    CERN Document Server

    Albright, Thomas A; Whangbo, Myung-Hwan

    2013-01-01

    Explains the underlying structure that unites all disciplines in chemistry Now in its second edition, this book explores organic, organometallic, inorganic, solid state, and materials chemistry, demonstrating how common molecular orbital situations arise throughout the whole chemical spectrum. The authors explore the relationships that enable readers to grasp the theory that underlies and connects traditional fields of study within chemistry, thereby providing a conceptual framework with which to think about chemical structure and reactivity problems. Orbital Interactions

  5. Orbital Cellulitis in a Psoriatic Patient Treated With Adalimumab.

    Science.gov (United States)

    Katana, Vienna G; Carpenter, Robert J; Trafeli, John P; Kwan, Julia M

    2017-03-01

    Psoriatic patients on tumor necrosis factor alpha inhibitors (TNFi) may be at increased risk for upper respiratory tract infections, including chronic rhino-sinusitis (CRS). Rarely, CRS can progress to orbital cellulitis (OC), an emergent ophthalmic complication wherein respiratory flora from paranasal sinus disease intrude the retro-orbital space. Single case report. We report the first case, to our knowledge, of an invasive sinusitis that rapidly evolved into OC in a patient receiving adalimumab treatment for plaque psoriasis and psoriatic arthritis. After TNFi withdrawal and appropriate medical and surgical intervention, the patient fully recovered. However, on resumption of TNFi therapy, symptoms of recalcitrant CRS returned. More investigation is needed to explore how TNFi might predispose to chronic, refractory rhino-sinusitis and subsequent progression to OC. Military physicians and other medical providers should be aware of this proposed new disease entity and the potential for rapidly evolving and invasive infections in immunocompromised patients. Screening and monitoring for chronic infectious disease, such as CRS before initiating and during TNFi therapy is warranted. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.

  6. The Lunar Orbital Prospector

    Science.gov (United States)

    Redd, Frank J.; Cantrell, James N.; McCurdy, Greg

    1992-09-01

    The establishment of lunar bases will not end the need for remote sensing of the lunar surface by orbiting platforms. Human and robotic surface exploration will necessarily be limited to some proximate distance from the support base. Near real-time, high-resolution, global characterization of the lunar surface by orbiting sensing systems will continue to be essential to the understanding of the Moon's geophysical structure and the location of exploitable minerals and deposits of raw materials. The Lunar Orbital Prospector (LOP) is an orbiting sensing platform capable of supporting a variety of modular sensing packages. Serviced by a lunar-based shuttle, the LOP will permit the exchange of instrument packages to meet evolving mission needs. The ability to recover, modify, and rotate sensing packages allows their reuse in varying combinations. Combining this flexibility with robust orbit modification capabilities and near real-time telemetry links provides considerable system responsiveness. Maintenance and modification of the LOP orbit are accomplished through use of an onboard propulsion system that burns lunar-supplied oxygen and aluminum. The relatively low performance of such a system is more than compensated for by the elimination of the need for Earth-supplied propellants. The LOP concept envisions a continuous expansion of capability through the incorporation of new instrument technologies and the addition of platforms.

  7. [Orbital complications of sinusitis].

    Science.gov (United States)

    Šuchaň, M; Horňák, M; Kaliarik, L; Krempaská, S; Koštialová, T; Kovaľ, J

    2014-12-01

    Orbital complications categorised by Chandler are emergency. They need early diagnosis and agresive treatment. Stage and origin of orbital complications are identified by rhinoendoscopy, ophtalmologic examination and CT of orbite and paranasal sinuses. Periorbital cellulitis and early stage of orbital cellulitis can be treated conservatively with i. v. antibiotics. Monitoring of laboratory parameters and ophtalmologic symptoms is mandatory. Lack of improvement or worsening of symptoms within 24-48 hours and advanced stages of orbital complications are indicated for surgery. The purpose of the study is to evaluate epidemiology, clinical features and management of sinogenic orbital complications. Retrospective data of 8 patients with suspicion of orbital complication admited to hospital from 2008 to 2013 were evaluated. Patients were analyzed in terms of gender, age, CT findings, microbiology, clinical features, stage and treatment. Male and female were afected in rate 1,66:1. Most of patients were young adult in 3rd. and 4th. decade of life (62,5 %). Acute and chronic sinusitis were cause of orbital complication in the same rate. The most common origin of orbital complication was ethmoiditis (62,5 %), than maxillary (25 %) and frontal (12,5 %) sinusitis. Polysinusitis with affection of ethmoidal, maxillary and frontal sinuses (75 %) was usual CT finding. Staphylococcus epidermidis and Staphylococcus aureus were etiological agens in half of cases. Periorbital oedema (100 %), proptosis, chemosis (50 %), diplopia and glaucoma (12,5 %) were observed. Based on examinations, diagnosis of periorbital oedema/preseptal cellulitis was made in 3 (37,5 %), orbital cellulitis in 3 (37,5 %) and subperiosteal abscess in 2 cases (25 %). All patients underwent combined therapy - i. v. antibiotics and surgery within 24 hours. Eradication of disease from ostiomeatal complex (OMC), drainage of affected sinuses and drainage of subperiosteal abscess were done via fuctional endonasal

  8. Orbital complications of rhinosinusitis.

    Science.gov (United States)

    Sijuwola, Oo; Adeyemo, Aa; Adeosun, Aa

    2007-06-01

    Suppurative extension of rhinosinusitis to the orbit is a complication that often results from delay in diagnosis and, or inadequate treatment. These complications may range from preseptal cellulitis, orbital cellulitis, orbital abscesses, and subperiosteal abscesses to intracranial extension with a threat to both vision and life. This study aims to review the clinical profile, treatment modalities and outcome of orbital complications of rhinosinusitis in Ibadan, Nigeria. A retrospective review of the charts of patients with orbital complications of rhinosinusitis managed in the departments of Otorhinolaryngology and Ophthalmology, University College Hospital, Ibadan over a five year period (Feb 2002- Jan 2007) was carried out .The diagnosis of rhinosinusitis was based on history, physical examination, plain x ray and CT scan findings and antral puncture. Demographic data, clinical presentation and treatment were evaluated. A total of 24 patients were reviewed in the study. There were 13males and 11females (M/F, 1:1). The age range was 8months to 75years, 14 (58.3%) patients were children and while 10 (41.7%) patients were adults. 75% of the patients were seen during the dry season (November to February). The duration of symptoms ranged from one day to three weeks. Involvement of one eye occurred in 14 patients (58.3%); right eye (4), left eye (10). Both eyes were involved in 10 patients (41.7%). Non-axial proptosis was seen in 8 patients (33.3%). It was infero-lateral in 6 patients (25%) and infero-nasal in two (8.3%) patients. Orbital cellulitis was seen in 10 (41.7%) patients, 6 (25%) patients had preseptal cellulitis while 8 (33%) patients had orbital abscess. Cavernous sinus thrombosis was seen in 3 (12.5%) patients. The cases with preseptal and orbital cellulitis were effectively managed by intravenous antibiotics. Orbital abscesses were drained surgically with complete resolution. Sinus surgical procedures were done in 10(41.7%) patients. This group of

  9. A Tapestry of Orbits

    Science.gov (United States)

    King-Hele, D. G.

    2005-07-01

    Satellites as they cross the night sky look like moving stars, which can be accurately tracked by an observer with binoculars as well as by giant radars and large cameras. These observations help to determine the satellite's orbit, which is sensitive to the drag of the upper atmosphere and to any irregularities in the gravity field of the Earth. Analysis of the orbit can be used to evaluate the density of the upper atmosphere and to define the shape of the Earth. Desmond King-Hele was the pioneer of this technique of orbit analysis, and this book tells us how the research began, before the launch of Sputnik in 1957. For thirty years King-Hele and his colleagues at the Royal Aircraft Establishment, Farnborough, developed and applied the technique to reveal much about the Earth and air at a very modest cost. In the 1960s the upper-atmosphere density was thoroughly mapped out for 100 to 2000 km, revealing immense variation of density with solar activity and between day and night. In the 1970s and 1980s a picture of the upper-atmosphere winds emerged, and the profile of the pear-shaped Earth was accurately charted. The number of satellites now orbiting the earth is over 5000. This book is the story of how this inexpensive research of their orbits developed to yield a rich harvest of knowledge about the Earth and its atmosphere, in a scientific narrative that is enlivened with many personal experiences.

  10. Extended duration orbiter (EDO) insignia

    Science.gov (United States)

    1990-01-01

    Extended duration orbiter (EDO) insignia incorporates a space shuttle orbiter with payload bay doors (PLBDs) open and a spacelab module inside. Trailing the orbiter are the initials EDO. The EDO-modified Columbia, Orbiter Vehicle (OV) 102, will be flown for the first EDO mission, STS-50.

  11. Relative motion of orbiting bodies

    Science.gov (United States)

    Butikov, Eugene I.

    2001-01-01

    A problem of relative motion of orbiting bodies is investigated on the example of the free motion of any body ejected from the orbital station that stays in a circular orbit around the earth. An elementary approach is illustrated by a simulation computer program and supported by a mathematical treatment based on approximate differential equations of the relative orbital motion.

  12. Elliptical Orbit Performance Computer Program

    Science.gov (United States)

    Myler, T.

    1984-01-01

    Elliptical Orbit Performance (ELOPE) computer program for analyzing orbital performance of space boosters uses orbit insertion data obtained from trajectory simulation to generate parametric data on apogee and perigee altitudes as function of payload data. Data used to generate presentation plots that display elliptical orbit performance capability of space booster.

  13. [Secondary orbital lymphoma].

    Science.gov (United States)

    Basanta, I; Sevillano, C; Álvarez, M D

    2015-09-01

    A case is presented of an 85 year-old Caucasian female with lymphoma that recurred in the orbit (secondary ocular adnexal lymphoma). The orbital tumour was a diffuse large B-cell lymphoma according to the REAL classification (Revised European-American Lymphoma Classification). Orbital lymphomas are predominantly B-cell proliferations of a variety of histological types, and most are low-grade tumours. Patients are usually middle-aged or elderly, and it is slightly more common in women. A palpable mass, proptosis and blepharoptosis are the most common signs of presentation. Copyright © 2011 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  14. Preseptal Cellulitis Or Orbital Cellulitis?

    Science.gov (United States)

    Lim, L T; Miller, D; Ah-Kee, E Y; Ferguson, A

    2015-06-29

    Preseptal cellulitis and orbital cellulitis can both present with increasing swelling, tenderness and redness around the eye, but their management differs. Preseptal cellulitis is more common and much less aggressive than orbital cellulitis. In contrast, orbital cellulitis is a medical emergency requiring urgent management. In this article, we provide a systematic approach to distinguish between preseptal cellulitis and orbital cellulitis at presentation, as the distinction between the two entities and the prompt recognition of orbital cellulitis can be potentially life-saving.

  15. Negative-parity intruder states of the neutron-rich N=20, Z=14-16 isotones: a 1{Dirac_h}{omega} shell model description

    Energy Technology Data Exchange (ETDEWEB)

    Bouhelal, M. [Universite de Strasbourg, IPHC, CNRS/IN2P3, Strasbourg (France); Universite de Batna, Departement de Physique, Faculte des Sciences, Batna (Algeria); Haas, F.; Caurier, E.; Nowacki, F. [Universite de Strasbourg, IPHC, CNRS/IN2P3, Strasbourg (France); Bouldjedri, A. [Universite de Batna, Departement de Physique, Faculte des Sciences, Batna (Algeria)

    2009-12-15

    In order to get a consistent shell model description of the negative-parity states throughout the sd shell a new interaction (PSDPFB) has been developed. It was derived in the full p-sd-pf model space and is built on existing interactions for the major shells with adjustments of the cross-shell monopoles. The calculated energy spectra for these 1{Dirac_h}{omega} intruder states are compared to experiment for the N=20 neutron-rich isotones {sup 34}Si, {sup 35}P and {sup 36}S. A systematics for the multiplet configuration {nu}(d{sub 3/2}{sup -1}f{sub 7/2}{sup 1}) in even-even isotones from {sup 34}Si to {sup 40}Ca is also presented. (orig.)

  16. Preliminary orbit determination

    Science.gov (United States)

    Taff, L. G.; Belkin, B.; Schweiter, G.; Sommar, K.

    The problem of intercontinental ballistic missile reentry vehicle orbit determination from incomplete passive (i.e., angles-only) or active (i.e., distance plus angles) information is presented. Launch location and time and impact location and time to complete the computation of an orbital element set are utilized. In addition, it is possible to construct a good estimate of the variance of the key quantity in the angles only case; namely the computed topocentric distance. This type of observation/information situation is enlarged to include a complete discussion of single-point differential correction.

  17. Pediatric Orbital Fractures

    Science.gov (United States)

    Oppenheimer, Adam J.; Monson, Laura A.; Buchman, Steven R.

    2013-01-01

    It is wise to recall the dictum “children are not small adults” when managing pediatric orbital fractures. In a child, the craniofacial skeleton undergoes significant changes in size, shape, and proportion as it grows into maturity. Accordingly, the craniomaxillofacial surgeon must select an appropriate treatment strategy that considers both the nature of the injury and the child's stage of growth. The following review will discuss the management of pediatric orbital fractures, with an emphasis on clinically oriented anatomy and development. PMID:24436730

  18. [Orbital complications of rhinosinusitis].

    Science.gov (United States)

    Stojanović, J; Ilić, N; Belić, B; Zivić, L; Stanković, P; Erdevicki, L; Jovanović, S

    2009-01-01

    Orbital complications were observed in 53 patients (1.35%, n=53/3912 of all treated patients; 11.04%, n= 53/480 of hospitalized patients). Complications in the orbit can occur in 3-5% of adults with the inflammatory condition of sinuses, while the percentage in children ranges from 0.5-8%. The objective of our work was to determine the frequency of the occurence of orbital complications of the rhinosinal inflammatory origin in a group of adults and children. The retrospective analysis of patients treated of rhinosinusitis in the period 1992 to 2007, in the Clinical Center in Kragujevac. In the period of 15 years, a total number of 3912 patients were treated for inflamatory conditions of paranasal cavities. Orbital complications were found in 53 patients (1.35%, n=53/3912 of all treated patients). The number of children showing orbital complications caused by rhinosinusitis was 0.79%, while the number of adults was 1,88%. Acute rhinosinusitis in children was manifested as orbital complication in 14 patients (n=14/15, 93.33%), while 33 adults (n=33/38, 86.84%) had the exarcerbation of the chronic rhinosinusitis at the time of diagnosis of orbital complication. 80% of examined children had the maxillary and ethmoid sinus infected (n=12/15), while the adults most often had polysinusitis (n=22/38, 57.89%). In the juvenile age the most frequent complication was the cellulitis of the orbite (n=7/15, 46.66%), while in the adults it was the subperiostal absces (n=14/38, 36.84%). The adults were mostly treated surgically (n=31/38, 81.58%), while the children were treated by using conservative treatment (n=13/15, 86.67%). There were no cases of mortality. The prevention of complications is based on the adequate and timely treatment of acute sinusitis in children, as well as the curative treatment of chronical processes in adults.

  19. Satellite orbit predictor

    Science.gov (United States)

    Friedman, Morton l.; Garrett, James, Major

    An analog aid to determine satellite coverage of Emergency Locator Transmitters Emergency Position Indicating Radio Beacon (ELT/EPIRB) distress incidence is discussed. The satellite orbit predictor is a graphical aid for determining the relationship between the satellite orbit, antenna coverage of the spacecraft and coverage of the Local User Terminal. The predictor allows the user to quickly visualize if a selected position will probably be detected and is composed of a base map and a satellite track overlay for each satellite.A table of equator crossings for each satellite is included.

  20. The Lunar orbit paradox

    Directory of Open Access Journals (Sweden)

    Tomić Aleksandar S.

    2013-01-01

    Full Text Available Newton's formula for gravity force gives greather force intensity for atraction of the Moon by the Sun than atraction by the Earth. However, central body in lunar (primary orbit is the Earth. So appeared paradox which were ignored from competent specialist, because the most important problem, determination of lunar orbit, was inmediately solved sufficiently by mathematical ingeniosity - introducing the Sun as dominant body in the three body system by Delaunay, 1860. On this way the lunar orbit paradox were not canceled. Vujičić made a owerview of principles of mechanics in year 1998, in critical consideration. As an example for application of corrected procedure he was obtained gravity law in some different form, which gave possibility to cancel paradox of lunar orbit. The formula of Vujičić, with our small adaptation, content two type of acceleration - related to inertial mass and related to gravity mass. So appears carried information on the origin of the Moon, and paradox cancels.

  1. Myxoma of the orbit.

    Directory of Open Access Journals (Sweden)

    Rambhatla Saptagirish

    2003-01-01

    Full Text Available Myxomas are rare, benign neoplasms of mesenchymal origin that usually develop in soft tissues. As the clinical manifestations are non-specific, it is difficult to diagnose the tumour without biopsy and histopathological examination. We report a case of orbital myxoma with histopathological correlation.

  2. A Neptune Orbiter Mission

    Science.gov (United States)

    Wallace, R. A.; Spilker, T. R.

    1998-01-01

    This paper describes the results of new analyses and mission/system designs for a low cost Neptune Orbiter mission. Science and measurement objectives, instrumentation, and mission/system design options are described and reflect an aggressive approach to the application of new advanced technologies expected to be available and developed over the next five to ten years.

  3. Unusual Sclerosing Orbital Pseudotumor Infiltrating Orbits and Maxillofacial Regions

    Directory of Open Access Journals (Sweden)

    Huseyin Toprak

    2014-01-01

    Full Text Available Idiopathic orbital pseudotumor (IOP is a benign inflammatory condition of the orbit without identifiable local or systemic causes. Bilateral massive orbital involvement and extraorbital extension of the IOP is very rare. We present an unusual case of IOP with bilateral massive orbital infiltration extending into maxillofacial regions and discuss its distinctive magnetic resonance imaging (MRI features that help to exclude other entities during differential diagnoses.

  4. Low Earth Orbit Satellite’s Orbit Propagation and Determination

    Science.gov (United States)

    2014-01-01

    Institute of Technology Email: honien.shou@xuite.net Abstract This paper represents orbit propagation and determination of Low Eearth Orbit(LEO...Arichandran, S. H. Tan, T. Bretschneider, High – Presicion Onboard Orbit Determination for Small Satellites - the GPS-Based XNS on X-SAT. 6th Symposium on

  5. Local orbitals by minimizing powers of the orbital variance

    DEFF Research Database (Denmark)

    Jansik, Branislav; Høst, Stinne; Kristensen, Kasper

    2011-01-01

    is obtained. For increasing power exponents, the penalty for delocalized orbitals is increased and smaller maximum orbital spreads are encountered. Calculations on superbenzene, C60, and a fragment of the titin protein show that for a power exponent equal to one, delocalized outlier orbitals may...

  6. Plotting Orbital Trajectories For Maneuvers

    Science.gov (United States)

    Brody, Adam R.

    1991-01-01

    Interactive Orbital Trajectory Planning Tool (EIVAN) computer program is forward-looking interactive orbit-trajectory-plotting software tool for use with proximity operations (operations occurring within 1-km sphere of space station) and other maneuvers. Developed to plot resulting trajectories, to provide better comprehension of effects of orbital mechanics, and to help user develop heuristics for planning missions on orbit. Program runs with Microsoft's Excel for execution on MacIntosh computer running MacIntosh OS.

  7. Preseptal and orbital cellulitis

    Directory of Open Access Journals (Sweden)

    Emine Akçay

    2014-09-01

    Full Text Available Preseptal cellulitis (PC is defined as an inflammation of the eyelid and surrounding skin, whereas orbital cellulitis (OC is an inflammation of the posterior septum of the eyelid affecting the orbit and its contents. Periorbital tissues may become infected as a result of trauma (including insect bites or primary bacteremia. Orbital cellulitis generally occurs as a complication of sinusitis. The most commonly isolated organisms are Staphylococcus aureus, Streptococcus pneumoniae, S. epidermidis, Haempphilus influenzae, Moraxella catarrhalis and S. pyogenes. The method for the diagnosis of OS and PS is computed tomography. Using effective antibiotics is a mainstay for the treatment of PC and OC. There is an agreement that surgical drainage should be performed in cases of complete ophthalmoplegia or significant visual impairment or large abscesses formation. This infections are also at a greater risk of acute visual loss, cavernous sinus thrombosis, meningitis, cerebritis, endophthalmitis, and brain abscess in children. Early diagnosis and appropriate treatment are crucial to control the infection. Diagnosis, treatment, management and complications of PC and OC are summarized in this manuscript. J MicrobiolInfect Dis 2014; 4(3: 123-127

  8. Orbits of four double stars

    Directory of Open Access Journals (Sweden)

    Novaković B.

    2006-01-01

    Full Text Available We present orbits of four double stars. Orbits of stars WDS 23516+4205 = ADS 17050 and WDS 18239+5848 = ADS 11336 were calculated for the first time. Orbits of double stars WDS 02022+3643 = ADS 1613 and WDS 18443+3940 = ADS 11635 were revised. We have also determined their masses, dynamical parallaxes and ephemerides.

  9. Orbital Cellulitis of Odontogenic Origin.

    Science.gov (United States)

    Yan, William; Chakrabarti, Rahul; Choong, Jessica; Hardy, Thomas

    2015-01-01

    Odontogenic orbital cellulitis, although uncommon, has the potential to cause severe vision loss if unsuspected and untreated. Compared to non-odontogenic bacteriology, odontogenic orbital abscesses typically feature a heavy mixed growth with anaerobic organisms. We review the literature and discuss the case of a 26-year-old male who presented with anaerobic orbital cellulitis for treatment.

  10. Retinoblastoma associated orbital cellulitis

    Science.gov (United States)

    Mullaney, P.; Karcioglu, Z.; Huaman, A.; Al-Mesfer, S.

    1998-01-01

    AIM—Preseptal and orbital cellulitis are rare presenting features of intraocular retinoblastoma. The objectives of this study were to determine the frequency of retinoblastoma associated cellulitis, as well as to review its clinical and histopathological features.
METHODS—The medical records of 292 retinoblastoma patients in the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia were reviewed. Those indicating a history of, or presenting with, cellulitis were retrieved and their clinical, radiological, and histopathological variables were assessed. Patients with definite extraocular tumour extension on clinical or radiological examination were excluded.
RESULTS—14 patients were found to have retinoblastoma associated cellulitis (4.8%); nine had bilateral and five had unilateral retinoblastoma. Conjunctival and blood cultures were performed in 10 cases and were negative. 10 children were treated with intravenous steroids, often in conjunction with antibiotics, resulting in a prompt decrease in inflammation. Three other children were treated with antibiotics alone and one received no treatment. Computed tomographic scanning depicted large intraocular tumours occupying between 80% and 100% of the globe in each case. In eight patients, periocular inflammation was radiologically interpreted as possible extraocular extension. In one patient serial computed tomographic scanning showed a reduction in intraocular calcification over time which occurred in the presence of cellulitis. 12 patients underwent enucleation and histopathological examination revealed large necrotic, poorly differentiated tumours associated with uveal involvement and early optic nerve invasion. Focal perilimbal destruction was seen in one patient, and in another peripapillary extrascleral extension was present. 12 patients are alive with a mean follow up of 56.4 months.
CONCLUSIONS—Radiological evaluation of scleral integrity may be hindered by periocular inflammatory

  11. Orbital Cellulitis Following Orbital Blow-out Fracture.

    Science.gov (United States)

    Byeon, Je Yeon; Choi, Hwan Jun

    2017-10-01

    Orbital cellulitis and abscess have been described in the literature as complication that usually occur secondary to infection in the maxillary, ethmoidal, and frontal sinuses. If left untreated, it can lead to blindness, cavernous sinus thrombosis, meningitis, or cerebral abscess. Orbital fractures are a common sequela of blunt orbital trauma, but are only rarely associated with orbital cellulitis. So, the authors present rare orbital cellulitis after orbital blow-out fracture. A 55-year-old Asian complains of severe orbital swelling and pain on the left side. These symptoms had started 2 days earlier and worsened within the 24 hours before hospital admission resulting in visual disturbances such as diplopia and photophobia. Contrast-enhanced computed tomography scan showed considerable soft tissue swelling and abscess formation on the left side. Patient was subjected to surgical drainage under general anesthesia in the operation room. In this case, the postoperative period was uneventful and the rapid improvement of symptoms was remarkable. In conclusion, the abscess of the orbit is a surgical emergency in patients whose impairment of vision or ocular symptoms cannot be controlled with medical therapy using antibiotics. In our case, orbital cellulitis can occur after blunt orbital trauma without predisposing sinusitis. Early and prompt diagnosis and surgical drainage before severe loss of visual acuity rescue or recover the vision in case of orbital cellulitis.

  12. Orbital maneuvers and space rendezvous

    Science.gov (United States)

    Butikov, Eugene I.

    2015-12-01

    Several possibilities of launching a space vehicle from the orbital station are considered and compared. Orbital maneuvers discussed in the paper can be useful in designing a trajectory for a specific space mission. The relative motion of orbiting bodies is investigated on examples of spacecraft rendezvous with the space station that stays in a circular orbit around the Earth. An elementary approach is illustrated by an accompanying simulation computer program and supported by a mathematical treatment based on fundamental laws of physics and conservation laws. Material is appropriate for engineers and other personnel involved in space exploration, undergraduate and graduate students studying classical physics and orbital mechanics.

  13. Orbital Debris: A Policy Perspective

    Science.gov (United States)

    Johnson, Nicholas L.

    2007-01-01

    A viewgraph presentation describing orbital debris from a policy perspective is shown. The contents include: 1) Voyage through near-Earth Space-animation; 2) What is Orbital Debris?; 3) Orbital Debris Detectors and Damage Potential; 4) Hubble Space Telescope; 5) Mir Space Station Solar Array; 6) International Space Station; 7) Space Shuttle; 8) Satellite Explosions; 9) Satellite Collisions; 10) NASA Orbital Debris Mitigation Guidelines; 11) International Space Station Jettison Policy; 12) Controlled/Uncontrolled Satellite Reentries; 13) Return of Space Objects; 14) Orbital Debris and U.S. National Space Policy; 15) U.S Government Policy Strategy; 16) Bankruptcy of the Iridium Satellite System; 17) Inter-Agency Space Debris Coordination Committee (IADC); 18) Orbital Debris at the United Nations; 19) Chinese Anti-satellite System; 20) Future Evolution of Satellite Population; and 21) Challenge of Orbital Debris

  14. Orbit Propagation and Determination of Low Earth Orbit Satellites

    Directory of Open Access Journals (Sweden)

    Ho-Nien Shou

    2014-01-01

    Full Text Available This paper represents orbit propagation and determination of low Earth orbit (LEO satellites. Satellite global positioning system (GPS configured receiver provides position and velocity measures by navigating filter to get the coordinates of the orbit propagation (OP. The main contradictions in real-time orbit which is determined by the problem are orbit positioning accuracy and the amount of calculating two indicators. This paper is dedicated to solving the problem of tradeoffs. To plan to use a nonlinear filtering method for immediate orbit tasks requires more precise satellite orbit state parameters in a short time. Although the traditional extended Kalman filter (EKF method is widely used, its linear approximation of the drawbacks in dealing with nonlinear problems was especially evident, without compromising Kalman filter (unscented Kalman Filter, UKF. As a new nonlinear estimation method, it is measured at the estimated measurements on more and more applications. This paper will be the first study on UKF microsatellites in LEO orbit in real time, trying to explore the real-time precision orbit determination techniques. Through the preliminary simulation results, they show that, based on orbit mission requirements and conditions using UKF, they can satisfy the positioning accuracy and compute two indicators.

  15. Properties of low-lying intruder states in $^{34}$Al and $^{34}$Si sequentially populated in $\\beta$-decay of $^{34}$Mg

    CERN Multimedia

    A low-lying long-lived (26±1 ms) isomer in $^{34}$Al has been observed recently and assigned as 1$^{+}$ state of intruder character. It was populated in $^{36}$S fragmentation and feeds, in $\\beta$-decay, the 0$_{2}^{+}$ state in $^{34}$Si whose excitation energy and lifetime were determined in an electron-positron pairs spectroscopy experiment. In the present experiment we intend to measure for the first time the $\\gamma$-rays following the $\\beta$-decay of $^{34}$Mg. Despite the interest for $^{34}$Mg, the up-right corner of the “N$\\thicksim$20 island of inversion”, the only information on its $\\beta$-decay is the lifetime of 20±10 ms, determined from $\\beta$-neutron coincidences. As a result of the proposed experiment, we expect to place the first transitions in the level scheme of $^{34}$Al and to strongly populate the newly observed isomer, measuring its excitation energy, if the branching ratio to 4$^{−}$ ground state is significant. Theoretical estimations for the $\\beta$-decay of the new isome...

  16. Intruder dose pathway analysis for the onsite disposal of radioactive wastes: the ONSITE/MAXI1 computer program. Supplement No. 1

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, W.E. Jr.; Peloquin, R.A.; Napier, B.A.; Neuder, S.M.

    1986-05-01

    The document entitled Intruder Dose Pathway Analysis of the Onsite Disposal of Radioactive Wastes: The ONSITE/MAXI1 Computer Program (1984) summarizes initial efforts to develop human-intrustion scenarios and a modified version of the MAXI computer program for potential use by the NRC in reviewing applications for onsite radioactive waste disposal. This document is a supplement to that document and summarizes efforts to further modify and improve the ONSITE/MAXI1 software package. To facilitate cross-referencing, it follows the same format. Notable improvements to the software package include the capability to account for shielding conditions that represent noncompacted trash wastes and the option to indicate alternative land-use condition;s. This supplement contains a description of the implementation of these modifications. In addition, a series of discussions are included in an attempt to increase the user's understanding of the scenarios and dose calculation methods. These discussions respond to frequently asked questions about the mathematical models and use of the software. Computer listings of the ONSITE/MAXI1 computer program are included as Appendices A and B of this document. Appendix C lists external exposure dose-rate factor libraries.

  17. Geo satellite attitude and orbit control: fixed orbit control thrasters

    OpenAIRE

    Ermoshkin, Yu; V. Raevsky; Urusov, V.

    2009-01-01

    The paper describes the enhanced application ofhigh-economical electro-jet orbit control thrusters for geostationary satellites; in particular, generation of controlling moments to the benefit of satellite attitude determination and control subsystems in the course of orbit control maneuvers ongoing. The scheme with thrusters fixed on a satellite body is analyzed. Possible orbit control session procedures are proposed on the basis of controlling moments generation. Advantages and disadvantage...

  18. A Typical Presentation of Orbital Pseudotumor Mimicking Orbital Cellulitis

    Directory of Open Access Journals (Sweden)

    J. Ayatollahi

    2013-10-01

    Full Text Available Introduction: Orbital pseudotumor, also known as idiopathic orbital inflammatory syndrome (IOIS, is a benign, non- infective inflammatory condition of the orbit without identifiable local or systemic causes. The disease may mimics a variety of pathologic conditions. We pre-sent a case of pseudotumor observed in a patient admitted under the name of orbital celluli-ties. Case Report: A 26-year-old woman reffered to our hospital with the history of left ocular pain and headache 2 days before her visit.. Ophthalmological examination of the patient was normal except for the redness and lid edema, mild chemosis and conjunctival injection. Gen-eral assessment was normal but a low grade fever was observed. She was hospitalized as an orbital cellulitis patient. She was treated with intravenous antibiotics. On the third day , sud-denly diplopia, proptosis in her left eye and ocular pain in her right side appeared. MRI re-vealed bilateral enlargement of extraocular muscles. Diagnosis of orbital pseudotumor was made and the patient was treated with oral steroid.She responded promptly to the treatment. Antibiotics were discontinued and steroid was tapered in one month period under close fol-low up. Conclusion: The clinical features of orbital pseudotumor vary widely . Orbital pseudotumor and orbital cellulitis can occasionally demonstrate overlapping features.. Despite complete physical examination and appropriate imaging, sometimes correct diagnosis of the disease would be difficult (Sci J Hamadan Univ Med Sci 2013; 20 (3:256-259

  19. Herschel-HIFI observations of high-J CO and isotopologues in star-forming regions: from low to high mass

    Science.gov (United States)

    San José-García, I.; Mottram, J. C.; Kristensen, L. E.; van Dishoeck, E. F.; Yıldız, U. A.; van der Tak, F. F. S.; Herpin, F.; Visser, R.; McCoey, C.; Wyrowski, F.; Braine, J.; Johnstone, D.

    2013-05-01

    Context. Our understanding of the star formation process has traditionally been confined to certain mass or luminosity boundaries because most studies focus only on low-, intermediate-, or high-mass star-forming regions. Therefore, the processes that regulate the formation of these different objects have not been effectively linked. As part of the "Water In Star-forming regions with Herschel" (WISH) key programme, water and other important molecules, such as CO and OH, have been observed in 51 embedded young stellar objects (YSOs). The studied sample covers a range of luminosities from 105L⊙. Aims: We analyse the CO line emission towards a large sample of embedded protostars in terms of both line intensities and profiles. This analysis covers a wide luminosity range in order to achieve better understanding of star formation without imposing luminosity boundaries. In particular, this paper aims to constrain the dynamics of the environment in which YSOs form. Methods: Herschel-HIFI spectra of the 12CO J = 10-9, 13CO J = 10-9 and C18O J = 5-4, J = 9-8 and J = 10-9 lines were analysed for a sample of 51 embedded protostars. In addition, JCMT spectra of 12CO J = 3-2 and C18O J = 3-2 extend this analysis to cooler gas components. We focussed on characterising the shape and intensity of the CO emission line profiles by fitting the lines with one or two Gaussian profiles. We compared the values and results of these fits across the entire luminosity range covered by WISH observations. The effects of different physical parameters as a function of luminosity and the dynamics of the envelope-outflow system were investigated. Results: All observed CO and isotopologue spectra show a strong linear correlation between the logarithms of the line and bolometric luminosities across six orders of magnitude on both axes. This suggests that the high-J CO lines primarily trace the amount of dense gas associated with YSOs and that this relation can be extended to larger (extragalactic

  20. New Orbits for 18 Binaries

    Science.gov (United States)

    Cvetković, Z.; Pavlović, R.

    2017-12-01

    Orbital elements of 18 visual binaries are computed using the measurements collected in the Fourth Catalog of Interferometric Measurements of Binary Stars; 15 orbits are determined for the first time and three orbits are revised. Eleven of the binaries, denoted as HDS, were discovered during the Hipparcos mission. The remaining binaries were discovered a few years earlier or later than 1991. All studied pairs are close, and all measured separations are less than 0\\buildrel{\\prime\\prime}\\over{.} 46. The shortest orbital period is 10 years and the longest orbital period is 127 years. Dynamical parallaxes and total masses of systems are derived from the orbital elements. We also give absolute magnitudes, spectral types, and (O-C) residuals in θ and ρ.

  1. Orbital science's 'Bermuda Triangle'

    Science.gov (United States)

    Sherrill, Thomas J.

    1991-02-01

    The effects of a part of the inner Van Allen belt lying closest to the earth, known as the South Atlantic Anomaly (SAA) upon spacecraft including the Hubble Space Telescope (HST), are discussed. The area consists of positively charged ions and electrons from the Van Allen Belt which become trapped in the earth's dipole field. Contor maps representing the number of protons per square centimeter per second having energies greater than 10 million electron volts are presented. It is noted that the HST orbit causes it to spend about 15 percent of its time in the SAA, but that, unlike the experience with earlier spacecraft, the satellite's skin, internal structure, and normal electronic's packaging provides sufficient protection against eletrons, although some higher energy protons still get through. Various charged particle effects which can arise within scientific instruments including fluorescence, Cerenkov radiation, and induced radioactivity are described.

  2. Orbital Eccrine Hidrocystoma

    Directory of Open Access Journals (Sweden)

    Deniz Marangoz

    2016-10-01

    Full Text Available A 29-year-old female patient presented with a painless mass on her upper eyelid medially. She noticed the mass 4 years earlier and it had increased in size over time. She had no diplopia, eyelid swelling, skin lesion overlying the mass, or visual disturbances. On ocular examination, eye movements and funduscopy were normal. The mass was movable and painless with palpation. Magnetic resonance imaging with contrast showed a 12x8x7 mm well-circumscribed cystic lesion with no contrast dye appearance. Surgical removal was performed delicately and no capsular rupture occured. Pathological examination revealed an eccrine hidrocystoma. Our aim is to underline that eccrine hidrocystoma should be included in differential diagnosis of orbital masses.

  3. The conservation of orbital symmetry

    CERN Document Server

    Woodward, R B

    2013-01-01

    The Conservation of Orbital Symmetry examines the principle of conservation of orbital symmetry and its use. The central content of the principle was that reactions occur readily when there is congruence between orbital symmetry characteristics of reactants and products, and only with difficulty when that congruence does not obtain-or to put it more succinctly, orbital symmetry is conserved in concerted reaction. This principle is expected to endure, whatever the language in which it may be couched, or whatever greater precision may be developed in its application and extension. The book ope

  4. CDDIS_DORIS_products_orbit

    Data.gov (United States)

    National Aeronautics and Space Administration — Precise satellite orbits derived from analysis of Doppler Orbitography by Radiopositioning Integrated on Satellite (DORIS) data. These products are the generated by...

  5. Orbital Evolution and Orbital Phase Resolved Spectroscopy of the ...

    Indian Academy of Sciences (India)

    tra in the 3–20 keV energy range were fitted with a power law and a high ... acceleration method and also depends on any anisotropy in the stellar wind structure. .... Orbital Evolution and Orbital Phase Resolved Spectroscopy. 415. Figure 3. (a) Pulse arrival time delays measured from the RXTE-PCA observation in 2003,.

  6. Orbital Chondroma: A rare mesenchymal tumor of orbit

    Directory of Open Access Journals (Sweden)

    Ruchi S Kabra

    2015-01-01

    Full Text Available While relatively common in the skeletal system, cartilaginous tumors are rarely seen originating from the orbit. Here, we report a rare case of an orbital chondroma. A 27-year-old male patient presented with a painless hard mass in the superonasal quadrant (SNQ of left orbit since 3 months. On examination, best-corrected visual acuity of both eyes was 20/20, with normal anterior and posterior segment with full movements of eyeballs and normal intraocular pressure. Computerized tomography scan revealed well defined soft tissue density lesion in SNQ of left orbit. Patient was operated for anteromedial orbitotomy under general anesthesia. Mass was excised intact and sent for histopathological examination (HPE. HPE report showed lobular aggregates of benign cartilaginous cells with mild atypia suggesting of benign cartilaginous tumor - chondroma. Very few cases of orbital chondroma have been reported in literature so far.

  7. Plasmablastic lymphoma mimicking orbital cellulitis.

    NARCIS (Netherlands)

    Barkhuysen, R.; Merkx, M.A.W.; Weijs, W.L.J.; Gerlach, N.L.; Berge, S.J.

    2008-01-01

    INTRODUCTION: Orbital cellulitis is an uncommon, potentially devastating condition that, when not promptly and adequately treated, can lead to serious sequelae. The presenting clinical signs are proptosis, swelling, ophthalmoplegia, pain and redness of the peri-orbital tissues. A number of cases

  8. Diffractive molecular-orbital tomography

    Science.gov (United States)

    Zhai, Chunyang; Zhu, Xiaosong; Lan, Pengfei; Wang, Feng; He, Lixin; Shi, Wenjing; Li, Yang; Li, Min; Zhang, Qingbin; Lu, Peixiang

    2017-03-01

    High-order-harmonic generation in the interaction of femtosecond lasers with atoms and molecules opens the path to molecular-orbital tomography and to probe the electronic dynamics with attosecond-Ångström resolutions. Molecular-orbital tomography requires both the amplitude and phase of the high-order harmonics. Yet the measurement of phases requires sophisticated techniques and represents formidable challenges at present. Here we report a scheme, called diffractive molecular-orbital tomography, to retrieve the molecular orbital solely from the amplitude of high-order harmonics without measuring any phase information. We have applied this method to image the molecular orbitals of N2, CO2, and C2H2 . The retrieved orbital is further improved by taking account the correction of Coulomb potential. The diffractive molecular-orbital tomography scheme, removing the roadblock of phase measurement, significantly simplifies the molecular-orbital tomography procedure and paves an efficient and robust way to the imaging of more complex molecules.

  9. Orbit Modeller - Virtual Astronomical Laboratory

    Science.gov (United States)

    Avdyushev, V. A.; Banshchikova, M. A.; Bordovitsyna, T. V.; Chuvashov, I. N.; Ryabova, G. O.

    2017-09-01

    We present a virtual astronomical laboratory project - "Orbit Modeller" (OM). This should be an interactive web-tool enabling one to simulate numerically the orbital motion of any celestial body within or beyond the solar system. Another function of OM is a repository of old observations and documents.

  10. Endoscopic treatment of orbital tumors.

    Science.gov (United States)

    Signorelli, Francesco; Anile, Carmelo; Rigante, Mario; Paludetti, Gaetano; Pompucci, Angelo; Mangiola, Annunziato

    2015-03-16

    Different orbital and transcranial approaches are performed in order to manage orbital tumors, depending on the location and size of the lesion within the orbit. These approaches provide a satisfactory view of the superior and lateral aspects of the orbit and the optic canal but involve risks associated with their invasiveness because they require significant displacement of orbital structures. In addition, external approaches to intraconal lesions may also require deinsertion of extraocular muscles, with subsequent impact on extraocular mobility. Recently, minimally invasive techniques have been proposed as valid alternative to external approaches for selected orbital lesions. Among them, transnasal endoscopic approaches, "pure" or combined with external approaches, have been reported, especially for intraconal lesions located inferiorly and medially to the optic nerve. The avoidance of muscle detachment and the shortness of the surgical intraorbital trajectory makes endoscopic approach less invasive, thus minimizing tissue damage. Endoscopic surgery decreases the recovery time and improves the cosmetic outcome not requiring skin incisions. The purpose of this study is to review and discuss the current surgical techniques for orbital tumors removal, focusing on endoscopic approaches to the orbit and outlining the key anatomic principles to follow for safe tumor resection.

  11. Generating realistic synthetic meteoroid orbits

    Science.gov (United States)

    Vida, Denis; Brown, Peter G.; Campbell-Brown, Margaret

    2017-11-01

    Context. Generating a synthetic dataset of meteoroid orbits is a crucial step in analysing the probabilities of random grouping of meteoroid orbits in automated meteor shower surveys. Recent works have shown the importance of choosing a low similarity threshold value of meteoroid orbits, some pointing out that the recent meteor shower surveys produced false positives due to similarity thresholds which were too high. On the other hand, the methods of synthetic meteoroid orbit generation introduce additional biases into the data, thus making the final decision on an appropriate threshold value uncertain. Aims. As a part of the ongoing effort to determine the nature of meteor showers and improve automated methods, it was decided to tackle the problem of synthetic meteoroid orbit generation, the main goal being to reproduce the underlying structure and the statistics of the observed data in the synthetic orbits. Methods. A new method of generating synthetic meteoroid orbits using the Kernel Density Estimation method is presented. Several types of approaches are recommended, depending on whether one strives to preserve the data structure, the data statistics or to have a compromise between the two. Results. The improvements over the existing methods of synthetic orbit generation are demonstrated. The comparison between the previous and newly developed methods are given, as well as the visualization tools one can use to estimate the influence of different input parameters on the final data.

  12. Density-orbital embedding theory

    NARCIS (Netherlands)

    Visscher, L.; Gritsenko, O.

    2010-01-01

    In the article density-orbital embedding (DOE) theory is proposed. DOE is based on the concept of density orbital (DO), which is a generalization of the square root of the density for real functions and fractional electron numbers. The basic feature of DOE is the representation of the total

  13. Measuring Scars of Periodic Orbits

    CERN Document Server

    Kaplan, L

    1999-01-01

    The phenomenon of periodic orbit scarring of eigenstates of classically chaotic systems is attracting increasing attention. Scarring is one of the most important ``corrections'' to the ideal random eigenstates suggested by random matrix theory. This paper discusses measures of scars and in so doing also tries to clarify the concepts and effects of eigenfunction scarring. We propose a new, universal scar measure which takes into account an entire periodic orbit and the linearized dynamics in its vicinity. This measure is tuned to pick out those structures which are induced in quantum eigenstates by unstable periodic orbits and their manifolds. It gives enhanced scarring strength as measured by eigenstate overlaps and inverse participation ratios, especially for longer orbits. We also discuss off-resonance scars which appear naturally on either side of an unstable periodic orbit.

  14. Plasmablastic lymphoma mimicking orbital cellulitis

    Science.gov (United States)

    Merkx, Matthias A. W.; Weijs, Willem L. J.; Gerlach, Niek L.; Bergé, Stefaan J.

    2008-01-01

    Introduction Orbital cellulitis is an uncommon, potentially devastating condition that, when not promptly and adequately treated, can lead to serious sequelae. The presenting clinical signs are proptosis, swelling, ophthalmoplegia, pain and redness of the peri-orbital tissues. A number of cases have been reported in which these symptoms have been mistakenly interpreted as being secondary to an orbital infection whilst, in fact, other pathology was present. Discussion We add another case in which, on clinical grounds and after radiological assessment and laboratory tests, a working diagnosis of orbital cellulitis of the left eye was made. It was only after histopathological analysis of a soft tissue specimen from the maxillary sinus that a diagnosis of an AIDS-related plasmablastic lymphoma was made. The patient was referred to the department of haematology where chemotherapeutic treatment for the lymphoma and the HIV infection was started. This case report adds another differential diagnosis of orbital cellulitis to the existing literature. PMID:18597126

  15. Rehabilitation of orbital cavity after orbital exenteration using polymethyl methacrylate orbital prosthesis

    Directory of Open Access Journals (Sweden)

    Sumeet Jain

    2016-01-01

    Full Text Available Squamous cell carcinoma of the eyelid is the second most common malignant neoplasm of the eye with the incidence of 0.09 and 2.42 cases/100 000 people. Orbital invasion is a rare complication but, if recognized early, can be treated effectively with exenteration. Although with advancements in technology such as computer-aided design and computer-aided manufacturing, material science, and retentive methods like implants, orbital prosthesis with stock ocular prosthesis made of methyl methacrylate retained by anatomic undercuts is quiet effective and should not be overlooked and forgotten. This clinical report describes prosthetic rehabilitation of two male patients with polymethyl methacrylate resin orbital prosthesis after orbital exenteration, for squamous cell carcinoma of the upper eyelid. The orbital prosthesis was sufficiently retained by hard and soft tissue undercuts without any complications. The patients using the prosthesis are quite satisfied with the cosmetic results and felt comfortable attending the social events.

  16. Orbital Infarction due to Sickle Cell Disease without Orbital Pain

    Directory of Open Access Journals (Sweden)

    Cameron L. McBride

    2016-01-01

    Full Text Available Sickle cell disease is a hemoglobinopathy that results in paroxysmal arteriolar occlusion and tissue infarction that can manifest in a plurality of tissues. Rarely, these infarcted crises manifest in the bony orbit. Orbital infarction usually presents with acute onset of periorbital tenderness, swelling, erythema, and pain. Soft tissue swelling can result in proptosis and attenuation of extraocular movements. Expedient diagnosis of sickle cell orbital infarction is crucial because this is a potentially sight-threatening entity. Diagnosis can be delayed since the presentation has physical and radiographic findings mimicking various infectious and traumatic processes. We describe a patient who presented with sickle cell orbital crisis without pain. This case highlights the importance of maintaining a high index of suspicion in patients with known sickle cell disease or of African descent born outside the United States in a region where screening for hemoglobinopathy is not routine, even when the presentation is not classic.

  17. SPHERES Mars Orbiting Sample Return External Orbiting Capture Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's Mars Sample Return (MSR) mission scenario utilizes a small Orbiting Sample (OS) satellite, launched from the surface of Mars, which will rendezvous with an...

  18. JSC Orbital Debris Website Description

    Science.gov (United States)

    Johnson, Nicholas L.

    2006-01-01

    Purpose: The website provides information about the NASA Orbital Debris Program Office at JSC, which is the lead NASA center for orbital debris research. It is recognized world-wide for its leadership in addressing orbital debris issues. The NASA Orbital Debris Program Office has taken the international lead in conducting measurements of the environment and in developing the technical consensus for adopting mitigation measures to protect users of the orbital environment. Work at the center continues with developing an improved understanding of the orbital debris environment and measures that can be taken to control its growth. Major Contents: Orbital Debris research is divided into the following five broad efforts. Each area of research contains specific information as follows: 1) Modeling - NASA scientists continue to develop and upgrade orbital debris models to describe and characterize the current and future debris environment. Evolutionary and engineering models are described in detail. Downloadable items include a document in PDF format and executable software. 2) Measurements - Measurements of near-Earth orbital debris are accomplished by conducting ground-based and space-based observations of the orbital debris environment. The data from these sources provide validation of the environment models and identify the presence of new sources. Radar, optical and surface examinations are described. External links to related topics are provided. 3) Protection - Orbital debris protection involves conducting hypervelocity impact measurements to assess the risk presented by orbital debris to operating spacecraft and developing new materials and new designs to provide better protection from the environment with less weight penalty. The data from this work provides the link between the environment defined by the models and the risk presented by that environment to operating spacecraft and provides recommendations on design and operations procedures to reduce the risk as

  19. High Power Orbit Transfer Vehicle

    National Research Council Canada - National Science Library

    Gulczinski, Frank

    2003-01-01

    ... from Virginia Tech University and Aerophysics, Inc. to examine propulsion requirements for a high-power orbit transfer vehicle using thin-film voltaic solar array technologies under development by the Space Vehicles Directorate (dubbed PowerSail...

  20. Management of odontogenic orbital cellulitis.

    Science.gov (United States)

    DeCroos, F C; Liao, J C; Ramey, N A; Li, I

    2011-08-15

    This work describes a series of patients with odontogenic orbital cellulitis (OOC), focusing on rate of abscess formation, need for surgical intervention, and imaging findings helpful for rapid diagnosis. Review of a current case and 22 patients with OOC from the scientific literature demonstrated periapical lucency as the most commonly (36.4%) reported finding on facial and orbital computerized tomography (CT) scan. Orbital abscess occurred in 72.7% of cases, and tooth extraction and/or abscess drainage was required in 95.5% of cases reviewed for control of infection. The current case presented with periapical lucency on CT scan, developed orbital abscess despite broad spectrum antibiotic therapy, and required multiple surgical interventions for disease resolution. Though our patient regained excellent vision, OOC often can result in severe vision loss. Periapical lucency on CT can help identify this atypical origin of cellulitis that is strongly associated with abscess formation and need for surgical intervention.

  1. Orbital operations study. Executive summary

    Science.gov (United States)

    Hogan, L. R.

    1972-01-01

    A summary of the analyses of the orbital operations study is presented. Objectives, scope of study, and technical documentation format are discussed. A summary of the mission analyses including generic mission models, element pair interactions, and interfacing activities are presented. The analyses associated with each interfacing activity are also summarized. Significant implications derived during the course of the study on the EOS orbiter, space tug, RAM, and MSS are indicated.

  2. Microbiological profile of orbital abscess

    Directory of Open Access Journals (Sweden)

    N Suneetha

    2012-01-01

    Full Text Available Background: Knowledge of the culture and sensitivity pattern is necessary, for the institution of appropriate empirical antibiotic therapy in orbital abscess. Objective: The objective of this study is to describe culture and sensitivity patterns of specimens from the orbit and surrounding structures. Materials and Methods: Retrospectively the medical records of 56 cases of orbital abscess were reviewed. Results: Cultures were positive in 38/56 (68.8% orbital specimens and the organisms included Staphylococcus aureus 18, Streptococci 7, Pseudomonas aeruginosa 3, 2 each of Enterobactersp, Escherichia coli, Proteus mirabilis, Acinetobacter sp. and 1 each of Actinomyces israelii, Diptheroids, Coagulase negative Staphylococcus, Citrobacter freundii, Methicillin-resistant S. aureus and Enterococcus faecalis. Four had polymicrobial infection. Culture of purulent nasal discharge, swabs taken from foci of infection on the face, and blood cultures were done in 26/56, and positive cultures were obtained in 16/26 (61.5% specimens. In 12 patients, there was a concurrence in the organism cultured from the orbit and from cultures from other sites. Gram-negative organisms were associated with increased ocular morbidity. Conclusion: Gram-positive cocci, especially S. aureus are the most common organisms isolated from orbital abscesses. Infections by Gram-negative organisms were associated with more complications. Empirical intravenous antibiotic therapy should have a broad spectrum of activity effective against a wide range of Staphylococcal organisms and Gram-negative bacilli.

  3. Space Tourism: Orbital Debris Considerations

    Science.gov (United States)

    Mahmoudian, N.; Shajiee, S.; Moghani, T.; Bahrami, M.

    2002-01-01

    Space activities after a phase of research and development, political competition and national prestige have entered an era of real commercialization. Remote sensing, earth observation, and communication are among the areas in which this growing industry is facing competition and declining government money. A project like International Space Station, which draws from public money, has not only opened a window of real multinational cooperation, but also changed space travel from a mere fantasy into a real world activity. Besides research activities for sending man to moon and Mars and other outer planets, space travel has attracted a considerable attention in recent years in the form of space tourism. Four countries from space fairing nations are actively involved in the development of space tourism. Even, nations which are either in early stages of space technology development or just beginning their space activities, have high ambitions in this area. This is worth noting considering their limited resources. At present, trips to space are available, but limited and expensive. To move beyond this point to generally available trips to orbit and week long stays in LEO, in orbital hotels, some of the required basic transportations, living requirements, and technological developments required for long stay in orbit are already underway. For tourism to develop to a real everyday business, not only the price has to come down to meaningful levels, but also safety considerations should be fully developed to attract travelers' trust. A serious hazard to space activities in general and space tourism in particular is space debris in earth orbit. Orbiting debris are man-made objects left over by space operations, hazardous to space missions. Since the higher density of debris population occurs in low earth orbit, which is also the same orbit of interest to space tourism, a careful attention should be paid to the effect of debris on tourism activities. In this study, after a

  4. Triple Difference Approach to Low Earth Orbiter Precision Orbit Determination

    Science.gov (United States)

    Kwon, Jay-Hyoun; Grejner-Brzezinska, Dorota A.; Yom, Jae-Hong; Cheon, Lee-Dong

    2003-03-01

    A precise kinematic orbit determination (P-KOD) procedure for Low Earth Orbiter(LEO) using the GPS ion-free triple differenced carrier phases is presented. Because the triple differenced observables provide only relative information, the first epoch's positions of the orbit should be held fixed. Then, both forward and backward filtering was executed to mitigate the effect of biases of the first epoch's position. P-KOD utilizes the precise GPS orbits and ground stations data from International GPS Service (IGS) so that the only unknown parameters to be solved are positions of the satellite at each epoch. Currently, the 3-D accuracy of P-KOD applied to CHAMP (CHAllenging Minisatellite Payload) shows better than 35 cm compared to the published rapid scientific orbit (RSO) solution from GFZ (GeoForschungsZentrum Potsdam). The data screening for cycle slips is a particularly challenging procedure for LEO, which moves very fast in the middle of the ionospheric layer. It was found that data screening using SNR (signal to noise ratio) generates best results based on the residual analysis using RSO. It is expected that much better accuracy are achievable with refined prescreening procedure and optimized geometry of the satellites and ground stations.

  5. Orbital, subconjunctival, and subcutaneous emphysema after an orbital floor fracture

    Directory of Open Access Journals (Sweden)

    Ababneh OH

    2013-06-01

    Full Text Available Osama H Ababneh Department of Ophthalmology, The University of Jordan and Jordan University Hospital, Amman, Jordan Abstract: A 16-year-old boy presented to the emergency department with the complaint of a sudden, painful left eye and proptosis after an episode of sneezing. A few hours earlier, he had sustained a blunt trauma to the left orbit as the result of a fistfight. The initial examination showed subcutaneous and subconjunctival emphysema. Visual acuity in the left eye was 20/30 (0.67, the pupils were reactive with no relative afferent pupillary defect, and there were mild limitations in levoduction and supraduction. A slit-lamp examination showed normal anterior and posterior segments with an intraocular pressure of 26 mmHg. An orbital computed tomography scan showed orbital, subconjunctival, and subcutaneous emphysema associated with a small fracture of the orbital floor. Following conservative management with broad-spectrum oral antibiotics, a topical antiglaucoma drug, and lubricating eye drops, the patient improved dramatically within one week. Keywords: emphysema, orbital fracture, trauma

  6. Thermal alteration of terrestrial palynomorphs in mid-Cretaceous organic-rich mudstones intruded by an igneous sill (Newfoundland Margin, ODP Hole 1276A)

    Energy Technology Data Exchange (ETDEWEB)

    Pross, Joerg; Schellenberg, Franziska [Institute of Geosciences, University of Frankfurt, Senckenberganlage 32-34, D-60054 Frankfurt (Germany); Pletsch, Thomas; Kus, Jolanta [Federal Institute for Geosciences and Natural Resources, Stilleweg 2, D-30655 Hannover (Germany); Shillington, Donna J. [School of Earth and Ocean Science, National Oceanography Centre Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH (United Kingdom); Ligouis, Bertrand [Laboratories for Applied Organic Petrology, Sigwartstr. 10, D-72076 Tuebingen (Germany)

    2007-05-01

    Most approaches used to reconstruct thermal alteration of sediments necessitate advanced, relatively expensive analytical techniques. We have evaluated the fidelity of a less costly, relatively simple approach of visually assessing sporomorph colours to determine thermal alteration. The sporomorph-based thermal alteration estimates were compared to vitrinite reflectance data from the same samples. As study material, we selected a succession of mid-Cretaceous (Albian) organic-rich clay- and siltstones intruded by a diabase sill that was recovered from Ocean Drilling Program (ODP) Hole 1276A, off Newfoundland. Six sporomorph groups (SG), each consisting of morphologically well-defined, easily identifiable constituents with long stratigraphic ranges, were individually evaluated for their thermal alteration signals. These groups are: (1) leiotrilete spores of the genera Biretisporites, Cyathidites, Deltoidospora, Dictyophyllidites, Gleicheniidites, and Leiotriletes (SG-1; subdivided into three subgroups SG-1a, SG-1b and SG-1c with sporoderm thicknesses < 1 {mu}m, 1-1.5 {mu}m and > 1.5 {mu}m, respectively); (2) trilete, rugulate spores of the genera Camerozonosporites and Lycopodiacidites (SG-2); (3) trilete, striate spores of the genera Appendicisporites, Cicatricosisporites and Plicatella (SG-3); and (4) the gymnosperm-pollen taxon Classopollis torosus (SG-4). Sporomorph colours were determined using Munsell colour standards under reproducible optical conditions. To minimize the potential influence of reworked specimens on the dataset, only the lightest 50% of all counted specimens per sporomorph group were evaluated for their thermal alteration signals. The thermal alteration estimates from all sporomorph groups yield an internally consistent picture that is compatible with vitrinite reflectance data from the same samples. They indicate that downhole thermal alteration does not increase until 20 m above the igneous sill. A steep rise occurs only at 4.23 m above the

  7. Microbiology of pediatric orbital cellulitis.

    Science.gov (United States)

    McKinley, Steven H; Yen, Michael T; Miller, Aaron M; Yen, Kimberly G

    2007-10-01

    To evaluate the microbiology of pediatric orbital cellulitis associated with sinusitis. Retrospective review of medical records of pediatric patients treated for orbital cellulitis. All pediatric patients treated for orbital cellulitis associated with sinusitis at Texas Children's Hospital between December 1, 2001 and September 30, 2005 were reviewed. Data collected included patient age, history, microbiology results, and surgical intervention. Thirty-eight cases were identified. Fifteen cases required medical management, whereas 23 patients received a combination of medical and surgical intervention. Three patients had multiple surgical procedures performed. Of the procedures performed, four were sinus irrigation, 12 were sinusotomy and drainage, nine were orbitotomy with drainage of abscess, and one was craniotomy with drainage of abscess. Surgical aspirate specimens yielded a higher positive culture result rate with 9/9 of orbital abscesses and 13/16 of sinus aspirates demonstrating a positive yield. Two of the 27 blood cultures had a positive yield. Staphylococcus species was the most common organism isolated. Methicillin-resistant S. aureus (MRSA) represented 73% of S. aureus isolates. Streptococcus species was the next most common pathogen. Three cultures yielded Haemophilus species with one being positive for H. influenzae. Organisms responsible for causing pediatric orbital cellulitis are evolving, with Staphylococcus followed by Streptococcus species being the most common pathogens. The occurrence of MRSA in pediatric orbital cellulitis is increasing, and empiric antimicrobial therapy should be directed against these organisms if they are prevalent in the community. Sinus and orbital abscess aspirates yielded the greatest number of positive cultures, though these invasive surgical procedures should be performed only when clinically indicated.

  8. Featured Image: Globular Cluster Orbits

    Science.gov (United States)

    Kohler, Susanna

    2017-04-01

    This figure (click for the full view) shows the meridional galactic orbits of 12 globular clusters that orbit the Milky Way. The recent release of stellar parallax data from Gaia allowed a team of scientists at Dartmouth College to improve measurements of a number of galactic globular clusters very old clusters of stars that can either orbit within the galactic disk and bulge or more distantly in the galactic halo. In a recent publication led by Erin OMalley, the team presents their findings and combines their new measurements for the clusters with proper motions from past studies to calculate the orbits that these globulars take. These calculations show us whether the clusters reside in the galactic disk and bulge (as only NGC 104 does in the sample shown here, since its orbit is confined to 8 kpc radially and 4 kpc vertically of the galactic center), or if they are halo clusters. To learn more about the authors work, you can check out the paper below!CitationErin M. OMalley et al 2017 ApJ 838 162. doi:10.3847/1538-4357/aa6574

  9. Orbital positioning and stationkeeping of geostationary satellites

    Science.gov (United States)

    Donat, H.

    Orbit, launcher, and satellite related constraints on launch windows are reviewed. The flight sequence and orbital position optimization of spin and three axis stabilized satellites are described. Geostationary orbit perturbations and evolution, and orbit correction are considered. North-south and east-west stationkeeping strategies are outlined. Stationkeeping of Telecom-1 and TDF-1 is illustrated.

  10. ORBITAL CELLULITIS COMPLICATING SINUSITIS: A 15-YEAR ...

    African Journals Online (AJOL)

    Dr. NWaorgu

    Abstract. Background: Orbital cellulitis is an infection of the orbital soft tissues behind the orbital septum. Primary sinus infection is the most common cause of orbital cellulites. It is an ocular emergency that threatens not only vision but also life from complications such as meningitis, cavernous sinus thrombosis, and brain ...

  11. Understanding Pediatric Bacterial Preseptal and Orbital Cellulitis

    OpenAIRE

    Gonzalez, Mithra O.; Durairaj, Vikram D.

    2010-01-01

    Pediatric preseptal and orbital cellulitis are infectious disorders that result in periorbital inflammation. Preseptal cellulitis is often associated with breaches in the skin barrier whereas orbital cellulitis is commonly associated with paranasal sinusitis. Orbital cellulitis may be associated with subperiosteal abscess. It is important to distinguish between preseptal from orbital cellulitis. Clinical examination and diagnostic imaging are useful in determining appropriate management. Pati...

  12. The Eccentric Behavior of Nearly Frozen Orbits

    Science.gov (United States)

    Sweetser, Theodore H.; Vincent, Mark A.

    2013-01-01

    Frozen orbits are orbits which have only short-period changes in their mean eccentricity and argument of periapse, so that they basically keep a fixed orientation within their plane of motion. Nearly frozen orbits are those whose eccentricity and argument of periapse have values close to those of a frozen orbit. We call them "nearly" frozen because their eccentricity vector (a vector whose polar coordinates are eccentricity and argument of periapse) will stay within a bounded distance from the frozen orbit eccentricity vector, circulating around it over time. For highly inclined orbits around the Earth, this distance is effectively constant over time. Furthermore, frozen orbit eccentricity values are low enough that these orbits are essentially eccentric (i.e., off center) circles, so that nearly frozen orbits around Earth are bounded above and below by frozen orbits.

  13. Relative Orbit Elements for Satellites in Elliptical Orbits

    Science.gov (United States)

    2010-03-01

    flying missions [9, 35, 63, 75, 95, 107, 111], such as the European PRISMA mission [22], NASA’s Magnetosphere Multiscale mission [21, 34, 62, 80, 109...Magnetosphere Multiscale (MMS) Mission, 1999. [22] D’Amico, S., Gill, E., and Montenbruck, O., “Relative Orbit Control Design for the PRISMA Formation

  14. Assessing Terra Disposal Orbit Candidates from an Orbital Debris Perspective

    Science.gov (United States)

    Abraham, Andrew J.; Thompson, Roger C.; Mantziaras, Dimitrios C.

    2016-01-01

    The NASA Terra satellite is reaching the end of its mission life. Because the satellite resides in the 705 km Earth Science Constellation, disposal strategies need to be considered to remove it from this densely populated operational orbit. Of critical importance was the need to examine the future potential risk to other satellite residents of the 705 km constellation due to an unexpected breakup event of the Terra satellite post-disposal. This study quantifies the comparative risk of debris impacts associated with the two leading candidate disposal orbits (701 km vs. 686 km) and characterizes the suitability of each orbit for the purpose of long-term spacecraft disposal. The increase in collision risk to any member of the 705 km Earth Science Constellation is very modest. The long-term, average, total risk (including the ambient background risk) due to a Terra breakup at a disposal of -19 km (i.e., 686 km) relative to the 705 km constellation is 9.7 × 10(exp -6) impacts/day versus 1.0 × 10(exp -5) impacts/day for a disposal of only -4 km (i.e., 701 km). For perspective, note that the nominal space background risk to the 705 km constellation is 9.2 × 10(exp -6) impacts/day which implies a very modest increase in risk (approximately 3% difference between the two cases) due to a Terra breakup in either disposal orbit.

  15. AA, closed orbit observation pickup

    CERN Multimedia

    1980-01-01

    Electrostatic pickups around the circumference of the AA served for the measurement of the closed orbits across the wide momentum range of +- 3% to either side of central orbit. The pickups were of the "shoebox" type, with diagonal cuts, a horizontal and a vertical one mechanically coupled together. They were located where they would not require extra space. The small ones, like the one we see here, were inserted into the vacuum chamber of the BLG (long and narrow) bending magnets. See also 8001372, 8010042, 8010045

  16. AA, closed orbit observation pickup

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    Electrostatic pickups around the circumference of the AA served for the measurement of the closed orbits across the wide momentum range of +- 3% to either side of central orbit. The pickups were of the "shoebox" type, with diagonal cuts, a horizontal and a vertical one mechanically coupled together. They were located where they would not require extra space. The wide ones (very wide indeed: 70 cm), like the one we see here, were placed inside the vacuum chamber of the wide quadrupoles QFW, at maximum dispersion. See also 8001372, 8001383, 8010045

  17. AA, closed orbit observation pickup

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    Electrostatic pickups around the circumference of the AA served for the measurement of the closed orbits across the wide momentum range of +- 3% to either side of central orbit. The pickups were of the "shoebox" type, with diagonal cuts, a horizontal and a vertical one mechanically coupled together. They were located where they would not require extra space. The small ones, like the one we see here, were inserted into the vacuum chamber of the BLG (long and narrow) bending magnets. Werner Sax contemplates his achievement. See also 8001383, 8010042, 8010045.

  18. AA, closed orbit observation pickup

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    Electrostatic pickups around the circumference of the AA served for the measurement of the closed orbits across the wide momentum range of +- 3% to either side of central orbit. The pickups were of the "shoebox" type, with diagonal cuts, a horizontal and a vertical one mechanically coupled together. They were located where they would not require extra space. The wide ones (very wide indeed: 70 cm), like the one we see here, were placed inside the vacuum chamber of the wide quadrupoles, QFW, at maximum dispersion. See also 8001372,8001383, 8010042

  19. Orbital resonances around black holes.

    Science.gov (United States)

    Brink, Jeandrew; Geyer, Marisa; Hinderer, Tanja

    2015-02-27

    We compute the length and time scales associated with resonant orbits around Kerr black holes for all orbital and spin parameters. Resonance-induced effects are potentially observable when the Event Horizon Telescope resolves the inner structure of Sgr A*, when space-based gravitational wave detectors record phase shifts in the waveform during the resonant passage of a compact object spiraling into the black hole, or in the frequencies of quasiperiodic oscillations for accreting black holes. The onset of geodesic chaos for non-Kerr spacetimes should occur at the resonance locations quantified here.

  20. Orbital-only models: ordering and excitations

    Science.gov (United States)

    van den Brink, Jeroen

    2004-12-01

    We consider orbital-only models in Mott insulators, where the orbital orbital interactions are either due to Jahn Teller distortions or due to the Kugel Khomskii superexchange. This leads to highly anisotropic and frustrated orbital Hamiltonians. For two-fold degenerate eg systems, both types of orbital interactions lead to the same form of the Hamiltonian—the 120° model. In both cases, the predicted symmetry of the orbital ordering is the same, although different from the one observed experimentally. The orbital operators that appear in the two kinds of orbital-only Hamiltonians are different. In the case of superexchange, the orbital degrees of freedom are represented by quantum pseudo-spin 1/2 operators. But when the interactions are Jahn Teller mediated and the coupling with the lattice is strong, the orbital operators are essentially classical pseudospins. Thus as a function of the relative coupling strengths, a quantum-to-classical crossover is expected. For three-fold degenerate t2g orbitals, the Jahn Teller coupling gives rise to a particular type of orbital compass models. We point out that fluctuations—whether due to quantum effects or finite temperature—are of prime importance for ordering in the 120° and orbital compass models. The fluctuations generally generate a gap in the orbital excitation spectrum. These orbital excitations—orbitons—are hybrid excitations that carry both a lattice Jahn Teller and a magnetic Kugel Khomskii character.

  1. A rare case of orbital granulomatous inflammation from explosive hydraulic oil masquerading as orbital cellulitis.

    Science.gov (United States)

    Cheema, Marvi; Roelofs, Kelsey; Jivraj, Imran; West, Robert; Rasmussen, Steve; Chan, Audrey

    2017-10-20

    The differential diagnosis for acute orbital inflammation is broad. We report a case of granulomatous orbital inflammation due to high-pressure oil injury to the orbit presenting as an atypical orbital cellulitis. Here we review the presentation and treatment of orbital inflammation from oil.

  2. Petrological and geochemical constraints on the origin of mafic dykes intruding the composite Kaçkar Pluton from the eastern Blacksea magmatic arc, NE Turkey

    Science.gov (United States)

    Aydin, Faruk; Oguz, Simge; Baser, Rasim; Uysal, Ibrahim; Sen, Cüneyt; Karsli, Orhan; Kandemir, Raif

    2015-04-01

    Geological, petrographical and geochemical data of mafic dykes intruding the composite Kaçkar Pluton from the eastern Blacksea magmatic arc (EBMA), NE Turkey, provide new insights into the nature of the metasomatizing agents in subcontinental lithospheric mantle beneath the region during the late Mesozoic-early Tertiary. Mafic dykes from the Çaykara and Hayrat (Trabzon), and also Ikizdere (Rize) areas from the northern margin of the EBMA consist of basalts, dolerites, lamprophyres (basic member) and lesser basaltic andesites and trachyandesites (evolved member). All dykes have no deformation and metamorphism. The outcrops of these dykes vary, with thickness from 0.2 to 10 m. and visible length from 3 to 20 m. In general, the mafic dykes dip steeply and cut directly across the Kaçkar Pluton, and show NW- and NE-trending, roughly parallel to the orientations of the EBMA main faults. Most of the dyke samples display subaphyric to porphyritic texture with phenocrysts of plagioclase (up to 10%), clinopyroxene (5-20%), amphibole (5-15%), and some contain variable amount of biotite (5-20%), lesser quartz (1-2%), and minor euhedral zircon, apatite and Fe-Ti oxides. The basic members of the mafic dykes have SiO2 of 44.1-51.9%, MgO of 4.5-12.1%, and TiO2 >mostly 0.8% (up to 2.3%) with K2O+Na2O of 1.3-6.6% with mostly subalkaline character. They are relatively high in mg-number (0.45-0.73) and transition metals (V=171-376 ppm, Co=22-45 ppm, Ni=3-148 ppm, and Sc=21-49 ppm). The evolved members of the dykes exhibit relatively higher SiO2 (57.1-60.2%) and K2O+Na2O (5.6-9.0%), and lower MgO (2.2-5.9%) and TiO2 (0.5-0.8%) contents than those from the basic dykes. Also, these samples have slightly low mg-number (0.41-0.65) and transition metals (V=99-172 ppm, Co=9-22 ppm, Ni=1-43 ppm, and Sc=9-20 ppm). In the Harker diagrams, all samples of the mafic dykes form a continuous array, and exhibit similar geochemical characteristics. In general, SiO2 inversely correlates with MgO, Fe

  3. Orbitally excited charm - strange mesons

    Energy Technology Data Exchange (ETDEWEB)

    Kasper, Penelope A. [Illinois Inst. of Technology, Chicago, IL (United States)

    1996-05-01

    This thesis describes an attempt to measure the properties of mesons containing a charm quark and a strange quark in a state of orbital angular momentum L > 0, and compare these with the predictions of theoretical models based on heavy quark effective theory.

  4. THREE PLANETS ORBITING WOLF 1061

    Energy Technology Data Exchange (ETDEWEB)

    Wright, D. J.; Wittenmyer, R. A.; Tinney, C. G.; Bentley, J. S.; Zhao, Jinglin, E-mail: duncan.wright@unsw.edu.au [Department of Astronomy and Australian Centre for Astrobiology, School of Physics, University of New South Wales, NSW 2052 (Australia)

    2016-02-01

    We use archival HARPS spectra to detect three planets orbiting the M3 dwarf Wolf 1061 (GJ 628). We detect a 1.36 M{sub ⊕} minimum-mass planet with an orbital period P = 4.888 days (Wolf 1061b), a 4.25 M{sub ⊕} minimum-mass planet with orbital period P = 17.867 days (Wolf 1061c), and a likely 5.21 M{sub ⊕} minimum-mass planet with orbital period P = 67.274 days (Wolf 1061d). All of the planets are of sufficiently low mass that they may be rocky in nature. The 17.867 day planet falls within the habitable zone for Wolf 1061 and the 67.274 day planet falls just outside the outer boundary of the habitable zone. There are no signs of activity observed in the bisector spans, cross-correlation FWHMs, calcium H and K indices, NaD indices, or Hα indices near the planetary periods. We use custom methods to generate a cross-correlation template tailored to the star. The resulting velocities do not suffer the strong annual variation observed in the HARPS DRS velocities. This differential technique should deliver better exploitation of the archival HARPS data for the detection of planets at extremely low amplitudes.

  5. CONGENITAI, ORBITAL, TERATOMIA IN A

    African Journals Online (AJOL)

    calcification encasing a deformed globe (computerized axial tomography scan). A lid-sparing modified exenteration with temporalis muscle transplant/split skin graft was performed. Histopathology reports on biopsy tissues revealed derivatives of all three germ cell layers consistent with the diagnosis of orbital teratoma.

  6. Getting a Crew into Orbit

    Science.gov (United States)

    Riddle, Bob

    2011-01-01

    Despite the temporary setback in our country's crewed space exploration program, there will continue to be missions requiring crews to orbit Earth and beyond. Under the NASA Authorization Act of 2010, NASA should have its own heavy launch rocket and crew vehicle developed by 2016. Private companies will continue to explore space, as well. At the…

  7. Optimal Reorientation Of Spacecraft Orbit

    Directory of Open Access Journals (Sweden)

    Chelnokov Yuriy Nikolaevich

    2014-06-01

    Full Text Available The problem of optimal reorientation of the spacecraft orbit is considered. For solving the problem we used quaternion equations of motion written in rotating coordinate system. The use of quaternion variables makes this consideration more efficient. The problem of optimal control is solved on the basis of the maximum principle. An example of numerical solution of the problem is given.

  8. Orbital abscess: Management and outcome

    Directory of Open Access Journals (Sweden)

    N Suneetha

    2000-01-01

    Full Text Available Purpose: To discuss the diagnosis, management and outcome of various types of orbital abscess. Methods: The medical records of 13 patients diagnosed and treated for orbital abscess were reviewed. The sources of infection included: paranasal sinusitis (n = 5, odontogenic origin of infection (n = 4, one each, temporal fossa abscess, palatal abscess, furuncle on the nose, and secondary to retrobulbar injection of steroid. Computed tomographic scans revealed the presence of an abscess in all 13 cases. Associated findings on CT scan included: sinus disease (n = 8, cavernous sinus thrombosis (n = 2 and subdural empyema (n = 2. All patients were treated with intensive, multiple, intravenous antibiotics and early surgical drainage. Results: Purulent material collected surgically from the orbit cultured Staphylococcus aureus (n = 3, two each Pseudomonas aeruginosa, Proteus mirabilis, Acinetobacter species and one each β-haemolytic Streptococci, Citrobacter frundi and Enterobacter. Final visual acuity was good in 6 patients (6/12 - 6/6 and no light perception in 6 others. Visual acuity could not be recorded in the infant. The other complications were intracranial abscess (n = 4, cavernous sinus thrombosis (n = 2 and restricted ocular motility (n = 1. Conclusions: A high index of suspicion is necessary, along with early institution of appropriate diagnostic imaging, and aggressive medical and surgical treatment for a favourable outcome in cases of orbital abscess.

  9. Retinoblastoma presenting with orbital cellulitis.

    Science.gov (United States)

    Walinjkar, Jaydeep; Krishnakumar, S; Gopal, Lingam; Ramesh, Anita; Khetan, Vikas

    2013-06-01

    To study the effectiveness of pre-enucleation steroids in reducing inflammation in patients with retinoblastoma presenting as orbital cellulitis. Medical records of consecutive retinoblastoma patients presenting at a single tertiary eye care center during a period of 3 years were retrospectively reviewed. For those who presented with orbital cellulitis, clinical, radiological, and histopathological variables were assessed. The effect of pre-enucleation steroids was noted in this group of patients. Of 260 retinoblastoma cases reviewed, 14 had retinoblastoma-associated cellulitis (5.39%). Of these 14 patients, 4 received neoadjuvant chemotherapy and were excluded from the series. Of the remaining 10 cases (mean age at presentation, 14.2 months; mean follow-up, 16.4 months), 9 presented with orbital cellulitis and were included in the study. Radiological imaging depicted intraocular tumors occupying 80% to 100% of the globe in each case. All patients underwent enucleation. Five children received pre-enucleation systemic steroids (mean, 5.4 days), which resulted in a prompt decrease in inflammation. Postenucleation chemotherapy was administered in 4 (6 cycles) and external beam radiation therapy in 1 patient with high-risk histopathological characteristics. Advanced necrotic retinoblastoma with anterior segment involvement may present as orbital cellulitis. Pre-enucleation systemic steroids can aid in the surgical management of these tumors. Copyright © 2013 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

  10. DOT strategies versus orbiter strategies

    NARCIS (Netherlands)

    Rutten, R.J.

    2001-01-01

    The Dutch Open Telescope is a high-resolution solar imager coming on-line at La Palma. The definition of the DOT science niche, strategies, and requirements resemble Solar Orbiter considerations and deliberations. I discuss the latter in the light of the former, and claim that multi-line observation

  11. The Coupled Orbit-Attitude Dynamics and Control of Electric Sail in Displaced Solar Orbits

    National Research Council Canada - National Science Library

    Mingying Huo; He Liao; Yanfang Liu; Naiming Qi

    2017-01-01

    .... The results of stability analysis show that only some of the orbits are marginally stable. For unstable displaced orbits, linear quadratic regulator is employed to control the coupled attitude-orbit...

  12. [Orbital mycetoma: a case report].

    Science.gov (United States)

    Gueye, N N; Seck, S M; Diop, Y; Ndiaye Sow, M N; Agboton, G; Diakhaté, M; Dieng, M; Dieng, M T

    2013-05-01

    Mycetomas are pathological processes through which exogenous fungal or actinomycotic etiological agents produce grains. These etiological agents live in the soil and plants of endemic areas. They are introduced traumatically, primarily into the foot. The orbital location is rare. We report the case of a 17-year-old student admitted for progressive left proptosis over 2 years, following penetrating trauma by a fork in a rural setting. Examination revealed a heterogenous orbital mass with multiple fistulae, producing pus and black grains, and suggested, due to the color of the grains, a diagnosis of fungal mycetoma. MRI revealed a destructive process at the level of the lamina papracea of the ethmoid and the orbital floor. Anatomopathological examination confirmed the fungal nature of the infection, while culture in Sabouraud's medium was inconclusive. The outcome was favorable after exenteration and debridementof the ipsilateral maxillary sinus and nasal cavities, along with 4 months of ketoconazole. No recurrence has been observed for 14 months after surgery. Mycetomas are endemic to northwest Africa. Most frequently located in the foot, they are seldom seen in the orbit. The color of the grains provides a clue as to the etiology. Black-grain mycetomas are always fungal and are treated surgically--essentially like cancer--as the persistence of a single grain will cause a recurrence. The orbital location of a mycetoma is rare. In the present case report, the concept of port of entry, the clinical appearance, and the color of the grains guided the diagnosis. The histological examination of the surgical specimen confirmed the diagnosis. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  13. Space Shuttle Orbiter-Illustration

    Science.gov (United States)

    2001-01-01

    This illustration is an orbiter cutaway view with callouts. The orbiter is both the brains and heart of the Space Transportation System (STS). About the same size and weight as a DC-9 aircraft, the orbiter contains the pressurized crew compartment (which can normally carry up to seven crew members), the huge cargo bay, and the three main engines mounted on its aft end. There are three levels to the crew cabin. Uppermost is the flight deck where the commander and the pilot control the mission. The middeck is where the gallery, toilet, sleep stations, and storage and experiment lockers are found for the basic needs of weightless daily living. Also located in the middeck is the airlock hatch into the cargo bay and space beyond. It is through this hatch and airlock that astronauts go to don their spacesuits and marned maneuvering units in preparation for extravehicular activities, more popularly known as spacewalks. The Space Shuttle's cargo bay is adaptable to hundreds of tasks. Large enough to accommodate a tour bus (60 x 15 feet or 18.3 x 4.6 meters), the cargo bay carries satellites, spacecraft, and spacelab scientific laboratories to and from Earth orbit. It is also a work station for astronauts to repair satellites, a foundation from which to erect space structures, and a hold for retrieved satellites to be returned to Earth. Thermal tile insulation and blankets (also known as the thermal protection system or TPS) cover the underbelly, bottom of the wings, and other heat-bearing surfaces of the orbiter to protect it during its fiery reentry into the Earth's atmosphere. The Shuttle's 24,000 individual tiles are made primarily of pure-sand silicate fibers, mixed with a ceramic binder. The solid rocket boosters (SRB's) are designed as an in-house Marshall Space Flight Center project, with United Space Boosters as the assembly and refurbishment contractor. The solid rocket motor (SRM) is provided by the Morton Thiokol Corporation.

  14. Solitary extramedullary plasmacytoma of the maxillary antrum and orbit presenting as acute bacterial orbital cellulitis.

    Science.gov (United States)

    Kelly, S. P.; Lloyd, I. C.; Anderson, H.; Joyce, P. W.; Pace-Balzan, A.

    1991-01-01

    Orbital involvement by plasma cell tumours is rare. Orbital tumours do not generally present as an acute orbital inflammatory disease in adults, though tumours such as rhabdomyosarcoma may cause clinical signs similar to an acute orbital cellulitis in children. We describe a patient with bacterial orbital cellulitis and sinusitis who was found to have an extra-medullary plasmacytoma of the maxillary antrum and orbit and coexisting testicular seminoma. Images PMID:1854702

  15. Precision Analysis of LEO Satellite Orbit Prediction

    Directory of Open Access Journals (Sweden)

    WANG Yafei

    2016-09-01

    Full Text Available The accuracy of different fitting intervals on the predicted orbit of different arc lengths was analyzed by using the dynamic fitting method and taken HY-2A satellite as an example. According to two orbit products, one was the precise orbit obtained by CNES and the other was rapid orbit computed by adopting zero-different reduced dynamic method, obtaining the precise predicted orbit. By the results, we can get that the 3DRMS is near 6dm by using 12h or 24h fitting orbit to forecast 12h arc; the 3DRMS is near 1m when forecasting 24h arc.

  16. Aiming at a 1-cm orbit for low earth orbiters : Reduced-dynamic and kinematic precise orbit determination

    NARCIS (Netherlands)

    Visser, P.N.A.M.; Van den IJssel, J.

    2003-01-01

    The computation of high-accuracy orbits is a prerequisite for the success of Low Earth Orbiter (LEO) missions such as CHAMP, GRACE and GOCE. The mission objectives of these satellites cannot be reached without computing orbits with an accuracy at the few cm level. Such a level of accuracy might be

  17. 'Agony aunt, hostage, intruder or friend?'. The multiple personas of the interviewer during fieldwork 'Agony aunt, hostage, intruder or friend?'. The multiple personas of the interviewer during fieldwork ¿Consultor sentimental, intruso, rehén o amigo? Los múltiples papeles del entrevistador durante el trabajo de campo

    Directory of Open Access Journals (Sweden)

    Valerie Caven

    2012-12-01

    Full Text Available Purpose: This paper examines how the role of the intervieweris manipulated by the interviewees in return for them offering their experiences, opinions and information during qualitative research interviews.Design/methodology: Semi-structured interviews in the qualitative paradigm were carried out with 55 architects from the East Midlands region of the UK. The interview data is supported by research diary evidence.Findings: A typology of four interviewer personas is presented: as ‘agony aunt, hostage, intruder or friend’.Research limitations/implications: The four personas were generated by the interviewees’ responses to one researcher which is a limitation. However, the study could be replicated with other researchers/interviewers in different interview situations.Practical implications: The research has practical value in highlighting the multiple facets of the relationship between interviewer and interviewee in qualitative research. It will be of value to both experienced and new researchers.Originality/value: The development of the typology represents the originality and value of the research. Previous research has focused more on telling the stories rather than the development of new theory relating to interviewing.Purpose: This paper examines how the role of the interviewer is manipulated by the interviewees in return for them offering their experiences, opinions and information during qualitative research interviews. Design/methodology: Semi-structured interviews in the qualitative paradigm were carried out with 55 architects from the East Midlands region of the UK. The interview data is supported by research diary evidence. Findings: A typology of four interviewer personas is presented: as ‘agony aunt, hostage, intruder or friend’. Research limitations/implications: The four personas were generated by the interviewees’ responses to one researcher which is a limitation. However, the study could be replicated with other

  18. Robustness analysis method for orbit control

    Science.gov (United States)

    Zhang, Jingrui; Yang, Keying; Qi, Rui; Zhao, Shuge; Li, Yanyan

    2017-08-01

    Satellite orbits require periodical maintenance due to the presence of perturbations. However, random errors caused by inaccurate orbit determination and thrust implementation may lead to failure of the orbit control strategy. Therefore, it is necessary to analyze the robustness of the orbit control methods. Feasible strategies which are tolerant to errors of a certain magnitude can be developed to perform reliable orbit control for the satellite. In this paper, first, the orbital dynamic model is formulated by Gauss' form of the planetary equation using the mean orbit elements; the atmospheric drag and the Earth's non-spherical perturbations are taken into consideration in this model. Second, an impulsive control strategy employing the differential correction algorithm is developed to maintain the satellite trajectory parameters in given ranges. Finally, the robustness of the impulsive control method is analyzed through Monte Carlo simulations while taking orbit determination error and thrust error into account.

  19. Assessment and management of orbital cellulitis.

    Science.gov (United States)

    Amin, Nikul; Syed, Irfan; Osborne, Sarah

    2016-04-01

    Orbital cellulitis is a medical emergency requiring multidisciplinary team involvement. Early diagnosis and intervention is imperative to avoid serious complications. This article provides an evidence-based approach to the assessment and management of patients with orbital cellulitis.

  20. MOOSE: Manned On-Orbit Servicing Equipment

    Science.gov (United States)

    Budinoff, J.; Leontsinis, N.; Lane, J.; Singh, R.; Angelone, K.; Boswell, C.; Chamberlain, I.; Concha, M.; Corrodo, M.; Custodio, O.

    The ability to service satellites has thus far been limited to low earth orbit platforms within reach of the Space Shuttle. Other orbits, such as geosynchronous orbits containing high-value spacecraft have not been attainable by a servicing vehicle. The useful life of a satellite can be extended by replacing spent propellant and damaged orbital replacement units, forestalling the need for eventual replacement. This growing need for satellite on-orbits servicing can be met by the Manned On-Orbit Servicing Equipment (MOOSE). Missions requiring orbit transfer capability, precision manipulation and maneuvering, and man-in-the-loop control can be accomplished using MOOSE. MOOSE is a flexible, reusable, single operator, aerobraking spacecraft designed to refuel, repair, and service orbiting spacecraft. MOOSE will be deployed from Space Station Freedom, (SSF), where it will be stored, resupplied, and refurbished.

  1. SILEX in-orbit performances

    Science.gov (United States)

    Planche, Gilles; Chorvalli, Vincent

    2004-06-01

    PASTEL embarked on-board SPOT4, French LEO earth observation satellite, and OPALE mounted on-board ARTEMIS, European GEO telecommunication satellite are the key components of SILEX (Semi-conductor Inter-satellite Link Experiment) system. Launched in March 1998, PASTEL terminal was first verified via star tracking. Then, first SILEX optical communication was successfully performed in December 2001 with ARTEMIS at 31000 km. Following 12 months ARTEMIS orbit rising, SILEX commissioning phase was successfully achieved in spring 2003. Today, more than hundred successful optical communications have been achieved. On 1st of October 2003, the SILEX optical link was declared fully operational by the European and French space agencies. After a recall of SILEX architecture, design and on-ground verification, this paper reports on in-orbit results.

  2. Has Nemesis' orbit been detected?

    Science.gov (United States)

    Delsemme, A. H.

    1986-01-01

    The orbital angular momenta of 126 very young comets are calculated from the orbital data of Marsden and Roemer (1982) and analyzed statistically. A large anisotropy is detected in a plane almost perpendicular to the ecliptic and shown to have a characteristic dissipation lifetime of 10-30 Myr. Dynamic evolution computations indicate that the impulse which produced the anisotropy is that of a very slow massive (10-90 Jupiter mass) body, which is bound to the solar system, passed its 15,000-35,000-AU perihelion about 2-15 Myr ago, and has period 5-50 Myr. It is suggested that this body could well be identical to Nemesis, the object proposed to explain mass faunal extinctions.

  3. The Orbiting Primate Experiment (OPE)

    Science.gov (United States)

    Bourne, G. H.; Debourne, M. N. G.; Mcclure, H. M.

    1977-01-01

    Instrumentation and life support systems are described for an experiment to determine the physiological effects of long term space flight on unrestrained, minimally instrumented rhesus macaques flown in orbit for periods up to six months or one year. On return from orbit, vestibular, cardiovascular, and skeletal muscle function will be tested. Blood chemistry and hematological studies will be conducted as well as tests of the immunological competence of selected animals. Nasal, rectal, and throat swabs will be used for bacterial and viral studies, and histopathological and histochemical investigations will be be made of all organs using light and electron microscopy. The experiment is being considered as a payload for the biomedical experiment scientific satellite.

  4. Canadian Meteor Orbit Radar (CMOR

    Directory of Open Access Journals (Sweden)

    A. R. Webster

    2004-01-01

    Full Text Available The radar system described here (CMOR comprises a basic 5-element receiving system, co-located with a pulsed transmitter, specifically designed to observe meteor echoes and to determine their position in space with an angular resolution of ~1° and a radial resolution of ~3 km. Two secondary receiving sites, a few km distant and arranged to form approximately a right angle with the base station, allow the determination of the velocity (speed and direction of the meteor that, together with the time of occurrence, lead to an estimate of the orbit of the original meteoroid. Some equipment details are presented along with a method used to determine the orbits. Representative echoes are shown and observations on the 2002 Leonid shower presented.

  5. Gauge Freedom in Orbital Mechanics

    OpenAIRE

    Efroimsky, Michael

    2006-01-01

    In orbital and attitude dynamics the coordinates and the Euler angles are expressed as functions of the time and six constants called elements. Under disturbance, the constants are endowed with time dependence. The Lagrange constraint is then imposed to guarantee that the functional dependence of the perturbed velocity on the time and constants stays the same as in the undisturbed case. Constants obeying this condition are called osculating elements. The constants chosen to be canonical are c...

  6. GridOrbit public display

    DEFF Research Database (Denmark)

    Ramos, Juan David Hincapie; Tabard, Aurélien; Bardram, Jakob

    2010-01-01

    the research taking place in the biology laboratory. This should promote contribu-tions to the grid, and thereby mediate the appropriation of the grid technology. GridOrbit visualizes the activity in the grid, shows information about the different active projects, and supports a messaging functionality where...... people comment on projects. Our work explores the usage of interactive technologies as enablers for the appropriation of an otherwise invisible infrastructure....

  7. Orbital assembly and maintenance study

    Science.gov (United States)

    Gorman, D.; Grant, C.; Kyrias, G.; Lord, C.; Rombach, J.; Salis, M.; Skidmore, R.; Thomas, R.

    1975-01-01

    The requirements, conceptual design, tradeoffs, procedures, and techniques for orbital assembly of the support structure of the microwave power transmission system and the radio astronomy telescope are described. Thermal and stress analyses, packaging, alignment, and subsystems requirements are included along with manned vs. automated and transportation tradeoffs. Technical and operational concepts for the manned and automated maintenance of satellites were investigated and further developed results are presented.

  8. Understanding Pediatric Bacterial Preseptal and Orbital Cellulitis

    Science.gov (United States)

    Gonzalez, Mithra O.; Durairaj, Vikram D.

    2010-01-01

    Pediatric preseptal and orbital cellulitis are infectious disorders that result in periorbital inflammation. Preseptal cellulitis is often associated with breaches in the skin barrier whereas orbital cellulitis is commonly associated with paranasal sinusitis. Orbital cellulitis may be associated with subperiosteal abscess. It is important to distinguish between preseptal from orbital cellulitis. Clinical examination and diagnostic imaging are useful in determining appropriate management. Patients are usually treated with broad spectrum antibiotics and surgery when indicated. PMID:20616919

  9. A new kinematical definition of orbital eccentricity

    Directory of Open Access Journals (Sweden)

    Ninković S.

    2009-01-01

    Full Text Available A new concept of orbital eccentricity is given. The dimensionless quantities proposed in the present paper to serve as orbital eccentricities have a kinematical nature. The purpose is to use them in describing the motion for the case of three-dimensional orbits. A comparison done for nearly planar orbits shows that the values of the eccentricities proposed here do not differ significantly from those corresponding to the eccentricities of geometric nature usually applied.

  10. Extended Duration Orbiter Medical Project

    Science.gov (United States)

    Leach, C. S.; Pool, S. L.; Sawin, C. F.; Nicogossian, A. E.

    1990-01-01

    The Extended Duration Orbiter (EDO) program addresses a need for more time to perform experiments and other tasks during Space Shuttle missions. As a part of this program, the Extended Duration Orbiter Medical Project (EDOMP) has been instituted to obtain information about physiologic effects of extending mission duration and the effectiveness of countermeasures against factors that might compromise crew health, safety, or performance on extended-duration missions. Only those investigations that address and characterize operational problems, develop countermeasures, or evaluate the effectiveness of countermeasures will be pursued. The EDOMP investigations will include flight-associated Detailed Supplementary Objectives as well as ground-based studies simulating the influence of microgravity. Investigator teams have been formed in the following areas: biomedical physiology, cardiovascular and fluid/electrolyte physiology, environmental health, muscle and exercise physiology, and neurophysiology. Major operational questions must be answered in each of these areas, and investigations have been designed to answer them. The EDO program will proceed only after countermeasures have been shown to be effective in preventing or mitigating the adverse changes they have been designed to attenuate. The program is underway and will continue on each Shuttle flight as the manifest builds toward a 16-day orbital flight.

  11. Molecular Orbitals and the Atomistics of Fracture.

    Science.gov (United States)

    1982-02-10

    dominantly a N-N bonding orbital the N-Fe interaction is non- bonding. The b2 orbital in the Fe4 cluster is d-d w-bonding between nearest neig ;hbo and...distance. This is the distance which is realized when there is no electron density in a N-3 antibonding orbital. In this cluster son of the electron

  12. Classification of Stellar Orbits Near Corotation

    Science.gov (United States)

    Breet, Jessica; Daniel, Kathryne J.; Bryn Mawr College Galaxy Lab

    2018-01-01

    The process of radial migration is frequently invoked as an important process to spiral galaxy evolution, but the physical properties that determine the efficiency of radial migration are poorly defined. In order for a star to migrate radially it must first be trapped in a resonant orbit at the corotation radius of a spiral pattern. Stars in such trapped orbits have changing average orbital radii — and thus orbital angular momenta — without any change in orbital eccentricity. It follows that transient spiral patterns can permanently rearrange the distribution of orbital angular momentum in the disk without kinematically heating it. It is also known that orbits can also have a significant dynamical response at Lindblad Resonances (LRs), where the Ultraharmonic Lindblad Resonances (ULRs) have a lesser impact on the disk. The goal of our project is to examine and constrain the efficiency of radial migration via an investigation into whether or not stars in trapped orbits have a dynamical response at the ULRs. We produced a dataset of nearly 105 orbits with initial conditions across a range of radii and 2-D velocities. We then classified these orbits into four categories based on analytic criteria for whether or not they are in trapped orbits and/or cross the ULR over 1 gigayear. Preliminary investigations show that trapped orbits that also meet the ULR have a chaotic response, putting a potential limit on the efficiency of radial migration.

  13. Periodic Orbits and Deformed Shell Structure

    OpenAIRE

    Arita, K.; Magner, A. G.; Matsuyanagi, K.

    2002-01-01

    Relationship between quantum shell structure and classical periodic orbits is briefly reviewed on the basis of semi-classical trace formula. Using the spheroidal cavity model, it is shown that three-dimensional periodic orbits, which are born out of bifurcation of planar orbits at large prolate deformations, generate the superdeformed shell structure.

  14. On Directional Measurement Representation in Orbit Determination

    Science.gov (United States)

    2016-09-13

    Precision Orbit Determination (OD) is often critical for successful satellite operations supporting a wide variety of missions. Directional or angles only...representations. The three techniques are then compared experimentally for a geostationary and a low Earth orbit satellite using simulated data to evaluate their... Orbit Determination (OD) is often critical for successful satellite operations supporting a wide variety of missions. Precision OD involves

  15. Cesium's Off-the-Map Valence Orbital

    NARCIS (Netherlands)

    Goesten, Maarten G.; Rahm, Martin; Bickelhaupt, F. Matthias; Hensen, Emiel J.M.

    2017-01-01

    The Td-symmetric [CsO4]+ ion, featuring Cs in an oxidation state of 9, is computed to be a minimum. Cs uses outer core 5s and 5p orbitals to bind the oxygen atoms. The valence Cs 6s orbital lies too high to be involved in bonding, and contributes to Rydberg levels only. From a molecular orbital

  16. The orbital record in stratigraphy

    Science.gov (United States)

    Fischer, Alfred G.

    1992-01-01

    Orbital signals are being discovered in pre-Pleistocene sediments. Due to their hierarchical nature these cycle patterns are complex, and the imprecision of geochronology generally makes the assignment of stratigraphic cycles to specific orbital cycles uncertain, but in sequences such as the limnic Newark Group under study by Olsen and pelagic Cretaceous sequence worked on by our Italo-American group the relative frequencies yield a definitive match to the Milankovitch hierarchy. Due to the multiple ways in which climate impinges on depositional systems, the orbital signals are recorded in a multiplicity of parameters, and affect different sedimentary facies in different ways. In platform carbonates, for example, the chief effect is via sea-level variations (possibly tied to fluctuating ice volume), resulting in cycles of emergence and submergence. In limnic systems it finds its most dramatic expression in alternations of lake and playa conditions. Biogenic pelagic oozes such as chalks and the limestones derived from them display variations in the carbonate supplied by planktonic organisms such as coccolithophores and foraminifera, and also record variations in the aeration of bottom waters. Whereas early studies of stratigraphic cyclicity relied mainly on bedding variations visible in the field, present studies are supplementing these with instrumental scans of geochemical, paleontological, and geophysical parameters which yield quantitative curves amenable to time-series analysis; such analysis is, however, limited by problems of distorted time-scales. My own work has been largely concentrated on pelagic systems. In these, the sensitivity of pelagic organisms to climatic-oceanic changes, combined with the sensitivity of botton life to changes in oxygen availability (commonly much more restricted in the Past than now) has left cyclic patterns related to orbital forcing. These systems are further attractive because (1) they tend to offer depositional continuity

  17. Improved virtual orbitals in state specific multireference perturbation theory for prototypes of quasidegenerate electronic structure

    Science.gov (United States)

    Sinha Ray, Suvonil; Ghosh, Pradipta; Chaudhuri, Rajat K.; Chattopadhyay, Sudip

    2017-02-01

    The state-specific multireference perturbation theory (SSMRPT) with an improved virtual orbital complete active space configuration interaction (IVO-CASCI) reference function [called as IVO-SSMRPT] is used to investigate the energy surface, geometrical parameters, molecular properties of spectroscopic interest for the systems/situations [such as BeH2, BeCH2, MgCH2, Si2H4, unimolecular dissociation of H2CO, and intramolecular reaction pathways of 1,3-butadiene] where the effect of quasidegeneracy cannot be neglected. The merit of using the IVO-CASCI rather than complete active space self-consistent field (CASSCF) is that it is free from iterations beyond those in the initial SCF calculation and the convergence difficulties that plague CASSCF calculations with increasing size of the CAS. While IVO-CASCI describes the non-dynamical correlation, the SSMRPT scheme is a good second-order perturbative approximation to account for the rest of the correlation energy. Our IVO-SSMRPT method is instrumental in avoiding intruder states in an size-extensive manner and allows the revision of the content of wave function in the model space. It can treat model as well as real systems with predictive accuracy, as is evident from the fairly nice accordance between our estimates, and high-level theoretical results. Our estimates also corroborate well with some experimental findings.

  18. Precision orbit raising trajectories. [solar electric propulsion orbital transfer program

    Science.gov (United States)

    Flanagan, P. F.; Horsewood, J. L.; Pines, S.

    1975-01-01

    A precision trajectory program has been developed to serve as a test bed for geocentric orbit raising steering laws. The steering laws to be evaluated have been developed using optimization methods employing averaging techniques. This program provides the capability of testing the steering laws in a precision simulation. The principal system models incorporated in the program are described, including the radiation environment, the solar array model, the thrusters and power processors, the geopotential, and the solar system. Steering and array orientation constraints are discussed, and the impact of these constraints on program design is considered.

  19. Management of preseptal and orbital cellulitis

    Science.gov (United States)

    Lee, Seongmu; Yen, Michael T.

    2010-01-01

    Orbital cellulitis describes an infection involving the soft tissues posterior to the orbital septum, including the fat and muscle within the bony orbit. This condition may be associated with severe sight and life-threatening complications. Despite significant advances in antimicrobial therapies and diagnostic technologies, the management of orbital cellulitis often remains challenging, and rapid diagnosis and prompt initiation of therapy are important in minimizing complications and optimizing outcomes. This review summarizes the distinctive characteristics of preseptal and orbital cellulitis, with a focus on anatomic considerations, predisposing conditions, approaches to evaluation, and management strategies. PMID:23960899

  20. Linear magnetoelectric effect by orbital magnetism.

    Science.gov (United States)

    Scaramucci, A; Bousquet, E; Fechner, M; Mostovoy, M; Spaldin, N A

    2012-11-09

    We use symmetry analysis and first-principles calculations to show that the linear magnetoelectric effect can originate from the response of orbital magnetic moments to the polar distortions induced by an applied electric field. Using LiFePO(4) as a model compound we show that spin-orbit coupling partially lifts the quenching of the 3d orbitals and causes small orbital magnetic moments (μ((L)) ≈ 0.3 μ(B)) parallel to the spins of the Fe(2+) ions. An applied electric field E modifies the size of these orbital magnetic moments inducing a net magnetization linear in E.

  1. [Orbital emphysema: radiologic and ophthalmologic findings].

    Science.gov (United States)

    Solanas-Álava, Susana; Rodríguez-Marco, Nelson Arturo; Artigas-Martín, José María; Fernández-Larripa, Sonia

    2017-01-01

    Orbital emphysema, or the presence of air in orbital tissues, is normally associated with an injury although it can arise when a Valsalva maneuver causes an increase in upper airway pressure. This potential complication of an orbital wall fracture, usually in the ethmoid bone, occurs in 50% of such cases. On fracture, air passes from the nasal fossa, sinuses, or subcutaneous tissue. The condition is benign and transient in most cases, and loss of vision is rare. No protocol for treating orbital emphysema with serious complications in which vision is affected has been established. We report 9 cases of orbital emphysema, describing events leading to the fractures, radiologic findings, and treatments.

  2. Sclerosing Wegener's granulomatosis in the orbit

    DEFF Research Database (Denmark)

    Ostri, Christoffer; Heegaard, Steffen; Prause, Jan Ulrik

    2008-01-01

    PURPOSE: To report three cases of sclerosing Wegener's granulomatosis in the orbit and to compare the histopathological morphology with those of other types of sclerosing orbital inflammation. METHODS: We analysed the clinical data along with histopathological specimens from orbital biopsies......, tissue necrosis, vasculitis and widespread dense fibrosis. In certain areas of all specimens the fibrous tissue was arranged in characteristic concentric, onionskin-like whorls of collagen around obliterated small blood vessels. CONCLUSIONS: Wegener's granulomatosis may lead to orbital fibrosis...... and sclerosis. The stromal changes and cellular infiltrate resemble the non-specific orbital inflammation previously termed orbital pseudotumour. We present the first 'onionskin' lesions in association with Wegener's granulomatosis in the orbit. This latter morphology may represent an abnormal fibrotic reaction...

  3. Mission design of a Pioneer Jupiter Orbiter

    Science.gov (United States)

    Friedman, L. D.; Nunamaker, R. R.

    1975-01-01

    The Mission analysis and design work performed in order to define a Pioneer mission to orbit Jupiter is described. This work arose from the interaction with a science advisory 'Mission Definition' team and led to the present mission concept. Building on the previous Jupiter Orbiter-Satellite Tour development at JPL a magnetospheric survey mission concept is developed. The geometric control of orbits which then provide extensive local time coverage of the Jovian system is analyzed and merged with the various science and program objectives. The result is a 'flower-orbit' mission design, yielding three large apoapse excursions at various local times and many interior orbits whose shape and orientation is under continual modification. This orbit design, together with a first orbit defined by delivery of an atmospheric probe, yields a mission of high scientific interest.

  4. Orbits in weak and strong bars

    CERN Document Server

    Contopoulos, George

    1980-01-01

    The authors study the plane orbits in simple bar models embedded in an axisymmetric background when the bar density is about 1% (weak), 10% (intermediate) or 100% (strong bar) of the axisymmetric density. Most orbits follow the stable periodic orbits. The basic families of periodic orbits are described. In weak bars with two Inner Lindblad Resonances there is a family of stable orbits extending from the center up to the Outer Lindblad Resonance. This family contains the long period orbits near corotation. Other stable families appear between the Inner Lindblad Resonances, outside the Outer Lindblad Resonance, around corotation (short period orbits) and around the center (retrograde). Some families become unstable or disappear in strong bars. A comparison is made with cases having one or no Inner Lindblad Resonance. (12 refs).

  5. Gauge Freedom in Orbital Mechanics

    Science.gov (United States)

    Efroimsky, Michael

    2005-12-01

    In orbital and attitude dynamics the coordinates and the Euler angles are expressed as functions of the time and six constants called elements. Under disturbance, the constants are endowed with time dependence. The Lagrange constraint is then imposed to guarantee that the functional dependence of the perturbed velocity on the time and constants stays the same as in the undisturbed case. Constants obeying this condition are called osculating elements. The constants chosen to be canonical are called Delaunay elements, in the orbital case, or Andoyer elements, in the spin case. (As some Andoyer elements are time dependent even in the free-spin case, the role of constants is played by their initial values.) The Andoyer and Delaunay sets of elements share a feature not readily apparent: in certain cases the standard equations render them non-osculating. In orbital mechanics, elements furnished by the standard planetary equations are non-osculating when perturbations depend on velocities. To preserve osculation, the equations must be amended with extra terms that are not parts of the disturbing function. In the case of Delaunay parameterisation, these terms destroy canonicity. So under velocity-dependent disturbances, osculation and canonicity are incompatible. (Efroimsky and Goldreich 2003, 2004) Similarly, the Andoyer elements turn out to be non-osculating under angular-velocity-dependent perturbation. Amendment of only the Hamiltonian makes the equations render nonosculating elements. To make them osculating, more terms must enter the equations (and the equations will no longer be canonical). In practical calculations, is often convenient to deliberately deviate from osculation by substituting the Lagrange constraint with a condition that gives birth to a family of nonosculating elements.

  6. Kalman Orbit Optimized Loop Tracking

    Science.gov (United States)

    Young, Lawrence E.; Meehan, Thomas K.

    2011-01-01

    Under certain conditions of low signal power and/or high noise, there is insufficient signal to noise ratio (SNR) to close tracking loops with individual signals on orbiting Global Navigation Satellite System (GNSS) receivers. In addition, the processing power available from flight computers is not great enough to implement a conventional ultra-tight coupling tracking loop. This work provides a method to track GNSS signals at very low SNR without the penalty of requiring very high processor throughput to calculate the loop parameters. The Kalman Orbit-Optimized Loop (KOOL) tracking approach constitutes a filter with a dynamic model and using the aggregate of information from all tracked GNSS signals to close the tracking loop for each signal. For applications where there is not a good dynamic model, such as very low orbits where atmospheric drag models may not be adequate to achieve the required accuracy, aiding from an IMU (inertial measurement unit) or other sensor will be added. The KOOL approach is based on research JPL has done to allow signal recovery from weak and scintillating signals observed during the use of GPS signals for limb sounding of the Earth s atmosphere. That approach uses the onboard PVT (position, velocity, time) solution to generate predictions for the range, range rate, and acceleration of the low-SNR signal. The low- SNR signal data are captured by a directed open loop. KOOL builds on the previous open loop tracking by including feedback and observable generation from the weak-signal channels so that the MSR receiver will continue to track and provide PVT, range, and Doppler data, even when all channels have low SNR.

  7. LEIR Closed Orbit Measurement proposal

    CERN Document Server

    Raich, U; CERN. Geneva. AB Department

    2004-01-01

    For the Low Energy Ion Ring (LEIR) continuous (every 10ms) tracking of the closed orbit is necessary during the acceleration and on request. To do so it is foreseen to re-use parts of the existing hardware, mainly the pick-ups (PUs), from LEAR while other parts like the head amplifiers and the acquisition system will have to be re-designed. This note addresses the hardware and software needed for an analogue based acquisition system as well as a DSP based solution. The commissioning of LEIR is foreseen for mid 2005.

  8. Dynamic MRI of orbital lesions

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Akihiro; Matsumoto, Hiroko (Kochi Medical School, Nangoku (Japan))

    1991-04-01

    Study of time intensity curves was performed for 15 orbital lesions. Inflammatory lesions (2 chronic dacryoadenitis, 1 chalazion, 1 inflammatory pseudotumor), 1 meningioma, and 4 pseudolymphoma showed rapid increase with run off. They showed peak formations within 2 minutes. Tumors except for meningioma (3 malignant lymphoma, 2 retinoblastoma, 1 pleomorphic adenoma of lacrimal gland) showed gradual increase without peak formation. No difference between benign and malignancy was detected. Dynamic MRI would be useful for differential diagnosis between pseudotumor and malignant lymphoma, that has been difficult for imaging diagnosis so far. (author).

  9. Neptune Polar Orbiter with Probes

    Science.gov (United States)

    Bienstock, Bernard; Atkinson, David; Baines, Kevin; Mahaffy, Paul; Steffes, Paul; Atreya, Sushil; Stern, Alan; Wright, Michael; Willenberg, Harvey; Smith, David; hide

    2005-01-01

    The giant planets of the outer solar system divide into two distinct classes: the gas giants Jupiter and Saturn, which consist mainly of hydrogen and helium; and the ice giants Uranus and Neptune, which are believed to contain significant amounts of the heavier elements oxygen, nitrogen, and carbon and sulfur. Detailed comparisons of the internal structures and compositions of the gas giants with those of the ice giants will yield valuable insights into the processes that formed the solar system and, perhaps, other planetary systems. By 2012, Galileo, Cassini and possibly a Jupiter Orbiter mission with microwave radiometers, Juno, in the New Frontiers program, will have yielded significant information on the chemical and physical properties of Jupiter and Saturn. A Neptune Orbiter with Probes (NOP) mission would deliver the corresponding key data for an ice giant planet. Such a mission would ideally study the deep Neptune atmosphere to pressures approaching and possibly exceeding 1000 bars, as well as the rings, Triton, Nereid, and Neptune s other icy satellites. A potential source of power would be nuclear electric propulsion (NEP). Such an ambitious mission requires that a number of technical issues be investigated, however, including: (1) atmospheric entry probe thermal protection system (TPS) design, (2) probe structural design including seals, windows, penetrations and pressure vessel, (3) digital, RF subsystem, and overall communication link design for long term operation in the very extreme environment of Neptune's deep atmosphere, (4) trajectory design allowing probe release on a trajectory to impact Neptune while allowing the spacecraft to achieve a polar orbit of Neptune, (5) and finally the suite of science instruments enabled by the probe technology to explore the depths of the Neptune atmosphere. Another driving factor in the design of the Orbiter and Probes is the necessity to maintain a fully operational flight system during the lengthy transit time

  10. Orbital socket contracture: a complication of inflammatory orbital disease in patients with Wegener’s granulomatosis

    Science.gov (United States)

    Talar-Williams, C; Sneller, M C; Langford, C A; Smith, J A; Cox, T A; Robinson, M R

    2005-01-01

    Aim: To describe the clinical characteristics of orbital socket contracture in patients with Wegener’s granulomatosis (WG). Methods: A retrospective cohort study The medical records of 256 patients with WG examined at the National Institutes of Health from 1967 to 2004 were reviewed to identify patients with orbital socket contracture. Details of the orbital disease including Hertel exophthalmometry readings, radiological findings, and results of eye examinations were recorded. Orbital socket contracture was defined as orbital inflammation with proptosis followed by the development of enophthalmos and radiographic evidence of residual fibrotic changes in the orbit. To examine for risk factors in the development of a contracted orbit, patients with orbital socket contracture were compared to patients without contracture with respect to multiple variables including history of orbital surgery, orbital disease severity, and major organ system involvement. The main outcome measures were the clinical characteristics of orbital socket contracture associated with inflammatory orbital disease in patients with WG. Results: Inflammatory orbital disease occurred in 34 of 256 (13%) patients and detailed clinical data on 18 patients were available and examined. Orbital socket contracture occurred during the clinical course in six patients; the features included restrictive ophthalmopathy (five), chronic orbital pain (three), and ischaemic optic nerve disease (two) resulting in blindness (no light perception) in one patient. The orbital socket contracture occurred within 3 months of treatment with immunosuppressive medications for inflammatory orbital disease in five patients and was not responsive to immunosuppressive medications. The median degree of enophthalmos in the contracted orbit compared with the fellow eye was 2.8 mm (range 1.5–3.5 mm) by Hertel exophthalmometry. There were no risk factors that predicted development of orbital socket contracture. Conclusions: In

  11. Role of Negative Orbit Vector in Orbital Blow-Out Fractures.

    Science.gov (United States)

    Choi, Soo Youn; Lee, Hwa; Baek, Sehyun

    2017-11-01

    Negative orbit vector is defined as the most anterior globe portion protrudes past the malar eminence. The aim of the study was to evaluate the relationship between negative orbit vector and blow-out fracture location analyzing the distance between the anterior corneal surface and orbital bone with facial soft tissue in medial and orbital floor blow out fractures using orbital computed tomography (CT). Seventy-seven patients diagnosed with blow-out fractures involving the medial or orbital floor were included. Distances from the anterior cornea to lower lid fat, inferior orbital wall, inferior orbital rim, and anterior cheek mass were measured using orbital CT scans. The proportion of negative orbit vector and measured distanced were compared between medial wall fracture and orbital floor fracture. Medical records including age, sex, concomitant ophthalmic diagnosis, and nature of injury were retrospectively reviewed. Forty-three eyes from 43 patients diagnosed with medial wall fracture and 34 eyes from 34 patients diagnosed with orbital floor fracture were included. There was no significant difference in the distance from the anterior cornea to lower lid fat (P = 0.574), inferior orbital wall (P = 0.494), or orbital rim (P = 0.685). The distance from anterior cornea to anterior cheek mass was significantly different in medial wall fracture (-0.19 ± 3.49 mm) compared with orbital floor fracture (-1.69 ± 3.70 mm), P = 0.05. Negative orbit vector was significantly higher in orbital floor fracture patients (24 among 34 patients, 70.6%) compared with those with medial wall fractures (19 among 43 patients, 44.2%) (P = 0.04). Patients presenting with a negative orbit vector relationship when the most anterior portion of globe protruded past the anterior cheek mass and malar eminence were more likely to develop orbital floor fracture than medial wall fracture.

  12. The earth orbiting space debris

    Directory of Open Access Journals (Sweden)

    Rossi A.

    2005-01-01

    Full Text Available The space debris population is similar to the asteroid belt, since it is subject to a process of high-velocity mutual collisions that affects the long-term evolution of its size distribution. Presently, more than 10 000 artificial debris particles with diameters larger than 10 cm (and more than 300 000 with diameters larger than 1 cm are orbiting the Earth, and are monitored and studied by a large network of sensors around the Earth. Many objects of different kind compose the space debris population, produced by different source mechanisms ranging from high energy fragmentation of large spacecraft to slow diffusion of liquid metal. The impact against a space debris is a serious risk that every spacecraft must face now and it can be evaluated with ad-hoc algorithms. The long term evolution of the whole debris population is studied with computer models allowing the simulation of all the known source and sink mechanisms. One of these codes is described in this paper and the evolution of the debris environment over the next 100 years, under different traffic scenarios, is shown, pointing out the possible measures to mitigate the growth of the orbital debris population. .

  13. Investigations of SPS Orbit Drifts

    Energy Technology Data Exchange (ETDEWEB)

    Drøsdal, Lene [CERN; Bracco, Chiara [CERN; Cornelis, Karel [CERN; Goddard, Brennan [CERN; Kain, Verena [CERN; Meddahi, Malika [CERN; Wenninger, Jorg [CERN; Gianfelice-Wendt, Eliana [Fermilab

    2014-07-01

    The LHC is filled from the last pre-injector, the Super Proton Synchrotron (SPS), via two 3 km long transfer lines, TI 2 and TI 8. Over the LHC injection processes, a drift of the beam trajectories has been observed in TI 2 and TI 8, requiring regular correction of the trajectories, in order to ensure clean injection into the LHC. Investigations of the trajectory variations in the transfer lines showed that the main source of short term trajectory drifts are current variations of the SPS extraction septa (MSE). The stability of the power converters has been improved, but the variations are still present and further improvements are being investigated. The stability over a longer period of time cannot be explained by this source alone. The analysis of trajectory variations shows that there are also slow variations in the SPS closed orbit at extraction. A set of SPS orbit measurements has been saved and analysed. These observations will be used together with simulations and observed field errors to locate the second source of variations.

  14. Fungal infections of the orbit

    Directory of Open Access Journals (Sweden)

    Bipasha Mukherjee

    2016-01-01

    Full Text Available Fungal infections of the orbit can lead to grave complications. Although the primary site of inoculation of the infective organism is frequently the sinuses, the patients can initially present to the ophthalmologist with ocular signs and symptoms. Due to its varied and nonspecific clinical features, especially in the early stages, patients are frequently misdiagnosed and even treated with steroids which worsen the situation leading to dire consequences. Ophthalmologists should be familiar with the clinical spectrum of disease and the variable presentation of this infection, as early diagnosis and rapid institution of appropriate therapy are crucial elements in the management of this invasive sino-orbital infection. In this review, relevant clinical, microbiological, and imaging findings are discussed along with the current consensus on local and systemic management. We review the recent literature and provide a comprehensive analysis. In the immunocompromised, as well as in healthy patients, a high index of suspicion must be maintained as delay in diagnosis of fungal pathology may lead to disfiguring morbidity or even mortality. Obtaining adequate diagnostic material for pathological and microbiological examination is critical. Newer methods of therapy, particularly oral voriconazole and topical amphotericin B, may be beneficial in selected patients.

  15. Introducing the Moon's Orbital Eccentricity

    Science.gov (United States)

    Oostra, Benjamin

    2014-11-01

    I present a novel way to introduce the lunar orbital eccentricity in introductory astronomy courses. The Moon is perhaps the clearest illustration of the general orbital elements such as inclination, ascending node, eccentricity, perigee, and so on. Furthermore, I like the students to discover astronomical phenomena for themselves, by means of a guided exercise, rather than just telling them the facts.1 The inclination and nodes may be found by direct observation, monitoring carefully the position of the Moon among the stars. Even the regression of the nodes may be discovered in this way2 To find the eccentricity from students' observations is also possible,3 but that requires considerable time and effort. if a whole class should discover it in a short time, here is a method more suitable for a one-day class or home assignment. The level I aim at is, more or less, advanced high school or first-year college students. I assume them to be acquainted with celestial coordinates and the lunar phases, and to be able to use algebra and trigonometry.

  16. Investigations of SPS orbit drifts

    CERN Document Server

    Drøsdal, L; Cornelis, K; Goddard, B; Kain, V; Meddahi, M; Wenninger, J; Gianfelice-Wendt, E

    2014-01-01

    The LHC is filled from the last pre-injector, the Super Proton Synchrotron (SPS), via two 3 km long transfer lines, TI 2 and TI 8. Over the LHC injection processes, a drift of the beam trajectories has been observed in TI 2 and TI 8, requiring regular correction of the trajectories, in order to ensure clean injection into the LHC. Investigations of the trajectory variations in the transfer lines showed that the main source of short term trajectory drifts are current variations of the SPS extraction septa (MSE). The stability of the power converters has been improved, but the variations are still present and further improvements are being investigated. The stability over a longer period of time cannot be explained by this source alone. The analysis of trajectory variations shows that there are also slow variations in the SPS closed orbit at extraction. A set of SPS orbit measurements has been saved and analysed. These observations will be used together with simulations and observed field errors to locate the s...

  17. On-orbit Passive Thermography

    Science.gov (United States)

    Howell, Patricia A.; Winfree, William P.; Cramer, K. Elliott

    2008-01-01

    On July 12, 2006, British-born astronaut Piers Sellers became the first person to conduct thermal nondestructive evaluation experiments in space, demonstrating the feasibility of a new tool for detecting damage to the reinforced carbon-carbon (RCC) structures of the Shuttle. This new tool was an EVA (Extravehicular Activity, or spacewalk) compatible infrared camera developed by NASA engineers. Data was collected both on the wing leading edge of the Orbiter and on pre-damaged samples mounted in the Shuttle s cargo bay. A total of 10 infrared movies were collected during the EVA totaling over 250 megabytes of data. Images were downloaded from the orbiting Shuttle to Johnson Space Center for analysis and processing. Results are shown to be comparable to ground-based thermal inspections performed in the laboratory with the same type of camera and simulated solar heating. The EVA camera system detected flat-bottom holes as small as 2.54cm in diameter with 50% material loss from the back (hidden) surface in RCC during this first test of the EVA IR Camera. Data for the time history of the specimen temperature and the capability of the inspection system for imaging impact damage are presented.

  18. Pegging the porous orbital implant.

    Science.gov (United States)

    Johnson, Royce L C; Ramstead, Cory L; Nathoo, Nawaaz

    2011-01-01

    Hydroxyapatite (HA) orbital implants are commonly used for the anophthalmic socket. With a HA implant, if motility is not satisfactory then a peg system can be surgically placed in attempts to improve motility. The authors report the technique and results of 83 patients who received motility peg placement over an 8-year period by a single surgeon. Retrospective chart review of all patients with previous enucleation with either primary or secondary insertion of a HA implant who received a motility peg by a single oculoplastic surgeon between January 1999 and February 2007. Eighty-three patients underwent placement of a titanium peg and sleeve during the study period. Complications seen in the follow-up period included discharge, pyogenic granuloma, and others. Infection was experienced in 1 case. Fourteen patients (17%) required further surgical management due to complications. The largely positive results of this moderately sized case series validates the efficacy of pegging a hydroxyapatite orbital implant with minor risk of serious complications; this may have been due to a combination of factors including an experienced surgeon and adequate follow-up. As a procedure that can be completed in a hospital or minor surgical suite with sedation, it remains a viable option for many patients.

  19. Boxy Orbital Structures in Rotating Bar Models

    Science.gov (United States)

    Chaves-Velasquez, L.; Patsis, P. A.; Puerari, I.; Skokos, Ch.; Manos, T.

    2017-12-01

    We investigate regular and chaotic two-dimensional (2D) and three-dimensional (3D) orbits of stars in models of a galactic potential consisting of a disk, a halo, and a bar to find the origin of boxy components that are part of the bar or (almost) the bar itself. Our models originate in snapshots of an N-body simulation, which develops a strong bar. We consider three snapshots of the simulation, and, for the orbital study, we treat each snapshot independently, as an autonomous Hamiltonian system. The calculated corotation–to–bar length ratios indicate that in all three cases, the bar rotates slowly, while the orientation of the orbits of the main family of periodic orbits changes along its characteristic. We characterize the orbits as regular, sticky, or chaotic after integrating them for a 10 Gyr period by using the GALI2 index. Boxiness in the equatorial plane is associated either with quasi-periodic orbits in the outer parts of stability islands or with sticky orbits around them, which can be found in a large range of energies. We indicate the location of such orbits in diagrams, which include the characteristic of the main family. They are always found about the transition region from order to chaos. By perturbing such orbits in the vertical direction, we find a class of 3D nonperiodic orbits, which have boxy projections both in their face-on and side-on views.

  20. An analysis of near-circular lunar mapping orbits

    Indian Academy of Sciences (India)

    Keywords. Lunar mapping; orbit maintenance; orbit life time; lunar gravity model; spherical harmonics. ... The aim is to select the appropriate near-circular orbit characteristics,which extend orbit life through passive orbit maintenance.The spherical harmonic terms that make major contributions to the orbital behaviour are ...

  1. Orbit keeping attitude control for space station

    Science.gov (United States)

    Barrows, D.; Bedell, H.

    1983-01-01

    It is pointed out that on-orbit configuration variability is expected to be a characteristic of a space station. The implementation of such a chracteristic will present reboost and thruster control system designers with a number of new challenges. The primary requirement for the space station orbit reboost (or orbit keeping) system is to ensure system viability for extended duration and prevent an uncontrolled reentry as with Skylab. For a station in a low earth orbit, earodynamic drag will be sufficient to cause relatively quick orbit altitude decay. A propulsion system is, therefore, needed to counteract the aerodynamic drag forces and to boost the vehicle to the desired orbit altitudes. A description is given of a typical reboost operational procedure and propellant requirements. Attention is given to thruster control systems, and aspects of reboost guidance.

  2. Orbital Granulomatosis With Polyangiitis (Wegener Granulomatosis)

    Science.gov (United States)

    Muller, Karra; Lin, Jonathan H.

    2014-01-01

    The pathology of granulomatosis with polyangiitis (GPA), formerly Wegener granulomatosis, typically features a granulomatous and sometimes necrotizing vasculitis targeting the respiratory tract and kidneys. However, orbital involvement occurs in up to 60% of patients and is frequently the first or only clinical presentation in patients with systemic or limited forms of GPA. Orbital GPA can cause significant morbidity and potentially lead to complete loss of vision and permanent facial deformity. Fortunately, GPA is highly responsive to medical treatment with corticosteroids combined with cyclophosphamide or, more recently, rituximab. Therefore, it is imperative for this disease to be accurately diagnosed on orbital biopsy and distinguished from other histologically similar orbital lesions. Herein, we review the clinical and pathologic findings of orbital GPA, focusing on the differentiation of this disease from other inflammatory orbital lesions. PMID:25076302

  3. Growth and development of the orbit.

    Science.gov (United States)

    Berger, Aaron J; Kahn, David

    2012-11-01

    Every surgeon operating on the face, and particularly around the eye, should possess a working knowledge of the critical details related to development of the human orbit and recognized changes that occur during the course of aging. The anatomy of the orbit and periorbital region is complex, and the diagnosis and treatment of patients with orbital/periorbital disease requires expertise in congenital differences and awareness of the changes that occur as individuals age. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Orbital Debris and NASA's Measurement Program

    Science.gov (United States)

    Africano, J. L.; Stansbery, E. G.

    2002-05-01

    Since the launch of Sputnik in 1957, the number of manmade objects in orbit around the Earth has dramatically increased. The United States Space Surveillance Network (SSN) tracks and maintains orbits on over nine thousand objects down to a limiting diameter of about ten centimeters. Unfortunately, active spacecraft are only a small percentage ( ~ 7%) of this population. The rest of the population is orbital debris or ``space junk" consisting of expended rocket bodies, dead payloads, bits and pieces from satellite launches, and fragments from satellite breakups. The number of these smaller orbital debris objects increases rapidly with decreasing size. It is estimated that there are at least 130,000 orbital debris objects between one and ten centimeters in diameter. Most objects smaller than 10 centimeters go untracked! As the orbital debris population grows, the risk to other orbiting objects, most importantly manned space vehicles, of a collision with a piece of debris also grows. The kinetic energy of a solid 1 cm aluminum sphere traveling at an orbital velocity of 10 km/sec is equivalent to a 400 lb. safe traveling at 60 mph. Fortunately, the volume of space in which the orbiting population resides is large, collisions are infrequent, but they do occur. The Space Shuttle often returns to earth with its windshield pocked with small pits or craters caused by collisions with very small, sub-millimeter-size pieces of debris (paint flakes, particles from solid rocket exhaust, etc.), and micrometeoroids. To get a more complete picture of the orbital-debris environment, NASA has been using both radar and optical techniques to monitor the orbital debris environment. This paper gives an overview of the orbital debris environment and NASA's measurement program.

  5. Wavefunction Intensity Statistics from Unstable Periodic Orbits

    CERN Document Server

    Kaplan, L

    1998-01-01

    We examine the effect of short unstable periodic orbits on wavefunction statistics in a classically chaotic system, and find that the tail of the wavefunction intensity distribution in phase space is dominated by scarring associated with the least unstable periodic orbits. In an ensemble average over systems with classical orbits of different instabilities, a power law tail is found, in sharp contrast to the exponential prediction of random matrix theory. The calculations are compared with numerical data and quantitative agreement is obtained

  6. Mercury's resonant rotation from secular orbital elements

    OpenAIRE

    Stark, Alexander; Oberst, Jürgen; Hussmann, Hauke

    2015-01-01

    We used recently produced Solar System ephemerides, which incorporate 2 years of ranging observations to the MESSENGER spacecraft, to extract the secular orbital elements for Mercury and associated uncertainties. As Mercury is in a stable 3:2 spin-orbit resonance, these values constitute an important reference for the planet’s measured rotational parameters, which in turn strongly bear on physical interpretation of Mercury’s interior structure. In particular, we derive a mean orbital period o...

  7. Orbital motion effects in astrometric microlensing

    OpenAIRE

    Sajadian, Sedighe

    2014-01-01

    We investigate lens orbital motion in astrometric microlensing and its detectability. In microlensing events, the light centroid shift in the source trajectory (the astrometric trajectory) falls off much more slowly than the light amplification as the source distance from the lens position increases. As a result, perturbations developed with time such as lens orbital motion can make considerable deviations in astrometric trajectories. The rotation of the source trajectory due to lens orbital ...

  8. Mars Reconnaissance Orbiter Wrapper Script

    Science.gov (United States)

    Gladden, Roy; Fisher, Forest; Khanampornpan, Teerapat

    2008-01-01

    The MRO OLVM wrapper script software allows Mars Reconnaissance Orbiter (MRO) sequence and spacecraft engineers to rapidly simulate a spacecraft command product through a tool that simulates the onboard sequence management software (OLVM). This script parses sequence files to determine the appropriate time boundaries for the sequence, and constructs the script file to be executed by OLVM to span the entirety of the designated sequence. It then constructs script files to be executed by OLVM, constructs the appropriate file directories, populates these directories with needed input files, initiates OLVM to simulate the actual command product that will be sent to the spacecraft, and captures the results of the simulation run to an external file for later review. Additionally, the tool allows a user to manually construct the script, if desired, and then execute the script with a simple command line.

  9. Orbital actinomycotic mycetoma caused by

    Directory of Open Access Journals (Sweden)

    Stuart Walton

    2015-06-01

    Full Text Available Case summary An 18-month-old male neutered Ragdoll cat presented with an 8 week history of progressive unilateral right-sided mucopurulent nasal discharge and exophthalmos. Magnetic resonance imaging revealed a heterogeneous right retrobulbar mass and bilateral nasal cavity disease. Filamentous structures seen on cytology of retrobulbar and nasal biopsies were mistakenly identified as filamentous fungal hyphae. Subsequent investigations revealed that the cat had a retrobulbar actinomycotic mycetoma with invasion of the globe. The aetiological agent was identified on 16S recombinant DNA sequencing as Streptomyces cinnamoneus . After exenteration and chronic antimicrobial therapy the cat was alive and well 3 years after presentation. Relevance and novel information This is the first report of a pathogenic role of S cinnamoneus in a cat. Orbital actinomycotic mycetomas in cats can resemble mycotic granulomas.

  10. Orbit IMU alignment: Error analysis

    Science.gov (United States)

    Corson, R. W.

    1980-01-01

    A comprehensive accuracy analysis of orbit inertial measurement unit (IMU) alignments using the shuttle star trackers was completed and the results are presented. Monte Carlo techniques were used in a computer simulation of the IMU alignment hardware and software systems to: (1) determine the expected Space Transportation System 1 Flight (STS-1) manual mode IMU alignment accuracy; (2) investigate the accuracy of alignments in later shuttle flights when the automatic mode of star acquisition may be used; and (3) verify that an analytical model previously used for estimating the alignment error is a valid model. The analysis results do not differ significantly from expectations. The standard deviation in the IMU alignment error for STS-1 alignments was determined to the 68 arc seconds per axis. This corresponds to a 99.7% probability that the magnitude of the total alignment error is less than 258 arc seconds.

  11. Airbreathing Acceleration Toward Earth Orbit

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, J C

    2007-05-09

    As flight speed increases, aerodynamic drag rises more sharply than the availability of atmospheric oxygen. The ratio of oxygen mass flux to dynamic pressure cannot be improved by changing altitude. The maximum possible speed for airbreathing propulsion is limited by the ratio of air capture area to vehicle drag area, approximately Mach 6 at equal areas. Simulation of vehicle acceleration shows that the use of atmospheric oxygen offers a significant potential for minimizing onboard consumables at low speeds. These fundamental calculations indicate that a practical airbreathing launch vehicle would accelerate to near steady-state speed while consuming only onboard fuel, then transition to rocket propulsion. It is suggested that an aircraft carrying a rocket-propelled vehicle to approximately Mach 5 could be a realistic technical goal toward improving access to orbit.

  12. Mars Observer Orbit Insertion Briefing

    Science.gov (United States)

    1993-01-01

    Steve Wall is the host of this video entitled, "Return to the Red Planet". Live animation of the Mars Observer orbiting Mars is presented. Steve Wall explains the spacecraft insertion maneuver and also explains the purpose for the Mars Observer launch. Live coverage of the Cape Canaveral launch of the Mars Observer is also presented. Suzanne Dodd, Chief of the Mission Planning team describes the burn start and how the spacecraft will be captured by Mars' gravity. Glenn Cunningham, Mars Observer Project Manager, gives background information on the Mars Observer and describes the organizations behind the Mars Observer Spacecraft, such as the Deep Space Network, the Mission Operation Support Office, Science Investigators, the Flight Engineering Office, Operations Office, and the Ground Data System Office. Dr. William Piotrowski, Acting Director, Solar System Exploration Division, NASA, talks about the purpose of the Mars Pathfinder which is to develop the technology and systems for landing small science packages on Mars. Mr. Roger Gibbs, Former Mars Observer Spacecraft Systems Engineer, tells us how the Mars Observer was built and describes the structural elements on the Mars Observer. The 11-month cruise period for the spacecraft is given by Joseph Beerer, Manager of the Engineering office. The thrust for the Mars Orbit Insertion is described by Ronald Klemetson, Technical Manager, Propulsion Subsystem Jet Propulsion Laboratory (JPL). George Chen, Lead Engineer Attitude and Articulation Subsystem Spacecraft Team, explains the importance of the attitude control engines on the Spacecraft. Marvin Traxler, Manager of Tracking and Data Acquisition, describes how searching for a signal from the Mars Observer works. See NONP-NASA-VT-2000081555 for a continuation of this discussion with Marvin Traxler.

  13. CDDIS_GNSS_products_orbit_ultrarapid

    Data.gov (United States)

    National Aeronautics and Space Administration — Precise satellite orbits derived from analysis of Global Navigation Satellite System (GNSS) data. Analysis Centers (ACs) of the International GNSS Service (IGS)...

  14. CDDIS_GNSS_products_orbit_rapid

    Data.gov (United States)

    National Aeronautics and Space Administration — Precise satellite orbits derived from analysis of Global Navigation Satellite System (GNSS) data. Analysis Centers (ACs) of the International GNSS Service (IGS)...

  15. Orbit lifetime characteristics for Space Station

    Science.gov (United States)

    Deryder, L.; Kelly, G. M.; Heck, M.

    The factors that influence the orbital lifetime characteristics of the NASA Space Station are discussed. These include altitude, attitude, launch date, ballistic coefficient, and the presence of large articulating solar arrays. Examples from previous program systems studies are presented that illustrate how each factor affects Station orbit lifetime. The effect of atmospheric density models on orbit lifetime predictions is addressed along with the uncertainty of these predictions using current trajectory analysis of the Long Duration Exposure Facility spacecraft. Finally, nominal reboost altitude profiles and fuel requirement considerations are presented for implementing a reboost strategy based on planned Shuttle Orbiter rendezvous strategy and contingency considerations.

  16. CDDIS_GNSS_products_orbit_final

    Data.gov (United States)

    National Aeronautics and Space Administration — Precise satellite orbits derived from analysis of Global Navigation Satellite System (GNSS) data. Analysis Centers (ACs) of the International GNSS Service (IGS)...

  17. CDDIS_GNSS_products_orbit_realtime

    Data.gov (United States)

    National Aeronautics and Space Administration — Precise satellite orbits derived from analysis of Global Navigation Satellite System (GNSS) data. Analysis Centers (ACs) of the International GNSS Service (IGS)...

  18. Maneuver Estimation Model for Relative Orbit Determination

    National Research Council Canada - National Science Library

    Storch, Tara R

    2005-01-01

    While the use of relative orbit determination has reduced the difficulties inherent in tracking geosynchronous satellites that are in close proximity, the problem is often compounded by stationkeeping...

  19. Linear Magnetoelectric Effect by Orbital Magnetism

    OpenAIRE

    Scaramucci, A.; Bousquet, E.; Fechner, M.; Mostovoy, M.; Spaldin, N. A.

    2012-01-01

    We use symmetry analysis and first principles calculations to show that the linear magnetoelectric effect can originate from the response of orbital magnetic moments to the polar distortions induced by an applied electric field. Using LiFePO4 as a model compound we show that spin-orbit coupling partially lifts the quenching of the 3d orbitals and causes small orbital magnetic moments ($\\mu_{(L)}\\approx 0.3 \\mu_B$) parallel to the spins of the Fe$^{2+}$ ions. An applied electric field $\\mathbf...

  20. The fundamental group of the orbit space

    Directory of Open Access Journals (Sweden)

    Hattab Hawete

    2015-12-01

    Full Text Available Let G be a subgroup of the group Homeo(X of homeomorphisms of a topological space X. Let G¯$\\bar G$ be the closure of G in Homeo(X. The class of an orbit O of G is the union of all orbits having the same closure as O. We denote by X/G˜$X/\\widetildeG$ the space of classes of orbits called the orbit class space. In this paper, we study the fundamental group of the spaces X/G, X/G¯$X/\\bar G$ and X/G˜$X/\\widetildeG$

  1. GOCE Satellite Orbit in a Computational Aspect

    Science.gov (United States)

    Bobojc, Andrzej; Drozyner, Andrzej

    2013-04-01

    The presented work plays an important role in research of possibility of the Gravity Field and Steady-State Ocean Circulation Explorer Mission (GOCE) satellite orbit improvement using a combination of satellite to satellite tracking high-low (SST- hl) observations and gravity gradient tensor (GGT) measurements. The orbit improvement process will be started from a computed orbit, which should be close to a reference ("true") orbit as much as possible. To realize this objective, various variants of GOCE orbit were generated by means of the Torun Orbit Processor (TOP) software package. The TOP software is based on the Cowell 8th order numerical integration method. This package computes a satellite orbit in the field of gravitational and non-gravitational forces (including the relativistic and empirical accelerations). The three sets of 1-day orbital arcs were computed using selected geopotential models and additional accelerations generated by the Moon, the Sun, the planets, the Earth and ocean tides, the relativity effects. Selected gravity field models include, among other things, the recent models from the GOCE mission and the models such as EIGEN-6S, EIGEN-5S, EIGEN-51C, ITG-GRACE2010S, EGM2008, EGM96. Each set of 1-day orbital arcs corresponds to the GOCE orbit for arbitrary chosen date. The obtained orbits were compared to the GOCE reference orbits (Precise Science Orbits of the GOCE satellite delivered by the European Space Agency) using the root mean squares (RMS) of the differences between the satellite positions in the computed orbits and in the reference ones. These RMS values are a measure of performance of selected geopotential models in terms of GOCE orbit computation. The RMS values are given for the truncated and whole geopotential models. For the three variants with the best fit to the reference orbits, the empirical acceleration models were added to the satellite motion model. It allowed for further improving the fitting of computed orbits to the

  2. Precise Orbit Determination of the Lunar Reconnaissance Orbiter and inferred gravity field information

    Science.gov (United States)

    Maier, A.; Baur, O.; Krauss, S.

    2014-04-01

    This contribution deals with Precise Orbit Determination of the Lunar Reconnaissance Orbiter, which is tracked with optical laser ranges in addition to radiometric Doppler range-rates and range observations. The optimum parameterization is assessed by overlap analysis tests that indicate the inner precision of the computed orbits. Information about the very long wavelengths of the lunar gravity field is inferred from the spacecraft positions. The NASA software packages GEODYN II and SOLVE were used for orbit determination and gravity field recovery [1].

  3. Validation of Galileo orbits using SLR with a focus on satellites launched into incorrect orbital planes

    Science.gov (United States)

    Sośnica, Krzysztof; Prange, Lars; Kaźmierski, Kamil; Bury, Grzegorz; Drożdżewski, Mateusz; Zajdel, Radosław; Hadas, Tomasz

    2017-07-01

    The space segment of the European Global Navigation Satellite System (GNSS) Galileo consists of In-Orbit Validation (IOV) and Full Operational Capability (FOC) spacecraft. The first pair of FOC satellites was launched into an incorrect, highly eccentric orbital plane with a lower than nominal inclination angle. All Galileo satellites are equipped with satellite laser ranging (SLR) retroreflectors which allow, for example, for the assessment of the orbit quality or for the SLR-GNSS co-location in space. The number of SLR observations to Galileo satellites has been continuously increasing thanks to a series of intensive campaigns devoted to SLR tracking of GNSS satellites initiated by the International Laser Ranging Service. This paper assesses systematic effects and quality of Galileo orbits using SLR data with a main focus on Galileo satellites launched into incorrect orbits. We compare the SLR observations with respect to microwave-based Galileo orbits generated by the Center for Orbit Determination in Europe (CODE) in the framework of the International GNSS Service Multi-GNSS Experiment for the period 2014.0-2016.5. We analyze the SLR signature effect, which is characterized by the dependency of SLR residuals with respect to various incidence angles of laser beams for stations equipped with single-photon and multi-photon detectors. Surprisingly, the CODE orbit quality of satellites in the incorrect orbital planes is not worse than that of nominal FOC and IOV orbits. The RMS of SLR residuals is even lower by 5.0 and 1.5 mm for satellites in the incorrect orbital planes than for FOC and IOV satellites, respectively. The mean SLR offsets equal -44.9, -35.0 , and -22.4 mm for IOV, FOC, and satellites in the incorrect orbital plane. Finally, we found that the empirical orbit models, which were originally designed for precise orbit determination of GNSS satellites in circular orbits, provide fully appropriate results also for highly eccentric orbits with variable

  4. On the Mitigation of Solar Index Variability for High Precision Orbit Determination in Low Earth Orbit

    Science.gov (United States)

    2016-09-16

    causing increased difficulty in achieving and maintaining high precision orbit predictions for satellites operating in low Earth orbit . In particular, the...Geodetic satellites with high precision satellite laser ranging data are used as test cases for the Naval Research Laboratory’s Orbit Covariance Estimation...forces imparted upon a satellite . For satellites in Low Earth Orbit (LEO), atmospheric drag forces are typically the largest source of force modeling error

  5. An orbital masquerade syndrome: A case report

    African Journals Online (AJOL)

    3. Fezza J, Chaudhry I A, Kwon Y H, Grannum E E, Sinard J and. Wolfley D E. Orbital melanoma presenting as orl ital cellulitis: a clinicopathologic report. Ophthal Plast Recons tr Surg 1998;. 14: 28 6-9. 4. Seedat R Y, Hamilton P D, de Jager L P, Strvdoni W and. Beukes C A. Orbital rhabdomyosarcoma preser ting as an ap-.

  6. Numerical bifurcation of Hamiltonian relative periodic orbits

    DEFF Research Database (Denmark)

    Wulff, Claudia; Schilder, Frank

    2009-01-01

    Relative periodic orbits (RPOs) are ubiquitous in symmetric Hamiltonian systems and occur, for example, in celestial mechanics, molecular dynamics, and the motion of rigid bodies. RPOs are solutions which are periodic orbits of the symmetry-reduced system. In this paper we analyze certain symmetry...

  7. Orbiter Water Dump Nozzles Redesign Lessons Learned

    Science.gov (United States)

    Rotter, Hank

    2017-01-01

    Hank Rotter, NASA Technical Fellow for Environmental Control and Life Support System, will provide the causes and lessons learned for the two Space Shuttle Orbiter water dump icicles that formed on the side of the Orbiter. He will present the root causes and the criticality of these icicles, along with the redesign of the water dump nozzles and lessons learned during the redesign phase.

  8. Third-generation muffin–tin orbitals

    Indian Academy of Sciences (India)

    generation muffin–tin orbitals (MTOs) are. We demonstrate that they can be downfolded to smaller and smaller basis sets: s p 3 d 10 , s p 3 , and bond orbitals. For isolated bands, it is possible to generate Wannier functions a priori. Also for bands ...

  9. Computed tomography (CT) of orbital cellulitis

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, H.; Hara, K.; Okamura, R.; Watanabe, T.; Nagata, M. (Kumamoto Univ. (Japan). School of Medicine)

    1981-12-01

    Two cases of orbital cellulitis showed a tumor-like shadow in the orbit on CT examination. Abnormal shadows were also noticed in both cases in the frontal and ethmoid sinuses. Postoperatively, one case was diagnosed as pyocele of the frontal sinus, the other as sinusitis with subperitoneal hematoma. In these diagnoses, plane skull X-P, tomography and CT scanning were valuable.

  10. Extraskeletal Myxoid Chondrosarcoma of the Orbit.

    Science.gov (United States)

    Al-Osaily, Abdullah M; Al-Dosari, Faisal N; Elewa, Mostaf A; Butt, Sohail A

    2016-01-01

    Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft tissue tumor. Numerous cases of EMC have been reported in different anatomical locations. There is currently only a single case of EMC of the orbit and that was reported in 1985. We report a second case of orbital EMC in a 34-year-old healthy male.

  11. Linear Magnetoelectric Effect by Orbital Magnetism

    NARCIS (Netherlands)

    Scaramucci, A.; Bousquet, E.; Fechner, M.; Mostovoy, M.; Spaldin, N. A.

    2012-01-01

    We use symmetry analysis and first-principles calculations to show that the linear magnetoelectric effect can originate from the response of orbital magnetic moments to the polar distortions induced by an applied electric field. Using LiFePO4 as a model compound we show that spin-orbit coupling

  12. Posttraumatic orbital emphysema: a numerical model.

    Science.gov (United States)

    Skorek, Andrzej; Kłosowski, Paweł; Plichta, Lukasz; Raczyńska, Dorota; Zmuda Trzebiatowski, Marcin; Lemski, Paweł

    2014-01-01

    Orbital emphysema is a common symptom accompanying orbital fracture. The pathomechanism is still not recognized and the usually assumed cause, elevated pressure in the upper airways connected with sneezing or coughing, does not always contribute to the occurrence of this type of fracture. Observations based on the finite model (simulating blowout type fracture) of the deformations of the inferior orbital wall after a strike in its lower rim. Authors created a computer numeric model of the orbit with specified features-thickness and resilience modulus. During simulation an evenly spread 14400 N force was applied to the nodular points in the inferior rim (the maximal value not causing cracking of the outer rim, but only ruptures in the inferior wall). The observation was made from 1 · 10(-3) to 1 · 10(-2) second after a strike. Right after a strike dislocations of the inferior orbital wall toward the maxillary sinus were observed. Afterwards a retrograde wave of the dislocation of the inferior wall toward the orbit was noticed. Overall dislocation amplitude reached about 6 mm. Based on a numeric model of the orbit submitted to a strike in the inferior wall an existence of a retrograde shock wave causing orbital emphysema has been found.

  13. Posttraumatic Orbital Emphysema: A Numerical Model

    Directory of Open Access Journals (Sweden)

    Andrzej Skorek

    2014-01-01

    Full Text Available Orbital emphysema is a common symptom accompanying orbital fracture. The pathomechanism is still not recognized and the usually assumed cause, elevated pressure in the upper airways connected with sneezing or coughing, does not always contribute to the occurrence of this type of fracture. Observations based on the finite model (simulating blowout type fracture of the deformations of the inferior orbital wall after a strike in its lower rim. Authors created a computer numeric model of the orbit with specified features—thickness and resilience modulus. During simulation an evenly spread 14400 N force was applied to the nodular points in the inferior rim (the maximal value not causing cracking of the outer rim, but only ruptures in the inferior wall. The observation was made from 1·10-3 to 1·10-2 second after a strike. Right after a strike dislocations of the inferior orbital wall toward the maxillary sinus were observed. Afterwards a retrograde wave of the dislocation of the inferior wall toward the orbit was noticed. Overall dislocation amplitude reached about 6 mm. Based on a numeric model of the orbit submitted to a strike in the inferior wall an existence of a retrograde shock wave causing orbital emphysema has been found.

  14. Objective measurement of motion in the orbit

    NARCIS (Netherlands)

    Abramoff, M.D.

    2001-01-01

    The research described in the thesis had two major aims: to find methods for objective measurement of motion in the orbit, and to determine the clinical use of these methods in patients with orbital disorders. This implied that a number of research questions had to be answered in the fields of both

  15. Orbital angular momentum: a personal memoir

    Science.gov (United States)

    Allen, L.

    2017-02-01

    A definitive statement of the model used to describe orbital angular momentum is essentially now available. Its early history, and the interaction of those who played key roles in its development over 20 years ago in its development, is outlined in this Memoir. This article is part of the themed issue 'Optical orbital angular momentum'.

  16. Inverse-Square Orbits: A Geometric Approach.

    Science.gov (United States)

    Rainwater, James C.; Weinstock, Robert

    1979-01-01

    Presents a derivation of Kepler's first law of planetary motion from Newtonian principles. Analogus derivations of the hyperbolic and parabolic orbits of nonreturning comets and the hyperbolic orbit for a particle in a repulsive inverse-square field are also presented. (HM)

  17. Orbital decomposition of CALIFA spiral galaxies

    Science.gov (United States)

    Zhu, Ling; van den Bosch, Remco; van de Ven, Glenn; Lyubenova, Mariya; Falcón-Barroso, Jesús; Meidt, Sharon E.; Martig, Marie; Shen, Juntai; Li, Zhao-Yu; Yildirim, Akin; Walcher, C. Jakob; Sanchez, Sebastian F.

    2018-01-01

    Schwarzschild orbit-based dynamical models are widely used to uncover the internal dynamics of early-type galaxies and globular clusters. Here we present for the first time the Schwarzschild models of late-type galaxies: an SBb galaxy NGC 4210 and an S0 galaxy NGC 6278 from the Calar Alto Legacy Integral Field Area (CALIFA) survey. The mass profiles within 2Re are constrained well with 1σ statistical error of ˜ 10 per cent. The luminous and dark mass can be disentangled with uncertainties of ˜20 and ˜ 50 per cent, respectively. From Re to 2Re, the dark matter fraction increases from 14 ± 10 to 18 ± 10 per cent for NGC 4210 and from 15 ± 10 to 30 ± 20 per cent for NGC 6278. The velocity anisotropy profiles of both σr/σt and σz/σR are well constrained. The inferred internal orbital distributions reveal clear substructures. The orbits are naturally separated into three components: a cold component with near circular orbits; a hot component with near radial orbits and a warm component in between. The photometrically identified exponential discs are predominantly made up of cold orbits only beyond ˜1Re, while they are constructed mainly with the warm orbits inside. Our dynamical hot components are concentrated in the inner regions, similar to the photometrically identified bulges. The reliability of the results, especially the orbit distribution, is verified by applying the model to mock data.

  18. Ejection-collision orbits in the RTBP

    Science.gov (United States)

    Ollé, Mercè; Rodríguez, Òscar; Soler, Jaume

    2018-02-01

    In this paper we analyse the ejection-collision (EC) orbits of the planar restricted three body problem. Being μ ∈ (0, 0.5] the mass parameter, and taking the big (small) primary with mass 1 - μ (μ), an EC orbit will be an orbit that ejects from the big primary, does an excursion and collides with it. As it is well known, for any value of the mass parameter μ ∈ (0, 0.5] and sufficiently restricted Hill regions (that is, for big enough values of the Jacobi constant C), there are exactly four EC orbits. We check their existence and extend numerically these four orbits for μ ∈ (0, 0.5] and for smaller values of the Jacobi constant. We introduce the concept of n-ejection-collision orbits (n-EC orbits) and we explore them numerically for μ ∈ (0, 0.5] and values of the Jacobi constant such that the Hill bounded possible region of motion contains the big primary and does not contain the small one. We study the cases 1 ≤ n ≤ 10 and we analyse the continuation of families of such n-EC orbits, varying the energy, as well as the bifurcations that appear.

  19. Optimal parking orbits for manned Mars missions

    Science.gov (United States)

    Cupples, Michael L.; Nordwall, Jill A.

    This paper summarizes a Mars parking orbit optimization effort. This parking orbit study includes the selection of optimal elliptic Mars parking orbits that meet mission constraints and that include pertinent apsidal misalignment losses. Mars missions examined are for the opportunity years of 2014, 2016, and 2018. For these mission opportunities, it is shown that the optimal parking orbits depend on the year that the mission occurs and are coupled with the outbound, Mars stay, and return phases of the mission. Constraints included in the parking orbit optimization process are periapsis lighting angle (related to a daylight landing requirement), periapsis latitude (related to a landing latitude range requirement) and the vehicle Trans-Earth-Injection stage mass. Also, effects of mission abort requirements on optimal parking orbits are investigated. Off-periapsis maneuvers for Mars orbit capture were found to be cost effective in reducing the mission delta-V for the 2016 abort from Mars capture scenario. The total capture and departure delta-V was `split' between the capture maneuver and the departure maneuver to reduce the 2016 Mars departure delta-V to below the level of the corresponding stage of the 2014 baseline mission. Landing results are provided that show Mars landing site access from the optimal elliptic parking orbits for Mars excursion vehicles with low (0.2) and high (1.3 and 1.6) lift to drag ratio.

  20. Cometary Orbital Trends with Spitzer

    Science.gov (United States)

    Kelley, Michael S.; Bodewits, Dennis; Feaga, Lori M.; Knight, Matthew M.; McKay, Adam; Snodgrass, Colin; Wooden, Diane H.; Bauer, James M.

    2017-10-01

    Cometary mass-loss, i.e., activity, is nominally driven by the sublimation of volatiles. The three most abundant volatiles in the average comet are water, carbon dioxide, and carbon monoxide. Of the three, CO2 is the most challenging to measure directly, and cannot be observed from the ground due to telluric absorptions. Owing to observations made by several space telescopes, including ISO, Spitzer, Akari, and WISE, as well as spacecraft missions to comets, we have a good estimate of the range of CO2 abundances in the comet population (~5-30% with respect to water). However, spacecraft missions have shown that the production of H2O, CO2 and CO are not fully understood. At each of three well-studied comets (9P/Tempel 1, 103P/Hartley 2, and 67P/Churyumov-Gerasimenko), CO2 and H2O have had distinct distributions in the coma, suggesting different release mechanisms or heterogeneous source regions. For 67P, this resulted in relative abundances that varied along the comet’s orbit, demonstrating that a single measurement of the CO2-to-water abundance ratio in a cometary coma is not necessarily reflective of the bulk nucleus composition.To improve our understanding of CO2 production in comets, we began a time-domain survey of 24 targets with the Spitzer Space Telescope in 2015. Most targets are observed multiple times on month-long timescales, and some comets are observed on year-long timescales. We present a summary of the Spitzer project at the 2.5-year mark, including total CO2 production rates at heliocentric distances beyond 3 au, number and size of CO2 active areas, and seasonal variations in dust and CO2 production. We also compare the Spitzer results to comets observed in the NEOWISE survey (Bauer et al. 2017, this meeting). The NEOWISE data is complementary in that it provides observations of many targets with limited selection biases, whereas the Orbital Trends Survey observes a small number of targets in detail.This work is based on observations made with the

  1. Intracranial Infectious Aneurysm in Orbital Cellulitis.

    Science.gov (United States)

    Lee, Brian; Kim, Charles; Carrasco, Jacqueline

    2015-01-01

    Infectious intracranial aneurysm and cavernous sinus thrombosis are rare complications of orbital cellulitis. We report the case of a 46-year-old male presenting with sinusitis and orbital cellulitis complicated by the development of an orbital mass. Following orbitotomy with debulking, the patient underwent bony orbital decompression for increasing proptosis postoperatively. While his exam stabilized, the patient developed complete ptosis and extraocular motor palsy in the contralateral eye after undergoing bilateral sinus debridement. Imaging was notable for the presence of a pseudoaneurysm of the internal carotid artery, which was treated with a stent. This report demonstrates rare complications of orbital cellulitis. These patients should be monitored carefully with noninvasive imaging studies, such as cerebral angiography, for early detection of vascular abnormalities that can progress rapidly.

  2. Continuation of Sets of Constrained Orbit Segments

    DEFF Research Database (Denmark)

    Schilder, Frank; Brøns, Morten; Chamoun, George Chaouki

    Sets of constrained orbit segments of time continuous flows are collections of trajectories that represent a whole or parts of an invariant set. A non-trivial but simple example is a homoclinic orbit. A typical representation of this set consists of an equilibrium point of the flow and a trajectory...... that starts close and returns close to this fixed point within finite time. More complicated examples are hybrid periodic orbits of piecewise smooth systems or quasi-periodic invariant tori. Even though it is possible to define generalised two-point boundary value problems for computing sets of constrained...... orbit segments, this is very disadvantageous in practice. In this talk we will present an algorithm that allows the efficient continuation of sets of constrained orbit segments together with the solution of the full variational problem....

  3. CASA Uno GPS orbit and baseline experiments

    Science.gov (United States)

    Schutz, B. E.; Ho, C. S.; Abusali, P. A. M.; Tapley, B. D.

    1990-01-01

    CASA Uno data from sites distributed in longitude from Australia to Europe have been used to determine orbits of the GPS satellites. The characteristics of the orbits determined from double difference phase have been evaluated through comparisons of two-week solutions with one-week solutions and by comparisons of predicted and estimated orbits. Evidence of unmodeled effects is demonstrated, particularly associated with the orbit planes that experience solar eclipse. The orbit accuracy has been assessed through the repeatability of unconstrained estimated baseline vectors ranging from 245 km to 5400 km. Both the baseline repeatability and the comparison with independent space geodetic methods give results at the level of 1-2 parts in 100,000,000. In addition, the Mojave/Owens Valley (245 km) and Kokee Park/Ft. Davis (5409 km) estimates agree with VLBI and SLR to better than 1 part in 100,000,000.

  4. Linear Magnetoelectric Effect by Orbital Magnetism

    Science.gov (United States)

    Scaramucci, Andrea; Bousquet, Eric; Fechner, Michael; Mostovoy, Maxim; Spaldin, Nicola

    2013-03-01

    The linear magnetoelectric effect is the linear induction of a static magnetization (electric polarization) by an applied static electric (magnetic) field. Using symmetry analysis and ab initio calculations we show that, in addition to mechanisms involving magnetic moments of spins, such an effect can originate from the response of orbital magnetic moment to polar distortions induced by an applied electric field. Considering LiFePO4 as model compound, we show that spin-orbit coupling partially lifts the quenching of 3d orbitals and causes small orbital magnetic moments at the magnetic ions sites. An applied electric field modifies the sizes of these orbital magnetic moments and results in a net magnetization. Furthermore, we discuss the link between this mechanism and the electric field dependence of magnetocrystalline anisotropy.

  5. Small Orbital Stereo Tracking Camera Technology Development

    Science.gov (United States)

    Bryan, Tom; MacLeod, Todd; Gagliano, Larry

    2017-01-01

    Any exploration vehicle assembled or Spacecraft placed in LEO or GTO must pass through this debris cloud and survive. Large cross section, low thrust vehicles will spend more time spiraling out through the cloud and will suffer more impacts.Better knowledge of small debris will improve survival odds. Current estimated Density of debris at various orbital attitudes with notation of recent collisions and resulting spikes. Orbital Debris Tracking and Characterization has now been added to NASA Office of Chief Technologists Technology Development Roadmap in Technology Area 5 (TA5.7)[Orbital Debris Tracking and Characterization] and is a technical gap in the current National Space Situational Awareness necessary to safeguard orbital assets and crews due to the risk of Orbital Debris damage to ISS Exploration vehicles. The Problem: Traditional orbital trackers looking for small, dim orbital derelicts and debris typically will stare at the stars and let any reflected light off the debris integrate in the imager for seconds, thus creating a streak across the image. The Solution: The Small Tracker will see Stars and other celestial objects rise through its Field of View (FOV) at the rotational rate of its orbit, but the glint off of orbital objects will move through the FOV at different rates and directions. Debris on a head-on collision course (or close) will stay in the FOV at 14 Km per sec. The Small Tracker can track at 60 frames per sec allowing up to 30 fixes before a near-miss pass. A Stereo pair of Small Trackers can provide range data within 5-7 Km for better orbit measurements.

  6. The Solar Poynting-Robertson Effect On Particles Orbiting Solar System Bodies: Circular Orbits

    Science.gov (United States)

    Rubincam, David P.

    2013-01-01

    The Poynting-Robertson effect from sunlight impinging directly on a particle which orbits a Solar System body (planet, asteroid, comet) is considered from the Sun's rest frame. There appear to be no significant first-order terms in V(sub b)/c for circular orbits, where V(sub b) is the body's speed in its orbit about the Sun and c is the speed of light, when the particle's orbital semimajor axis is much smaller than the body's orbital semimajor axis about the Sun as is mainly the case in the Solar System.

  7. Theory and design methods of special space orbits

    CERN Document Server

    Zhang, Yasheng; Zhou, Haijun

    2017-01-01

    This book focuses on the theory and design of special space orbits. Offering a systematic and detailed introduction to the hovering orbit, spiral cruising orbit, multi-target rendezvous orbit, initiative approaching orbit, responsive orbit and earth pole-sitter orbit, it also discusses the concept, theory, design methods and application of special space orbits, particularly the design and control method based on kinematics and astrodynamics. In addition the book presents the latest research and its application in space missions. It is intended for researchers, engineers and postgraduates, especially those working in the fields of orbit design and control, as well as space-mission planning and research.

  8. Geostationary Orbit Surveillance Using the Unscented Kalman Filter and the Analytical Orbit Model

    Directory of Open Access Journals (Sweden)

    Kyoung-Min Roh

    2011-09-01

    Full Text Available A strategy for geostationary orbit (or geostationary earth orbit [GEO] surveillance based on optical angular observations is presented in this study. For the dynamic model, precise analytical orbit model developed by Lee et al. (1997 is used to improve computation performance and the unscented Kalman filer (UKF is applied as a real-time filtering method. The UKF is known to perform well under highly nonlinear conditions such as surveillance in this study. The strategy that combines the analytical orbit propagation model and the UKF is tested for various conditions like different level of initial error and different level of measurement noise. The dependencies on observation interval and number of ground station are also tested. The test results shows that the GEO orbit determination based on the UKF and the analytical orbit model can be applied to GEO orbit tracking and surveillance effectively.

  9. Satellite orbits design using frequency analysis

    Science.gov (United States)

    Noullez, A.; Tsiganis, K.; Tzirti, S.

    2015-07-01

    We present here a new method for the efficient computation of periodic orbits, which are of particular interest for low-altitude satellite orbits design in high degree/order, non-axisymmetric gravity models. Our method consists of an iterative filtering scheme, that is itself based on 'Prony's method' of frequency analysis, and is independent of the complexity of the gravity model. Applying this method to the case of a low-altitude lunar orbiter, we show that it converges rapidly, in all models and for all values of altitude and initial inclination studied. Thus, as demonstrated below, one could use it to correct the initial conditions of a desired mission orbit - usually defined within the framework of a simplified model (e.g. the 'J2 problem') - ensuring minimal orbital eccentricity variations and, for very low altitudes, collision avoidance. At the same time, an accurate quasi-periodic decomposition of the orbit is computed, giving a measure of the periodic fluctuations of the orbital parameters.

  10. Distant retrograde orbits and the asteroid hazard

    Science.gov (United States)

    Perozzi, Ettore; Ceccaroni, Marta; Valsecchi, Giovanni B.; Rossi, Alessandro

    2017-08-01

    Distant Retrograde Orbits (DROs) gained a novel wave of fame in space mission design because of their numerous advantages within the framework of the US plans for bringing a large asteroid sample in the vicinity of the Earth as the next target for human exploration. DROs are stable solutions of the three-body problem that can be used whenever an object, whether of natural or artificial nature, is required to remain in the neighborhood of a celestial body without being gravitationally captured by it. As such, they represent an alternative option to Halo orbits around the collinear Lagrangian points L1 and L2. Also known under other names ( e.g., quasi-satellite orbits, cis-lunar orbits, family- f orbits) these orbital configurations found interesting applications in several mission profiles, like that of a spacecraft orbiting around the small irregularly shaped satellite of Mars Phobos or the large Jovian moon Europa. In this paper a basic explanation of the DRO dynamics is presented in order to clarify some geometrical properties that characterize them. Their accessibility is then discussed from the point of view of mission analysis under different assumptions. Finally, their relevance within the framework of the present asteroid hazard protection programs is shown, stressing the significant increase in warning time they would provide in the prediction of impactors coming from the direction of the Sun.

  11. Orbital apocrine hidrocystoma with immunohistochemical confirmation

    Directory of Open Access Journals (Sweden)

    Eduardo Damous Feijó

    2016-06-01

    Full Text Available ABSTRACT The authors report the first case in Brazilian literature of orbital apocrine hidrocystoma with immunohistochemistry confirmation. The tumor had been growing slowly and progressively, there was no history of impaired vision, diplopia, watering, discharge, or prior trauma. There was no proptosis and extraocular mobility was normal. The radiologic study by orbital computerized tomography revealed an extraconal nodule, with partially defined limits, with cystic and solid areas in the superomedial right orbit. An anterior orbitotomy, with full excision of the tumor was performed. A histopathology examination revealed apocrine hidrocystoma and immunohistochemistry confirmed the diagnosis. After surgery, the patient had total remission of symptoms.

  12. Displaying New Measurements on WDS Orbit Plots

    Science.gov (United States)

    Buchheim, Robert

    2017-04-01

    Students who observe and measure a visual double star often want to see how their measurement compares with the historical record and with the orbit (if one has been determined). This paper describes how PowerPoint’s graphical tools can display a newly-measured data point on the orbit plot from USNO’s 6th Orbit Catalog, and how a simple spreadsheet can transform measurements expressed as (rho,theta) into a Cartesian plot of the sky positions (E, N). This information is presented as a resource for future students.

  13. Established meteor shower activity periods and orbits

    Science.gov (United States)

    Roggemans, Paul

    2017-02-01

    The CAMS dataset of 111233 orbits collected in the period 2010-2013 has been checked to verify the online data of the IAU meteor shower list. The activity periods for all meteor streams detected in CAMS data has been derived from the solar longitudes of the individual orbits that were associated with the meteor stream. For meteor showers that were absent in the CAMS data, mainly daylight meteor streams, CMOR data has been used to complete the information. To make future associations easier and to avoid mixing up shower data, the official naming and IAU code with the orbital elements are listed in this contribution.

  14. The orbit estimation for Larets satellite

    Science.gov (United States)

    Rutkowska, M.

    2006-10-01

    The LARETS satellite was launched on September 26, 2004 into a circular orbit at an altitude of 690 km and with an inclination of 98.2 degree. The aim of this study is the computation of the orbit of the satellite LARETS with the highest accuracy possible. The paper discusses the influence of the modelling of different physical effects on the motion of LARETS, in particular in terms of orbit quality. All computations are performed with the NASA program GEODYN II (Eddy et al.,1990).

  15. Elliptical Orbit ⇒ 1/r2 Force

    Science.gov (United States)

    Prentis, Jeffrey; Fulton, Bryan; Hesse, Carol; Mazzino, Laura

    2007-01-01

    Newton's proof of the connection between elliptical orbits and inverse-square forces ranks among the "top ten" calculations in the history of science. This time-honored calculation is a highlight in an upper-level mechanics course. It would be worthwhile if students in introductory physics could prove the relation elliptical orbit ⇒ 1/r2 force without having to rely on upper-level mathematics. We introduce a simple procedure—Newton's Recipe—that allows students to readily and accurately deduce the algebraic form of force laws from a geometric analysis of orbit shapes.

  16. Cycler orbit between Earth and Mars

    Science.gov (United States)

    Byrnes, Dennis V.; Longuski, James M.; Aldrin, Buzz

    1993-06-01

    A periodic orbit between Earth and Mars has been discovered that, after launch, permits a space vehicle to cycle back and forth between the planets with moderate maneuvers at irregular intervals. A Space Station placed in this cycler orbit could provide a safe haven from radiation and comfortable living quarters for astronauts en route to Earth or Mars. The orbit is largely maintained by gravity assist from Earth. Numerical results from multiconic optimization software are presented for a 15-year period from 1995 through 2010.

  17. The orbital evolution of binary galaxies

    Science.gov (United States)

    Chan, R.; Junqueira, S.

    2001-02-01

    We present the results of self-consistent numerical simulations performed to study the orbital circularization of binary galaxies. We have generalized a previous model (Junqueira & de Freitas Pacheco 1994) and confirmed partially their results. The orbital evolution of pairs of galaxies is faster when we consider interacting pairs with contacting ``live'' galaxy halos but the circularization time remains larger than the Hubble time. Besides, the time behavior of the orbits has changed in comparison with previous work because of tidal forces and dynamical friction acting on the halos.

  18. Dual RF Astrodynamic GPS Orbital Navigator Satellite

    Science.gov (United States)

    Kanipe, David B.; Provence, Robert Steve; Straube, Timothy M.; Reed, Helen; Bishop, Robert; Lightsey, Glenn

    2009-01-01

    Dual RF Astrodynamic GPS Orbital Navigator Satellite (DRAGONSat) will demonstrate autonomous rendezvous and docking (ARD) in low Earth orbit (LEO) and gather flight data with a global positioning system (GPS) receiver strictly designed for space applications. ARD is the capability of two independent spacecraft to rendezvous in orbit and dock without crew intervention. DRAGONSat consists of two picosatellites (one built by the University of Texas and one built by Texas A and M University) and the Space Shuttle Payload Launcher (SSPL); this project will ultimately demonstrate ARD in LEO.

  19. Machine vision for real time orbital operations

    Science.gov (United States)

    Vinz, Frank L.

    1988-01-01

    Machine vision for automation and robotic operation of Space Station era systems has the potential for increasing the efficiency of orbital servicing, repair, assembly and docking tasks. A machine vision research project is described in which a TV camera is used for inputing visual data to a computer so that image processing may be achieved for real time control of these orbital operations. A technique has resulted from this research which reduces computer memory requirements and greatly increases typical computational speed such that it has the potential for development into a real time orbital machine vision system. This technique is called AI BOSS (Analysis of Images by Box Scan and Syntax).

  20. How to recognize intruders in your niche

    DEFF Research Database (Denmark)

    Andersen, Hanne

    2006-01-01

    One important problem concerning incommensurability is how to explain that two theories which are incommensurable and therefore mutually untranslatable and incomparable in a strictly logical, point-by-point way are still competing. The two standard approaches have been to argue either that the te......One important problem concerning incommensurability is how to explain that two theories which are incommensurable and therefore mutually untranslatable and incomparable in a strictly logical, point-by-point way are still competing. The two standard approaches have been to argue either...... that the terms of incommensurable theories may share reference, or that incommensurable theories target roughly the same object domain as far as the world-in-itself is concerned. However, neither of these approaches to the problem pay due respect to the incommensurability thesis' insights. In this paper I shall...

  1. Improving Protection Agains Intruders Using Passive Sonar

    NARCIS (Netherlands)

    Fillinger, L.; Hunter, A.J.; Zampolli, M.; Clarijs, M.C.; Verolme, J.L.

    2011-01-01

    Divers and small vessels are increasingly recognized as a potential threat to high value assets. Harbour and waterside surveillance systems that are used to counter the threat of divers are usually based on active sonar, whose performance can be limited by reverberation in a harbour environment.

  2. Correlating Temporal Thumbprints for Tracing Intruders

    Directory of Open Access Journals (Sweden)

    Jianhua Yang

    2006-08-01

    Full Text Available The Design of TCP/IP protocol makes it difficult to reliably traceback to the original attackers if they obscure their identities by logging through a chain of multiple hosts. A thumbprint method based on connection content was proposed in 1995 to traceback attackers, but this method is limited to non-encrypted sessions. In this paper, we propose a thumbprint based on time intervals, T-thumbprint, to identify a connection. T-thumbprint is a sequence of time gaps between adjacent TCP 'Send' packets of an interactive terminal session. An algorithm is presented to correlate two T-thumbprints to see if they belong to the same connection chain. We also discuss how to use T-thumbprints to traceback an attacker on the Internet, and how to defeat at-tacker's manipulation. T-thumbprint has advantages of: (1 It can be applied to encrypt sessions; (2 It does not require tightly synchronized clocks; (3 It can defeat attacker's manipulation to some extent; and (4 It is efficient, can be used to trace attackers in real time.

  3. Orbits 2nd order singularity-free solutions

    CERN Document Server

    Xu, Guochang

    2014-01-01

    In its 2nd edition, this book covers the theory of satellite orbits, derives the complete solutions of orbital disturbances, describes the algorithms of orbits determination and the applications of the theory to the phenomenon of physical satellite formation.

  4. MR Imaging of Orbital Inflammatory Syndrome, Orbital Cellulitis, and Orbital Lymphoid Lesions: The Role of Diffusion-Weighted Imaging

    Science.gov (United States)

    Kapur, R.; Sepahdari, A.R.; Mafee, M.F.; Putterman, A.M.; Aakalu, V.; Wendel, L.J.A.; Setabutr, P.

    2013-01-01

    BACKGROUND AND PURPOSE Orbital inflammatory syndrome (OIS) has clinical features that overlap with orbital lymphoid lesions and orbital cellulitis. Prompt diagnosis is needed in all 3 conditions because the management of each one differs greatly. CT and MR imaging, though useful, do not always distinguish among these conditions. The aim of this study was to identify the role of diffusion-weighted imaging (DWI) in differentiating these 3 diagnoses. MATERIALS AND METHODS A retrospective analysis of orbital MR imaging was conducted. T1- and T2-weighted and postcontrast images were analyzed. Region-of-interest analysis was performed by using measurements in areas of abnormality seen on conventional MR imaging sequences and measurements of the ipsilateral thalamus for each patient. The DWI signal intensity of the lesion was expressed as a percentage of average thalamic intensity in each patient. Similarly, lesion apparent diffusion coefficients (ADCs) and lesion-thalamus ADC ratios were calculated. Statistical significance was determined by the Kruskal-Wallis test, and post hoc pairwise comparisons, by the Mann-Whitney U test for DWI-intensity ratio, ADC, and ADC ratio. RESULTS A significant difference was noted in DWI intensities, ADC, and ADC ratio between OIS, orbital lymphoid lesions, and orbital cellulitis (P cellulitis. Lymphoid lesions showed lower ADC than OIS and cellulitis. A trend was seen toward lower ADC in OIS than in cellulitis (P = .17). CONCLUSIONS DWI may help differentiate OIS from lymphoid lesions and cellulitis and may allow more rapid management. PMID:18842758

  5. A Case of Orbital Myiasis in Recurrent Eyelid Basal Cell Carcinoma Invasive into the Orbit.

    Science.gov (United States)

    Pandey, Triptesh Raj; Shrestha, Gulshan Bahadur; Sitaula, Ranju Kharel; Shah, Dev Narayan

    2016-01-01

    Introduction. Orbital myiasis is the infestation of the orbital tissues by fly larvae or maggots. Compromise of periorbital tissues by malignant disease, surgery, ischemia, or infection may predispose the patient to orbital myiasis. Case Report. A 73-year-old male patient with neglected recurrent basal cell carcinoma of the eyelid invasive into the orbit presented with complaints of intense itching and crawling sensation with maggots wriggling and falling from the wound of left orbit. The patient improved following manual removal of the maggots along with oral Ivermectin treatment. Recurrence of the basal cell carcinoma was confirmed by punch biopsy from the wound and extended exenteration of the orbit followed by reconstructive surgery was done. Conclusion. Orbital myiasis is a rare and preventable ocular morbidity that can complicate the malignancies resulting in widespread tissue destruction. The broad spectrum antiparasitic agent, Ivermectin, can be used as noninvasive means to treat orbital myiasis. In massive orbital myiasis and those associated with malignancies, exenteration of the orbit must be seriously considered.

  6. Thyroid Transcription Factor-1 in Orbital Adipose Tissues: Potential Role in Orbital Thyrotropin Receptor Expression

    Science.gov (United States)

    Bhattacharyya, Kalyan K.; Coenen, Michael J.; Bahn, Rebecca S.

    2005-01-01

    Thyroid transcription factor-1 (TTF-1) is required for maximal expression of thyrotropin receptor (TSHR) in the thyroid. Extrathyroidal TSHR expression is detectable in normal orbital adipose tissues, with increased levels found in orbital tissues from patients with Graves’ ophthalmopathy (GO), and in orbital preadipocyte cultures following differentiation. In order to determine whether TTF-1 might be involved in orbital TSHR expression, we used quantitative real-time polymerase chain reaction (PCR) to assess relative expression of this and other thyroid-associated transcription factors (TTF-2 and Pax-8) in GO orbital tissue specimens (n = 28) and cultures (n = 3), and in normal orbital tissues (n = 19) and cultures (n = 3). We detected TTF-1 and TTF-2 mRNA in GO and normal orbital tissue samples, with no difference in levels noted between the tissues. In the GO orbital cultures, TTF-1 mRNA was higher in differentiated than in control (undifferentiated) cultures (p < 0.05), while TTF-2 was unchanged. In the normal cultures, neither TTF-1 nor TTF-2 mRNA levels increased in differentiated cultures. Pax8 was undetectable in all orbital tissues and cell cultures. The presence of mRNA encoding TTF-1 in orbital tissues and cultures suggest that this transcription factor may play an important role in extrathyroidal, as it does in thyroidal, TSHR expression. PMID:15929662

  7. CD56 negative extranodal NK/T-cell lymphoma of the orbit mimicking orbital cellulitis.

    Science.gov (United States)

    Pine, Ryan R; Clark, Jeremy D; Sokol, Jason A

    2013-02-01

    To report a case of Extranodal NK/T-cell lymphoma of the orbit mimicking orbital cellulitis. A 52-year-old healthy male presented to our institution after 3 months of treatment for sinusitis with antibiotics and steroids. The patient was transferred due to the presence of an "orbital abscess" on CT with orbital signs that not responding to antibiotics. Clinical examination was significant for decreased vision in the affected orbit of 20/50, a trace RAPD OS, elevated IOP of 30 OS, proptosis and grossly decreased motility with diplopia, periorbital edema and chemosis. Dilated funded exam was unremarkable. CT imaging demonstrated a left sided pan-sinusitis, a medial "orbital process" with proptosis and erosion of the cribiform plate. The patient was taken for an emergent orbital exploration for histopathologic diagnosis. Intraorbital and sinus biopsy was consistent with extranodal NK/T-cell lymphoma, with extension into the skull base and left orbital space. The patient was started on radiation therapy followed by chemotherapy. The authors demonstrate how the acute presentation of an aggressive extranodal NK/T-cell lymphoma can present in a similar fashion as orbital cellulitis. Additionally, the case highlights that a unilateral pansinusitis with involvement of the skull base and orbit is likely due an aggressive malignant process in an immune competent patient.

  8. A Case of Orbital Myiasis in Recurrent Eyelid Basal Cell Carcinoma Invasive into the Orbit

    Directory of Open Access Journals (Sweden)

    Triptesh Raj Pandey

    2016-01-01

    Full Text Available Introduction. Orbital myiasis is the infestation of the orbital tissues by fly larvae or maggots. Compromise of periorbital tissues by malignant disease, surgery, ischemia, or infection may predispose the patient to orbital myiasis. Case Report. A 73-year-old male patient with neglected recurrent basal cell carcinoma of the eyelid invasive into the orbit presented with complaints of intense itching and crawling sensation with maggots wriggling and falling from the wound of left orbit. The patient improved following manual removal of the maggots along with oral Ivermectin treatment. Recurrence of the basal cell carcinoma was confirmed by punch biopsy from the wound and extended exenteration of the orbit followed by reconstructive surgery was done. Conclusion. Orbital myiasis is a rare and preventable ocular morbidity that can complicate the malignancies resulting in widespread tissue destruction. The broad spectrum antiparasitic agent, Ivermectin, can be used as noninvasive means to treat orbital myiasis. In massive orbital myiasis and those associated with malignancies, exenteration of the orbit must be seriously considered.

  9. Adapting ASPEN for Orbital Express

    Science.gov (United States)

    Chouinard, Caroline; Tran, Daniel; Jones, Grailing; Dang, Van; Knight, Russell

    2010-01-01

    By studying the Orbital Express mission, modeling the spacecraft and scenarios, and testing the system, a technique has been developed that uses recursive decomposition to represent procedural actions declaratively, schema-level uncertainty reasoning to make uncertainty reasoning tractable, and lightweight, natural language processing to automatically parse procedures to produce declarative models. Schema-level uncertainty reasoning has, at its core, the basic assumption that certain variables are uncertain, but not independent. Once any are known, then the others become known. This is important where a variable is uncertain for an action and many actions of the same type exist in the plan. For example, if the number of retries to purge pump lines was unknown (but bounded), and each attempt required a sub-plan, then, once the correct number of attempts required for a purge was known, it would likely be the same for all subsequent purges. This greatly reduces the space of plans that needs to be searched to ensure that all executions are feasible. To accommodate changing scenario procedures, each is ingested into a tabular format in temporal order, and a simple natural-language parser is used to read each step and to derive the impact of that step on memory, power, and communications. Then an ASPEN (Activity Scheduling and Planning Environment) model is produced based on this analysis. The model is tested and further changed by hand, if necessary, to reflect the actual procedure. This results in a great savings of time used for modeling procedures. Many processes that need to be modeled in ASPEN (a declarative system) are, in fact, procedural. ASPEN includes the ability to model activities in a hierarchical fashion, but this representation breaks down if there is a practically unbounded number of sub-activities and decomposition topologies. However, if recursive decomposition is allowed, HTN-like encodings are enabled to represent most procedural phenomena. For

  10. Spin-orbit excitations of quantum wells

    Science.gov (United States)

    Ambrosetti, A.; Escartín, J. M.; Lipparini, E.; Pederiva, F.

    2011-04-01

    Spin-orbit effects on the photoabsorption of a quantum well are discussed by means of a sum rules approach. We show that while the strength of the excitation is zero when the spin-orbit coupling is neglected, the inclusion of the spin-orbit interaction gives rise to a nonzero strength and mean excitation energy in the far-infrared region. A simple expression for these quantities up to the second order in the Rashba interaction is derived. Modifications of the results due to the Dresselhaus spin-orbit term are discussed. The effect of two-body Coulomb interaction is then studied by means of a Quantum Monte Carlo calculation, showing that electron-electron correlations induce only a small deviation from the independent particle model result.

  11. Circular Orbits Inside the Sphere of Death

    OpenAIRE

    McDonald, Kirk T.

    2000-01-01

    A wheel or sphere rolling without slipping on the inside of a sphere in a uniform gravitational field can have stable circular orbits that lie wholly above the "equator", while a particle sliding freely cannot.

  12. Cephalic Tetanus from Penetrating Orbital Wound

    Directory of Open Access Journals (Sweden)

    Eloïse Guyennet

    2009-01-01

    Full Text Available Tetanus is a neurologic disorder caused by tetanospasmin, a protein toxin elaborated by Clostridium tetani. Cephalic tetanus is a localized form of the disease causing trismus and dysfunction of cranial nerves. We report the case of a man who presented with facial trauma, complete ophthalmoplegia, exophthalmos, areactive mydriasis, and periorbital hematoma. An orbital CT revealed air bubbles in the right orbital apex. The patient was given a tetanus toxoid booster and antibiotherapy. After extraction of a wooden foreign body, the patient developed right facial nerve palsy, disorders of swallowing, contralateral III cranial nerve palsy, and trismus. Only one case of cephalic tetanus from penetrating orbital wound has been reported in literature 20 years ago. When a patient presents with an orbital wound with ophthalmoplegia and signs of anaerobic infection, cephalic tetanus should be ruled out.

  13. Efficient Trajectory Propagation for Orbit Determination Problems

    Science.gov (United States)

    Roa, Javier; Pelaez, Jesus

    2015-01-01

    Regularized formulations of orbital motion apply a series of techniques to improve the numerical integration of the orbit. Despite their advantages and potential applications little attention has been paid to the propagation of the partial derivatives of the corresponding set of elements or coordinates, required in many orbit-determination scenarios and optimization problems. This paper fills this gap by presenting the general procedure for integrating the state-transition matrix of the system together with the nominal trajectory using regularized formulations and different sets of elements. The main difficulty comes from introducing an independent variable different from time, because the solution needs to be synchronized. The correction of the time delay is treated from a generic perspective not focused on any particular formulation. The synchronization using time-elements is also discussed. Numerical examples include strongly-perturbed orbits in the Pluto system, motivated by the recent flyby of the New Horizons spacecraft, together with a geocentric flyby of the NEAR spacecraft.

  14. Synchronization behind the formation of Orbital Systems

    Science.gov (United States)

    Ruda, Jennifer; Abrams, Daniel

    2018-01-01

    This paper aims to gain a greater understanding of why planetary and galactic orbital systems form as either synchronous or asynchronous systems. We simulate the orbiting particles and their movements. We believe that it is possible Kuramoto's model for synchronization can be used to explain the behavior of the particles orbiting about the larger mass object. We believe that the difference between synchrony and asynchrony will be a function of parameters for the system. We examine the effect the parameters have on the order parameter, defined by the Kuramoto model. We additionally examine the simplest system, one with two orbiting particles. We see that there are equilibrium points, indicating the possibility of both synchrony and asynchrony, depending on the system parameters. Our results merit further investigation into the equilibrium of the system with a large number of particles.

  15. Blindness resulting from orbital cellulitis following rhinoplasty.

    Science.gov (United States)

    Lee, Kyung Mook; Han, Sang Chul; Ho, Samuel Y M; Kim, Jeong Tae; Kim, Youn Hwan

    2013-05-01

    Ophthalmic complications occurring after non-ophthalmic surgery are rare. We present a case of orbital cellulitis in a 24-year-old woman, who had undergone augmentation rhinoplasty in combination with breast augmentation. Symptoms included pain, swelling, erythema and eventual loss of vision in the left eye. Intravenous administration of antibiotics did not halt the rapid progression of this infection. On the sixth postoperative day, the patient underwent left-orbital evisceration to prevent the spread of infection to other organ systems. Despite aggressive therapy, the sequela was permanent, unilateral blindness. Orbital cellulitis in aesthetic surgery is extremely rare. In patients undergoing rhinoplasties that may be prolonged due to other concomitant cosmetic procedures, aseptic preoperative preparation and careful monitoring for signs of orbital infection are recommended. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  16. ORION: A Supersynchronous Transfer Orbit mission

    Science.gov (United States)

    Walters, I. M.; Baker, J. F.; Shurmer, I. M.

    1995-01-01

    ORION F1 was launched on 29th November 1994 on an Atlas IIA launch vehicle. It was designed, built and delivered in-orbit by Matra Marconi Space Systems Plc and was handed over to ORION Satellite Corporation on 20th January 1995 at its on-station longitude of 37.5 deg W. The mission differed significantly from that of any other geostationary communications satellite in that the Transfer Orbit apogee altitude of 123,507 km was over three times geosynchronous (GEO) altitude and one third of the way to the moon. The SuperSynchronous Transfer Orbit (SSTO) mission is significantly different from the standard Geostationary Transfer Orbit (GTO)mission in a number of ways. This paper discusses the essential features of the mission design through its evolution since 1987 and the details of the highly successful mission itself including a detailed account of the attitude determination achieved using the Galileo Earth and Sun Sensor (ESS).

  17. ORION: A Supersynchronous Transfer Orbit mission

    Science.gov (United States)

    Walters, I. M.; Baker, J. F.; Shurmer, I. M.

    1995-05-01

    ORION F1 was launched on 29th November 1994 on an Atlas IIA launch vehicle. It was designed, built and delivered in-orbit by Matra Marconi Space Systems Plc and was handed over to ORION Satellite Corporation on 20th January 1995 at its on-station longitude of 37.5 deg W. The mission differed significantly from that of any other geostationary communications satellite in that the Transfer Orbit apogee altitude of 123,507 km was over three times geosynchronous (GEO) altitude and one third of the way to the moon. The SuperSynchronous Transfer Orbit (SSTO) mission is significantly different from the standard Geostationary Transfer Orbit (GTO)mission in a number of ways. This paper discusses the essential features of the mission design through its evolution since 1987 and the details of the highly successful mission itself including a detailed account of the attitude determination achieved using the Galileo Earth and Sun Sensor (ESS).

  18. Orbital impacts and the space shuttle windshield

    Science.gov (United States)

    Edelstein, Karen S.

    1995-06-01

    The Space Transportation System (STS) fleet has flown more than sixty missions over the fourteen years since its first flight. As a result of encounters with on-orbit particulates (space debris and micrometeoroids), 177 impact features (chips) have been found on the STS outer windows (through STS-65). Forty-five of the damages were large enough to warrant replacement of the window. NASA's orbital operations and vehicle inspection procedures have chnaged over the history of the shuttle program, in response to concerns about the orbital environment and the cost of maintaining the space shuttle. These programmatic issues will be discussed, including safety concerns, maintenance issues, inspection procedures, and flight rule changes. Examples of orbital debris impacts to the shuttle windows will be provided. There will also be a brief discussion of the impact properties of glass and what design changes have been considered to improve the impact properties of the windows.

  19. NEAR GRS SPECTRA FOR EROS ORBIT PHASE

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Gamma Ray Spectrometer (GRS) observations made during the Eros orbit phase of the NEAR mission. The individual observations are combined into...

  20. Polar-Orbiting Satellite (POES) Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visible and Infrared satellite imagery taken from camera systems or radiometer instruments on satellites in orbit around the poles. Satellite campaigns include...

  1. Satellite orbits in Levi-Civita space

    Science.gov (United States)

    Humi, Mayer

    2018-03-01

    In this paper we consider satellite orbits in central force field with quadratic drag using two formalisms. The first using polar coordinates in which the satellite angular momentum plays a dominant role. The second is in Levi-Civita coordinates in which the energy plays a central role. We then merge these two formalisms by introducing polar coordinates in Levi-Civita space and derive a new equation for satellite orbits which unifies these two paradigms. In this equation energy and angular momentum appear on equal footing and thus characterize the orbit by its two invariants. Using this formalism we show that equatorial orbits around oblate spheroids can be expressed analytically in terms of Elliptic functions. In the second part of the paper we derive in Levi-Civita coordinates a linearized equation for the relative motion of two spacecrafts whose trajectories are in the same plane. We carry out also a numerical verification of these equations.

  2. Orbit Response Measurements at the SPS

    CERN Document Server

    Wenninger, J

    2004-01-01

    The optics of the SPS ring and the TT40 transfer line have been analyzed using the closed orbit (respectively trajectory) response to controlled corrector magnet deflections. A large amount of information on the machine model, beam position monitor quality and orbit corrector calibrations can be extracted from te response data. The data was analyzed with the LOCO fit program that was adapted to the SPS machine model. A large amount of data was collected on the SPS ring, and the modelling was tested under a number of different conditions. The SPS ring data showed that a significant number of horizontal SPS orbit correctors do not provide the nominal kick strength and are damaged at the level of the magnet coil. This note describes the experience that has been gained at the SPS, the information that could be extracted from orbit data and some of the limitations of the analysis procedure in the context of the SPS.

  3. Graph-based Methods for Orbit Classification

    Energy Technology Data Exchange (ETDEWEB)

    Bagherjeiran, A; Kamath, C

    2005-09-29

    An important step in the quest for low-cost fusion power is the ability to perform and analyze experiments in prototype fusion reactors. One of the tasks in the analysis of experimental data is the classification of orbits in Poincare plots. These plots are generated by the particles in a fusion reactor as they move within the toroidal device. In this paper, we describe the use of graph-based methods to extract features from orbits. These features are then used to classify the orbits into several categories. Our results show that existing machine learning algorithms are successful in classifying orbits with few points, a situation which can arise in data from experiments.

  4. Designing the Orbital Space Tourism Experience

    Science.gov (United States)

    Webber, Derek

    2006-01-01

    Sub-orbital space tourism is now well on its way to becoming a reality, with offerings by Virgin Galactic, Rocketplane, and others soon to be made available. Orbital space tourism is harder to achieve, but, if successful as a business model, will make significant contributions towards improved operational efficiencies, reusability, reliability and economies of scale to the world of crewed space flight. Some responses to the President's Vision for Space Exploration have included public space travel in low Earth orbit as sustaining and enabling elements of the vision in a post-Shuttle space architecture. This paper addresses the steps necessary to make possible such a US-based orbital space tourism business, and will assist commercial and government agencies concerned with the development of this new sector.

  5. Transfer and capture into distant retrograde orbits

    Science.gov (United States)

    Scott, Christopher J.

    This dissertation utilizes theory and techniques derived from the fields of dynamical systems theory, astrodyanamics, celestial mechanics, and fluid mechanics to analyze the phenomenon of satellite capture and interrelated spacecraft transfers in restricted three-body systems. The results extend current knowledge and understanding of capture dynamics in the context of astrodynamics and celestial mechanics. Manifold theory, fast Lyapunov indicator maps, and the classification of space structure facilitate an analysis of the transport of objects from the chaotic reaches of the solar system to the distant retrograde region in the sun-Jupiter system. Apart from past studies this dissertation considers the role of the complex lobe structure encompassing stable regions in the circular restricted three-body problem. These structures are shown to be responsible for the phenomenon of sticky orbits and the transport of objects among stable regions. Since permanent capture can only be achieved through a change in energy, fast Lyapunov indicator maps and other methods which reveal the structure of the conservative system are used to discern capture regions and identify the underpinnings of the dynamics. Fast Lyapunov indicator maps provide an accurate classification of orbits of permanent capture and escape, yet monopolize computational resources. In anticipation of a fully three-dimensional analysis in the dissipative system a new mapping parameter is introduced based on energy degradation and averaged velocity. Although the study specifically addresses the sun-Jupiter system, the qualitative results and devised techniques can be applied throughout the solar system and to capture about extrasolar planets. Extending the analysis beyond the exterior of the stable distant retrograde region fosters the construction of transfer orbits from low-Earth orbit to a stable periodic orbit at the center of the stable distant retrograde region. Key to this analysis is the predictability of

  6. Satellite Laser Ranging Satellite Orbit Product from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — SLR Satellite Orbit solutions available from the Crustal Dynamics Data Information System (CDDIS). Precise Orbit Determination (POD) solutions in Standard Product 3...

  7. Introduction to orbital flight planning (1)

    Science.gov (United States)

    Blackwell, H. E. (Editor); Davis, E. L.; Dell, D. D.

    1981-01-01

    This workbook is designed for students interested in space flight planning, who after training, may serve as flight planning aides. Routine flight planning activities requiring engineering-type calculations and analysis are covered. Practice exercises and brief instructions are given for the programming and use of the hand calculator as well as the calculation of position and velocity in the orbital plane. Calculation of relative orbital position is also covered with emphasis upon celestial coordinates and time measurement.

  8. Orbital involvement in chronic lymphocytic leukemia.

    Science.gov (United States)

    Skinnider, L F; Romanchuk, K G

    1984-04-01

    In a 68-year-old man with chronic lymphocytic leukemia diagnosed on the basis of peripheral lymphocytosis, marked bilateral exophthalmos developed owing to massive orbital involvement by the disease. At the time there was no lymphadenopathy or evidence of organ infiltration. The response to radiotherapy was excellent. Orbital involvement is rare as an early clinical feature of chronic lymphocytic leukemia but should be considered in the differential diagnosis of bilateral exophthalmos in adults.

  9. Management of Orbital Floor Fractures: Our Experience

    Directory of Open Access Journals (Sweden)

    Biplab Deb

    2014-12-01

    Full Text Available Abstract Otolaryngologists are often called to evaluate and manage patients with orbital floor fracture. We have described an overview of the treatment of orbital floor fractures using different reconstructive materials viz. autogenous like bone graft from iliac crest and allogenous like silicon block and titanium mesh. We have found that different implant materials offers equivalent satisfactory results in both functional and aesthetic considerations.

  10. Cephalic Tetanus from Penetrating Orbital Wound

    OpenAIRE

    Eloïse Guyennet; Jean-Laurent Guyomard; Emilie Barnay; Franck Jegoux; Jean-François Charlin

    2009-01-01

    Tetanus is a neurologic disorder caused by tetanospasmin, a protein toxin elaborated by Clostridium tetani. Cephalic tetanus is a localized form of the disease causing trismus and dysfunction of cranial nerves. We report the case of a man who presented with facial trauma, complete ophthalmoplegia, exophthalmos, areactive mydriasis, and periorbital hematoma. An orbital CT revealed air bubbles in the right orbital apex. The patient was given a tetanus toxoid booster and antibiotherapy. After ex...

  11. Distinguishing features of preseptal and orbital cellulitis.

    Science.gov (United States)

    Bethel, James

    2010-03-01

    The differential diagnosis between orbital cellulitis and preseptal cellulitis is important as is the need to differentiate between an allergic response or infectious cellulitis of the eye. This article will examine the case of a 15-month-old boy who was brought to an emergency department with an oedematous right eye. The research about diagnosis and treatment will be evaluated and orbital cellulitis will be explored in more detail including the symptoms and complications.

  12. Necrotic intraocular retinoblastoma associated with orbital cellulitis.

    Science.gov (United States)

    Nalcı, Hilal; Gündüz, Kaan; Erden, Esra

    Orbital cellulitis associated with retinoblastoma is uncommon and is characterized by noninfectious inflammation of the periorbital structures. The underlying mechanism is thought to be necrosis of the intraocular tumor, leading to intraocular and periorbital inflammation. We report 2 retinoblastoma patients who presented with an orbital cellulitis-like picture and discuss clinical characteristics, histopathologic features, and treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Presentation and management of pediatric orbital cellulitis.

    Science.gov (United States)

    Fanella, Sergio; Singer, Alex; Embree, Joanne

    2011-01-01

    Orbital cellulitis is a serious, vision-threatening infection. To review the epidemiology and clinical data of pediatric orbital cellulitis in Manitoba. A 12-year retrospective review was conducted of all children (younger than 18 years of age) with orbital cellulitis admitted to Manitoba's only tertiary pediatric centre. Admission rates for orbital cellulitis were compared over three distinct time periods, based on licensure and funding levels of the heptavalent pneumococcal conjugate vaccine (PCV7) in Manitoba. Thirty-eight patients with orbital cellulitis were identified. Of these, 11% were of Aboriginal ethnicity in contrast with 30% to 40% of children who were admitted for other respiratory illnesses. Subperiosteal abscesses occurred in 31.5%. Only eight patients (21%) required surgery. Follow-up imaging after presentation usually did not indicate a need for subsequent surgical drainage. The mean number of orbital cellulitis cases per 1000 admissions for the following periods - before PCV7 licensure, after licensure and before full provincial funding, and after licensure and full funding - were 0.39, 0.53 and 0.90, respectively. No significant difference was noted among any of the periods as PCV7 coverage increased. The rate of subperiosteal abscesses was lower than other reports. This may be due to the median age at presentation. In contrast to admissions for most other respiratory infections at the Winnipeg Children's Hospital (Winnipeg, Manitoba), Aboriginal ethnicity was uncommon. Surprisingly, rates of admissions for orbital cellulitis appeared to show an increasing trend with increasing access to PCV7 in Manitoba, although overall the number of cases was very small. Studies into the changing microbiology of orbital cellulitis and sinusitis are warranted.

  14. An unusual organism causing orbital cellulitis.

    Science.gov (United States)

    Schwartz, H; Baskin, M A; Ilkiw, A; LeBeau, L

    1979-01-01

    Bacterial orbital cellulitis is a feared complication of paranasal sinus infection. Staphylococcus and Streptococcus species are the commoner pathogens involved in these cases. However, anaerobic bacteria and unusual Gram-negative organisms should be suspected as well. We treated a case of bacterial orbital cellulitis due to foci of infected paranasal sinuses caused by Eikenella corrodens, a Gram-negative rod. The patient was managed with intensive antibiotic coverage and surgical intervention. Images PMID:389281

  15. A case of odontogenic orbital cellulitis causing blindness by severe tension orbit.

    Science.gov (United States)

    Park, Chang Hyun; Jee, Dong Hyun; La, Tae Yoon

    2013-02-01

    We report a very rare case of odontogenic orbital cellulitis causing blindness by severe tension orbit. A 41-yr old male patient had visited the hospital due to severe periorbital swelling and nasal stuffiness while he was treated for a periodontal abscess. He was diagnosed with odontogenic sinusitis and orbital cellulitis, and treated with antibiotics. The symptoms were aggravated and emergency sinus drainage was performed. On the next day, a sudden decrease in vision occurred with findings of ischemic optic neuropathy and central retinal artery occlusion. Deformation of the eyeball posterior pole into a cone shape was found from the orbital CT. A high-dose steroid was administered immediately resulting in improvements of periorbital swelling, but the patient's vision had not recovered. Odontogenic orbital cellulitis is relatively rare, but can cause blindness via rapidly progressing tension orbit. Therefore even the simplest of dental problems requires careful attention.

  16. Orbit Feedback Operation with RCBX (MD 1209)

    CERN Document Server

    Wenninger, Jorg; Nisbet, David; Ponce, Laurette; Louro Alves, Diogo Miguel; CERN. Geneva. ATS Department

    2017-01-01

    The LHC Orbit Feedback (OFB) is able to drive any orbit corrector circuit (COD) to steer the LHC orbit. But during the first feedback tests in 2010, all attempts to use the common triplet orbit correctors (MCBX) failed because the QPS system installed to protect those magnets triggered power aborts as soon as the OFB steered the beam with those CODs. The reason was most likely the violation of the RCBX circuit acceleration limits. For this reason the MCBX orbit correctors were never driven by the OFB in regular operation. Although the performance of the OFB is generally excellent, the quality of the beam steering around IRs could be improved if the OFB could correct the orbit with the MCBX to counteract locally triplet quadrupole movements. The aim of this MD was to make a new attempt to use the MCBX in the OFB. The test was successful at injection (no circuit trip) and failed during the ramp (QPS power abort). The PC voltages and QPS Ures signals revealed the presence of voltage spikes with a period of 10~s...

  17. Superluminal periodic orbits in the Lorenz system

    Science.gov (United States)

    Algaba, A.; Merino, M.; Rodríguez-Luis, A. J.

    2016-10-01

    In this work we present, for the Lorenz system, analytical and numerical results on the existence of periodic orbits with unbounded amplitude and whose period tends to zero. Since a particle moving on these periodic orbits would be faster-than-light, we call them superluminal periodic orbits. To achieve this goal, we first find analytical expressions for the period in three different situations, where Hopf and Takens-Bogdanov bifurcations of infinite codimension occur. Thus, taking limit in the corresponding expressions allows to demonstrate the existence of superluminal periodic orbits for finite values of the parameter ρ (in a region where the other two parameters σ and b are negative). Moreover, we numerically show, in other two different cases of physical interest, that these orbits also exist when the parameter ρ tends to infinity. Finally, the presence of superluminal periodic orbits in the widely studied Chen and Lü systems follows directly from our results, taking into account that they are, generically, particular cases of the Lorenz system, as can be proved with a linear scaling in time and state variables.

  18. [Management of nasal orbital cellulitis in children].

    Science.gov (United States)

    Pan, Hongguang; Li, Lan; Zhong, Hui; Wu, Zebin; Zhang, Delun

    2015-01-01

    To analyze the clinical characteristics, diagnostic and treatment principle of orbital cellulitis in children, and to improve the experience of antibiotic treatment in orbital cellulites. Twenty children were admitted to Shenzhen Children's Hospital with the diagnosis of nasal orbital cellulitis between January 2009 and December 2013. The children were severe enough to warrant hospital admission. There were 13(65%) males and 7 (35%) females. The median age was 3.5 years (2 months to 7.2 years). The relationship between the serum C-reactive protein (CRP), white blood cell count and the hospitalization days were analyzed. The children were divided into 2 groups: Cefoperazone Sodium and Sulbactam Sodium for injection group and other antibiotic treatment group, the difference was compared. Statistical calculation was performed using SPSS 13.0 software. The serum CRP [(29.8 ± 22.0) mg/L] at the time of admission had a positive correlation with the time of hospitalization[ (6.3 ± 4.1) d, r = 0.46, P orbital cellulitis will be shorter and the orbital abscess can be prevented. Cefoperazone sulbactam and Sulbactam Sodium for injection is effective in treating pediatric orbital cellulitis.

  19. EIVAN - AN INTERACTIVE ORBITAL TRAJECTORY PLANNING TOOL

    Science.gov (United States)

    Brody, A. R.

    1994-01-01

    The Interactive Orbital Trajectory planning Tool, EIVAN, is a forward looking interactive orbit trajectory plotting tool for use with Proximity Operations (operations occurring within a one kilometer sphere of the space station) and other maneuvers. The result of vehicle burns on-orbit is very difficult to anticipate because of non-linearities in the equations of motion governing orbiting bodies. EIVAN was developed to plot resulting trajectories, to provide a better comprehension of orbital mechanics effects, and to help the user develop heuristics for onorbit mission planning. EIVAN comprises a worksheet and a chart from Microsoft Excel on a Macintosh computer. The orbital path for a user-specified time interval is plotted given operator burn inputs. Fuel use is also calculated. After the thrust parameters (magnitude, direction, and time) are input, EIVAN plots the resulting trajectory. Up to five burns may be inserted at any time in the mission. Twenty data points are plotted for each burn and the time interval can be varied to accommodate any desired time frame or degree of resolution. Since the number of data points for each burn is constant, the mission duration can be increased or decreased by increasing or decreasing the time interval. The EIVAN program runs with Microsoft's Excel for execution on a Macintosh running Macintosh OS. A working knowledge of Excel is helpful, but not imperative, for interacting with EIVAN. The program was developed in 1989.

  20. Bilateral orbital complications of paediatric rhinosinusitis.

    Science.gov (United States)

    Singh, S K; James, E; Sabarigirish, K; Swami, H; Sood, Tarun

    2014-01-01

    The spread of infection from the ethmoid sinuses to the orbit occurs directly through a congenital dehiscence of the lamina papyracea or via haematogenous spread through ophthalmic venous system. Hence orbital complications of paediatric rhinosinusitis are usually unilateral at presentation. We describe three children with bilateral orbital cellulitis that occurred as a complication of rhinosinusitis without intracranial spread of the infection. The children ranged in the age group from 4 to 7 years. All these children had a prolonged hospital stay from 14 to 25 days and underwent multiple surgical procedures to drain the subperiosteal abscess. These children presented to the hospital with bilateral orbital cellulitis without significant past history. All of them on radiological evaluation showed subperiosteal abscess involving only one orbit. They were taken up for functional endoscopic sinus surgery and the subperiosteal abscess was drained endoscopically with partial removal of lamina papyracea. One case required second surgery despite good recovery for two days post first surgery. Two cases had severe unilateral visual loss at presentation but both recovered dramatically after the surgery. All cases had uneventful recovery with no residual disability. The purpose of this article is to discuss the reasons for bilateral orbital complications of rhinosinusitis at initial presentation despite the previous hypothesis of unilateral involvement.

  1. Orbit error characteristic and distribution of TLE using CHAMP orbit data

    Science.gov (United States)

    Xu, Xiao-li; Xiong, Yong-qing

    2018-02-01

    Space object orbital covariance data is required for collision risk assessments, but publicly accessible two line element (TLE) data does not provide orbital error information. This paper compared historical TLE data and GPS precision ephemerides of CHAMP to assess TLE orbit accuracy from 2002 to 2008, inclusive. TLE error spatial variations with longitude and latitude were calculated to analyze error characteristics and distribution. The results indicate that TLE orbit data are systematically biased from the limited SGP4 model. The biases can reach the level of kilometers, and the sign and magnitude are correlate significantly with longitude.

  2. Rehabilitation of orbital defect with silicone orbital prosthesis retained by dental implants

    Directory of Open Access Journals (Sweden)

    Satyabodh Shesharaj Guttal

    2016-01-01

    Full Text Available Orbital defects can result from cancer, birth anomalies, or trauma leading to an onslaught of problems in the function and psyche of the patient. These defects are restored by surgical reconstruction and followed by placement of orbital prosthesis for cosmetic makeup. The use of dental implants in retaining orbital prosthesis improves patient acceptance of the prosthesis owing to better retention and stability than conventional adhesive retained prosthesis. This case report describes a custom-made magnetic retentive assembly anchored by a dental implant which offers the orbital prosthesis the simplicity of self-alignment and ease of use.

  3. Rehabilitation of orbital defect with silicone orbital prosthesis retained by dental implants.

    Science.gov (United States)

    Guttal, Satyabodh Shesharaj; Desai, Jhanvi; Kudva, Adarsh; Patil, Basavaraj R

    2016-01-01

    Orbital defects can result from cancer, birth anomalies, or trauma leading to an onslaught of problems in the function and psyche of the patient. These defects are restored by surgical reconstruction and followed by placement of orbital prosthesis for cosmetic makeup. The use of dental implants in retaining orbital prosthesis improves patient acceptance of the prosthesis owing to better retention and stability than conventional adhesive retained prosthesis. This case report describes a custom-made magnetic retentive assembly anchored by a dental implant which offers the orbital prosthesis the simplicity of self-alignment and ease of use.

  4. Orbital reconstruction: prefabricated implants, data transfer, and revision surgery.

    Science.gov (United States)

    Bittermann, Gido; Metzger, Marc Christian; Schlager, Stefan; Lagrèze, Wolf Alexander; Gross, Nikolai; Cornelius, Carl-Peter; Schmelzeisen, Rainer

    2014-10-01

    External impact to the orbit may cause a blowout or zygomatico-maxillary fractures. Diagnosis and treatment of orbital wall fractures are based on both physical examination and computed tomography scan of the orbit. Injuries of the orbit often require a reconstruction of its orbital walls. Using computer-assisted techniques, anatomically preformed orbital implants, and intraoperative imaging offers precise and predictable results of orbital reconstructions. Secondary reconstruction of the orbital cavity is challenging due to fractures healed in malposition, defects, scarring, and lack of anatomic landmarks, and should be avoided by precise primary reconstruction. The development of preformed orbital implants based on topographical analysis of the orbital cavity was a milestone for the improvement of primary orbital reconstruction. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  5. Maintaining Aura's Orbit Requirements While Performing Orbit Maintenance Maneuvers Containing an Orbit Normal Delta-V Component

    Science.gov (United States)

    Johnson, Megan R.; Petersen, Jeremy D.

    2014-01-01

    The Earth Observing System (EOS) Afternoon Constellation consists of five member missions (GCOM-W1, Aqua, CALIPSO, CloudSat, and Aura), each of which maintain a frozen, sun-synchronous orbit with a 16-day repeating ground track that follows the Worldwide Reference System-2 (WRS-2). Under nominal science operations for Aura, the propulsion system is oriented such that the resultant thrust vector is aligned 13.493 degrees away from the velocity vector along the yaw axis. When performing orbit maintenance maneuvers, the spacecraft performs a yaw slew to align the thrust vector in the appropriate direction. A new Drag Make Up (DMU) maneuver operations scheme has been implemented for Aura alleviating the need for the 13.493 degree yaw slew. The focus of this investigation is to assess the impact that no-slew DMU maneuver operations will have on Aura's Mean Local Time (MLT) which drives the required along track separation between Aura and the constellation members, as well as Aura's frozen orbit properties, eccentricity and argument of perigee. Seven maneuver strategies were analyzed to determine the best operational approach. A mirror pole strategy, with maneuvers alternating at the North and South poles, was implemented operationally to minimize impact to the MLT. Additional analysis determined that the mirror pole strategy could be further modified to include frozen orbit maneuvers and thus maintain both MLT and the frozen orbit properties under noslew operations.

  6. Orbital invasion by periocular basal cell carcinoma.

    Science.gov (United States)

    Leibovitch, Igal; McNab, Alan; Sullivan, Timothy; Davis, Garry; Selva, Dinesh

    2005-04-01

    To present a large series of patients with orbital invasion by periocular basal cell carcinoma (BCC). Retrospective, noncomparative, interventional case series. All cases diagnosed with orbital invasion by periocular BCC between January 1985 and July 2004 in 3 Orbital Units in Australia. The clinical records of all patients were reviewed. Patients' demographics, clinical presentation, histologic subtypes, treatment modalities, recurrence rate, and tumor-related death. There were 64 patients (49 males) with a mean age of 70+/-13 years. Most tumors (84.4%) were recurrent or previously incompletely excised, and the medial canthus was most frequently involved (56.2%). Signs suggestive of orbital involvement included a mass with bone fixation (35.7%), limitation of ocular motility (30.4%), and globe displacement (17.6%). There were no signs suggestive of orbital invasion in 35.7%. Most patients (51.6%) had infiltrative histologic findings, and perineural invasion was present in 19.3%. Treatment modalities were mainly exenteration alone or combined with radiotherapy. During a mean follow-up period of 3.6 years, 3 cases of recurrence (4.7%) were diagnosed. Only 1 patient (1.6%) died from tumor-related causes. Orbital invasion by periocular BCC is an uncommon event that may be associated with significant ocular morbidity and, rarely, death. Because orbital invasion may often be clinically silent, clinicians need to be alert to the possibility in high-risk tumors and consider appropriate imaging. Surgical treatment with exenteration or excision, with or without radiotherapy, results in a low recurrence and mortality rate.

  7. Risk factors of preseptal and orbital cellulitis.

    Science.gov (United States)

    Babar, Tariq Farooq; Zaman, Mir; Khan, Mohammad Naeem; Khan, Mohammad Daud

    2009-01-01

    To estimate the frequency and major risk factors of preseptal and orbital cellulitis. A cross-sectional analytical study. The Khyber Institute of Ophthalmic Medical Sciences, Hayatabad Medical Complex, Peshawar from July 2003 to December 2006. All consecutive patients between ages 6 and 40 years, admitted to the institute with the diagnosis of preseptal and orbital cellulitis were included in the study. The patients were divided into two groups. Group I included patients with ages 6-16 years and group II with ages 17-40 years. The clinical features, diagnosis and risk factors were entered on a specially-designed proforma. The risk factors included were trauma, insect bite, localized or systemic infection and postsurgical. Odd ratio and p-values were calculated for potential risk factors. The frequency of orbital cellulitis was 0.1% of total admission. Out of 26 patients, 42.30% patients were in group I and 57 in group II. In group I, insect bite was the most common risk factor identified in 40% of patients with preseptal cellulitis and trauma as a common cause in 50% with orbital cellulitis. In group II, trauma was the leading cause in 50% of patients with preseptal cellulitis and sinusitis as a common cause in 18.1% with those of orbital cellulitis. In both groups the p-values were found insignificant (p>0.5). Complications included cicatricial ectropion in 44.4% and orbital abscess in 41.1%. For preseptal cellulitis, insect bite was the most common cause in group I and trauma was the leading cause in group II. For orbital cellulitis, trauma was important cause in group I and sinusitis in group II.

  8. Photometric Studies of Orbital Debris at GEO

    Science.gov (United States)

    Seitzer, Patrick; Abercromby, Kira J.; Rodriguez-Cowardin, Heather M.; Barker, Ed; Foreman, Gary; Horstman, Matt

    2009-01-01

    We report on optical observations of debris at geosynchronous Earth orbit (GEO) using two telescopes simultaneously at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. The University of Michigan s 0.6/0.9-m Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope) was used in survey mode to find objects that potentially could be at GEO. Because GEO objects only appear in this telescope s field of view for an average of 5 minutes, a full six-parameter orbit can not be determined. Interrupting the survey for follow-up observations leads to incompleteness in the survey results. Instead, as objects are detected with MODEST, initial predictions assuming a circular orbit are done for where the object will be for the next hour, and the objects are reacquired as quickly as possible on the CTIO 0.9-m telescope. This second telescope follows-up during the first night and, if possible, over several more nights to obtain the maximum time arc possible, and the best six parameter orbit. Our goal is to obtain an initial orbit and calibrated colors for all detected objects fainter than R = 15th in order to estimate the orbital distribution of objects selected on the basis of two observational criteria: magnitude and angular rate. One objective is to estimate what fraction of objects selected on the basis of angular rate are not at GEO. A second objective is to obtain magnitudes and colors in standard astronomical filters (BVRI) for comparison with reflectance spectra of likely spacecraft materials.

  9. Management of Orbital and Periorbital Venous Malformation

    Directory of Open Access Journals (Sweden)

    Lara A. Benoiton

    2017-05-01

    Full Text Available BackgroundTo review our management of common venous malformation (VM affecting the orbit and/or periorbital area.MethodsConsecutive patients with orbital and/or periorbital VM were identified from our vascular anomalies database. Demographic details of the patients, anatomic site(s affected, symptoms and signs, presence of a family history of VM, and types of treatment(s were collected, supplemented by chart review.ResultsA total of 24 patients’ age 1–68 (mean, 30 years with orbital and/or periorbital VM presented with cosmetic concerns (n = 17, 71%, distensibility (n = 15, 63%, pain (n = 9, 38%, diplopia (n = 4, 17%, and spontaneous thrombosis (n = 1, 8%. The VM caused globe dystopia (n = 13, 54%, enophthalmos (n = 6, 25%, proptosis (n = 3, 12%, exotropia (n = 3, 12%, and pseudoptosis with visual obstruction (n = 3, 13%. A total of 11 (46% patients were managed conservatively. 13 (54% patients underwent active treatment. Ethanol sclerotherapy (ES was performed in six patients with extensive facial VM associated with orbital/periorbital involvement, resulting in symptomatic improvement in five patients, one of whom developed skin necrosis and another patient developed reduced infraorbital nerve sensation. Surgery was performed for localized lesion (n = 3, 23%, for extensive lesions (n = 4, 31% and as an adjunct to ES (n = 6, 46% resulting in symptomatic improvement in all patients. One patient required correction of lower lid ectropion.ConclusionOrbital and/or periorbital VMs are heterogeneous, and management needs to be individualized. Surgery is used for localized lesions aiming for complete excision, as a debulking procedure for extensive orbital/periorbital VM when ES was not possible, or following ES for extensive facial VM with orbital and/or periorbital involvement.

  10. Linked Autonomous Interplanetary Satellite Orbit Navigation

    Science.gov (United States)

    Parker, Jeffrey S.; Anderson, Rodney L.; Born, George H.; Leonard, Jason M.; McGranaghan, Ryan M.; Fujimoto, Kohei

    2013-01-01

    A navigation technology known as LiAISON (Linked Autonomous Interplanetary Satellite Orbit Navigation) has been known to produce very impressive navigation results for scenarios involving two or more cooperative satellites near the Moon, such that at least one satellite must be in an orbit significantly perturbed by the Earth, such as a lunar halo orbit. The two (or more) satellites track each other using satellite-to-satellite range and/or range-rate measurements. These relative measurements yield absolute orbit navigation when one of the satellites is in a lunar halo orbit, or the like. The geometry between a lunar halo orbiter and a GEO satellite continuously changes, which dramatically improves the information content of a satellite-to-satellite tracking signal. The geometrical variations include significant out-of-plane shifts, as well as inplane shifts. Further, the GEO satellite is almost continuously in view of a lunar halo orbiter. High-fidelity simulations demonstrate that LiAISON technology improves the navigation of GEO orbiters by an order of magnitude, relative to standard ground tracking. If a GEO satellite is navigated using LiAISON- only tracking measurements, its position is typically known to better than 10 meters. If LiAISON measurements are combined with simple radiometric ground observations, then the satellite s position is typically known to better than 3 meters, which is substantially better than the current state of GEO navigation. There are two features of LiAISON that are novel and advantageous compared with conventional satellite navigation. First, ordinary satellite-to-satellite tracking data only provides relative navigation of each satellite. The novelty is the placement of one navigation satellite in an orbit that is significantly perturbed by both the Earth and the Moon. A navigation satellite can track other satellites elsewhere in the Earth-Moon system and acquire knowledge about both satellites absolute positions and velocities

  11. Validation of GNSS orbits using SLR observations

    Science.gov (United States)

    Urschl, C.; Gurtner, W.; Hugentobler, U.; Schaer, S.; Beutler, G.

    Satellite Laser Ranging (SLR) observations allow for a completely independent validation of orbits derived using microwave measurements as provided by the International GPS Service (IGS). The orbit validation is based on the difference between the observed range (SLR measurements) and the computed range (assuming that the satellite positions are know from the IGS). The resulting range residuals are primarily an indicator for the radial accuracy of the microwave orbits. This validation method is well-known and several validation results have been published in the last 10 years. The IGS analysis center CODE (Center for Orbit Determination in Europe) provides on a routine base daily range residuals for all GNSS satellites observed by both, SLR and microwave techniques. We present results of our recent range residual analysis for two GPS satellites (PRN G05, G06) and three GLONASS satellites (PRN R03, R22, R24). Microwave orbits provided by IGS and CODE are used as well as SLR normal point observations of 13 globally distributed sites. The resulting range residual time series of about 3.3 years, starting in January 2001, for GPS satellites and of about 10 months, starting in June 2003, for GLONASS satellites are analyzed. The comparison of the range residuals with previous analysis results shows the impact of several improvements, i.e., the increasing quality of the microwave orbit as well as the use of new laser retroreflector arrays on GLONASS satellites launched after 1995. The validation of the CODE orbits shows a standard deviation of 2.7 cm for the GPS satellites and of 4.9 cm for the GLONASS satellites. A bias of about -5.8 cm for GPS satellites and of -2.3 cm for GLONASS satellites between the SLR measurements and the microwave orbits was determined. The cause of these biases is not yet fully understood. Pass-specific systematics in the range residuals were found, but it was not possible to assign them to station- or satellite-specific error sources

  12. a Three-Dimensional Orbit for Capella

    Science.gov (United States)

    Branham, Richard L.

    2008-09-01

    Semidefinite programming is applied to 169 interferometric observations of Capella, made between 1919 and 1999, and 221 double-line radial velocities, obtained between 1896 and 1991, to calculate a three-dimensional orbit. The data are reduced with the robust L 1 criterion. The orbit is nearly circular, eccentricity of 0.00508, with a semimajor axis of 0farcs056 and period of 104.039 days. The mass of the primary is calculated to be 3.049 M sun, that of the secondary 2.569 M sun, and the parallax of the system is calculated to be 74.85 mas. Another orbit is calculated, but using only the best data, Mark III interferometric observations, and Coralie radial velocities. Although the mean errors for this orbit are considerably smaller, reasons are given for preferring the orbit calculated from all of the data as opposed to only the best data: the residuals are more random, the parallax agrees better with van Leeuwen's re-reduction of the Hipparcos parallax, and the Shannon uncertainty is lower.

  13. Clustering of periodic orbits in chaotic systems

    Science.gov (United States)

    Gutkin, Boris; Osipov, Vladimir Al

    2013-01-01

    In the framework of the semiclassical approach, the universal spectral correlations in Hamiltonian systems with classical chaotic dynamics can be attributed to the systematic correlations between the actions of periodic orbits which (up to the switch in the momentum direction) pass through approximately the same points of the phase space. By considering symbolic dynamics of the system one can introduce a natural ultrametric distance between periodic orbits and organize them into clusters of orbits approaching each other in the phase space. We study the distribution of cluster sizes for the baker's map in the asymptotic limit of long trajectories. This problem is equivalent to the one of counting degeneracies in the length spectrum of the de Bruijn graphs. Based on this fact, we derive the probability P_k that k randomly chosen periodic orbits belong to the same cluster. Furthermore, we find asymptotic behaviour of the largest cluster size |C_{\\max}| and derive the probability P(t) that a random periodic orbit belongs to a cluster smaller than t|C_{\\max}| , t ∈ [0, 1].

  14. Imaging diagnosis of orbital Wegener granulomatosis

    Science.gov (United States)

    Yang, Bin; Yin, Zhijian; Chen, Shuai; Yuan, Feng; Zhao, Wei; Yang, Yaying

    2017-01-01

    Abstract Introduction: Wegener granulomatosis (WG) is a rare idiopathic autoimmune disease causing necrotizing granulomatous vasculitis. Whether as the first symptom or as part of systemic changes, ocular manifestations in WG patients are not specific. Any part of the eyes can be affected, with the anterior segment and orbit most commonly involved. So, early diagnosis and treatment are essential for controlling the progression of the disease and improving the quality of life for patients. Clinical findings/Patient concerns: Here we present a rare case of orbital WG of a 22-year-old woman was admitted to the hospital because of intense pain associated with decreased visual acuity in her right eye since 1 day. She had been previously diagnosed with WG at our hospital. Imaging diagnosis: Orbital computed tomography imaging showed diffuse swelling of intraorbital muscles, and space-occupying lesions were present in both eyes. Most postnasal anatomical structures were absent, appearing as a massive cavity shadow. Orbital magnetic resonance imaging showed a shadow of orbital soft tissues. Conclusion: WG is a serious, fatal disease. Early diagnosis and treatment are essential for controlling the progression of the disease and improving the quality of life for patients. PMID:28591026

  15. Biomechanic Factors Associated With Orbital Floor Fractures.

    Science.gov (United States)

    Patel, Sagar; Andrecovich, Christopher; Silverman, Michael; Zhang, Liying; Shkoukani, Mahdii

    2017-07-01

    Orbital floor fractures are commonly seen in clinical practice, yet the etiology underlying the mechanism of fracture is not well understood. Current research focuses on the buckling theory and hydraulic theory, which implicate trauma to the orbital rim and the globe, respectively. To elucidate and define the biomechanical factors involved in an orbital floor fracture. A total of 10 orbits from 5 heads (3 male and 2 female) were used for this study. These came from fresh, unfixed human postmortem cadavers that were each selected so that the cause of death did not interfere with the integrity of orbital walls. Using a drop tower with an accelerometer, we measured impact force on the globe and rim of cadaver heads affixed with strain gauges. The mean impacts for rim and globe trauma were 3.9 J (95% CI, 3.4-4.3 J) and 3.9 J (95% CI, 3.5-4.3 J), respectively. Despite similar impact forces to the globe and rim, strain-gauge data displayed greater mean strain for globe impact (6563 μS) compared with rim impact (3530 μS); however, these data were not statistically significant (95% CI, 3598-8953 μS; P = .94). Our results suggest that trauma directly to the globe predisposes a patient to a more posterior fracture while trauma to the rim demonstrates an anterior predilection. Both the hydraulic and buckling mechanisms of fracture exist and demonstrate similar fracture thresholds. NA.

  16. Biomaterials and implants for orbital floor repair.

    Science.gov (United States)

    Baino, Francesco

    2011-09-01

    Treatment of orbital floor fractures and defects is often a complex issue. Repair of these injuries essentially aims to restore the continuity of the orbital floor and to provide an adequate support to the orbital content. Several materials and implants have been proposed over the years for orbital floor reconstruction, in the hope of achieving the best clinical outcome for the patient. Autografts have been traditionally considered as the "gold standard" choice due to the absence of an adverse immunological response, but they are available in limited amounts and carry the need for extra surgery. In order to overcome the drawbacks related to autografts, researchers' and surgeons' attention has been progressively attracted by alloplastic materials, which can be commercially produced and easily tailored to fit a wide range of specific clinical needs. In this review the advantages and limitations of the various biomaterials proposed and tested for orbital floor repair are critically examined and discussed. Criteria and guidelines for optimal material/implant choice, as well as future research directions, are also presented, in an attempt to understand whether an ideal biomaterial already exists or a truly functional implant will eventually materialise in the next few years. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. A retrograde object near Jupiter's orbit

    Science.gov (United States)

    Connors, M.; Wiegert, P.

    2018-02-01

    Asteroid 2007 VW266 is among the rare objects with a heliocentric retrograde orbit, and its semimajor axis is within a Hill sphere radius of that of Jupiter. This raised the interesting possibility that it could be in co-orbital retrograde resonance with Jupiter, a second "counter-orbital" object in addition to recently discovered 2015 BZ509. We find instead that the object is in 13/14 retrograde mean motion resonance (also referred to as 13/-14). The object is shown to have entered its present orbit about 1700 years ago, and it will leave it in about 8000 years, both through close approach to Jupiter. Entry and exit states both avoid 1:1 retrograde resonance, but the retrograde nature is preserved. The temporary stable state is due to an elliptic orbit with high inclination keeping nodal passages far from the associated planet. We discuss the motion of this unusual object based on modeling and theory, and its observational prospects.

  18. Orbital and intracranial complications after acute rhinosinusitis.

    Science.gov (United States)

    Kastner, Jan; Taudy, Milos; Lisy, Jiri; Grabec, Paul; Betka, Jan

    2010-12-01

    Nowadays, intracranial abscess is a rare complication of acute rhinosinusitis. The consequent orbital and intracranial complications of acute rhinosinusitis are rare but must be mutually excluded in complicated rhinosinusitis even when proper surgical and medical treatment tend to efficiently heal the orbital complication. We report a case of a patient who primarily revealed symptoms of orbitocellulitis as a complication of odontogenous rhinosinusitis. Proper diagnostic and therapeutical measures were undertaken to manage the disease immediately after stationary admission. Two weeks after an inconspicuous healing period, hemiparesis due to formation of an intracranial abscess developed. An emergent situation reveals which was unusual to the clinical situation. The possible role of underlying mechanisms of intracranial abscess formation is discussed and review of literature concerning orbital and intracranial rhinosinusitis complications is performed. The correct indication of imaging methods and accurate evaluation of diminutive symptoms are essential. We assume that performance of a complementary CT of the brain or MRI even when previous CT scan of the orbit/paranasal sinuses reveals no cerebral pathology should be done to avoid or minimize future patients with consecutive orbital and intracranial complications of acute rhinosinusitis.

  19. Orbital schwannomatosis in the absence of neurofibromatosis.

    Science.gov (United States)

    Koktekir, Bengu Ekinci; Kim, H Jane; Geske, Mike; Bloomer, Michelle; Vagefi, Reza; Kersten, Robert C

    2014-11-01

    The aim of this study was to describe 3 cases of primary orbital schwannomatosis without associated systemic neurofibromatosis. This is a retrospective interventional study of 3 patients who presented with multiple, distinct masses in the orbit (n = 3) as well as in the hemiface (n = 1). The clinical presentation, imaging features, surgical procedures, and outcomes were defined. Two women and a man presented with of exophthalmos and diplopia. Pain was the most prominent complaint in 2 patients. None of the patients had associated systemic neurofibromatosis by history or examination. Radiologic evaluation with computed tomography or magnetic resonance imaging of orbit revealed multiple well-demarcated intraconal and extraconal masses. Masses were excised, and histopathology confirmed all masses to be schwannomas. Postoperative follow-up was uneventful with alleviation of primary complaints in all patients. Multiple orbital schwannomas (primary orbital schwannomatosis) may be observed in patients without systemic association of neurofibromatosis. Management includes surgical excision of the tumors to achieve relief from their mass effects.

  20. An analysis of near-circular lunar mapping orbits

    Indian Academy of Sciences (India)

    Numerical investigations have been carried out to analyse the evolution of lunar circular orbits and the influence of the higher order harmonics of the lunar gravity field. The aim is to select the appropriate near-circular orbit characteristics, which extend orbit life through passive orbit maintenance. The spherical harmonic ...

  1. Inclination of the orbital planes of visual binaries

    Directory of Open Access Journals (Sweden)

    Popović G.M.

    1998-01-01

    Full Text Available The inclination of the orbital planes of 78 visual binaries with known orbits with respect to the galactic was examined. No double star groupings were found having approximately equal orientation of their orbital planes. Viewed the orbital plane north poles there are more binary systems with counterclockwise motion than those moving clockwise.

  2. Orbital cellulitis complicating sinusitis: a 15-year review | Nwaorgu ...

    African Journals Online (AJOL)

    Background: Orbital cellulitis is an infection of the orbital soft tissues behind the orbital septum. Primary sinus infection is the most common cause of orbital cellulites. It is an ocular emergency that threatens not only vision but also life from complications such as meningitis, cavernous sinus thrombosis, and brain abscess.

  3. Orbital nematic order and interplay with magnetism in the two-orbital Hubbard model.

    Science.gov (United States)

    Wang, Zhentao; Nevidomskyy, Andriy H

    2015-06-10

    Motivated by the recent angle-resolved photoemission spectroscopy (ARPES) on FeSe and iron pnictide families of iron-based superconductors, we have studied the orbital nematic order and its interplay with antiferromagnetism within the two-orbital Hubbard model. We used random phase approximation (RPA) to calculate the dependence of the orbital and magnetic susceptibilities on the strength of interactions and electron density (doping). To account for strong electron correlations not captured by RPA, we further employed non-perturbative variational cluster approximation (VCA) capable of capturing symmetry broken magnetic and orbitally ordered phases. Both approaches show that the electron and hole doping affect the two orders differently. While hole doping tends to suppress both magnetism and orbital ordering, the electron doping suppresses magnetism faster. Crucially, we find a realistic parameter regime for moderate electron doping that stabilizes orbital nematicity in the absence of long-range antiferromagnetic order. This is reminiscent of the non-magnetic orbital nematic phase observed recently in FeSe and a number of iron pnictide materials and raises the possibility that at least in some cases, the observed electronic nematicity may be primarily due to orbital rather than magnetic fluctuations.

  4. Artificial satellites orbiting planetary satellites: critical inclination and sun-synchronous orbits

    Science.gov (United States)

    da Costa, Maria Lívia G. T. X.; Vilhena de Moraes, Rodolpho; Carvalho, Jean Paulo S.; Prado, Antônio Fernando B. A.

    2017-10-01

    The behavior of critical inclinations and sun-synchronous orbits of artificial satellites orbiting planetary satellites are analyzed considering, simultaneously, the influence of the harmonics J 2 and C 22, both due to the non-uniform mass distribution of the natural satellite. In the present research, the central bodies of interest are the Moon and two of the Galilean moons: Io and Europa.

  5. Gaussian-Type Orbitals versus Slater-Type Orbitals: A Comparison

    Science.gov (United States)

    Magalha~es, Alexandre L.

    2014-01-01

    The advantages of Gaussian-type orbitals (GTO) over Slater-type orbitals (STO) in quantum chemistry calculations are clarified here by means of a holistic approach. The popular Microsoft Office Excel program was used to create an interactive application with which students are able to explore the features of GTO, including automatic calculations…

  6. An augmented reality application for studying atomic orbitals : orbitário

    OpenAIRE

    Trindade, Jorge; Kirner, Claudio; Fiolhais, Carlos

    2004-01-01

    "Virtual environments seem to facilitate the formation of correct conceptual models. The main contributing factor is interaction. Augmented reality is a new sort of virtual reality with a new form of interaction. We present Orbitário, an augmented reality application for studying atomic orbitals."

  7. Distichiasis following transconjunctival approach to the inferior orbital rim and orbital floor

    Directory of Open Access Journals (Sweden)

    Saoussen Salhi

    2015-09-01

    Full Text Available Zygoma fractures are often associated with orbital floor fractures, which can be approached through a transconjunctival or transcutaneous incision. The transconjunctival approach has gained popularity over the transcutaneous one for its overall lower complication rate. We describe a patient with a zygoma fracture where the inferior orbital rim and orbital floor were exposed, reduced and fixated through a transconjunctival incision. Postoperatively, the patient developed a row of eyelashes posterior to the normal lash line, a condition termed distichiasis, causing corneal irritation and ulceration. This is believed to be caused by the postoperative eyelid inflammation induced by the transconjunctival incision. The condition was treated by electrolysis with no recurrence of symptoms. This condition has never been described as a postoperative complication of a transconjunctival approach to an inferior orbital rim and orbital floor fracture.

  8. Orbital Perivenous Abscess Complicating the Diagnosis and Management of Orbital Cellulitis.

    Science.gov (United States)

    Verma, Rohan; Lee, Bradford W; Alameddine, Ramzi M; Ko, Audrey C; Khanna, Paritosh C; Kikkawa, Don O; Korn, Bobby S

    An 11-year-old female presented with orbital cellulitis, bacterial sinusitis, enlarged left superior ophthalmic vein, dural venous sinuses, and internal jugular vein. The patient underwent endoscopic sinus surgery and was started on intravenous antibiotics and anticoagulation with limited improvement in orbital signs and symptoms. A magnetic resonance imaging/magnetic resonance venography of the orbits and brain revealed a dilated left superior ophthalmic vein with absence of flow but no clearly discernible orbital abscess. Intravenous corticosteroids resulted in dramatic improvement of pain, hypoglobus, proptosis, and extraocular motility, all of which rapidly recurred on discontinuation. Serial imaging revealed progression of what eventually manifested as a well-defined, rim-enhancing peri-superior ophthalmic vein abscess, which was incised and drained with prompt resolution of orbital cellulitis and complete visual recovery.

  9. Microsurgical Anatomy of the Orbit: The Rule of Seven

    Directory of Open Access Journals (Sweden)

    Carolina Martins

    2011-01-01

    Full Text Available The orbits are paired structures, located on the anterior part of the face. Morphologically, each orbit is a four sided pyramid with a posterior apex and anterior base. In the orbit, all openings are arranged around the base, apex or between the orbital walls. An anatomical characteristic of the orbit is that structures are arranged in groups of seven: there are seven bones, seven intraorbital muscles and seven nerves in the orbit. Tumors confined within the periorbita in the anterior two thirds of the orbit can often be approached extracranially, but those located in the apical area, and especially those on the medial side of the optic nerve, often require a transcranial approach. Thus, knowledge of orbital osteology is paramount in adequately choosing and performing an orbital approach. Understanding the critical topographical elements in this area helps to classify an orbital lesion and provides for a solid basis in choosing the most adequate intraorbital route for its treatment.

  10. Mars Molniya Orbit Atmospheric Resource Mining

    Science.gov (United States)

    Mueller, Robert P.; Braun, Robert D.; Sibille, Laurent; Sforzo, Brandon; Gonyea, Keir; Ali, Hisham

    2016-01-01

    This NIAC (NASA Advanced Innovative Concepts) work will focus on Mars and will build on previous efforts at analyzing atmospheric mining at Earth and the outer solar system. Spacecraft systems concepts will be evaluated and traded, to assess feasibility. However the study will primarily examine the architecture and associated missions to explore the closure, constraints and critical parameters through sensitivity studies. The Mars atmosphere consists of 95.5 percent CO2 gas which can be converted to methane fuel (CH4) and Oxidizer (O2) for chemical rocket propulsion, if hydrogen is transported from electrolyzed water on the Mars surface or from Earth. By using a highly elliptical Mars Molniya style orbit, the CO2 atmosphere can be scooped, ram-compressed and stored while the spacecraft dips into the Mars atmosphere at periapsis. Successive orbits result in additional scooping of CO2 gas, which also serves to aerobrake the spacecraft, resulting in a decaying Molniya orbit.

  11. Orbital melanoma with calcification: A diagnostic dilemma

    Directory of Open Access Journals (Sweden)

    Sukhdeep Bains

    2016-01-01

    Full Text Available Primary orbital melanoma is rare and has varied initial presentation. A 28-year-old female presented with proptosis and decreased vision in the left eye. Computed tomography scan showed an orbital mass with contrast enhancement and calcification around the optic nerve leading to a diagnosis of meningioma. The patient chose to be on observation. Loss of vision with an increase in proptosis was seen at 6 months follow-up. On surgical exploration, a well-defined pigmented mass was seen encasing the optic nerve. Histopathological analysis revealed a malignant melanoma. Metastatic workup was negative. Left eye lid sparing exenteration was done. A high index of suspicion is necessary in a rapidly growing suspected optic nerve sheath meningioma and a differential diagnosis including orbital melanoma be considered.

  12. Catalogue of Cometary Orbits 1995. Tenth edition.

    Science.gov (United States)

    Marsden, B. G.; Williams, G. V.

    This tenth edition of the Catalogue of Cometary Orbits differs from its predecessors in that it utilizes the new cometary designation system that took effect at the beginning of 1995, adopted by the IAU in August 1994. It contains 1472 orbits for 1444 cometary apparitions and is intended to be complete for comets observed through the end of 1994. Contents: 1. Introduction. 2. General catalogue (long-period and unnumbered periodic comets, numbered periodic comets). 3. Identifications. 4. 1995 elements for numbered periodic comets. 5. Statistical tables (periodic comets of more than one appearance, periodic comets of only one appearance, comets that may be of short period, parabolic and nearly-parabolic orbits in order of i). 6. Correspondence of new-style and old-style designations (by Roman numeral, by letter designation). 7. X/comets.

  13. Infantile maxillary sinus osteomyelitis mimicking orbital cellulitis

    Directory of Open Access Journals (Sweden)

    Nagarajan Krishnan

    2014-01-01

    Full Text Available Periorbital soft tissue swelling may result due to primary orbital pathology or from adjacent facio-maxillary or sino-nasal inflammatory causes. Osteomyelitis of maxilla in the pediatric age group is a rare entity in this era of antibiotics. We present an 11-month-old female infant who was brought with peri-orbital selling and purulent nasal discharge. Computed Tomography showed erosions of the walls of maxillary sinus suggestive of osteomyelitis. Culture of sinus scraping showed Staphylococcus aureus growth and the child improved with intravenous cloxacillin therapy. This case is presented due to the rarity of its presentation in this age group and for awareness to consider this entity in children having fever and peri-orbital swelling.

  14. Orbital Cellulitis Following Uncomplicated Aqueous Shunt Surgery.

    Science.gov (United States)

    Beck, Daniel E R; El-Assal, Karim S L; Doherty, Mark D; Wride, Nicholas K

    2017-02-01

    To date, there have only been 5 reported cases of orbital cellulitis following implantation of an aqueous tube shunt for glaucoma. Previously reported cases have involved eyes with significant comorbidities and successful management has often required the removal of the device alongside systemic antibiotic therapy. We present a 53-year-old man with severe orbital cellulitis, 3 months after routine implantation of a Baerveldt tube shunt for primary open angle glaucoma. The patient was managed medically, with topical and systemic antibiotic therapy. The patient went on to make a full recovery with the tube in situ. We report that a more conservative approach (without tube removal) to be successful in a case where there is no evidence of tube exposure. It is important to appreciate that in some cases of orbital cellulitis without clear signs of intraocular involvement, a tube can be left in situ.

  15. An eye for trouble: orbital cellulitis

    Science.gov (United States)

    Armstrong, P A R; Nichol, N M

    2006-01-01

    Patients with orbital cellulitis present to emergency departments occasionally. Symptoms usually develop rapidly, with patients being distressed by painful ocular movements and systemic upset. The case of a 24‐year‐old man who had a 1‐month gradual history of intermittent periorbital swelling after a flu‐like illness, and subsequently developed a large intracranial extradural abscess eroding through the temporal bone, ultimately requiring neurosurgical intervention is presented. Although orbital and periorbital swelling is common after acute sinusitis, cellulitis and intracranial abscess are rare but potentially life threatening and sight threatening. Accurate diagnosis is therefore of great importance. In this case, the patient presented with few clinical signs but relevant pathology. The importance of assessing ocular movement, which is a major clinical abnormality indicating orbital disorder and thus an aid to accurate diagnosis, should be highlighted. PMID:17130587

  16. Europa Planetary Protection for Juno Jupiter Orbiter

    Science.gov (United States)

    Bernard, Douglas E.; Abelson, Robert D.; Johannesen, Jennie R.; Lam, Try; McAlpine, William J.; Newlin, Laura E.

    2010-01-01

    NASA's Juno mission launched in 2011 and will explore the Jupiter system starting in 2016. Juno's suite of instruments is designed to investigate the atmosphere, gravitational fields, magnetic fields, and auroral regions. Its low perijove polar orbit will allow it to explore portions of the Jovian environment never before visited. While the Juno mission is not orbiting or flying close to Europa or the other Galilean satellites, planetary protection requirements for avoiding the contamination of Europa have been taken into account in the Juno mission design.The science mission is designed to conclude with a deorbit burn that disposes of the spacecraft in Jupiter's atmosphere. Compliance with planetary protection requirements is verified through a set of analyses including analysis of initial bioburden, analysis of the effect of bioburden reduction due to the space and Jovian radiation environments, probabilistic risk assessment of successful deorbit, Monte-Carlo orbit propagation, and bioburden reduction in the event of impact with an icy body.

  17. Summary of ACCSIM and ORBIT Benchmarking Simulations

    CERN Document Server

    AIBA, M

    2009-01-01

    We have performed a benchmarking study of ORBIT and ACCSIM which are accelerator tracking codes having routines to evaluate space charge effects. The study is motivated by the need of predicting/understanding beam behaviour in the CERN Proton Synchrotron Booster (PSB) in which direct space charge is expected to be the dominant performance limitation. Historically at CERN, ACCSIM has been employed for space charge simulation studies. A benchmark study using ORBIT has been started to confirm the results from ACCSIM and to profit from the advantages of ORBIT such as the capability of parallel processing. We observed a fair agreement in emittance evolution in the horizontal plane but not in the vertical one. This may be partly due to the fact that the algorithm to compute the space charge field is different between the two codes.

  18. Spin and orbital moments in actinide compounds

    DEFF Research Database (Denmark)

    Lebech, B.; Wulff, M.; Lander, G.H.

    1991-01-01

    The extended spatial distribution of both the transition-metal 3d electrons and the actinide 5f electrons results in a strong interaction between these electron states when the relevant elements are alloyed. A particular interesting feature of this hybridization, which is predicted by single-electron...... band-structure calculations, is that the orbital moments of the actinide 5f electrons are considerably reduced from the values anticipated by a simple application of Hund's rules. To test these ideas, and thus to obtain a measure of the hybridization, we have performed a series of neutron scattering...... experiments designed to determine the magnetic moments at the actinide and transition-metal sublattice sites in compounds such as UFe2, NpCo2, and PuFe2 and to separate the spin and orbital components at the actinide sites. The results show, indeed, that the ratio of the orbital to spin moment is reduced...

  19. Stable orbits for lunar landing assistance

    Science.gov (United States)

    Condoleo, Ennio; Cinelli, Marco; Ortore, Emiliano; Circi, Christian

    2017-10-01

    To improve lunar landing performances in terms of mission costs, trajectory determination and visibility the use of a single probe located over an assistance orbit around the Moon has been taken into consideration. To this end, the properties of two quasi-circular orbits characterised by a stable behaviour of semi-major axis, eccentricity and inclination have been investigated. The analysis has demonstrated the possibility of using an assistance probe, located over one of these orbits, as a relay satellite between lander and Earth, even in the case of landings on the far side of the Moon. A comparison about the accuracy in retrieving the lander's state with respect to the use of a probe located in the Lagrangian point L2 of the Earth-Moon system has also been carried out.

  20. Measurement of orbital volume by computed tomography. Especially on the growth of orbit

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Minoru [Fukushima Medical Coll. (Japan)

    2000-10-01

    Using reconstructed X-ray computed tomography (CT) images of serial coronal sections, we measured the orbital volume and studied its changes with age. The subjects consisted of 109 patients (74 males, 35 females) who had undergone X-ray CT. After the reproducibility of orbital volume measurements and laterality in individuals were confirmed, the relation between the orbital volume and the age, sex, weight, and interlateral orbital rim distance were examined. The difference between two measurements in the same patients was 0.4% for measured volume, which showed the reproducibility of this measurement to be good. The laterality in individuals was 0.06 cm{sup 3}: this difference was very small and not significant. The orbital volume showed no unbalance between the right and left at any stage of growth. Both the height and the interlateral orbital rim distance had a strong correlation with the orbital volume. Referring to the relation between age and orbital volume, a strong correlation with an almost identical approximate equation was obtained for both sexes under 12 years of age. Presumably, the rapid growth of the orbit comes to an end by 15 years of age in males and 11 years in females. This means that more than 95% growth of adults has already been completed in the first half of the teens. The mean orbital volume in adult Japanese is 23.6{+-}2.0 (mean{+-}standard deviation) cm{sup 3} in males and 20.9{+-}1.3 cm{sup 3} in females. (author)

  1. Orbital Characteristics of Binary Systems after Asymmetric Supernova Explosions

    OpenAIRE

    Kalogera, Vassiliki

    1996-01-01

    We present an analytical method for studying the changes of the orbital characteristics of binary systems with circular orbits due to a kick velocity imparted to the newborn neutron star during a supernova explosion (SN). Assuming a Maxwellian distribution of kick velocities we derive analytical expressions for the distribution functions of orbital separations and eccentricities immediately after the explosion, of orbital separations after circularization of the post-SN orbits, and of systemi...

  2. Colliding Stellar Wind Models with Orbital Motion

    Science.gov (United States)

    Wilkin, Francis P.; O'Connor, Brendan

    2018-01-01

    We present thin-shell models for the collision between two ballistic stellar winds, including orbital motion.The stellar orbits are assumed circular, so that steady-state solutions exist in the rotating frame, where we include centrifugal and Coriolis forces. Exact solutions for the pre-shock winds are incorporated. Here we discuss 2-D model results for equal wind momentum-loss rates, although we allow for the winds to have distinct speeds and mass loss rates. For these unequal wind conditions, we obtain a clear violation of skew-symmetry, despite equal momentum loss rates, due to the Coriolis force.

  3. Sinonasal disease and orbital cellulitis in children.

    Science.gov (United States)

    Meara, Daniel J

    2012-08-01

    Sinonasal disease is common in the pediatric population because of anatomic, environmental, and physiologic factors. Once paranasal sinusitis develops, orbital cellulitis is a concerning sequela that can result in loss of visual acuity and even intracranial disease. Thus, a clear history and physical examination in conjunction with radiographic studies are critical to a correct diagnosis and timely institution of treatment that may include hospitalization, serial ophthalmologic examinations, intravenous antibiotics, and surgery. The serious nature of orbital cellulitis in children cannot be overestimated; but, if prompt and appropriate treatment is initiated, the prognosis is excellent and long-term sequelae should be limited. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Space Shuttle Orbiter windshield bird impact analysis

    Science.gov (United States)

    Edelstein, Karen S.; McCarty, Robert E.

    The NASA Space Shuttle Orbiter's windshield employs three glass panes separated by air gaps. The brittleness of the glass offers much less birdstrike energy-absorption capability than the laminated polycarbonate windshields of more conventional aircraft; attention must accordingly be given to the risk of catastrophic bird impact, and to methods of strike prevention that address bird populations around landing sites rather than the modification of the window's design. Bird populations' direct reduction, as well as careful scheduling of Orbiter landing times, are suggested as viable alternatives. The question of birdstrike-resistant glass windshield design for hypersonic aerospacecraft is discussed.

  5. Optimal trajectories for aeroassisted, coplanar orbital transfer

    Science.gov (United States)

    Miele, A.; Basapur, V. K.; Lee, W. Y.

    1987-01-01

    Classical and minimax optimal control problems arising in the study of aeroassisted coplanar orbit transfer from a high planetary orbit to a low one are considered. Attention is given to (1) the minimization of the energy required for the maneuver; (2) minimization of the time integral of the heating rate; (3) minimization of the time of flight during the atmospheric portion of the trajectory; (4) maximization of the time of flight during the atmospheric portion of the trajectory; (5) minimization of the time integral of the path inclination; and (6) minimization of the sum of the squares of the entry and exit path inclinations.

  6. Accelerated rotation with orbital angular momentum modes

    CSIR Research Space (South Africa)

    Schulze, C

    2015-01-01

    Full Text Available ) Accelerated rotation with orbital angular momentum modes Christian Schulze,1 Filippus S. Roux,2 Angela Dudley,2 Ronald Rop,3 Michael Duparre´,1 and Andrew Forbes2,4,* 1Institute of Applied Optics, Friedrich Schiller University, Fro¨belstieg 1, 07743 Jena... from the transverse acceleration discussed before. We tailor our “twisted light” (fields carrying orbital angular momentum) to have a nonlinear phase variation with azimuthal angle, which we show is the building block for angular accelerating light...

  7. Orbit Representations from Linear mod 1 Transformations

    Directory of Open Access Journals (Sweden)

    Carlos Correia Ramos

    2012-05-01

    Full Text Available We show that every point $x_0in [0,1]$ carries a representationof a $C^*$-algebra that encodes the orbit structure of thelinear mod 1 interval map $f_{eta,alpha}(x=eta x +alpha$. Such $C^*$-algebra is generated by partial isometries arising from the subintervals of monotonicity of the underlying map $f_{eta,alpha}$. Then we prove that such representation is irreducible. Moreover two such of representations are unitarily equivalent if and only if the points belong to the same generalized orbit, for every $alphain [0,1[$ and $etageq 1$.

  8. Mitigating Climate Change with Earth Orbital Sunshades

    Science.gov (United States)

    Coverstone, Victoria; Johnson, Les

    2015-01-01

    An array of rotating sunshades based on emerging solar sail technology will be deployed in a novel Earth orbit to provide near-continuous partial shading of the Earth, reducing the heat input to the atmosphere by blocking a small percentage of the incoming sunlight, and mitigating local weather effects of anticipated climate change over the next century. The technology will provide local cooling relief during extreme heat events (and heating relief during extreme cold events) thereby saving human lives, agriculture, livestock, water and energy needs. A synthesis of the solar sail design, the sails' operational modes, and the selected orbit combine to provide local weather modification.

  9. Numerical orbit generators of artificial earth satellites

    Science.gov (United States)

    Kugar, H. K.; Dasilva, W. C. C.

    1984-04-01

    A numerical orbit integrator containing updatings and improvements relative to the previous ones that are being utilized by the Departmento de Mecanica Espacial e Controle (DMC), of INPE, besides incorporating newer modellings resulting from the skill acquired along the time is presented. Flexibility and modularity were taken into account in order to allow future extensions and modifications. Characteristics of numerical accuracy, processing quickness, memory saving as well as utilization aspects were also considered. User's handbook, whole program listing and qualitative analysis of accuracy, processing time and orbit perturbation effects were included as well.

  10. Periodic orbits near a bifurcating slow manifold

    DEFF Research Database (Denmark)

    Kristiansen, Kristian Uldall

    2015-01-01

    (\\epsilon^{1/3})$-distance from the union of the normally elliptic slow manifolds that occur as a result of the bifurcation. Here $\\epsilon\\ll 1$ measures the time scale separation. These periodic orbits are predominantly unstable. The proof is based on averaging of two blowup systems, allowing one to estimate...... the effect of the singularity, combined with results on asymptotics of the second Painleve equation. The stable orbits of smallest amplitude that are {persistently} obtained by these methods remain slightly further away from the slow manifold being distant by an order $\\mathcal O(\\epsilon^{1/3}\\ln^{1/2}\\ln...

  11. Neuro-Sweet Disease Causing Orbital Inflammation.

    Science.gov (United States)

    Taravati, Parisa

    2015-02-01

    Neuro-Sweet disease is a rare condition causing encephalitis or meningitis in addition to the erythematous skin plaques of Sweet syndrome. Neuro-Sweet disease has been associated with several ocular manifestations, including ocular movement disorders, episcleritis, conjunctivitis, uveitis, and optic disc oedema. The author reports a patient with orbital inflammation, cranial neuropathies, and a skin rash in the setting of myelodysplastic syndrome. Biopsy of her skin lesion confirmed the diagnosis of neuro-Sweet disease. To the author's knowledge, this is the first reported case of neuro-Sweet disease causing orbital inflammation. Her ocular inflammation resolved with the use of systemic corticosteroid treatment.

  12. Orbital maneuvers around irregular shaped bodies

    Science.gov (United States)

    Venditti, Flaviane; Rocco, E. M.; Almeida Prado, A. B.

    2013-05-01

    Abstract (2,250 Maximum Characters): In the solar system there are many small bodies called asteroids. The large majority of these bodies are located in the asteroid belt, between the orbits of the planets Mars and Jupiter. The Near- Earth Objects, or NEOs, are objects with perihelion below 1.3AU, which include comets and asteroids. The NEOs are considered to have orbits passing close to the Earth’s orbit and, in the case of asteroids, are called Near-Earth Asteroids (NEAs). Among the NEAs there are bodies considered potentially hazardous asteroids (PHAs), whose minimum orbit intersection distance with Earth is 0.05AU and that have absolute magnitude (H) of 22, which would mean an asteroid of at least 110-240 meters, depending on its albedo. One of the major characteristic of the asteroids is the irregular shape, causing the dynamics of orbits around these bodies to be different from a spherical shaped one. The fact that an object is not spherical generates a perturbation on the gravitational field. The disturbing force can be determined considering the shape of the specific body. A satellite orbiting this body would suffer the effects of this perturbation, but knowing the disturbing force, it’s possible to correct and control the orbit according to the desired mission. The polyhedron method is a traditional way to model an asteroid by dividing the object into smaller parts. The data used on this work are composed by a combination of triangular faces. The total disturbing force is a sum of the force on each piece of the model. Therefore, after the simulations are obtained, it’s possible to apply the desired corrections of the perturbation using continuous low thrust in closed loop, making it possible to perform maneuvers near these bodies. One of the important applications of the study shown above is in the ASTER mission, that is under study by INPE and several other Brazilian academic institutions, which goal is to send a spacecraft to an asteroid and then

  13. Viking orbiter and its Mariner inheritance

    Science.gov (United States)

    1984-01-01

    Improvements to the design of the Mariner spacecraft resulted in the Viking spacecraft. The Viking spacecraft would consist of two major systems - an orbiter and a lander, while the lander would provide the means for safely delivering the scientific instruments to the surface, house, and provide the necessary power source and communication links for those experiments, the orbiter would transport the lander to Mars, rovide a platform for the Viking imaging system so that proposed landing sites could be surveyed and certified, relay lander science information back to Earth, and conduct scientific observations in its own right.

  14. Orbit equivalence and actions of F

    DEFF Research Database (Denmark)

    Törnquist, Asger Dag

    2006-01-01

    In this paper we show that there are "E many" orbit inequivalent free actions of the free groups F, 2 ≤ n ≤ ∞ by measure preserving transformations on a standard Borel probability space. In particular, there are uncountably many such actions.......In this paper we show that there are "E many" orbit inequivalent free actions of the free groups F, 2 ≤ n ≤ ∞ by measure preserving transformations on a standard Borel probability space. In particular, there are uncountably many such actions....

  15. Photogrammetric application of Viking orbital photography

    Science.gov (United States)

    Wu, S. S. C.; Elassal, A. A.; Jordan, R.; Schafer, F. J.

    1982-01-01

    The paper describes special techniques for the photogrammetric compilation of topographic maps and profiles from stereoscopic photographs taken by the two Viking Orbiter spacecraft. These techniques were developed because the extremely narrow field of view of the Viking cameras rules out compilation by conventional photogrammetric methods. The techniques adjust for internal consistency the Supplementary Experimental Data Record and the computation of geometric orientation parameters of the stereo models. A series of contour maps of Mars is being compiled by these new techniques using a wide variety of Viking Orbiter photographs.

  16. Restoration of the orbital aesthetic subunit in complex midface defects.

    Science.gov (United States)

    Chepeha, Douglas B; Wang, Steven J; Marentette, Lawrence J; Bradford, Carol R; Boyd, Charles M; Prince, Mark E; Teknos, Theodoros N

    2004-10-01

    Although various options exist for restoration of the orbital defect in complex craniofacial resections, the aesthetic appearance and functional result of the orbit are optimized when the bony orbital architecture, orbital volume, and facial contour are specifically addressed. The study describes an approach using free tissue transfer for restoration of the native orbital aesthetic subunit. Retrospective case series. Nineteen patients (male-to-female ratio, 14:5; mean age, 52 y [age range, 8-79 y]) in the study period between 1997 and 2001 had orbital defects that could be classified into one of the following categories: 1) orbital exenteration cavities only, 2) orbital exenteration cavities with resection of less than 30% of the bony orbital rim, or 3) radical orbital exenteration cavities with resection of overlying skin and bony malar eminence. Group 1 had reconstructions with fasciocutaneous forearm flaps; group 2, with osseocutaneous forearm flaps; and group 3, with osseocutaneous scapula flaps. Eighteen of 19 patients achieved a closed orbital reconstruction with restoration of the orbital aesthetic subunit. Among 16 patients with more than 4 months of follow-up, 10 patients had minimal or no resulting facial contour deformity and 8 patients engaged in social activities outside the home on a frequent basis. Five of the nine patients who were working before their surgery were able to return to work. Patients with complex midface defects involving the orbit can undergo free tissue transfer and have successful restoration of the native orbital aesthetic subunit without an orbital prosthesis.

  17. Application of orbital strong magnet in the extraction of deep orbital magnetic foreign bodies

    Directory of Open Access Journals (Sweden)

    Jin-Chen Jia

    2017-12-01

    Full Text Available AIM: To investigate the surgical method and efficacy of extraction of deep orbital magnetic foreign bodies by mean of an orbital strong magnet. METHODS: A retrospective analysis of clinical data of patients with deep orbital magnetic foreign bodies(OMFBin Hebei Eye Hospital from June 2014 to May 2017 was processed. A total of 23 eyes were enrolled, among them, 14 eyes of extraorbital OMFB, 9 eyes of intraorbital OMFB. The rate of extraction of foreign bodies and the postoperative complications were observed. RESULTS: All eyes of intraorbital foreign bodies were successfully extracted with 100% success rate. Twelve of 14 eyes of extraorbital foreign bodies were extracted with 86% success rate. Mild orbital hemorrhage were found in 2 eyes. There was no other obvious complication such as visual loss, orbital massive hemorrhage or limited ocular movement. CONCLUSION: It's an ideal surgical method to extract the deep orbital magnetic foreign bodies by mean of an orbital strong magnet, with mini-injury, high success rate, short duration and few complications.

  18. The Coupled Orbit-Attitude Dynamics and Control of Electric Sail in Displaced Solar Orbits

    Directory of Open Access Journals (Sweden)

    Mingying Huo

    2017-01-01

    Full Text Available Displaced solar orbits for spacecraft propelled by electric sails are investigated. Since the propulsive thrust is induced by the sail attitude, the orbital and attitude dynamics of electric-sail-based spacecraft are coupled and required to be investigated together. However, the coupled dynamics and control of electric sails have not been discussed in most published literatures. In this paper, the equilibrium point of the coupled dynamical system in displaced orbit is obtained, and its stability is analyzed through a linearization. The results of stability analysis show that only some of the orbits are marginally stable. For unstable displaced orbits, linear quadratic regulator is employed to control the coupled attitude-orbit system. Numerical simulations show that the proposed strategy can control the coupled system and a small torque can stabilize both the attitude and orbit. In order to generate the control force and torque, the voltage distribution problem is studied in an optimal framework. The numerical results show that the control force and torque of electric sail can be realized by adjusting the voltage distribution of charged tethers.

  19. Low-Cost 3D Printing Orbital Implant Templates in Secondary Orbital Reconstructions.

    Science.gov (United States)

    Callahan, Alison B; Campbell, Ashley A; Petris, Carisa; Kazim, Michael

    Despite its increasing use in craniofacial reconstructions, three-dimensional (3D) printing of customized orbital implants has not been widely adopted. Limitations include the cost of 3D printers able to print in a biocompatible material suitable for implantation in the orbit and the breadth of available implant materials. The authors report the technique of low-cost 3D printing of orbital implant templates used in complex, often secondary, orbital reconstructions. A retrospective case series of 5 orbital reconstructions utilizing a technique of 3D printed orbital implant templates is presented. Each patient's Digital Imaging and Communications in Medicine data were uploaded and processed to create 3D renderings upon which a customized implant was designed and sent electronically to printers open for student use at our affiliated institutions. The mock implants were sterilized and used intraoperatively as a stencil and mold. The final implant material was chosen by the surgeons based on the requirements of the case. Five orbital reconstructions were performed with this technique: 3 tumor reconstructions and 2 orbital fractures. Four of the 5 cases were secondary reconstructions. Molded Medpor Titan (Stryker, Kalamazoo, MI) implants were used in 4 cases and titanium mesh in 1 case. The stenciled and molded implants were adjusted no more than 2 times before anchored in place (mean 1). No case underwent further revision. The technique and cases presented demonstrate 1) the feasibility and accessibility of low-cost, independent use of 3D printing technology to fashion patient-specific implants in orbital reconstructions, 2) the ability to apply this technology to the surgeon's preference of any routinely implantable material, and 3) the utility of this technique in complex, secondary reconstructions.

  20. NEAR MAG DATA FOR EROS/ORBIT

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the NEAR magnetometer (MAG) data for the EROS/ORBIT phase. The data set begins on 2000-01-11T00:00:00.000 and ends 2001-02-12T23:59:59.999 ....

  1. Orbital current mode in elliptical quantum dots

    Science.gov (United States)

    Serra, Llorenç; Puente, Antonio; Lipparini, Enrico

    1999-11-01

    An orbital current mode peculiar to deformed quantum dots is theoretically investigated; first by using a simple model that makes it possible to analytically interpret its main characteristics, and second, by numerically solving the microscopic equations of time evolution after an initial perturbation within the time-dependent local-spin-density approximation. Results for different deformations and sizes are shown.

  2. Third-generation muffin–tin orbitals

    Indian Academy of Sciences (India)

    Unknown

    generation muffin–tin orbi- tals (MTOs) are. We demonstrate that they can be downfolded to smaller and smaller basis sets: sp3d10, sp3, and bond orbitals. For isolated bands, it is possible to generate Wannier functions a priori. Also for bands,.

  3. Surgical timing of the orbital "blowout" fracture

    DEFF Research Database (Denmark)

    Damgaard, Olaf Ehlers; Larsen, Christian Grønhøj; Felding, Ulrik Ascanius

    2016-01-01

    Objective: The orbital blowout fracture is a common facial injury, carrying with it a risk of visual impairment and undesirable cosmetic results unless treated properly. Optimal timing of the surgical treatment is still a matter of debate. We set out to determine whether a meta-analysis would bri...

  4. Orbital debris removal and meteoroid deflection

    Science.gov (United States)

    Campbell, Jonathan W.; Taylor, Charles R.; Smalley, Larry L.; Dickerson, Thomas

    1998-11-01

    Orbital debris in low-Earth orbit in the size range from 1 to 10 cm in diameter can be detected but not tracked reliably enough to be avoided by spacecraft. It can cause catastrophic damage even to a shielded spacecraft. With adaptive optics, a ground-based pulsed laser ablating the debris surface can produce enough propulsion in several hundred pulses to cause such debris to reenter the atmosphere. A single laser station could remove all of the 1 - 10 cm debris in three years or less. A technology demonstration of laser space propulsion is proposed which would pave the way for the implementation of such a debris removal system. The cost of the proposed demonstration is comparable with the estimated annual cost of spacecraft operations in the present orbital debris environment. Orbital debris is not the only space junk that is deleterious to the Earth's environment. Collisions with asteroids have caused major havoc to the Earth's biosphere many times in the ancient past. Since the possibility still exists for major impacts of asteroids with the Earth, it shown that it is possible to scale up the systems to prevent these catastrophic collisions providing sufficient early warning is available from new generation space telescopes plus deep space radar tracking.

  5. Mars Environment and Magnetic Orbiter model payload

    DEFF Research Database (Denmark)

    Langlais, B.; Leblanc, F.; Fouchet, T.

    2009-01-01

    Mars Environment and Magnetic Orbiter was proposed as an answer to the Cosmic Vision Call of Opportunity as a M-class mission. The MEMO mission is designed to study the strong interconnections between the planetary interior, atmosphere and solar conditions essential to understand planetary...

  6. Optimal Orbit Maneuvers with Electrodynamic Tethers

    Science.gov (United States)

    2006-06-01

    materials ( Dyneema , T T pecially with regard to the feasible set of maneuve 42 Eric L. M. Lanoix, Arun...Kevlar and Dyneema suffered 3-5 mm penetrations. The 1 mm strands of Kevlar and Dyneema would lasts only days in orbit, while the 0.3 mm strands of e

  7. Mars Telecom Orbiter mission operations concepts

    Science.gov (United States)

    Deutsch, Marie-Jose; Komarek, Tom; Lopez, Saturnino; Townes, Steve; Synnott, Steve; Austin, Richard; Guinn, Joe; Varghese, Phil; Edwards, Bernard; Bondurant, Roy; hide

    2004-01-01

    The Mars Telecom Orbiter (MTO) relay capability enables next decadal missions at Mars, collecting gigabits of data a day to be relayed back at speeds exceeding 4 Mbps and it facilitates small missions whose limited resources do not permit them to have a direct link to Earth.

  8. PROSTHETICS IN CANCER PATIENTS WITH ORBITAL DEFECTS

    Directory of Open Access Journals (Sweden)

    A. A. Kulakov

    2012-01-01

    Full Text Available Orthopedic treatment was performed in 53 patients with postoperative defects in the orbital area during 1969–2012. The developed practical guidelines could improve the cosmetic aspects of ectoprostheses, their fixation, and quality of life in the patients.

  9. Orbital Evolution of Jupiter-family Comets

    Science.gov (United States)

    Ipatov, S. I.; Mather, J. C.

    2004-05-01

    The orbital evolution of more than 25,000 Jupiter-family comets (JFCs) under the gravitational influence of planets was studied. After 40 Myr one considered object (with initial orbit close to that of Comet 88P) got aphelion distance Q1.4 AU, Qprobability of a collision of one of such objects, which move for millions of years inside Jupiter's orbit, with a terrestrial planet can be greater than analogous total probability for thousands other objects. Results obtained by the Bulirsch-Stoer method and by a symplectic method were mainly similar (except for probabilities of close encounters with the Sun when they were high). Our results show that the trans-Neptunian belt can provide a significant portion of NEOs, or the number of trans-Neptunian objects migrating inside solar system could be smaller than it was earlier considered, or most of 1-km former trans-Neptunian objects that had got NEO orbits disintegrated into mini-comets and dust during a smaller part of their dynamical lifetimes if these lifetimes are not small. The obtained results show that during the accumulation of the giant planets the total mass of icy bodies delivered to the Earth could be about the mass of water in Earth's oceans. Several our papers on this problem were put in http://arXiv.org/format/astro-ph/ (e.g., 0305519, 0308448). This work was supported by NASA (NAG5-10776) and INTAS (00-240).

  10. Orbits of linear operators tending to infinity

    Czech Academy of Sciences Publication Activity Database

    Müller, Vladimír; Vršovský, Jan

    2009-01-01

    Roč. 39, č. 1 (2009), s. 219-230 ISSN 0035-7596 R&D Projects: GA ČR(CZ) GA201/06/0128 Institutional research plan: CEZ:AV0Z10190503 Keywords : orbits of operators * plank problem Subject RIV: BA - General Mathematics Impact factor: 0.260, year: 2009

  11. CT findings of orbital inflammatory diseases

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jang Min; Shin, Hyun Joon; Kim, Jung Hyuk; Suh, Won Hyuck [College of Medicine, Korea University, Seoul (Korea, Republic of)

    1991-09-15

    Twenty-nine patients with orbital inflammatory disease (OIDs) were retrospectively reviewed in order to analyze detailed CT findings which might aid in differentiating OIDs. This study comprised 18 pseudotumors, 5 thyroid ophthalmopathies, and 6 cases of orbital cellulitis. CT scans of the pseudotumors showed various findings such as exophthalmos, scleritis, myositis of the extraocular muscle (MOM), and bone lesion. Bone lesions of the pseudo tumors, which have been rarely reported, were present in 7 cases in our series. Bilateral exophthalmos, myositis, and retrobulbar fat deposition were readily detected by CT in thyroid ophthalmopathy, and, in addition, we found bone erosions involving the orbital apices in 2 cases. In orbital cellulitis, extraorbital soft tissue swelling and lateral displacement of the medial rectus muscle in cases with ethmoiditis were the most conspicuous features. In summary, because of the overlapping CT findings in OIDs, careful examination of CT findings regarding the mode of EOM involvement and the presence or absence of scleritis or sinusitis might help narrow down the differential diagnosis. A pseudotumor with bone lesions could be mistaken as a malignant lesion, and therefore it is necessary to correlate clinical features with CT findings for an accurate diagnosis.

  12. Role of oral corticosteroids in orbital cellulitis.

    Science.gov (United States)

    Pushker, Neelam; Tejwani, Lalit Kumar; Bajaj, Mandeep S; Khurana, Saurbhi; Velpandian, Thirumurthy; Chandra, Mahesh

    2013-07-01

    To evaluate the role of oral corticosteroids as an anti-inflammatory adjunct in the treatment of orbital cellulitis. Prospective, comparative, single-masked, interventional clinical study. setting: Tertiary eye care center (All India Institute of Medical Sciences). study population: Patients with acute onset (within 14 days) of orbital cellulitis with or without abscess. intervention: Patients were randomized into 2 groups in the ratio of 1:2. Both groups received initial intravenous antibiotics. In Group 2, oral steroids were added after an initial response to intravenous antibiotics. main outcome measures: Resolution of signs and symptoms, duration of intravenous antibiotics, length of hospital stay, and sequelae of disease (ptosis, proptosis, and movement restriction) were evaluated and compared between the 2 groups. A total of 21 patients (age range, 11-59 years) with orbital cellulitis were studied. There were 7 patients in Group 1, who received standard intravenous antibiotics, and 14 in Group 2, who received adjuvant steroids. Patients in Group 2 showed an earlier resolution of inflammation in terms of periorbital edema (P = .002 at day 7), conjunctival chemosis (P orbital cellulitis may hasten resolution of inflammation with a low risk of exacerbating infection. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Stochastic Orbit Prediction Using KAM Tori

    Science.gov (United States)

    2011-03-24

    Implications .........................................................................................................3 1.4 State-of-the- Art ...21 2.1.2.4 Specific Mechanical Energy or Vis- Viva Equation ...............22 Kepler’s Equation...the- Art The current state-of-the- art for orbit propagation can be divided into three main branches: numerical (also called special perturbations

  14. Guidance trajectories for aeroassisted orbital transfer

    Science.gov (United States)

    Miele, A.

    1990-01-01

    Research on aerobraking guidance schemes is presented. The intent is to produce aerobraking guidance trajectories exhibiting many of the desirable characteristics of optimal aerobraking trajectories. Both one-control schemes and two-control schemes are studied. The research is in the interest of aeroassisted flight experiment vehicles (AFE) and aeroassisted orbital transfer (AOT) vehicles.

  15. Lunar flyby transfers between libration point orbits

    Science.gov (United States)

    Qi, Yi; Xu, Shijie; Qi, Rui

    2017-06-01

    Lunar flyby or lunar gravity assist is a classical technique to change the energy and trajectory of space vehicle in space mission. In this paper, lunar flyby transfers between Sun-Earth/Moon libration point orbits with different energies are investigated in the Sun-Earth-Moon restricted four-body problem. Distinguished by behaviours before and after lunar flyby, classification of lunar flyby orbits is defined and studied. Research indicates that junction point of special regions of four types of lunar flyby orbits denotes the perilune of lunar flyby transfer between libration point orbits. Based on those special perilunes, retrograde and prograde lunar flyby transfers are discussed in detail, respectively. The mean energy level transition distribution is proposed and applied to analyse the influence of phase angle and eccentricity on lunar flyby transfers. The phase space is divided into normal and chaotic intervals based on the topology pattern of transfers. A continuation strategy of lunar flyby transfer in the bicircular model is presented. Numerical examples show that compared with the single-impulse transfers based on patched invariant manifolds, lunar flyby transfers are more energy efficient. Finally, lunar flyby transfers are further extended to the realistic models.

  16. 1. Why Planetary Orbits are Closed

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 12. Planetary Orbits as Simple Harmonic Motion. Bikram Phookun. Classroom Volume 8 Issue 12 December 2003 pp 83-91. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/12/0083-0091 ...

  17. Orbital MALT Lymphoma: A Case Report

    Directory of Open Access Journals (Sweden)

    Shobha G Pai

    2004-08-01

    Full Text Available A case of orbital MALT (mucous associated lymphoid tissue lymphoma is reported for its rarity. It presented as a large tumor obscuring the whole eye with loss of vision, without any signs of dissemination and remained free of recurrence or metastasis 12 months after undergoing simple surgical excision.

  18. Rhinoscleroma with orbital extension: CT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Le Hir, P. [Department of Radiology, CHU Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, F-75012 Paris (France); Marsot-Dupuch, K. [Department of Radiology, CHU Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, F-75012 Paris (France); Bigel, P. [Department of Pathology, CHU Saint-Antoine, Paris (France); Elbigourmie, T.M. [Department of Radiology, CHU Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, F-75012 Paris (France); Jacquier, I. [ENT Department, CHU Saint-Antoine, Paris (France); Brunereau, L. [Department of Radiology, CHU Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, F-75012 Paris (France); Tubiana, J.M. [Department of Radiology, CHU Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, F-75012 Paris (France)

    1996-02-01

    We describe the MRI features of a rhinoscleroma with orbital extension. This benign bacterial and granulomatous lesion of the paranasal sinuses gave homogeneous low intensity on T2-weighted images and enhanced with gadolinium. It could simulate a malignant sinonasal tumour or a fungal sinusitis; the diagnosis must be considered in patients from endemic areas. (orig.). With 3 figs.

  19. From Slater orbitals to Coulomb Sturmians

    Indian Academy of Sciences (India)

    principal quantum number, respectively. Hydrogenoid orbitals span an orthonormal basis set of the Hilbert space that contains the ... variable N spans the continuum. Continuum basis sets imply inextricable mathe- .... polynomials, it is necessary to pay attention to the different notations in mathematical and quantum chem-.

  20. NIAC Phase II Orbiting Rainbows Granular Imager

    Science.gov (United States)

    Basinger, Scott A.; Palacios, David; Quadrelli, Marco B.; Swartzlander, Grover A., Jr.; Peng, XiaoPeng; Artusio, Alexandra; Arumugam, Darmin D.

    2015-01-01

    In this paper, we present some ideas regarding the optics and imaging aspects of granular spacecraft. Granular spacecraft are complex systems composed of a spatially disordered distribution of a large number of elements, for instance a cloud of grains in orbit. An example of application is a spaceborne observatory for exoplanet imaging, where the primary aperture is a cloud instead of a monolithic aperture.

  1. Management of orbital fractures: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Boyette JR

    2015-11-01

    Full Text Available Jennings R Boyette,1 John D Pemberton,2 Juliana Bonilla-Velez1 1Department of Otolaryngology-Head and Neck Surgery, 2Department of Ophthalmology, University of Arkansas for Medical Sciences, Little Rock, AR, USA Abstract: Many specialists encounter and treat orbital fractures. The management of these fractures is often challenging due to the impact that they can have on vision. Acute treatment involves a thorough clinical examination and management of concomitant ocular injuries. The clinical and radiographic findings for each individual patient must then be analyzed for the need for surgical intervention. Deformity and vision impairment can occur from these injuries, and while surgery is intended to prevent these problems, it can also create them. Therefore, surgical approach and implant selection should be carefully considered. Accurate anatomic reconstruction requires complete assessment of fracture margins and proper implant contouring and positioning. The implementation of new technologies for implant shaping and intraoperative assessment of reconstruction will hopefully lead to improved patient outcomes. Keywords: orbital fracture, orbital blowout, orbital floor

  2. Research study: STS-1 Orbiter Descent

    Science.gov (United States)

    Hickey, J. S.

    1981-01-01

    The conversion of STS-1 orbiter descent data from AVE-SESAME contact programs to the REEDA system and the reduction of raw radiosonde data is summarized. A first difference program, contact data program, plot data program, and 30 second data program were developed. Six radiosonde soundings were taken. An example of the outputs of each of the programs is presented.

  3. Recalculated Orbits of 8 Double Stars

    Science.gov (United States)

    Olevic, D.; Popovic, G.; Jovanovic, P.

    The authors present new orbital elements for the following pairs: ADS 1227, ADS 3317, ADS 8128, ADS 8239, ADS 8242, ADS 8539, ADS 8949 and McA 61. Individual masses for these pairs are also calculated. For the pairs ADS 8128, ADS 8239, ADS 8539 and ADS 8949 calculated parallaxes are in accordance with the corresponding parallaxes of the Hipparchos Program.

  4. Shaft Center Orbit in Dynamically Loaded Bearings

    DEFF Research Database (Denmark)

    Klit, Peder

    2005-01-01

    The aim of this work is to demonstrate how to utilize the bearings damping coe±cients to estimate the orbit for a dynamically loaded journal bearing. The classical method for this analysis was developed by Booker in 1965 [1]and described further in 1972 [2]. Several authors have re¯ned this metho...

  5. Bilateral failure of adduction following orbital decompression.

    Science.gov (United States)

    Kinsella, F; Kyle, P; Stansfield, A

    1990-01-01

    We report a case of bilateral complete failure of adduction following bilateral translid antralethmoidal orbital decompression. We believe the probable mechanism is neuropraxia (temporary dysfunction) of the third cranial nerves' supply to the medial recti, owing to these nerves' occupying an anatomically abnormal position. Partial recovery of adduction occurred over the ensuing six months. Images PMID:2337551

  6. Three Orbital Burns to Molniya Orbit Via Shuttle_Centaur G Upper Stage

    Science.gov (United States)

    Williams, Craig H.

    2015-01-01

    An unclassified analytical trajectory design, performance, and mission study was done for the 1982 to 1986 joint National Aeronautics and Space Administration (NASA)-United States Air Force (USAF) Shuttle/Centaur G upper stage development program to send performance-demanding payloads to high orbits such as Molniya using an unconventional orbit transfer. This optimized three orbital burn transfer to Molniya orbit was compared to the then-baselined two burn transfer. The results of the three dimensional trajectory optimization performed include powered phase steering data and coast phase orbital element data. Time derivatives of the orbital elements as functions of thrust components were evaluated and used to explain the optimization's solution. Vehicle performance as a function of parking orbit inclination was given. Performance and orbital element data was provided for launch windows as functions of launch time. Ground track data was given for all burns and coasts including variation within the launch window. It was found that a Centaur with fully loaded propellant tanks could be flown from a 37 deg inclination low Earth parking orbit and achieve Molniya orbit with comparable performance to the baselined transfer which started from a 57 deg inclined orbit: 9,545 versus 9,552 lb of separated spacecraft weight, respectively. There was a significant reduction in the need for propellant launch time reserve for a 1 hr window: only 78 lb for the three burn transfer versus 320 lb for the two burn transfer. Conversely, this also meant that longer launch windows over more orbital revolutions could be done for the same amount of propellant reserve. There was no practical difference in ground tracking station or airborne assets needed to secure telemetric data, even though the geometric locations of the burns varied considerably. There was a significant adverse increase in total mission elapsed time for the three versus two burn transfer (12 vs. 1-1/4 hr), but could be

  7. Three Orbital Burns to Molniya Orbit via Shuttle Centaur G Upper Stage

    Science.gov (United States)

    Williams, Craig H.

    2014-01-01

    An unclassified analytical trajectory design, performance, and mission study was done for the 1982-86 joint NASA-USAF Shuttle/Centaur G upper stage development program to send performance-demanding payloads to high orbits such as Molniya using an unconventional orbit transfer. This optimized three orbital burn transfer to Molniya orbit was compared to the then-baselined two burn transfer. The results of the three dimensional trajectory optimization performed include powered phase steering data and coast phase orbital element data. Time derivatives of the orbital elements as functions of thrust components were evaluated and used to explain the optimization's solution. Vehicle performance as a function of parking orbit inclination was given. Performance and orbital element data was provided for launch windows as functions of launch time. Ground track data was given for all burns and coasts including variation within the launch window. It was found that a Centaur with fully loaded propellant tanks could be flown from a 37deg inclination low Earth parking orbit and achieve Molniya orbit with comparable performance to the baselined transfer which started from a 57deg inclined orbit: 9,545 lb vs. 9,552 lb of separated spacecraft weight respectively. There was a significant reduction in the need for propellant launch time reserve for a one hour window: only 78 lb for the three burn transfer vs. 320 lb for the two burn transfer. Conversely, this also meant that longer launch windows over more orbital revolutions could be done for the same amount of propellant reserve. There was no practical difference in ground tracking station or airborne assets needed to secure telemetric data, even though the geometric locations of the burns varied considerably. There was a significant adverse increase in total mission elapsed time for the three vs. two burn transfer (12 vs. 11/4 hrs), but could be accommodated by modest modifications to Centaur systems. Future applications were

  8. An Overview of the Jupiter Europa Orbiter Concept's Europa Science Phase Orbit Design

    Science.gov (United States)

    Lock, Robert E.; Ludwinski, Jan M.; Petropoulos, Anastassios E.; Clark, Karla B.; Pappalardo, Robert T.

    2009-01-01

    Jupiter Europa Orbiter (JEO), the proposed NASA element of the proposed joint NASA-ESA Europa Jupiter System Mission (EJSM), could launch in February 2020 and conceivably arrive at Jupiter in December of 2025. The concept is to perform a multi-year study of Europa and the Jupiter system, including 30 months of Jupiter system science and a comprehensive Europa orbit phase of 9 months. This paper provides an overview of the JEO concept and describes the Europa Science phase orbit design and the related science priorities, model pay-load and operations scenarios needed to conduct the Europa Science phase. This overview is for planning and discussion purposes only.

  9. Canthal cutdown for emergent treatment of orbital compartment syndrome.

    Science.gov (United States)

    Strand, Andrew T; Czyz, Craig N; Gibson, Amanda

    2017-10-01

    This article evaluates the use of a "canthal cutdown" technique in orbital compartment syndrome in a cadaveric model. Twelve cadaver orbits were used to simulate orbital compartment syndrome using a blood analog solution. Two pressure probes, in different orbital locations, were used to monitor orbital pressure. Pressure was monitored during successive procedures: canthotomy, cantholysis, and canthal cutdown. Orbits were then re-injected with solution, simulating an active orbital hemorrhage, and pressure measurements were recorded over a 10-minute duration. No statistically significant difference was found between the two orbital pressure monitoring devices at each measurement point (p = 0.99). Significant pressure reductions, for both probes, were observed after canthal cutdown compared to initial measurement after injection of 20 mL blood analog (p compartment syndrome and temporizing treatment of compartment syndrome from active orbital hemorrhages.

  10. Orbital Architectures of Dynamically Complex Exoplanet Systems

    Science.gov (United States)

    Nelson, Benjamin E.

    2015-01-01

    The most powerful constraints on planet formation will come from characterizing the dynamical state of complex multi-planet systems. Unfortunately, with that complexity comes a number of factors that make analyzing these systems a computationally challenging endeavor: the sheer number of model parameters, a wonky shaped posterior distribution, and hundreds to thousands of time series measurements. We develop a differential evolution Markov chain Monte Carlo (RUN DMC) to tackle these difficult aspects of data analysis. We apply RUN DMC to two classic multi-planet systems from radial velocity surveys, 55 Cancri and GJ 876. For 55 Cancri, we find the inner-most planet "e" must be coplanar to within 40 degrees of the outer planets, otherwise Kozai-like perturbations will cause the planet's orbit to cross the stellar surface. We find the orbits of planets "b" and "c" are apsidally aligned and librating with low to median amplitude (50±610 degrees), but they are not orbiting in a mean-motion resonance. For GJ 876, we can meaningfully constrain the three-dimensional orbital architecture of all the planets based on the radial velocity data alone. By demanding orbital stability, we find the resonant planets have low mutual inclinations (Φ) so they must be roughly coplanar (Φcb = 1.41±0.620.57 degrees and Φbe = 3.87±1.991.86 degrees). The three-dimensional Laplace argument librates with an amplitude of 50.5±7.910.0 degrees, indicating significant past disk migration and ensuring long-term stability. These empirically derived models will provide new challenges for planet formation models and motivate the need for more sophisticated algorithms to analyze exoplanet data.

  11. Orbital Express fluid transfer demonstration system

    Science.gov (United States)

    Rotenberger, Scott; SooHoo, David; Abraham, Gabriel

    2008-04-01

    Propellant resupply of orbiting spacecraft is no longer in the realm of high risk development. The recently concluded Orbital Express (OE) mission included a fluid transfer demonstration that operated the hardware and control logic in space, bringing the Technology Readiness Level to a solid TRL 7 (demonstration of a system prototype in an operational environment). Orbital Express (funded by the Defense Advanced Research Projects Agency, DARPA) was launched aboard an Atlas-V rocket on March 9th, 2007. The mission had the objective of demonstrating technologies needed for routine servicing of spacecraft, namely autonomous rendezvous and docking, propellant resupply, and orbital replacement unit transfer. The demonstration system used two spacecraft. A servicing vehicle (ASTRO) performed multiple dockings with the client (NextSat) spacecraft, and performed a variety of propellant transfers in addition to exchanges of a battery and computer. The fluid transfer and propulsion system onboard ASTRO, in addition to providing the six degree-of-freedom (6 DOF) thruster system for rendezvous and docking, demonstrated autonomous transfer of monopropellant hydrazine to or from the NextSat spacecraft 15 times while on orbit. The fluid transfer system aboard the NextSat vehicle was designed to simulate a variety of client systems, including both blowdown pressurization and pressure regulated propulsion systems. The fluid transfer demonstrations started with a low level of autonomy, where ground controllers were allowed to review the status of the demonstration at numerous points before authorizing the next steps to be performed. The final transfers were performed at a full autonomy level where the ground authorized the start of a transfer sequence and then monitored data as the transfer proceeded. The major steps of a fluid transfer included the following: mate of the coupling, leak check of the coupling, venting of the coupling, priming of the coupling, fluid transfer, gauging

  12. Spin-Orbital Order Modified by Orbital Dilution in Transition-Metal Oxides: From Spin Defects to Frustrated Spins Polarizing Host Orbitals

    Directory of Open Access Journals (Sweden)

    Wojciech Brzezicki

    2015-03-01

    Full Text Available We investigate the changes in spin and orbital patterns induced by magnetic transition-metal ions without an orbital degree of freedom doped in a strongly correlated insulator with spin-orbital order. In this context, we study the 3d ion substitution in 4d transition-metal oxides in the case of 3d^{3} doping at either 3d^{2} or 4d^{4} sites, which realizes orbital dilution in a Mott insulator. Although we concentrate on this doping case as it is known experimentally and more challenging than other oxides due to finite spin-orbit coupling, the conclusions are more general. We derive the effective 3d−4d (or 3d−3d superexchange in a Mott insulator with different ionic valencies, underlining the emerging structure of the spin-orbital coupling between the impurity and the host sites, and demonstrate that it is qualitatively different from that encountered in the host itself. This derivation shows that the interaction between the host and the impurity depends in a crucial way on the type of doubly occupied t_{2g} orbital. One finds that in some cases, due to the quench of the orbital degree of freedom at the 3d impurity, the spin and orbital order within the host is drastically modified by doping. The impurity either acts as a spin defect accompanied by an orbital vacancy in the spin-orbital structure when the host-impurity coupling is weak or favors doubly occupied active orbitals (orbital polarons along the 3d−4d bond leading to antiferromagnetic or ferromagnetic spin coupling. This competition between different magnetic couplings leads to quite different ground states. In particular, for the case of a finite and periodic 3d atom substitution, it leads to striped patterns either with alternating ferromagnetic or antiferromagnetic domains or with islands of saturated ferromagnetic order. We find that magnetic frustration and spin degeneracy can be lifted by the quantum orbital flips of the host, but they are robust in special regions of the

  13. Mafic sill/dykes intruding into late Maastrichtian-early Paleocene calciclastic units, NE-Turkey: Petrographical and geochemical features of latest magmatic activity before collision in the eastern Sakarya zone

    Science.gov (United States)

    Aydin, Faruk; Oǧuz, Simge; Karsli, Orhan; Kandemir, Raif; Şen, Cüneyt; Uysal, İbrahim

    2017-04-01

    We present here new petrographical, mineralogical and whole-rock geochemical data for mafic sill/dykes intruding into late Maastrichtian-early Paleocene calciclastic units in the Düzköy (Trabzon) and Cankurtaran (Artvin) areas (NE Turkey) of the eastern Sakarya zone (ESZ) in order to decipher the latest magmatic activity in the final stage of subduction-related magmatism of the ESZ. U-Pb zircon dating for the mafic sill/dykes in the region yielded ages varying from 83.6 to 78.5Ma (i.e. Early Campanian). Mafic sill/dykes consist of mostly basalts and lesser basaltic-andesites with komatiitic basalts. Most of the dyke samples display aphyric to porphyritic texture with phenocrysts of plagioclase (mostly replaced by calcite), clinopyroxene (partly uralized), olivine (almost serpentinized), and amphibole (partly chloritized). Based on the MgO, Nb and Zr contents with Nb/Y ratio, the mafic dykes from Düzköy area are mainly classified as two subgroups (basalts and basaltic andesites) while those of Cankurtaran can be divided into three different groups (low- and high-Nb normal basalts and komatitic basalts). Düzköy basaltic dykes have higher MgO (3.8-7.8%) and lower Nb (3-4ppm) and Zr (53-62ppm) contents with Nb/Y ratio (˜0.2) than those of Düzköy basaltic-andesitic dykes (MgO: ˜1.8%, Nb: 6-15ppm, Zr: 106-145ppm, Nb/Y: 0.3-0.6). On the other hand, Cankurtaran mafic sill/dykes have relatively high MgO contents (˜4-20%). These sill/dykes with 15-20% of MgO and contents are called as komatiitic basalt which has relatively low K2O (contents with Nb/Y ratio (˜0.1-0.2). However, normal basalts from Cankurtaran have quite lower MgO contents (˜4-9%) than that of the komatiitic basalt. Also, they can be divided into two subgroups in terms of MgO (5.7-8.7% for group 1 and 4.0-4.4% for group 2), Nb (3-14ppm for group 1 and 19-21ppm for group 2), Zr (94-111ppm for group 1 and 125-140ppm for group 2) contents, and Nb/Y ratio (˜0.2-0.8 for group 1 and (˜1.0-1.2 for

  14. Orbit Design Based on the Global Maps of Telecom Metrics

    Science.gov (United States)

    Lee, Charles H.; Cheung, Kar-Ming; Edwards, Chad; Noreen, Gary K.; Vaisnys, Arvydas

    2004-01-01

    In this paper we describe an orbit design aide tool, called Telecom Orbit Analysis and Simulation Tool(TOAST). Although it can be used for studying and selecting orbits for any planet, we solely concentrate on its use for Mars. By specifying the six orbital elements for an orbit, a time frame of interest, a horizon mask angle, and some telecom parameters such as the transmitting power, frequency, antenna gains, antenna losses, link margin, received threshold powers for the rates, etc. this tool enables the user to view the animation of the orbit in two and three-dimensional different telecom metrics at any point on the Mars, namely the global planetary map.

  15. Approximate State Transition Matrix and Secular Orbit Model

    Directory of Open Access Journals (Sweden)

    M. P. Ramachandran

    2015-01-01

    Full Text Available The state transition matrix (STM is a part of the onboard orbit determination system. It is used to control the satellite’s orbital motion to a predefined reference orbit. Firstly in this paper a simple orbit model that captures the secular behavior of the orbital motion in the presence of all perturbation forces is derived. Next, an approximate STM to match the secular effects in the orbit due to oblate earth effect and later in the presence of all perturbation forces is derived. Numerical experiments are provided for illustration.

  16. Orbit Determination of Spacecraft in Earth-Moon L1 and L2 Libration Point Orbits

    Science.gov (United States)

    Woodard, Mark; Cosgrove, Daniel; Morinelli, Patrick; Marchese, Jeff; Owens, Brandon; Folta, David

    2011-01-01

    The ARTEMIS mission, part of the THEMIS extended mission, is the first to fly spacecraft in the Earth-Moon Lissajous regions. In 2009, two of the five THEMIS spacecraft were redeployed from Earth-centered orbits to arrive in Earth-Moon Lissajous orbits in late 2010. Starting in August 2010, the ARTEMIS P1 spacecraft executed numerous stationkeeping maneuvers, initially maintaining a lunar L2 Lissajous orbit before transitioning into a lunar L1 orbit. The ARTEMIS P2 spacecraft entered a L1 Lissajous orbit in October 2010. In April 2011, both ARTEMIS spacecraft will suspend Lissajous stationkeeping and will be maneuvered into lunar orbits. The success of the ARTEMIS mission has allowed the science team to gather unprecedented magnetospheric measurements in the lunar Lissajous regions. In order to effectively perform lunar Lissajous stationkeeping maneuvers, the ARTEMIS operations team has provided orbit determination solutions with typical accuracies on the order of 0.1 km in position and 0.1 cm/s in velocity. The ARTEMIS team utilizes the Goddard Trajectory Determination System (GTDS), using a batch least squares method, to process range and Doppler tracking measurements from the NASA Deep Space Network (DSN), Berkeley Ground Station (BGS), Merritt Island (MILA) station, and United Space Network (USN). The team has also investigated processing of the same tracking data measurements using the Orbit Determination Tool Kit (ODTK) software, which uses an extended Kalman filter and recursive smoother to estimate the orbit. The orbit determination results from each of these methods will be presented and we will discuss the advantages and disadvantages associated with using each method in the lunar Lissajous regions. Orbit determination accuracy is dependent on both the quality and quantity of tracking measurements, fidelity of the orbit force models, and the estimation techniques used. Prior to Lissajous operations, the team determined the appropriate quantity of tracking

  17. A Survey and Performance Analysis of Orbit Propagators for LEO, GEO, and Highly Elliptical Orbits

    Science.gov (United States)

    Shuster, Simon P.

    On-orbit targeting, guidance, and navigation relies on state vector propagation algorithms that must strike a balance between accuracy and computational efficiency. To better understand this balance, the relative position accuracy and computational requirements of numerical and analytical propagation methods are analyzed for a variety of orbits. For numerical propagation, several differential equation formulations (Cowell, Encke-time, Encke-beta, and Equinoctial Elements) are compared over a range of integration step sizes for a given set of perturbations and numerical integration methods. This comparison is repeated for two numerical integrators: a Runge-Kutta 4th order and a NLZD4/4. For analytical propagation, SGP4, which relies on mean orbital elements, is compared for element sets averaged with different amounts of orbit data.

  18. Frozen orbits at high eccentricity and inclination: application to Mercury orbiter

    Science.gov (United States)

    Delsate, N.; Robutel, P.; Lemaître, A.; Carletti, T.

    2010-11-01

    We hereby study the stability of a massless probe orbiting around an oblate central body (planet or planetary satellite) perturbed by a third body, assumed to lay in the equatorial plane (Sun or Jupiter for example) using a Hamiltonian formalism. We are able to determine, in the parameters space, the location of the frozen orbits, namely orbits whose orbital elements remain constant on average, to characterize their stability/unstability and to compute the periods of the equilibria. The proposed theory is general enough, to be applied to a wide range of probes around planet or natural planetary satellites. The BepiColombo mission is used to motivate our analysis and to provide specific numerical data to check our analytical results. Finally, we also bring to the light that the coefficient J 2 is able to protect against the increasing of the eccentricity due to the Kozai-Lidov effect and the coefficient J 3 determines a shift of the equilibria.

  19. Recurrent Orbital Inflammation Mimicking Orbital Cellulitis Associated With Orbitopalpebral Venous Lymphatic Malformation.

    Science.gov (United States)

    Galindo-Ferreiro, Alicia; Alkatan, Hind M; ElKhamary, Sahar M; AlDosairi, Saif; Cruz, A Augusto V

    An 8-year-old boy initially presented with an orbitopalpebral mass diagnosed clinically and radiologically as a low-flow diffuse venous lymphatic malformation involving the left upper eyelid and orbit. Over 8 months of follow up, he had 2 acute episodes of severe orbital inflammation that warranted hospitalization and treatment with intravenous antibiotic, steroids and surgical debulking. After a third surgical excision, the lesion remained clinically stable.

  20. Precise halo orbit design and optimal transfer to halo orbits from earth using differential evolution

    Science.gov (United States)

    Nath, Pranav; Ramanan, R. V.

    2016-01-01

    The mission design to a halo orbit around the libration points from Earth involves two important steps. In the first step, we design a halo orbit for a specified size and in the second step, we obtain an optimal transfer trajectory design to the halo orbit from an Earth parking orbit. Conventionally, the preliminary design for these steps is obtained using higher order analytical solution and the dynamical systems theory respectively. Refinements of the design are carried out using gradient based methods such as differential correction and pseudo arc length continuation method under the of circular restricted three body model. In this paper, alternative single level schemes are developed for both of these steps based on differential evolution, an evolutionary optimization technique. The differential evolution based scheme for halo orbit design produces precise halo orbit design avoiding the refinement steps. Further, in this approach, prior knowledge of higher order analytical solutions for the halo orbit design is not needed. The differential evolution based scheme for the transfer trajectory, identifies the precise location on the halo orbit that needs minimum energy for insertion and avoids exploration of multiple points. The need of a close guess is removed because the present scheme operates on a set of bounds for the unknowns. The constraint on the closest approach altitude from Earth is handled through objective function. The use of these schemes as the design and analysis tools within the of circular restricted three body model is demonstrated through case studies for missions to the first libration point of Sun-Earth system.

  1. Efficient methods for determining precise orbits of low Earth orbiters using the Global Positioning System

    Science.gov (United States)

    Bock, Heike

    The main part of this work dealt with the development and evaluation of efficient methods for precise orbit determination of LEOs. A kinematic approach using GPS zero-difference observations was developed (program LEOKIN) and a procedure for generation of dynamic and reduced-dynamic orbits was presented (program SATORB). The procedures have been tested using long GPS data series gathered by two LEO satellites, namely CHAMP and SAC-C. An external comparison was available for the time interval of the eleven days of the IGS CHAMP test campaign (May 20 to 30, 2001). The orbit solution generated at the Technical University of Munich (TUM), Germany, using the Bernese GPS Software was used for this purpose. The TUM-solution is believed to be one of the best solutions contributing to the IGS test campaign. Comparisons with this solution showed that both our best kinematic trajectory and a post-fit reduced-dynamic orbit based on this kinematic solution compare within an RMS error per coordinate (of a Helmert transformation) of about 10 cm with the TUM-solutions. This indicates that LEO orbits with a quality of about 10 cm result from our analyses. The goal of developing efficient methods for precise orbit determination of LEOs is therefore achieved with the zero-difference kinematic point positioning procedure in LEOKIN and the program SATORB to generate reduced-dynamic orbits. It is worth mentioning that the procedure, when using only code observations as input, results in reduced-dynamic orbits with a qualitiy of already 30 cm RMS.

  2. Orbit determination by genetic algorithm and application to GEO observation

    Science.gov (United States)

    Hinagawa, Hideaki; Yamaoka, Hitoshi; Hanada, Toshiya

    2014-02-01

    This paper demonstrates an initial orbit determination method that solves the problem by a genetic algorithm using two well-known solutions for the Lambert's problem: universal variable method and Battin method. This paper also suggests an intuitive error evaluation method in terms of rotational angle and orbit shape by separating orbit elements into two groups. As reference orbit, mean orbit elements (original two-lines elements) and osculating orbit elements considering the J2 effect are adopted and compared. Our proposed orbit determination method has been tested with actual optical observations of a geosynchronous spacecraft. It should be noted that this demonstration of the orbit determination is limited to one test case. This observation was conducted during approximately 70 min on 2013/05/15 UT. Our method was compared with the orbit elements propagated by SGP4 using the TLE of the spacecraft. The result indicates that our proposed method had a slightly better performance on estimating orbit shape than Gauss's methods and Escobal's method by 120 km. In addition, the result of the rotational angle is closer to the osculating orbit elements than the mean orbit elements by 0.02°, which supports that the estimated orbit is valid.

  3. Spin Orbit Torque in Ferromagnetic Semiconductors

    KAUST Repository

    Li, Hang

    2016-06-21

    Electrons not only have charges but also have spin. By utilizing the electron spin, the energy consumption of electronic devices can be reduced, their size can be scaled down and the efficiency of `read\\' and `write\\' in memory devices can be significantly improved. Hence, the manipulation of electron spin in electronic devices becomes more and more appealing for the advancement of microelectronics. In spin-based devices, the manipulation of ferromagnetic order parameter using electrical currents is a very useful means for current-driven operation. Nowadays, most of magnetic memory devices are based on the so-called spin transfer torque, which stems from the spin angular momentum transfer between a spin-polarized current and the magnetic order parameter. Recently, a novel spin torque effect, exploiting spin-orbit coupling in non-centrosymmetric magnets, has attracted a massive amount of attention. This thesis addresses the nature of spin-orbit coupled transport and torques in non-centrosymmetric magnetic semiconductors. We start with the theoretical study of spin orbit torque in three dimensional ferromagnetic GaMnAs. Using the Kubo formula, we calculate both the current-driven field-like torque and anti-damping-like torque. We compare the numerical results with the analytical expressions in the model case of a magnetic Rashba two-dimensional electron gas. Parametric dependencies of the different torque components and similarities to the analytical results of the Rashba two-dimensional electron gas in the weak disorder limit are described. Subsequently we study spin-orbit torques in two dimensional hexagonal crystals such as graphene, silicene, germanene and stanene. In the presence of staggered potential and exchange field, the valley degeneracy can be lifted and we obtain a valley-dependent Berry curvature, leading to a tunable antidamping torque by controlling the valley degree of freedom. This thesis then addresses the influence of the quantum spin Hall

  4. On periodic orbits in discrete-time cascade systems

    Directory of Open Access Journals (Sweden)

    Huimin Li

    2006-01-01

    Full Text Available We present some results on existence, minimum period, number of periodic orbits, and stability of periodic orbits in discrete-time cascade systems. Some examples are presented to illustrate these results.

  5. Primary palpebral and orbital ossification in pseudo-pseudohypoparathyroidism

    DEFF Research Database (Denmark)

    Klauber, S.; Heegaard, S.; Prause, J.U.

    2002-01-01

    ophthalmology, Albright's heriditary osteodystrophy, ossification, pseudo-pseudohypoparathyroidism, pseodohypoparathyroidism, hypothyroidism, GNAS1 gene, history, eyelid, orbit......ophthalmology, Albright's heriditary osteodystrophy, ossification, pseudo-pseudohypoparathyroidism, pseodohypoparathyroidism, hypothyroidism, GNAS1 gene, history, eyelid, orbit...

  6. Quantitative assessment of orbital implant position - a proof of concept

    NARCIS (Netherlands)

    Schreurs, R.; Dubois, L.; Becking, A.G.; Maal, T.J.J.

    2016-01-01

    Introduction In orbital reconstruction, the optimal location of a predefined implant can be planned preoperatively. Surgical results can be assessed intraoperatively or postoperatively. A novel method for quantifying orbital implant position is introduced. The method measures predictability of

  7. Quantitative Assessment of Orbital Implant Position - A Proof of Concept

    NARCIS (Netherlands)

    Schreurs, R.; Dubois, L.; Becking, A.G.; Maal, T.J.J.

    2016-01-01

    INTRODUCTION: In orbital reconstruction, the optimal location of a predefined implant can be planned preoperatively. Surgical results can be assessed intraoperatively or postoperatively. A novel method for quantifying orbital implant position is introduced. The method measures predictability of

  8. Treatment of orbital inflammation with rituximab in Wegener's granulomatosis

    DEFF Research Database (Denmark)

    Baslund, Bo; Wiencke, Anne Katrine; Rasmussen, Niels

    2012-01-01

    To study the efficacy of rituximab therapy for the treatment of orbital inflammation in patients with Wegener's granulomatosis (WG).......To study the efficacy of rituximab therapy for the treatment of orbital inflammation in patients with Wegener's granulomatosis (WG)....

  9. Management of orbital complications of sinusitis in pediatric patients.

    Science.gov (United States)

    Kinis, Vefa; Ozbay, Musa; Bakir, Salih; Yorgancilar, Ediz; Gun, Ramazan; Akdag, Mehmet; Sahin, Muhammed; Topcu, Ismail

    2013-09-01

    The most common reason of orbital infections is sinusitis. Orbital complications of sinusitis are mostly seen in children. Loss of vision and intracranial infections are among the complications of sinusitis. Prompt diagnosis and treatment is very important in the management of orbital complications. The orbital complication can be in the form of cellulitis or abscess. A retrospective review of 26 pediatric patients with orbital complications due to sinusitis was presented in this study. Of 26 patients, there were 13 cases of preseptal cellulitis, 2 cases of orbital cellulitis, and 11 cases of subperiosteal abscess. We grouped the preseptal and orbital cellulites in one category and the subperiosteal abscess in the other. All patients in the cellulitis group recovered by medical treatment. All the patients were treated by surgical drainage. Early diagnosis and appropriate treatment method are vital for the treatment of orbital complications secondary to sinusitis.

  10. GALILEO ORBITER V POS VENUS TRAJECTORY V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — Galileo Orbiter 60 second sampled trajectory data from the Venus flyby in Venus Solar Orbital (VSO) coordinates. These data cover the interval 1990-02-09 00:00 to...

  11. Tropical sea surface temperatures and the earth's orbital eccentricity cycles

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, S.M.; Fernandes, A.A.; Mohan, R.

    cyclicities at ~100- and ~400-ka corresponding to the Earth's orbital eccentricity cycles. Results, therefore imply that the tropical Indian Ocean warm pool persisted during the Quaternary and the paleo-SSTs fluctuating at the orbital eccentricity frequencies...

  12. GPM GROUND VALIDATION SATELLITE SIMULATED ORBITS LPVEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Satellite Simulated Orbits LPVEx dataset is available in the Orbital database, which takes account for the atmospheric profiles, the...

  13. Fabrication of patient specific composite orbital floor implants by stereolithography

    NARCIS (Netherlands)

    Geven, Mike Alexander; Varjas, V.; Kamer, L.; Wang, X.; Peng, J.; Eglin, D.; Grijpma, Dirk W.

    2015-01-01

    Fractures of the orbital floor are common in traffic accidents and assaults, and inadequate treatment can result in serious complications. Accurate anatomical reconstruction of the orbit using implants is the preferred treatment. Implants require degradability, adequate mechanical properties to

  14. Sorting and quantifying orbital angular momentum of laser beams

    CSIR Research Space (South Africa)

    Schulze, C

    2013-10-01

    Full Text Available We present a novel tool for sorting the orbital angular momentum and to determine the orbital angular momentum density of laser beams, which is based on the use of correlation filters....

  15. NOAA Polar-orbiting Operational Environmental Satellites (POES) Radiometer Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Polar-orbiting Operational Environmental Satellite (POES) series offers the advantage of daily global coverage, by making nearly polar orbits 14 times per day...

  16. Earth view: A business guide to orbital remote sensing

    Science.gov (United States)

    Bishop, Peter C.

    1990-01-01

    The following subject areas are covered: Earth view - a guide to orbital remote sensing; current orbital remote sensing systems (LANDSAT, SPOT image, MOS-1, Soviet remote sensing systems); remote sensing satellite; and remote sensing organizations.

  17. Application of the ITD algorithm to Landsat orbital transient responses

    Science.gov (United States)

    Kauffman, R. R.

    1988-01-01

    The topics are presented in viewgraph form and include the following: Landsat 4 system description; five degree-of-freedom system example problem; orbital finite element model analysis; and measured orbital data analysis.

  18. On the theory of Killing orbits in spacetime

    Science.gov (United States)

    Hall, G. S.

    2003-09-01

    This paper gives a theoretical discussion of the orbits and isotropies which arise in a spacetime which admits a Lie algebra of Killing vector fields. The submanifold structure of the orbits is explored together with their induced Killing vector structure. A general decomposition of a spacetime in terms of the nature and dimension of its orbits is given and the concept of stability and instability for orbits introduced. A general relation is shown linking the dimensions of the Killing algebra, the orbits and the isotropies. The well-behaved nature of 'stable' orbits and the possible misbehaviour of the 'unstable' ones is pointed out and, in particular, the fact that independent Killing vector fields in spacetime may not induce independent Killing vector fields on unstable orbits. Several examples are presented to exhibit these features. Finally, an appendix is given which revisits and attempts to clarify the well-known theorem of Fubini on the dimension of Killing orbits.

  19. Lageos orbit and the albedo problem

    Science.gov (United States)

    Rubincam, D. P.

    1984-01-01

    The objective was to obtain an analytic expression for the radiation pressure force on a satellite due to sunlight reflected from the Earth. The Lageos satellite undergoes unexplained along-track accelerations. These accelerations are believed to be due mainly to terrestrial radiation pressure. The effect of sunlight reflected off the surface of the Earth must thus be modeled to insure an accurate orbit for Lageos. An accurate orbit is necessary for carrying out Lageos' mission of measuring tectonic plate motion, polar motion, and Earth rotation. The present investigation focuses on a spherical harmonic approach to the problem. An equation for the force was obtained by assuming the Earth's surface reflects sunlight according to Lambert's law. The equation is an integral over the whole Earth's surface. Expressions occurring inside the integral are expressed in terms of spherical harmonics. The problem is thus reduced to integrating products of spherical harmonics.

  20. Molecular orbital calculations using chemical graph theory

    CERN Document Server

    Dias, Jerry Ray

    1993-01-01

    Professor John D. Roberts published a highly readable book on Molecular Orbital Calculations directed toward chemists in 1962. That timely book is the model for this book. The audience this book is directed toward are senior undergraduate and beginning graduate students as well as practicing bench chemists who have a desire to develop conceptual tools for understanding chemical phenomena. Although, ab initio and more advanced semi-empirical MO methods are regarded as being more reliable than HMO in an absolute sense, there is good evidence that HMO provides reliable relative answers particularly when comparing related molecular species. Thus, HMO can be used to rationalize electronic structure in 1t-systems, aromaticity, and the shape use HMO to gain insight of simple molecular orbitals. Experimentalists still into subtle electronic interactions for interpretation of UV and photoelectron spectra. Herein, it will be shown that one can use graph theory to streamline their HMO computational efforts and to arrive...

  1. Spin-orbit-coupled quantum gases

    Science.gov (United States)

    Radic, Juraj

    The dissertation explores the effects of synthetic spin-orbit coupling on the behaviour of quantum gases in several different contexts. We first study realistic methods to create vortices in spin-orbit-coupled (SOC) Bose-Einstein condensates (BEC). We propose two different methods to induce thermodynamically stable static vortex configurations: (1) to rotate both the Raman lasers and the anisotropic trap; and (2) to impose a synthetic Abelian field on top of synthetic spin-orbit interactions. We solve the Gross-Pitaevskii equation for several experimentally relevant regimes and find new interesting effects such as spatial separation of left- and right-moving spin-orbit-coupled condensates, and the appearance of unusual vortex arrangements. Next we consider cold atoms in an optical lattice with synthetic SOC in the Mott-insulator regime. We calculate the parameters of the corresponding tight-binding model and derive the low-energy spin Hamiltonian which is a combination of Heisenberg model, quantum compass model and Dzyaloshinskii-Moriya interaction. We find that the Hamiltonian supports a rich classical phase diagram with collinear, spiral and vortex phases. Next we study the time evolution of the magnetization in a Rashba spin-orbit-coupled Fermi gas, starting from a fully-polarized initial state. We model the dynamics using a Boltzmann equation, which we solve in the Hartree-Fock approximation. The resulting non-linear system of equations gives rise to three distinct dynamical regimes controlled by the ratio of interaction and spin-orbit-coupling strength lambda: for small lambda, the magnetization decays to zero. For intermediate lambda, it displays undamped oscillations about zero and for large lambda, a partially magnetized state is dynamically stabilized. Motivated by an interesting stripe phase which appears in BEC with SOC [Li et al., Phys. Rev. Lett. 108, 225301 (2011)], we study the finite-temperature phase diagram of a pseudospin-1/2 Bose gas with

  2. Analytical model for orbital debris environmental management

    Science.gov (United States)

    Talent, David L.

    1990-01-01

    A differential equation, also referred to as the PIB (particle-in-a-box) model, expressing the time rate of change of the number of objects in orbit, is developed, and its applicability is illustrated. The model can be used as a tool for the assessment of LEO environment stability, and as a starting point for the development of numerical evolutionary models. Within the context of the model, evolutionary scenarios are examined, and found to be sensitive to the growth rate. It is determined that the present environment is slightly unstable to catastrophic growth, and that the number of particles on orbit will continue to increase until approximately 2250-2350 AD, with a maximum of 2,000,000. The model is expandable to the more realistic (complex) case of multiple species in a multiple-tier system.

  3. On the galactocentric orbits of nearby stars

    Directory of Open Access Journals (Sweden)

    Ninković S.

    1999-01-01

    Full Text Available Using the data from the Gliese-Jahreiss Catalogue and a particular form of the galactic potential the authors construct galactocentric orbits for nearby stars. The potential used in our paper is stationary and axially symmetric with three contributors - bulge, disc and dark corona. In the calculating of the galactocentric phase coordinates the distance of the Sun to the galactic plane is neglected, the asymmetric drift is not, whereas the components of the solar motion are varied; the distance of the Sun to the axis of galactic rotation and the corresponding value of the circular velocity are assumed according to the model used in the paper. The obtained orbits (projection on meridional plane in a vast majority are box-like, or more precisely trapezium-like. The effect of the assumed solar motion is discussed and comparisons with results obtained by applying different potentials and initial conditions are made.

  4. Optimal trajectories for aeroassisted orbital transfer

    Science.gov (United States)

    Miele, A.; Venkataraman, P.

    1983-01-01

    Consideration is given to classical and minimax problems involved in aeroassisted transfer from high earth orbit (HEO) to low earth orbit (LEO). The transfer is restricted to coplanar operation, with trajectory control effected by means of lift modulation. The performance of the maneuver is indexed to the energy expenditure or, alternatively, the time integral of the heating rate. Firist-order optimality conditions are defined for the classical approach, as are a sequential gradient-restoration algorithm and a combined gradient-restoration algorithm. Minimization techniques are presented for the aeroassisted transfer energy consumption and time-delay integral of the heating rate, as well as minimization of the pressure. It is shown that the eigenvalues of the Jacobian matrix of the differential system is both stiff and unstable, implying that the sequential gradient restoration algorithm in its present version is unsuitable. A new method, involving a multipoint approach to the two-poing boundary value problem, is recommended.

  5. Loops in the Sun’s orbit

    Directory of Open Access Journals (Sweden)

    Marjanov Milutin

    2013-01-01

    Full Text Available Besides translation, spin around its axis and rotation around center of the Milky Way, the Sun performs relative motion in the solar system Laplacian plane, also. This motion was anticipated by Newton himself, in his Principia. The form of the Sun’s orbit is substantially different from the other solar system bodies’ orbits. Namely, the Sun moves along the path composed of the chain of large and small loops [1, 2, 6, 9]. This chain is situated within the circular outline with the diameter approximately twice as large as the Sun’s is. Under supposition that the solar system is stable, the Sun is going to move along it, in the same region, for eternity, never reitereiting the same path. It was also shown in this work that velocity and acceleration of the Sun’s center of mass are completely defined by the relative velocities and accelerations of the planets with respect to the Sun.

  6. SEP Mission Design Space for Mars Orbiters

    Science.gov (United States)

    Woolley, Ryan C.; Nicholas, Austin K.

    2015-01-01

    The advancement of solar-electric propulsion (SEP) technologies and larger, light-weight solar arrays offer a tremendous advantage to Mars orbiters in terms of both mass and timeline flexibility. These advantages are multiplied for round-trip orbiters (e.g. potential Mars sample return) where a large total Delta V would be required. In this paper we investigate the mission design characteristics of mission concepts utilizing various combinations and types of SEP thrusters, solar arrays, launch vehicles, launch dates, arrival dates, etc. SEP allows for greater than 50% more mass delivered and launch windows of months to years. We also present the SEP analog to the ballistic Porkchop plot - the "Bacon" plot.

  7. Orbital Models and Electronic Structure Theory

    DEFF Research Database (Denmark)

    Linderberg, Jan

    2012-01-01

    This tribute to the work by Carl Johan Ballhausen focuses on the emergence of quantitative means for the study of the electronic properties of complexes and molecules. Development, refinement and application of the orbital picture elucidated electric and magnetic features of ranges of molecules w...... when used for the interpretation of electronic transitions, electron spin resonance parameters, rotatory dispersion, nuclear quadrupole couplings as well as geometric bonding patterns. Ballhausen's profound impact on the field cannot be overestimated.......This tribute to the work by Carl Johan Ballhausen focuses on the emergence of quantitative means for the study of the electronic properties of complexes and molecules. Development, refinement and application of the orbital picture elucidated electric and magnetic features of ranges of molecules...

  8. Orbital decompression for Graves' orbitopathy in England

    Science.gov (United States)

    Perros, P; Chandler, T; Dayan, C M; Dickinson, A J; Foley, P; Hickey, J; MacEwen, C J; Lazarus, J H; McLaren, J; Rose, G E; Uddin, J M; Vaidya, B

    2012-01-01

    Aims The purpose of this study was to obtain data on orbital decompression procedures performed in England, classed by hospital and locality, to evaluate regional variation in care. Methods Data on orbital decompression taking place in England over a 2-year period between 2007 and 2009 were derived from CHKS Ltd and analysed by the hospital and primary care trust. Results and conclusions In all, 44% of these operations took place in hospitals with an annual workload of 10 or fewer procedures. Analysis of the same data by primary care trust suggests an almost 30-fold variance in the rates of decompression performed per unit population. Expertise available to patients with Graves' orbitopathy and rates of referral for specialist care in England appears to vary significantly by geographic location. These data, along with other outcome measures, will provide a baseline by which progress can be judged. PMID:22157920

  9. Fuzzy logic in autonomous orbital operations

    Science.gov (United States)

    Lea, Robert N.; Jani, Yashvant

    1991-01-01

    Fuzzy logic can be used advantageously in autonomous orbital operations that require the capability of handling imprecise measurements from sensors. Several applications are underway to investigate fuzzy logic approaches and develop guidance and control algorithms for autonomous orbital operations. Translational as well as rotational control of a spacecraft have been demonstrated using space shuttle simulations. An approach to a camera tracking system has been developed to support proximity operations and traffic management around the Space Station Freedom. Pattern recognition and object identification algorithms currently under development will become part of this camera system at an appropriate level in the future. A concept to control environment and life support systems for large Lunar based crew quarters is also under development. Investigations in the area of reinforcement learning, utilizing neural networks, combined with a fuzzy logic controller, are planned as a joint project with the Ames Research Center.

  10. Flight Performance Handbook for Orbital Operations: Orbital Mechanics and Astrodynamics Formulae, Theorems, Techniques, and Applications

    Science.gov (United States)

    Ambrosio, Alphonso; Blitzer, Leon; Conte, S.D.; Cooper, Donald H.; Dergarabedian, P.; Dethlefsen, D.G.; Lunn, Richard L.; Ireland, Richard O.; Jensen, Arnold A.; Kang, Garfield; hide

    1961-01-01

    This handbook provides parametric data useful both to the space vehicle designer and mission analyst. It provides numerical and analytical relationships between missions and gross vehicle characteristics as a function of performance parameters. The effects of missile constraints and gross guidance limitations plus operational constraints such as launch site location, tracking net location, orbit visibility and mission on trajectory and orbit design parameters are exhibited. The influence of state-of- the-art applications of solar power as compared to future applications of nuclear power on orbit design parameters, such as eclipse time, are among the parameters included in the study. The principal aim, however, is in providing the analyst with useful parametric design information to cover the general area of earth satellite missions in the region of near-earth to cislunar space and beyond and from injection to atmospheric entry and controlled descent. The chapters are organized around the central idea of orbital operations in the 1961-1969 era with emphasis on parametric flight mechanics studies for ascent phase and parking orbits, transfer maneuvers, rendezvous maneuver, operational orbit considerations, and operational orbit control. The results are based almost entirely on the principles of flight and celestial mechanics. Numerous practical examples have been worked out in detail. This is especially important where it has been difficult or impossible to represent all possible variations of the parameters. The handbook contains analytical formulae and sufficient textual material to permit their proper use. The analytic methods consist of both exact and rapid, approximate methods. Scores of tables, working graphs and illustrations amplify the mathematical models which, together with important facts and data, cover the engineering and scientific applications of orbital mechanics. Each of the five major chapters are arranged to provide a rapid review of an entire

  11. Regularization in Orbital Mechanics; Theory and Practice

    Science.gov (United States)

    Roa, Javier

    2017-09-01

    Regularized equations of motion can improve numerical integration for the propagation of orbits, and simplify the treatment of mission design problems. This monograph discusses standard techniques and recent research in the area. While each scheme is derived analytically, its accuracy is investigated numerically. Algebraic and topological aspects of the formulations are studied, as well as their application to practical scenarios such as spacecraft relative motion and new low-thrust trajectories.

  12. Orbiting Space Debris: Dangers, Measurement and Mitigation

    Science.gov (United States)

    1992-01-01

    September 1990.. 11 "The Orbital Debris Monitor" is published by Darrin McKnight. Information is available at 12624 Veny Place, Fairfax, VA 22033...1975). These treaties cover numerous areas, including the peaceful use of space and the possible contamination of 192 Earth from space-borne diseases ...construed as applying to space debris; however, the main concern at the time of passage was the introduction of extraterrestrial diseases into the

  13. Extravehicular activity at geosynchronous earth orbit

    Science.gov (United States)

    Shields, Nicholas, Jr.; Schulze, Arthur E.; Carr, Gerald P.; Pogue, William

    1988-01-01

    The basic contract to define the system requirements to support the Advanced Extravehicular Activity (EVA) has three phases: EVA in geosynchronous Earth orbit; EVA in lunar base operations; and EVA in manned Mars surface exploration. The three key areas to be addressed in each phase are: environmental/biomedical requirements; crew and mission requirements; and hardware requirements. The structure of the technical tasks closely follows the structure of the Advanced EVA studies for the Space Station completed in 1986.

  14. Diplopia secondary to orbital fracture in adults.

    Science.gov (United States)

    Pérez-Flores, I; Santos-Armentia, E; Fernández-Sanromán, J; Costas-López, A; Fernández-Ferro, M

    2017-09-08

    To evaluate the incidence and evolution of diplopia as a complication of orbital fractures in adults. A review was conducted on medical records of all consecutive adults with orbital fracture referred between January 2014 and December 2015. An analysis was made of the incidence of diplopia secondary to fracture in the acute phase and its evolution. A descriptive study was performed on the variables related to patients, fractures, and fracture and diplopia treatment. The study included 39patients with a mean age of 48years (17-85). Of all the patients, 17 (43.6%) presented with diplopia in the acute phase. Differences were found between the groups with and without diplopia in relation to muscle entrapment diagnosed by orbital computed tomography, duction limitation, and fracture surgery ≤1week (P=.02, P=.00, P=.04, respectively). Out of the 17patients with diplopia, 12 had a mean follow-up of 18weeks (1-72), and in 10 (83.3%) diplopia was resolved in a mean time of 10weeks (1-72). There were spontaneous resolution in 4 (33.3%) patients, and resolution after fracture surgery in 4 (57%) of the 7 that underwent surgery. In 4cases (33.3%) prisms were prescribed, and 2 (16.6%) required strabismus surgery. Diplopia secondary to orbital fracture in adults is frequent, but it is resolved in most cases spontaneously or after fracture surgery. A few patients will require prisms and/or strabismus surgery. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Taurus Lightweight Manned Spacecraft Earth orbiting vehicle

    Science.gov (United States)

    Bosset, M.

    The Taurus Lightweight Manned Spacecraft (LMS) was developed by students of the University of Maryland's Aerospace Engineering course in Space Vehicle Design. That course required students to design an Alternative Manned Spacecraft (AMS) to augment or replace the Space Transportation System and meet the following design requirements: (1) launch on the Taurus Booster being developed by Orbital Sciences Corporation; (2) 99.9 percent assured crew survival rate; (3) technology cutoff date of 1 Jan. 1991; (4) compatibility with current space administration infrastructure; and (5) first flight by May 1995. The Taurus LMS design meets the above requirements and represents an initial step toward larger and more complex spacecraft. The Taurus LMS has a very limited application when compared to the space shuttle, but it demonstrates that the U.S. can have a safe, reliable, and low-cost space system. The Taurus LMS is a short mission duration spacecraft designed to place one man into low Earth orbit (LEO). The driving factor for this design was the low payload carrying capabilities of the Taurus Booster - 1300 kg to a 300-km orbit. The Taurus LMS design is divided into six major design sections. The Human Factors section deals with the problems of life support and spacecraft cooling. The Propulsion section contains the Abort System, the Orbital Maneuvering System (OMS), the Reaction Control System (RCS), and Power Generation. The thermal protection systems and spacecraft structure are contained in the Structures section. The Avionics section includes Navigation, Attitude Determination, Data Processing, Communication systems, and Sensors. The Mission Analysis section was responsible for ground processing and spacecraft astrodynamics. The Systems Integration Section pulled the above sections together into one spacecraft, and addressed costing and reliability.

  16. Recalculated orbits of 8 double stars

    Directory of Open Access Journals (Sweden)

    Olević D.

    2000-01-01

    Full Text Available The authors present new orbital elements for the following pairs: ADS 1227 ADS 3317, ADS 8128, ADS 8239, ADS 8242, ADS 8539, ADS 8949 and McA 61. Individual masses for these pairs are also calculated. For the pairs ADS 8128, ADS 8239, ADS 8539 and ADS 8949 calculated parallaxes are in accordance with the corresponding parallaxes of the Hipparchos Program.

  17. Orbital Debris: Past, Present, and Future

    Science.gov (United States)

    Stansbery, Gene; Johnson, Nicholas

    2013-01-01

    In the early days of spaceflight, the gBig Sky h theory was the near universally accepted paradigm for dealing with collisions of orbiting objects. This theory was also used during the early years of the aviation industry. Just as it did in aviation, the gBig Sky h theory breaks down as more and more objects accumulate in the environment. Fortunately, by the late 1970 fs some visionaries in NASA and the US Department of Defense (DoD) realized that trends in the orbital environment would inevitably lead to increased risks to operational spacecraft from collisions with other orbiting objects. The NASA Orbital Debris Program was established at and has been conducted at Johnson Space Center since 1979. At the start of 1979, fewer than 5000 objects were being tracked by the US Space Surveillance Network and very few attempts had been made to sample the environment for smaller sizes. Today, the number of tracked objects has quadrupled. Ground ]based and in situ measurements have statistically sampled the LEO environment over most sizes and mitigation guidelines and requirements are common among most space faring nations. NASA has been a leader, not only in defining the debris environment, but in promoting awareness of the issues in the US and internationally, and in providing leadership in developing policies to address the issue. This paper will discuss in broad terms the evolution of the NASA debris program from its beginnings to its present broad range of debris related research. The paper will discuss in some detail current research topics and will attempt to predict future research trends.

  18. Orbit Clustering Based on Transfer Cost

    Science.gov (United States)

    Gustafson, Eric D.; Arrieta-Camacho, Juan J.; Petropoulos, Anastassios E.

    2013-01-01

    We propose using cluster analysis to perform quick screening for combinatorial global optimization problems. The key missing component currently preventing cluster analysis from use in this context is the lack of a useable metric function that defines the cost to transfer between two orbits. We study several proposed metrics and clustering algorithms, including k-means and the expectation maximization algorithm. We also show that proven heuristic methods such as the Q-law can be modified to work with cluster analysis.

  19. Optical communication beyond orbital angular momentum

    OpenAIRE

    Trichili, Abderrahmen; Rosales-Guzm?n, Carmelo; Dudley, Angela; Ndagano, Bienvenu; Ben Salem, Amine; Zghal, Mourad; Forbes, Andrew

    2016-01-01

    Mode division multiplexing (MDM) is mooted as a technology to address future bandwidth issues, and has been successfully demonstrated in free space using spatial modes with orbital angular momentum (OAM). To further increase the data transmission rate, more degrees of freedom are required to form a densely packed mode space. Here we move beyond OAM and demonstrate multiplexing and demultiplexing using both the radial and azimuthal degrees of freedom. We achieve this with a holographic approac...

  20. Numerical simulation of orbiting black holes.

    Science.gov (United States)

    Brügmann, Bernd; Tichy, Wolfgang; Jansen, Nina

    2004-05-28

    We present numerical simulations of binary black hole systems which for the first time last for about one orbital period for close but still separate black holes as indicated by the absence of a common apparent horizon. An important part of the method is the construction of comoving coordinates, in which both the angular and the radial motion are minimized through a dynamically adjusted shift condition. We use fixed mesh refinement for computational efficiency.

  1. Achieving Climate Change Absolute Accuracy in Orbit

    Science.gov (United States)

    Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.; hide

    2013-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high absolute radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high absolute accuracy will be verified and traceable on orbit to Système Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for determining the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.

  2. Treatment of traumatic infra orbital nerve paresthesia

    OpenAIRE

    Lone, Parveen Akhter; Singh, R. K.; Pal, U. S.

    2012-01-01

    This study was done to find out the role of topiramate therapy in infraorbital nerve paresthesia after miniplate fixation in zygomatic complxex fractures. A total 2 cases of unilateral zygomatic complex fracture, 2-3 weeks old with infra orbital nerve paresthesia were slected. Open reduction and plating was done in frontozygomaticregion. Antiepileptic drug tab topiramate was given in therapeutic doses and dose was increased slowly until functional recovery was noticed.

  3. Treatment of traumatic infra orbital nerve paresthesia.

    Science.gov (United States)

    Lone, Parveen Akhter; Singh, R K; Pal, U S

    2012-07-01

    This study was done to find out the role of topiramate therapy in infraorbital nerve paresthesia after miniplate fixation in zygomatic complxex fractures. A total 2 cases of unilateral zygomatic complex fracture, 2-3 weeks old with infra orbital nerve paresthesia were slected. Open reduction and plating was done in frontozygomaticregion. Antiepileptic drug tab topiramate was given in therapeutic doses and dose was increased slowly until functional recovery was noticed.

  4. DRAGON - 8U Nanosatellite Orbital Deployer

    Science.gov (United States)

    Dobrowolski, Marcin; Grygorczuk, Jerzy; Kedziora, Bartosz; Tokarz, Marta; Borys, Maciej

    2014-01-01

    The Space Research Centre of the Polish Academy of Sciences (SRC PAS) together with Astronika company have developed an Orbital Deployer called DRAGON for ejection of the Polish scientific nanosatellite BRITE-PL Heweliusz (Fig. 1). The device has three unique mechanisms including an adopted and scaled lock and release mechanism from the ESA Rosetta mission MUPUS instrument. This paper discusses major design restrictions of the deployer, unique design features, and lessons learned from development through testing.

  5. Multiple Epithelioid Hemangiomas with Orbital Involvement

    Directory of Open Access Journals (Sweden)

    Branislava Miličić

    2015-01-01

    Full Text Available Epithelioid hemangioma, also known as angiolymphoid hyperplasia with eosinophilia, is a cutaneous angioproliferative lesion that follows a benign clinical course. It is most frequently localized in the skin of the head and neck region; although it may sometimes arise deeper in soft tissues, orbital involvement is rare. Here we describe a patient who developed multiple epithelioid hemangiomas, including an intraorbital lesion. The histopathological parallels with other reactive and neoplastic lesions as well as therapeutic options are discussed.

  6. Orbit Determination Using Vinti’s Solution

    Science.gov (United States)

    2016-09-15

    solution for non- circular , non-equatorial trajectories less than 60 degrees inclination are on the order of a few hundred meters with projected...determine between a known satellite trajectory and an inbound warhead. To this end, a formal effort to catalog all known orbiting objects was...non- circular , non-equatorial trajectories less than 60 degrees inclination are on the order of a few hundred meters with projected, average error

  7. Orbital angular momentum exchange in parametric down conversion

    Science.gov (United States)

    Huguenin, J. A. O.; Martinelli, M.; Caetano, D. P.; Coutinho Dos Santos, B.; Almeida, M. P.; Souto Ribeiro, P. H.; Nussenzveig, P.; Khoury, A. Z.

    2006-05-01

    Orbital angular momentum exchange, both in cavity free stimulated parametric down conversion and in an optical parametric oscillator, is studied. In both cases, the conditions for parametric amplification are discussed in terms of the orbital angular momentum exchange between the interacting fields. It is shown that in cavity free parametric down conversion, parametric amplification is conditioned to conserve orbital angular momentum. However, for parametric oscillation, cavity and anisotropy effects play a crucial role in the orbital angular momentum exchange between the interacting fields.

  8. LSST: Comprehensive NEO detection, characterization, and orbits

    Science.gov (United States)

    Ivezic, Zeljko; Jones, Lynne

    2014-11-01

    The Large Synoptic Survey Telescope (LSST) has Solar System mapping as one of its four key scientific design drivers, with emphasis on efficient Near-Earth Object (NEO) and Potentially Hazardous Asteroid (PHA) detection, orbit determination, and characterization. The baseline design satisfies strong constraints on the cadence of observations mandated by PHAs such as closely spaced pairs of observations to link different detections and short exposures to avoid trailing losses. Due to frequent repeat visits LSST will effectively provide its own follow-up to derive orbits for detected moving objects. We will describe detailed modeling of LSST operations, incorporating real historical weather and seeing data from Cerro Pachon in Chile, the LSST site, which shows that LSST using its baseline design cadence could find 90% of the PHAs with diameters larger than 250 m, and 75% of those greater than 140 m within ten years. However, simulations also show that LSST can reach the completeness of 90% of PHAs larger than 140m by optimizing observing cadence andextending the survey lifetime to 12 years. In addition to detecting and determining orbits for these PHAs, LSST will also provide valuable data on their physical characteristics through accurate color and variability measurements, which can be used to determine approximate taxonomical types, better size estimates by constraining albedos, rotation periods, and shape characteristics; thus constraining PHA properties relevant for risk mitigation strategies.

  9. Orbital Advection with Magnetohydrodynamics and Vector Potential

    Energy Technology Data Exchange (ETDEWEB)

    Lyra, Wladimir [Department of Physics and Astronomy, California State University Northrige, 18111 Nordhoff Street, Northridge CA 91130 (United States); McNally, Colin P. [Astronomy Unit, School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Heinemann, Tobias [Niels Bohr International Academy, The Niels Bohr Institute, Blegdamsvej 17, DK-2100, Copenhagen Ø (Denmark); Masset, Frédéric, E-mail: wlyra@csun.edu [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Av. Universidad s/n, 62210 Cuernavaca, Mor. (Mexico)

    2017-10-01

    Orbital advection is a significant bottleneck in disk simulations, and a particularly tricky one when used in connection with magnetohydrodynamics. We have developed an orbital advection algorithm suitable for the induction equation with magnetic potential. The electromotive force is split into advection and shear terms, and we find that we do not need an advective gauge since solving the orbital advection implicitly precludes the shear term from canceling the advection term. We prove and demonstrate the third order in time accuracy of the scheme. The algorithm is also suited to non-magnetic problems. Benchmarked results of (hydrodynamical) planet–disk interaction and of the magnetorotational instability are reproduced. We include detailed descriptions of the construction and selection of stabilizing dissipations (or high-frequency filters) needed to generate practical results. The scheme is self-consistent, accurate, and elegant in its simplicity, making it particularly efficient for straightforward finite-difference methods. As a result of the work, the algorithm is incorporated in the public version of the Pencil Code, where it can be used by the community.

  10. TRMM On Orbit Attitude Control System Performance

    Science.gov (United States)

    Robertson, Brent; Placanica, Sam; Morgenstern, Wendy

    1999-01-01

    This paper presents an overview of the Tropical Rainfall Measuring Mission (TRMM) Attitude Control System (ACS) along with detailed in-flight performance results for each operational mode. The TRMM spacecraft is an Earth-pointed, zero momentum bias satellite launched on November 27, 1997 from Tanegashima Space Center, Japan. TRMM is a joint mission between NASA and the National Space Development Agency (NASDA) of Japan designed to monitor and study tropical rainfall and the associated release of energy. Launched to provide a validation for poorly known rainfall data sets generated by global climate models, TRMM has demonstrated its utility by reducing uncertainties in global rainfall measurements by a factor of two. The ACS is comprised of Attitude Control Electronics (ACE), an Earth Sensor Assembly (ESA), Digital Sun Sensors (DSS), Inertial Reference Units (IRU), Three Axis Magnetometers (TAM), Coarse Sun Sensors (CSS), Magnetic Torquer Bars (MTB), Reaction Wheel Assemblies (RWA), Engine Valve Drivers (EVD) and thrusters. While in Mission Mode, the ESA provides roll and pitch axis attitude error measurements and the DSS provide yaw updates twice per orbit. In addition, the TAM in combination with the IRU and DSS can be used to provide pointing in a contingency attitude determination mode which does not rely on the ESA. Although the ACS performance to date has been highly successful, lessons were learned during checkout and initial on-orbit operation. This paper describes the design, on-orbit checkout, performance and lessons learned for the TRMM ACS.

  11. Orbital tuberculosis: a review of the literature.

    Science.gov (United States)

    Madge, Simon N; Prabhakaran, Venkatesh C; Shome, Debraj; Kim, Usha; Honavar, Santosh; Selva, Dinesh

    2008-01-01

    To provide an up-to-date review of the clinical presentations, investigations, and management of orbital tuberculosis (OTB). Systematic review of the literature concerning OTB, limiting the results to English-language peer-reviewed journals. Seventy-nine patients from 39 publications were identified as cases of OTB. The condition presents in one of five forms: classical periostitis; orbital soft tissue tuberculoma or cold abscess, with no bony involvement; OTB with bony involvement; spread from the paranasal sinuses; and tuberculous dacryoadenitis. The ocular adnexa, including the nasolacrimal system and overlying skin, may also be involved. Diagnosis can be difficult and may necessitate an orbital biopsy, in which acid-fast bacilli (AFB) and characteristic histopathology may be seen. Growth of Mycobacterium tuberculosis (mTB) from such a specimen remains the gold standard for diagnosis. Ancillary investigations include tuberculin skin tests and chest radiography, but more recently alternatives such as whole blood interferon-gamma immunological tests and PCR-based tests of pathological specimens have proven useful. The management of OTB is complex, requiring a stringent public health strategy and high levels of patient adherence, combined with long courses of multiple anti-tuberculous medications. The interaction of the human immunodeficiency virus (HIV) with TB may further complicate management.

  12. A Rare Tumor of the Orbit: Angiomyxoma

    Directory of Open Access Journals (Sweden)

    Adem Türk

    2014-12-01

    Full Text Available Angiomyxoma, which is a rare mesenchymal tumor, has a propensity for occurring in the trunk, head and neck, extremities, and the genital region. Development of the tumor in the orbit is extremely rare, and only a few studies have been reported to date. In this study, we present a 26-year-old female patient who was admitted with a complaint of growing mass at her left upper eyelid during the previous 9 months. Magnetic resonance imaging revealed a well-demarcated lesion appearing as hypointense on T1- and hyperintense on T2- weighted images in the left orbit; the mass was totally excised. Histopathological examination revealed a tumor comprising spindle shaped cells in myxoid stroma sprinkled with small vascular structure. The tumor tissue was positive for alcian blue and vimentin, and not for S100 on staining. Histopathological examination led to the diagnosis of orbital angiomyxoma. The case was followed-up for 18 months without any evidence of recurrence. (Turk J Ophthalmol 2014; 44: 496-8

  13. Periodic orbits and TDHF phase space structure

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Yukio; Iwasawa, Kazuo [Tsukuba Univ., Ibaraki (Japan). Inst. of Physics; Tsukuma, Hidehiko; Sakata, Fumihiko

    1998-03-01

    The collective motion of atomic nuclei is closely coupled with the motion of nucleons, therefore, it is nonlinear, and the contents of the motion change largely with the increase of its amplitude. As the framework which describes the collective motion accompanied by the change of internal structure, time-dependent Hurtley Fock (TDHF) method is suitable. At present, the authors try to make the method for studying the large region structure in quantum system by utilizing the features of the TDHF phase space. The studies made so far are briefed. In this report, the correspondence of the large region patterns appearing in the band structure chart of three-level model with the periodic orbit group in the TDHF phase space is described. The Husimi function is made, and it possesses the information on the form of respective corresponding intrinsic state. The method of making the band structure chart is explained. There are three kinds of the tendency in the intrinsic state group. The E-T charts are made for the band structure charts to quantitatively express the large region tendency. The E-T chart and the T{sub r}-T chart are drawn for a selected characteristic orbit group. It became to be known that the large region properties of the quantum intrinsic state group of three-level model can be forecast by examining the properties of the periodic orbit group in the TDHF phase space. (K.I.)

  14. Management of pediatric orbital cellulitis and abscess.

    Science.gov (United States)

    Bedwell, Joshua; Bauman, Nancy M

    2011-12-01

    Orbital cellulitis and abscess formation in pediatric patients usually arises as a complication of acute sinusitis and if untreated may cause visual loss or life-threatening intracranial complications. This review describes the current evaluation and management of this condition. Computed tomography with contrast remains the optimal imaging study for orbital inflammation. Orbital inflammation is still classified by Chandler's original description as preseptal or postseptal and nearly all cases of preseptal cellulitis are managed with oral antibiotics. Most cases of postseptal cellulitis are managed with intravenous antibiotics, although surgical therapy is required for some abscesses, particularly large ones. Patients under 9 years respond to medical management more frequently than older patients but recent studies confirm that even children over 9 with small or moderate-sized abscesses and normal vision deserve a medical trial before surgical intervention. Medial subperiosteal abscesses that fail medical therapy are usually drained endoscopically, whereas lateral or intraconal abscesses require an open procedure. Periorbital complications of sinusitis in pediatric patients often respond to medical therapy but may require surgical intervention to prevent serious complications. Continuous in-house evaluation of patients is necessary to observe for progression of symptoms and to optimize outcome.

  15. Orbital Debris-Debris Collision Avoidance

    CERN Document Server

    Mason, James; Marshall, William; Levit, Creon

    2011-01-01

    We investigate the feasibility of using a medium-powered (5kW) ground-based laser combined with a ground-based telescope to prevent collisions between debris objects in low-Earth orbit (LEO), for which there is no current, effective mitigation strategy. The scheme utilizes photon pressure alone as a means to perturb the orbit of a debris object. Applied over multiple engagements, this alters the debris orbit sufficiently to reduce the risk of an upcoming conjunction. We employ standard assumptions for atmospheric conditions and the resulting beam propagation. Using case studies designed to represent the properties (e.g. area and mass) of the current debris population, we show that one could significantly reduce the risk of more than half of all debris-debris collisions using only one such laser/telescope facility. We speculate on whether this could mitigate the debris fragmentation rate such that it falls below the natural debris re-entry rate due to atmospheric drag, and thus whether continuous long-term ope...

  16. Orbital dermoid and epidermoid cysts: Case study

    Directory of Open Access Journals (Sweden)

    Veselinović Dragan

    2010-01-01

    Full Text Available Introduction. Dermoid and epidermoid cysts of the orbit belong to choristomas, tumours that originate from the aberrant primordial tissue. Clinically, they manifest as cystic movable formations mostly localized in the upper temporal quadrant of the orbit. They are described as both superficial and deep formations with most frequently slow intermittent growth. Apart from aesthetic effects, during their growth, dermoid and epidermoid cysts can cause disturbances in the eye motility, and in rare cases, also an optical nerve compression syndrome. Case Outline. In this paper, we described a child with a congenital orbital dermoid cyst localized in the upper-nasal quadrant that was showing signs of a gradual enlargement and progression. The computerized tomography revealed a cyst of 1.5-2.0 cm in size. At the Maxillofacial Surgery Hospital in Niš, the dermoid cyst was extirpated in toto after orbitotomy performed by superciliary approach. Postoperative course was uneventful, without inflammation signs, and after two weeks excellent functional and aesthetic effects were achieved. Conclusion. Before the decision to treat the dermoid and epidermoid cysts operatively, a detailed diagnostic procedure was necessary to be done in order to locate the cyst precisely and determine its size and possible propagation into the surrounding periorbital structures. Apart from cosmetic indications, operative procedures are recommended in the case of cysts with constant progressions, which cause the pressure to the eye lobe, lead to motility disturbances and indirectly compress the optical nerve and branches of the cranial nerves III, IV and VI.

  17. Spin-orbit scattering in superconducting nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Alhassid, Y. [Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, Connecticut, 06520 (United States); Nesterov, K.N. [Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin, 53706 (United States)

    2017-06-15

    We review interaction effects in chaotic metallic nanoparticles. Their single-particle Hamiltonian is described by the proper random-matrix ensemble while the dominant interaction terms are invariants under a change of the single-particle basis. In the absence of spin-orbit scattering, the nontrivial invariants consist of a pairing interaction, which leads to superconductivity in the bulk, and a ferromagnetic exchange interaction. Spin-orbit scattering breaks spin-rotation invariance and when it is sufficiently strong, the only dominant nontrivial interaction is the pairing interaction. We discuss how the magnetic response of discrete energy levels of the nanoparticle (which can be measured in single-electron tunneling spectroscopy experiments) is affected by such pairing correlations and how it can provide a signature of pairing correlations. We also consider the spin susceptibility of the nanoparticle and discuss how spin-orbit scattering changes the signatures of pairing correlations in this observable. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. The accuracy of orbit estimation for the low-orbit satellites LARETS and WESTPAC

    Science.gov (United States)

    Rutkowska, Milena

    The LARETS satellite was launched on September 26, 2004, into a circular orbit at an altitude of 690 km and with an inclination of 98.2°. This mission is a successor to the WESTPAC satellite which was launched to an altitude of 835 km six years before. The study is based on the observations taken by the global network of laser stations during the period from December 30, 2003 to March 17, 2004 for LARETS. This study is aimed at the precise orbit computation of LARETS. The experience acquired during the orbit estimation of WESTPAC was applied to the orbit investigation of LARETS. The WESTPAC was merely used for reference and initial parameters of the force model [Rutkowska, M., Noomenn, R., Global orbit analysis of the satellite WESTPAC, Adv. Space Res., 30(2), 265-270, 2002]. The orbit of LARETS was estimated with an rms-of-fit to the SLR measurements of 3.9 cm, using the following computation model: the CSR TEG-4 gravity field up to degree and order (200,200), the Ray tide model, the MSIS86 model for atmospheric density [Hedin, A.E., MSIS-86 Thermospheric Model, J. Geophys. Res., 92 (A5), 4649-4662, 1987], and the solution of 8-hourly CD-values. It has been verified that the modeling of the gravity field up to degree and order (100,100) which gives the same rms-of-fit value. Estimated orbits for both satellites are compared to each other in Fig. 2. All computations are performed with the NASA program GEODYN II [Eddy, W.F, McCarthy, J.J., Pavlis, D.E., Marshall, J.A., Luthce, S.B., Tsaoussi, L.S., GEODYN II System Operations Manual, vol. 1-5, ST System Corp., Lanham MD, USA, 1990].

  19. Observable Priors: Limiting Biases in Estimated Parameters for Incomplete Orbits

    Science.gov (United States)

    Kosmo, Kelly; Martinez, Gregory; Hees, Aurelien; Witzel, Gunther; Ghez, Andrea M.; Do, Tuan; Sitarski, Breann; Chu, Devin; Dehghanfar, Arezu

    2017-01-01

    Over twenty years of monitoring stellar orbits at the Galactic center has provided an unprecedented opportunity to study the physics and astrophysics of the supermassive black hole (SMBH) at the center of the Milky Way Galaxy. In order to constrain the mass of and distance to the black hole, and to evaluate its gravitational influence on orbiting bodies, we use Bayesian statistics to infer black hole and stellar orbital parameters from astrometric and radial velocity measurements of stars orbiting the central SMBH. Unfortunately, most of the short period stars in the Galactic center have periods much longer than our twenty year time baseline of observations, resulting in incomplete orbital phase coverage--potentially biasing fitted parameters. Using the Bayesian statistical framework, we evaluate biases in the black hole and orbital parameters of stars with varying phase coverage, using various prior models to fit the data. We present evidence that incomplete phase coverage of an orbit causes prior assumptions to bias statistical quantities, and propose a solution to reduce these biases for orbits with low phase coverage. The explored solution assumes uniformity in the observables rather than in the inferred model parameters, as is the current standard method of orbit fitting. Of the cases tested, priors that assume uniform astrometric and radial velocity observables reduce the biases in the estimated parameters. The proposed method will not only improve orbital estimates of stars orbiting the central SMBH, but can also be extended to other orbiting bodies with low phase coverage such as visual binaries and exoplanets.

  20. Evaluation of Pediatric Patients with Orbital and Preseptal Cellulitis

    Directory of Open Access Journals (Sweden)

    Eren Cagan

    2015-06-01

    Conclusion: Preseptal cellulitis is more frequently observed than orbital cellulitis. The most important predisposing factor for orbital cellulitis is sinusitis. Patients with preseptal cellulitis suspected clinically may be diagnosed with orbital cellulitis radiologically. As a result radiological imaging of preseptal cellulitis patients should be considered. [Cukurova Med J 2015; 40(2.000: 267-274