WorldWideScience

Sample records for orbit

  1. 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.

  2. Orbital cellulitis

    Science.gov (United States)

    ... hemolytic streptococci may also cause orbital cellulitis. Orbital cellulitis infections in children may get worse very quickly and ... in the space around the eye. An orbital cellulitis infection can get worse very quickly. A person with ...

  3. Orbital pseudotumor

    Science.gov (United States)

    ... Goodlick TA, Kay MD, Glaser JS, Tse DT, Chang WJ. Orbital disease and neuro-ophthalmology. In: Tasman ... 423. Review Date 8/20/2016 Updated by: Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La ...

  4. 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...

  5. Geometric orbit datum and orbit covers

    Institute of Scientific and Technical Information of China (English)

    梁科; 侯自新

    2001-01-01

    Vogan conjectured that the parabolic induction of orbit data is independent of the choice of the parabolic subgroup. In this paper we first give the parabolic induction of orbit covers, whose relationship with geometric orbit datum is also induced. Hence we show a geometric interpretation of orbit data and finally prove the conjugation for geometric orbit datum using geometric method.

  6. Orbit analysis

    Energy Technology Data Exchange (ETDEWEB)

    Michelotti, L.

    1995-01-01

    The past fifteen years have witnessed a remarkable development of methods for analyzing single particle orbit dynamics in accelerators. Unlike their more classic counterparts, which act upon differential equations, these methods proceed by manipulating Poincare maps directly. This attribute makes them well matched for studying accelerators whose physics is most naturally modelled in terms of maps, an observation that has been championed most vigorously by Forest. In the following sections the author sketchs a little background, explains some of the physics underlying these techniques, and discusses the best computing strategy for implementing them in conjunction with modeling accelerators.

  7. Inflammation of the Orbit

    Science.gov (United States)

    ... Eye Exams, Study Finds 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 ...

  8. Imaging of Orbital Infections

    OpenAIRE

    Seyed Hassan Mostafavi

    2010-01-01

    Preseptal and orbital cellulitis occur more commonly in children than adults. The history and physical examination are crucial in distinguishing between preseptal and orbital cellulitis. The orbital septum delineates the anterior eyelid soft tissues from the orbital soft tissue. Infections anterior to the orbital septum are classified as preseptal cellulitis and those posterior to the orbital septum are termed orbital cellulitis. "nRecognition of orbital involvement is important not only...

  9. Orbital liposarcoma.

    Science.gov (United States)

    Borbolla-Pertierra, A M; Morales-Baños, D R; Martínez-Nava, L R; Garrido-Sánchez, G A; López-Hernández, C M; Velasco-Ramos, P

    2017-02-01

    The case is presented of a 46-year-old male with right eye proptosis and conjunctival hyperaemia, of 18 months onset. A well-defined intraconal mass was found in the computed tomography. In magnetic resonance this was hypo-intense on T1, enhanced with gadolinium and hyperintense on T2. Excisional biopsy was performed, which was reported as a well-differentiated liposarcoma in the histopathology study. Liposarcoma is a malignant adipose tissue tumour. It is very rare in the orbit, with 5 histological types, the most common being myxoid. The treatment of choice is wide surgical excision and may be accompanied with radiotherapy. As it is an infiltrative tumour, It has a high rate of recurrence. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Small Orbits

    CERN Document Server

    Borsten, L; Ferrara, S; Marrani, A; Rubens, W

    2012-01-01

    We study both the "large" and "small" U-duality charge orbits of extremal black holes appearing in D = 5 and D = 4 Maxwell-Einstein supergravity theories with symmetric scalar manifolds. We exploit a formalism based on cubic Jordan algebras and their associated Freudenthal triple systems, in order to derive the minimal charge representatives, their stabilizers and the associated "moduli spaces". After recalling N = 8 maximal supergravity, we consider N = 2 and N = 4 theories coupled to an arbitrary number of vector multiplets, as well as N = 2 magic, STU, ST^2 and T^3 models. While the STU model may be considered as part of the general N = 2 sequence, albeit with an additional triality symmetry, the ST^2 and T^3 models demand a separate treatment, since their representative Jordan algebras are Euclidean or only admit non-zero elements of rank 3, respectively. Finally, we also consider minimally coupled N = 2, matter coupled N = 3, and "pure" N = 5 theories.

  11. Updates in Orbital Tumors

    Institute of Scientific and Technical Information of China (English)

    Nila; F.Moeloek

    1993-01-01

    Orbital anatomy, the clinical features of orbital tumors, the recent development of the diagnosis and management of orbital tumors were described. The incidence of orbital tumors in Dr. Cipto Mangunkusumo Hospital in the past years were introduced. The principle of management of orbital tumors and their prognosis were discussed.

  12. Imaging of Orbital Infections

    Directory of Open Access Journals (Sweden)

    Seyed Hassan Mostafavi

    2010-05-01

    Full Text Available Preseptal and orbital cellulitis occur more commonly in children than adults. The history and physical examination are crucial in distinguishing between preseptal and orbital cellulitis. The orbital septum delineates the anterior eyelid soft tissues from the orbital soft tissue. Infections anterior to the orbital septum are classified as preseptal cellulitis and those posterior to the orbital septum are termed orbital cellulitis. "nRecognition of orbital involvement is important not only because of the threatened vision loss associated with orbital cellulitis but also because of the potential for central nervous system complications including cavernous sinus thrombosis, meningitis, and death. "nOrbital imaging should be obtained in all patients suspected of having orbital cellulitis. CT is preferred to MR imaging, as the orbital tissues have high con-trast and the bone can be well visualized. Orbital CT scanning allows localization of the disease process to the preseptal area, the extraconal or intraconal fat, or the subperiosteal space. Axial CT views allow evaluation of the medial orbit and ethmoid sinuses, whereas coronal scans image the orbital roof and floor and the frontal and maxillary sinuses. If direct coronal imaging is not possible, reconstruction of thin axial cuts may help the assessment of the orbital roof and floor. Potential sources of orbital cellulitis such as sinusitis, dental infection, and facial cellulitis are often detectable on CT imaging. "nIn this presentation, the imaging considerations of the orbital infections; including imaging differentiation criteria of all types of orbital infections are reviewed.

  13. Preseptal Cellulitis, Orbital Cellulitis, Orbital Abscess

    OpenAIRE

    Rana Altan Yaycıoğlu

    2012-01-01

    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 al...

  14. Bilateral orbital cavernous haemangiomas.

    OpenAIRE

    Fries, P D; Char, D. H.

    1988-01-01

    Simultaneous bilateral orbital lesions are rare. The differential diagnosis includes orbital pseudotumour, metastasis, leukaemia, lymphoma, Wegener's granulomatosis, and neurofibromatosis. We report what we believe to be the first case of bilateral orbital cavernous haemangiomas.

  15. Orbital dystopia due to orbital roof defect.

    Science.gov (United States)

    Rha, Eun Young; Joo, Hong Sil; Byeon, Jun Hee

    2013-01-01

    We performed a retrospective review of patients who presented with delayed dystopia as a consequence of an orbital roof defect due to fractures and nontraumatic causes to search for a correlation between orbital roof defect size and surgical indications for the treatment thereof. Retrospective analyses were performed in 7 patients, all of whom presented with delayed dystopia due to orbital roof defects, between January 2001 and June 2011. The causes of orbital roof defects were displaced orbital roof fractures (5 cases), tumor (1 case), and congenital sphenoid dysplasia (1 case). All 7 patients had initially been treated conservatively and later presented with significant dystopia. The sizes of the defects were calculated on computed tomographic scans. Among the 7 patients, aspiration of cerebrospinal fluid, which caused ocular symptoms, in 1 patient with minimal displaced orbital roof and reconstruction with calvarial bone, titanium micromesh, or Medpor in 6 other patients were performed. The minimal size of the orbital roof in patients who underwent orbital roof reconstruction was 1.2 cm (defect height) x 1.0 cm (defect length), 0.94 cm(2). For all patients with orbital dystopia, displacement of the globe was corrected without any complications, regardless of whether the patient was evaluated grossly or by radiology. In this retrospective study, continuous monitoring of clinical signs and active surgical management should be considered for cases in which an orbital roof defect is detected, even if no definite symptoms are noted, to prevent delayed sequelae.

  16. 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

  17. 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...

  18. 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....

  19. Polygons in billiard orbits

    CERN Document Server

    Don, Henk

    2011-01-01

    We study the geometry of billiard orbits on rectangular billiards. A truncated billiard orbit induces a partition of the rectangle into polygons. We prove that thirteen is a sharp upper bound for the number of different areas of these polygons.

  20. Traumatic transconjunctival orbital emphysema.

    OpenAIRE

    Stroh, E M; Finger, P T

    1990-01-01

    Orbital emphysema can be produced by trans-conjunctival migration of air from a high pressure airgun. In an industrial accident an 8 mm conjunctival laceration was produced in the superior fornix which acted as a portal of entry for air into the subconjunctival, subcutaneous, and retrobulbar spaces. Computed tomography revealed no evidence of orbital fracture and showed that traumatic orbital emphysema occurred without a broken orbital bone.

  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. Painless orbital myositis

    Directory of Open Access Journals (Sweden)

    Rahul T Chakor

    2012-01-01

    Full Text Available Idiopathic orbital inflammation is the third most common orbital disease, following Graves orbitopathy and lymphoproliferative diseases. We present a 11 year old girl with 15 days history of painless diplopia. There was no history of fluctuation of symptoms, drooping of eye lids or diminished vision. She had near total restricted extra-ocular movements and mild proptosis of the right eye. There was no conjunctival injection, chemosis, or bulb pain. There was no eyelid retraction or lid lag. Rest of the neurological examination was unremarkable.Erythrocyte sedimentation rate was raised with eosinophilia. Antinuclear antibodies were positive. Liver, renal and thyroid functions were normal. Antithyroid, double stranded deoxyribonucleic acid and acetylcholine receptor antibodies were negative. Repetitive nerve stimulation was negative. Magnetic resonance imaging (MRI of the orbit was typical of orbital myositis. The patient responded to oral steroids. Orbital myositis can present as painless diplopia. MRI of orbit is diagnostic in orbital myositis.

  3. 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 

  4. The Exoplanet Orbit Database

    CERN Document Server

    Wright, Jason T; Marcy, Geoffrey W; Han, Eunkyu; Feng, Ying; Johnson, John Asher; Howard, Andrew W; Valenti, Jeff A; Anderson, Jay; Piskunov, Nikolai

    2010-01-01

    We present a database of well determined orbital parameters of exoplanets. This database comprises spectroscopic orbital elements measured for 421 planets orbiting 357 stars from radial velocity and transit measurements as reported in the literature. We have also compiled fundamental transit parameters, stellar parameters, and the method used for the planets discovery. This Exoplanet Orbit Database includes all planets with robust, well measured orbital parameters reported in peer-reviewed articles. The database is available in a searchable, filterable, and sortable form on the Web at http://exoplanets.org through the Exoplanets Data Explorer Table, and the data can be plotted and explored through the Exoplanets Data Explorer Plotter. We use the Data Explorer to generate publication-ready plots giving three examples of the signatures of exoplanet migration and dynamical evolution: We illustrate the character of the apparent correlation between mass and period in exoplanet orbits, the selection different biase...

  5. Preseptal and orbital cellulitis

    OpenAIRE

    Emine Akçay; Gamze Dereli Can; Nurullah Çağıl

    2014-01-01

    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. epid...

  6. Orbital inflammation: Corticosteroids first.

    Science.gov (United States)

    Dagi Glass, Lora R; Freitag, Suzanne K

    2016-01-01

    Orbital inflammation is common, and may affect all ages and both genders. By combining a thorough history and physical examination, targeted ancillary laboratory testing and imaging, a presumptive diagnosis can often be made. Nearly all orbital inflammatory pathology can be empirically treated with corticosteroids, thus obviating the need for histopathologic diagnosis prior to initiation of therapy. In addition, corticosteroids may be effective in treating concurrent systemic disease. Unless orbital inflammation responds atypically or incompletely, patients can be spared biopsy.

  7. Geometric orbit datum and orbit covers

    Institute of Scientific and Technical Information of China (English)

    LIANG; Ke(

    2001-01-01

    [1]Vogan, D. , Dixmier algebras, sheets and representation theory (in Actes du colloque en I' honneur de Jacques Dixmier),Progress in Math. 92, Boston: Birkhauser Verlag, 1990, 333-397.[2]McGovern, W., Dixmier Algebras and Orbit Method, Operator Algebras, Unitary Representations and Invariant Theory,Boston: Birkhauser, 1990, 397-416.[3]Liang, K. , Parabolic inductions of nilpotent geometric orbit datum, Chinese Science Bulletin (in Chinese) , 1996, 41 (23):2116-2118.[4]Vogan, D., Representations of Real Reductive Lie Groups, Boston-Basel-Stuttgart: Birkhauser, 1981.[5]Lustig, G., Spaltenstein, N., Induced unipotent class, J. London Math. Soc., 1997, 19. 41-52.[6]Collingwood, D. H. , McGovern, W. M. , Nilpotent Orbits in Semisimple Lie Algebras, New York: Van Nostremt Reinhold,1993.

  8. 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.

  9. Congenital orbital encephalocele, orbital dystopia, and exophthalmos.

    Science.gov (United States)

    Hwang, Kun; Kim, Han Joon

    2012-07-01

    We present here an exceedingly rare variant of a nonmidline basal encephalocele of the spheno-orbital type, and this was accompanied with orbital dystopia in a 56-year-old man. On examination, his left eye was located more inferolaterally than his right eye, and the patient said this had been this way since his birth. The protrusion of his left eye was aggravated when he is tired. His naked visual acuity was 0.7/0.3, and the ocular pressure was 14/12 mm Hg. The exophthalmometry was 10/14 to 16 mm. His eyeball motion was not restricted, yet diplopia was present in all directions. The distance from the midline to the medial canthus was 20/15 mm. The distance from the midline to the midpupillary line was 35/22 mm. The vertical dimension of the palpebral fissure was 12/9 mm. The height difference of the upper eyelid margin was 11 mm, and the height difference of the lower eyelid margin was 8 mm. Facial computed tomography and magnetic resonance imaging showed left sphenoid wing hypoplasia and herniation of the left anterior temporal pole and dura mater into the orbit, and this resulted into left exophthalmos and encephalomalacia in the left anterior temporal pole. To the best of our knowledge, our case is the second case of basal encephalocele and orbital dystopia.

  10. Patterns of orbital disorders

    Directory of Open Access Journals (Sweden)

    Balasubramanian Thiagarajan

    2014-08-01

    Full Text Available This article discusses various patterns of presentations of orbital lesions. Since this article has been authored by an otolaryngologist, the entire concept has been viewed from otolaryngologist's angle. With the advent of nasal endoscope trans nasal access to orbit is becoming the order of the day. Major advantage being that external skin incision is avoided.

  11. LUNISOLAR INVARIANT RELATIVE ORBITS

    OpenAIRE

    Walid Ali Rahoma

    2013-01-01

    The present study deal with constructing an analytical model within Hamiltonian formulation to design invariant relative orbits due to the perturbation of J2 and the lunisolar attraction. To fade the secular drift separation over the time between two neighboring orbits, two second order conditions that guarantee that drift are derived and enforced to be equal.

  12. Reticulohistiocytoma of the Orbit

    Science.gov (United States)

    Weissman, Heather M.; Hayek, Brent R.; Grossniklaus, Hans E.

    2015-01-01

    Reticulohistiocytoma is a rare, benign histiocytic proliferation of the skin or soft tissue. While ocular involvement has been documented in the past, there have been no previously reported cases of reticulohistiocytoma of the orbit. In this report, the authors describe a reticulohistiocytoma of the orbit in a middle-aged woman. PMID:24807799

  13. Orbital Plots Using Gnuplot

    Science.gov (United States)

    Moore, Brian G.

    2000-06-01

    The plotting program Gnuplot is freely available, general purpose, easy to use, and available on a variety of platforms. Complex three-dimensional surfaces, including the familiar angular parts of the hydrogen atom orbitals, are easily represented using Gnuplot. Contour plots allow viewing the radial and angular variation of the probability density in an orbital. Examples are given of how Gnuplot is used in an undergraduate physical chemistry class to view familiar atomic orbitals in new ways or to generate views of orbital functions that the student may have not seen before. Gnuplot may also be easily integrated into the environment of a Web page; an example of this is discussed (and is available at http://onsager.bd.psu.edu/~moore/orbitals_gnuplot). The plotting commands are entered with a form and a CGI script is used to run Gnuplot and display the result back to the browser.

  14. 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.

  15. 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.

  16. Prototyping LHC Orbit Control

    CERN Document Server

    Wijnands, Thijs; Srinivasan, B

    2002-01-01

    Orbit correction consists in adjusting the strengths of the corrector magnets to make the measured beam position match a predefined reference. In the LHC, this involves around 2000 sensors and more than 1000 actuators that are distributed along both rings. The orbit correction scheme should be able to compensate for very slow orbit drifts in the range of a 10-2 Hz but also for fast motions (vibrations) up to 1 Hz. In this paper we investigate correction schemes that could be used in either case. The choice of design formalisms is based on the experience we gained with the SPS and the LEP.

  17. 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.

  18. Envelopes of Cometary Orbits

    Directory of Open Access Journals (Sweden)

    Mijajlović, Ž.

    2008-12-01

    Full Text Available We discuss cometary orbits from the standpoint of Nonstandard (Leibnitz analysis, a relatively new branch of mathematics. In particular, we consider parabolic cometary paths. It appears that, in a sense, every parabola is an ellipse.

  19. 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

  20. Antisymmetric Orbit Functions

    Directory of Open Access Journals (Sweden)

    Anatoliy Klimyk

    2007-02-01

    Full Text Available In the paper, properties of antisymmetric orbit functions are reviewed and further developed. Antisymmetric orbit functions on the Euclidean space $E_n$ are antisymmetrized exponential functions. Antisymmetrization is fulfilled by a Weyl group, corresponding to a Coxeter-Dynkin diagram. Properties of such functions are described. These functions are closely related to irreducible characters of a compact semisimple Lie group $G$ of rank $n$. Up to a sign, values of antisymmetric orbit functions are repeated on copies of the fundamental domain $F$ of the affine Weyl group (determined by the initial Weyl group in the entire Euclidean space $E_n$. Antisymmetric orbit functions are solutions of the corresponding Laplace equation in $E_n$, vanishing on the boundary of the fundamental domain $F$. Antisymmetric orbit functions determine a so-called antisymmetrized Fourier transform which is closely related to expansions of central functions in characters of irreducible representations of the group $G$. They also determine a transform on a finite set of points of $F$ (the discrete antisymmetric orbit function transform. Symmetric and antisymmetric multivariate exponential, sine and cosine discrete transforms are given.

  1. [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

  2. Orbit Propagation and Determination of Low Earth Orbit Satellites

    OpenAIRE

    Ho-Nien Shou

    2014-01-01

    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 t...

  3. Orbits for sixteen binaries

    Directory of Open Access Journals (Sweden)

    Cvetković Z.

    2006-01-01

    Full Text Available In this paper orbits for 13 binaries are recalculated and presented. The reason is that recent observations show higher residuals than the corresponding ephemerides calculated by using the orbital elements given in the Sixth Catalog of Orbits of Visual Binary Stars. The binaries studied were: WDS 00182+7257 = A 803, WDS 00335+4006 = HO 3, WDS 00583+2124 = BU 302, WDS 01011+6022 = A 926, WDS 01014+1155 = BU 867, WDS 01112+4113 = A 655, WDS 01361−2954 + HJ 3447, WDS 02333+5219 = STT 42 AB,WDS 04362+0814 = A 1840 AB,WDS 08017−0836 = A 1580, WDS 08277−0425 = A 550, WDS 17471+1742 = STF 2215 and WDS 18025+4414 = BU 1127 Aa-B. In addition, for three binaries - WDS 01532+1526 = BU 260, WDS 02563+7253 = STF 312 AB and WDS 05003+3924 = STT 92 AB - the orbital elements are calculated for the first time. In this paper the authors present not only the orbital elements, but the masses dynamical parallaxes, absolute magnitudes and ephemerides for the next five years, as well.

  4. Helioseismology with Solar Orbiter

    CERN Document Server

    Löptien, Björn; Gizon, Laurent; Schou, Jesper; Appourchaux, Thierry; Rodríguez, Julián Blanco; Cally, Paul S; Dominguez-Tagle, Carlos; Gandorfer, Achim; Hill, Frank; Hirzberger, Johann; Scherrer, Philip H; Solanki, Sami K

    2014-01-01

    The Solar Orbiter mission, to be launched in July 2017, will carry a suite of remote sensing and in-situ instruments, including the Polarimetric and Helioseismic Imager (PHI). PHI will deliver high-cadence images of the Sun in intensity and Doppler velocity suitable for carrying out novel helioseismic studies. The orbit of the Solar Orbiter spacecraft will reach a solar latitude of up to 21 deg (up to 34 deg by the end of the extended mission) and thus will enable the first local helioseismology studies of the polar regions. Here we consider an array of science objectives to be addressed by helioseismology within the baseline telemetry allocation (51 Gbit per orbit, current baseline) and within the science observing windows (baseline 3 x 10 days per orbit). A particularly important objective is the measurement of large-scale flows at high latitudes (rotation and meridional flow), which are largely unknown but play an important role in flux transport dynamos. The full range of Earth-Sun-spacecraft angles provi...

  5. Orbital Fluid Resupply Assessment

    Science.gov (United States)

    Eberhardt, Ralph N.

    1989-01-01

    Orbital fluid resupply can significantly increase the cost-effectiveness and operational flexibility of spacecraft, satellites, and orbiting platforms and observatories. Reusable tankers are currently being designed for transporting fluids to space. A number of options exist for transporting the fluids and propellant to the space-based user systems. The fluids can be transported to space either in the Shuttle cargo bay or using expendable launch vehicles (ELVs). Resupply can thus be accomplished either from the Shuttle bay, or the tanker can be removed from the Shuttle bay or launched on an ELV and attached to a carrier such as the Orbital Maneuvering Vehicle (OMV) or Orbital Transfer Vehicle (OTV) for transport to the user to be serviced. A third option involves locating the tanker at the space station or an unmanned platform as a quasi-permanent servicing facility or depot which returns to the ground for recycling once its tanks are depleted. Current modular tanker designs for monopropellants, bipropellants, and water for space station propulsion are discussed. Superfluid helium tankers are addressed, including trade-offs in tanker sizes, shapes to fit the range of ELVs currently available, and boil-off losses associated with longer-term (greater than 6-month) space-basing. It is concluded that the mixed fleet approach to on-orbit consumables resupply offers significant advantages to the overall logistics requirements.

  6. 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.

  7. Vertical orbital dystopia.

    Science.gov (United States)

    Tan, S T; Ashworth, G; Czypionka, S; Poole, M D; Briggs, M

    1996-06-01

    Many pathologic processes may lead to vertical orbital dystopia. We reviewed 47 consecutive cases seen over a 13-year period. Twenty-nine patients underwent eye leveling procedures to improve cosmesis, 2 of these by camouflage procedures and 27 by orbital translocation. Ten patients had 16 secondary operations. There was one death, serious complications occurred in 3 patients, and nuisance complications occurred in 20 others. Seven patients developed diplopia postoperatively, and in 6 patients it was troublesome. In these, it resolved fully in 2 patients, improved to be of no consequence in 2, and in the remaining 2 troublesome symptoms persisted requiring inferior oblique muscle recession in 1. Binocular vision was never restored when not present preoperatively, and in 3 patients temporary loss occurred. There was an overall modest but significant improvement in appearance after surgery. It is concluded that vertical orbital translocation is rewarding and worthwhile.

  8. Deceleration Orbit Improvements

    Energy Technology Data Exchange (ETDEWEB)

    Church, M.

    1991-04-26

    During the accelerator studies period of 12/90-1/91 much study time was dedicated to improving the E760 deceleration ramps. 4 general goals were in mind: (1) Reduce the relative orbit deviations from the nominal reference orbit as much as possible. This reduces the potential error in the orbit length calculation - which is the primary source of error in the beam energy calculation. (2) Maximize the transverse apertures. This minimizes beam loss during deceleration and during accidental beam blow-ups. (3) Measure and correct lattice parameters. Knowledge of {gamma}{sub T}, {eta}, Q{sub h}, Q{sub v}, and the dispersion in the straight sections allows for a more accurate energy calculation and reliable SYNCH calculations. (4) Minimize the coupling. This allows one to discern between horizontal and vertical tunes.

  9. [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.

  10. Optical orbital angular momentum

    Science.gov (United States)

    Barnett, Stephen M.; Babiker, Mohamed; Padgett, Miles J.

    2017-01-01

    We present a brief introduction to the orbital angular momentum of light, the subject of our theme issue and, in particular, to the developments in the 13 years following the founding paper by Allen et al. (Allen et al. 1992 Phys. Rev. A 45, 8185 (doi:10.1103/PhysRevA.45.8185)). The papers by our invited authors serve to bring the field up to date and suggest where developments may take us next. This article is part of the themed issue ‘Optical orbital angular momentum’. PMID:28069775

  11. Optical orbital angular momentum

    Science.gov (United States)

    Barnett, Stephen M.; Babiker, Mohamed; Padgett, Miles J.

    2017-02-01

    We present a brief introduction to the orbital angular momentum of light, the subject of our theme issue and, in particular, to the developments in the 13 years following the founding paper by Allen et al. (Allen et al. 1992 Phys. Rev. A 45, 8185 (doi:10.1103/PhysRevA.45.8185)). The papers by our invited authors serve to bring the field up to date and suggest where developments may take us next. This article is part of the themed issue 'Optical orbital angular momentum'.

  12. Local orbitals by minimizing powers of the orbital variance

    DEFF Research Database (Denmark)

    Jansik, Branislav; Høst, Stinne; Kristensen, Kasper;

    2011-01-01

    It is demonstrated that a set of local orthonormal Hartree–Fock (HF) molecular orbitals can be obtained for both the occupied and virtual orbital spaces by minimizing powers of the orbital variance using the trust-region algorithm. For a power exponent equal to one, the Boys localization function...... 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...

  13. Solar Orbiter Status Report

    Science.gov (United States)

    Gilbert, Holly; St. Cyr, Orville Chris; Mueller, Daniel; Zouganelis, Yannis; Velli, Marco

    2017-08-01

    With the delivery of the instruments to the spacecraft builder, the Solar Orbiter mission is in the midst of Integration & Testing phase at Airbus in Stevenage, U.K. This mission to “Explore the Sun-Heliosphere Connection” is the first medium-class mission of ESA’s Cosmic Vision 2015-2025 program and is being jointly implemented with NASA. The dedicated payload of 10 remote-sensing and in-situ instruments will orbit the Sun as close as 0.3 A.U. and will provide measurments from the photosphere into the solar wind. The three-axis stabilized spacecraft will use Venus gravity assists to increase the orbital inclination out of the ecliptic to solar latitudes as high as 34 degrees in the extended mission. The science team of Solar Orbiter has been working closely with the Solar Probe Plus scientists to coordinate observations between these two highly-complementary missions. This will be a status report on the mission development; the interested reader is referred to the recent summary by Müller et al., Solar Physics 285 (2013).

  14. Sedna Orbit Animation

    Science.gov (United States)

    2004-01-01

    This animation shows the location of the newly discovered planet-like object, dubbed 'Sedna,' in relation to the rest of the solar system. Starting at the inner solar system, which includes the orbits of Mercury, Venus, Earth, and Mars (all in yellow), the view pulls away through the asteroid belt and the orbits of the outer planets beyond (green). Pluto and the distant Kuiper Belt objects are seen next until finally Sedna comes into view. As the field widens the full orbit of Sedna can be seen along with its current location. Sedna is nearing its closest approach to the Sun; its 10,000 year orbit typically takes it to far greater distances. Moving past Sedna, what was previously thought to be the inner edge of the Oort cloud appears. The Oort cloud is a spherical distribution of cold, icy bodies lying at the limits of the Sun's gravitational pull. Sedna's presence suggests that this Oort cloud is much closer than scientists believed.

  15. 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.

  16. Sedna Orbit Animation

    Science.gov (United States)

    2004-01-01

    This animation shows the location of the newly discovered planet-like object, dubbed 'Sedna,' in relation to the rest of the solar system. Starting at the inner solar system, which includes the orbits of Mercury, Venus, Earth, and Mars (all in yellow), the view pulls away through the asteroid belt and the orbits of the outer planets beyond (green). Pluto and the distant Kuiper Belt objects are seen next until finally Sedna comes into view. As the field widens the full orbit of Sedna can be seen along with its current location. Sedna is nearing its closest approach to the Sun; its 10,000 year orbit typically takes it to far greater distances. Moving past Sedna, what was previously thought to be the inner edge of the Oort cloud appears. The Oort cloud is a spherical distribution of cold, icy bodies lying at the limits of the Sun's gravitational pull. Sedna's presence suggests that this Oort cloud is much closer than scientists believed.

  17. 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.

  18. Orbit correction algorithm for SSRF fast orbit feedback system

    Institute of Scientific and Technical Information of China (English)

    LIU Ming; YIN Chongxian; LIU Dekang

    2009-01-01

    A fast orbit feedback system is designed at SSRF to suppress beam orbit disturbance within sub-micron in the bandwidth up to 100 Hz.The SVD (Singular value decomposition) algorithm is applied to calculate the inverse response matrix in global orbit correction.The number of singular eigenvalues will influence orbit noise suppression and corrector strengths.The method to choose singular eigenvalue rejection threshold is studied in this paper,and the simulation and experiment results are also presented.

  19. Comparison of Low Earth Orbit and Geosynchronous Earth Orbits

    Science.gov (United States)

    Drummond, J. E.

    1980-01-01

    The technological, environmental, social, and political ramifications of low Earth orbits as compared to geosynchronous Earth orbits for the solar power satellite (SPS) are assessed. The capital cost of the transmitting facilities is dependent on the areas of the antenna and rectenna relative to the requirement of high efficiency power transmission. The salient features of a low orbit Earth orbits are discussed in terms of cost reduction efforts.

  20. Diplopia secondary to orbital surgery.

    Science.gov (United States)

    Silbert, David I; Matta, Noelle S; Singman, Eric L

    2012-01-01

    Diplopia may occur following any type of ocular or pericocular surgery. The surgeries most frequently associated with postoperative diplopia include: repair of orbital fracture, endoscopic sinus surgery (from inadvertent orbital penetration), and orbital decompression for thyroid-related immune orbitopathy (TRIO). Postoperative diplopia after orbital tumor resection has been reported--e.g., after excision of fibrous dysplasia and osteoma. However, a recent case series suggests diplopia after orbital tumor resection is uncommon and transient. Surgical intervention for orbital trauma carries the highest risk of postoperative diplopia and will be the focus of this review. We will also present a case report of worsening diplopia following repair of orbital floor fracture to highlight potential motility issues that can arise when implants are employed to treat orbital floor fractures.

  1. Topics in orbit equivalence

    CERN Document Server

    Kechris, Alexander S

    2004-01-01

    This volume provides a self-contained introduction to some topics in orbit equivalence theory, a branch of ergodic theory. The first two chapters focus on hyperfiniteness and amenability. Included here are proofs of Dye's theorem that probability measure-preserving, ergodic actions of the integers are orbit equivalent and of the theorem of Connes-Feldman-Weiss identifying amenability and hyperfiniteness for non-singular equivalence relations. The presentation here is often influenced by descriptive set theory, and Borel and generic analogs of various results are discussed. The final chapter is a detailed account of Gaboriau's recent results on the theory of costs for equivalence relations and groups and its applications to proving rigidity theorems for actions of free groups.

  2. Small Mercury Relativity Orbiter

    Science.gov (United States)

    Bender, Peter L.; Vincent, Mark A.

    1989-01-01

    The accuracy of solar system tests of gravitational theory could be very much improved by range and Doppler measurements to a Small Mercury Relativity Orbiter. A nearly circular orbit at roughly 2400 km altitude is assumed in order to minimize problems with orbit determination and thermal radiation from the surface. The spacecraft is spin-stabilized and has a 30 cm diameter de-spun antenna. With K-band and X-band ranging systems using a 50 MHz offset sidetone at K-band, a range accuracy of 3 cm appears to be realistically achievable. The estimated spacecraft mass is 50 kg. A consider-covariance analysis was performed to determine how well the Earth-Mercury distance as a function of time could be determined with such a Relativity Orbiter. The minimum data set is assumed to be 40 independent 8-hour arcs of tracking data at selected times during a two year period. The gravity field of Mercury up through degree and order 10 is solved for, along with the initial conditions for each arc and the Earth-Mercury distance at the center of each arc. The considered parameters include the gravity field parameters of degree 11 and 12 plus the tracking station coordinates, the tropospheric delay, and two parameters in a crude radiation pressure model. The conclusion is that the Earth-Mercury distance can be determined to 6 cm accuracy or better. From a modified worst-case analysis, this would lead to roughly 2 orders of magnitude improvement in the knowledge of the precession of perihelion, the relativistic time delay, and the possible change in the gravitational constant with time.

  3. 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

  4. Chaos Behaviour of Molecular Orbit

    Institute of Scientific and Technical Information of China (English)

    LIU Shu-Tang; SUN Fu-Yan; SHEN Shu-Lan

    2007-01-01

    Based on H(u)ckel's molecular orbit theory,the chaos and;bifurcation behaviour of a molecular orbit modelled by a nonlinear dynamic system is studied.The relationship between molecular orbit and its energy level in the nonlinear dynamic system is obtained.

  5. Orbiter OMS and RCS technology

    Science.gov (United States)

    Boudreaux, R. A.

    1982-01-01

    Orbiter Orbital Maneuver Subsystem (OMS) and Reaction Control Subsystem (RCS) tankage has proved to be highly successful in shuttle flights on-orbit propellant transfer tests were done. Tank qualification tests along with flight demonstrations were carried out future uses of storable propellants are cited.

  6. 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.

  7. Galactic Habitable Orbits

    Science.gov (United States)

    Rahimi, A.; Mao, S.; Kawata, D.

    2014-03-01

    The fossil record shows that the Earth has experienced several mass extinctions over the past 500 million years1, and it has been suggested that there is a periodicity in extinction events on timescales of tens1 and/or hundreds of millions of years. Various hypotheses have been proposed to explain the cause of the mass extinctions, including the suggestion that the Earth's ozone layer may have been destroyed by intense radiation from a nearby supernovae2- 3, exposing the Earth's surface to damaging UV radiation. Recent observations of cores taken from the ocean floor revealed atoms of a very rare isotope of iron (60Fe) believed to have arrived on Earth around 2 million years ago as fallout from a nearby supernovae4. Astronomical evidence for that past supernovae was recently found in the debris of a young cluster of massive stars5, by tracing its past orbit, putting it at the right place at the right time to explain the mild extinction event. Here we report new high-resolution (both in space and time) N-body chemodynamical simulations (carried out with our novel code GCD+6) of the evolution of a model Milky Way Galaxy, tracing the orbit of èsun-like' stars over a 500 million year period, checking the proximity to supernovae throughout the history of the orbit and comparing the times when this occurs with past mass extinctions on Earth. We additionally explain the important effects of the spiral arm pattern, radial migration of stars and Galactic chemistry on habitability.

  8. Review of orbital imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goh, P.S. [Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074 (Singapore)], E-mail: dnrgohps@nus.edu.sg; Gi, M.T. [Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074 (Singapore); Charlton, A. [Department of Pathology, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074 (Singapore); Tan, C.; Gangadhara Sundar, J.K.; Amrith, S. [Department of Ophthalmology, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074 (Singapore)

    2008-06-15

    CT and MRI are commonly used in the evaluation of patients with suspected orbital disease. Many different diseases may present within this small anatomical space. The purpose of this article is to present a diagnostic strategy based on a compartment model. Localizing pathology to sinus, bone, extraconal space, muscle cone, intraconal space, optic nerve, globe or lacrimal fossa allows significant reduction in the number of differential diagnoses as these compartments contain different tissues which disease may involve or arise from. Certain diseases may also present in multiple compartments. Common diseases which might present in one or multiple compartments will be discussed.

  9. Lunar Exploration Orbiter (LEO)

    Science.gov (United States)

    Jaumann, R.; Spohn, T.; Hiesinger, H.; Jessberger, E. K.; Neukum, G.; Oberst, J.; Helbert, J.; Christensen, U.; Keller, H. U.; Mall, U.; Böhnhardt, H.; Hartogh, P.; Glassmeier, K.-H.; Auster, H.-U.; Moreira, A.; Werner, M.; Pätzold, M.; Palme, H.; Wimmer-Schweingruber, R.; Mandea, M.; Lesur, V.; Häusler, B.; Hördt, A.; Eichentopf, K.; Hauber, E.; Hoffmann, H.; Köhler, U.; Kührt, E.; Michaelis, H.; Pauer, M.; Sohl, F.; Denk, T.; van Gasselt, S.

    2007-08-01

    The Moon is an integral part of the Earth-Moon system, it is a witness to more than 4.5 b. y. of solar system history, and it is the only planetary body except Earth for which we have samples from known locations. The Moon is our closest companion and can easily be reached from Earth at any time, even with a relatively modest financial budget. Consequently, the Moon was the first logical step in the exploration of our solar system before we pursued more distant targets such as Mars and beyond. The vast amount of knowledge gained from the Apollo and other lunar missions of the late 1960's and early 1970's demonstrates how valuable the Moon is for the understanding of our planetary system. Even today, the Moon remains an extremely interesting target scientifically and technologically, as ever since, new data have helped to address some of our questions about the Earth-Moon system, many questions remained. Therefore, returning to the Moon is the critical stepping-stone to further exploring our immediate planetary neighborhood. In this concept study, we present scientific and technological arguments for a national German lunar mission, the Lunar Explorations Orbiter (LEO). Numerous space-faring nations have realized and identified the unique opportunities related to lunar exploration and have planned missions to the Moon within the next few years. Among these missions, LEO will be unique, because it will globally explore the Moon in unprecedented spatial and spectral resolution. LEO will significantly improve our understanding of the lunar surface composition, surface ages, mineralogy, physical properties, interior, thermal history, gravity field, regolith structure, and magnetic field. The Lunar Explorations Orbiter will carry an entire suite of innovative, complementary technologies, including high-resolution camera systems, several spectrometers that cover previously unexplored parts of the electromagnetic spectrum over a broad range of wavelengths, microwave and

  10. Periodic orbits for three and four co-orbital bodies

    Science.gov (United States)

    Verrier, P. E.; McInnes, C. R.

    2014-08-01

    We investigate the natural families of periodic orbits associated with the equilibrium configurations of the planar-restricted 1 + n-body problem for the case 2 ≤ n ≤ 4 equal-mass satellites. Such periodic orbits can be used to model both trojan exoplanetary systems and parking orbits for captured asteroids within the Solar system. For n = 2, there are two families of periodic orbits associated with the equilibria of the system: the well-known horseshoe and tadpole orbits. For n = 3, there are three families that emanate from the equilibrium configurations of the satellites, while for n = 4, there are six such families as well as numerous additional connecting families. The families of periodic orbits are all of the horseshoe or tadpole type, and several have regions of neutral linear stability.

  11. Periodic orbits for 3 and 4 co-orbital bodies

    CERN Document Server

    Verrier, Patricia

    2014-01-01

    We investigate the natural families of periodic orbits associated with the equilibrium configurations of the the planar restricted $1+n$ body problem for the case $2\\leq n \\leq 4$ equal mass satellites. Such periodic orbits can be used to model both trojan exoplanetary systems and parking orbits for captured asteroids within the solar system. For $n=2$ there are two families of periodic orbits associated with the equilibria of the system: the well known horseshoe and tadpole orbits. For $n=3$ there are three families that emanate from the equilibrium configurations of the satellites, while for $n=4$ there are six such families as well as numerous additional connecting families. The families of periodic orbits are all of the horseshoe or tadpole type, and several have regions of neutral linear stability.

  12. Orbital debris issues

    Science.gov (United States)

    Kessler, D. J.

    Orbital debris issues fall into three major topics: Environment Definition, Spacecraft Hazard, and Space Object Management. The major issue under Environment Definition is defining the debris flux for sizes smaller (10 cm in diameter) than those tracked by the North American Aerospace Defense Command (NORAD). Sources for this size debris are fragmentation of larger objects, either by explosion or collision, and solid rocket motor products. Modeling of these sources can predict fluxes in low Earth orbit which are greater than the meteoroid environment. Techniques to measure the environment in the size interval between 1 mm and 10 cm are being developed, including the use of telescopes and radar both on the ground and in space. Some impact sensors designed to detect meteoroids may have detected solid rocket motor products. Once the environment is defined, it can be combined with hypervelocity impact data and damage criteria to evaluate the Spacecraft Hazard. Shielding may be required to obtain an acceptable damage level. Space Object Management includes techniques to control the environment and the desired policy to effectively minimize the hazard to spacecraft. One control technique - reducing the likelihood of future explosions in space - has already been implemented by NASA. The effectiveness of other techniques has yet to be evaluated.

  13. [Endoscopic approaches to the orbit].

    Science.gov (United States)

    Cebula, H; Lahlou, A; De Battista, J C; Debry, C; Froelich, S

    2010-01-01

    During the last decade, the use of endoscopic endonasal approaches to the pituitary has increased considerably. The endoscopic endonasal and transantral approaches offer a minimally invasive alternative to the classic transcranial or transconjunctival approaches to the medial aspect of the orbit. The medial wall of the orbit, the orbital apex, and the optic canal can be exposed through a middle meatal antrostomy, an anterior and posterior ethmoidectomy, and a sphenoidotomy. The inferomedial wall of the orbit can be also perfectly visualized through a sublabial antrostomy or an inferior meatal antrostomy. Several reports have described the use of an endoscopic approach for the resection or the biopsy of lesions located on the medial extraconal aspect of the orbit and orbital apex. However, the resection of intraconal lesions is still limited by inadequate instrumentation. Other indications for the endoscopic approach to the orbit are the decompression of the orbit for Graves' ophthalmopathy and traumatic optic neuropathy. However, the optimal management of traumatic optic neuropathy remains very controversial. Endoscopic endonasal decompression of the optic nerve in case of tumor compression could be a more valid indication in combination with radiation therapy. Finally, the endoscopic transantral treatment of blowout fracture of the floor of the orbit is an interesting option that avoids the eyelid or conjunctive incision of traditional approaches. The collaboration between the neurosurgeon and the ENT surgeon is mandatory and reduces the morbidity of the approach. Progress in instrumentation and optical devices will certainly make this approach promising for intraconal tumor of the orbit.

  14. 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

  15. Lunar Reconnaissance Orbiter

    Science.gov (United States)

    Morgan, T.; Chin, G.

    2007-08-01

    NASA's Lunar Reconnaissance Orbiter (LRO) plans to launch in October 2008 with a companion secondary impactor mission, LCROSS, as the inaugural missions for the Exploration System Mission Directorate. LRO is a pathfinder whose objective is to obtain the needed information to prepare for eventual human return to the Moon. LRO will undertake at least one baseline year of operation with additional extended mission phase sponsored by NASA's Science Mission Directorate. LRO will employ six individual instruments to produce accurate maps and high-resolution images of future landing sites, to assess potential lunar resources, and to characterize the radiation environment. LRO will also test the feasibility of one advanced technology demonstration package. The LRO payload includes: Lunar Orbiter Laser Altimeter (LOLA) which will determine the global topography of the lunar surface at high resolution, measure landing site slopes, surface roughness, and search for possible polar surface ice in shadowed regions; Lunar Reconnaissance Orbiter Camera (LROC) which will acquire targeted narrow angle images of the lunar surface capable of resolving meter-scale features to support landing site selection, as well as wide-angle images to characterize polar illumination conditions and to identify potential resources; Lunar Exploration Neutron Detector (LEND) which will map the flux of neutrons from the lunar surface to search for evidence of water ice, and will provide space radiation environment measurements that may be useful for future human exploration; Diviner Lunar Radiometer Experiment (DLRE) which will chart the temperature of the entire lunar surface at approximately 300 meter horizontal resolution to identify cold-traps and potential ice deposits; Lyman-Alpha Mapping Project (LAMP) which will map the entire lunar surface in the far ultraviolet. LAMP will search for surface ice and frost in the polar regions and provide images of permanently shadowed regions illuminated only

  16. Orbital State Uncertainty Realism

    Science.gov (United States)

    Horwood, J.; Poore, A. B.

    2012-09-01

    Fundamental to the success of the space situational awareness (SSA) mission is the rigorous inclusion of uncertainty in the space surveillance network. The *proper characterization of uncertainty* in the orbital state of a space object is a common requirement to many SSA functions including tracking and data association, resolution of uncorrelated tracks (UCTs), conjunction analysis and probability of collision, sensor resource management, and anomaly detection. While tracking environments, such as air and missile defense, make extensive use of Gaussian and local linearity assumptions within algorithms for uncertainty management, space surveillance is inherently different due to long time gaps between updates, high misdetection rates, nonlinear and non-conservative dynamics, and non-Gaussian phenomena. The latter implies that "covariance realism" is not always sufficient. SSA also requires "uncertainty realism"; the proper characterization of both the state and covariance and all non-zero higher-order cumulants. In other words, a proper characterization of a space object's full state *probability density function (PDF)* is required. In order to provide a more statistically rigorous treatment of uncertainty in the space surveillance tracking environment and to better support the aforementioned SSA functions, a new class of multivariate PDFs are formulated which more accurately characterize the uncertainty of a space object's state or orbit. The new distribution contains a parameter set controlling the higher-order cumulants which gives the level sets a distinctive "banana" or "boomerang" shape and degenerates to a Gaussian in a suitable limit. Using the new class of PDFs within the general Bayesian nonlinear filter, the resulting filter prediction step (i.e., uncertainty propagation) is shown to have the *same computational cost as the traditional unscented Kalman filter* with the former able to maintain a proper characterization of the uncertainty for up to *ten

  17. Precise Orbit Determination for ALOS

    Science.gov (United States)

    Nakamura, Ryo; Nakamura, Shinichi; Kudo, Nobuo; Katagiri, Seiji

    2007-01-01

    The Advanced Land Observing Satellite (ALOS) has been developed to contribute to the fields of mapping, precise regional land coverage observation, disaster monitoring, and resource surveying. Because the mounted sensors need high geometrical accuracy, precise orbit determination for ALOS is essential for satisfying the mission objectives. So ALOS mounts a GPS receiver and a Laser Reflector (LR) for Satellite Laser Ranging (SLR). This paper deals with the precise orbit determination experiments for ALOS using Global and High Accuracy Trajectory determination System (GUTS) and the evaluation of the orbit determination accuracy by SLR data. The results show that, even though the GPS receiver loses lock of GPS signals more frequently than expected, GPS-based orbit is consistent with SLR-based orbit. And considering the 1 sigma error, orbit determination accuracy of a few decimeters (peak-to-peak) was achieved.

  18. 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.

  19. Exploratory orbit analysis

    Energy Technology Data Exchange (ETDEWEB)

    Michelotti, L.

    1989-03-01

    Unlike the other documents in these proceedings, this paper is neither a scientific nor a technical report. It is, rather, a short personal essay which attempts to describe an Exploratory Orbit Analysis (EOA) environment. Analyzing the behavior of a four or six dimensional nonlinear dynamical system is at least as difficult as analyzing events in high-energy collisions; the consequences of doing it badly, or slowly, would be at least as devastating; and yet the level of effort and expenditure invested in the latter, the very attention paid to it by physicists at large, must be two orders of magnitude greater than that given to the former. It is difficult to choose the model which best explains the behavior of a physical device if one does not first understand the behavior of the available models. The time is ripe for the development of a functioning EOA environment, which I will try to describe in this paper to help us achieve this goal.

  20. Orbital angular momentum microlaser

    Science.gov (United States)

    Miao, Pei; Zhang, Zhifeng; Sun, Jingbo; Walasik, Wiktor; Longhi, Stefano; Litchinitser, Natalia M.; Feng, Liang

    2016-07-01

    Structured light provides an additional degree of freedom for modern optics and practical applications. The effective generation of orbital angular momentum (OAM) lasing, especially at a micro- and nanoscale, could address the growing demand for information capacity. By exploiting the emerging non-Hermitian photonics design at an exceptional point, we demonstrate a microring laser producing a single-mode OAM vortex lasing with the ability to precisely define the topological charge of the OAM mode. The polarization associated with OAM lasing can be further manipulated on demand, creating a radially polarized vortex emission. Our OAM microlaser could find applications in the next generation of integrated optoelectronic devices for optical communications in both quantum and classical regimes.

  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. Geology orbiter comparison study

    Science.gov (United States)

    Cutts, J. A. J.; Blasius, K. R.; Davis, D. R.; Pang, K. D.; Shreve, D. C.

    1977-01-01

    Instrument requirements of planetary geology orbiters were examined with the objective of determining the feasibility of applying standard instrument designs to a host of terrestrial targets. Within the basic discipline area of geochemistry, gamma-ray, X-ray fluorescence, and atomic spectroscopy remote sensing techniques were considered. Within the discipline area of geophysics, the complementary techniques of gravimetry and radar were studied. Experiments using these techniques were analyzed for comparison at the Moon, Mercury, Mars and the Galilean satellites. On the basis of these comparative assessments, the adaptability of each sensing technique was judged as a basic technique for many targets, as a single instrument applied to many targets, as a single instrument used in different mission modes, and as an instrument capability for nongeoscience objectives.

  3. Orbit Determination Toolbox

    Science.gov (United States)

    Carpenter, James R.; Berry, Kevin; Gregpru. Late; Speckman, Keith; Hur-Diaz, Sun; Surka, Derek; Gaylor, Dave

    2010-01-01

    The Orbit Determination Toolbox is an orbit determination (OD) analysis tool based on MATLAB and Java that provides a flexible way to do early mission analysis. The toolbox is primarily intended for advanced mission analysis such as might be performed in concept exploration, proposal, early design phase, or rapid design center environments. The emphasis is on flexibility, but it has enough fidelity to produce credible results. Insight into all flight dynamics source code is provided. MATLAB is the primary user interface and is used for piecing together measurement and dynamic models. The Java Astrodynamics Toolbox is used as an engine for things that might be slow or inefficient in MATLAB, such as high-fidelity trajectory propagation, lunar and planetary ephemeris look-ups, precession, nutation, polar motion calculations, ephemeris file parsing, and the like. The primary analysis functions are sequential filter/smoother and batch least-squares commands that incorporate Monte-Carlo data simulation, linear covariance analysis, measurement processing, and plotting capabilities at the generic level. These functions have a user interface that is based on that of the MATLAB ODE suite. To perform a specific analysis, users write MATLAB functions that implement truth and design system models. The user provides his or her models as inputs to the filter commands. The software provides a capability to publish and subscribe to a software bus that is compliant with the NASA Goddard Mission Services Evolution Center (GMSEC) standards, to exchange data with other flight dynamics tools to simplify the flight dynamics design cycle. Using the publish and subscribe approach allows for analysts in a rapid design center environment to seamlessly incorporate changes in spacecraft and mission design into navigation analysis and vice versa.

  4. 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

  5. Homogeneous orbit closures and applications

    CERN Document Server

    Lindenstrauss, Elon

    2011-01-01

    We give new classes of examples of orbits of the diagonal group in the space of unit volume lattices in R^d for d > 2 with nice (homogeneous) orbit closures, as well as examples of orbits with explicitly computable but irregular orbit closures. We give Diophantine applications to the former, for instance we show that if x is the cubic root of 2 then for any y,z in R liminf |n|=0 (as |n| goes to infinity), where denotes the distance of a real number c to the integers.

  6. Orbit Alignment in Triple Stars

    Science.gov (United States)

    Tokovinin, Andrei

    2017-08-01

    The statistics of the angle Φ between orbital angular momenta in hierarchical triple systems with known inner visual or astrometric orbits are studied. A correlation between apparent revolution directions proves the partial orbit alignment known from earlier works. The alignment is strong in triples with outer projected separation less than ∼50 au, where the average Φ is about 20^\\circ . In contrast, outer orbits wider than 1000 au are not aligned with the inner orbits. It is established that the orbit alignment decreases with the increasing mass of the primary component. The average eccentricity of inner orbits in well-aligned triples is smaller than in randomly aligned ones. These findings highlight the role of dissipative interactions with gas in defining the orbital architecture of low-mass triple systems. On the other hand, chaotic dynamics apparently played a role in shaping more massive hierarchies. The analysis of projected configurations and triples with known inner and outer orbits indicates that the distribution of Φ is likely bimodal, where 80% of triples have {{Φ }}< 70^\\circ and the remaining ones are randomly aligned.

  7. New orbit correction method uniting global and local orbit corrections

    Science.gov (United States)

    Nakamura, N.; Takaki, H.; Sakai, H.; Satoh, M.; Harada, K.; Kamiya, Y.

    2006-01-01

    A new orbit correction method, called the eigenvector method with constraints (EVC), is proposed and formulated to unite global and local orbit corrections for ring accelerators, especially synchrotron radiation(SR) sources. The EVC can exactly correct the beam positions at arbitrarily selected ring positions such as light source points, simultaneously reducing closed orbit distortion (COD) around the whole ring. Computer simulations clearly demonstrate these features of the EVC for both cases of the Super-SOR light source and the Advanced Light Source (ALS) that have typical structures of high-brilliance SR sources. In addition, the effects of errors in beam position monitor (BPM) reading and steering magnet setting on the orbit correction are analytically expressed and also compared with the computer simulations. Simulation results show that the EVC is very effective and useful for orbit correction and beam position stabilization in SR sources.

  8. PyORBIT: A Python Shell For ORBIT

    Energy Technology Data Exchange (ETDEWEB)

    Jean-Francois Ostiguy; Jeffrey Holmes

    2003-07-01

    ORBIT is code developed at SNS to simulate beam dynamics in accumulation rings and synchrotrons. The code is structured as a collection of external C++ modules for SuperCode, a high level interpreter shell developed at LLNL in the early 1990s. SuperCode is no longer actively supported and there has for some time been interest in replacing it by a modern scripting language, while preserving the feel of the original ORBIT program. In this paper, we describe a new version of ORBIT where the role of SuperCode is assumed by Python, a free, well-documented and widely supported object-oriented scripting language. We also compare PyORBIT to ORBIT from the standpoint of features, performance and future expandability.

  9. 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.

  10. Diplopia and orbital wall fractures

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and su

  11. [Enophthalmos in an orbital tumor].

    Science.gov (United States)

    Szabo, Bianca; Szabo, I; Nicula, Cristina; Popescu, Livia Adriana

    2013-01-01

    Enophtalmus is an unusual sign of the orbital tumors often represented by proptosis. One patient with enophtalmus and intraorbital tumor and aplasy is presented. The treatment of choice of orbital tumor is complete surgical excision and careful follow-up. Considering the more aggressive course followed by recurrent tumor, correct diagnosis and management is essential.

  12. 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.

  13. GridOrbit public display

    DEFF Research Database (Denmark)

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

    2010-01-01

    We introduce GridOrbit, a public awareness display that visualizes the activity of a community grid used in a biology laboratory. This community grid executes bioin-formatics algorithms and relies on users to donate CPU cycles to the grid. The goal of GridOrbit is to create a shared awareness about...

  14. Diplopia and orbital wall fractures

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and

  15. Low Earth Orbiter: Terminal

    Science.gov (United States)

    Kremer, Steven E.; Bundick, Steven N.

    1999-01-01

    In response to the current government budgetary environment that requires the National Aeronautics and Space Administration (NASA) to do more with less, NASA/Goddard Space Flight Center's Wallops Flight Facility has developed and implemented a class of ground stations known as a Low Earth Orbiter-Terminal (LEO-T). This development thus provides a low-cost autonomous ground tracking service for NASA's customers. More importantly, this accomplishment provides a commercial source to spacecraft customers around the world to purchase directly from the company awarded the NASA contract to build these systems. A few years ago, NASA was driven to provide more ground station capacity for spacecraft telemetry, tracking, and command (TT&C) services with a decreasing budget. NASA also made a decision to develop many smaller, cheaper satellites rather than a few large spacecraft as done in the past. In addition, university class missions were being driven to provide their own TT&C services due to the increasing load on the NASA ground-tracking network. NASA's solution for this ever increasing load was to use the existing large aperture systems to support those missions requiring that level of performance and to support the remainder of the missions with the autonomous LEO-T systems. The LEO-T antenna system is a smaller, cheaper, and fully autonomous unstaffed system that can operate without the existing NASA support infrastructure. The LEO-T provides a low-cost, reliable space communications service to the expanding number of low-earth orbiting missions around the world. The system is also fostering developments that improve cost-effectiveness of autonomous-class capabilities for NASA and commercial space use. NASA has installed three LEO-T systems. One station is at the University of Puerto Rico, the second system is installed at the Poker Flat Research Range near Fairbanks, Alaska, and the third system is installed at NASA's Wallops Flight Facility in Virginia. This paper

  16. Video Orbits of the Geminids

    Science.gov (United States)

    Hajdukova, M.

    2014-07-01

    Geminid meteoroids, observed by the video technique, were analysed with the aim of determining the actual dispersion of their reciprocal semimajor axes 1/a within the stream. Orbits were selected from the European Video Meteor Network Database, EDMOND, (Kornos et al., 2013), from the SonotaCo Shower Catalogue (SonotaCo, 2009), and from the Czech Catalogue of Video Meteor Orbits (Koten et al., 2003). The observed orbital dispersion, including the measurement errors, was compared with that obtained from the precisely-reduced photographic orbits of Geminids from the IAU Meteor Data Center (Lindblad et al., 2003). In this paper, we concentrate on the influence of errors on the orbital dispersion. The size and distribution of observational errors determined from the long-period meteoroid streams (Hajdukova 2013), were applied to determine the real dispersion within this short-period meteoroid stream. The observed dispersions, described by the median absolute deviation in terms of 1/a, range from 0.041 to 0.050 1/au. The deviation of the median reciprocal semimajor axis from the parent (3200) Phaethon, obtained from Japanese video orbits, is 0.009 1/au, and that from the EDMOND data 0.01 1/au. This deviation obtained from the photographic orbits of the IAU Meteor Data Center was significantly greater (Hajdukova 2009). Similar results were obtained from the Czech Video Orbits Catalogue, where the value is 0.05 1/au. The investigation showed that semimajor axes of meteor orbits in both the SonotaCo and EDMOND datasets are systematically biased as a consequence of the method used for the video orbit determination, probably because corrections for atmospheric deceleration were either incorrectly made or were not done at all. Thus, the determined heliocentric velocities are underestimated, and the semimajor axes medians shifted towards smaller values. The observed distributions in 1/a from these video data become biased towards higher values of 1/a. The orbits of the Geminid

  17. 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.

  18. The 2009 Mars Telecommunications Orbiter

    Science.gov (United States)

    Wilson, G. R.; Depaula, R.; Diehl, R. E.; Edwards, C. D.; Fitzgerald, R. J.; Franklin, S. F.; Gibbs, R. G.; Kerridge, S. A.; Komarek, T. A.; Noreen, G. K.

    The first spacecraft with a primary function of providing communication links while orbiting a foreign planet has begun development for a launch in 2009. NASA's Mars Telecommunications Orbiter would use three radio bands to magnify the benefits of other future Mars missions and enable some types of missions otherwise impractical. It would serve as the Mars hub for a growing interplanetary Internet. And it would pioneer the use of planet-to-planet laser communications to demonstrate the possibility for even great networking capabilities in the future. During its nearly 10-year mission in orbit, Mars Telecommunications Orbiter would aid navigation of arriving spacecraft to their martian landing sites and monitor critical events during landings and orbit insertions. In addition, it would enable data-transmission volumes great enough to bring a virtual Mars presence to the public through a range of Internet and video features.

  19. Halo orbit to science orbit captures at planetary moons

    Science.gov (United States)

    Bokelmann, Kevin A.; Russell, Ryan P.

    2017-05-01

    Ballisticly connecting halo orbits to science orbits in the circular-restricted three-body problem is investigated. Two classes of terminal science orbits are considered: low-altitude, tight orbits that are deep in the gravity well of the secondary body, and high-altitude, loose orbits that are strongly perturbed by the gravity of the primary body. General analytic expressions are developed to provide a minimum bound on impulse cost in both the circular restricted and the Hill's approximations. The equations are applied to a broad range of planetary moons, providing a mission design reference. Systematic grid search methods are developed to numerically find feasible transfers from halo orbits at Europa, confirming the analytical lower bound formulas. The two-impulse capture options in the case of Europa reveal a diverse set of potential solutions. Tight captures result in maneuver costs of 425-550 m/s while loose captures are found with costs as low as 30 m/s. The terminal orbits are verified to avoid escape or impact for at least 45 days.

  20. VSOP-2 Orbit Determination

    Science.gov (United States)

    Takeuchi, H.; VSOP-2 Orbit Determination Sub-Working Group

    2009-08-01

    Precise orbit determination (POD) is a key factor to enable phase referencing observations with Astro-G. A POD accuracy of 30 cm is required for efficient X-band phase referencing observations, accuracy of 6 cm for K-band observations, and accuracy of 3 cm for Q-band observations. For the POD, Astro-G will be equipped with a GPS/Galileo receiver and a SLR (Satellite Laser Ranging) retroreflector array. Four POD antennas will be equipped on four sides of the satellite body, to cover all directions. The SLR will be used as a complement to the GPS at middle-to-high altitude. Because the refroreflector array should always face to the Earth direction, it will be set up on the Ka-link antenna gimbal. The most significant perturbing force for the Astro-G is solar radiation pressure (SRP). The reflectivity of each surface component should be preliminary measured in detail to model the SRP. The estimated achievable POD accuracy at apogee is 10 ˜ 30 cm in nominal case. Phase referencing observations in K- or Q-band can be performed if the enough amount of SLR tracking data can be obtained at high altitudes.

  1. Hydrogenoid orbitals revisited: From Slater orbitals to Coulomb Sturmians

    Indian Academy of Sciences (India)

    Danilo Calderini; Simonetta Cavalli; Cecilia Coletti; Gaia Grossi; Vincenzo Qquilanti

    2012-01-01

    The simple connection between the Slater orbitals, venerable in quantum chemistry, and the Coulomb Sturmian orbitals, more recently employed in atomic and molecular physics, is pointed out explicitly in view of the renewed interest in both as basis sets in applied quantum mechanics. Research in Slater orbitals mainly concerns multicentre, many-body integrals, whereas that on Sturmians exploits their orthonormality and completeness with no need of continuum states. An account of recent progress is outlined, also with reference to relationships between the two basis sets, and with the momentum space and hyperspherical harmonics representations.

  2. 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...

  3. 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.

  4. [Orbital tumor emergencies in childhood].

    Science.gov (United States)

    Morax, S; Desjardins, L

    2009-05-01

    Emergencies in childhood orbital tumorals are rare. The absolute emergency involves malignant primary orbital tumors, such as rhabdomyosarcoma or secondary malignant tumors (metastatic neuroblastoma, leukemia), involving a vital prognosis requiring prompt diagnosis. Delayed emergencies are usually vascular lesions. Among these lesions, immature orbital hemangioma, with a good prognosis, must be distinguished from orbital adnexal lymphangiomas, which are less frequent but can lead to dramatic cosmetic and functional disorders. In rare cases, they can be responsible for sudden, painful proptosis, due to orbital hemorrhage, with a risk of optic nerve compression, requiring emergency surgical treatment. Neurogenous lesions, either isolated, such as in gliomas, or associated with a systemic disease, such as Recklinghausen neurofibromatosis, threaten the functional prognosis. Diagnosis of pediatric orbital tumors is based on a good clinical examination, precise imaging investigations, and evaluation of the locoregional extension of the tumor. Biopsy is required in emergency situations, when rhabdomyosarcoma is suspected, in order to start the chemotherapy. However, the biopsy can be superfluous, and even useless or dangerous, when clinical and imaging investigations are sufficient to provide a diagnosis of capillary hemangioma, lymphangioma, or metastatic tumor from an abdominal malignancy. Treatment is closely related to the etiopathogenesis of the tumor. The outcomes are vital, functional and cosmetic. They may require orbital surgery (biopsy, tumoral resection, orbital decompression in case of a compressive hemorrhage), systemic corticotherapy (as in immature adnexal hemangioma), radiation, and chemotherapy (rhabdomyosarcoma, secondary malignant tumor). These diseases require a pediatric ophthalmological medical center specializing in orbital surgery, with close collaboration of multiple specialists such as onco-pediatricians and neurosurgeons.

  5. Ocular complications of orbital venography.

    Science.gov (United States)

    Safer, J N; Guibor, P

    1975-03-01

    Three ocular complications directly related to orbital venography are described, one resulting in permanent loss of vision,. The patient had lymphangioma of the orbit which evidently had bled secondary to increased venous pressure and injection of contrast bolus. Both of the 2 patients with transient visual disturbances had diabetic retinopathy. The common factor is felt to be an imparied vascular bed which cannot meet the stress of increased venous pressure and contrast medium injection. Conditions which predispose to ocular-orbital stasis and/or hemorrhage are discussed.

  6. CODIMENSION 3 BIFURCATIONS OF HOMOCLINIC ORBITS WITH ORBIT FLIPS AND INCLINATION FLIPS

    Institute of Scientific and Technical Information of China (English)

    SHUI SHULIANG; ZHU DEMING

    2004-01-01

    The homoclinic bifurcations in four dimensional vector fields are investigated by setting up a local coordinates near the homoclinic orbit. This homoclinic orbit is nonprincipal in the meanings that its positive semi-orbit takes orbit flip and its unstable foliation takes inclination flip. The existence, nonexistence, uniqueness and coexistence of the 1-homoclinic orbit and the 1-periodic orbit are studied. The existence of the twofold periodic orbit and three-fold periodic orbit are also obtained.

  7. Real and Hybrid Atomic Orbitals.

    Science.gov (United States)

    Cook, D. B.; Fowler, P. W.

    1981-01-01

    Demonstrates that the Schrodinger equation for the hydrogenlike atom separates in both spheroconal and prolate spheroidal coordinates and that these separations provide a sound theoretical basis for the real and hybrid atomic orbitals. (Author/SK)

  8. [Orbital metastasis in malignant melanoma].

    Science.gov (United States)

    Pedroli, G L; Hamedani, M; Barraco, P; Oubaaz, A; Morax, S

    2001-03-01

    We report the case of a 60-year-old man presenting bilateral progressive proptosis with diplopia, weight loss, tachycardia, nervosity, and stomach pain. These signs seemed at first to favor a diagnosis of Graves'ophthalmopathy. Thyroid tests were negative and the initial orbital CT scan was considered normal. A new radiological investigation 4 months later in our hospital revealed typical hypertrophy of the extraocular muscles compatible with orbital metastasis. The systemic investigations demonstrated a pulmonary tumor, multiple hepatic lesions, and several pigmented nodules of gastric mucosa. The pathology of pulmonary and gastric specimens confirmed the diagnosis of malignant melanoma. The primary lesion remains unknown. The authors discuss the differential diagnoses of orbital metastasis and the radiological characteristics of orbital metastasis in malignant melanoma.

  9. NASA Orbital Debris Baseline Populations

    Science.gov (United States)

    Krisko, Paula H.; Vavrin, A. B.

    2013-01-01

    The NASA Orbital Debris Program Office has created high fidelity populations of the debris environment. The populations include objects of 1 cm and larger in Low Earth Orbit through Geosynchronous Transfer Orbit. They were designed for the purpose of assisting debris researchers and sensor developers in planning and testing. This environment is derived directly from the newest ORDEM model populations which include a background derived from LEGEND, as well as specific events such as the Chinese ASAT test, the Iridium 33/Cosmos 2251 accidental collision, the RORSAT sodium-potassium droplet releases, and other miscellaneous events. It is the most realistic ODPO debris population to date. In this paper we present the populations in chart form. We describe derivations of the background population and the specific populations added on. We validate our 1 cm and larger Low Earth Orbit population against SSN, Haystack, and HAX radar measurements.

  10. Quark spin-orbit correlations

    CERN Document Server

    Lorcé, Cédric

    2014-01-01

    The proton spin puzzle issue focused the attention on the parton spin and orbital angular momentum contributions to the proton spin. However, a complete characterization of the proton spin structure requires also the knowledge of the parton spin-orbit correlation. We showed that this quantity can be expressed in terms of moments of measurable parton distributions. Using the available phenomenological information about the valence quarks, we concluded that this correlation is negative, meaning that the valence quark spin and kinetic orbital angular momentum are, in average, opposite. The quark spin-orbit correlation can also be expressed more intuitively in terms of relativistic phase-space distributions, which can be seen as the mother distributions of the standard generalized and transverse-momentum dependent parton distributions. We present here for the first time some examples of the general multipole decomposition of these phase-space distributions.

  11. ORBITAL MANIFESTATIONS OF SINUS DISEASE

    Directory of Open Access Journals (Sweden)

    Jyothirmayi

    2015-01-01

    Full Text Available AIM : To study the orbital manifestations in patients with sinus disease. METHODS : Patients wit h paranasal sinus disease presenting to OPD at Government ENT Hospital, AMC, Visakhapatnam from January 2012 to June 2014 were screened for orbital manifestations. Out of these, thirteen patients with orbital disease were referred to GREH, AMC, Visakhapatn am and were thoroughly investigated and managed appropriately. RESULTS : Out of the 14 patients 4 were female and 10 were male. Age ranged from 19 years to 70 years. 5 had maxillary sinus disease (4 - carcinoma and 1 case of mucormycosis. Frontal sinus dis ease was seen in two patients, one fibrous dysplasia and one malignancy. Five patients had ethmoidal sinus disease of which three patients were found to have ethmoidal sinus tumour (Malignant melanoma, Squamous cell Carcinoma. More than two sinuses were i nvolved in 2 patients. CONCLUSIONS : Early screening of patients with sinus disease by an Ophthalmologist can help in preventing severe vision threatening orbital complications.

  12. Closed Orbits in Phase Space

    Science.gov (United States)

    Murphy, Andrew; Haestad, Jace; Morgan, Thomas

    2015-09-01

    We report characteristics of closed classical orbits in an electric field in phase space produced in photoabsorption. Rydberg states of atomic and molecular hydrogen and helium are considered. The core potential used for the hydrogen molecule is an effective one electron one center core potential evaluated at the internuclear equilibrium distance. Poincare surfaces of section in phase space are generated by integrating the equations of motion in semiparabolic coordinates u = (r + z) 1 / 2 and v = (r - z) 1 / 2, and plotting the location in phase space (pv versus v) whenever u = 0, with the electric field in the z direction. Combination orbits produced by Rydberg electron core scattering are studied and the evolution in phase space of these combination orbits due to scattering from one closed orbit into another is investigated. Connections are made to measured laser photoabsorption experiments that excite Rydberg states (20 recurrence spectra. The phase space structures responsible for the spectra are identified.

  13. A Case of Orbital Histoplasmosis.

    Science.gov (United States)

    Krakauer, Mark; Prendes, Mark Armando; Wilkes, Byron; Lee, Hui Bae Harold; Fraig, Mostafa; Nunery, William R

    2016-01-01

    Histoplasma capsulatum var capsulatum is a dimorphic fungus endemic to the Ohio and Mississippi River Valleys of the United States. In this case report, a 33-year-old woman who presented with a right orbital mass causing progressive vision loss, diplopia, and facial swelling is described. Lateral orbitotomy with lateral orbital wall bone flap was performed for excisional biopsy of the lesion. The 1.5 × 1.8 × 2.3 cm cicatricial mass demonstrated a granulomatous lesion with necrosis and positive staining consistent with Histoplasma capsulatum var capsulatum infection. To the authors' knowledge, this is the first case of orbital histoplasmosis to be reported in the United States and the first case worldwide of orbital histoplasmosis due to Histoplasma capsulatum var capsulatum.

  14. Formation around planetary displaced orbit

    Institute of Scientific and Technical Information of China (English)

    GONG Sheng-ping; LI Jun-feng; BAOYIN He-xi

    2007-01-01

    The paper investigates the relative motion around the planetary displaced orbit. Several kinds of displaced orbits for geocentric and martian cases were discussed. First, the relative motion was linearized around the displaced orbits. Then, two seminatural control laws were investigated for each kind of orbit and the stable regions were obtained for each case. One of the two control laws is the passive control law that is very attractive for engineering practice. However, the two control laws are not very suitable for the Martian mission. Another special semi-natural control law is designed based on the requirement of the Martian mission. The results show that large stable regions exist for the control law.

  15. Orbital entanglement in quantum chemistry

    CERN Document Server

    Boguslawski, Katharina

    2014-01-01

    The basic concepts of orbital entanglement and its application to chemistry are briefly reviewed. The calculation of orbital entanglement measures from correlated wavefunctions is discussed in terms of reduced $n$-particle density matrices. Possible simplifications in their evaluation are highlighted in case of seniority-zero wavefunctions. Specifically, orbital entanglement allows us to dissect electron correlation effects in its strong and weak contributions, to determine bond orders, to assess the quality and stability of active space calculations, to monitor chemical reactions, and to identify points along the reaction coordinate where electronic wavefunctions change drastically. Thus, orbital entanglement represents a useful and intuitive tool to interpret complex electronic wavefunctions and to facilitate a qualitative understanding of electronic structure and how it changes in chemical processes.

  16. How to Orbit the Earth.

    Science.gov (United States)

    Quimby, Donald J.

    1984-01-01

    Discusses the geometry, algebra, and logic involved in the solution of a "Mindbenders" problem in "Discover" magazine and applies it to calculations of satellite orbital velocity. Extends the solution of this probe to other applications of falling objects. (JM)

  17. Orbital mechanics near Lagrange's points

    OpenAIRE

    Utashima, Masayoshi; 歌島 昌由

    1997-01-01

    The first libration-point satellite ISEE-3 (International Sun-Earth Explorer-3) was launched in 1978. Though, no libration-point satellites were realized after the launch of the ISEE-3, NASA launched the ESA's Solar and Heliospheric Observatory (SOHO) spacecraft into the halo orbit in the sun-earth system in late 1995. The halo orbit in the sun-earth system is adequate for missions such as solar observation, astronomical observation, NEO (Near Earth Objects) observation, communications with t...

  18. Orbit Determination Analysis for SSAPurposes

    OpenAIRE

    2015-01-01

    Space Situational Awareness (SSA) is the characterization of the space environmentand of space activities. The fundament of SSA is the access to information about theorbit of space objects. There exist several techniques to determine the orbit of objects inspace, both from space-based and from ground-based observations. This Master's Thesisproject aims at investigating orbit determinations from ground-based radar observations.In particular, the use of the EISCAT Ultra-High-Frequency (UHF) inc...

  19. Orbits in a logarithmic potential

    Energy Technology Data Exchange (ETDEWEB)

    Hooverman, R. H.

    2014-04-15

    The characteristics of charged particle orbits in the logarithmic electrostatic potential field surrounding a straight conducting wire at a fixed potential are investigated. The equations of motion of an electron in a logarithmic potential are derived, the limiting cases are considered, and the results of numerical integration of the equations of motion are presented along with sketches of a few representative orbits. (C.E.S.)

  20. Diplopia and orbital wall fractures.

    Science.gov (United States)

    Boffano, Paolo; Roccia, Fabio; Gallesio, Cesare; Karagozoglu, K Hakki; Forouzanfar, Tymour

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and such fractures. This study is based on 2 databases that have continuously recorded data of patients hospitalized with maxillofacial fractures between 2001 and 2010. On the whole, 447 patients (334 males, 113 females) with pure blow-out orbital wall fractures were included. The most frequently involved orbital site was the floor (359 fractures), followed by medial wall (41 fractures) and lateral wall (5 fractures). At presentation, 227 patients (50.7%) had evidence of diplopia. In particular, in most patients, a diplopia in all directions was referred (78 patients). Statistically significant associations were found between diplopia on eye elevation and orbital floor fractures (P diplopia and medial wall fractures (P diplopia on eye elevation and horizontal diplopia at presentation could be useful clinical indicators orbital floor and medial wall fractures, respectively.

  1. 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.

  2. Low Earth orbit communications satellite

    Science.gov (United States)

    Moroney, D.; Lashbrook, D.; Mckibben, B.; Gardener, N.; Rivers, T.; Nottingham, G.; Golden, B.; Barfield, B.; Bruening, J.; Wood, D.

    1992-01-01

    A current thrust in satellite communication systems considers a low-Earth orbiting constellations of satellites for continuous global coverage. Conceptual design studies have been done at the time of this design project by LORAL Aerospace Corporation under the program name GLOBALSTAR and by Motorola under their IRIDIUM program. This design project concentrates on the spacecraft design of the GLOBALSTAR low-Earth orbiting communication system. Overview information on the program was gained through the Federal Communications Commission licensing request. The GLOBALSTAR system consists of 48 operational satellites positioned in a Walker Delta pattern providing global coverage and redundancy. The operational orbit is 1389 km (750 nmi) altitude with eight planes of six satellites each. The orbital planes are spaced 45 deg., and the spacecraft are separated by 60 deg. within the plane. A Delta 2 launch vehicle is used to carry six spacecraft for orbit establishment. Once in orbit, the spacecraft will utilize code-division multiple access (spread spectrum modulation) for digital relay, voice, and radio determination satellite services (RDSS) yielding position determination with accuracy up to 200 meters.

  3. Orbital Volumetry in Graves' Orbitopathy

    DEFF Research Database (Denmark)

    Al-Bakri, Moug; Rasmussen, Åse Krogh; Thomsen, Carsten

    2014-01-01

    .6 cm(3) in controls, 8.7 ± 8.0 cm(3) in GO without DON, and 9.4 ± 3.1 cm(3) in GO with DON. The muscle and fat volumes were higher in patients with GO than in controls (P orbits with and without DON were not significantly different. The volume of the optic nerve were...... similar in the 3 groups. The number of apical, coronal 2 mm thick slices with no fat was 2.9 ± 0.9 in normal orbits, it was 4.1 ± 1.0 in GO orbits without DON and 5.3 ± 0.8 in GO orbits with DON (P = 0.007). Conclusion. Apical muscle enlargement may be more important than orbital fat enlargement......Purpose. We wanted to investigate the relative significance of fat and muscle enlargement in the development of dysthyroid optic neuropathy (DON) in Graves' orbitopathy (GO). Methods. Preoperative coronal CT scans of 13 patients with and without DON who subsequently underwent orbital decompression...

  4. 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

  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. Orbit graphs and face-transitivity of k-orbit polytopes

    OpenAIRE

    Cunningham, Gabe

    2012-01-01

    The orbit graph of a k-orbit polytope is a graph on k nodes that shows how the flag orbits are related by flag adjacency. Using orbit graphs, we classify k-orbit polytopes and determine when a k-orbit polytope is i-transitive. We then provide an explicit classification of three-orbit polytopes, and we describe a generating set for their automorphism groups.

  7. Tumor pathology of the orbit.

    Science.gov (United States)

    Héran, F; Bergès, O; Blustajn, J; Boucenna, M; Charbonneau, F; Koskas, P; Lafitte, F; Nau, E; Roux, P; Sadik, J C; Savatovsky, J; Williams, M

    2014-10-01

    The term orbital tumor covers a wide range of benign and malignant diseases affecting specific component of the orbit or developing in contact with them. They are found incidentally or may be investigated as part of the assessment of a systemic disorder or because of orbital signs (exophthalmos, pain, etc.). Computed tomography, MRI and Color Doppler Ultrasound (CDU), play a varying role depending on the clinical presentation and the disease being investigated. This article reflects long experience in a reference center but does not claim to be exhaustive. We have chosen to consider these tumors from the perspective of their usual presentation, emphasizing the most common causes and suggestive radiological and clinical presentations (progressive or sudden-onset exophthalmos, children or adults, lacrimal gland lesions, periorbital lesions and enophthalmos). We will describe in particular muscle involvement (thyrotoxicosis and tumors), vascular lesions (cavernous sinus hemangioma, orbital varix, cystic lymphangioma), childhood lesions and orbital hematomas. We offer straightforward useful protocols for simple investigation and differential diagnosis. Readers who wish to go further to extend their knowledge in this fascinating area can refer to the references in the bibliography.

  8. First Spacecraft Orbit of Mercury

    Science.gov (United States)

    Showstack, Randy

    2011-03-01

    After a 7.9-billion-kilometer flight since its launch on 3 August 2004—which included flybys of Earth, Venus, and Mercury—NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft entered a planned, highly elliptical orbit around the closest planet to our Sun on 17 March. Engineers in the mission operations center at the Johns Hopkins University Applied Physics Laboratory (JHU/APL) in Laurel, Md., which manages the mission for NASA, received radiometric signals indicating a successful orbit insertion at 9:10 P.M. local time. "Tonight we will have orbited the fifth planet in the solar system. This is a major accomplishment," Ed Weiler, NASA assistant administrator for the Science Mission Directorate, said at a 17 March public forum at JHU/APL, noting that spacecraft have previously entered orbit around several other planets. "You only go into orbit for the first time around Mercury once in human history, and that is what was accomplished tonight."

  9. 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

  10. 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.

  11. MRI of orbital hydroxyapatite implants

    Energy Technology Data Exchange (ETDEWEB)

    Flanders, A.E. [Dept. of Radiology, Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States); De Potter, P. [Dept. of Ophthalmology, Wills Eye Inst., Philadelphia, PA (United States); Rao, V.M. [Dept. of Radiology, Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States); Tom, B.M. [Dept. of Radiology, Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States); Shields, C.L. [Dept. of Ophthalmology, Wills Eye Inst., Philadelphia, PA (United States); Shields, J.A. [Dept. of Ophthalmology, Wills Eye Inst., Philadelphia, PA (United States)

    1996-04-01

    Our aim was to use MRI for the postsurgical assessment of a new form of integrated orbital implant composed of a porous calcium phosphate hydroxyapatite substrate. We studied ten patients 24-74 years of age who underwent enucleation and implantation of a hydroxyapatite ball; 5-13 months after surgery, each patient was examined by spin-echo MRI, with fat suppression and gadolinium enhancement. Fibrovascular ingrowth was demonstrated in all ten patients as areas of enhancement at the periphery of the hydroxyapatite sphere that extended to the center to a variable degree. The radiologist should aware of the MRI appearances of the coralline hydroxyapatite orbital implant since it is now widely used following enucleation. MRI is a useful means to determine successful incorporation of the substrate into the orbital tissues. The normal pattern of contrast enhancement should not be mistaken for recurrent tumor or infection. (orig.)

  12. Orbital Evolution of 4179 Toutatis

    CERN Document Server

    Siregar, Suryadi

    2013-01-01

    Asteroid 1934 CT;1989 AC, well known as 4179 Toutatis, is an Apollo and Mars-crosser asteroid with a chaotic orbit produced by a 3:1 resonance with Jupiter and a 1:4 resonance with the Earth, and frequent close approaches to the Earth. It is listed as a potential hazardous object (PHA). The aim of this study is to investigate the possibility of 4179 Toutatis to be ejected from the Solar System. This paper presents an orbital evolution of 4179 Toutatis in time interval of ~300 kyr. Investigation of its orbital evolution is conducted by using the Mercury subroutine package, where the gravitational perturbations of eight major planets in the Solar System are considered. Over very short time scales (~300 kyr) relative to the Solar System life time (~10 Gyr), the asteroid 4179 Toutatis gave an example of chaotic motion that can cause asteroid to move outward and may be followed by escaping from the Solar System.

  13. Oncocytic Adenocarcinoma of the Orbit.

    Science.gov (United States)

    Harris, Gerald J; Paul, Sean; Hunt, Bryan C

    Oncocytic adenocarcinoma of the orbit is a rare tumor, with 1 case of nonlacrimal sac, nonlacrimal gland origin, and a poor outcome previously reported. An 85-year-old man with a 2-month history of left-sided epiphora, enlarging eyelid nodules, and diplopia in left gaze was found on imaging to have a poorly circumscribed, nodular mass of uniform radiodensity in the inferomedial orbit. Incisional biopsy revealed morphologic and immunohistochemical features of oncocytic adenocarcinoma with origin in the caruncle suspected, and CT of the neck, chest, abdomen, and pelvis showed no metastases or remote primary tumor source. Based on multidisciplinary consensus, orbital exenteration with adjuvant radiation therapy was performed, and there was no evidence of residual or recurrent tumor 2 years after treatment.

  14. Multiple Myeloma of the Orbit

    Directory of Open Access Journals (Sweden)

    Mona Hassan

    2012-01-01

    Full Text Available The authors report a case of a 62-year-old female with history of multiple myeloma who presents with complains of swelling and pain in her right eye. On examination, it was found that she has proptosis, chemosis, and diplopia along with decreased vision. Initial workup and treatment did not yield significant results, eventually she was found to have myelomatous changes in her right orbit on MRI and was diagnosed with multiple myeloma of the orbit which resolved solely with radiation. This case tends to highlight the importance of considering myeloma of the orbit as a very important and early differential diagnosis in a patient with a history of multiple myeloma presenting with a swollen and painful eye.

  15. GridOrbit public display

    DEFF Research Database (Denmark)

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

    2010-01-01

    We introduce GridOrbit, a public awareness display that visualizes the activity of a community grid used in a biology laboratory. This community grid executes bioin-formatics algorithms and relies on users to donate CPU cycles to the grid. The goal of GridOrbit is to create a shared awareness about...... 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....

  16. Orbital computed tomography for exophthalmos

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ok Keun; Lee, Hyun; Sol, Chang Hyo; Kim, Byung Soo [College of Medicine, Pusan National University, Busan (Korea, Republic of)

    1987-06-15

    Since exophthalmos is caused by any decrease in the size of bony orbit or occurrence of mass within the rigid orbit, the accurate diagnosis of its causes are essential in determining the therapeutic aims. Exophthalmos is one of the important signs being the indication for orbital computed tomography along with periorbital swelling, visual loss, orbital trauma and diplopia. CT as the diagnostic tool for the cause of exophthalmos not only displays a superb role with uncomparable quality in comparison to any conventional diagnostic methods but also has a decisive role in determining the therapeutic aims and the appropriate operative method when the operation is indicated. The orbital CT was performed from May in 1983 to May in 1985 whose with chief complaints were exophthalmos and 23 cases were confirmed by operation, biopsy, clinical progression or other diagnostic procedures. Here was report thoroughly analyzed 23 cases. The results were as follows : 1. The etiologic disease of exophthalmos were 6 cases of pseudotumor, 4 cases of thyroid ophthalmopathy, 4 cases of maxill ary sinus and nasal cavity Ca., 3 cases of mucocele and 1 case of alveolar soft part sarcoma, osteoma, dermoid cyst, pleomorphic adenoma, meningioma, and C.C.F. each. 2. The origin of the etiologic diseases of exophthalmos were 13 cases of primary within bony orbit and 10 cases of secondary from adjacent structure. 3. The site of lesions were 11 cases of intraconal and extraconal, 10 cases of extraconal, and 2 cases of intraconal origin. 4. The degree of exophthalmos in CT scan was in proportion to the volume of the mass except in the case of thyroid ophthalmopathy. The upper limit of normal range by CT scan using regression line equation was 16.2 mm in approximation. 5. CT was a very useful diagnostic tool in the accurate assessment of the kinds of lesion, its location, and its relationship to adjacent structures in the diagnosis of etiologic diseases of exophthalmos.

  17. Energy and the Elliptical Orbit

    Science.gov (United States)

    Nettles, Bill

    2009-03-01

    In the January 2007 issue of The Physics Teacher, Prentis, Fulton, Hesse, and Mazzino describe a laboratory exercise in which students use a geometrical analysis inspired by Newton to show that an elliptical orbit and an inverse-square law force go hand in hand. The historical, geometrical, and teamwork aspects of the exercise are useful and important. This paper presents an exercise which uses an energy/angular momentum conservation model for elliptical orbits. This exercise can be done easily by an individual student and on regular notebook-sized paper.

  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, 8010045

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. Primary orbital squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Ana L. Campos Arbulú

    2017-02-01

    Full Text Available Primary orbital squamous cell carcinoma is a rare entity. There is little published literature. We report a case of primary squamous cell carcinoma of the orbital soft tissues. Surgical resection offered the best treatment for the patient. Complete resection of the lesion was achieved. The patient received adjuvant radiotherapy due to the proximity of the lesion to the surgical margins. Surgical treatment is feasible and should be considered as part of the surgeon's arsenal. However, therapeutic decisions must be made on a case-by-case basis

  4. Nodular Fasciitis of the Orbit.

    Science.gov (United States)

    Compton, Christopher J; Clark, Jeremy D; Thompson, Matthew P; Lee, Hui Bae H; Nunery, William R

    A 13-month-old boy was presented with new onset proptosis of the right eye. CT scan and MRI showed an enhancing mass in the right superior orbit with local bone remodeling and erosion. A craniotomy was performed for biopsy and sub-total resection. Histopathology and immunohistochemistry confirmed the lesion to be nodular fasciitis. Nodular fasciitis lesions are classically found in the anterior ocular adnexa, especially in pediatric patients. This is the first reported case of nodular fasciitis arising in the posterior orbit of a child younger than 16.

  5. Precision Orbit Determination for the Lunar Reconnaissance Orbiter: orbit quality and gravity field estimation

    Science.gov (United States)

    Mazarico, E.; Rowlands, D. D.; Neumann, G. A.; Lemoine, F. G.; Torrence, M. H.; Smith, D. E.; Zuber, M. T.; Mao, D.

    2010-12-01

    We present results of the Precision Orbit Determination work undertaken by the Lunar Orbiter Laser Altimeter (LOLA) Science Team for the Lunar Reconnaissance Orbiter (LRO) mission, in order to meet the position knowledge accuracy requirements (50-m total position) and to precisely geolocate the LRO datasets. In addition to the radiometric tracking data, one-way laser ranges (LR) between Earth stations and the spacecraft are made possible by a small telescope mounted on the spacecraft high-gain antenna. The photons received from Earth are transmitted to one LOLA detector by a fiber optics bundle. The LOLA timing system enables 5-s LR normal points with precision better than 10cm. Other types of geodetic constraints are derived from the altimetric data itself. The orbit geometry can be constrained at the times of laser groundtrack intersections (crossovers). Due to the Moon's slow rotation, orbit solutions and normal equations including altimeter crossovers are processed and created in one month batches. Recent high-resolution topographic maps near the lunar poles are used to produce a new kind of geodetic constraints. Purely geometric, those do not necessitate actual groundtrack intersections. We assess the contributions of those data types, and the quality of our orbits. Solutions which use altimetric crossover meet the horizontal 50-m requirement, and perform usually better (10-20m). We also obtain gravity field solutions based on LRO and historical data. The various LRO data are accumulated into normal equations, separately for each one month batch and for each measurement type, which enables the final weights to be adjusted during the least-squares inversion step. Expansion coefficients to degree and order 150 are estimated, and a Kaula rule is still needed to stabilize the farside field. The gravity field solutions are compared to previous solutions (GLGM-3, LP150Q, SGM100h) and the geopotential predicted from the latest LOLA spherical harmonic expansion.

  6. 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.

  7. 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

  8. Three planets orbiting Wolf 1061

    CERN Document Server

    Wright, D J; Tinney, C G; Bentley, J S; Zhao, Jinglin

    2015-01-01

    We use archival HARPS spectra to detect three planets orbiting the M3 dwarf Wolf1061 (GJ 628). We detect a 1.36 Mearth minimum-mass planet with an orbital period P = 4.888d (Wolf1061b), a 4.25 Mearth minimum-mass planet with orbital period P = 17.867d (Wolf1061c), and a likely 5.21 Mearth minimum-mass planet with orbital period P = 67.274d (Wolf1061d). All of the planets are of sufficiently low mass that they may be rocky in nature. The 17.867d planet falls within the habitable zone for Wolf 1061 and the 67.274d planet falls just outside the outer boundary of the habitable zone. There are no signs of activity observed in the bisector spans, cross-correlation full-width-half-maxima, Calcium H & K indices, NaD indices, or H-alpha 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 exploi...

  9. 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.

  10. Myeloid Sarcoma in the Orbit.

    Science.gov (United States)

    Qian, Xiaoxiao; Gigantelli, James W; Abromowitch, Minnie; Morgan, Linda A; Suh, Donny W

    2016-12-08

    The authors describe a case of myeloid sarcoma of the orbit in a pediatric patient. An 8-month-old male infant presented to the ophthalmology clinic with a left orbital mass, which had been increasing in size over the previous 2 months. The mass was initially diagnosed at another clinic as an infantile hemangioma, and had been treated with a topical formulation of timolol. In the ophthalmology clinic, orbital magnetic resonance imaging showed a solid enhancing mass. A biopsy was performed, and histopathology revealed myeloid sarcoma. The disease responded well to a standard chemotherapy regimen. Myeloid sarcoma is a rare, extra-medullary presentation that can occur as an isolated tumor, concurrently with or at relapse of acute myeloid leukemia. Because few cases of myeloid sarcoma in the orbit have been reported, this case report aids in the management of myeloid sarcoma in pediatric patients. The report describes an 8-month-old male infant, the youngest patient to develop myeloid sarcoma without preexisting acute myeloid leukemia. [J Pediatr Ophthalmol Strabismus. 2016;53:e64-e68.].

  11. 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…

  12. Energy and the Elliptical Orbit

    Science.gov (United States)

    Nettles, Bill

    2009-01-01

    In the January 2007 issue of "The Physics Teacher," Prentis, Fulton, Hesse, and Mazzino describe a laboratory exercise in which students use a geometrical analysis inspired by Newton to show that an elliptical orbit and an inverse-square law force go hand in hand. The historical, geometrical, and teamwork aspects of the exercise are useful and…

  13. Removing Orbital Debris with Lasers

    CERN Document Server

    Phipps, Claude R; Bradford, Brian; George, E Victor; Libby, Stephen B; Liedahl, Duane A; Marcovici, Bogdan; Olivier, Scot S; Pleasance, Lyn D; Reilly, James P; Rubenchik, Alexander; Strafford, David N; Valley, Michael T

    2011-01-01

    Orbital debris in low Earth orbit (LEO) are now sufficiently dense that the use of LEO space is threatened by runaway collisional cascading. A problem predicted more than thirty years ago, the threat from debris larger than about 1 cm demands serious attention. A promising proposed solution uses a high power pulsed laser system on the Earth to make plasma jets on the objects, slowing them slightly, and causing them to re-enter and burn up in the atmosphere. In this paper, we reassess this approach in light of recent advances in low-cost, light-weight modular design for large mirrors, calculations of laser-induced orbit changes and in design of repetitive, multi-kilojoule lasers, that build on inertial fusion research. These advances now suggest that laser orbital debris removal (LODR) is the most cost-effective way to mitigate the debris problem. No other solutions have been proposed that address the whole problem of large and small debris. A LODR system will have multiple uses beyond debris removal. Internat...

  14. 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.

  15. NATO: In-orbit experience

    Science.gov (United States)

    Capulli, J. J.

    1980-01-01

    The performance of the NATO-111-A and NATO 111-B satellite battery is reported. The electrical power subsystem is briefly described. The electrical characteristics and the reconditioning experience of the batteries is cited. The in-orbit experience is compared with results of preflight accelerated life tests.

  16. Shadowing Lemma and Chaotic Orbit Determination

    CERN Document Server

    Spoto, Federica

    2015-01-01

    Orbit determination is possible for a chaotic orbit of a dynamical system, given a finite set of observations, provided the initial conditions are at the central time. In a simple discrete model, the standard map, we tackle the problem of chaotic orbit determination when observations extend beyond the predictability horizon. If the orbit is hyperbolic, a shadowing orbit is computed by the least squares orbit determination. We test both the convergence of the orbit determination iterative procedure and the behaviour of the uncertainties as a function of the maximum number $n$ of map iterations observed. When the initial conditions belong to a chaotic orbit, the orbit determination is made impossible by numerical instability beyond a computability horizon, which can be approximately predicted by a simple formula. Moreover, the uncertainty of the results is sharply increased if a dynamical parameter is added to the initial conditions as parameter to be estimated. The uncertainty of the dynamical parameter decrea...

  17. The globe and orbit in Laron syndrome.

    Science.gov (United States)

    Kornreich, L; Konen, O; Lilos, P; Laron, Z

    2011-09-01

    Patients with LS have an inborn growth hormone resistance, resulting in failure to generate IGF-1. The purpose of this study was to evaluate the size of the eye and orbit in LS. We retrospectively reviewed the MR imaging of the brain in 9 patients with LS for the following parameters: axial diameter of the globe, interzygomatic distance, perpendicular distance from the interzygomatic line to margins of the globe, medial-to-lateral diameter of the orbit at the anterior orbital rim, distance from the anterior orbital rim to the anterior globe, maximal distance between the medial walls of the orbits, lateral orbital wall angle, lateral orbital wall length, and mediolateral thickness of the intraorbital fat in the most cranial image of the orbit. All measurements were made bilaterally. Twenty patients referred for MR imaging for unrelated reasons served as control subjects. Compared with the control group, the patients with LS had a significantly smaller maximal globe diameter and shallower but wider orbits due to a shorter lateral wall, a smaller medial distance between the orbits, and a larger angle of the orbit. The ratio between the most anterior orbital diameter and the globe was greater than that in controls. The position of the globe was more anterior in relation to the interzygomatic line. Shallow and wide orbits and small globes relative to orbital size are seen in LS and may be secondary to IGF-1 deficiency.

  18. [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.

  19. 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.

  20. 'Orbital volume restoration rate after orbital fracture'; a CT-based orbital volume measurement for evaluation of orbital wall reconstructive effect.

    Science.gov (United States)

    Wi, J M; Sung, K H; Chi, M

    2017-01-13

    PurposeTo evaluate the effect of orbital reconstruction and factors related to the effect of orbital reconstruction by assessing of orbital volume using orbital computed tomography (CT) in cases of orbital wall fracture.MethodsIn this retrospective study, 68 patients with isolated blowout fractures were evaluated. The volumes of orbits and herniated orbital tissues were determined by CT scans using a three-dimensional reconstruction technique (the Eclipse Treatment Planning System). Orbital CT was performed preoperatively, immediately after surgery, and at final follow ups (minimum of 6 months). We evaluated the reconstructive effect of surgery making a new formula, 'orbital volume reconstruction rate' from orbital volume differences between fractured and contralateral orbits before surgery, immediately after surgery, and at final follow up.ResultsMean volume of fractured orbits before surgery was 23.01±2.60 cm(3) and that of contralateral orbits was 21.31±2.50 cm(3) (P=0.005). Mean volume of the fractured orbits immediately after surgery was 21.29±2.42 cm(3), and that of the contralateral orbits was 21.33±2.52 cm(3) (P=0.921). Mean volume of fractured orbits at final follow up was 21.50±2.44 cm(3), and that of contralateral orbits was 21.32±2.50 cm(3) (P=0.668). The mean orbital volume reconstruction rate was 100.47% immediately after surgery and 99.17% at final follow up. No significant difference in orbital volume reconstruction rate was observed with respect to fracture site or orbital implant type. Patients that underwent operation within 14 days of trauma had a better reconstruction rate at final follow up than patients who underwent operation over 14 days after trauma (P=0.039).ConclusionComputer-based measurements of orbital fracture volume can be used to evaluate the reconstructive effect of orbital implants and provide useful quantitative information. Significant reduction of orbital volume is observed immediately after orbital wall

  1. [Rhino-orbital mucormycosis with orbital abscess: a case report].

    Science.gov (United States)

    Tatar, Emel Cadallı; Sürenoğlu, Unzile Akpınar; Işık, Eray; Tütüncü, Ediz; Korkmaz, Hakan

    2011-01-01

    Sinonasal mucormycosis is a rare, life-threatening and insidious fungal infection. Uncontrolled diabetes mellitus and immunsupression are the most important risk factors. The infection is clinically characterized by black necrotic tissues and crusting in the nasal cavity. In acute fulminant rhinosinusitis and particularly in infections caused by mucor species, black scar tissues seen on the nasal mucosa are pathognomonic. High level of suspicion in the risk group the diagnosis is confirmed by histopathological examination. The rhinoorbital form is even rarer and the findings may range from orbital pain to ophtalmoplegia and blindness. In this report we present a 72-year-old female patient with uncontrolled type 2 diabetes mellitus who was admited with the complaints of exophtalmos in the left eye, diplopia and headache. In the physical examination there was purulent discharge in the middle meatus and left orbital abscess was detected on computed tomography. We performed an emergency endoscopic sinus surgery. While we did not observe any necrotic tissues, granulation tissues were detected and pus was drained from the orbital cavity. The result of the histopathological examination was reported as invasive mucormycosis. We presented this case to emphasize the importance of early diagnosis and treatment of rhinoorbital mucormycosis.

  2. 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 a

  3. 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.

  4. Overview of the Mars Reconnaissance Orbiter mission

    Science.gov (United States)

    Mateer, B.; Graf, J.; Zurek, R.; Jones, R.; Eisen, H.; Johnston, M.; Jai, D. B.

    2002-01-01

    The Mars Reconnaissance Orbiter will deliver to Mars orbit a payload to conduct remote sensing science observations, characterize sites for future landers, and provide critical telecom/navigation relay capability for follow-on missions.

  5. Tumors of the orbit; Orbitatumoren

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Forell, Wibke [Klinikum der Univ. Mainz (Germany). Inst. fuer Neuroradiologie

    2008-09-15

    This short review will present an overview not only of the findings in imaging, but the main clinical symptoms of the different orbital space occupying lesions, (not only different tumors, but even tumor-like lesions), as those should be included in differential diagnostic consideration. This should lead to a targeted diagnostic procedure in the individual patient. Basic knowledge of orbital anatomy is as important as the knowledge of the pros and contra's of computed tomography (CT) and magnetic resonance imaging (MRI), which should influence the examination protocol. Imaging findings of the most important tumors/lesions of the globe, the intraconal and extraconal space as well as of the optic nerve are presented with different examples (without any demand of completeness). (orig.)

  6. 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.

  7. 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.

  8. The rehybridization of electronic orbitals in carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    Ouyang Yu; Peng Jing-Cui; Wang Hui; Peng Zhi-Hua

    2008-01-01

    Rehybridization of electronic orbitals in carbon nanotubes contains tilting angles of π orbital, electrons wavefunc-tions of π orbital and σ orbital, degrees of hybridization, etc. In this paper, we have obtained analytical formulas of tilting angle of π orbital relative to tube surface, electrons wavefunctions of π orbital and σ orbital, degrees of hybridization, separately, as well as the numerical results.

  9. Anteromedial Approach to the Orbit

    OpenAIRE

    DEDA, Haluk; Ugur, Hasan Çaglar; Yorulmaz, Irfan; Kucuk, Babur

    2001-01-01

    This study evaluated the surgical results of the anteromedial approach for treatment of orbital lesions in 16 patients. Pre- and postoperatively, all patients underwent a complete physical examination focusing on the head and neck area including a thorough ophthalmologic evaluation, computerized tomography, and magnetic resonance imaging. The surgical approach was limited to a medial orbitotomy in five patients; the remaining 11 patients underwent a medial orbitotomy combined with an external...

  10. 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.

  11. Understanding pediatric bacterial preseptal and orbital cellulitis

    Directory of Open Access Journals (Sweden)

    Gonzalez Mithra

    2010-01-01

    Full Text Available 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.

  12. Spin-orbit ferromagnetic resonance

    Science.gov (United States)

    Ferguson, Andrew

    2013-03-01

    In conventional magnetic resonance techniques the magnitude and direction of the oscillatory magnetic field are (at least approximately) known. This oscillatory field is used to probe the properties of a spin ensemble. Here, I will describe experiments that do the inverse. I will discuss how we use a magnetic resonance technique to map out the current-induced effective magnetic fields in the ferromagnetic semiconductors (Ga,Mn)As and (Ga,Mn)(As,P). These current-induced fields have their origin in the spin-orbit interaction. Effective magnetic fields are observed with symmetries which resemble the Dresselhaus and Rashba spin-orbit interactions and which depend on the diagonal and off-diagonal strain respectively. Ferromagnetic semiconductor materials of different strains, annealing conditions and concentrations are studied and the results compared with theoretical calculations. Our original study measured the rectification voltage coming from the product of the oscillatory magnetoresistance, during magnetisation precession, and the alternating current. More recently we have developed an impedance matching technique which enables us to extract microwave voltages from these high resistance (10 k Ω) samples. In this way we measure the microwave voltage coming from the product of the oscillating magneto-resistance and a direct current. The direct current is observed to affect the magnetisation precession, indicating that anti-damping as well as field-like torques can originate from the spin-orbit interaction.

  13. Proxima's orbit around Alpha Centauri

    CERN Document Server

    Kervella, P

    2016-01-01

    Proxima and Alpha Centauri AB have almost identical distances and proper motions with respect to the Sun. Although the probability of such similar parameters is in principle very low, the question whether they actually form a single gravitationally bound triple system has been open since the discovery of Proxima one century ago. Owing to recent high precision radial velocity measurements and the revision of the parameters of the Alpha Cen pair, we show that Proxima and Alpha Cen are gravitationally bound with a high degree of confidence. The orbital period of Proxima is approximately 600 000 years, with a moderate excentricity of 0.42 +0.07 -0.08. Proxima comes within 5.3 -0.9 +1.2 kAU of Alpha Cen at periastron, and the apastron occurs at 12.9 +0.3 -0.1 kAU. This orbital motion may have influenced the formation or evolution of the recently discovered planet orbiting Proxima as well as circumbinary planet formation around Alpha Cen.

  14. The geostationary orbit and developing countries

    Science.gov (United States)

    Medina, E. R.

    1982-01-01

    The geostationary orbit is becoming congested due to use by several countries throughout the world, and the request for use of this orbit is increasing. There are 188 geostationary stations in operation. An equitable distribution of stations on this orbit is requested.

  15. Information Measures for Statistical Orbit Determination

    Science.gov (United States)

    Mashiku, Alinda K.

    2013-01-01

    The current Situational Space Awareness (SSA) is faced with a huge task of tracking the increasing number of space objects. The tracking of space objects requires frequent and accurate monitoring for orbit maintenance and collision avoidance using methods for statistical orbit determination. Statistical orbit determination enables us to obtain…

  16. The History of the Molniya Orbit

    Science.gov (United States)

    Kettering Group

    Arthur C. Clarke's name is often linked with the Geostationary orbit as a result of his 1945 paper in Wireless World. Less well-known is where the credit for discovering the Molniya orbit should lie. This paper presents the evidence uncovered to date concerning the original concept and provides some insight into the ways in which the orbit has subsequently been exploited.

  17. Atomic Orbitals for the New Millennium

    CERN Document Server

    Williams, J M

    1999-01-01

    This very short article introduces a set of nested atomic orbitals, called MCAS, to replace the current s, p, d, and f orbitals. The simplest orbital is a tetrahedrally directed, four lobed, mono-orbital instead of the spherical s orbital. All the other orbitals, no matter what their energy (shell) level is, are nested with this one. All the electrons have the same spin and only one electron is allotted to each orbital. Electron spin pairing is accomplished through opposing orbitals instead of actual electron spin reversal. Orbital energy level is maintained by nuclear propulsion through perigee kick. Orbitals hybridize as Aufbau proceeds, in contrast to the inflexible, current building model. The inert gases have completely uniform electronic shells that contain only one orbital type per shell. Since outer completed shells have only one type of orbital, all eight outer electrons are identical rather than being of two types as occurs in the current model; hence, Lewis' electron-dot octet. Hydrogen should resi...

  18. 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

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

    OpenAIRE

    2013-01-01

    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...

  20. A Survey of Research on Service-Spacecraft Orbit Design

    Institute of Scientific and Technical Information of China (English)

    LI Yue; ZHANG Jian-xin; ZHANG Qiang; WEI Xiao-peng

    2013-01-01

    On-orbit service spacecraft orbit problem has been addressed for decades. The research of on-orbit service spacecraft orbit can be roughly divided into orbit design and orbit optimization. The paper mainly focuses on the orbit design problem. We simply summarize of the previous works, and point out the main content of the on-orbit service spacecraft orbit design. We classify current on-orbit service spacecraft orbit design problem into parking-orbit design, maneuvering-orbit design and servicing-orbit design. Then, we give a detail description of the three specific orbits, and put forward our own ideas on the existed achievements. The paper will provide a meaningful reference for the on-orbit service spacecraft orbital design research.

  1. New Orbit Propagator to Be Used in Orbital Debris Evolutionary Models

    OpenAIRE

    Narumi, Tomohiro; Hanada, Toshiya

    2007-01-01

    An orbital environment debris evolutionary model for low Earth orbit has been developed at Kyushu University. A fast orbit propagator is essentially needed in such an evolutionary model because the number of space debris larger than 1 cm in low earth orbit is very large and it takes much time to compute long-term orbital changes of space debris. The effects of orbital perturbations are investigated for hundreds of years, and the rate of change in orbital elements were invented by earlier publ...

  2. Space Shuttle Orbiter auxiliary power unit status

    Science.gov (United States)

    Reck, M.; Loken, G.; Horton, J.; Lukens, W.; Scott, W.; Baughman, J.; Bauch, T.

    An overview of the United States Space Shuttle Orbiter APU, which provides power to the Orbiter vehicle hydraulic system, is presented. Three complete APU systems, each with its own separate fuel system, supply power to three dedicated hydraulic systems. These in turn provide power to all Orbiter vehicle critical flight functions including launch, orbit, reentry, and landing. The basic APU logic diagram is presented. The APU includes a hydrazine-powered turbine that drives a hydraulic pump and various accessories through a high-speed gearbox. The APU also features a sophisticated thermal management system designed to ensure safe and reliable operation in the various launch, orbit, reentry, and landing environments.

  3. Liouville theory and special coadjoint Virasoro orbits

    OpenAIRE

    Gorsky, A.; Johansen, A.

    1993-01-01

    We describe the Hamiltonian reduction of the coajoint Kac-Moody orbits to the Virasoro coajoint orbits explicitly in terms of the Lagrangian approach for the Wess-Zumino-Novikov-Witten theory. While a relation of the coajoint Virasoro orbit $Diff \\; S^1 /SL(2,R)$ to the Liouville theory has been already studied we analyse the role of special coajoint Virasoro orbits $Diff \\; S^1/\\tilde{T}_{\\pm ,n}$ corresponding to stabilizers generated by the vector fields with double zeros. The orbits with ...

  4. Astrometric Determination of VSOP-2 Orbital Parameters

    Science.gov (United States)

    Fomalont, E.; Moellenbrock, G.; Claussen, M.

    2009-08-01

    VSOP-2 phase referencing, needed to image faint sources and to determine accurate positions, will require an orbit accuracy of about 2 cm at 23 GHz. This accuracy, however, may not be obtainable by direct orbital measurements. We propose an observation scheme, similar to that used at the VLBA, to be included during a phase referencing observation of about one orbit in order to determine a more accurate orbit determination. We show the effects of orbit errors, explain the suggested observations and reduction methods, and discuss the potential problems that might impede the use of this technique.

  5. Novel Surgical Approaches to the Orbit.

    Science.gov (United States)

    Campbell, Ashley A; Grob, Seanna R; Yoon, Michael K

    2015-01-01

    Determining safe surgical access to the orbit can be difficult given the complex anatomy and delicacy of the orbital structures. When considering biopsy or removal of an orbital tumor or repair of orbital fractures, careful planning is required to determine the ideal approach. Traditionally, this has at times necessitated invasive procedures with large incisions and extensive bone removal. The purpose of this review was to present newly techniques and devices in orbital surgery that have been reported over the past decade, with aims to provide better exposure and/or minimally invasive approaches and to improve morbidity and/or mortality.

  6. Holonomy invariance, orbital resonances, and kilohertz QPOs

    CERN Document Server

    Abramowicz, M A; Kluzniak, W; Thampan, A V; Wallinder, F

    2002-01-01

    Quantized orbital structures are typical for many aspects of classical gravity (Newton's as well as Einstein's). The astronomical phenomenon of orbital resonances is a well-known example. Recently, Rothman, Ellis and Murugan (2001) discussed quantized orbital structures in the novel context of a holonomy invariance of parallel transport in Schwarzschild geometry. We present here yet another example of quantization of orbits, reflecting both orbital resonances and holonomy invariance. This strong-gravity effect may already have been directly observed as the puzzling kilohertz quasi-periodic oscillations (QPOs) in the X-ray emission from a few accreting galactic black holes and several neutron stars.

  7. The harmonic structure of generic Kerr orbits

    CERN Document Server

    Grossman, Rebecca; Perez-Giz, Gabe

    2011-01-01

    Generic Kerr orbits exhibit intricate three-dimensional motion. We offer a classification scheme for these intricate orbits in terms of periodic orbits. The crucial insight is that for a given effective angular momentum $L$ and angle of inclination $\\iota$, there exists a discrete set of orbits that are geometrically $n$-leaf clovers in a precessing {\\it orbital plane}. When viewed in the full three dimensions, these orbits are periodic in $r-\\theta$. Each $n$-leaf clover is associated with a rational number, $1+q_{r\\theta}=\\omega_\\theta/\\omega_r$, that measures the degree of perihelion precession in the precessing orbital plane. The rational number $q_{r\\theta}$ varies monotonically with the orbital energy and with the orbital eccentricity. Since any bound orbit can be approximated as near one of these periodic $n$-leaf clovers, this special set offers a skeleton that illuminates the structure of all bound Kerr orbits, in or out of the equatorial plane.

  8. Orbital compression syndrome presenting as orbital cellulitis in a child with sickle cell anemia.

    Science.gov (United States)

    Douvoyiannis, Miltiadis; Fakioglu, Esra; Litman, Nathan

    2010-04-01

    Orbital bone infarction with subsequent orbital compression syndrome presenting as orbital cellulitis is reported in a child with sickle cell anemia. She deteriorated despite the use of antibiotics and improved after the surgical drainage of the collection. Radiographic findings, absence of sinusitis, hemorrhagic nature of the collection, and negative cultures all were consistent with orbital compression syndrome secondary to a vasoocclusive crisis. This condition needs to be differentiated from the more common orbital cellulitis secondary to sinusitis.

  9. 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.

  10. 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.

  11. Kepler's Constant and WDS Orbit

    CERN Document Server

    Siregar, S

    2012-01-01

    The aim of this work are to find a Kepler's constant by using polynomial regression of the angular separation \\rho = \\rho(t) and the position angle \\theta = \\theta(t). The Kepler's constant obtained is used to derive the element of orbit. As a case study the angular separation and the position angle of the WDS 00063 +5826 and the WDS 04403-5857 were investigated. For calculating the element of orbit the Thiele-Innes van den Bos method is used. The rough data of the angular separation \\rho(t) and the position angle \\theta(t) are taken from the US Naval Observatory, Washington. This work also presents the masses and absolute bolometric magnitudes of each star.These stars include into the main-sequence stars with the spectral class G5V for WDS04403-5857and the type of spectrum G3V for WDS 00063+5826. The life time of the primary star and the secondary star of WDS 04403-5857 nearly equal to 20 Gyr. The life time of the primary star and the secondary star of WDS 00063+5826 are 20 Gyr and 19 Gyr, respectively.

  12. 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.

  13. 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.

  14. 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. .

  15. Orbital variations, climate and paleoecology.

    Science.gov (United States)

    Bartlein, P J; Prentice, I C

    1989-07-01

    One of the most exciting discoveries in the earth sciences in recent decades has been the proof that ice ages are governed by deterministic variations in the earth's orbit. These variations modify the latitudinal and seasonal distribution of solar radiation at periods ranging from 103 to 10(5) years, and alternately produce conditions for building and melting continental ice. The same solar radiation variations also govern other aspects of world climate, including the temperatures of the midlatitude continental interiors, the intensity of upwelling in the tropical oceans, and the strength and extent of the monsoons. The interplay of solar radiation, seasonality and ice-sheet changes is responsible for the complex ecological history documented in the fossil record of the past 20 000 years. But the orbital variations have occurred throughout earth's history, and have caused periodic environmental changes in both terrestrial and marine environments even during times when there was no ice. Species have responded to these changes by range migration, an evolved ability that may maintain their genetic coherence in the face of a continually changing environment.

  16. LROC - Lunar Reconnaissance Orbiter Camera

    Science.gov (United States)

    Robinson, M. S.; Eliason, E.; Hiesinger, H.; Jolliff, B. L.; McEwen, A.; Malin, M. C.; Ravine, M. A.; Thomas, P. C.; Turtle, E. P.

    2009-12-01

    The Lunar Reconnaissance Orbiter (LRO) went into lunar orbit on 23 June 2009. The LRO Camera (LROC) acquired its first lunar images on June 30 and commenced full scale testing and commissioning on July 10. The LROC consists of two narrow-angle cameras (NACs) that provide 0.5 m scale panchromatic images over a combined 5 km swath, and a wide-angle camera (WAC) to provide images at a scale of 100 m per pixel in five visible wavelength bands (415, 566, 604, 643, and 689 nm) and 400 m per pixel in two ultraviolet bands (321 nm and 360 nm) from the nominal 50 km orbit. Early operations were designed to test the performance of the cameras under all nominal operating conditions and provided a baseline for future calibrations. Test sequences included off-nadir slews to image stars and the Earth, 90° yaw sequences to collect flat field calibration data, night imaging for background characterization, and systematic mapping to test performance. LRO initially was placed into a terminator orbit resulting in images acquired under low signal conditions. Over the next three months the incidence angle at the spacecraft’s equator crossing gradually decreased towards high noon, providing a range of illumination conditions. Several hundred south polar images were collected in support of impact site selection for the LCROSS mission; details can be seen in many of the shadows. Commissioning phase images not only proved the instruments’ overall performance was nominal, but also that many geologic features of the lunar surface are well preserved at the meter-scale. Of particular note is the variety of impact-induced morphologies preserved in a near pristine state in and around kilometer-scale and larger young Copernican age impact craters that include: abundant evidence of impact melt of a variety of rheological properties, including coherent flows with surface textures and planimetric properties reflecting supersolidus (e.g., liquid melt) emplacement, blocks delicately perched on

  17. LLOFX earth orbit to lunar orbit delta V estimation program user and technical documentation

    Science.gov (United States)

    1988-01-01

    The LLOFX computer program calculates in-plane trajectories from an Earth-orbiting space station to Lunar orbit in such a way that the journey requires only two delta V burns (one to leave Earth circular orbit and one to circularize into Lunar orbit). The program requires the user to supply the Space Station altitude and Lunar orbit altitude (in km above the surface), and the desired time of flight for the transfer (in hours). It then determines and displays the trans-Lunar injection (TLI) delta V required to achieve the transfer, the Lunar orbit insertion (LOI) delta V required to circularize the orbit around the Moon, the actual time of flight, and whether the transfer orbit is elliptical or hyperbolic. Return information is also displayed. Finally, a plot of the transfer orbit is displayed.

  18. Analytical representations of precise orbit predictions for Earth orbiting space objects

    Science.gov (United States)

    Sang, Jizhang; Li, Bin; Chen, Junyu; Zhang, Pin; Ning, Jinsheng

    2017-01-01

    Accurate orbits of Earth orbiting space objects are usually generated from an orbit determination/prediction process using numerical integrators, and presented to users in a tabulated form or a state vector including force model parameters. When dealing with hundreds of thousands of space objects such as in the space conjunction assessment, the memory required for the tabulated orbits or the computing time for propagating orbits using the state vector are both confronting to users. This paper presents two methods of analytically representing numerical orbits considering the accuracy, computing efficiency and memory. The first one is a two-step TLE-based method in which the numerical orbits are first fitted into a TLE set and then correction functions are applied to improve the position accuracy. In the second method, the orbit states are represented in equinoctial elements first, and then again correction functions are applied to reduce the position errors. Experiments using six satellite laser ranging (SLR) satellites and 12 debris objects with accurate orbits show that both methods can represent the accurate orbits over 5 days in an accuracy of a few dozens of meters for the circular orbits and several hundred meters for the eccentric orbits. The computing time is similar to that using the NORAD TLE/SGP4 algorithm, and storage for the orbit elements and function coefficients is about 3-5 KB. These features could make the two methods beneficial for the maintenance of orbit catalog of large numbers of space objects.

  19. Homoclinic Bifurcation of Orbit Flip with Resonant Principal Eigenvalues

    Institute of Scientific and Technical Information of China (English)

    Tian Si ZHANG; De Ming ZHU

    2006-01-01

    Codimension-3 bifurcations of an orbit-flip homoclinic orbit with resonant principal eigenvalues are studied for a four-dimensional system. The existence, number, co-existence and non-coexistence of 1-homoclinic orbit, 1-periodic orbit, 2n-homoclinic orbit and 2n-periodic orbit are obtained. The bifurcation surfaces and existence regions are also given.

  20. Degenerate Orbit Flip Homoclinic Bifurcations with Higher Dimensions

    Institute of Scientific and Technical Information of China (English)

    Ran Chao WU; Jian Hua SUN

    2006-01-01

    Bifurcations of a degenerate homoclinic orbit with orbit flip in high dimensional system are existence and uniqueness of 1-homoclinic orbit and 1-periodic orbit are given. Also considered is the existence of 2-homoclinic orbit and 2-periodic orbit. In additon, the corresponding bifurcation surfaces are given.

  1. 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 trajecto...... 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.......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...

  2. Orbital behavior around a nonuniform celestial body

    Science.gov (United States)

    Rosson, Z.; Hall, F.; Vogel, T.

    2016-09-01

    To effectively model the orbit around a nonuniform celestial body, detailed information needs to be determined of the perturbations. This research looked at one of the most crucial perturbations: the nonuniform gravitational field of a celestial body. Given an orbiting particle (a satellite), we utilized numerical methods to calculate its orbit in two dimensions around a discretized center mass structure. The gravitational acceleration imposed on the particle due to each mass point sums vectorally as the particle completes each infinitesimal time step of one orbit. There are noticeable effects on the orbit as the conditions of the center mass change. The development of a simulation code allows for the modelling of the orbit about an irregular body with satisfactory accuracy.

  3. Electronic structure interpolation via atomic orbitals.

    Science.gov (United States)

    Chen, Mohan; Guo, G-C; He, Lixin

    2011-08-17

    We present an efficient scheme for accurate electronic structure interpolation based on systematically improvable optimized atomic orbitals. The atomic orbitals are generated by minimizing the spillage value between the atomic basis calculations and the converged plane wave basis calculations on some coarse k-point grid. They are then used to calculate the band structure of the full Brillouin zone using the linear combination of atomic orbitals algorithms. We find that usually 16-25 orbitals per atom can give an accuracy of about 10 meV compared to the full ab initio calculations, and the accuracy can be systematically improved by using more atomic orbitals. The scheme is easy to implement and robust, and works equally well for metallic systems and systems with complicated band structures. Furthermore, the atomic orbitals have much better transferability than Shirley's basis and Wannier functions, which is very useful for perturbation calculations.

  4. On Orbital Period Changes in Nova Outbursts

    CERN Document Server

    Martin, Rebecca G; Schaefer, Bradley E

    2011-01-01

    We propose a new mechanism that produces an orbital period change during a nova outburst. When the ejected material carries away the specific angular momentum of the white dwarf, the orbital period increases. A magnetic field on the surface of the secondary star forces a fraction of the ejected material to corotate with the star, and hence the binary system. The ejected material thus takes angular momentum from the binary orbit and the orbital period decreases. We show that for sufficiently strong magnetic fields on the surface of the secondary star, the total change to the orbital period could even be negative during a nova outburst, contrary to previous expectations. Accurate determinations of pre- and post-outburst orbital periods of recurrent nova systems could test the new mechanism, in addition to providing meaningful constraints on otherwise difficult to measure physical quantities. We apply our mechanism to outbursts of the recurrent nova U Sco.

  5. High Precision Orbit Determination of CHAMP Satellite

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qile; LIU Jingnan; GE Maorong

    2006-01-01

    The precision orbit determination of challenging minisatellite payload(CHAMP) satellite was done based on position and navigation data analyst(PANDA) software which is developed in Wuhan University, using the onboard GPS data of year 2002 from day 126 to 131. The orbit accuracy was assessed by analyzing the difference from GFZ post-processed science orbits (PSO), the GPS carrier and pseudo-range data residuals and the satellite laser ranging (SLR) residuals.

  6. 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

  7. 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...

  8. Langerhans cell histiocytosis of the orbit.

    Directory of Open Access Journals (Sweden)

    Shetty S

    2001-01-01

    Full Text Available Langerhans cell histiocytosis (LCH accounts for less than 1% of all orbital tumours. Though rare, orbital involvement in LCH is not uncommon. Most reports so far have been in Western literature. We report here a case of LCH of orbit with intracranial extension. To the best of our knowledge, this is the first case of single system multifocal LCH reported from India.

  9. The Atomic orbitals of the topological atom

    OpenAIRE

    Ramos-Cordoba, Eloy; Salvador Sedano, Pedro

    2013-01-01

    The effective atomic orbitals have been realized in the framework of Bader's atoms in molecules theory for a general wavefunction. This formalism can be used to retrieve from any type of calculation a proper set of orthonormalized numerical atomic orbitals, with occupation numbers that sum up to the respective Quantum Theory of Atoms in Molecules (QTAIM) atomic populations. Experience shows that only a limited number of effective atomic orbitals exhibit significant occupation numbers. These c...

  10. 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.

  11. Semiclassical quantization with short periodic orbits

    CERN Document Server

    Vergini, E G; Vergini, Eduardo G.; Carlo, Gabriel

    2000-01-01

    We apply a recently developed semiclassical theory of short peridic orbits to the stadium billiard. We give explicit expresions for the resonances of periodic orbits and for the application of the semiclassical Hamiltonian operator to them. Then, by using the 3 shortest periodic orbits and 2 more living in the bouncing ball region, we obtain the first 25 odd-odd eigenfunctions with surprising accuracy.

  12. Orbit stability in billiards in magnetic field

    CERN Document Server

    Kovács, Z

    1997-01-01

    We study the stability properties of orbits in dispersing billiards in a homogeneous magnetic field by using a modified formalism based on the Bunimovich-Sinai curvature (horocycle method). We identify simple periodic orbits that can be stabilized by the magnetic field in the four-disk model and the square-lattice Lorentz gas. The stable orbits can play a key role in determining the transport properties of these models.

  13. 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.

  14. The Orbital Workshop Shower Compartment

    Science.gov (United States)

    1972-01-01

    This photograph shows technicians performing a checkout of the Metabolic Analyzer (center background) and the Ergometer (foreground) in the Orbital Workshop (OWS). The shower compartment is at right. The Ergometer (Skylab Experiment M171) evaluated man's metabolic effectiveness and cost of work in space environment. Located in the experiment and work area of the OWS, the shower compartment was a cylindrical cloth enclosure that was folded flat when not in use. The bottom ring of the shower was fastened to the floor and contained foot restraints. The upper ring contained the shower head and hose. To use the shower, the astronaut filled a pressurized portable bottle with heated water and attached the bottle to the ceiling. A flexible hose cornected the water bottle to a handheld shower head. The astronaut pulled the cylindrical shower wall up into position and bathed, using liquid soap. Both soap and water were carefully rationed, having been premeasured for economical use.

  15. 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.

  16. Phonons with orbital angular momentum

    Energy Technology Data Exchange (ETDEWEB)

    Ayub, M. K. [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); National Centre for Physics, Shahdra Valley Road, Quaid-i-Azam University Campus, Islamabad 44000 (Pakistan); Ali, S. [National Centre for Physics, Shahdra Valley Road, Quaid-i-Azam University Campus, Islamabad 44000 (Pakistan); Mendonca, J. T. [IPFN, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal)

    2011-10-15

    Ion accoustic waves or phonon modes are studied with orbital angular momentum (OAM) in an unmagnetized collissionless uniform plasma, whose constituents are the Boltzmann electrons and inertial ions. For this purpose, we have employed the fluid equations to obtain a paraxial equation in terms of ion density perturbations and discussed its Gaussian beam and Laguerre-Gauss (LG) beam solutions. Furthermore, an approximate solution for the electrostatic potential problem is presented, allowing to express the components of the electric field in terms of LG potential perturbations. The energy flux due to phonons is also calculated and the corresponding OAM is derived. Numerically, it is shown that the parameters such as azimuthal angle, radial and angular mode numbers, and beam waist, strongly modify the profiles of the phonon LG potential. The present results should be helpful in understanding the phonon mode excitations produced by Brillouin backscattering of laser beams in a uniform plasma.

  17. The orbital TUS detector simulation

    Science.gov (United States)

    Grinyuk, A.; Grebenyuk, V.; Khrenov, B.; Klimov, P.; Lavrova, M.; Panasyuk, M.; Sharakin, S.; Shirokov, A.; Tkachenko, A.; Tkachev, L.; Yashin, I.

    2017-04-01

    The TUS space experiment is aimed at studying energy and arrival distribution of UHECR at E > 7 × 1019 eV by using the data of EAS fluorescent radiation in atmosphere. The TUS mission was launched at the end of April 2016 on board the dedicated ;Lomonosov; satellite. The TUSSIM software package has been developed to simulate performance of the TUS detector for the Fresnel mirror optical parameters, the light concentrator of the photo detector, the front end and trigger electronics. Trigger efficiency crucially depends on the background level which varies in a wide range: from 0.2 × 106 to 15 × 106 ph/(m2 μ s sr) at moonless and full moon nights respectively. The TUSSIM algorithms are described and the expected TUS statistics is presented for 5 years of data collection from the 500 km solar-synchronized orbit with allowance for the variability of the background light intensity during the space flight.

  18. Orbital cysticercosis: A case report

    Science.gov (United States)

    Damani, Mehul; Mehta, Vinod C.; Baile, Rahul B.; Nakwa, Bhalachandra

    2012-01-01

    A 22 years old male presented to us with a history of lid swelling and chemosis of conjunctiva since 2 days. The patient had a history of convulsions 4 days back and 2 months back. The patient had undergone a CT scan which showed granulomas in temporal and parietal lobes. The patient was started on Anti tuberculosis treatment by the Physician. The Patient underwent USG B scan which revealed cysticercosis cyst in the anterior orbit inferiorly .The patient was treated with albendazole and wysolone for a month. The patient was reviewed after 1 month .The lesion resolved with the treatment both clinically and on USG. PMID:23961034

  19. 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.

  20. Spin-orbit-coupled superconductivity.

    Science.gov (United States)

    Lo, Shun-Tsung; Lin, Shih-Wei; Wang, Yi-Ting; Lin, Sheng-Di; Liang, C-T

    2014-06-25

    Superconductivity and spin-orbit (SO) interaction have been two separate emerging fields until very recently that the correlation between them seemed to be observed. However, previous experiments concerning SO coupling are performed far beyond the superconducting state and thus a direct demonstration of how SO coupling affects superconductivity remains elusive. Here we investigate the SO coupling in the critical region of superconducting transition on Al nanofilms, in which the strength of disorder and spin relaxation by SO coupling are changed by varying the film thickness. At temperatures T sufficiently above the superconducting critical temperature T(c), clear signature of SO coupling reveals itself in showing a magneto-resistivity peak. When T superconductivity. By studying such magneto-resistivity peaks under different strength of spin relaxation, we highlight the important effects of SO interaction on superconductivity.

  1. Managing resonant trapped orbits in our Galaxy

    CERN Document Server

    Binney, James

    2016-01-01

    Galaxy modelling is greatly simplified by assuming the existence of a global system of angle-action coordinates. Unfortunately, global angle-action coordinates do not exist because some orbits become trapped by resonances, especially where the radial and vertical frequencies coincide. We show that in a realistic Galactic potential such trapping occurs only on thick-disc and halo orbits (speed relative to the guiding centre >~80 km/s). We explain how the Torus Mapper code (TM) behaves in regions of phase space in which orbits are resonantly trapped, and we extend TM so trapped orbits can be manipulated as easily as untrapped ones. The impact that the resonance has on the structure of velocity space depends on the weights assigned to trapped orbits. The impact is everywhere small if each trapped orbit is assigned the phase space density equal to the time average along the orbit of the DF for untrapped orbits. The impact could be significant with a different assignment of weights to trapped orbits.

  2. Impulsive orbit control for spacecraft around asteroid

    Institute of Scientific and Technical Information of China (English)

    崔祜涛; 崔平远; 栾恩杰

    2003-01-01

    An impulse feedback control law to change the mean orbit elements of spacecraft around asteroid is presented. First, the mean orbit elements are transferred to the osculating orbit elements at the burning time.Then, the feedback control law based on Gauss' s perturbation equations of motion is given. And the impulse control for targeting from the higher circulation orbit to the specified periapsis is developed. Finally, the numerical simulation is performed and the simulation results show that the presented impulse control law is effective.

  3. 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˜$X/\\widetildeG$

  4. Primary orbital neuroblastoma in a neonate

    Directory of Open Access Journals (Sweden)

    Mirzai Hasan

    2006-01-01

    Full Text Available Neuroblastoma is an undifferentiated malignant tumor of the primitive neuroblasts. Orbital neuroblastoma is typically a metastatic tumor. We describe a two-days-old girl, who presented with a large tumor in her left orbit. Magnetic resonance imaging revealed that the tumor originated from the retrobulbar area, extending into the upper and lateral orbit. She was operated on the fifth day of life. A histopathologic diagnosis of neuroblastoma was made. Medical evaluation including chest roentgenogram, ultrasonography of the abdomen, whole body computerized tomogram and bone scintigraphy showed no evidence of systemic involvement or metastasis. Neuroblastoma should be considered in the differential diagnosis of neonatal orbital tumors.

  5. Sun-synchronous satellite orbit determination

    Science.gov (United States)

    Ma, Der-Ming; Zhai, Shen-You

    2004-02-01

    The linearized dynamic equations used for on-board orbit determination of Sun-synchronous satellite are derived. Sun-synchronous orbits are orbits with the secular rate of the right ascension of the ascending node equal to the right ascension rate of the mean sun. Therefore the orbit is no more a closed circle but a tight helix about the Earth. In the paper, instead of treating the orbit as a closed circle, the actual helix orbit is taken as nominal trajectory. The details of the linearized equations of motion for the satellite in the Sun-synchronous orbit are derived. The linearized equations are obtained by perturbing the Keplerian motion with the J2 correction and the effect of sun's attraction being neglected. Combined with the GPS navigation equations, the Kalman filter formulation is given. The particular application considered is the circular Sun-synchronous orbit with the altitude of 800 km and inclination of 98.6°. The numerical example simulated by MATLAB® shows that only the pseudo-range data used in the algorithm still gives acceptable results. Based on the simulation results, we can use the on-board GPS receivers' signal only as an alternative to determine the orbit of Sun-Synchronous satellite and therefore circumvents the need for extensive ground support.

  6. Frontal mucocele with an accompanying orbital abscess mimicking a fronto-orbital mucocele: case report

    Directory of Open Access Journals (Sweden)

    Akkuzu Guzin

    2006-04-01

    Full Text Available Abstract Background Mucoceles are slowly expanding cystic lesions with respiratory epithelium containing mucus most commonly affecting the frontal and ethmoidal sinuses. They are caused by obstruction of sinus ostium. Mucoceles exert pressure on the bony boundaries and due to the proximity to the brain and orbit extension to these areas are common. Case presentation A case of a frontal mucocele with an accompanying orbital abscess mimicking a fronto-orbital mucocele is reported. A 77 year old female patient suffering from left sided proptosis and pain around the left eye was admitted to our department. She had a history of left frontal sinus mucocele one year ago that was offered an osteoplastic frontal sinus surgery that the patient refused. Patient had limitation of eye movements. Fundoscopic examination revealed a minimal papilledema. Coronal computerized tomography and orbital magnetic resonance imaging showed a frontal mucocele with suspicious erosion of the orbital roof and a superiorly localized extraconal mass displacing the orbit lateroinferiorly. Frontal and orbital masses had similar intensities. Thus surgery was planned for a fronto-orbital mucocele. During surgery no defect was found on the orbital roof. Frontal mucocele and orbital cystic mass was removed separately. Pathological examination showed a frontal mucocele and an orbital abscess wall. Postoperatively eye movements returned to normal and papilledema resolved. Conclusion Fronto-orbital mucoceles are commonly encountered pathologies, but frontal mucocele with an orbital abscess is a rarely seen and should be kept in mind because their treatments differ.

  7. Trimer effects in fragment molecular orbital-linear combination of molecular orbitals calculation of one-electron orbitals for biomolecules.

    Science.gov (United States)

    Kobori, Tomoki; Sodeyama, Keitaro; Otsuka, Takao; Tateyama, Yoshitaka; Tsuneyuki, Shinji

    2013-09-07

    The fragment molecular orbital (FMO)-linear combination of molecular orbitals (LCMO) method incorporates as an efficient post-process calculation of one-electron orbitals of the whole system after the FMO total energy calculation. A straightforward way to increase the accuracy is inclusion of the trimer effect. Here, we derive a comprehensive formulation called the FMO3-LCMO method. To keep the computational costs of the trimer term low enough, we use a matrix-size reduction technique. We evaluated the accuracy and efficiency of the FMO3-LCMO scheme in model biological systems (alanine oligomer and chignolin). The results show that delocalized electronic orbitals with covalent and hydrogen bonds are better described at the trimer level, and the FMO3-LCMO method is applicable to quantitative evaluations of a wide range of frontier orbitals in large biosystems.

  8. Small Orbital Stereo Tracking Camera Technology Development

    Science.gov (United States)

    Bryan, Tom; MacLeod, Todd; Gagliano, Larry

    2016-01-01

    On-Orbit Small Debris Tracking and Characterization is a technical gap in the current National Space Situational Awareness necessary to safeguard orbital assets and crew. This poses a major risk of MOD damage to ISS and Exploration vehicles. In 2015 this technology was added to NASA's Office of Chief Technologist roadmap. For missions flying in or assembled in or staging from LEO, the physical threat to vehicle and crew is needed in order to properly design the proper level of MOD impact shielding and proper mission design restrictions. Need to verify debris flux and size population versus ground RADAR tracking. Use of ISS for In-Situ Orbital Debris Tracking development provides attitude, power, data and orbital access without a dedicated spacecraft or restricted operations on-board a host vehicle as a secondary payload. Sensor Applicable to in-situ measuring orbital debris in flux and population in other orbits or on other vehicles. Could enhance safety on and around ISS. Some technologies extensible to monitoring of extraterrestrial debris as well To help accomplish this, new technologies must be developed quickly. The Small Orbital Stereo Tracking Camera is one such up and coming technology. It consists of flying a pair of intensified megapixel telephoto cameras to evaluate Orbital Debris (OD) monitoring in proximity of International Space Station. It will demonstrate on-orbit optical tracking (in situ) of various sized objects versus ground RADAR tracking and small OD models. The cameras are based on Flight Proven Advanced Video Guidance Sensor pixel to spot algorithms (Orbital Express) and military targeting cameras. And by using twin cameras we can provide Stereo images for ranging & mission redundancy. When pointed into the orbital velocity vector (RAM), objects approaching or near the stereo camera set can be differentiated from the stars moving upward in background.

  9. A strange attractor in the unfolding of an orbit-flip homoclinic orbit

    NARCIS (Netherlands)

    Naudot, [No Value

    2002-01-01

    An orbit-flip homoclinic orbit Gamma of a vector field defined on R-3 is a homoclinic orbit to an equilibrium point for which the one-dimensional unstable manifold of the equilibrium point is connected to the one-dimensional strong stable manifold. In this paper, we show that in a generic unfolding

  10. Predictability in orbital reconstruction: a human cadaver study: part I: endoscopic-assisted orbital reconstruction

    NARCIS (Netherlands)

    Dubois, L.; Jansen, J.; Schreurs, R.; Saeed, P.; Beenen, L.; Maal, T.J.J.; Gooris, P.J.J.; Becking, A.G.

    2015-01-01

    In the treatment of orbital defects, surgeon errors may lead to incorrect positioning of orbital implants and, consequently, poor clinical outcomes. Endoscopy can provide additional visualization of the orbit through the transantral approach. We aimed to evaluate whether endoscopic guidance during o

  11. Predictability in orbital reconstruction: A human cadaver study. Part II: Navigation-assisted orbital reconstruction

    NARCIS (Netherlands)

    Dubois, L.; Schreurs, R.; Jansen, J; Maal, T.J.J.; Essig, H.; Gooris, P.J.; Becking, A.G.

    2015-01-01

    Preformed orbital reconstruction plates are useful for treating orbital defects. However, intraoperative errors can lead to misplaced implants and poor outcomes. Navigation-assisted surgery may help optimize orbital reconstruction. We aimed to explore whether navigation-assisted surgery is more pred

  12. Predictability in orbital reconstruction: A human cadaver study. Part I: Endoscopic-assisted orbital reconstruction

    NARCIS (Netherlands)

    Dubois, L.; Jansen, J; Schreurs, R.; Saeed, P.; Beenen, L.; Maal, T.J.J.; Gooris, P.J.; Becking, A.G.

    2015-01-01

    In the treatment of orbital defects, surgeon errors may lead to incorrect positioning of orbital implants and, consequently, poor clinical outcomes. Endoscopy can provide additional visualization of the orbit through the transantral approach. We aimed to evaluate whether endoscopic guidance during o

  13. Predictability in orbital reconstruction: a human cadaver study: part II: navigation-assisted orbital reconstruction

    NARCIS (Netherlands)

    Dubois, L.; Schreurs, R.; Jansen, J.; Maal, T.J.J.; Essig, H.; Gooris, P.J.J.; Becking, A.G.

    2015-01-01

    Preformed orbital reconstruction plates are useful for treating orbital defects. However, intraoperative errors can lead to misplaced implants and poor outcomes. Navigation-assisted surgery may help optimize orbital reconstruction. We aimed to explore whether navigation-assisted surgery is more pred

  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 pseudotumor imaged with Ga-67 citrate

    Energy Technology Data Exchange (ETDEWEB)

    Jaikishen, P.; Bateman, J.L.; Shreeve, W.W. (Veterans Administration Medical Center, Northport, NY (USA))

    1989-11-01

    An orbital pseudotumor causing proptosis, diplopia, and gaze palsy was imaged with Ga-67 citrate and showed persistent intense activity for five days. This may be the first case of gallium uptake into an orbital pseudotumor to be reported in the literature. This case report demonstrates the use of Ga-67 citrate imaging in the early diagnostic workup of this disorder.

  16. The Homoclinic Orbits in Nonlinear Schroedinger Equation

    Institute of Scientific and Technical Information of China (English)

    PengchengXU; BolingGUO; 等

    1998-01-01

    The persistence of Homoclinic orbits for perturbed nonlinear Schroedinger equation with five degree term under een periodic boundary conditions is considered.The exstences of the homoclinic orbits for the truncation equation is established by Melnikov's analysis and geometric singular perturbation theory.

  17. 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.

  18. Extraskeletal myxoid chondrosarcoma of the orbit

    Directory of Open Access Journals (Sweden)

    Abdullah M Al-Osaily

    2016-01-01

    Full Text Available 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.

  19. Orbital dissection defatting technique for Graves disease.

    Science.gov (United States)

    Hecht, S D; Guibor, P; Wolfley, D; Wiggs, E O

    1984-04-01

    Five patients with Graves disease and bilateral proptosis were treated with different incisional approaches. They all underwent orbital decompression by removal of the anterior medial orbital walls, the anterior ethmoidal sinuses, the orbital floors, and multiple incisions of the orbital periosteums . The defatting technique, which consists of applying manual anterior orbital pressure with alternate removing of small lobules of fat, was added when it was intraoperatively decided by Hertel exophthalmometer measurement that more decompression was needed. It is estimated that one-third more reduction in proptosis resulted. An average total decrease in proptosis of 9 mm per orbit occurred. Both visual accuities and visual fields returned to normal. The only important complication was the development of hypertropia in down gaze in one patient. A potential value of this technique is its use with orbital floor decompression alone. It may be possible to avoid removing the medial and lateral walls of the orbit, thereby decreasing complications. Defatting may also be a valuable addition in those rare cases where all decompression techniques available are needed to affect an adequate decompression.

  20. 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.

  1. 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.

  2. 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 part

  3. Spin-Orbit induced semiconductor spin guides

    OpenAIRE

    Valin-Rodriguez, Manuel; Puente, Antonio; Serra, Llorens

    2002-01-01

    The tunability of the Rashba spin-orbit coupling allows to build semiconductor heterostructures with space modulated coupling intensities. We show that a wire-shaped spin-orbit modulation in a quantum well can support propagating electronic states inside the wire only for a certain spin orientation and, therefore, it acts as an effective spin transmission guide for this particular spin orientation.

  4. Three Temperate Neptunes Orbiting Nearby Stars

    CERN Document Server

    Fulton, Benjamin J; Weiss, Lauren M; Sinukoff, Evan; Petigura, Erik A; Isaacson, Howard; Hirsch, Lea; Marcy, Geoffrey W; Henry, Gregory W; Grunblatt, Samuel K; Huber, Daniel; von Braun, Kaspar; Boyajian, Tabetha S; Kane, Stephen R; Wittrock, Justin; Horch, Elliott P; Ciardi, David R; Howell, Steve B; Wright, Jason T; Ford, Eric B

    2016-01-01

    We present the discovery of three modestly-irradiated, roughly Neptune-mass planets orbiting three nearby Solar-type stars. HD 42618 b has a minimum mass of $15.4 \\pm 2.4$ M$_{\\oplus}$, a semi-major axis of 0.55 AU, an equilibrium temperature of 337 K, and is the first planet discovered to orbit the solar analogue host star, HD 42618. We also discover new planets orbiting the known exoplanet host stars HD 164922 and HD 143761 ($\\rho$ CrB). The new planet orbiting HD 164922 has a minimum mass of $12.9 \\pm 1.6$ M$_{\\oplus}$ and orbits interior to the previously known Jovian mass planet orbiting at 2.1 AU. HD 164922 c has a semi-major axis of 0.34 AU and an equilibrium temperature of 418 K. HD 143761 c orbits with a semi-major axis of 0.44 AU, has a minimum mass of $25 \\pm 2$ M$_{\\oplus}$, and is the warmest of the three new planets with an equilibrium temperature of 445 K. It orbits exterior to the previously known warm Jupiter in the system. A transit search using space-based CoRoT data and ground-based photom...

  5. Orbital infarction in sickle cell disease.

    Science.gov (United States)

    Blank, J P; Gill, F M

    1981-06-01

    Bone infarction is a common occurrence in sickle cell disease. Described are three cases in which frontal headache, proptosis, and lid edema were seen with infarction of the orbital bone. Radionuclide scanning was useful in distinguished bone infarction from orbital infection in one case.

  6. On-Orbit Propulsion OMS/RCS

    Science.gov (United States)

    Hurlbert, Eric A.

    2001-01-01

    This slide presentation reviews the Space Shuttle's On-Orbit Propulsion systems: the Orbital Maneuvering System (OMS) and the Reaction Control System (RCS). The functions of each of the systems is described, and the diagrams of the systems are presented. The OMS/RCS thruster is detailed and a trade study comparison of non-toxic propellants is presented.

  7. The Orbits of Saturn's Small Satellites

    Science.gov (United States)

    Spitale, J. N.; Jacobson, R. A.; Porco, C. C.; Owen, W. M.; Charnoz, S.

    2005-05-01

    We report on the orbits of the small, inner Saturnian satellites, either recovered or newly-discovered in recent Cassini imaging observations (excluding Helene, Telesto and Calypso, which will be discussed by another group). Using combined Cassini and Voyager observations, the mean motions of Pan and Atlas have been refined by several orders of magnitude. The Atlas orbit is based on a numerical integration perturbed by all of the massive Saturnian satellites including Prometheus, Pandora, Janus, and Epimetheus. We find that the dominant perturber is Prometheus. Cassini, Voyager, HST, and Earth-based data have been used to refine the orbits of Janus, Epimetheus, Prometheus and Pandora. The orbits of the co-orbitals, Janus and Epimetheus, remain stable; their orbital swap does not occur until Februrary, 2006. The orbits of Prometheus and Pandora remain close to recent values (Jacobson and French 2004, Icarus, 172, 382). Six new objects have been discovered to date -- three (S/2004 S3, S4, S6) in close proximity to the F ring, two (S/2004 S1(Methone), S/2004 S2(Pallene)) between the orbits of Mimas and Enceladus, and one (S/2004 S5(Polydeuces)) co-orbital with Dione, trailing by ˜60 deg (Porco et al., Science 307, 25 Feb 2005). One of the F-ring objects -- S/2004 S3 -- was seen over a 118-day interval, but none of those objects, including S/2004 S3, were subsequently recovered in an F-ring movie acquired on 15 November 2004 (29 days after the last sighting of S/2004 S3) with an image scale of 4 km/pixel, in which all were expected to appear. Consequently, we are confident only that Methone, Pallene and Polydeuces are solid satellites; S/2004 S3, S4 and S6 may be transient clumps. Our orbital fits, both precessing ellipse models and orbital integrations, suggest that Pallene is the same object as S/1981 S14, imaged by Voyager 2 on 23 August 1981, contrary to our initial reports (IAU circular 8389). The orbital inclination and eccentricity of Methone are considerably

  8. Automated Selection of Active Orbital Spaces

    CERN Document Server

    Stein, Christopher J

    2016-01-01

    One of the key challenges of quantum-chemical multi-configuration methods is the necessity to manually select orbitals for the active space. This selection requires both expertise and experience and can therefore impose severe limitations on the applicability of this most general class of ab initio methods. A poor choice of the active orbital space may yield even qualitatively wrong results. This is obviously a severe problem, especially for wave function methods that are designed to be systematically improvable. Here, we show how the iterative nature of the density matrix renormalization group combined with its capability to include up to about one hundred orbitals in the active space can be exploited for a systematic assessment and selection of active orbitals. These benefits allow us to implement an automated approach for active orbital space selection, which can turn multi-configuration models into black box approaches.

  9. 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.

  10. Orbital Motion During Gravitational Lensing Events

    CERN Document Server

    Di Stefano, Rosanne

    2014-01-01

    Gravitational lensing events provide unique opportunities to discover and study planetary systems and binaries. Here we build on previous work to explore the role that orbital motion can play in both identifying and learning more about multiple-mass systems that serve as gravitational lenses. We find that a significant fraction of planet-lens and binary-lens light curves are influenced by orbital motion. Furthermore, the effects of orbital motion extend the range of binaries for which lens multiplicity can be discovered and studied. Orbital motion will play an increasingly important role as observations with sensitive photometry, such as those made by the space missions Kepler, Transiting Exoplanet Survey Satellite, (TESS), and WFIRST discover gravitational lensing events. Similarly, the excellent astrometric measurements made possible by GAIA will allow it to study the effects of orbital motion. Frequent observations, such as those made possible with the Korean Microlensing Telescope Network, KMTNet, will al...

  11. Orbital dystopia managed with unilateral brow suspension.

    Science.gov (United States)

    Taub, Peter J; Koch, R Michael

    2006-11-01

    Patients with orbital dystopia present with symptoms of diplopia and/or facial asymmetry. Repositioning of the orbit requires multiple osteotomies around the orbit, which presents significant complications. The authors present an alternative method to restore facial symmetry in the case of a 14-year-old patient with congenital orbital dystopia due to fibrosis of the sternocleidomastoid muscle. The patient had no ocular symptoms but did have asymmetric descent of the ipsilateral brow. He refused box osteotomy and repositioning of the orbit. Unilateral brow suspension was performed using an endoscopic technique and suspension sutures fixed to resorbable screws. Adequate brow elevation was noted in the immediate postoperative period and at 6 months; it successfully restored facial symmetry.

  12. Molecular orbital imaging for partially aligned molecules

    Science.gov (United States)

    Qin, Meiyan; Zhu, Xiaosong

    2017-01-01

    We investigate molecular orbital reconstruction using high-order harmonic emissions from partially aligned molecular ensembles. By carrying out the reconstruction procedure using the harmonic sampling with or without the spectral minimum, the roles of the harmonic phase and amplitude modulation due to the partial alignment can be separately studied. It is found that with the prior knowledge of the orbital symmetry, the reconstructed result is very sensitive to the modulation of the harmonic phase for the πg orbital, while in the case of σg orbital, the reconstructed result is mainly determined by the harmonic amplitude. These results can provide an important reference for the future experiment of molecular orbital imaging.

  13. 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....

  14. Primary orbital neuroblastoma with intraocular extension

    Directory of Open Access Journals (Sweden)

    Muthukrishnan Vallinayagam

    2015-01-01

    Full Text Available Neuroblastoma is an undifferentiated malignancy of primitive neuroblasts. Neuroblastoma is among the most common solid tumors of childhood. Orbital neuroblastoma is typically a metastatic tumor. In this case report, we describe a 2-year-old child with a rapidly progressing orbital tumor. Computed tomography revealed an orbital mass lesion with extraocular and intraocular components. An incisional biopsy was done, and a histopathological examination showed features suggestive of neuroblastoma. Systemic workup including ultrasonography of the abdomen, chest roentgenogram, whole body computed tomography, and bone scintigraphy showed no evidence of systemic involvement. The diagnosis of primary orbital neuroblastoma was made, and the child was subjected to chemotherapy followed by rapid melting of the tumor. Neuroblastoma should be considered in the differential diagnosis of childhood orbital tumors.

  15. Spin-orbit interactions between two baryons

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Sachiko [Japan College of Social Work, Kiyose, Tokyo (Japan); Morimatsu, Osamu [High Energy Accelerator Research Organization, Tanashi Branch (KEK-Tanashi), Tanashi, Tokyo (Japan); Tani, Yoshihiro; Oka, Makoto [Tokyo Inst. of Tech. (Japan). Dept. of Physics

    2000-04-01

    The spin-orbit interactions in the quark cluster models are reviewed in this article. The observed spin-orbit force between two nucleons is strong, while that in the excited baryons or in the {lambda}N interaction is small. We try to sort out whether the quark cluster model can produce a spin-orbit force which explains these features simultaneously. Various works which include the spin-orbit force with different origins such as gluons, mesons, or coupling to other channels are compared to each other. The roles of the symmetric and anti-symmetric spin- orbit forces in the NN scattering phase shifts and in the YN low-energy cross sections and the phase shifts are investigated. (author)

  16. 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.

  17. The statistical mechanics of planet orbits

    CERN Document Server

    Tremaine, Scott

    2015-01-01

    The final "giant-impact" phase of terrestrial planet formation is believed to begin with a large number of planetary "embryos" on nearly circular, coplanar orbits. Mutual gravitational interactions gradually excite their eccentricities until their orbits cross and they collide and merge; through this process the number of surviving bodies declines until the system contains a small number of planets on well-separated, stable orbits. In this paper we explore a simple statistical model for the orbit distribution of planets formed by this process, based on the sheared-sheet approximation and the ansatz that the planets explore uniformly all of the stable region of phase space. The model provides analytic predictions for the distribution of eccentricities and semimajor axis differences, correlations between orbital elements of nearby planets, and the complete N-planet distribution function, in terms of a single parameter that is determined by the planetary masses. The predicted properties are generally consistent ...

  18. 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.

  19. Spacewire on Earth orbiting scatterometers

    Science.gov (United States)

    Bachmann, Alex; Lang, Minh; Lux, James; Steffke, Richard

    2002-01-01

    The need for a high speed, reliable and easy to implement communication link has led to the development of a space flight oriented version of IEEE 1355 called SpaceWire. SpaceWire is based on high-speed (200 Mbps) serial point-to-point links using Low Voltage Differential Signaling (LVDS). SpaceWIre has provisions for routing messages between a large network of processors, using wormhole routing for low overhead and latency. {additionally, there are available space qualified hybrids, which provide the Link layer to the user's bus}. A test bed of multiple digital signal processor breadboards, demonstrating the ability to meet signal processing requirements for an orbiting scatterometer has been implemented using three Astrium MCM-DSPs, each breadboard consists of a Multi Chip Module (MCM) that combines a space qualified Digital Signal Processor and peripherals, including IEEE-1355 links. With the addition of appropriate physical layer interfaces and software on the DSP, the SpaceWire link is used to communicate between processors on the test bed, e.g. sending timing references, commands, status, and science data among the processors. Results are presented on development issues surrounding the use of SpaceWire in this environment, from physical layer implementation (cables, connectors, LVDS drivers) to diagnostic tools, driver firmware, and development methodology. The tools, methods, and hardware, software challenges and preliminary performance are investigated and discussed.

  20. Neutron Skins and Halo Orbits

    CERN Document Server

    Bonnard, J; Zuker, A P

    2016-01-01

    The strong dependence of Coulomb energies on nuclear radii makes it possible to extract the latter from calculations of the former. The resulting estimates of neutron skins indicate that two mechanisms are involved. The first one---isovector monopole polarizability---amounts to noting that when a particle is added to a system it drives the radii of neutrons and protons in different directions, tending to equalize the radii of both fluids independently of the neutron excess. This mechanism is well understood and the Duflo-Zuker (small) neutron skin values derived 14 years ago are consistent with recent measures and estimates. The alternative mechanism involves halo orbits whose huge sizes tend to make the neutron skins larger and have a subtle influence on the radial behavior of $sd$ and $pf$ shell nuclei. In particular, they account for the sudden rise in the isotope shifts of nuclei beyond $N=28$ and the near constancy of radii in the $A=40-56$ region. This mechanism, detected here for the first time, is not...

  1. Orbital Debris Observations with WFCAM

    Science.gov (United States)

    Bold, Matthew; Cross, Nick; Irwin, Mike; Kendrick, Richard; Kerr, Thomas; Lederer, Susan; Mann, Robert; Sutorius, Eckhard

    2014-01-01

    The United Kingdom Infrared Telescope has been operating for 35 years on the summit of Mauna Kea as a premier Infrared astronomical facility. In its 35th year the telescope has been turned over to a new operating group consisting of University of Arizona, University of Hawaii and the LM Advanced Technology Center. UKIRT will continue its astronomical mission with a portion of observing time dedicated to orbital debris and Near Earth Object detection and characterization. During the past 10 years the UKIRT Wide Field CAMera (WFCAM) has been performing large area astronomical surveys in the J, H and K bands. The data for these surveys have been reduced by the Cambridge Astronomical Survey Unit in Cambridge, England and archived by the Wide Field Astronomy Unit in Edinburgh, Scotland. During January and February of 2014 the Wide Field CAMera (WFCAM) was used to scan through the geostationary satellite belt detecting operational satellites as well as nearby debris. Accurate photometric and astrometric parameters have been developed by CASU for each of the detections and all data has been archived by WFAU.

  2. 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.

  3. Study of orbit stability in the SSRF storage ring

    Institute of Scientific and Technical Information of China (English)

    DAI Zhi-Min; LIU Gui-Min; HUANG Nan

    2003-01-01

    In this paper, analysis of the beam orbit stability and conceptual study of the dynamic orbit feedback inthe SSRF storage ring are presented. It is shown that beam orbit position movement at the photon source points issmaller than the orbit stability requirements in horizontal plane, but exceeds the orbit stability requirements in verticalplane. A dynamic global orbit feedback system, which consists of 38 high-bandwidth air-coil correctors and 40high-precise BPMs, is proposed to suppress the vertical beam orbit position movement. Numerical simulations showthat this dynamic orbit feedback system can stabilize the vertical beam orbit position movement in the frequencyrange up to 100 Hz.

  4. 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.

  5. Projected seniority-two orbital optimization of the antisymmetric product of one-reference orbital geminal

    Science.gov (United States)

    Boguslawski, Katharina; Tecmer, Paweł; Limacher, Peter A.; Johnson, Paul A.; Ayers, Paul W.; Bultinck, Patrick; De Baerdemacker, Stijn; Van Neck, Dimitri

    2014-06-01

    We present a new, non-variational orbital-optimization scheme for the antisymmetric product of one-reference orbital geminal wave function. Our approach is motivated by the observation that an orbital-optimized seniority-zero configuration interaction (CI) expansion yields similar results to an orbital-optimized seniority-zero-plus-two CI expansion [L. Bytautas, T. M. Henderson, C. A. Jimenez-Hoyos, J. K. Ellis, and G. E. Scuseria, J. Chem. Phys. 135, 044119 (2011)]. A numerical analysis is performed for the C2 and LiF molecules, for the CH2 singlet diradical as well as for the symmetric stretching of hypothetical (linear) hydrogen chains. For these test cases, the proposed orbital-optimization protocol yields similar results to its variational orbital optimization counterpart, but prevents symmetry-breaking of molecular orbitals in most cases.

  6. Orbital Complications of Sinusitis A Review

    Directory of Open Access Journals (Sweden)

    Balasubramanian Thiagarajan

    2014-08-01

    Full Text Available Abstract: Introduction: Despite availability of excellent antibiotics, orbital complications’ following sinusitis is rather common. With the emergence of fungal sinusitis orbital involvement by the disease is getting frequent. Prevalence of life style disorders like diabetes mellitus has added to the woes. This article attempts to review the entire gamut of orbital complications following sinus infections. Aim: This study aims at analyzing orbital complications following sinusitis at Government Stanley Medical College Hospital during the period 2009 – 2013. Study design: Retrospective study Methodology: Cases with rhinosinusitis treated in our Institution during the period 2009-2013 were taken up for analysis. 112 patients were chosen for the study. Their case records were analyzed. CT scan images taken during the time of admission were also evaluated. Patients with orbitalcomplications following rhinosinusitis were included. Chandler’s classification was used to categorize the stage of disease. Results: 112 patients were included in the study. 76 Male patients 36 Female patients 26 patients developed orbital complications Number of male patients with orbital complication – 22 Number of female patients with orbital complication – 4 Number of patients who died due to complications - 2 Conclusion: High degree of suspicion, early diagnosis and aggressive medical management of Chandler’s categories I and II will go a long way in preventing irreparable damage to vision. All our patients were managed initially with parenteral antibiotics. Patients who do not show improvement even after 4 days of antibiotic therapy were taken up for surgical management.

  7. The atomic orbitals of the topological atom.

    Science.gov (United States)

    Ramos-Cordoba, Eloy; Salvador, Pedro; Mayer, István

    2013-06-07

    The effective atomic orbitals have been realized in the framework of Bader's atoms in molecules theory for a general wavefunction. This formalism can be used to retrieve from any type of calculation a proper set of orthonormalized numerical atomic orbitals, with occupation numbers that sum up to the respective Quantum Theory of Atoms in Molecules (QTAIM) atomic populations. Experience shows that only a limited number of effective atomic orbitals exhibit significant occupation numbers. These correspond to atomic hybrids that closely resemble the core and valence shells of the atom. The occupation numbers of the remaining effective orbitals are almost negligible, except for atoms with hypervalent character. In addition, the molecular orbitals of a calculation can be exactly expressed as a linear combination of this orthonormalized set of numerical atomic orbitals, and the Mulliken population analysis carried out on this basis set exactly reproduces the original QTAIM atomic populations of the atoms. Approximate expansion of the molecular orbitals over a much reduced set of orthogonal atomic basis functions can also be accomplished to a very good accuracy with a singular value decomposition procedure.

  8. 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.

  9. THE STATISTICAL MECHANICS OF PLANET ORBITS

    Energy Technology Data Exchange (ETDEWEB)

    Tremaine, Scott, E-mail: tremaine@ias.edu [Institute for Advanced Study, Princeton, NJ 08540 (United States)

    2015-07-10

    The final “giant-impact” phase of terrestrial planet formation is believed to begin with a large number of planetary “embryos” on nearly circular, coplanar orbits. Mutual gravitational interactions gradually excite their eccentricities until their orbits cross and they collide and merge; through this process the number of surviving bodies declines until the system contains a small number of planets on well-separated, stable orbits. In this paper we explore a simple statistical model for the orbit distribution of planets formed by this process, based on the sheared-sheet approximation and the ansatz that the planets explore uniformly all of the stable region of phase space. The model provides analytic predictions for the distribution of eccentricities and semimajor axis differences, correlations between orbital elements of nearby planets, and the complete N-planet distribution function, in terms of a single parameter, the “dynamical temperature,” that is determined by the planetary masses. The predicted properties are generally consistent with N-body simulations of the giant-impact phase and with the distribution of semimajor axis differences in the Kepler catalog of extrasolar planets. A similar model may apply to the orbits of giant planets if these orbits are determined mainly by dynamical evolution after the planets have formed and the gas disk has disappeared.

  10. Orbital optical lattices with bosons

    Science.gov (United States)

    Kock, T.; Hippler, C.; Ewerbeck, A.; Hemmerich, A.

    2016-02-01

    This article provides a synopsis of our recent experimental work exploring Bose-Einstein condensation in metastable higher Bloch bands of optical lattices. Bipartite lattice geometries have allowed us to implement appropriate band structures, which meet three basic requirements: the existence of metastable excited states sufficiently protected from collisional band relaxation, a mechanism to excite the atoms initially prepared in the lowest band with moderate entropy increase, and the possibility of cross-dimensional tunneling dynamics, necessary to establish coherence along all lattice axes. A variety of bands can be selectively populated and a subsequent thermalization process leads to the formation of a condensate in the lowest energy state of the chosen band. As examples the 2nd, 4th and 7th bands in a bipartite square lattice are discussed. The geometry of the 2nd and 7th bands can be tuned such that two inequivalent energetically degenerate energy minima arise at the X ±-points at the edge of the 1st Brillouin zone. In this case even a small interaction energy is sufficient to lock the phase between the two condensation points such that a complex-valued chiral superfluid order parameter can emerge, which breaks time reversal symmetry. In the 4th band a condensate can be formed at the Γ-point in the center of the 1st Brillouin zone, which can be used to explore topologically protected band touching points. The new techniques to access orbital degrees of freedom in higher bands greatly extend the class of many-body scenarios that can be explored with bosons in optical lattices.

  11. The Broucke-H\\'enon orbit and the Schubart Orbit in the planar three-body problem with equal masses

    OpenAIRE

    Kuang, Wentian; Ouyang, Tiancheng; Xie, Zhifu; Yan, Duokui

    2016-01-01

    In this paper, we apply variational method to study the variational properties of two special orbits: the Schubart orbit and the Broucke-H\\'enon orbit. We show that under an appropriate boundary setting, the action minimizer must be either the Schubart orbit or the Broucke-H\\'enon orbit.

  12. Autogenous orbital reconstruction in a child with congenital abnormalities of the orbital roof and vertical orbital dystopia.

    Science.gov (United States)

    Moore, Forrest O; Thornton, Brian P; Zabel, David D; Vasconez, Henry C

    2004-11-01

    Congenital anomalies of the orbital roof are rare occurrences. The case of a 2-year-old child with vertical orbital dystopia and abnormalities of the right bony orbit is presented. The patient underwent right orbital reconstruction to restore facial symmetry. A coronal approach with a frontal craniotomy was used for intracranial exposure. The abnormal angulation of the roof was corrected, and the defect was reconstructed with a split-calvarial bone graft harvested from the parietal region. The bone graft was secured with resorbable plate fixation. To preserve vision, reconstruction of this type must be done at an early age, preferably before the age of 4 years. In this patient, there is good facial symmetry and normal globe positioning 5 years after surgery.

  13. Diffusive chaos in navigation satellites orbits

    CERN Document Server

    Daquin, J; Tsiganis, K

    2016-01-01

    The navigation satellite constellations in medium-Earth orbit exist in a background of third-body secular resonances stemming from the perturbing gravitational effects of the Moon and the Sun. The resulting chaotic motions, emanating from the overlapping of neighboring resonant harmonics, induce especially strong perturbations on the orbital eccentricity, which can be transported to large values, thereby increasing the collision risk to the constellations and possibly leading to a proliferation of space debris. We show here that this transport is of a diffusive nature and we present representative diffusion maps that are useful in obtaining a global comprehension of the dynamical structure of the navigation satellite orbits.

  14. The orbital mechanics of flight mechanics

    Science.gov (United States)

    Dunning, R. S.

    1973-01-01

    A reference handbook on modern dynamic orbit theory is presented. Starting from the most basic inverse-square law, the law of gravity for a sphere is developed, and the motion of point masses under the influence of a sphere is considered. The reentry theory and the orbital theory are discussed along with the relative motion between two bodies in orbit about the same planet. Relative-motion equations, rectangular coordinates, and the mechanics of simple rigid bodies under the influence of a gravity gradient field are also discussed.

  15. From one Reeb orbit to two

    CERN Document Server

    Cristofaro-Gardiner, Daniel

    2012-01-01

    We show that every (possibly degenerate) contact form on the three-sphere giving the tight contact structure has at least two embedded Reeb orbits. The same holds for any closed contact three-manifold satisfying a weak version of the "Volume Conjecture" in embedded contact homology. The Volume Conjecture itself, which is expected to hold for every closed contact three-manifold, implies that either there are at least three embedded Reeb orbits, or there are two embedded Reeb orbits with an explicit upper bound on the product of their symplectic actions.

  16. 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.

  17. Recolliding orbits in an intense laser field

    CERN Document Server

    Kamor, Adam; Chandre, Cristel; UZer, Turgay

    2013-01-01

    We show that a family of key periodic orbits drive the recollision process in a strong circulary polarized laser field. These orbits, coined recolliding periodic orbits, exist for a wide range of parameters and their relative influence changes as the laser and atomic parameters are varied. We find the necessary conditions for recollision-driven nonsequential double ionization to occur. The outlined mechanism is universal in that it applies equally well beyond atoms: The internal structure of the target species plays a minor role in the recollision process.

  18. Disseminated orbital actinomycetoma: A case report

    Directory of Open Access Journals (Sweden)

    Shanbhag Nita

    2010-01-01

    Full Text Available Mycetoma is a chronic granulomatous infection. Lower extremities are commonly involved. A 20-year-old male came with complaints of multiple sinuses on scalp, left eyelid swelling with a sinus and dystopia, since one year. On examination there was relative proptosis in left eye of 2 mm. Computed tomography scan showed soft tissue swelling of the pre-septal area of the left upper eyelid with orbital involvement. Magnetic resonance imaging showed increased left orbital volume and evident dystopia. Microbiology testing of the erosive scalp and lid lesions showed genus Nocardia, suggestive of actinomycetoma. This case is presented as it shows an unusual involvement of the orbit.

  19. The INTEGRAL spacecraft - in-orbit performance

    Science.gov (United States)

    Jensen, P. L.; Clausen, K.; Cassi, C.; Ravera, F.; Janin, G.; Winkler, C.; Much, R.

    2003-11-01

    The INTEGRAL satellite was successfully launched from Baikonur on 17 October, 2002. INTEGRAL is an observatory for gamma-ray astronomy. The goals are to provide unprecedented high resolution imaging capability for unambiguous identification of gamma ray sources and high energy resolution for line spectroscopy. This paper summarises the actual orbital evolution based on the first 8 months in orbit and provides a status of the on-board limiting life resources. The paper describes the measured in-orbit performance of the INTEGRAL satellite and summarizes the applicable operational constraints for the science user community.

  20. Ultrasonography of the eye and orbit.

    Science.gov (United States)

    Dudea, Sorin M

    2011-06-01

    Ultrasonography (US) is, quite often, the first imaging modality used in eye and orbit assessment. The indications of ophthalmic US cover a wide range of disease where direct clinical assessment is impossible or of little value. Doppler US enhances the ability to assess blood flow in the main arteries and veins. In order to take full advantage of all the possibilities US has to offer the examiner thorough knowledge of the examination technique and normal US anatomy of the eye and orbit is required. This paper reviews the basics of the examination technique and ultrasound anatomy of the eye and orbit.

  1. Nilpotent orbits in real symmetric pairs

    CERN Document Server

    Dietrich, Heiko; Ruggeri, Daniele; Trigiante, Mario

    2016-01-01

    In the classification of stationary solutions in extended supergravities with symmetric scalar manifolds, the nilpotent orbits of a real symmetric pair play an important role. In this paper we discuss two approaches to determining the nilpotent orbits of a real symmetric pair. We apply our methods to an explicit example, and thereby classify the nilpotent orbits of SL_2(R)^4 acting on the fourth tensor power of the natural 2-dimensional SL_2(R)-module. This makes it possible to classify all stationary solutions of the so-called STU-supergravity model.

  2. Orbital interactions - A new geometrical formalism

    Science.gov (United States)

    Greenberg, R.

    1982-01-01

    The geometry of encounters between two bodies on independent Keplerian orbits around a third body is considered by a novel analysis, which avoids approximations made in previous studies. For the case of most of the applications considered, the formulas for collision frequencies and orbital element rates of change due to close approaches which comprise the method agree with past results. It is shown that the method can be extended to such other applications as the consideration of oscillations in orbital elements due to secular perturbations, and the computation of probabilities of escape from the system.

  3. 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.

  4. Novel Detection of Optical Orbital Angular Momentum

    Science.gov (United States)

    2014-11-16

    Spreeuw, J. P . Woerdman, “ Orbital angular momentum of light and the transformation of Laguerre-Gaussian laser modes,” Phys. Rev. A, 45(11), 8185-8189...AFRL-RD-PS- AFRL-RD-PS TR-2014-0045 TR-2014-0045 Novel Detection of Optical Orbital Angular Momentum David Voelz Klipsch... Orbital Angular Momentum FA9451-13-1-0261 GR0004113 David Voelz Klipsch School of ECE New Mexico State University MSC 3-O, PO Box 30001 Las Cruces, NM

  5. Distant retrograde orbits for the Moon's exploration

    Science.gov (United States)

    Sidorenko, Vladislav

    We discuss the properties of the distant retrograde orbits (which are called quasi-satellite orbits also) around Moon. For the first time the distant retrograde orbits were described by J.Jackson in studies on restricted three body problem at the beginning of 20th century [1]. In the synodic (rotating) reference frame distant retrograde orbit looks like an ellipse whose center is slowly drifting in the vicinity of minor primary body while in the inertial reference frame the third body is orbiting the major primary body. Although being away the Hill sphere the third body permanently stays close enough to the minor primary. Due to this reason the distant retrograde orbits are called “quasi-satellite” orbits (QS-orbits) too. Several asteroids in solar system are in a QS-orbit with respect to one of the planet. As an example we can mention the asteroid 2002VE68 which circumnavigates Venus [2]. Attention of specialists in space flight mechanics was attracted to QS-orbits after the publications of NASA technical reports devoted to periodic moon orbits [3,4]. Moving in QS-orbit the SC remains permanently (or at least for long enough time) in the vicinity of small celestial body even in the case when the Hill sphere lies beneath the surface of the body. The properties of the QS-orbit can be studied using the averaging of the motion equations [5,6,7]. From the theoretical point of view it is a specific case of 1:1 mean motion resonance. The integrals of the averaged equations become the parameters defining the secular evolution of the QS-orbit. If the trajectory is robust enough to small perturbations in the simplified problem (i.e., restricted three body problem) it may correspond to long-term stability of the real-world orbit. Our investigations demonstrate that under the proper choice of the initial conditions the QS-orbits don’t escape from Moon or don’t impact Moon for long enough time. These orbits can be recommended as a convenient technique for the large

  6. 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.

  7. 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.

  8. Study of the transfer between libration point orbits and lunar orbits in Earth-Moon system

    Science.gov (United States)

    Cheng, Yu; Gómez, Gerard; Masdemont, Josep J.; Yuan, Jianping

    2017-02-01

    This paper is devoted to the study of the transfer problem from a libration point orbit of the Earth-Moon system to an orbit around the Moon. The transfer procedure analysed has two legs: the first one is an orbit of the unstable manifold of the libration orbit and the second one is a transfer orbit between a certain point on the manifold and the final lunar orbit. There are only two manoeuvres involved in the method and they are applied at the beginning and at the end of the second leg. Although the numerical results given in this paper correspond to transfers between halo orbits around the L_1 point (of several amplitudes) and lunar polar orbits with altitudes varying between 100 and 500 km, the procedure we develop can be applied to any kind of lunar orbits, libration orbits around the L_1 or L_2 points of the Earth-Moon system, or to other similar cases with different values of the mass ratio.

  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. Imaging of orbital disorders in pediatric patients

    Energy Technology Data Exchange (ETDEWEB)

    Gorospe, Luis; Royo, Aranzazu; Berrocal, Teresa; Garcia-Raya, Pilar; Moreno, Pilar [Department of Radiology, La Paz University Hospital, Paseo de la Castellana 261, 28046 Madrid (Spain); Abelairas, Jose [Department of Pediatric Ophthalmology, La Paz University Hospital, Paseo de la Castellana 261, 28046 Madrid (Spain)

    2003-08-01

    The spectrum of orbital lesions occurring in childhood is wide, including a variety of both benign and malignant disorders. Although physical examination and fundoscopy may aid in establishing the diagnosis of retro-ocular lesions, imaging remains a critical step in the evaluation of the pediatric orbit. Ultrasonography, CT, and MR imaging are the primary modalities for the evaluation of the diseased orbit, and careful observation of the characteristic radiological features usually leads to correct diagnosis; however, some of the lesions look very similar and are difficult to differentiate from each other. The purpose of this article is to review the common and unusual entities that may involve the pediatric orbit, to describe the radiological features, and to evaluate the efficacy of US, CT, and MRI in the diagnosis and management of these conditions. (orig.)

  11. Jumping Jupiter can explain Mercury's orbit

    CERN Document Server

    Roig, Fernando; DeSouza, Sandro Ricardo

    2016-01-01

    The orbit of Mercury has large values of eccentricity and inclination that cannot be easily explained if this planet formed on a circular and coplanar orbit. Here, we study the evolution of Mercury's orbit during the instability related to the migration of the giant planets in the framework of the jumping Jupiter model. We found that some instability models are able to produce the correct values of Mercury's eccentricity and inclination, provided that relativistic effects are included in the precession of Mercury's perihelion. The orbital excitation is driven by the fast change of the normal oscillation modes of the system corresponding to the perihelion precession of Jupiter (for the eccentricity), and the nodal regression of Uranus (for the inclination).

  12. Earth orbital operations supporting manned interplanetary missions

    Science.gov (United States)

    Sherwood, Brent; Buddington, Patricia A.; Whittaker, William L.

    The orbital operations required to accumulate, assemble, test, verify, maintain, and launch complex manned space systems on interplanetary missions from earth orbit are as vital as the flight hardware itself. Vast numbers of orbital crew are neither necessary nor desirable for accomplishing the required tasks. A suite of robotic techniques under human supervisory control, relying on sensors, software and manipulators either currently emergent or already applied in terrestrial settings, can make the job tractable. The mission vehicle becomes largely self-assembling, using its own rigid aerobrake as a work platform. The Space Station, having been used as a laboratory testbed and to house an assembly crew of four, is not dominated by the process. A feasible development schedule, if begun soon, could emplace orbital support technologies for exploration missions in time for a 2004 first interplanetary launch.

  13. A Simple Huckel Molecular Orbital Plotter

    Science.gov (United States)

    Ramakrishnan, Raghunathan

    2013-01-01

    A program is described and presented to readily plot the molecular orbitals from a Huckel calculation. The main features of the program and the scope of its applicability are discussed through some example organic molecules. (Contains 2 figures.)

  14. Objects orbiting the Earth in deep resonance

    CERN Document Server

    Sampaio, J C; de Moraes, R Vilhena; Fernandes, S S

    2012-01-01

    The increasing number of objects orbiting the Earth justifies the great attention and interest in the observation, spacecraft protection and collision avoidance. These studies involve different disturbances and resonances in the orbital motions of these objects distributed by the distinct altitudes. In this work, the TLE (Two-Line Elements) of the NORAD are studied observing the resonant period of the objects orbiting the Earth and the main resonance in the LEO region. The time behavior of the semi-major axis, eccentricity and inclination of some space debris are studied. Possible irregular motions are observed by the frequency analysis and by the presence of different resonant angles describing the orbital dynamics of these objects.

  15. Gravitational waves carrying orbital angular momentum

    CERN Document Server

    Bialynicki-Birula, Iwo

    2015-01-01

    Spinorial formalism is used to map every electromagnetic wave into the gravitational wave (within the linearized gravity). In this way we can obtain the gravitational counterparts of Bessel, Laguerre-Gauss, and other light beams carrying orbital angular momentum.

  16. Sclerosing Wegener's granulomatosis in the orbit

    DEFF Research Database (Denmark)

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

    2008-01-01

    and from two enucleated eyes. RESULTS: All three patients had longstanding inflammation in the orbit and involvement of the paranasal sinuses. Proptosis, impaired ocular motility and reduced visual acuity dominated the clinical picture. All histopathological specimens featured granulomatous inflammation...

  17. Amplitude damping channel for orbital angular momentum

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2010-03-01

    Full Text Available Since the pioneering work on the entanglement of the orbital angular momentum (OAM) states of light, much attention has been devoted to the subject, with particular attention into the quantum aspects of information processing using OAM. Furthermore...

  18. 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.

  19. Spin-orbit interactions of light

    CERN Document Server

    Bliokh, K Y; Nori, F; Zayats, A V

    2015-01-01

    Light carries spin and orbital angular momentum. These dynamical properties are determined by the polarization and spatial degrees of freedom of light. Modern nano-optics, photonics, and plasmonics, tend to explore subwavelength scales and additional degrees of freedom of structured, i.e., spatially-inhomogeneous, optical fields. In such fields, spin and orbital properties become strongly coupled with each other. We overview the fundamental origins and important applications of the main spin-orbit interaction phenomena in optics. These include: spin-Hall effects in inhomogeneous media and at optical interfaces, spin-dependent effects in nonparaxial (focused or scattered) fields, spin-controlled shaping of light using anisotropic structured interfaces (metasurfaces), as well as robust spin-directional coupling via evanescent near fields. We show that spin-orbit interactions are inherent in all basic optical processes, and they play a crucial role at subwavelength scales and structures in modern optics.

  20. Dealing with Uncertainties in Initial Orbit Determination

    Science.gov (United States)

    Armellin, Roberto; Di Lizia, Pierluigi; Zanetti, Renato

    2015-01-01

    A method to deal with uncertainties in initial orbit determination (IOD) is presented. This is based on the use of Taylor differential algebra (DA) to nonlinearly map the observation uncertainties from the observation space to the state space. When a minimum set of observations is available DA is used to expand the solution of the IOD problem in Taylor series with respect to measurement errors. When more observations are available high order inversion tools are exploited to obtain full state pseudo-observations at a common epoch. The mean and covariance of these pseudo-observations are nonlinearly computed by evaluating the expectation of high order Taylor polynomials. Finally, a linear scheme is employed to update the current knowledge of the orbit. Angles-only observations are considered and simplified Keplerian dynamics adopted to ease the explanation. Three test cases of orbit determination of artificial satellites in different orbital regimes are presented to discuss the feature and performances of the proposed methodology.

  1. 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.

  2. Collision orbits in the presence of perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Cano, A. [Departamento de Algebra, Facultad de CC. Matematicas, Universidad Complutense de Madrid, Madrid (Spain)]. E-mail: antonio_diazcano@mat.ucm.es; Gonzalez-Gascon, F. [Departamento de Fisica Teorica II, Facultad de CC. Fisicas, Universidad Complutense de Madrid, Madrid (Spain)

    2006-10-16

    It is shown that for particles moving in a plane under the action of attracting central potentials and a perturbing force (potential but not central), orbits representing the falling down of the particle to the center of force exist.

  3. NASA Orbital Debris Requirements and Best Practices

    Science.gov (United States)

    Hull, Scott

    2014-01-01

    Limitation of orbital debris accumulation is an international and national concern, reflectedin NASA debris limitation requirements. These requirements will be reviewed, along with some practices that can be employed to achieve the requirements.

  4. Pressureless Orbital Decompression for Myopic Proptosis.

    Science.gov (United States)

    Rajak, Saul N; McGovern, Richard A; Selva, Dinesh

    2017-01-01

    Orbital decompression surgery increases the orbital volume. It has rarely been used for proptosis of the large highly myopic globe. However, external decompression surgery carries significant risks because of the large thin-walled globe. The authors report the first use of endoscopic medial wall orbital decompression surgery in this setting to obviate the risk of globe pressure.Endoscopic medial wall decompression brought about a 4 mm reduction of proptosis, correction of exotropia and elimination of retrobulbar ache providing good symmetry with the fellow eye.Endoscopic medial wall orbital decompression can be very effective for correcting the proptosis of high myopia and minimizes the risk of damage to the very large, thin-walled globe.

  5. Fitting Planetary Orbits with a Spreadsheet.

    Science.gov (United States)

    Bridges, Richard

    1995-01-01

    Describes how to fit binocular observations of the planets to a theoretical model of circular orbits using a modern computer spreadsheet, from which fundamental data about the solar system may be deduced. (AIM)

  6. 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...

  7. 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.

  8. Third-generation muffin–tin orbitals

    Indian Academy of Sciences (India)

    O K Andersen; T Saha-Dasgupta; S Ezhov

    2003-01-01

    By the example of $sp^3$-bonded semiconductors, we illustrate what 3rd-generation muffin–tin orbitals (MTOs) are. We demonstrate that they can be downfolded to smaller and smaller basis sets: $sp^3d^{10}, sp^3$, and bond orbitals. For isolated bands, it is possible to generate Wannier functions a priori. Also for bands, which overlap other bands, Wannier-like MTOs can be generated a priori. Hence, MTOs have a unique capability for providing chemical understanding.

  9. Orbital Evasive Target Tracking and Sensor Management

    Science.gov (United States)

    2012-03-30

    orbits to simulate the space resource management for situation awareness. We adopted NASA’s General Mission Analysis Tool ( GMAT ) for space target...realistic satellite orbits to simulate the space resource management for situation awareness. We adopted NASA’s General Mission Analysis Tool ( GMAT ...Analysis Tool ( GMAT ) for space target tracking with multiple space borne observers. The results indicate that the game theoretic approach is more effective

  10. Nonminimal global monopoles and bound orbits

    CERN Document Server

    Nucamendi, U; Sudarsky, D; Nucamendi, Ulises; Salgado, Marcelo; Sudarsky, Daniel

    2000-01-01

    We perform a numerical analysis of the gravitational field of a global monopole coupled nonminimally to gravity, and find that, for some given nonminimal couplings (in constrast with the minimal coupling case), there is an attractive region where bound orbits exist. We exhibit the behavior of the frequency shifts that would be associated with `rotation curves' of stars in circular orbits in the spacetimes of such global monopoles.

  11. [Metallic foreign bodies in the orbit].

    Science.gov (United States)

    Skorek, Andrzej; Gębka, Andrzej; Babiński, Dariusz; Raczyńska, Dorota

    2013-01-01

    Authors present a case of metallic foreign bodies (part of the hammer) in apex of the orbit in a 57-year-old man. In CT scan it was localized between rectus lateral muscle and optic nerve. We remove it through transantral approach. We discuss about diagnosis and indication to transnasal and transsinusal (trough maxillary and ethmoidal sinuses) approaches to the retrobulbar part of the orbit.

  12. Reducing or enhancing chaos using periodic orbits.

    Science.gov (United States)

    Bachelard, R; Chandre, C; Leoncini, X

    2006-06-01

    A method to reduce or enhance chaos in Hamiltonian flows with two degrees of freedom is discussed. This method is based on finding a suitable perturbation of the system such that the stability of a set of periodic orbits changes (local bifurcations). Depending on the values of the residues, reflecting their linear stability properties, a set of invariant tori is destroyed or created in the neighborhood of the chosen periodic orbits. An application on a paradigmatic system, a forced pendulum, illustrates the method.

  13. The late treatment of vertical orbital dystopia resulting from an orbital roof fracture.

    Science.gov (United States)

    Horowitz, J H; Persing, J A; Winn, H R; Edgerton, M T

    1984-12-01

    Traumatic fracture of the orbital roof is uncommon and it may be unrecognized at the time of injury. In this article we describe a patient with progressive vertical orbital dystopia four years after he sustained a fracture of his "frontal" bone. Surgical exploration revealed an orbital roof fracture complicated by a chronic dural leak. An intracranial-extracranial approach through a modified frontal craniotomy provided excellent visualization to elevate the bony orbit and globe safely and repair the dural tear. Our study illustrates the need to correct residual soft tissue deformity at a second operation. Orbital roof fracture is a complex injury and is best treated by a multispecialty team using the methods learned from the treatment of patients with congenital orbital dystopia.

  14. Orbital relaxation effects on Kohn–Sham frontier orbital energies in density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, DaDi [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zheng, Xiao, E-mail: xz58@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Li, Chen [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Yang, Weitao, E-mail: weitao.yang@duke.edu [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Key Laboratory of Theoretical Chemistry of Environment, School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China)

    2015-04-21

    We explore effects of orbital relaxation on Kohn–Sham frontier orbital energies in density functional theory by using a nonempirical scaling correction approach developed in Zheng et al. [J. Chem. Phys. 138, 174105 (2013)]. Relaxation of Kohn–Sham orbitals upon addition/removal of a fractional number of electrons to/from a finite system is determined by a systematic perturbative treatment. The information of orbital relaxation is then used to improve the accuracy of predicted Kohn–Sham frontier orbital energies by Hartree–Fock, local density approximation, and generalized gradient approximation methods. The results clearly highlight the significance of capturing the orbital relaxation effects. Moreover, the proposed scaling correction approach provides a useful way of computing derivative gaps and Fukui quantities of N-electron finite systems (N is an integer), without the need to perform self-consistent-field calculations for (N ± 1)-electron systems.

  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. Stability of Frozen Orbits Around Europa

    Science.gov (United States)

    Cardoso Dos Santos, Josué; Vilhena de Moraes, R.; Carvalho, J. S.

    2013-05-01

    Abstract (2,250 Maximum Characters): A planetary satellite of interest at the present moment for the scientific community is Europa, one of the four largest moons of Jupiter. There are some missions planned to visit Europa in the next years, for example, Jupiter Europa Orbiter (JEO, NASA) and Jupiter IcyMoon Explorer (JUICE, ESA). In this work we are formulating theories and constructing computer programs to be used in the design of aerospace tasks as regards the stability of artificial satellite orbits around planetary satellites. The studies are related to translational motion of orbits around planetary satellites considering polygenic perturbations due to forces, such as the nonspherical shape of the central body and the perturbation of the third body. The equations of motion will be developed in closed form to avoid expansions in eccentricity and inclination. For a description of canonical formalism are used the Delaunay canonical variables. The canonical set of equations, which are nonlinear differential equations, will be used to study the stability of orbits around Europa. We will use a simplified dynamic model, which considers the effects caused by non-uniform distribution of mass of Europa (J2, J3 and C22) and the gravitational attraction of Jupiter. Emphasis will be given to the case of frozen orbits, defined as having almost constant values of eccentricity, inclination, and argument of pericentre. An approach will be used to search for frozen orbits around planetary satellites and study their stability by applying a process of normalization of Hamiltonian. Acknowledges: FAPESP

  17. [Ethmoidal mucocele after transpalpebral bony orbital decompression].

    Science.gov (United States)

    Gire, J; Facon, F; Guigou, S; Fauquier, S; Malet, T

    2012-10-01

    We report a case of a late ethmoidal mucocele occurring after transpalpebral bony orbital decompression. A 39-year-old man presented with a recurrence of a right-sided proptosis without signs of orbital inflammation. The patient had undergone bilateral transpalpebral bony orbital decompression for dysthyroid orbitopathy 2 years prior. Orbital CT scan showed a large mucocele in the supero-lateral right ethmoidal sinus with lateral extension to the medial rectus. The patient was therefore referred to an ear, nose and throat (ENT) surgeon, who performed an anterior ethmoidectomy with marsupialization and drainage of the mucocele via an endoscopic approach. A complete postoperative resolution of proptosis was observed without recurrence of the mucocele to date, approximately 6 months postoperative. Sinus complications occurring after orbital decompression may include sinusitis, hematoma, imploding antrum syndrome and mucoceles. Recurrent proptosis secondary to an ethmoidal mucocele is a rare event after bony orbital decompression surgery, with only two cases reported in the international literature. Management requires ophthalmologic diagnosis and collaboration between the ophthalmologist and otorhinolaryngologist. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  18. Stochastic Analysis of Orbital Lifetimes of Spacecraft

    Science.gov (United States)

    Sasamoto, Washito; Goodliff, Kandyce; Cornelius, David

    2008-01-01

    A document discusses (1) a Monte-Carlo-based methodology for probabilistic prediction and analysis of orbital lifetimes of spacecraft and (2) Orbital Lifetime Monte Carlo (OLMC)--a Fortran computer program, consisting of a previously developed long-term orbit-propagator integrated with a Monte Carlo engine. OLMC enables modeling of variances of key physical parameters that affect orbital lifetimes through the use of probability distributions. These parameters include altitude, speed, and flight-path angle at insertion into orbit; solar flux; and launch delays. The products of OLMC are predicted lifetimes (durations above specified minimum altitudes) for the number of user-specified cases. Histograms generated from such predictions can be used to determine the probabilities that spacecraft will satisfy lifetime requirements. The document discusses uncertainties that affect modeling of orbital lifetimes. Issues of repeatability, smoothness of distributions, and code run time are considered for the purpose of establishing values of code-specific parameters and number of Monte Carlo runs. Results from test cases are interpreted as demonstrating that solar-flux predictions are primary sources of variations in predicted lifetimes. Therefore, it is concluded, multiple sets of predictions should be utilized to fully characterize the lifetime range of a spacecraft.

  19. 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...

  20. Analysis of unstable periodic orbits and chaotic orbits in the one-dimensional linear piecewise-smooth discontinuous map

    Energy Technology Data Exchange (ETDEWEB)

    Rajpathak, Bhooshan, E-mail: bhooshan@ee.iitb.ac.in; Pillai, Harish K., E-mail: hp@ee.iitb.ac.in [Department of Electrical Engineering, IIT Bombay, Mumbai 400076 (India); Bandyopadhyay, Santanu, E-mail: santanu@me.iitb.ac.in [Department of Energy Science and Engineering, IIT Bombay, Mumbai 400076 (India)

    2015-10-15

    In this paper, we analytically examine the unstable periodic orbits and chaotic orbits of the 1-D linear piecewise-smooth discontinuous map. We explore the existence of unstable orbits and the effect of variation in parameters on the coexistence of unstable orbits. Further, we show that this structuring is different from the well known period adding cascade structure associated with the stable periodic orbits of the same map. Further, we analytically prove the existence of chaotic orbit for this map.

  1. Orbital Elements Evolution Due to a Perturbing Body in an Inclined Elliptical Orbit

    Science.gov (United States)

    Rahoma, W. A.

    2014-09-01

    This paper intends to highlight the effect of the third-body in an inclined orbit on a spacecraft orbiting the primary mass. To achieve this goal, a new origin of coordinate is introduced in the primary and the X-axis toward the node of the spacecraft. The disturbing function is expanded up to the second order using Legendre polynomials. A double-averaged analytical model is exploited to produce the evolutions of mean orbital elements as smooth curves.

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

    Science.gov (United States)

    2016-09-16

    Orbit Covariance Estimation and ANalysis (OCEAN) high precision orbit deter- mination tool in order to determine the suitability of each model for...Covariance Estimation and ANalysis (OCEAN) software was used to preform high precision orbit estimations. OCEAN is a highly configurable, database...lowest RMS position difference for each time span is highlighted in bold text . The Jacchia-Bowman 2008 models are labeled as JB08, the NRLMSISE-00

  3. Frontal mucocele with an accompanying orbital abscess mimicking a fronto-orbital mucocele: case report

    OpenAIRE

    Akkuzu Guzin; Aydin Erdinc; Akkuzu Babur; Bilezikci Banu

    2006-01-01

    Abstract Background Mucoceles are slowly expanding cystic lesions with respiratory epithelium containing mucus most commonly affecting the frontal and ethmoidal sinuses. They are caused by obstruction of sinus ostium. Mucoceles exert pressure on the bony boundaries and due to the proximity to the brain and orbit extension to these areas are common. Case presentation A case of a frontal mucocele with an accompanying orbital abscess mimicking a fronto-orbital mucocele is reported. A 77 year old...

  4. Physics of orbital degree of freedom - resonant X-ray scattering for observation of orbital ordering

    CERN Document Server

    Hirota, K

    2003-01-01

    Orbital degree of freedom plays very important roles in electric and magnetic properties in strongly correlated electron systems. The method for measurement of orbital ordering, however, has been limited so far. Recently it has been pointed out that the resonant X-ray scattering (RXS) technique is a very powerful tool to observe the ordering. In ths paper, the principle of RXS and the recent development are described after the general introduction of orbital degree of freedom. Finally the future in orbital physics will be discussed. (author)

  5. Minimum-fuel aerodynamic orbital plane change maneuvers. [for Space Shuttle Orbiters

    Science.gov (United States)

    Joosten, B. K.; Pierson, B. L.

    1981-01-01

    Several minimum-fuel, aerodynamically controlled, orbital plane change problems are formulated and solved as optimal control problems. A gradient projection algorithm is used to iteratively modify both the control functions, angle of attack and bank angle, and two control parameters to obtain the optimal trajectory. The atmospheric flight profile is combined with two Keplerian (two-body vacuum flight) arcs so that a complete orbit-to-orbit analysis results. The vehicle used in this investigation is the Space Transportation System Shuttle Orbiter. The effects of heat load constraint level and plane change angle are analysed.

  6. The Survival of Freely Grafted Orbital Fat on Porous Polyethylene Orbital Implants in the Rabbit

    OpenAIRE

    Kim, Nam Ju; Choung, Ho Kyung; Khwarg, Sang In

    2006-01-01

    Purpose To investigate the long term survival of orbital fat grafted on a Medpor® implant as a method of preventing porous polyethylene orbital implant (Medpor®) exposure in anophthalmic sockets. Methods In one orbit in each of 8 rabbits, a small amount of retrobulbar orbital fat was grafted between the anterior surface of the Medpor® implant and overlying conjunctiva, during the enucleation and Medpor® implantation procedure. Two rabbits were sacrificed at 2, 4, 8 and 12 weeks postoperativel...

  7. Orbit Maintenance and Navigation of Human Spacecraft at Cislunar Near Rectilinear Halo Orbits

    Science.gov (United States)

    Davis, Diane; Bhatt, Sagar; Howell, Kathleen; Jang, Jiann-Woei; Whitley, Ryan; Clark, Fred; Guzzetti, Davide; Zimovan, Emily; Barton, Gregg

    2017-01-01

    Multiple studies have concluded that Earth-Moon libration point orbits are attractive candidates for staging operations. The Near Rectilinear Halo Orbit (NRHO), a member of the Earth-Moon halo orbit family, has been singularly demonstrated to meet multi-mission architectural constraints. In this paper, the challenges associated with operating human spacecraft in the NRHO are evaluated. Navigation accuracies and human vehicle process noise effects are applied to various station keeping strategies in order to obtain a reliable orbit maintenance algorithm. Additionally, the ability to absorb missed burns, construct phasing maneuvers to avoid eclipses and conduct rendezvous and proximity operations are examined.

  8. 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. PMID:26953033

  9. 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.

  10. 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.

  11. Secular orbital evolution of Jupiter family comets

    Science.gov (United States)

    Rickman, H.; Gabryszewski, R.; Wajer, P.; Wiśniowski, T.; Wójcikowski, K.; Szutowicz, S.; Valsecchi, G. B.; Morbidelli, A.

    2017-02-01

    Context. The issue of the long term dynamics of Jupiter family comets (JFCs) involves uncertain assumptions about the physical evolution and lifetimes of these comets. Contrary to what is often assumed, real effects of secular dynamics cannot be excluded and therefore merit investigation. Aims: We use a random sample of late heavy bombardment cometary projectiles to study the long-term dynamics of JFCs by a Monte Carlo approach. In a steady-state picture of the Jupiter family, we investigate the orbital distribution of JFCs, including rarely visited domains like retrograde orbits or orbits within the outer parts of the asteroid main belt. Methods: We integrate 100 000 objects over a maximum of 100 000 orbital revolutions including the Sun, a comet, and four giant planets. Considering the steady-state number of JFCs to be proportional to the total time spent in the respective orbital domain, we derive the capture rate based on observed JFCs with small perihelia and large nuclei. We consider a purely dynamical model and one where the nuclei are eroded by ice sublimation. Results: The JFC inclination distribution is incompatible with our erosional model. This may imply that a new type of comet evolution model is necessary. Considering that comets may live for a long time, we show that JFCs can evolve into retrograde orbits as well as asteroidal orbits in the outer main belt or Cybele regions. The steady-state capture rate into the Jupiter family is consistent with 1 × 109 scattered disk objects with diameters D > 2 km. Conclusions: Our excited scattered disk makes it difficult to explain the JFC inclination distribution, unless the physical evolution of JFCs is more intricate than assumed in standard, erosional models. Independent of this, the population size of the Jupiter family is consistent with a relatively low-mass scattered disk.

  12. Orbital Instability and Relaxation in Stellar Systems

    Science.gov (United States)

    Valluri, Monica; Merritt, David

    We review recent progress in understanding the role of chaos in influencing the structure and evolution of galaxies. The orbits of stars in galaxies are generically chaotic: the chaotic behavior arises in part from the intrinsically grainy nature of a potential that is composed of point masses. Even if the potential is assumed to be smooth, however, much of the phase space of non-axisymmetric galaxies is chaotic due to the presence of central density cusps or black holes. The chaotic nature of orbits implies that perturbations will grow exponentially and this in turn is expected to result in a diffusion in phase space. We show that the degree of orbital evolution is not well predicted by the growth rate of infinitesimal perturbations, i.e. by the Liapunov exponent. A more useful criterion is whether perturbations continue to grow exponentially until their scale is of order the size of the system. We illustrate these ideas in a potential consisting of N fixed point masses. Liapunov exponents are large for all values of N, but orbits become increasingly regular in their behavior as N increases; the reason is that the exponential divergence saturates at smaller and smaller distances as N is increased. The objects which lend phase space its structure and impede diffusion are the invariant tori; in the triaxial potentials we consider, a large fraction of the tori correspond to resonant (thin) orbits and their associated families of regular orbits. Perturbations to the potential destroy the resonant tori. When only a few stable resonances remain, we find that the phase space distribution of an ensemble of chaotic orbits evolves rapidly toward a nearly stationary state. This mixing process is shown to occur on timescales of a few crossing times in triaxial potentials containing massive central singularities, consistent with the rapid evolution observed in N-body simulations of galaxies with central black holes.

  13. Impact evaluation of an orbital depot on on-orbit servicing infrastructures dedicated to modularized earth-orbiting platforms

    Science.gov (United States)

    Sarton du Jonchay, Tristan; Ho, Koki

    2017-03-01

    This paper aims to quantify the responsiveness of two on-orbit servicing infrastructures providing services to multiple serviceable platforms in coplanar medium Earth orbit (MEO) and geostationary orbit (GEO). The platforms to be serviced are assumed to be made of elementary units (EUs). EUs are small standardized structural units capable of aggregating with each other and gathering the key functions of a typical satellite within the size of a 6U cubesat. The first servicing infrastructure considered in this paper, called "Without Depot" (WoD), includes a launch vehicle and a robotic servicer. The second servicing infrastructure, called "With Depot" (WD) includes a launch vehicle, a robotic servicer and an orbital depot of EUs. The responsiveness of these infrastructures is quantified using a queueing theory-based stochastic simulation on Simulink taking into account the launch and platform random failures. The metrics used to quantify the responsiveness are the service completion rate and the average waiting time before an EU is replaced over a 10-year period of operation. With respect to those metrics, it is demonstrated that WD is more responsive than WoD. However, WD is also shown to be likely to cost more than WoD. Finally, the sensitivity of the responsiveness of WD to the capacity of the orbital depot is analyzed to find the minimum storage capacity for which WD is the most responsive. This last result could be of interest for space designers dealing with the sizing of on-orbit servicing infrastructures. We believe that the concept introduced in this paper will be a critical milestone in the design of a responsive integrated space infrastructure dedicated to the development and prosperity of a new MEO/GEO economy.

  14. Cassini's Grand Finale: The Final Orbits

    Science.gov (United States)

    Spilker, Linda; Edgington, Scott

    2016-04-01

    The Cassini-Huygens mission, a joint collaboration between NASA, ESA and the Italian Space Agency, is approaching its last year of operations after nearly 12 years in orbit around Saturn. Cassini will send back its final bits of unique data on September 15th, 2017 as it plunges into Saturn's atmosphere, vaporizing and satisfying planetary protection requirements. Before that time Cassini will continue its legacy of exploration and discovery with 12 close flybys of Titan in 2016 and 2017 that will return new science data as well as sculpt the inclinations and periods of the final orbits. Even though all of our close icy satellite flybys, including those of Enceladus, are now completed, numerous Voyager-class flybys (summer solstice approaches. In November 2016 Cassini will transition to a series of orbits with peripases just outside Saturn's F ring. These 20 orbits will include close flybys of some tiny ring moons and excellent views of the F ring and outer A ring. The 126th and final close flyby of Titan will propel Cassini across Saturn's main rings and into its final orbits. Cassini's Grand Finale, starting in April 2017, is comprised of 22 orbits at an inclination of 63 degrees. Cassini will repeatedly dive between the innermost rings and the upper atmosphere of the planet providing insights into fundamental questions unattainable during the rest of the mission. Cassini will be the first spacecraft to explore this region. These close orbits provide the highest resolution observations of both the rings and Saturn, and direct in situ sampling of the ring particles, composition, plasma, Saturn's exosphere and the innermost radiation belts. Saturn's gravitational field will be measured to unprecedented accuracy, providing information on the interior structure of the planet, winds in the outer layers of Saturn's atmosphere, and the mass distribution in the rings. Probing the magnetic field will give insight into the nature of the magnetic dynamo, telling us: why the

  15. An orbital angular momentum spectrometer for electrons

    Science.gov (United States)

    Harvey, Tyler; Grillo, Vincenzo; McMorran, Benjamin

    2016-05-01

    With the advent of techniques for preparation of free-electron and neutron orbital angular momentum (OAM) states, a basic follow-up question emerges: how do we measure the orbital angular momentum state distribution in matter waves? Control of both the energy and helicity of light has produced a range of spectroscopic applications, including molecular fingerprinting and magnetization mapping. Realization of an analogous dual energy-OAM spectroscopy with matter waves demands control of both initial and final energy and orbital angular momentum states: unlike for photons, final state post-selection is necessary for particles that cannot be annihilated. We propose a magnetic field-based mechanism for quantum non-demolition measurement of electron OAM. We show that OAM-dependent lensing is produced by an operator of form U =exp iLzρ2/ℏb2 where ρ =√{x2 +y2 } is the radial position operator, Lz is the orbital angular momentum operator along z, and b is the OAM dispersion length. We can physically realize this operator as a term in the time evolution of an electron in magnetic round lens. We discuss prospects and practical challenges for implementation of a lensing orbital angular momentum measurement. This work was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under the Early Career Research Program Award # DE-SC0010466.

  16. Computed tomography of the orbital lesions

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seong Eon; Suh, Soo Jhi; Kim, Ho Kyun; Kim, Soon Yong [Kyung Hee University School of Medicine, Seoul (Korea, Republic of)

    1980-06-15

    The use of computed tomography in investigation of orbital lesions was of value for the localization of the lesions as well as making the specific diagnosis. We advocated the combined use of transverse axial section and contrast enhancement in CT as a routine procedure often including coronal section in the diagnosis of orbital lesions because of its usefulness and more precise three dimensional imaging. The authors examined 68 patients with various ophthalmic problems by EMI-CT scanner 5005 from October 1977 to November 1979. Fifty one orbital lesions out of 68 CT scans were analyzed by CT, angiography and operative findings and results were as follows; 1. Among 43 males and 25 females, their age range was from 4 months to 66 years with the most frequent age group of first decade (17 cases; 25%) 2. The distribution of the lesions was mucocele, pseudotumor, optic nerve atrophy, metastasis, lacrimal gland tumor, persistent hypertrophic primary vitreous, granulosa cell myoblastoma, hemangioma in order with 13 malignancies (25%). 3. It was difficult to differentiate pathological diagnosis of the lesions, but the character of the lesions was determined by its characteristic location, and its relationship to eyeball, optic nerve, extraocular muscles and bony orbit. 4. It was thought that more accurate diagnosis of orbital lesions could be made by development of CT scanner having fine matrix, short time exposure and thin slice in the future.

  17. 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.

  18. Collision risk management in geosynchronous orbit

    Science.gov (United States)

    Jenkin, A. B.; Peterson, G. E.

    2004-01-01

    A systematic method has been developed for managing long-term collision risk posed to operational satellites in geosynchronous orbit. Long-term collision risk reduction is achieved by proper selection of local collision probability thresholds that trigger actions to reduce risk. Such actions can be requests for more accurate orbital data, special sensor tasking, or collision avoidance maneuvers. The cost of collision risk reduction is measured by the frequency of actions taken to reduce the collision risk. This action frequency is dependent on the accuracy of the orbital data and the frequency of close approaches. A case study was performed for a set of satellites. The analysis used position error models for two-line element sets. A conjunction simulation was used to process approximately three years of archived orbital data, including publicly available two-line element sets, in order to generate conjunction statistics. From these results, a graphical representation called a χ-plot was generated. This plot permits the selection of thresholds as a function of total risk reduction and tolerable action frequency. Results of the study indicate that collision risk management in geosynchronous orbit can be very costly using data of insufficiently high accuracy, because data errors induce high action frequency for even modest amounts of collision risk reduction.

  19. Rhabdomyolysis Presenting as Orbital Apex Syndrome.

    Science.gov (United States)

    Wi, Jae Min; Chi, Mijung

    2016-01-01

    Rhabdomyolysis is a condition in which striated muscle tissue breaks down rapidly and releases muscular cell constituents into extracellular fluid and the circulation. Renal symptoms, such as acute renal failure, are major complications of rhabdomyolysis. However, no previous report of rhabdomyolysis associated with orbital complication has been issued. Here, we report the first patient of rhabdomyolysis presenting as orbital apex syndrome. A 66-year-old man presented with right periorbital swelling with erythematous patches and conjunctival chemosis. In addition, swelling, redness, and vesicles were observed in both lower legs. He was found in a drunken state with the right side of his face pressed against a table. Ophthalmic examination showed right eye fixation in all directions and ischemic change of retina. Blood testing showed elevated muscle enzyme associated with muscle destruction. And computed tomography of the orbit showed swelling of right extraocular muscles and crowding of right orbital apex. Under a diagnosis of rhabdomyolysis-associated orbital apex syndrome and central retinal artery occlusion, intravenous steroid and antibiotics therapy with intraocular pressure-lowering topicals were begun. Clinical presentation, treatment course, and follow-up are discussed.

  20. Orbital floor reconstruction with resorbable polydioxanone implants.

    Science.gov (United States)

    Gierloff, Matthias; Seeck, Niels Gunnar Karl; Springer, Ingo; Becker, StephanThomas; Kandzia, Christian; Wiltfang, Jörg

    2012-01-01

    Many different materials are proposed for reconstruction of traumatic orbital floor defects. Donor-site morbidity of autologous transplants and infections or extrusions of nonresorbable implants lead to a widespread use of resorbable, alloplastic materials such as polydioxanone (PDS). The goal of this study was to evaluate the prevalence of orbital floor fracture-related problems after surgical treatment using PDS. Ophthalmologic and clinical examinations were performed at 194 patients before orbital floor reconstruction, 14 days and 6 months after surgery (approximate defect sizes: 2 cm², n=47). Clinical findings including the ocular motility, the sensibility of the infraorbital nerve, and the position of the globe were evaluated. For statistical analysis of categorical data, confidence intervals of percentages were determined. Linear relationships between 2 variables were assessed with Pearson correlation analysis. A reduced ocular motility was diagnosed in 60 patients (31%) before surgery; in 14 patients (7%), 2 weeks; and in 10 patients (5%), 6 months after surgery. Infraorbital hypesthesia was found in 120 patients (62%) before surgery; in 47 patients (24%), 2 weeks; and in 35 patients (18%), 6 months after surgery. An enophthalmos was present in 10 patients (5%) before surgery, and in 4 patients (2%), 6 months after surgery. Our data suggest that PDS is a suitable implant for orbital floor reconstruction with acceptable low rates of infraorbital hypesthesia, bulbus motility disturbances, and enophthalmos. Polydioxanone can also be used for orbital floor defects exceeding 2 cm².

  1. Molecular diagnosis of orbital inflammatory disease.

    Science.gov (United States)

    Rosenbaum, James T; Choi, Dongseok; Wilson, David J; Grossniklaus, Hans E; Sibley, Cailin H; Harrington, Christina A; Planck, Stephen R

    2015-04-01

    Orbital inflammatory diseases include thyroid eye disease (TED), granulomatosis with polyangiitis (GPA), sarcoidosis, and nonspecific orbital inflammation (NSOI). Histopathological diagnosis usually relies on the clinical context and is not always definitive. Gene expression profiling provides diagnostic and therapeutic information in several malignancies, but its role in evaluating nonmalignant disease is relatively untested. We hypothesized that gene expression profiling could provide diagnostic information for NSOI. We collected formalin-fixed, paraffin-embedded orbital biopsies from 10 institutions and 83 subjects including 25 with thyroid eye disease, 25 nonspecific orbital inflammation, 20 healthy controls, 6 with granulomatosis with polyangiitis, and 7 with sarcoidosis. Tissues were divided into discovery and validation sets. Gene expression was quantified using Affymetrix U133 Plus 2.0 microarrays. A random forest statistical algorithm based on data from 39 probe sets identified controls, GPA, or TED with an average accuracy of 76% (p=0.02). Random forest analysis indicated that 52% of tissues from patients with nonspecific inflammation were consistent with a diagnosis of GPA. Molecular diagnosis by gene expression profiling will augment clinical data and histopathology in differentiating forms of orbital inflammatory disease.

  2. Orbital Epidermoid Cysts: A Diagnosis to Consider

    Directory of Open Access Journals (Sweden)

    Rania A. Ahmed

    2014-01-01

    Full Text Available Background. Orbital epidermoids form a rare pathological entity that is separate from dermoid cysts. They have variable clinical and radiological presentations and they should be considered in the differential diagnosis of orbital cystic lesions. This work describes the various clinical and radiological presentations of 17 cases of epidermoid cysts and the surgical outcome. Method. A prospective interventional study was conducted on 17 patients diagnosed with epidermoid cysts. Patients’ symptoms and signs were recorded; CT scan was done for all patients. All lesions were removed through anterior orbitotomy and histopathological diagnosis confirmed. Results. Mean age of patients was 16.3 years ±  10.54. Main complaints were lid swelling, masses, ocular dissimilarity, chronic pain, and ocular protrusion. Clinical signs varied from lid swelling and masses in all cases to proptosis, globe displacement, limitation of ocular motility, and scars. Radiological findings ranged from homogenous hypodense masses (58.8% to homogenous radiolucent (17.6% and heterogenous masses (23.5%. No recurrences following surgeries were reported throughout the follow-up (mean 18.8 months ±  0.72. Conclusion. Deep orbital epidemoid cysts are a separate entity that can behave like deep orbital epidermoid; however, they usually present at a relatively older age. They can be associated with increased orbital volume but not necessarily related to bony sutures.

  3. Best Mitigation Paths To Effectively Reduce Earth's Orbital Debris

    Science.gov (United States)

    Wiegman, Bruce M.

    2009-01-01

    This slide presentation reviews some ways to reduce the problem posed by debris in orbit around the Earth. It reviews the orbital debris environment, the near-term needs to minimize the Kessler syndrome, also known as collisional cascading, a survey of active orbital debris mitigation strategies, the best paths to actively remove orbital debris, and technologies that are required for active debris mitigation.

  4. Hubble Space Telescope On-orbit Transfer Function Test

    Science.gov (United States)

    Vadlamudi, N.; Blair, M. A.; Clapp, B. R.

    1992-01-01

    The paper describes the On-orbit Transfer Function Test (TFT) designed for on-orbit vibration testing of the Hubble Space Telescope (HST). The TFT provides means for extracting accurate on-orbit characteristics of HST flexible body dynamics, making it possible to check periodically the state of the vehicle on-orbit and to assess changes in modal parameters.

  5. Hyperbolic orbit and its variation of deep-space probe

    Institute of Scientific and Technical Information of China (English)

    LIU; Lin(刘林); WANG; Xin(王歆)

    2003-01-01

    While approaching the target body, the deep-space probe is orbiting hyperbolically before the maneuver. We discuss the variation of perturbed hyperbolic orbit using the method similar to that used in elliptic orbit. Ephemeris calculating and orbit control will benefit from the given analytical solution.

  6. Disruption of co-orbital (1:1) planetary resonances during gas-driven orbital migration

    CERN Document Server

    Pierens, Arnaud

    2014-01-01

    Planets close to their stars are thought to form farther out and migrate inward due to angular momentum exchange with gaseous protoplanetary disks. This process can produce systems of planets in co-orbital (Trojan or 1:1) resonance, in which two planets share the same orbit, usually separated by 60 degrees. Co-orbital systems are detectable among the planetary systems found by the Kepler mission either directly or by transit timing variations. However, no co-orbital systems have been found within the thousands of Kepler planets and candidates. Here we study the orbital evolution of co-orbital planets embedded in a protoplanetary disk using a grid-based hydrodynamics code. We show that pairs of similar-mass planets in co-orbital resonance are disrupted during large-scale orbital migration. Destabilization occurs when one or both planets is near the critical mass needed to open a gap in the gaseous disk. A confined gap is opened that spans the 60 degree azimuthal separation between planets. This alters the torq...

  7. Orbit spectral density versus stimulus identity and intensity

    Science.gov (United States)

    Lozowski, Andy G.

    2008-09-01

    A concept of orbit spectral density for a one-dimensional iterated function is presented. To compute orbit spectral density, a method of extracting low-order periodic orbits from the dynamical system defined by the iterated function is first used. All points of the dynamics are then partitioned among the periodic orbits according to a distance measure. Partition sizes estimate the density of trajectories around periodic orbits. Assigning these trajectory densities to the orbit indexes introduces the orbit spectral density. A practical computational example is presented in the context of a model olfactory system.

  8. Interfacial spin-orbit torque without bulk spin-orbit coupling

    Science.gov (United States)

    Emori, Satoru; Nan, Tianxiang; Belkessam, Amine M.; Wang, Xinjun; Matyushov, Alexei D.; Babroski, Christopher J.; Gao, Yuan; Lin, Hwaider; Sun, Nian X.

    2016-05-01

    An electric current in the presence of spin-orbit coupling can generate a spin accumulation that exerts torques on a nearby magnetization. We demonstrate that, even in the absence of materials with strong bulk spin-orbit coupling, a torque can arise solely due to interfacial spin-orbit coupling, namely, Rashba-Eldestein effects at metal/insulator interfaces. In magnetically soft NiFe sandwiched between a weak spin-orbit metal (Ti) and insulator (Al2O3 ), this torque appears as an effective field, which is significantly larger than the Oersted field and qualitatively modified by inserting an additional layer between NiFe and Al2O3 . Our findings point to unconventional routes for tuning spin-orbit torques by engineering interfacial electric dipoles.

  9. On the co-orbital motion of two planets in quasi-circular orbits

    CERN Document Server

    Robutel, Philippe

    2013-01-01

    We develop an analytical Hamiltonian formalism adapted to the study of the motion of two planets in co-orbital resonance. The Hamiltonian, averaged over one of the planetary mean longitude, is expanded in power series of eccentricities and inclinations. The model, which is valid in the entire co-orbital region, possesses an integrable approximation modeling the planar and quasi-circular motions. First, focusing on the fixed points of this approximation, we highlight relations linking the eigenvectors of the associated linearized differential system and the existence of certain remarkable orbits like the elliptic Eulerian Lagrangian configurations, the Anti-Lagrange (Giuppone et al., 2010) orbits and some second sort orbits discovered by Poincar\\'e. Then, the variational equation is studied in the vicinity of any quasi-circular periodic solution. The fundamental frequencies of the trajectory are deduced and possible occurrence of low order resonances are discussed. Finally, with the help of the construction of...

  10. 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.

  11. Multiple-Orbit Simulations of Binary Neutron Stars

    CERN Document Server

    Suh, InSaeng; Haywood, J Reese; Lan, N Q

    2016-01-01

    We study the general relativistic hydrodynamic evolution of neutron stars in binary orbits and analyze the equation of state dependence of the orbits as the stars approach the inner most last stable circular orbit. We show that by employing a conformally flat condition on the metric, one can stably numerically evolve ~100 quasi-circular orbits and could straightforwardly extend the calculation to the ~10,000 orbits needed to follow stars through the LIGO frequency band. We apply this code to orbiting neutron stars in the quasi-circular orbit approximation to both demonstrate the stability of this approach and explore the equation of state dependence of the orbital properties. We employ variety of available realistic neutron star equations of state as well as a Gamma=2 polytrope. We confirm that both the orbital and emergent gravity wave frequency evolve more slowly for a softer equation of state as the stars approach the innermost stable circular orbit.

  12. An analysis of near-circular lunar mapping orbits

    Indian Academy of Sciences (India)

    R V Ramanan; V Adimurthy

    2005-12-01

    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 terms that make major contributions to the orbital behaviour are identified through many case studies.It is found that for low circular orbits,the 7th and the 9th zonal harmonics have predominant effect in the case of orbits for which the evolution is stable and the life is longer,and also in the case of orbits for which the evolution is unstable and a crash takes place in a short duration.By analysing the contribution of the harmonic terms to the orbit behaviour,the appropriate near-circular orbit characteristics are identified.

  13. Theory of Secular Chaos and Mercury's Orbit

    CERN Document Server

    Lithwick, Yoram

    2010-01-01

    We study the chaotic orbital evolution of planetary systems, focusing on secular (i.e., orbit-averaged) interactions, because these often dominate on long timescales. We first focus on the evolution of a test particle that is forced by multiple massive planets. To linear order in eccentricity and inclination, its orbit precesses with constant frequencies. But nonlinearities can shift the frequencies into and out of secular resonance with the planets' eigenfrequencies, or with linear combinations of those frequencies. The overlap of these nonlinear secular resonances drive secular chaos in planetary systems. We quantify the resulting dynamics for the first time by calculating the locations and widths of nonlinear secular resonances. When results from both analytical calculations and numerical integrations are displayed together in a newly developed "map of the mean momenta" (MMM), the agreement is excellent. This map is particularly revealing for non-coplanar planetary systems and demonstrates graphically that...

  14. 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.

  15. Periodic orbits of planets in binary systems

    Science.gov (United States)

    Voyatzis, G.

    2017-03-01

    Periodic solutions of the three body problem are very important for understanding its dynamics either in a theoretical framework or in various applications in celestial mechanics. In this paper we discuss the computation and continuation of periodic orbits for planetary systems. The study is restricted to coplanar motion. Starting from known results of two-planet systems around single stars, we perform continuation of solutions with respect to the mass and approach periodic orbits of single planets in two-star systems. Also, families of periodic solutions can be computed for fixed masses of the primaries. When they are linearly stable, we can conclude about the existence of phase space domains of long-term orbital stability.

  16. Orbital Debris Shape Characterization Project Abstract

    Science.gov (United States)

    Pease, Jessie

    2016-01-01

    I have been working on a project to further our understanding of orbital debris by helping create a new dataset previously too complex to be implemented in past orbital debris propagation models. I am doing this by creating documentation and 3D examples and illustrations of the shape categories. Earlier models assumed all orbital debris to be spherical aluminum fragments. My project will help expand our knowledge of shape populations to 6 categories: Straight Needle/Rod/Cylinder, Bent Needle/Rod/Cylinder, Flat Plate, Bent Plate, Nugget/Parallelepiped/Spheroid, and Flexible. The last category, Flexible, is still up for discussion and may be modified. These categories will be used to characterize fragments in the DebriSat experiment.

  17. 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.

  18. MU radar measurements of orbital debris

    Science.gov (United States)

    Sato, Toru; Kayama, Hidetoshi; Furusawa, Akira; Kimura, Iwane

    1990-04-01

    Distributions of orbital debris versus height and scattering cross section are determined from a series of observations made with a high-power VHF Doppler radar (MU radar) of Japan. An automated data processing algorithm has been developed to discriminate echoes of orbiting objects from those of undesired signals such as meteor trail echoes or lightning atmospherics. Although the results are preliminary, they showed good agreement with those from NORAD tracking radar observations using a much higher frequency. It is found that the collision frequency of a Space Station of 1 km x 1 km size at an altitude of 500 km with orbiting debris is expected to be as high as once per two years.

  19. Duality orbits of non-geometric fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Dibitetto, G.; Roest, D. [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Fernandez-Melgarejo, J.J. [Grupo de Fisica Teorica y Cosmologia, Dept. de Fisica, University of Murcia, Campus de Espinardo, 30100-Murcia (Spain); Marques, D. [Institut de Physique Theorique, CEA/ Saclay, 91191 Gif-sur-Yvette Cedex (France)

    2012-11-15

    Compactifications in duality covariant constructions such as generalised geometry and double field theory have proven to be suitable frameworks to reproduce gauged supergravities containing non-geometric fluxes. However, it is a priori unclear whether these approaches only provide a reformulation of old results, or also contain new physics. To address this question, we classify the T- and U-duality orbits of gaugings of (half-)maximal supergravities in dimensions seven and higher. It turns out that all orbits have a geometric supergravity origin in the maximal case, while there are non-geometric orbits in the half-maximal case. We show how the latter are obtained from compactifications of double field theory. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Orbital subperiosteal hematoma from scuba diving.

    Science.gov (United States)

    Rosenberry, Clark; Angelidis, Matthew; Devita, Diane

    2010-09-01

    Only a few cases of nontraumatic orbital subperiosteal hematoma due to scuba diving have been reported, and this is the first of such cases that underwent surgical intervention. This injury results from negative pressure within the face mask, suctioning orbital tissues into the mask after incomplete equilibration of pressure on descent. Valsalva maneuver is a second mechanism implicated in the etiology of this injury. Recognition of this injury is of the utmost importance because vision loss is a possible complication if there is compression of the optic nerve or increased intraocular pressure. In many cases of nontraumatic orbital hematoma, conservative management is adequate; however, this case was an exception due to worsening exam findings. Divers may be able to prevent this injury by frequent and gentle equilibration of mask pressure on descent.

  1. Congenital Orbital Teratoma with Unilateral Proptosis.

    Science.gov (United States)

    Gulzar, Rubina; Shahid, Ruqaiya; Mirza, Talat

    2017-03-01

    Teratoma is a rare tumor, containing structures originating from all three germinal layers. The most frequent location of teratoma is the gonads. Orbital teratoma is extremely rare. In 1969, Jensen reported that only 40 cases of orbital teratoma existed in the world. We describe a rare case of orbital teratoma in a 15-day girl who presented with marked proptosis of the left eye. The eyeball was embedded within the mass that could be seen all around the globe. Orbitectomy was performed with the impression of retinoblastoma. Histopathological examination was reported as benign mature cystic teratoma; no immature component was identified. The case is being reported because of its rarity and also to highlight the use of modern neuroimaging techniques in making an accurate preoperative diagnosis, which helps in better operative management of these patients.

  2. The GEOS-3 orbit determination investigation

    Science.gov (United States)

    Pisacane, V. L.; Eisner, A.; Yionoulis, S. M.; Mcconahy, R. J.; Black, H. D.; Pryor, L. L.

    1978-01-01

    The nature and improvement in satellite orbit determination when precise altimetric height data are used in combination with conventional tracking data was determined. A digital orbit determination program was developed that could singly or jointly use laser ranging, C-band ranging, Doppler range difference, and altimetric height data. Two intervals were selected and used in a preliminary evaluation of the altimeter data. With the data available, it was possible to determine the semimajor axis and eccentricity to within several kilometers, in addition to determining an altimeter height bias. When used jointly with a limited amount of either C-band or laser range data, it was shown that altimeter data can improve the orbit solution.

  3. Orbital deletion procedure and its applications

    Institute of Scientific and Technical Information of China (English)

    莫亦荣; 林梦海; 吴玮; 张乾二

    1999-01-01

    The orbital deletion procedure is introduced, which is suited to quantitatively investigating the electronic delocalization effiect in earboeations and boranes. While the routine, ab initio molecular orbital methods can generate wavefunetions for real systems where all electrons are delocalized, the present orbital deletion procedure can generate wavefunctions for hypothetical reference molecules where electronic delocalization effect is deactivated. The latter wavefunetion normlly corresponds In the most stable resonance structure in terms of the resonance theory. By comparing and analyzing the delocalized and the localized wavefunetions, one can obtain a quantitative and instinct pieture to show how electronic deloealizalion inside a molecule affects the molecular structure, energy as well as other physical properties. Two examples are detailedly discussed. The first is related to the hypercoujugation of alkyl groups in carbocations and a comparison of the order of stability of carbocations is made, T

  4. The Unorthodox Orbits of Substructure Halos

    CERN Document Server

    Ludlow, Aaron D; Springel, Volker; Jenkins, Adrian; Frenk, Carlos S; Helmi, Amina

    2008-01-01

    We use numerical simulations to study the properties of substructure within galaxy-sized dark matter halos. Our study extends previous work by considering the whole population of subhalos physically associated with the main system; these are subhalos that have at some time been within the virial radius of the main progenitor and have survived as self-bound entities to z=0. We find that this population extends beyond three times the virial radius and contains objects on extreme orbits. We trace the origin of these unorthodox orbits to multiple-body interactions acting during the tidal dissociation of bound groups. Multiple-body interactions affect primarily low-mass subhalos and push them onto higher energy orbits, resulting in a strong mass-dependent bias in the spatial distribution and kinematics of associated subhalos: the lower the subhalo mass at accretion time, the less concentrated and kinematically hotter their descendant population. Our findings imply that subhalos identified within the virial radius ...

  5. Ultrasound features of orbital granular cell tumor.

    Science.gov (United States)

    Ayres, Bernadete; Miller, Neil R; Eberhart, Charles G; Dibernardo, Cathy W

    2009-01-01

    The authors report the echographic characteristics of a rare orbital granular cell tumor and correlate these findings with histopathology. A 56-year-old woman presented with proptosis. Complete ophthalmic and ultrasound examinations were performed. Ultrasound revealed an oval, well-outlined orbital mass in the intraconal space with low-medium reflectivity and regular internal structure. An orbitotomy with complete excision of the tumor was performed. Histopathologic evaluation showed sheets and nests of cells with abundant eosinophilic and granular cytoplasm in a uniform distribution throughout the lesion. The echographic characteristics correlated well with the morphologic surgical findings and the histologic architecture. This is the first report describing the echographic characteristics of orbital granular cell tumor.

  6. Orbital Motion in Outer Solar System

    CERN Document Server

    Klacka, J; Klacka, Jozef; Gajdosik, Martin

    1999-01-01

    Motion of a point mass in gravitational fields of the Sun and of the galactic disk is studied. Fundamental features of the motion are found by investigating the time-averaged differential equations for orbital evolution. Several types of possible orbits are mathematically exactly derived in a strictly analytical way. The relation $a^{3} ~ P^{2} = f (e_{0}, i_{0}, \\omega_{0})$ between semimajor axis a and period P of the change of osculating orbital elements is found (the index 0 denotes initial values of the quantities). Due to conservation of energy in potential fields a is a constant. Moreover, the component of angular momentum perpendicular to the galactic plane is conserved. Due to these facts the system of equations reduces to two equations for either (e, $\\omega$), or (i, $\\omega$) (the length of the ascending node does not enter the equations for a, e, i, $\\omega$ and is not solved here).

  7. Ghost Imaging Using Orbital Angular Momentum

    Institute of Scientific and Technical Information of China (English)

    赵生妹; 丁建; 董小亮; 郑宝玉

    2011-01-01

    We present a novel encoding scheme in a ghost-imaging system using orbital angular momentum. In the signal arm, object spatial information is encoded as a phase matrix. For an N-grey-scale object, different phase matrices, varying from 0 to K with increment n/N, are used for different greyscales, and then they are modulated to a signal beam by a spatial light modulator. According to the conservation of the orbital angular momentum in the ghost imaging system, these changes will give different coincidence rates in measurement, and hence the object information can be extracted in the idler arm. By simulations and experiments, the results show that our scheme can improve the resolution of the image effectively. Compared with another encoding method using orbital angular momentum, our scheme has a better performance for both characters and the image object.%We present a novel encoding scheme in a ghost-imaging system using orbital angular momentum.In the signal arm,object spatial information is encoded as a phase matrix.For an N-grey-scale object,different phase matrices,varying from 0 to π with increment π/N,are used for different greyscales,and then they are modulated to a signal beam by a spatial light modulator.According to the conservation of the orbital angular momentum in the ghost imaging system,these changes will give different coincidence rates in measurement,and hence the object information can be extracted in the idler arm.By simulations and experiments,the results show that our scheme can improve the resolution of the image effectively.Compared with another encoding method using orbital angular momentum,our scheme has a better performance for both characters and the image object.

  8. Neurosurgical involvement in tumors of the orbit.

    Science.gov (United States)

    Long, D M

    1985-01-01

    The neurosurgeon has a great deal to offer in the therapy of orbital tumors. Dr. Dandy's supposition that all orbital tumors could be approached by the intracranial route is certainly correct, but technical advances have made the medial and lateral approaches to the orbit more useful for most tumors which are confined to the orbit (22, 25). For those which involve the posterior orbit and canal and have intracranial extensions, the intracranial approach is excellent. Since Dandy's first description of the procedure in 1922, there have been 29 patient reports concerning the results of transcranial canalicular decompression for non-traumatic causes. The most common diagnosis was meningioma (15), and other tumor diagnoses were fibrous dysplasia (7) and hemangioma (2). One-third of the patients were improved; one-third had vision stabilized; and one-third were made worse by surgery. Modern techniques with the microscope and high speed drill have greatly improved these results. Our own experience in the decompression of 15 canals in 11 patients is as follows. There were six patients with meningioma, and two were bilateral. Three patients were found to have a vascular dolichoectasis and one patient had an hemangioma, and in two patients no compression was identified. Immediately postoperatively, two-thirds of the patients were improved, and only one eye (representing 6.7% of the nerves decompressed) was worsened. This resulted from an attempt to totally remove an adherent sheath meningioma. Long-term follow-up median 34 months has demonstrated maintenance of these gains. Eighty percent of the patients have improved or remained stable. These data indicate that the procedure described can be done safely without major risk of visual loss. The neurosurgeon should play an increasingly important role in the evaluation and therapy of posteriorly placed orbital tumors and unexplained compressive optic neuropathy.

  9. Hooke, orbital motion, and Newton's Principia

    Science.gov (United States)

    Nauenberg, Michael

    1994-04-01

    A detailed analysis is given of a 1685 graphical construction by Robert Hooke for the polygonal path of a body moving in a periodically pulsed radial field of force. In this example the force varies linearly with the distance from the center. Hooke's method is based directly on his original idea from the mid-1660s that the orbital motion of a planet is determined by compounding its tangential velocity with a radial velocity impressed by the gravitational attraction of the sun at the center. This hypothesis corresponds to the second law of motion, as formulated two decades later by Newton, and its geometrical implementation constitutes the cornerstone of Newton's Principia. Hooke's diagram represents the first known accurate graphical evaluation of an orbit in a central field of force, and it gives evidence that he demonstrated that his resulting discrete orbit is an approximate ellipse centered at the origin of the field of force. A comparable calculation to obtain orbits for an inverse square force, which Hooke had conjectured to be the gravitational force, has not been found among his unpublished papers. Such a calculation is carried out here numerically with the Newton-Hooke geometrical construction. It is shown that for orbits of comparable or larger eccentricity than Hooke's example, a graphical approach runs into convergence difficulties due to the singularity of the gravitational force at the origin. This may help resolve the long-standing mystery why Hooke never published his controversial claim that he had demonstrated that an attractive force, which is ``...in a duplicate proportion to the Distance from the Center Reciprocall...'' implies elliptic orbits.

  10. Three Temperate Neptunes Orbiting Nearby Stars

    Science.gov (United States)

    Fulton, Benjamin J.; Howard, Andrew W.; Weiss, Lauren M.; Sinukoff, Evan; Petigura, Erik A.; Isaacson, Howard; Hirsch, Lea; Marcy, Geoffrey W.; Henry, Gregory W.; Grunblatt, Samuel K.; Huber, Daniel; von Braun, Kaspar; Boyajian, Tabetha S.; Kane, Stephen R.; Wittrock, Justin; Horch, Elliott P.; Ciardi, David R.; Howell, Steve B.; Wright, Jason T.; Ford, Eric B.

    2016-10-01

    We present the discovery of three modestly irradiated, roughly Neptune-mass planets orbiting three nearby Solar-type stars. HD 42618 b has a minimum mass of 15.4 ± 2.4 {M}\\oplus , a semimajor axis of 0.55 au, an equilibrium temperature of 337 K, and is the first planet discovered to orbit the solar analogue host star, HD 42618. We also discover new planets orbiting the known exoplanet host stars HD 164922 and HD 143761 (ρ CrB). The new planet orbiting HD 164922 has a minimum mass of 12.9 ± 1.6 {M}\\oplus and orbits interior to the previously known Jovian mass planet orbiting at 2.1 au. HD 164922 c has a semimajor axis of 0.34 au and an equilibrium temperature of 418 K. HD 143761 c orbits with a semimajor axis of 0.44 au, has a minimum mass of 25 ± 2 {M}\\oplus , and is the warmest of the three new planets with an equilibrium temperature of 445 K. It orbits exterior to the previously known warm Jupiter in the system. A transit search using space-based CoRoT data and ground-based photometry from the Automated Photometric Telescopes (APTs) at Fairborn Observatory failed to detect any transits, but the precise, high-cadence APT photometry helped to disentangle planetary-reflex motion from stellar activity. These planets were discovered as part of an ongoing radial velocity survey of bright, nearby, chromospherically inactive stars using the Automated Planet Finder (APF) telescope at Lick Observatory. The high-cadence APF data combined with nearly two decades of radial velocity data from Keck Observatory and gives unprecedented sensitivity to both short-period low-mass, and long-period intermediate-mass planets. Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology. Keck time was granted for this project by the University of Hawai‘i, the University of California, and NASA.

  11. Orbital angular momentum in the nucleons

    CERN Document Server

    Lorcé, Cédric

    2014-01-01

    In the last decade, it has been realized that the orbital angular momentum of partons inside the nucleon plays a major role. It contributes significantly to nucleon properties and is at the origin of many asymmetries observed in spin physics. It is therefore of paramount importance to determine this quantity if we want to understand the nucleon internal structure and experimental observables. This triggered numerous discussions and controversies about the proper definition of orbital angular momentum and its extraction from experimental data. We summarize the present situation and discuss recent developments in this field.

  12. Apparent Reversal of Molecular Orbitals Reveals Entanglement

    Science.gov (United States)

    Yu, Ping; Kocić, Nemanja; Repp, Jascha; Siegert, Benjamin; Donarini, Andrea

    2017-08-01

    The frontier orbital sequence of individual dicyanovinyl-substituted oligothiophene molecules is studied by means of scanning tunneling microscopy. On NaCl /Cu (111 ) , the molecules are neutral, and the two lowest unoccupied molecular states are observed in the expected order of increasing energy. On NaCl /Cu (311 ) , where the molecules are negatively charged, the sequence of two observed molecular orbitals is reversed, such that the one with one more nodal plane appears lower in energy. These experimental results, in open contradiction with a single-particle interpretation, are explained by a many-body theory predicting a strongly entangled doubly charged ground state.

  13. Orbital Metastasis of Multiple Myeloma: Case Report

    Directory of Open Access Journals (Sweden)

    Mustafa Vatansever

    2016-06-01

    Full Text Available A 68-year-old woman with a history of multiple myeloma presented to the clinic with pain and vision loss in her right eye. Proptosis was observed in her right eye and eye movements were restricted in all directions. Best corrected visual acuity was 3/10 in her right eye. On biomicroscopic examination, hyperemia and subconjunctival hemorrhage were present. Fundus examination of the right eye revealed optic disc edema and choroidal folds. In magnetic resonance imaging two orbital masses were detected. Based on the patient’s history and ocular examination, we evaluated the masses as orbital metastasis of multiple myeloma. Palliative radiotherapy was recommended.

  14. Japanese Venus Climate Orbiter in 2010

    Science.gov (United States)

    Nakamura, M.; Ishii, N.; Satoh, T.; Abe, T.; Imamura, T.; Suzuki, M.; Ueno, M.

    2008-12-01

    Venus Climate Orbiter (VCO"FProject Code Planet-C) is the first Japanese Venus orbiter to be launched in 2010. It aims at studying the atmospheric dynamics of Venus. In this talk we will report its engineering aspect to meet its science purposes, and also present the present status of the VCO development. We have finished the Proto-Model integration test of major components of VCO in December 2007. In March 2008, we finished the CDR for the phase-up (to Phase D). The flight model development will be finalized by 2009 and the final integration test will be done during whole 2009.

  15. Spin and orbital moments in actinide compounds

    DEFF Research Database (Denmark)

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

    1991-01-01

    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......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...

  16. SELENE: The Moon-Orbiting Observatory Mission

    Science.gov (United States)

    Mizutani, H.; Kato, M.; Sasaki, S.; Iijima, Y.; Tanaka, K.; Takizawa, Y.

    The Moon-orbiting SELENE (Selenological and Engineering Explorer) mission is prepared in Japan for lunar science and technology development. The launch target has been changed from 2005 to 2006 because of the launch failure of H2A rocket in 2003. The spacecraft consists of a main orbiting satellite at about 100 km altitude in the polar orbit and two sub-satellites in the elliptical orbits. The scientific objectives of the mission are; 1) study of the origin and evolution of the Moon, 2) in-situ measurement of the lunar environment, and 3) observation of the solar-terrestrial plasma environment. SELENE carries the instruments for scientific investigation, including mapping of lunar topography and surface composition, measurement of the gravity and magnetic fields, and observation of lunar and solar-terrestrial plasma environment. The total mass of scientific payload is about 300 kg. The mission period will be 1 year. If extra fuel is available, the mission will be extended in a lower orbit around 50 km. The elemental abundances are measured by x-ray and gamma-ray spectrometers. Alpha particles from the radon gas and polonium are detected by an alpha particle spectrometer. The mineralogical abundance is characterized by a multi-band imager. The mineralogical composition is identified by a spectral profiler which is a continuous spectral analyzer. The surface topographic data are obtained by a high resolution terrain camera and a laser altimeter. The inside structure up to 5 km below the lunar surface is observed by the radar sounder experiment using a 5 MHz radio wave. A magnetometer and an electron reflectometer provides data on the lunar surface magnetic field. Doppler tracking of the orbiter via the sub-satellite when the orbiter is in the far side is used to determine the gravity field of the far side. Radio sources on the two sub-satellites are used to conduct differential VLBI observation from the ground stations. The lunar environment of high energy particles

  17. Local orbitals in electron scattering calculations*

    Science.gov (United States)

    Winstead, Carl L.; McKoy, Vincent

    2016-05-01

    We examine the use of local orbitals to improve the scaling of calculations that incorporate target polarization in a description of low-energy electron-molecule scattering. After discussing the improved scaling that results, we consider the results of a test calculation that treats scattering from a two-molecule system using both local and delocalized orbitals. Initial results are promising. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

  18. Vertical orbital dystopia: definition, classification and treatment.

    Science.gov (United States)

    Wolfe, S A; Sassani, R

    1995-01-01

    Correction of vertical orbital dystopia is an important component part of providing facial symmetry in a number of conditions of varied etiology having facial imbalance and asymmetry. The most important step is the initial one of making a proper diagnosis, since some conditions represent globe dystopia rather than true orbital dystopia, and can be treated by extracranial procedures. However, if an intracranial procedure is felt indicated, it adds to the safety rather than the complexity of the procedure, and one should not hesitate advocating this to the patient.

  19. LOP- LONG-TERM ORBIT PREDICTOR

    Science.gov (United States)

    Kwok, J. H.

    1994-01-01

    The Long-Term Orbit Predictor (LOP) trajectory propagation program is a useful tool in lifetime analysis of orbiting spacecraft. LOP is suitable for studying planetary orbit missions with reconnaissance (flyby) and exploratory (mapping) trajectories. Sample data is included for a geosynchronous station drift cycle study, a Venus radar mapping strategy, a frozen orbit about Mars, and a repeat ground trace orbit. LOP uses the variation-of-parameters method in formulating the equations of motion. Terms involving the mean anomaly are removed from numerical integrations so that large step sizes, on the order of days, are possible. Consequently, LOP executes much faster than programs based on Cowell's method, such as the companion program ASAP (the Artificial Satellite Analysis Program, NPO-17522, also available through COSMIC). The program uses a force model with a gravity field of up to 21 by 21, lunisolar perturbation, drag, and solar radiation pressure. The input includes classical orbital elements (either mean or oscillating), orbital elements of the sun relative to the planet, reference time and dates, drag coefficients, gravitational constants, planet radius, rotation rate. The printed output contains the classical elements for each time step or event step, and additional orbital data such as true anomaly, eccentric anomaly, latitude, longitude, periapsis altitude, and the rate of change per day of certain elements. Selected output is additionally written to a plot file for postprocessing by the user. LOP is written in FORTRAN 77 for batch execution on IBM PC compatibles running MS-DOS with a minimum of 256K RAM. Recompiling the source requires the Lahey F77 v2.2 compiler. The LOP package includes examples that use LOTUS 1-2-3 for graphical displays, but any graphics software package should be able to handle the ASCII plot file. The program is available on two 5.25 inch 360K MS-DOS format diskettes. The program was written in 1986 and last updated in 1989. LOP is

  20. Shaft Center Orbit in Dynamically Loaded Bearings

    DEFF Research Database (Denmark)

    Klit, Peder

    The aim of this work is to demonstrate how to utilize the bearings damping coefficients to estimate the orbit for a dynamically loaded journal bearing. The classical method for this analysis was developed by Booker in 1965 and described further in 1972. Several authors have refined this method over...... Jorgen W. Lund pointed out in lecture notes that the dynamic damping coefficients of the bearing could be used to find the shaft orbit for dynamically loaded bearings. For simplicity the "Short-Width-Journal-Bearing Theory" is used as a basis for finding the damping coefficients in this work...

  1. Lenz micropthalmia syndrome with associated orbital cysts.

    Science.gov (United States)

    Rafailov, Leon; Dattilo, Michael; Shinder, Roman

    2014-01-01

    An 8-year-old boy presented for oculoplastic evaluation of bilateral microphthalmia. He had multiple other congenital anomalies, including microcephaly, wide-spaced teeth, sloping shoulders, protruding ears, syndactyly, a posterior urethral valve, cystic dysplasia of the kidneys, and a bicuspid aortic valve. Taken together, these findings supported the diagnosis of Lenz microphthalmia syndrome. CT of the orbits revealed bilateral microphthalmic globes with associated colobomatous cysts. To the authors' knowledge, this is the first reported case of Lenz microphthalmia syndrome with associated orbital cysts.

  2. Measuring orbital interaction using quantum information theory

    Energy Technology Data Exchange (ETDEWEB)

    Rissler, Joerg [Fachbereich Physik, Philipps-Universitaet Marburg, AG Vielteilchentheorie, Renthof 6, D-35032 Marburg (Germany)], E-mail: rissler@staff.uni-marburg.de; Noack, Reinhard M. [Fachbereich Physik, Philipps-Universitaet Marburg, AG Vielteilchentheorie, Renthof 6, D-35032 Marburg (Germany); White, Steven R. [Department of Physics and Astronomy, University of California, Irvine, CA 92697-4575 (United States)

    2006-04-21

    Quantum information theory gives rise to a straightforward definition of the interaction of electrons I {sub p,q} in two orbitals p,q for a given many-body wave function. A convenient way to calculate the von Neumann entropies needed is presented in this work, and the orbital interaction I {sub p,q} is successfully tested for different types of chemical bonds. As an example of an application of I {sub p,q} beyond the interpretation of wave functions, I {sub p,q} is then used to investigate the ordering problem in the density-matrix renormalization group.

  3. Two-Centered Magical Charge Orbits

    CERN Document Server

    Andrianopoli, Laura; Ferrara, Sergio; Marrani, Alessio; Trigiante, Mario

    2011-01-01

    We determine the two-centered generic charge orbits of magical N = 2 and maximal N = 8 supergravity theories in four dimensions. These orbits are classified by seven U-duality invariant polynomials, which group together into four invariants under the horizontal symmetry group SL(2,R). These latter are expected to disentangle different physical properties of the two-centered black-hole system. The invariant with the lowest degree in charges is the symplectic product (Q1,Q2), known to control the mutual non-locality of the two centers.

  4. Hypoelliptic Laplacian and Orbital Integrals (AM-177)

    CERN Document Server

    Bismut, Jean-Michel

    2012-01-01

    This book uses the hypoelliptic Laplacian to evaluate semisimple orbital integrals in a formalism that unifies index theory and the trace formula. The hypoelliptic Laplacian is a family of operators that is supposed to interpolate between the ordinary Laplacian and the geodesic flow. It is essentially the weighted sum of a harmonic oscillator along the fiber of the tangent bundle, and of the generator of the geodesic flow. In this book, semisimple orbital integrals associated with the heat kernel of the Casimir operator are shown to be invariant under a suitable hypoelliptic deformation, whic

  5. 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....

  6. Orbiting droplets on a vibrated bath

    Science.gov (United States)

    Sampara, Naresh; Burger, Loic; Gilet, Tristan; Microfluidics, university of liege Team

    2015-11-01

    A millimeter-sized oil droplet can bounce on a vertically vibrated liquid bath for unlimited time. It may couple to the surface wave it emits; leading to horizontal self-propulsion called walking. When several walkers coexist close to one another, they either repel or attract each other, in response to the superposition of the waves they generate. Attraction leads to various bound states, including droplets that orbit around each other. We have experimentally investigated the variety of quantized orbital motions exhibited by two, three and more identical walkers, as a function of forcing acceleration. Each motion is quantified in terms of droplet and wave energy.

  7. Meteorites from recent amor-type orbits

    Science.gov (United States)

    Benoit, P. H.; Sears, D. W. G.

    1993-01-01

    We report here the discovery of a recent meteorite shower in Antarctica, the members of which have very high natural thermoluminescence levels. It is apparent from these data that the shower has been on Earth only a short time (approximately 1000 years) and the meteorite probably came to Earth through rapid (less than 10 exp 5 years) evolution from an orbit with perihelion greater than 1.1 AU, similar to Amor asteroids. Only a very small number of meteorites, including a few modern falls, appear to have had similar orbital histories.

  8. 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.

  9. Problem of algorithm in precision orbit determination

    Institute of Scientific and Technical Information of China (English)

    刘林; 张强; 廖新浩

    1999-01-01

    In orbit determination, the precision ephemeris and state transition matrix are usually obtained by solving two groups of ordinary differential equations with numerical integration method due to the complexity of the force models. A kind of simplified analytical method to compute the state transition matrix is given. The method is not only very efficient for the case where the orbit arc is not too long, but also can avoid the integration of two groups of ordinary differential equations at the same time. Some practical test examples also show the efficiency of the method.

  10. 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 $etageq 1$.

  11. 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.

  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. The one-electron description of excited states: Natural excitation orbitals of density matrix theory and Kohn-Sham orbitals of density functional theory as ideal orbitals

    Science.gov (United States)

    van Meer, R.; Gritsenko, O. V.; Baerends, E. J.

    2015-10-01

    Linear response density matrix functional theory has been shown to solve the main problems of time-dependent density functional theory (deficient in case of double, charge transfer and bond breaking excitations). However, the natural orbitals preclude the description of excitations as (approximately) simple orbital-to-orbital transitions: many weakly occupied 'virtual' natural orbitals are required to describe the excitations. Kohn-Sham orbitals on the other hand afford for many excitations such a simple orbital description. In this communication we show that a transformation of the set of weakly occupied NOs can be defined such that the resulting natural excitation orbitals (NEOs) restore the single orbital transition structure for excitations generated by the linear response DMFT formalism.

  14. Orbitals from local RDMFT: Are they Kohn-Sham or Natural Orbitals?

    CERN Document Server

    Theophilou, Iris; Gidopoulos, Nikitas I; Rubio, Angel; Helbig, Nicole

    2015-01-01

    Recently, an approximation was introduced in reduced density matrix functional theory (RDMFT), called local-RDMFT, where functionals of the one-body reduced density matrix (1-RDM) are minimized under the additional condition that the optimal orbitals satisfy a single electron Schr\\"odinger equation with a local potential. In the present work, we assess the impact of this additional condition on the optimal orbitals. In particular we compare orbitals obtained by local-RDMFT with those obtained with the full minimization (without the extra condition) by comparing them with the exact NOs and orbitals from a density functional calculation using the local density approximation (LDA). We find that the orbitals from local-RMDFT are very close to LDA orbitals, contrary to those of the full minimization that resemble the exact NOs. Since local RDMFT preserves the good quality of the description of strong static correlation, this finding opens the way to a mixed density/density matrix scheme, where Kohn-Sham orbitals o...

  15. Orbital Reconstruction in Neuroectodermal Tumor of the Orbit: Multimodal Treatment Approach.

    Science.gov (United States)

    Cantini A, Jorge Ernesto; López, Diana M Díaz; Florez, Esteban Francisco Hernandez

    2017-04-11

    Primitive neuroectodermal tumors of peripheral origin are very rare, and orbital neuroectodermal tumors are even more uncommon. Only 25 patients with primary orbital involvement in the pediatric age group have been reported. In this article, the authors describe their experience in the multimodality treatment approach to treat neuroectodermal tumor of the orbit. The authors also present a male patient 3-year old presenting with a neuroectodermal tumor of the right orbit causing rapidly progressive proptosis. The patient underwent an upper and lateral orbital marginotomy. The entire bone defect was reconstructed with a bone graft, allowing for the reconstruction of the floor and the lateral wall of the middle cranial fossa, the floor of the anterior cranial fossa, the upper and lateral orbital frame, and the right zygomatic bone. Over a period of 16 months, the patient was subjected to chemotherapy. In the postoperative period, a favorable evolution of the disease was observed, with growth in the reconstructed structures, good projection of the orbit and the eyeball, and stable results without tumor recurrence. The authors present the clinical analysis, surgical management, as well as the chemotherapy treatment established, with follow-ups at 1 and 2 and a half years. This experience shows the effectiveness of multimodality therapy in the treatment of rare tumors of difficult handling.

  16. Orbitals from local RDMFT: Are they Kohn-Sham or natural orbitals?

    Energy Technology Data Exchange (ETDEWEB)

    Theophilou, Iris; Helbig, Nicole [Peter-Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich (Germany); Lathiotakis, Nektarios N. [Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Vass. Constantinou 48, GR-11635 Athens (Greece); Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Saale) (Germany); Gidopoulos, Nikitas I. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Rubio, Angel [Max Planck Institute for the Structure and Dynamics of Matter and Center for Free-Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg (Germany); Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Dpto. Física de Materiales, Universidad del País Vasco, CFM CSIC-UPV/EHU-MPC and DIPC, Av. Tolosa 72, E-20018 San Sebastián (Spain)

    2015-08-07

    Recently, an approximate theoretical framework was introduced, called local reduced density matrix functional theory (local-RDMFT), where functionals of the one-body reduced density matrix (1-RDM) are minimized under the additional condition that the optimal orbitals satisfy a single electron Schrödinger equation with a local potential. In the present work, we focus on the character of these optimal orbitals. In particular, we compare orbitals obtained by local-RDMFT with those obtained with the full minimization (without the extra condition) by contrasting them against the exact NOs and orbitals from a density functional calculation using the local density approximation (LDA). We find that the orbitals from local-RMDFT are very close to LDA orbitals, contrary to those of the full minimization that resemble the exact NOs. Since local RDMFT preserves the good quality of the description of strong static correlation, this finding opens the way to a mixed density/density matrix scheme, where Kohn-Sham orbitals obtain fractional occupations from a minimization of the occupation numbers using 1-RDM functionals. This will allow for a description of strong correlation at a cost only minimally higher than a density functional calculation.

  17. Precise orbit determination and rapid orbit recovery supported by time synchronization

    Science.gov (United States)

    Guo, Rui; Zhou, JianHua; Hu, XiaoGong; Liu, Li; Tang, Bo; Li, XiaoJie; Wu, Shan

    2015-06-01

    In order to maintain optimal signal coverage, GNSS satellites have to experience orbital maneuvers. For China's COMPASS system, precise orbit determination (POD) as well as rapid orbit recovery after maneuvers contribute to the overall Positioning, Navigation and Timing (PNT) service performance in terms of accuracy and availability. However, strong statistical correlations between clock offsets and the radial component of a satellite's positions require long data arcs for POD to converge. We propose here a new strategy which relies on time synchronization between ground tracking stations and in-orbit satellites. By fixing satellite clock offsets measured by the satellite station two-way synchronization (SSTS) systems and receiver clock offsets, POD and orbital recovery performance can be improved significantly. Using the Satellite Laser Ranging (SLR) as orbital accuracy evaluation, we find the 4-hr recovered orbit achieves about 0.71 m residual root mean square (RMS) error of fit SLR data, the recovery time is improved from 24-hr to 4-hr compared with the conventional POD without time synchronization support. In addition, SLR evaluation shows that for 1-hr prediction, about 1.47 m accuracy is achieved with the new proposed POD strategy.

  18. Interacting Binaries with Eccentric Orbits. Secular Orbital Evolution Due To Conservative Mass Transfer

    CERN Document Server

    Sepinsky, J F; Kalogera, V; Rasio, F A

    2007-01-01

    We investigate the secular evolution of the orbital semi-major axis and eccentricity due to mass transfer in eccentric binaries, assuming conservation of total system mass and orbital angular momentum. Assuming a delta function mass transfer rate centered at periastron, we find rates of secular change of the orbital semi-major axis and eccentricity which are linearly proportional to the magnitude of the mass transfer rate at periastron. The rates can be positive as well as negative, so that the semi-major axis and eccentricity can increase as well as decrease in time. Adopting a delta-function mass-transfer rate of $10^{-9} M_\\sun {\\rm yr}^{-1}$ at periastron yields orbital evolution timescales ranging from a few Myr to a Hubble time or more, depending on the binary mass ratio and orbital eccentricity. Comparison with orbital evolution timescales due to dissipative tides furthermore shows that tides cannot, in all cases, circularize the orbit rapidly enough to justify the often adopted assumption of instantan...

  19. Magnetic and orbital ordering in the iron-based superconductors. Role of spin-orbit coupling

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Felix; Eremin, Ilya [Institut fuer Theoretische Physik III, Ruhr-Universitaet Bochum (Germany); Knolle, Johannes [Max Planck Institute for the Physics of Complex Systems, Dresden (Germany); Fernandes, Rafael [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN (United States)

    2015-07-01

    We analyze the magnetic ordering in the iron-based superconductors in presence of spin-orbit coupling. Based on several tight-binding parametrizations of the 3d electron states we show how the spin-orbit coupling introduces the anisotropy of the magnetization of the striped antiferromagnetic state by lifting the degeneracy of all three components of the magnetization m{sub x}, m{sub y} and m{sub z}. The orientation of the magnetic moment is determined by the contribution of the xy, xz, and yz orbitals to the electronic states near the Fermi level of the electron and hole bands and is determined by the electron filling. We find that within an itinerant approach the magnetic ordering is most favorable along the wavevector of the striped AF state. This appears to be a natural consequence of the spin-orbit coupling in the striped AF state where the ferro-orbital order of the xz and yz orbitals is only a consequence of the striped AF order. We further analyze the role of spin-orbit coupling for the C{sub 4} magnetic structure where SDW order parameters with both wavevectors, Q{sub x} = (π,0) and Q{sub y} = (0,π), coexist.

  20. A universal on-orbit servicing system used in the geostationary orbit

    Science.gov (United States)

    Xu, Wenfu; Liang, Bin; Li, Bing; Xu, Yangsheng

    2011-07-01

    The geostationary orbit (GEO), a unique satellite orbit of the human beings, is a very precious orbit resource. However, the continuous increasing of GEO debris makes the GEO orbit more and more crowded. Moreover, the failures of GEO spacecrafts will result in large economic cost and other bad impacts. In this paper, we proposed a space robotic servicing system, and developed key pose (position and orientation) measurement and control algorithm. Firstly, the necessity of orbit service in GEO was analyzed. Then, a servicing concept for GEO non-cooperative targets was presented and a universal space robotic servicing system was designed. The system has a 2-DOF docking mechanism, a 7-DOF redundant manipulator and a set of stereo vision, in addition to the traditional subsystems of a spacecraft. This system can serve most existing satellites in GEO, not requiring specially designed objects for grappling and measuring on the target. The servicing contents include: (a) visual inspecting; (b) target tracking, approaching and docking; (c) ORUs (Orbital Replacement Units) replacement; (d) Malfunctioned mechanism deploying; (e) satellites life extension by taking over its control, or re-orbiting the abandoned satellites. As an example, the servicing mission of a malfunctioned GEO satellite with three severe mechanical failures was designed and simulated. The results showed the validity and flexibility of the proposed system.

  1. 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.

  2. Experiments in orbit determination using numerical methods

    NARCIS (Netherlands)

    Traas, C.R.

    1985-01-01

    The dynamics of the observed object is written as a system of integral equations. This system is solved numerically by representing the components of the force function as linear combinations of B-splines and by applying the multigrid technique. In an outer loop the orbit determination problem is

  3. Orbits of Ten Visual Binary Stars

    Institute of Scientific and Technical Information of China (English)

    B.Novakovi(c)

    2007-01-01

    We present the orbits of ten visual binary stars:WDS 01015+6922.WDS 01424-0645,WDS 01461+6349,WDS 04374-0951,WDS 04478+5318,WDS 05255-0033,WDS 05491+6248,WDS 06404+4058,WDS 07479-1212,and WDS 18384+0850.We have also determined their masses,dynamical parallaxes and ephemerides.

  4. Cancer of the orbit and adnexa.

    Science.gov (United States)

    Schwarcz, Robert M; Coupland, Sarah E; Finger, Paul T

    2013-04-01

    The diagnosis and treatment of orbital and periorbital malignancies are challenging. These tumors can result in blindness, death, and significant cosmetic deformities. Herein, we present the most common ocular malignancies and a systematic approach to diagnosis. Further, we integrate the seventh edition American Joint Committee on Cancer staging system, biomarkers, and multidisciplinary approaches to treatment.

  5. Periodic orbits near a bifurcating slow manifold

    DEFF Research Database (Denmark)

    Kristiansen, Kristian Uldall

    2015-01-01

    This paper studies a class of $1\\frac12$-degree-of-freedom Hamiltonian systems with a slowly varying phase that unfolds a Hamiltonian pitchfork bifurcation. The main result of the paper is that there exists an order of $\\ln^2\\epsilon^{-1}$-many periodic orbits that all stay within an $\\mathcal O...

  6. 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.

  7. Accelerometers for Precise GNSS Orbit Determination

    Science.gov (United States)

    Hugentobler, Urs; Schlicht, Anja

    2016-07-01

    The solar radiation pressure is the largest non-gravitational acceleration on GNSS satellites limiting the accuracy of precise orbit models. Other non-gravitational accelerations may be thrusts for station keeping maneuvers. Accelerometers measure the motion of a test mass that is shielded against satellite surface forces with respect to a cage that is rigidly connected to the satellite. They can thus be used to measure these difficult-to-model non-gravitational accelerations. Accelerometers however typically show correlated noise as well as a drift of the scaling factors converting measured voltages to accelerations. The scaling thus needs to be regularly calibrated. The presented study is based on several simulated scenarios including orbit determination of accelerometer-equipped Galileo satellites. It shall evaluate different options on how to accommodate accelerometer measurements in the orbit integrator, indicate to what extent currently available accelerometers can be used to improve the modeling of non-gravitational accelerations on GNSS satellites for precise orbit determination, and assess the necessary requirements for an accelerometer that can serve this purpose.

  8. Spin-orbit correlations in the nucleon

    CERN Document Server

    Lorcé, Cédric

    2014-01-01

    We investigate the correlations between the quark spin and orbital angular momentum inside the nucleon. Similarly to the Ji relation, we show that these correlations can be expressed in terms of specific moments of measurable parton distributions. This provides a whole new piece of information about the partonic structure of the nucleon.

  9. Wigner Functions and Quark Orbital Angular Momentum

    Directory of Open Access Journals (Sweden)

    Mukherjee Asmita

    2015-01-01

    Full Text Available Wigner distributions contain combined position and momentum space information of the quark distributions and are related to both generalized parton distributions (GPDs and transverse momentum dependent parton distributions (TMDs. We report on a recent model calculation of the Wigner distributions for the quark and their relation to the orbital angular momentum.

  10. The Homoclinic Orbit Solution for Functional Equation

    Institute of Scientific and Technical Information of China (English)

    LIU Shi-Da; FU Zun-Tao; LIU Shi-Kuo; REN Kui

    2002-01-01

    In this paper, some examples, such as iterated functional systems, scaling equation of wavelet transform,and invariant measure system, are used to show that the homoclinic orbit solutions exist in the functional equations too.And the solitary wave exists in generalized dynamical systems and functional systems.

  11. 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 bring...

  12. Congenital orbital sudoriferous cyst: radiological findings

    Energy Technology Data Exchange (ETDEWEB)

    Haider, Ehsaan; Gill, Dan [McGill University, Department of Radiology, Montreal (Canada); Saigal, Gaurav [University of Miami, Department of Radiology, Jackson Memorial Hospital, Miami, FL (United States); Brown, Erik [McGill University, Montreal (Canada); Daniel, Sam [McGill University, Department of Otolarnygology, Montreal Children' s Hospital, Montreal (Canada)

    2005-11-01

    We report an extremely unusual case of a 4-month-old boy who presented with a sudoriferous gland cyst of the orbit. Congenital sudoriferous cyst is extremely rare in both the adult and pediatric populations. The CT and MRI findings are presented and the pertinent literature reviewed. (orig.)

  13. Utilizing Astrometric Orbits to Obtain Coronagraphic Images

    CERN Document Server

    Davidson, John M

    2010-01-01

    We present an approach for utilizing astrometric orbit information to improve the yield of planetary images and spectra from a follow-on direct detection mission. This approach is based on the notion-strictly hypothetical-that if a particular star could be observed continuously, the instrument would in time observe all portions of the habitable zone so that no planet residing therein could be missed. This strategy could not be implemented in any realistic mission scenario. But if an exoplanet's orbit is known from astrometric observation, then it may be possible to plan and schedule a sequence of imaging observations that is the equivalent of continuous observation. A series of images-optimally spaced in time-could be recorded to examine contiguous segments of the orbit. In time, all segments would be examined, leading to the inevitable detection of the planet. In this paper, we show how astrometric orbit information can be used to construct such a sequence. Using stars from astrometric and imaging target lis...

  14. Neptune's Orbital Migration Was Grainy, Not Smooth

    CERN Document Server

    Nesvorny, David

    2016-01-01

    The Kuiper belt is a population of icy bodies beyond the orbit of Neptune. The complex orbital structure of the Kuiper belt, including several categories of objects inside and outside of resonances with Neptune, emerged as a result of Neptune's migration into an outer planetesimal disk. An outstanding problem with the existing migration models is that they invariably predict excessively large resonant populations, while observations show that the non-resonant orbits are in fact common (e.g., the main belt population is 2-4 times larger than Plutinos in the 3:2 resonance). Here we show that this problem can resolved if it is assumed that Neptune's migration was grainy, as expected from scattering encounters of Neptune with massive planetesimals. The grainy migration acts to destabilize resonant bodies with large libration amplitudes, a fraction of which ends up on stable non-resonant orbits. Thus, the non-resonant--to--resonant ratio obtained with the grainy migration is higher, up to ~10 times higher for the ...

  15. Orbit Connections in a Parabolic Equation.

    Science.gov (United States)

    1983-04-01

    Departamento de Matematica , 13560, Slo Carlos, S.P. Brasil. This research has been supported in part by CAPES-qoordena~io de Aperfeiqoamento de Pessoal...de Nivel Superior , Brasilia, D.F., Brasil under contract Proc. #3056/78. 1k ORBIT CONNECTIONS IN A PARABOLIC EQUATION by Jack K. Hale and Arnaldo S

  16. Accelerated rotation with orbital angular momentum modes

    CSIR Research Space (South Africa)

    Schulze, C

    2015-04-01

    Full Text Available A 91, 043821 (2015) Accelerated rotation with orbital angular momentum modes Christian Schulze, Filippus S. Roux, Angela Dudley, Ronald Rop, Michael Duparr´e, and Andrew Forbes Abstract: We introduce a class of light field that angularly...

  17. Imaging of the midfacial and orbital trauma.

    Science.gov (United States)

    Wikner, Johannes; Riecke, Björn; Gröbe, Alexander; Heiland, Max; Hanken, Henning

    2014-10-01

    The severity of midfacial and orbital injuries depends on the one hand on cause, force vector, load point, or area and on the other hand on the bony and soft tissue resistance as well as individual anatomy. These variables result in a variety of possible injuries of the midfacial and orbital complex. The time critical choice of an adequate imaging modality of these injuries is influenced by the possible severity of concomitant injuries. Besides the confirmation of a clinical diagnosis, the need for high-resolution three-dimensional imaging for preoperative planning of facial reconstruction using intraoperative navigation has become more and more important in the past years. To achieve optimal functional and esthetic outcomes, the anatomical complexity of the midface has to be addressed and the adequate imaging modality has to be chosen keeping the upcoming surgical treatment in mind. The current imaging modalities for midfacial and orbital trauma are presented and critically evaluated depending on the indications. Furthermore, new strategies to support surgeons in achieving best possible midfacial reconstructions are discussed. An algorithm to choose the adequate imaging modality in midfacial and orbital traumatology is provided.

  18. Nuclear-Thermal Rocket Orbits Mars

    Science.gov (United States)

    1960-01-01

    Originally investigated in the 1960's by Marshall Space Flight Center plarners as part of the Nuclear Energy for Rocket Vehicle Applications (NERVA) program, nuclear-thermal rocket propulsion has been more recently considered in spacecraft designs for interplanetary human exploration. This artist's concept illustrates a nuclear-thermal rocket with an aerobrake disk as it orbits Mars.

  19. Orbits for eight Hipparcos double stars

    Energy Technology Data Exchange (ETDEWEB)

    Cvetković, Z.; Pavlović, R.; Ninković, S., E-mail: zcvetkovic@aob.bg.ac.rs [Astronomical Observatory, Volgina 7, 11060 Belgrade 38 (Serbia)

    2014-03-01

    In this paper, we analyze new orbital elements and the quantities that follow from them for eight binaries: WDS 00101+3825 = HDS 23Da,Db, WDS 00321–1218 = HDS 71, WDS 04287+2613 = HDS 576, WDS 04389–1207 = HDS 599, WDS 16206+4535 = HDS 2309, WDS 17155+1052 = HDS 2440, WDS 22161–0705 = HDS 3158, and WDS 23167+3441 = HDS 3315. For seven of them, the orbital elements are calculated for the first time. Binaries, denoted as HDS, were discovered during the Hipparcos mission, and their first observational epoch is 1991.25, the same as the mean epoch of the Hipparcos catalog. We found all other measurements of these binaries in databases. They were obtained in the last 15 yr using the speckle interferometric technique. All studied pairs are close, and all measured separations are less than 0.''4. The resulting orbital periods fall within 26 and 80 yr. In addition to the orbital elements, we also give (O – C) residuals in θ and ρ, masses, dynamical parallaxes, absolute magnitudes, spectral types, and ephemerides for the next 5 yr.

  20. Orbits for Eight Hipparcos Double Stars

    Science.gov (United States)

    Cvetković, Z.; Pavlović, R.; Ninković, S.

    2014-03-01

    In this paper, we analyze new orbital elements and the quantities that follow from them for eight binaries: WDS 00101+3825 = HDS 23Da,Db, WDS 00321-1218 = HDS 71, WDS 04287+2613 = HDS 576, WDS 04389-1207 = HDS 599, WDS 16206+4535 = HDS 2309, WDS 17155+1052 = HDS 2440, WDS 22161-0705 = HDS 3158, and WDS 23167+3441 = HDS 3315. For seven of them, the orbital elements are calculated for the first time. Binaries, denoted as HDS, were discovered during the Hipparcos mission, and their first observational epoch is 1991.25, the same as the mean epoch of the Hipparcos catalog. We found all other measurements of these binaries in databases. They were obtained in the last 15 yr using the speckle interferometric technique. All studied pairs are close, and all measured separations are less than 0.''4. The resulting orbital periods fall within 26 and 80 yr. In addition to the orbital elements, we also give (O - C) residuals in θ and ρ, masses, dynamical parallaxes, absolute magnitudes, spectral types, and ephemerides for the next 5 yr.

  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. Transversal heteroclinic orbits in general degenerate cases

    Institute of Scientific and Technical Information of China (English)

    朱德明

    1996-01-01

    A geometrical method using the exponential dichotomy and the invariant manifold thoery is given to set up the criteria for the existence of transversal and tangential heterodinic orbits under the most general degenerate cases. Conclusions given here extend and contain the relevant known results.

  3. NGC 1300 Dynamics: III. Orbital analysis

    CERN Document Server

    Patsis, P A; Grosbol, P

    2010-01-01

    We present the orbital analysis of four response models, that succeed in reproducing morphological features of NGC 1300. Two of them assume a planar (2D) geometry with $\\Omega_p$=22 and 16 \\ksk respectively. The two others assume a cylindrical (thick) disc and rotate with the same pattern speeds as the 2D models. These response models reproduce most successfully main morphological features of NGC 1300 among a large number of models, as became evident in a previous study. Our main result is the discovery of three new dynamical mechanisms that can support structures in a barred-spiral grand design system. These mechanisms are presented in characteristic cases, where these dynamical phenomena take place. They refer firstly to the support of a strong bar, of ansae type, almost solely by chaotic orbits, then to the support of spirals by chaotic orbits that for a certain number of pat tern revolutions follow an n:1 (n=7,8) morphology, and finally to the support of spiral arms by a combination of orbits trapped arou...

  4. Cavernous Hemangioma of the Bony Orbit

    Institute of Scientific and Technical Information of China (English)

    Jianhua Yan; Yu Cai; Zhongyao Wu; Ji Han; Youjian Pang

    2005-01-01

    Purpose: To study the clinical features, diagnosis and management of intraosseous cavernous hemangioma of the orbit.Methods: Five cases of intraosseous cavernous hemangioma seen in our hospital from Jan 1, 1986 to Dec 31, 2000 were reviewed.Results: Among all five cases, two were male and three were female. The mean age was 47.6 years old, ranging from 39.0 to 55.0 years. The left orbit was affected in 4 cases and the right one in 1 case. The bony involvement occurred in frontal bone (two cases),zygomatic bone (two cases) and sphenoid bone (one case). A painless, slowly enlarging hard bony mass fixed to the bone with no pulsations was the main clinical sign. The x-ray and CT appearance of intraosseous cavernous hemangioma of the orbit were characteristic and usually diagnostic. The differential diagnosis of it included fibrous dysplasia,eosinophilic granuloma, multiple myeloma and metastatic carcinoma. Treatment is local removal of the bone containing the tumor.Conclusions: Intraosseous cavernous hemangioma is a rare tumor of the orbit and usually has good surgical result.

  5. 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...

  6. The Orbital Angular Momentum Sum Rule

    Science.gov (United States)

    Aslan, Fatma; Burkardt, Matthias

    2015-10-01

    As an alternative to the Ji sum rule for the quark angular momentum, a sum rule for the quark orbital angular momentum, based on a twist-3 generalized parton distribution, has been suggested. We study the validity of this sum rule in the context of scalar Yukawa interactions as well as in QED for an electron.

  7. Orbiter Auxiliary Power Unit Flight Support Plan

    Science.gov (United States)

    Guirl, Robert; Munroe, James; Scott, Walter

    1990-01-01

    This paper discussed the development of an integrated Orbiter Auxiliary Power Unit (APU) and Improved APU (IAPU) Flight Suuport Plan. The plan identifies hardware requirements for continued support of flight activities for the Space Shuttle Orbiter fleet. Each Orbiter vehicle has three APUs that provide power to the hydraulic system for flight control surface actuation, engine gimbaling, landing gear deployment, braking, and steering. The APUs contain hardware that has been found over the course of development and flight history to have operating time and on-vehicle exposure time limits. These APUs will be replaced by IAPUs with enhanced operating lives on a vehicle-by-vehicle basis during scheduled Orbiter modification periods. This Flight Support Plan is used by program management, engineering, logistics, contracts, and procurement groups to establish optimum use of available hardware and replacement quantities and delivery requirements for APUs until vehicle modifications and incorporation of IAPUs. Changes to the flight manifest and program delays are evaluated relative to their impact on hardware availability.

  8. Spacecraft Robustness to Orbital Debris: Guidelines & Recommendations

    Science.gov (United States)

    Heinrich, S.; Legloire, D.; Tromba, A.; Tholot, M.; Nold, O.

    2013-09-01

    The ever increasing number of orbital debris has already led the space community to implement guidelines and requirements for "cleaner" and "safer" space operations as non-debris generating missions and end of mission disposal in order to get preserved orbits rid of space junks. It is nowadays well-known that man-made orbital debris impacts are now a higher threat than natural micro-meteoroids and that recent events intentionally or accidentally generated so many new debris that may initiate a cascade chain effect known as "the Kessler Syndrome" potentially jeopardizing the useful orbits.The main recommendations on satellite design is to demonstrate an acceptable Probability of Non-Penetration (PNP) with regard to small population (risks with the introduction of new of probability and criticality classification scales. * Examples of design risks assessment with regard to the specific MMOD impact risks. * Lessons learnt on robustness survivability of systems (materials, shieldings, rules) coming from other industrial domains (automotive, military vehicles) * Guidelines and Recommendations implementable on satellite systems and mechanical architecture.

  9. Mesoscopic Rings with Spin-Orbit Interactions

    Science.gov (United States)

    Berche, Bertrand; Chatelain, Christophe; Medina, Ernesto

    2010-01-01

    A didactic description of charge and spin equilibrium currents on mesoscopic rings in the presence of spin-orbit interaction is presented. Emphasis is made on the non-trivial construction of the correct Hamiltonian in polar coordinates, the calculation of eigenvalues and eigenfunctions and the symmetries of the ground-state properties. Spin…

  10. THEMIS Orbits and Data at SPDF

    Science.gov (United States)

    Bilitza, D.; McGuire, R. E.; Candey, R. M.; Chimiak, R. A.; Harris, B. T.; Han, D. B.; Kovalick, T. J.; Johnson, R. C.; Leckner, H. A.; Angelopoulos, V.

    2007-12-01

    The Space Physics Data Facility (SPDF) within Goddard's Heliospheric Physics Laboratory has worked closely with the THEMIS team to adapt SPDF's orbit and data tools/services to the special needs of the THEMIS mission. We will explain and demonstrate these systems that now include Level-2 data from the THEMIS ground and space instruments and the latest orbits and orbit predictions. CDAWeb now serves current FluxGate Magnetometer (FGM), ElectroStatic Analyzer (ESA), Solid-State Telescope (SST), Electric Field Instrument (EFI) and Search Coil Magnetometer (SCM) data from all 5 THEMIS spacecraft and magnetometer data from 20+ THEMIS ground stations. CDAWeb displays include line plots and spectrograms and outputs are now also available in PDF and Postscript. The latest version of the 3-D interactive orbit viewer now includes the capability to follow the magnetic ground tracks of the THEMIS satellites and their relation to the THEMIS ground stations making it an excellent tool for the coordinated analysis of THEMIS space and ground data. The SSCWeb system allows complex queries involving magnetic conjunctions between satellites and between satellites and ground stations, and region occupancy. Several THEMIS-specific queries were set up and saved and are now available for easy (one click) usage. THEMIS is utilizing the Common Data Format (CDF) for its data products, a format developed and maintained by SPDF and the backbone of the CDAWeb system. A number of CDF routines were customized for most efficient use by the THEMIS team.

  11. Applying KAM Theory to Highly Eccentric Orbits

    Science.gov (United States)

    2014-03-27

    Motivation In 2009, the Iridium 33 and Kosmos 2251 satellite collided in outer space. This was the first unintentional collision at high speeds between two...artificial satellites in the earth’s orbit [1]. Iridium 33 was an operational satellite, and Kosmos was out of service for 13 years. Besides completely

  12. Closed orbit response to quadrupole strength variation

    Energy Technology Data Exchange (ETDEWEB)

    Wolski, Andrzej; Zimmermann, Frank

    2004-01-20

    We derive two formulae relating the variation in closed orbit in a storage ring to variations in quadrupole strength, neglecting nonlinear and dispersive effects. These formulae correct results previously reported [1,2,3]. We compare the results of the formulae applied to the ATF with simulations using MAD, and consider their application to beam-based alignment.

  13. The Homoclinic Orbit Solution for Functional Equation

    Institute of Scientific and Technical Information of China (English)

    LIUShi-Da; FUZun-Tao; 等

    2002-01-01

    In this paper,some examples,such as iterated functional systems,scaling equation of wavelet transform,and invariant measure system,are used to show that the homoclinic orbit solutions exist in the functional equations too.And the solitary wave exists in generalized dynamical systems and functional systems.

  14. Upper atmospheric rotation rate from orbit analysis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The rotation speed Λ of the upper atmosphere,mainly at heights of 180-360 km,was evaluated from the changes in orbital inclinations of GFZ. The results indicate that the value of Λ(in rev/d) decreases from 1.2 at 360 km to 0.9 at 180 km.

  15. 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.

  16. Earth orbital teleoperator visual system evaluation program

    Science.gov (United States)

    Shields, N. L., Jr.; Kirkpatrick, M., III; Frederick, P. N.; Malone, T. B.

    1975-01-01

    Empirical tests of range estimation accuracy and resolution, via television, under monoptic and steroptic viewing conditions are discussed. Test data are used to derive man machine interface requirements and make design decisions for an orbital remote manipulator system. Remote manipulator system visual tasks are given and the effects of system parameters of these tasks are evaluated.

  17. United States orbital transfer vehicle programs

    Science.gov (United States)

    Gunn, Charles R.

    The United States will rely on five orbital transfer vehicles to carry spacecraft to higher energy orbits than achievable by the Space Shuttle or various Expendable Launch Vehicles (ELV). These vehicles are the Payload Assist Module-Delta (PAM-D), an upgraded version designated PAM-DII, the Inertial Upper Stage (IUS), the Transfer Orbit Stage (TOS), and the Orbital Maneuvering Vehicle (OMV). Development of these vehicles have evolved through contrasting cultures of government and commercial management. The spectrum of their capabilities range from providing spacecraft with only a preprogrammed perigee velocity additions to man-in-the-loop remote controlled spacecraft rendezvous, docking, retrieval and return to a space base; either the Shuttle or the Space Station Freedom. The PAM-D, PAM-DII, and IUS are now nearing maturity. Their characteristics, flight record, costs, and projected future uses are defined. The TOS and OMV are currently in development with first uses scheduled in 1992 and 1993, respectively. The TOS is being commercially developed while the OMV is government developed. The TOS and OMV capabilities, constraints, and costs are reviewed.

  18. Origin of the Spin-Orbit Interaction

    CERN Document Server

    Spavieri, Gianfranco

    2015-01-01

    We consider a semi-classical model to describe the origin of the spin-orbit interaction in a simple system such as the hydrogen atom. The interaction energy U is calculated in the rest-frame of the nucleus, around which an electron, having linear velocity v and magnetic dipole-moment mu, travels in a circular orbit. The interaction energy U is due to the coupling of the induced electric dipole p=(v/c)x mu with the electric field En of the nucleus. Assuming the radius of the electron's orbit remains constant during a spin-flip transition, our model predicts that the energy of the system changes by Delta_E = U/2, the factor 1/2 emerging naturally as a consequence of equilibrium and the change of the kinetic energy of the electron. The correct 1/2 factor for the spin-orbit coupling energy is thus derived without the need to invoke the well-known Thomas precession in the rest-frame of the electron.

  19. 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

  20. 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

  1. Role of Berry phase theory for describing orbital magnetism: From magnetic heterostructures to topological orbital ferromagnets

    Science.gov (United States)

    Hanke, J.-P.; Freimuth, F.; Nandy, A. K.; Zhang, H.; Blügel, S.; Mokrousov, Y.

    2016-09-01

    We address the importance of the modern theory of orbital magnetization for spintronics. Based on an all-electron first-principles approach, we demonstrate that the predictive power of the routinely employed "atom-centered" approximation is limited to materials like elemental bulk ferromagnets, while the application of the modern theory of orbital magnetization is crucial in chemically or structurally inhomogeneous systems such as magnetic thin films, and materials exhibiting nontrivial topology in reciprocal and real space, e.g., Chern insulators or noncollinear systems. We find that the modern theory is particularly crucial for describing magnetism in a class of materials that we suggest here—topological orbital ferromagnets.

  2. 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.

  3. Orbital Compartment Syndrome Leading to Visual Loss following Orbital Floor Reconstruction.

    Science.gov (United States)

    Susarla, Srinivas M; Nam, Arthur J; Dorafshar, Amir H

    2016-06-01

    Reconstruction of posttraumatic orbital defects carries the attendant risk of injury to the ocular adnexa, globe, and associated neurovascular structures. Blindness following repair of orbital fractures is an infrequent but well-documented phenomenon. Visual acuity loss can be related to direct intraoperative injury to the optic nerve, retinal arterial occlusion, or delayed presentation of acute optic nerve injury. In this report, we document a unique case of acute optic nerve infarction occurring 14 hours following orbital floor exploration and repair in a 56-year-old man.

  4. The Orbital Evolution of 2007 VA85, an Amor-type Asteroid on a Retrograde Orbit.

    Science.gov (United States)

    Kankiewicz, P.; Włodarczyk, I.

    2010-06-01

    Among the known population of asteroids on retrograde orbits (i > 90°) we found an object classified as an Amor-type asteroid. During the analysis of the first results of astrometry, we found some possible Earth-impact solutions for this asteroid. After taking into account the latest observations, we excluded any significant impact solution. However, this asteroid is the first known example of potentially hazardous object on a retrograde orbit. We also investigated the orbital evolution of 2007 VA85 (1 My in the past), obtaining possible scenarios of its dynamical origin.

  5. Computed tomography of the orbital tumors

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jai Korl; Lee, Hwang Bok; Kang, Eun Young; Seol, Hae Young; Suh, Won Hyuck [College of Medicine, Korea University, Seoul (Korea, Republic of); Ahn, Byeong Yeob [Han Mi Hospital, Seoul (Korea, Republic of)

    1987-04-15

    The development of computed tomography (CT) provided a noninvasive safe technique for imaging the orbit in any plane exquisitely demonstrating its normal anatomy as well as its pathologic process. The orbit is an ideal structure to be examined by CT because of large difference of absorption values between the intraorbital fat, muscle, optic nerve and vessels. In this study, the authors reviewed CT findings of 66 pathologically proven orbital tumors and tumorous conditions among the total of 98 cases who had taken orbital CT scan because if exophthalmos, ocular pain, diplopia and other ophthalmologic symptoms suggesting orbital masses during the period of 3 years. For the analysis of characteristic CT findings of the orbital lesions, all lesions are divided into 4 groups according to the site of origin, i.e., tumors arising in the eyeball (group 1); from intraconal space (group 2); from extraconal space (group 3); and from extraorbital regions (group 4). The results are as follows; 1.Extra tumor detection and localization was possible in 63 cases. Thus the detection rate was 95% with CT scan. 2.Among 36 males and 30 females, their age ranged from 10 months to 72 years. 3.Intraocular tumors (group 1) were 10 cases. Retinoblastoma occurred wholly in the young children under 5 years and combined with calcification in 57%. Choroidal melanoma occurred wholly in adults. 4.Intraconal tumors (group 2) were 9 cases. Vascular tumors (7 cases) were the most frequent and well enhancing mass. 5.The tumors arising in the extraconal region (group 3) were pseudotumor (12 cases), lymphoma (3 cases), dermoid cyst (4 cases), metastasis (2 cases), adenoid cystic carcinoma (1 case) and teratoma (1 case). A case of lymphoma demonstrating retrobulbar ill defined mass with scleral l thickening could not be differentiated from the pseudotumor which showing similar finding. 6.The lesions arising from extraorbital region (group 4) were PNS cancer (9 cases), mucocele (3 cases), lid cancer (4

  6. Periodic orbits around areostationary points in the Martian gravity field

    CERN Document Server

    Liu, Xiaodong; Ma, Xingrui

    2012-01-01

    This study investigates the problem of areostationary orbits around Mars in the three-dimensional space. Areostationary orbits are expected to be used to establish a future telecommunication network for the exploration of Mars. However, no artificial satellites have been placed in these orbits thus far. In this paper, the characteristics of the Martian gravity field are presented, and areostationary points and their linear stability are calculated. By taking linearized solutions in the planar case as the initial guesses and utilizing the Levenberg-Marquardt method, families of periodic orbits around areostationary points are shown to exist. Short-period orbits and long-period orbits are found around linearly stable areostationary points, and only short-period orbits are found around unstable areostationary points. Vertical periodic orbits around both linearly stable and unstable areostationary points are also examined. Satellites in these periodic orbits could depart from areostationary points by a few degree...

  7. The Apsidal Precession for Low Earth Sun Synchronized Orbits

    Directory of Open Access Journals (Sweden)

    Shkelzen Cakaj

    2015-09-01

    Full Text Available By nodal regression and apsidal precession, the Earth flattering at satellite low Earth orbits (LEO is manifested. Nodal regression refers to the shift of the orbit’s line of nodes over time as Earth revolves around the Sun. Nodal regression is orbit feature utilized for circular orbits to be Sun synchronized. A sun¬-synchronized orbit lies in a plane that maintains a fixed angle with respect to the Earth-Sun direction. In the low Earth Sun synchronized circular orbits are suited the satellites that accomplish their photo imagery missions. Nodal regression depends on orbital altitude and orbital inclination angle. For the respective orbital altitudes the inclination window for the Sun synchronization to be attained is determined. The apsidal precession represents major axis shift, respectively the argument of perigee deviation. The apsidal precession simulation, for inclination window of sun synchronized orbital altitudes, is provided through this paper.

  8. Surgical approach to the superior mid-orbit.

    Science.gov (United States)

    Krohn-Hansen, Dag; Nicolaissen, Bjørn; Meling, Torstein R; Haaskjold, Erling

    2013-09-01

    Access to the superior mid-orbit is required for procedures on the levator muscle in the correction of upper eyelid ptosis and in surgery aimed at local lesions in this region. The purpose with this human cadaver study was to clarify the anatomical substrate for a surgical approach to the levator muscle and the upper mid-orbit structures, in which the orbital septum and the retroseptal fat pad is not harmed during surgery. Macro-anatomical dissections and histological examinations were performed on five human orbits from three formalin embalmed cadaver heads. It was found that the orbital septum extends posteriorly from its junction with the levator aponeurosis. This posterior continuation of the orbital septum encloses the superior orbital fat pad and separates this from the anterior surface of the levator muscle. In between the orbital septum and the levator, there is a dissection space that provides a minimal invasive access corridor to the structures in the upper mid-orbit.

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

    Science.gov (United States)

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

    2017-08-16

    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. The International Space Station on-orbit tester

    Science.gov (United States)

    Pierotti, Elizabeth; Atodaria, Jitu

    2001-02-01

    The International Space Station (ISS) program has identified specific Orbital Replaceable Units (ORUs) as candidates for on-orbit intermediate level maintenance. Performing intermediate level maintenance on-orbit will allow sparing at the Shop Replaceable Unit (SRU) level rather than the ORU level. This will minimize cost and volume to transport replaceable units to and from orbit, minimize stowage on-orbit, and maximize on-orbit spare availability that will in turn minimize system downtime. To accomplish on-orbit intermediate level maintenance, additional requirements for fault isolation and confidence testing must be implemented. Test equipment used on-ground to perform fault isolation and acceptance testing is large and heavy. Consideration for weight and volume is an important factor for any test equipment that is to be transported, used and stowed on-orbit. This paper summarizes a phased approach to testing electronic hardware on-orbit with minimal additional weight and volume for the test equipment. .

  11. The EJSM Jupiter-Ganymede Orbiter

    Science.gov (United States)

    Blanc, M.; Lebreton, J.-P.; Stankov, A.; Greeley, R.; Pappalardo, R. T.; Fujimoto, M.

    2008-09-01

    The Europa-Jupiter System Mission (EJSM), currently subject of a joint study by NASA, ESA and JAXA, would combine a fleet of three satellites in order to investigate in depth many questions related to the Jupiter System. These investigations are essential for our understanding of the emergence and evolution of habitable worlds, not only within the Solar System, but also for extrasolar planet investigations. Scientific targets of EJSM focus on Europa and Ganymede as a key pair of Galilean satellites, to address the questions on their habitability, formation, and internal structure, as well as the coupling with the whole Jovian system: Jupiter's atmosphere and interior, magnetosphere and magnetodisk.. In combination with a Jupiter Europa Orbiter (JEO that would be provided by NASA) and a Jupiter Magnetospheric Orbiter (JMO that would be provided by JAXA), ESA is studying a Jupiter Ganymede Orbiter (JGO). The mission scenario includes a launch in 2020 with a transfer time to Jupiter of ~6 years. After the orbit insertion around Jupiter, a first phase (~2 years) will be devoted to Jupiter system and Callisto studies, with multiple flybys of Callisto planned at low altitude (~200 km), followed by a Ganymede orbit insertion and extensive study of Ganymede (~1 year). In depth comparative study of inner (Io and Europe) and outer (Ganymede and Callisto) satellites with combined payload of JEO and JGO will address the question of the geologic relative evolution of the satellites. On JGO, the transport phenomena in the magnetosphere of Jupiter will be studied in combination with JMO, and the Ganymede magnetosphere will be observed in situ. Jupiter atmosphere investigations on JGO will focus on coupling phenomena between troposphere, stratosphere and mesosphere, the stratospheric composition and the question of thermospheric heating.

  12. Orbital maneuvering vehicle: A new capability

    Science.gov (United States)

    Huber, William G.

    The Orbital Maneuvering Vehicle (OMV) is a reusable, remotely controlled, free-flying vehicle being developed by NASA to perform a wide range of on-orbit missions and services in support of orbiting spacecraft. The OMV is capable of satellite delivery, retrieval, reboost, controlled deorbit, viewing, and subsatellite support missions. It is an important extension to the Space Transportation System and a key element of the Space Station operational scenario. The OMV can operate from the Shuttle, the Space Station, or can be space based. The OMV, being 15 ft in diameter and approximately 4 1/2 thick, mounts directly into the Shuttle payload bay. The vehicle design is highly modular, consisting of a Short Range Vehicle containing both hydrazine and cold gas RCS systems and all the avionics systems for electrical power, communications, data management, guidance, navigation, and 6-degree of freedom control. This vehicle weighs approximately 6,500 lb and can accomplish a high percentage of the project missions. For high delta-velocity missions, a bipropellant Propulsion Module (approximately 11,000lb) is added, giving a total weight of 17,500 lb. This module can be exchanged on orbit to effect bipropellant refueling. All the RCS and avionics modules are replaceable on orbit for maintenance. The OMV development program was initiated in 1986 with the selection of TRW as the prime contractor. The first flight is projected for 1991. An early planned use of OMV is to reboost the Hubble Space Telescope when required because of atmospheric drag. This paper contains details of the program status, vehicle description, and mission capabilities. The purpose of the paper is to acquaint the international space community with OMV capabilities and to stimulate the identification of new and unique mission applications.

  13. 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.

  14. Evaluation of CHAMP Satellite Orbit with SLR Measurements

    Institute of Scientific and Technical Information of China (English)

    QIN Xianping; YANG Yuanxi

    2005-01-01

    The technique of Evaluating CHAMP satellite orbit with SLR measurements is presented. As an independent evaluation of the orbit solution, SLR data observed from January 1 to 16, 2002 are processed to compute the residuals after fixing the GFZ's post science orbits solutions. The SLR residuals are computed as the differences of the SLR measurements minus the corresponding distances between the SLR station and the GPS-derived orbit positions. On the basis of the SLR residuals analysis, it is found that the accuracy of GFZ's post science orbits is better than 10 em and that there is no systematic error in GFZ's post science orbits.

  15. Computer Aided Ballistic Orbit Classification Around Small Bodies

    Science.gov (United States)

    Villac, Benjamin F.; Anderson, Rodney L.; Pini, Alex J.

    2016-09-01

    Orbital dynamics around small bodies are as varied as the shapes and dynamical states of these bodies. While various classes of orbits have been analyzed in detail, the global overview of relevant ballistic orbits at particular bodies is not easily computed or organized. Yet, correctly categorizing these orbits will ease their future use in the overall trajectory design process. This paper overviews methods that have been used to organize orbits, focusing on periodic orbits in particular, and introduces new methods based on clustering approaches.

  16. A new method for orbit determination: Unit vector method

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, a method of orbit determination is presented according to the principle of unit vector method (UVM). The model and arithmetic are improved and it not only suits initial orbit determination with short arc data, it also suits orbit improvement with data longer. It is also suitable for orbit of any eccentricity and any inclination. It omits most partial derivatives of all the elements which must be calculated in classical differential orbit improvement (DOI), so, it is more efficient than DOI, and the accuracy of orbit determination and convergence of algorithm are also improved appreciably.

  17. NUMERICAL INTEGRATION OF A SATELLITE ORBIT WITH KS TRANSFORMATION

    OpenAIRE

    Piñeros, Jhonathan Murcia; Koffi, Maxime; Kuga, Helio Koiti

    2017-01-01

    A satellite orbit is mainly influenced by central body gravitational forces. For a satellite in LEO (Low Earth Orbit), MEO (Medium Earth Orbit) or GEO (Geosynchronous Earth Orbit) the Earth´s gravity distribution and other perturbations determine the position and velocity changes in function of time. If the motion is around a spherical body with homogenous mass distribution and without perturbative forces, the orbit must be cyclic like the Two Body Problem (TBP) or Keplerian Orbit. Different ...

  18. 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

  19. Benefits of a Geosynchronous Orbit (GEO) Observation Point for Orbit Determination

    Science.gov (United States)

    Byrne, R.; Griesmeyer, M.; Schmidt, R.; Shaddix, J.; Bodette, D.

    2011-09-01

    Determining orbits of unknown objects is a fundamental space situational awareness activity. The U.S. Space Surveillance Network (SSN) currently relies on ground-based radars, optical telescopes, and the Space Based Space Surveillance (SBSS) System. The SBSS system overcomes many of the pitfalls of optical ground-based systems like limited observation times (e.g. weather and time of day) and measurement uncertainty from atmospheric effects. However, the SBSS satellite is in a low earth orbit (630 km, sun synchronous), and must look “up” for GEO objects. This paper analyzes the potential benefits of a GEO observation point for performing metric observations that are combined with ground-based data. Several different scenarios are considered to quantify the reduction in orbit uncertainty from these types of observations. All results are derived using an Extended Kalman filter (EKF) to process the observations. Orbital uncertainties are expressed in terms of the error covariance.

  20. The Mars Reconnaissance Orbiter Mission: From Launch to the Primary Science Orbit

    Science.gov (United States)

    Johnston, Martin D.; Graf, James E.; Zurek, Richard W.; Eisen, Howard J.; Jai, Benhan; Erickson, James K.

    2007-01-01

    The Mars Reconnaissance Orbiter (MRO) was launched from Cape Canaveral Air Force Station, Florida, USA, aboard an Atlas V-401 launch vehicle on August 12, 2005. The MRO spacecraft carries a very sophisticated scientific payload. Its primary science mission is to to provide global, regional survey, and targeted observations from a low altitude orbit for one Martian year (687 Earth days). After a seven month interplanetary transit, the spacecraft fired its six main engines and established a highly elliptical capture orbit at Mars. During the post-MOI early check-out period, four instruments acquired engineering-quality data. This was followed by five months of aerobraking operations. After aerobraking was terminated, a series of propulsive maneuvers were used to establish the desired low altitude science orbit. As the spacecraft is readied for its primary science mission, spacecraft and instrument checkout and deployment activities have continued.

  1. Orbital physics in the perovskite Ti oxides

    Energy Technology Data Exchange (ETDEWEB)

    Mochizuki, Masahito [Department of Physics, University of Tokyo, Hongo, Tokyo 113-0033 (Japan); Imada, Masatoshi [Institute for Solid State Physics, University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)

    2004-11-01

    Titanate compounds have been recognized as key materials for understanding the coupling of magnetism and orbitals in strongly correlated electron systems. In the perovskite Ti oxide RTiO{sub 3} (where R represents the trivalent rare-earth ions), which is a typical Mott-Hubbard insulator, the Ti t{sub 2g} orbitals and spins in the 3d{sup 1} state couple each other through the strong electron correlations, resulting in a rich variety of orbital-spin phases. One way of controlling the coupling is to change the tiltings of the TiO{sub 6} octahedra (namely the GdFeO{sub 3}-type distortion) by varying the R ions, through which the relative ratio of the electron bandwidth to the Coulomb interaction is controlled. With this control, these Mott insulators exhibit an antiferromagnetic-to-ferromagnetic (AFM-FM) phase transition, which has turned out to be a consequence of rich orbital physics in these materials. The origin and nature of orbital-spin structures of these Mott insulators have been intensively studied both experimentally and theoretically. When the Mott insulators are doped with carriers, the titanates show touchstone properties of the filling controlled Mott transition. In this paper, we first review the state of the art on the studies for understanding physics contained in the properties of the perovskite titanates. On the properties of the insulators, we focus on the following three topics: (1) the origin and nature of the ferromagnetism as well as the orbital ordering in the compounds with relatively small R ions such as GdTiO{sub 3} and YTiO{sub 3} (2) the origin of the G-type antiferromagnetism and the orbital state in LaTiO{sub 3} and (3) the orbital-spin structures in other AFM(G) compounds with relatively large R ions (R = Ce, Pr, Nd and Sm). On the basis of these discussions, we discuss the whole phase diagram together with mechanisms of the magnetic phase transition. On the basis of the microscopic understanding of the orbital-spin states, we show that

  2. Orbiter-to-orbiter tomography: a potential approach for small planetary objects

    CERN Document Server

    Pursiainen, Sampsa

    2016-01-01

    The goal of this paper is to advance mathematical and computational methodology for orbiter-to-orbiter radio tomography of small planetary objects. In this study, an advanced full waveform forward model is coupled with a total variation based inversion technique. We use a satellite formation model in which a single unit receives a signal that is transmitted by one or more transponder satellites. Numerical results for a 2D domain are presented.

  3. Orbital change following Le Fort III advancement in syndromic craniosynostosis: quantitative evaluation of orbital volume, infra-orbital rim and globe position.

    Science.gov (United States)

    Nout, Erik; van Bezooijen, Jine S; Koudstaal, Maarten J; Veenland, Jifke F; Hop, Wim C J; Wolvius, Eppo B; van der Wal, Karel G H

    2012-04-01

    Patients with syndromic craniosynostosis suffering from shallow orbits due to midface hypoplasia can be treated with a Le Fort III advancement osteotomy. This study evaluates the influence of Le Fort III advancement on orbital volume, position of the infra-orbital rim and globe. In pre- and post-operative CT-scans of 18 syndromic craniosynostosis patients, segmentation of the left and right orbit was performed and the infra-orbital rim and globe were marked. By superimposing the pre- and post-operative scans and by creating a reference coordinate system, movements of the infra-orbital rim and globe were assessed. Orbital volume increased significantly, by 27.2% for the left and 28.4% for the right orbit. Significant anterior movements of the left infra-orbital rim of 12.0mm (SD 4.2) and right infra-orbital rim of 12.8mm (SD 4.9) were demonstrated. Significant medial movements of 1.7mm (SD 2.2) of the left globe and 1.5mm (SD 1.9) of the right globe were demonstrated. There was a significant correlation between anterior infra-orbital rim movement and the increase in orbital volume. Significant orbital volume increase has been demonstrated following Le Fort III advancement. The position of the infra-orbital rim was moved forward significantly, whereas the globe position remained relatively unaffected. Copyright © 2011 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  4. Correlation between the 2-Dimensional Extent of Orbital Defects and the 3-Dimensional Volume of Herniated Orbital Content in Patients with Isolated Orbital Wall Fractures

    Science.gov (United States)

    Cha, Jong Hyun; Moon, Myeong Ho; Lee, Yong Hae; Koh, In Chang; Kim, Kyu Nam; Kim, Chang Gyun

    2017-01-01

    Background The purpose of this study was to assess the correlation between the 2-dimensional (2D) extent of orbital defects and the 3-dimensional (3D) volume of herniated orbital content in patients with an orbital wall fracture. Methods This retrospective study was based on the medical records and radiologic data of 60 patients from January 2014 to June 2016 for a unilateral isolated orbital wall fracture. They were classified into 2 groups depending on whether the fracture involved the inferior wall (group I, n=30) or the medial wall (group M, n=30). The 2D area of the orbital defect was calculated using the conventional formula. The 2D extent of the orbital defect and the 3D volume of herniated orbital content were measured with 3D image processing software. Statistical analysis was performed to evaluate the correlations between the 2D and 3D parameters. Results Varying degrees of positive correlation were found between the 2D extent of the orbital defects and the 3D herniated orbital volume in both groups (Pearson correlation coefficient, 0.568−0.788; R2=32.2%−62.1%). Conclusions Both the calculated and measured 2D extent of the orbital defects showed a positive correlation with the 3D herniated orbital volume in orbital wall fractures. However, a relatively large volume of herniation (>0.9 cm3) occurred not infrequently despite the presence of a small orbital defect (<1.9 cm2). Therefore, estimating the 3D volume of the herniated content in addition to the 2D orbital defect would be helpful for determining whether surgery is indicated and ensuring adequate surgical outcomes. PMID:28194344

  5. The Dynamics of Orbit-Clearing for Planets on Eccentric Orbits

    Science.gov (United States)

    Hastings, Danielle; Margot, Jean-Luc

    2016-10-01

    The third requirement in the 2006 International Astronomical Union (IAU) definition of a planet is that the object has cleared the neighborhood around its orbit. Margot (2015) proposed a metric that quantitatively determines if an object has enough mass to clear an orbital zone of a specific extent within a defined time interval. In this metric, the size of the zone to be cleared is given by CRH, where C is a constant and RH is the Hill Radius. Margot (2015) adopts C=2*31/2 to describe the minimum extent of orbital clearing on the basis of the planet's feeding zone. However, this value of C may only apply for eccentricities up to about 0.3 (Quillen & Faber 2006). Here, we explore the timescales and boundaries of orbital clearing for planets over a range of orbital eccentricities and planet-star mass ratios using the MERCURY integration package (Chambers 1999). The basic setup for the integrations includes a single planet orbiting a star and a uniform distribution of massless particles extending beyond CRH. The system is integrated for at least 106 revolutions and the massless particles are tracked in order to quantify the timescale and extent of the clearing.

  6. Interacting Binaries with Eccentric Orbits. III. Orbital Evolution due to Direct Impact and Self-Accretion

    CERN Document Server

    Sepinsky, J F; Kalogera, V; Rasio, F A

    2010-01-01

    The rapid circularization and synchronization of the stellar components in an eccentric binary system at the onset of mass transfer is a fundamental assumption common to all binary stellar evolution and population synthesis codes, even though the validity of this assumption is questionable both theoretically and observationally. Here we calculate the evolution of the orbital elements of an eccentric binary through the direct three-body integration of a massive particle ejected through the inner Lagrangian point of the donor star at periastron. The trajectory of this particle leads to three possible outcomes: direct accretion onto the companion star within a single orbit, self-accretion back onto the donor star within a single orbit, or a quasi-periodic orbit around the companion star, possibly leading to the formation of a disk. We calculate the secular evolution of the binary orbit in the first two cases and conclude that direct impact accretion can increase as well as decrease the orbital semi-major axis an...

  7. Beagle 2 and NASA's Mars 2003 Orbiter: A Unique Exobiology Opportunity with an Orbiter

    Science.gov (United States)

    Gibson, Everett K., Jr.; Pillinger, Colin T.; Thatcher, John; Westall, Frances

    2000-01-01

    With the exploration strategy for Mars undergoing reexamination, the opportunity exists for the incorporation of the 60 kg Beagle 2 lander, developed in the United Kingdom for inclusion on ESA's 2003 Mars Express mission, with NASA's Mars 2003 orbiter derived from the Mars Global Orbiter. The combination of Beagle 2 with a Mars orbiter would result in a unique mission which could obtain information on Mars' life, climate and resources both from orbit as well as on the surface of the planet. Beagle 2 has been developed in the LJK for ESA as a low-cost opportunity to study the exobiology of Mars and the spacecraft is in its final stages of manufacture. Only limited modifications to the Beagle 2 package would be required for inclusion on NASA's Mars 2003 orbiter. With the ESA Mars Express mission launch in 2003 and a potential NASA Mars orbiter in 2003, both Beagle 2 landers on Mars would offer a low-cost, decreased risk and increased science return opportunity for the exploration of Mars at two distinct geologically interesting sites.

  8. Deep Orbital Dermoid Cyst Bulging into the Superior Orbital Fissure: Clinical Presentation and Management

    Science.gov (United States)

    Kumar, Ravinder; Vyas, Kapil; Jaiswal, Gagan; Bhargava, Abhishek; Kundu, Jyoti

    2017-01-01

    Purpose: To present a case of deep orbital dermoid cyst with emphasis on clinical presentation, imaging spectrum, differential diagnosis and management. Case Report: A 28-year-old female was referred to our hospital with chief complaint of drooping of right eyelid and progressive headache. Ocular motility, visual acuity and fundus examination were normal. computed tomography (CT) and magnetic resonance imaging (MRI) revealed a well-defined, intraosseous deep orbital dermoid cyst (5.9 mm × 12.5 mm) located near the apex of right orbit, extending from greater wing of sphenoid into the superior orbital fissure. Due to occulomotor nerve (superior and inferior divisions) compression which passes through the superior orbital fissure, ipsilateral headache and ptosis occurred. Complete surgical excision of cyst was performed using noninvasive extracranial lateral orbitotomy approach. After removal of the cyst, curette and cutting drill were used to thoroughly remove any residual cystic content. Histopathological analysis confirmed the diagnosis. The healing was uneventful postoperatively. Conclusion: CT and MRI are easy, reliable, safe and effective imaging methods for establishing the diagnosis of orbital dermoid cyst. Size, location and manifestations are the most important determinants of the disease management. Complete surgical excision without rupture of the cyst is the treatment of choice. PMID:28299014

  9. Dynamical modeling and lifetime analysis of geostationary transfer orbits

    Science.gov (United States)

    Wang, Yue; Gurfil, Pini

    2016-11-01

    The dynamics and lifetime reduction of geostationary transfer orbits (GTOs) are of great importance to space debris mitigation. The orbital dynamics, subjected to a complex interplay of multiple perturbations, are complicated and sensitive to the initial conditions and model parameters. In this paper, a simple but effective non-singular orbital dynamics model in terms of Milankovitch elements is derived. The orbital dynamics, which include the Earth oblateness, luni-solar perturbations, and atmospheric drag, are averaged over the orbital motion of the GTO object, or, as needed, also over the orbital motions of the Moon and Sun, to eliminate the short-period terms. After the averaging process, the effect of the atmospheric drag assumes a simple analytical form. The averaged orbital model is verified through a numerical simulation compared with commercial orbit propagators. GTO lifetime reduction by using the luni-solar perturbations is studied. It is shown that the long-period luni-solar perturbation is induced by the precession of the GTO orbital plane and apsidal line, whereas the short-period perturbation is induced by the periodic luni-solar orbital motions. The long- and short-period perturbations are isolated and studied separately, and their global distribution with respect to the orbital geometry is given. The desired initial orbital geometry with a short orbital lifetime is found and verified by a numerical simulation.

  10. 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

  11. 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....

  12. LiAISON: Linked, Autonomous Interplanetary Satellite Orbit Navigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new navigation technique known as LiAISON (Linked Autonomous Interplanetary Satellite Orbit Navigation) may be used to propel the benefits of GPS to new orbits,...

  13. Lunar Orbit Stability for Small Satellite Mission Design

    Science.gov (United States)

    Dono, Andres

    2015-01-01

    The irregular nature of the lunar gravity field will severely affect the orbit lifetime and behavior of future lunar small satellite missions. These spacecraft need stable orbits that do not require large deltaV budgets for station-keeping maneuvers. The initial classical elements of any lunar orbit are critical to address its stability and to comply with mission requirements. This publication identifies stable regions according to different initial conditions at the time of lunar orbit insertion (LOI). High fidelity numerical simulations with two different gravity models were performed. We focus in low altitude orbits where the dominant force in orbit propagation is the existence of unevenly distributed lunar mass concentrations. These orbits follow a periodic oscillation in some of the classical elements that is particularly useful for mission design. A set of orbital maintenance strategies for various mission concepts is presented.

  14. 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...

  15. 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.

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

    NARCIS (Netherlands)

    Geven, Mike A.; Varjas, Viktor; Kamer, Lukas; Wang, Xinjiang; Peng, Jiang; Eglin, David; 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 supp

  17. Orbit design for the Laser Interferometer Space Antenna (LISA)

    Institute of Scientific and Technical Information of China (English)

    Gerhard; HEINZEL; Albrecht; RDIGER

    2010-01-01

    The Laser Interferometer Space Antenna (LISA) is a joint ESA-NASA mission for detecting low-frequency gravitational waves in the frequency range from 0.1 mHz to 1 Hz, by using accurate laser interferometry between three spacecrafts, which will be launched around 2018 and one year later reach their operational orbits around the Sun. In order to operate successfully, it is crucial for the constellation of the three spacecrafts to have extremely high stability. Based on the study of operational orbits for a 2015 launch, we design the operational orbits of beginning epoch on 2019-03-01, and introduce the method of orbit design and optimization. We design the orbits of the transfer from Earth to the operational orbits, including launch phase and separation phase; furthermore, the relationship between energy requirement and flight time of these two orbit phases is investigated. Finally, an example of the whole orbit design is presented.

  18. 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.

  19. [Comprehensive ultrasound diagnosis of orbital tumors and preudotumors].

    Science.gov (United States)

    Aznabaev, M T; Gabdrakhmanova, A F; Gaĭsina, G F

    2006-01-01

    A comprehensive ultrasound examination was made in 37 patients with orbital tumors and pseudotumors. The basic differential diagnostic sonographic and Doppler signs were defined in capillary hemangioma, vasculitis at the stage of infiltration and malignancies of the orbit.

  20. Primary extraosseous Ewing sarcoma of the orbit.

    Science.gov (United States)

    Alio, Jorge L; Sales-Sanz, Marco; Vaz, Maria A; Barrancos, Constanza; Reguero, Maria E; Diamantopoulus, Jorge; Poveda, Pedro

    2013-01-01

    A 40-year-old man presented with painless, progressive vision loss and mild proptosis of the OD. CT revealed a right intraconal mass with slight penetration of the optic canal not contiguous with any bony structure. Incisional biopsy through a transfrontal orbitotomy revealed a diffuse growth of homogeneous, small, round cells. Immunohistochemical stains were positive for vimentin and MIC2 (CD99), and the translocation at EWS gene (22q12) was detected. Metastatic workup and a full-body bone scan were negative, confirming primary orbital extraosseous Ewing sarcoma. The patient received neoadjuvant chemotherapy and an orbital exenteration with preservation of eyelids and conjunctiva. He also received adjuvant chemotherapy and local radiotherapy, and he has remained disease-free for almost 3 years.

  1. Ophthalmic plastic and orbital surgery in Taiwan.

    Science.gov (United States)

    Hsu, Chi-Hsin; Lin, I-Chan; Shen, Yun-Dun; Hsu, Wen-Ming

    2014-06-01

    We describe in this paper the current status of ophthalmic plastic and orbital surgery in Taiwan. Data were collected from the Bureau of National Health Insurance of Taiwan, the Bulletin of the Taiwan Ophthalmic Plastic and Reconstructive Society, and the Statistics Yearbook of Practicing Physicians and Health Care Organizations in Taiwan by the Taiwan Medical Association. We ascertained that 94 ophthalmologists were oculoplastic surgeons and accounted for 5.8% of 1621 ophthalmologists in Taiwan. They had their fellowship training abroad (most ophthalmologists trained in the United States of America) or in Taiwan. All ophthalmologists were well trained and capable of performing major oculoplastic surgeries. The payment rates by our National Health Insurance for oculoplastic and orbital surgeries are relatively low, compared to Medicare payments in the United States. Ophthalmologists should promote the concept that oculoplastic surgeons specialize in periorbital plastic and aesthetic surgeries. However, general ophthalmologists should receive more educational courses on oculoplastic and cosmetic surgery.

  2. Orbital magnetization in dilute ferromagnetic semiconductors

    Science.gov (United States)

    Śliwa, Cezary; Dietl, Tomasz

    2014-07-01

    The relationship between the modern and classical Landau's approach to carrier orbital magnetization is studied theoretically within the envelope function approximation, taking ferromagnetic (Ga,Mn)As as an example. It is shown that while the evaluation of hole magnetization within the modern theory does not require information on the band structure in a magnetic field, the number of basis wave functions must be much larger than in the Landau approach to achieve the same quantitative accuracy. A numerically efficient method is proposed, which takes advantages of these two theoretical schemes. The computed magnitude of orbital magnetization is in accord with experimental values obtained by x-ray magnetic circular dichroism in (III,Mn)V compounds. The direct effect of the magnetic field on the hole spectrum is studied too, and employed to interpret a dependence of the Coulomb blockade maxima on the magnetic field in a single electron transistor with a (Ga,Mn)As gate.

  3. 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.

  4. 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...

  5. In-orbit performance of BSE transponders

    Science.gov (United States)

    Fukuchi, H.; Yamamoto, M.; Yazawa, N.; Morishita, Y.

    The Japanese Medium Scale Broadcasting Satellite for Experimental Purposes (BSE) was successfully positioned in a geostationary orbit on April 26, 1978. Various kinds of transmission characteristics were periodically measured every half year including frequency characteristics, and input-output characteristics of each electronics unit which made up a high power, 100 W, transponder. No remarkable degradation of their characteristics was observed for about two years, and the characteristics of the in-orbit satellite transponders almost coincided with the designed values or the values measured prior to the launching. FM television signal (FM-TV) transmission characteristics were also measured periodically. From these measurements it was found that the qualities of the television picture and sound were not reduced to any extent by the high power transponders.

  6. 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.

  7. Sclerosing lesions of the orbit: A review

    Directory of Open Access Journals (Sweden)

    Gautam Lokdarshi

    2015-01-01

    Full Text Available Orbital sclerosing inflammation is a distinct group of pathologies characterized by indolent growth with minimal or no signs of inflammation. However, contrary to earlier classifications, it should not be considered a chronic stage of acute inflammation. Although rare, orbital IgG4-related disease has been associated with systemic sclerosing pseudotumor-like lesions. Possible mechanisms include autoimmune and IgG4 related defective clonal proliferation. Currently, there is no specific treatment protocol for IgG4-related disease although the response to low dose steroid provides a good response as compared to non-IgG4 sclerosing pseudotumor. Specific sclerosing inflammations (e.g. Wegener's disease, sarcoidosis, Sjogren's syndrome and neoplasms (lymphoma, metastatic breast carcinoma should be ruled out before considering idiopathic sclerosing inflammation as a diagnosis.

  8. 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 method...... seventies Jorgen W. Lund pointed out in lecture notes that the dynamic damping coe±cients of the bearing could be used to ¯nd the shaft orbit for dynamically loaded bearings. For simplicity the "Short-Width-Journal-Bearing Theory" is used as a basis for ¯nding the damping coe±cients in this work...

  9. Long-Term Stability of Horseshoe Orbits

    CERN Document Server

    Ćuk, Matija; Holman, Matthew J

    2012-01-01

    Unlike Trojans, horseshoe coorbitals are not generally considered to be long-term stable (Dermott and Murray, 1981; Murray and Dermott, 1999). As the lifetime of Earth's and Venus's horseshoe coorbitals is expected to be about a Gyr, we investigated the possible contribution of late-escaping inner planet coorbitals to the lunar Late Heavy Bombardment. Contrary to analytical estimates, we do not find many horseshoe objects escaping after first 100 Myr. In order to understand this behaviour, we ran a second set of simulations featuring idealized planets on circular orbits with a range of masses. We find that horseshoe coorbitals are generally long lived (and potentially stable) for systems with primary-to-secondary mass ratios larger than about 1200. This is consistent with results of Laughlin and Chambers (2002) for equal-mass pairs or coorbital planets and the instability of Jupiter's horseshoe companions (Stacey and Connors, 2008). Horseshoe orbits at smaller mass ratios are unstable because they must approa...

  10. Respiratory epithelial cysts of the orbit.

    Science.gov (United States)

    Goh, Rachel L Z; Hardy, Thomas G; Williams, Richard A; McNab, Alan A

    2016-10-01

    To describe post-traumatic and congenital respiratory epithelial cysts in the orbit, which are rare lesions with only 5 and 13 published cases, respectively. We reviewed all cases of respiratory epithelial cysts diagnosed at three institutions (two tertiary referral hospitals, one private clinic) between 1995 and 2015. We describe 10 cases of post-traumatic respiratory epithelial cyst (age range 23 - 82), presenting a mean of 17.4 years after their original trauma; and 3 congenital cases (age range 17-34). All but one case underwent surgical excision of the cyst and its lining, along with any surgical implant within the cyst. Two were recurrent after incomplete excision. Three presented with acute infection within the cyst. Respiratory epithelial orbital cysts are probably commoner than the paucity of published reports would suggest. Post-traumatic cysts often present many years after trauma, and may become secondarily infected. Complete surgical removal is recommended to prevent future recurrence.

  11. Sclerosing Lesions of the Orbit: A Review.

    Science.gov (United States)

    Lokdarshi, Gautam; Pushker, Neelam; Bajaj, Mandeep S

    2015-01-01

    Orbital sclerosing inflammation is a distinct group of pathologies characterized by indolent growth with minimal or no signs of inflammation. However, contrary to earlier classifications, it should not be considered a chronic stage of acute inflammation. Although rare, orbital IgG4-related disease has been associated with systemic sclerosing pseudotumor-like lesions. Possible mechanisms include autoimmune and IgG4 related defective clonal proliferation. Currently, there is no specific treatment protocol for IgG4-related disease although the response to low dose steroid provides a good response as compared to non-IgG4 sclerosing pseudotumor. Specific sclerosing inflammations (e.g. Wegener's disease, sarcoidosis, Sjogren's syndrome) and neoplasms (lymphoma, metastatic breast carcinoma) should be ruled out before considering idiopathic sclerosing inflammation as a diagnosis.

  12. Ectopic orbital meningioma: Fact or fiction?

    Science.gov (United States)

    Tan, Lee Teak; Stewart, Christopher M; Sheerin, Fintan; MacDonald, Brendan; Silva, Priy; Norris, Jonathan H

    2017-06-01

    Primary intraorbital ectopic meningiomas are rare and their existence remains controversial. We present a 30-year-old female with painless, non-axial proptosis and a palpable superomedial mass. The MRI demonstrated that the mass had no optic nerve sheath or sphenoid wing involvement and was initially reported to have no intracranial extension. The patient was initially thought to have an ectopic orbital meningioma. Subsequent multidisciplinary team (MDT) consultation and further specialist review of the MRI revealed a subtle dural tail connecting to an enhancing mass in the olfactory groove. Biopsy revealed a WHO Grade 1 transitional meningioma with an infiltrative pattern. We argue that some previously reported cases of ectopic meningioma may lack the requisite imaging to discover the primary disease. Our report highlights the importance of MRI in this group of patients and the role of a skull-base MDT with specialist neuroradiology input to determine the true origin and extent of these extradural orbital meningiomas.

  13. Software for Hydrogenic Atoms and Orbitals Visualization

    Directory of Open Access Journals (Sweden)

    Kowit KITTIWUTTHISAKDI

    2005-06-01

    Full Text Available A program was developed in java for hydrogenic atoms and orbitals visualization. The first 18 atoms in the periodic table were approximated with a hydrogenic wave-function. This simple hydrogenic wave-function allowed quick calculation for real-time interactive visualization. Electron cloud based models were employed and displayed by a ray-tracing technique. One or more orbitals that defined an atom could be selected and displayed. A user could zoom in, zoom out, and rotate the displayed cloud in real time. The approximation method for probability integrals was summation. The intensity of color at each point on the screen directly related to the integrated probability in finding the electron across the viewer%s eye path.

  14. Flight telerobotic servicer control from the Orbiter

    Science.gov (United States)

    Ward, Texas M.; Harlan, Don L.

    1989-01-01

    The research and work conducted on the development of a testbed for a display and control panel for the Flight Telerobotic Servicer (FTS) are presented. Research was conducted on both software and hardware needed to control the FTS. A breadboard was constructed and placed into a mockup of the aft station of the Orbiter spacecraft. This breadboard concept was then evaluated using a computer graphics representation of the Tinman FTS. Extensive research was conducted on the software requirements and implementation. The hardware selected for the breadboard was 'flight like' and in some cases fit and function evaluated. The breadboard team studied some of the concepts without pursuing in depth their impact on the Orbiter or other missions. Assumptions are made concerning payload integration.

  15. Orbital Solution & Fundamental Parameters of sigma Scorpii

    CERN Document Server

    North, J R; Tuthill, P G; Tango, W J; Robertson, J G

    2007-01-01

    The first orbital solution for the spectroscopic pair in the multiple star system sigma Scorpii, determined from measurements with the Sydney University Stellar Interferometer (SUSI), is presented. The primary component is of beta Cephei variable type and has been one of the most intensively studied examples of its class. The orbital solution, when combined with radial velocity results found in the literature, yields a distance of 174(+23,-18) pc, which is consistent with, but more accurate than the Hipparcos value. For the primary component we determine 18.4+/-5.4 M_sun, -4.12+/-0.34 mag and 12.7+/-1.8 R_sun for the mass, absolute visual magnitude and radius respectively. A B1 dwarf spectral type and luminosity class for the secondary is proposed from the mass determination of 11.9+/-3.1 M_sun and the estimated system age of 10 Myr.

  16. Modeling the climatic response to orbital variations.

    Science.gov (United States)

    Imbrie, J; Imbrie, J Z

    1980-02-29

    According to the astronomical theory of climate, variations in the earth's orbit are the fundamental cause of the succession of Pleistocene ice ages. This article summarizes how the theory has evolved since the pioneer studies of James Croll and Milutin Milankovitch, reviews recent evidence that supports the theory, and argues that a major opportunity is at hand to investigate the physical mechanisms by which the climate system responds to orbital forcing. After a survey of the kinds of models that have been applied to this problem, a strategy is suggested for building simple, physically motivated models, and a time-dependent model is developed that simulates the history of planetary glaciation for the past 500,000 years. Ignoring anthropogenic and other possible sources of variation acting at frequencies higher than one cycle per 19,000 years, this model predicts that the long-term cooling trend which began some 6000 years ago will continue for the next 23,000 years.

  17. Mesoscopic rings with spin-orbit interactions

    Energy Technology Data Exchange (ETDEWEB)

    Berche, Bertrand; Chatelain, Christophe; Medina, Ernesto, E-mail: berche@lpm.u-nancy.f [Statistical Physics Group, Institut Jean Lamour, UMR CNRS No 7198, Universite Henri Poincare, Nancy 1, B.P. 70239, F-54506 Vandoeuvre les Nancy (France)

    2010-09-15

    A didactic description of charge and spin equilibrium currents on mesoscopic rings in the presence of spin-orbit interaction is presented. Emphasis is made on the non-trivial construction of the correct Hamiltonian in polar coordinates, the calculation of eigenvalues and eigenfunctions and the symmetries of the ground-state properties. Spin currents are derived following an intuitive definition, and then a more thorough derivation is built upon the canonical Lagrangian formulation that emphasizes the SU(2) gauge structure of the transport problem of spin-1/2 fermions in spin-orbit active media. The quantization conditions that follow from the constraint of single-valued Pauli spinors are also discussed. The targeted students are those of a graduate condensed matter physics course.

  18. Orbit design for a space ambulance vehicle

    Science.gov (United States)

    Nelson, Walter C.

    A number of rendezvous maneuvers between space stations in geocentric orbits at altitudes ranging between 200 km and geosynchronous altitude are examined. Minimum time to complete rendezvous is studied for purposes of expediting crew patient transfer to an orbiting medical base station (MBS) for the stabilization of trauma and definitive care. The vehicle to be used for the crew patient transfer to the MBS is the space ambulance vehicle (SAV). The SAV is assumed to use two velocity impulses to complete rendezvous maneuvers between an SS and the MBS: an accelerating impulse when departing the SS and a second decelerating impulse prior to docking with the MBS. Recommendations are made concerning the planning of space operations which will reduce both time and propulsive energy for rendezvous maneuvers. It is suggested that throttleable engines be used when transferring a crew patient whose trauma could be exacerbated by excessive acceleration of the carrier vehicle.

  19. Fermionic orbital optimisation in tensor network states

    CERN Document Server

    Krumnow, C; Eisert, J

    2015-01-01

    Tensor network states and specifically matrix-product states have proven to be a powerful tool for simulating ground states of strongly correlated spin models. Recently, they have also been applied to interacting fermionic problems, specifically in the context of quantum chemistry. A new freedom arising in such non-local fermionic systems is the choice of orbitals, it being far from clear what choice of fermionic orbitals to make. In this work, we propose a way to overcome this challenge. We suggest a method intertwining the optimisation over matrix product states with suitable fermionic Gaussian mode transformations, hence bringing the advantages of both approaches together. The described algorithm generalises basis changes in the spirit of the Hartree-Fock methods to matrix-product states, and provides a black box tool for basis optimisations in tensor network methods.

  20. Orbital entanglement in bond-formation processes

    CERN Document Server

    Boguslawski, Katharina; Barcza, Gergely; Legeza, Ors; Reiher, Markus

    2013-01-01

    The accurate calculation of the (differential) correlation energy is central to the quantum chemical description of bond-formation and bond-dissociation processes. In order to estimate the quality of single- and multi-reference approaches for this purpose, various diagnostic tools have been developed. In this work, we elaborate on our previous observation [J. Phys. Chem. Lett. 3, 3129 (2012)] that one- and two-orbital-based entanglement measures provide quantitative means for the assessment and classification of electron correlation effects among molecular orbitals. The dissociation behavior of some prototypical diatomic molecules features all types of correlation effects relevant for chemical bonding. We demonstrate that our entanglement analysis is convenient to dissect these electron correlation effects and to provide a conceptual understanding of bond-forming and bond-breaking processes from the point of view of quantum information theory.