Science.gov

Sample records for circular nonbridging external

  1. Analytical study of the external field for non-circular tokamak with multipole moment expansion approach

    SciTech Connect

    Okada, O.; DeLucia, J.; Okabayashi, M.

    1980-10-01

    An analytical study is made of the external field required to produce non-circular toroidal MHD equilibria. Here the external magnetic flux pattern is formulated with a series of multipole moments expanded around the magnetic axis. The present approach provides a common description of the external field characteristics of various devices rather than specifying location of poloidal coils. Furthermore, the preconceptual design of noncircular devices can be simplified since the arrangement of poloidal coil location is decoupled from the physics requirement.

  2. Theoretical performance of solar coronagraphs using sharp-edged or apodized circular external occulters

    NASA Astrophysics Data System (ADS)

    Aime, C.

    2013-10-01

    Context. This study focuses on an instrument able to monitor the corona close to the solar limb. Aims: We study the performance of externally occulted solar coronagraphs. We compute the shape of the umbra and penumbra produced by the occulter at the entrance aperture of the telescope and compare levels of rejection obtained for a circular occulter with a sharp or smooth transmission at the edge. Methods: We show that the umbral pattern in an externally occulted coronagraph can be written as a convolution product between the occulter diffraction pattern and an image of the Sun. We then focus on the analysis to circular symmetric occulters. We first derive an analytical expression using two Lommel series for the Fresnel diffraction pattern produced by a sharp-edged circular occulter. Two different expressions are used for inside and outside the occulter's geometric shadow. We verify that a numerical approach that directly solves the Huygens-Fresnel integral gives the same result. This suggests that the numerical computation can be used for a circular occulter with any variable transmission. Results: With the objective of observing the solar corona a few minutes from limb, a sharp-edged circular occulter of a few meters cannot produce an umbra darker than 10-4 of the direct sunlight. The same occulter, having an apodization zone of a few percent of the diameter (3 cm for a 1.5 m occulter), darkers the umbra down to 10-8 of the direct sunlight for linear transmission and to 10-12 for Sonine or cosine bell transmissions. An investigation for an apodized occulter with manufacturing defaults is quickly performed. Conclusions: It has been possible to numerically demonstrate the large superiority of apodized circular occulters with respect to the sharp-edged ones. These occulters allow the theoretical observation of the very limb-close corona with not yet obtained contrast ratios.

  3. Two-dimensional radial laser scanning for circular marker detection and external mobile robot tracking.

    PubMed

    Teixidó, Mercè; Pallejà, Tomàs; Font, Davinia; Tresanchez, Marcel; Moreno, Javier; Palacín, Jordi

    2012-01-01

    This paper presents the use of an external fixed two-dimensional laser scanner to detect cylindrical targets attached to moving devices, such as a mobile robot. This proposal is based on the detection of circular markers in the raw data provided by the laser scanner by applying an algorithm for outlier avoidance and a least-squares circular fitting. Some experiments have been developed to empirically validate the proposal with different cylindrical targets in order to estimate the location and tracking errors achieved, which are generally less than 20 mm in the area covered by the laser sensor. As a result of the validation experiments, several error maps have been obtained in order to give an estimate of the uncertainty of any location computed. This proposal has been validated with a medium-sized mobile robot with an attached cylindrical target (diameter 200 mm). The trajectory of the mobile robot was estimated with an average location error of less than 15 mm, and the real location error in each individual circular fitting was similar to the error estimated with the obtained error maps. The radial area covered in this validation experiment was up to 10 m, a value that depends on the radius of the cylindrical target and the radial density of the distance range points provided by the laser scanner but this area can be increased by combining the information of additional external laser scanners. PMID:23443390

  4. Two-Dimensional Radial Laser Scanning for Circular Marker Detection and External Mobile Robot Tracking

    PubMed Central

    Teixidó, Mercè; Pallejà, Tomàs; Font, Davinia; Tresanchez, Marcel; Moreno, Javier; Palacín, Jordi

    2012-01-01

    This paper presents the use of an external fixed two-dimensional laser scanner to detect cylindrical targets attached to moving devices, such as a mobile robot. This proposal is based on the detection of circular markers in the raw data provided by the laser scanner by applying an algorithm for outlier avoidance and a least-squares circular fitting. Some experiments have been developed to empirically validate the proposal with different cylindrical targets in order to estimate the location and tracking errors achieved, which are generally less than 20 mm in the area covered by the laser sensor. As a result of the validation experiments, several error maps have been obtained in order to give an estimate of the uncertainty of any location computed. This proposal has been validated with a medium-sized mobile robot with an attached cylindrical target (diameter 200 mm). The trajectory of the mobile robot was estimated with an average location error of less than 15 mm, and the real location error in each individual circular fitting was similar to the error estimated with the obtained error maps. The radial area covered in this validation experiment was up to 10 m, a value that depends on the radius of the cylindrical target and the radial density of the distance range points provided by the laser scanner but this area can be increased by combining the information of additional external laser scanners. PMID:23443390

  5. CIRCULAR EXTERNAL FIXATOR PLACEMENT FOR REPAIR OF AN OPEN DISTAL TARSOMETATARSAL FRACTURE IN AN AFRICAN SACRED IBIS (THRESKIORNIS AETHIOPICUS).

    PubMed

    Kinney, Matthew E; Gorse, Mary Jean; Anderson, Mark A

    2015-12-01

    An adult male African sacred ibis (Threskiornis aethiopicus) was diagnosed with an open right distal tarsometatarsal fracture on physical examination and radiographs. External coaptation in the form of an L splint failed to stabilize the fracture appropriately and additional fixation options were explored. The location of the fracture near the articulation between the tarsometatarsus and the hallux, the short distal fracture segment, and decreased viability of the foot precluded the use of previously described fixation methods for tarsometatarsal fracture repair. A three-ring external fixator system with modification to the distal-most ring allowed for postoperative weight-bearing with minimal nursing care. The fixator was removed after 41 days, and the bird remained fully weight-bearing. The use of a circular external fixator for distal tarsometatarsal repair in long-legged birds may be a viable option when full return to function with minimal postoperative care is desired. PMID:26667561

  6. Method for melting glass by measurement of non-bridging oxygen

    DOEpatents

    Jantzen, Carol M.

    1992-01-01

    A method for making better quality molten glass in a glass melter, the glass having the desired viscosity and, preferably, also the desired resistivity so that the glass melt can be established effectively and the product of the glass melter will have the desired level of quality. The method includes the adjustment of the composition of the glass constituents that are fed into the melter in accordance with certain correlations that reliably predict the viscosity and resistivity from the melter temperature and the melt composition, then heating the ingredients to the melter's operating temperature until they melt and homogenize. The equations include the calculation of a "non-bridging oxygen" term from the numbers of moles of the various ingredients, and then the determination of the viscosity and resistivity from the operating temperature of the melter and the non-bridging oxygen term.

  7. Method for melting glass by measurement of non-bridging oxygen

    DOEpatents

    Jantzen, C.M.

    1992-04-07

    A method is described for making better quality molten glass in a glass melter, the glass having the desired viscosity and, preferably, also the desired resistivity so that the glass melt can be established effectively and the product of the glass melter will have the desired level of quality. The method includes the adjustment of the composition of the glass constituents that are fed into the melter in accordance with certain correlations that reliably predict the viscosity and resistivity from the melter temperature and the melt composition, then heating the ingredients to the melter's operating temperature until they melt and homogenize. The equations include the calculation of a non-bridging oxygen' term from the numbers of moles of the various ingredients, and then the determination of the viscosity and resistivity from the operating temperature of the melter and the non-bridging oxygen term. 4 figs.

  8. Externalities.

    ERIC Educational Resources Information Center

    Zicht, Barbara, Ed.; And Others

    1982-01-01

    This issue explains the concept of externalities (benefits or burdens which accrue to society when there is a difference between the private cost or benefit of an action and the social cost or benefit of that action). These external or social costs of individual actions are often referred to as spillover costs. Three brief teaching units follow…

  9. Influence of fluorine on the fiber resistance studied through the nonbridging oxygen hole center related luminescence

    SciTech Connect

    Vaccaro, L.; Cannas, M.; Alessi, A.; Boscaino, R.; Girard, S.; Boukenter, A.; Ouerdane, Y.; Morana, A.

    2013-05-21

    The distribution of Non-Bridging Oxygen Hole Centers (NBOHCs) in fluorine doped optical fibers was investigated by confocal microluminescence spectroscopy, monitoring their characteristic 1.9 eV luminescence band. The results show that these defects are generated by the fiber drawing and their concentration further increases after {gamma} irradiation. The NBOHC concentration profile along the fiber provides evidence for an exponential decay with the fluorine content. This finding agrees with the role of fluorine in the fiber resistance and is discussed, from the microscopic point of view, by looking at the conversion mechanisms from strained bonds acting as precursors.

  10. Control of wake and vortex shedding behind a porous circular obstacle by exerting an external magnetic field

    NASA Astrophysics Data System (ADS)

    Bovand, M.; Rashidi, S.; Dehghan, M.; Esfahani, J. A.; Valipour, M. S.

    2015-07-01

    In this article the finite volume method (FVM) is carried out to simulate the flow around and through a two-dimensional porous cylinder. An external magnetic field is used to control the wake behind the bluff body and also to suppress the vortex shedding phenomena. The Darcy-Brinkman-Forchheimer model has been used for modeling the flow in the porous medium. Effects of Stuart (N), Reynolds (Re) and Darcy (Da) numbers on the flow behavior have been investigated. The results show that the critical Stuart number for suppress vortex shedding decreases with increasing the Darcy numbers. Also, the Stuart number for disappearance the re-circulating wake increases with increased Reynolds number for both porous and solid cylinders.

  11. Luminescence of non-bridging oxygen hole centers in crystalline SiO{sub 2}

    SciTech Connect

    Skuja, Linards Grube, Jurgis; Kajihara, Koichi; Hosono, Hideo

    2014-10-21

    Oxygen dangling bonds (nonbridging oxygen hole centers, NBOHCs), which are characteristic to amorphous SiO{sub 2}, were studied in amorphized regions of neutron-irradiated α-quartz crystal and on their boundaries by time-resolved site-selective photoluminescence (PL) at 20K. Along with the usual disorder-broadened PL band of NBOHCs, sharp, 'crystal-like' zero-phonon lines (ZPLs), whose positions do not shift with the excitation wavelength, are observed. In addition to the previously reported NBOHCs with ZPL at 1.933 eV, a second sub-type of NBOHCs with ZPL at 1.883 eV is confirmed by observation of its vibrational sideband due to Si-(dangling O) stretching mode (897cm{sup −1}) under resonance 1.883eV excitation. A third sub-type of NBOHCs with an excitation energy at 1.879 eV, distinguished by a strong coupling to low-energy (66 cm{sup −1}) vibrational mode is found. This mode is weakly coupled also to the other two sub-types of NBOHCs.

  12. Striking role of non-bridging oxygen on glass transition temperature of calcium aluminosilicate glass-formers

    SciTech Connect

    Bouhadja, M.; Jakse, N.; Pasturel, A.

    2014-06-21

    Molecular dynamics simulations are used to study the structural and dynamic properties of calcium aluminosilicate, (CaO-Al{sub 2}O{sub 3}){sub 1−x}(SiO{sub 2}){sub x}, glass formers along three joins, namely, R = 1, 1.57, and 3, in which the silica content x can vary from 0 to 1. For all compositions, we determined the glass-transition temperature, the abundances of the non-bridging oxygen, triclusters, and AlO{sub 5} structural units, as well as the fragility from the temperature evolution of the α-relaxation times. We clearly evidence the role played by the non-bridging oxygen linked either to Al atoms or Si atoms in the evolution of the glass-transition temperature as well as of the fragility as a function of silica content along the three joins.

  13. The use of a circular external skeletal fixation device for the management of long bone osteotomies in large ruminants: an experimental study.

    PubMed

    Aithal, H P; Singh, G R; Hoque, M; Maiti, S K; Kinjavdekar, P; Pawde, A M; Setia, H C

    2004-08-01

    The study was undertaken to evaluate the feasibility of a simple, inexpensive model of circular external fixator (CEF) for use in large ruminants. A simple model of CEF frames consisting of four full rings (13-19 cm diameter, 4 cm wide and 4 mm thick with 18-24 holes) connected by threaded rods (8 mm diameter, 10-15 cm long) and nuts was developed using mild (low carbon) steel and were nickel-plated. In the first phase of the study, three male cow calves were utilized to study the feasibility of application of the fixators in the metatarsus, tibia and radius, in reference of adaptation and tolerance by animals. In the second phase, the fixators were tested in osteotomized bones. Six bull calves of 1.5-2 years of age weighing about 200-250 kg were utilized for this purpose. After preparing the area for aseptic surgery, under xylazine (at 0.1 mg/kg, i.m.)-ketamine (i.v. till effect) general anaesthesia, the test bone (metatarsus, radius and tibia in two animals each) was approached through the medial surface and an osteotomy was created with a saw and chisel at the mid-diaphysis. The pre-constructed 4-ring CEF was mounted on the limb around the test bone in such a way that it formed a cylinder with the axis of the limb at the centre. Each ring was then fixed to the bone with a pair of beaded wires (316 SS) of 3.5 mm diameter. During the post-operative period, the animals were observed for any change in behaviour, tolerance of the fixators, the weight bearing on the test limb, the status of the fixator, and the level of reduction of the osteotomy, alignment and healing at different intervals. The fixation of CEF was easier in the metatarsus and radius than in the tibia. The inner ring diameters found adequate for metatarsus, radius and tibia were 13-15 cm, 15-17 cm and 17-19 cm, respectively. The fixators applied to different bones were well-tolerated, and the animals could lay down, stand and walk freely with the fixator without any problems. All the animals showed

  14. Non-bridging Oxygens in Calcium Aluminosilicate Glass From Per-calcic to Peraluminous Compositions

    NASA Astrophysics Data System (ADS)

    Thompson, L.; Stebbins, J.

    2008-12-01

    The role of non-bridging oxygen (NBO) and its effects on the thermodynamic and transport properties of aluminosilicate melts are not fully understood, although this species clearly must have a major influence on configurational entropy, viscosity, etc. Its existence along metaluminous joins in alkali- and alkaline-earth aluminosilicates was first postulated from viscosity measurements (Toplis et al., 1996, 2004) and then directly observed in several metaluminous calcium aluminosilicates by 17O nuclear magnetic resonance (NMR) spectroscopy. Much of the recent work has concentrated on glasses with an M+n/(M+nAl) ratio greater than or equal to 0.5 (metaluminous to peralkaline or per-alkaline earth); however, the observed viscosity maxima in several ternary systems occur when this ratio is less than 0.5 (peraluminous). Using NMR spectroscopy, this study investigates the effects of the Ca/Al ratio on the amount of NBO present in calcium aluminosilicate (CAS) glasses. 17O MAS NMR spectra of glasses with 60 mol% SiO2 show a decrease in NBO as the ratio R=Ca+2/(Ca+2Al) decreases, from 6.9% at R=0.56 to 1.0% at R=0.44. Measurable amounts of NBO thus persist well into the peraluminous region of the CAS system, but the species becomes undetectable (<0.5%) when R reaches 0.38 and 0.33. 27Al MAS NMR spectra of these glasses show an increase in the amount of five-coordinated aluminum as compositions become more peraluminous, as is well-known from previous studies (Neuville et al. 2006). Comparison with published viscosity measurements measured at both higher and lower mol % SiO2 (Toplis et al. 2004) suggests that the viscosity maximum does not correspond exactly with the disappearance of NBO from the glasses, but effects of temperature on speciation will need to be taken into account to accurately link glass structure with melt properties: recent work has shown, for example, that NBO content increases with temperature in CaAl2Si2O8 melt (Stebbins et al. 2008).

  15. Circular Coinduction

    NASA Technical Reports Server (NTRS)

    Rosu, Grigore; Goguen, Joseph; Norvig, Peter (Technical Monitor)

    2001-01-01

    Circular coinduction is a technique for behavioral reasoning that extends cobasis coinduction to specifications with circularities. Because behavioral satisfaction is not recursively enumerable, no algorithm can work for every behavioral statement. However. algorithms using circular coinduction can prove every practical behavioral result that we know. This paper proves the correctness of circular coinduction and some consequences.

  16. External fixation of distal radius fractures.

    PubMed

    Slutsky, David J

    2007-12-01

    External fixation has been used for the treatment of distal radius fractures for more than 50 years. Although the fixator configurations have undergone considerable modification over time, the type of fixator itself is not as important as the underlying principles that provide the foundation for external fixation. Although volar plate fixation is currently in vogue, the indications for external fixation remain largely unchanged. Newer fixator designs have also expanded the traditional usage to include nonbridging applications that allow early wrist motion. The following discussion focuses on the myriad uses for external fixation as well as the shortcomings and potential pitfalls. PMID:18070654

  17. Relations among nonbridging oxygen, optical properties, optical basicity, and color center formation in CaO-MgO aluminosilicate glasses

    SciTech Connect

    Novatski, A.; Steimacher, A.; Medina, A. N.; Bento, A. C.; Baesso, M. L.; Andrade, L. H. C.; Lima, S. M.; Guyot, Y.; Boulon, G.

    2008-11-01

    In this study the relations among nonbridging oxygen (NBO), optical properties, optical basicity, and color center formation in CaO-MgO aluminosilicate glasses were studied. Samples containing (in mol %) 35.9-57.5 of CaO, 16-27.7 of Al{sub 2}O{sub 3}, 7.9-41.6 of SiO{sub 2}, and 6.5-6.9 of MgO were measured by optical absorption and excitation, luminescence, and Raman spectroscopy. The results showed that when the SiO{sub 2} content was increased, the absorption edge shifted toward lower wavelengths and the bonds between O{sup 2-} ions and cations became more covalent. These observations were confirmed by Raman results that showed a decrease in the number of NBO per silicon tetrahedron as a function of SiO{sub 2} content. The results indicate that the effects of higher NBO concentration are the narrowing of the band gap energy and the delocalization of O{sup 2-} electrons, which facilitates the O{sup 2-} electrons to be trapped by anion vacancies and, consequently, forming color centers. The relationship between color center formation and SiO{sub 2} content was confirmed by optical spectroscopic measurements under UV radiation.

  18. Circular motion

    NASA Astrophysics Data System (ADS)

    Newton, Isaac; Henry, Richard Conn

    2000-07-01

    An extraordinarily simple and transparent derivation of the formula for the acceleration that occurs in uniform circular motion is presented, and is advocated for use in high school and college freshman physics textbooks.

  19. Circular inferences in schizophrenia.

    PubMed

    Jardri, Renaud; Denève, Sophie

    2013-11-01

    A considerable number of recent experimental and computational studies suggest that subtle impairments of excitatory to inhibitory balance or regulation are involved in many neurological and psychiatric conditions. The current paper aims to relate, specifically and quantitatively, excitatory to inhibitory imbalance with psychotic symptoms in schizophrenia. Considering that the brain constructs hierarchical causal models of the external world, we show that the failure to maintain the excitatory to inhibitory balance results in hallucinations as well as in the formation and subsequent consolidation of delusional beliefs. Indeed, the consequence of excitatory to inhibitory imbalance in a hierarchical neural network is equated to a pathological form of causal inference called 'circular belief propagation'. In circular belief propagation, bottom-up sensory information and top-down predictions are reverberated, i.e. prior beliefs are misinterpreted as sensory observations and vice versa. As a result, these predictions are counted multiple times. Circular inference explains the emergence of erroneous percepts, the patient's overconfidence when facing probabilistic choices, the learning of 'unshakable' causal relationships between unrelated events and a paradoxical immunity to perceptual illusions, which are all known to be associated with schizophrenia. PMID:24065721

  20. Characterization of Circular RNAs.

    PubMed

    Zhang, Yang; Yang, Li; Chen, Ling-Ling

    2016-01-01

    Accumulated lines of evidence reveal that a large number of circular RNAs are produced in transcriptomes from fruit fly to mouse and human. Unlike linear RNAs shaped with 5' cap and 3' tail, circular RNAs are characterized by covalently closed loop structures without open terminals, thus requiring specific treatments for their identification and validation. Here, we describe a detailed pipeline for the characterization of circular RNAs. It has been successfully applied to the study of circular intronic RNAs derived from intron lariats (ciRNAs) and circular RNAs produced from back spliced exons (circRNAs) in human. PMID:26721494

  1. Circularly polarized waves in a plasma with vacuum polarization effects

    SciTech Connect

    Lundin, J.; Stenflo, L.; Brodin, G.; Marklund, M.; Shukla, P. K.

    2007-06-15

    The theory for large amplitude circularly polarized waves propagating along an external magnetic field is extended in order to also include vacuum polarization effects. A general dispersion relation, which unites previous results, is derived.

  2. Toroidal circular dichroism

    NASA Astrophysics Data System (ADS)

    Raybould, T. A.; Fedotov, V. A.; Papasimakis, N.; Kuprov, I.; Youngs, I. J.; Chen, W. T.; Tsai, D. P.; Zheludev, N. I.

    2016-07-01

    We demonstrate that the induced toroidal dipole, represented by currents flowing on the surface of a torus, makes a distinct and indispensable contribution to circular dichroism. We show that toroidal circular dichroism supplements the well-known mechanism involving electric dipole and magnetic dipole transitions. We illustrate this with rigorous analysis of the experimentally measured polarization-sensitive transmission spectra of an artificial metamaterial, constructed from elements of toroidal symmetry. We argue that toroidal circular dichroism will be found in large biomolecules with elements of toroidal symmetry and should be taken into account in the interpretation of circular dichroism spectra of organics.

  3. Bonding Preferences of Non-Bridging Oxygens in Calcium Aluminosilicate Glass: Evidence from O-17 MAS and 3QMAS NMR on Calcium Aluminate Glass

    NASA Astrophysics Data System (ADS)

    Allwardt, J. R.; Lee, S.; Stebbins, J.

    2001-12-01

    Non-bridging oxygens (NBO's) play a significant role in the thermodynamic and transport properties in glasses and silicate melts. Previous oxygen-17 (O-17) triple quantum magic angle spinning (3QMAS NMR) data have shown the presence of NBO's in several calcium aluminosilicate (CAS) glasses on the CaAl2O4-SiO2 join (Stebbins and Xu 1997). The observed chemical shifts of these glasses are similar to those for the NBO in calcium silicate glasses (Stebbins et al. 1997 and Stebbins et al 1999); however, a recent O-17 MAS NMR study of crystalline CaAl2O4 showed that the NBO peak in an associated impurity phase is shifted to a higher frequency by 30 to 40 ppm from that of CAS and Ca-silicate glasses (Stebbins et al. in press). This finding suggests that Si is the preferred network cation for NBO's in aluminosilicate glasses and melts at the glass transition temperature. The preference for Si over that of Al as the network cation host for NBO's has also been suggested by Raman and other spectroscopic techniques (Mysen 1988). To investigate this apparent preference for Si-NBO, O-17 3QMAS and MAS experiments were conducted to examine the location of the NBO peak in the spectra of a calcium aluminate glass. Since the CaAl2O4 glass is difficult to make by conventional cooling methods, the binary eutectic composition (63CaO-37Al2O3) was chosen. The resulting O-17 MAS spectrum shows an intense, relatively narrow peak centered at 72 ppm, which nearly coincides with the peak location and width of the Al-O-Al peak in the crystalline Ca-aluminates (Stebbins et al. in press.) (70 ppm). There is a broader, less intense peak centered at 155 ppm that is assigned to the Al-NBO peak. This peak is in approximately the same location as that for a Ca-aluminate phase reported by Stebbins et al. (in press) (137 ppm). In addition, our 3QMAS data show that the peak maximum of the NBO in the Ca-aluminate (-85 and 150 ppm in isotropic and MAS dimensions, respectively) differs significantly from

  4. 2. Northwest circular bastion, seen from edge of southwest circular ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Northwest circular bastion, seen from edge of southwest circular bastion wall. Metal roof beams extend up to form peak. World War II gun installation at right. - Fort Hamilton, Northwest Circular Bastion, Rose Island, Newport, Newport County, RI

  5. Squaring a Circular Segment

    ERIC Educational Resources Information Center

    Gordon, Russell

    2008-01-01

    Consider a circular segment (the smaller portion of a circle cut off by one of its chords) with chord length c and height h (the greatest distance from a point on the arc of the circle to the chord). Is there a simple formula involving c and h that can be used to closely approximate the area of this circular segment? Ancient Chinese and Egyptian…

  6. Tunable circular patch antennas

    NASA Astrophysics Data System (ADS)

    Lan, G.-L.; Sengupta, D. L.

    1985-10-01

    A method to control the resonant or operating frequencies of circular patch antennas has been investigated experimentally and theoretically. It consists of the placement of passive metallic or tuning posts at approximate locations within the input region of the antenna. Comparison of measured and analytical results seems to establish the validity of a theoretical model proposed to determine the input performance of such circular patch antennas.

  7. Circular free-electron laser

    DOEpatents

    Brau, Charles A.; Kurnit, Norman A.; Cooper, Richard K.

    1984-01-01

    A high efficiency, free electron laser utilizing a circular relativistic electron beam accelerator and a circular whispering mode optical waveguide for guiding optical energy in a circular path in the circular relativistic electron beam accelerator such that the circular relativistic electron beam and the optical energy are spatially contiguous in a resonant condition for free electron laser operation. Both a betatron and synchrotron are disclosed for use in the present invention. A free electron laser wiggler is disposed around the circular relativistic electron beam accelerator for generating a periodic magnetic field to transform energy from the circular relativistic electron beam to optical energy.

  8. Compact waveguide circular polarizer

    DOEpatents

    Tantawi, Sami G.

    2016-08-16

    A multi-port waveguide is provided having a rectangular waveguide that includes a Y-shape structure with first top arm having a first rectangular waveguide port, a second top arm with second rectangular waveguide port, and a base arm with a third rectangular waveguide port for supporting a TE.sub.10 mode and a TE.sub.20 mode, where the end of the third rectangular waveguide port includes rounded edges that are parallel to a z-axis of the waveguide, a circular waveguide having a circular waveguide port for supporting a left hand and a right hand circular polarization TE.sub.11 mode and is coupled to a base arm broad wall, and a matching feature disposed on the base arm broad wall opposite of the circular waveguide for terminating the third rectangular waveguide port, where the first rectangular waveguide port, the second rectangular waveguide port and the circular waveguide port are capable of supporting 4-modes of operation.

  9. Copyright Basics. Circular 1.

    ERIC Educational Resources Information Center

    Library of Congress, Washington, DC. Copyright Office.

    This circular answers some of the questions that are frequently asked about copyright, a form of protection provided by the laws of the United States to authors of "original works of authorship" including library, dramatic musical, artistic, and certain other intellectual works. The Copyright Act of 1976 (title 17 of the United States Code), which…

  10. Wiimote Experiments: Circular Motion

    ERIC Educational Resources Information Center

    Kouh, Minjoon; Holz, Danielle; Kawam, Alae; Lamont, Mary

    2013-01-01

    The advent of new sensor technologies can provide new ways of exploring fundamental physics. In this paper, we show how a Wiimote, which is a handheld remote controller for the Nintendo Wii video game system with an accelerometer, can be used to study the dynamics of circular motion with a very simple setup such as an old record player or a…

  11. Wiimote Experiments: Circular Motion

    NASA Astrophysics Data System (ADS)

    Kouh, Minjoon; Holz, Danielle; Kawam, Alae; Lamont, Mary

    2013-03-01

    The advent of new sensor technologies can provide new ways of exploring fundamental physics. In this paper, we show how a Wiimote, which is a handheld remote controller for the Nintendo Wii video game system with an accelerometer, can be used to study the dynamics of circular motion with a very simple setup such as an old record player or a bicycle wheel.

  12. Electron capture from circular Rydberg atoms

    SciTech Connect

    Hansen, S.B.; Ehrenreich, T.; Horsdal-Pedersen, E. ); MacAdam, K.B. ); Dube, L.J. )

    1993-09-06

    Capture cross sections for circular Rydberg states have been measured as a function of the angle, [ital cphi], between ion velocity and angular momentum of the circular orbital. The system studied is 2.5 keV [sup 23]Na[sup +] on Li(1[ital s][sup 2],[ital nlm]) with [ital n]=25, [ital l]=[ital n][minus]1, and [ital m]=+[ital l], where [ital m] is defined relative to a weak, external magnetic field. A strong dependence on [ital cphi] is found. It is expected that studies such as the present will lead to an improved understanding of the three-body problem in the region of sufficiently large quantum numbers and impact velocities for classical physics to be accurate.

  13. Switchable circular beam deflectors

    NASA Astrophysics Data System (ADS)

    Shang, Xiaobing; Joshi, Pankaj; Tan, Jin-Yi; De Smet, Jelle; Cuypers, Dieter; Baghdasaryan, Tigran; Vervaeke, Michael; Thienpont, Hugo; De Smet, Herbert

    2016-04-01

    In this work, we report two types of electrically tunable photonic devices with circularly symmetric polarization independent beam steering performance (beam condensing resp. beam broadening). The devices consist of circular micro grating structures combined with nematic liquid crystal (LC) layers with anti-parallel alignment. A single beam deflector converts a polarized and monochromatic green laser beam (λ =543.5 nm) into a diffraction pattern, with the peak intensity appearing at the third order when 0~{{V}\\text{pp}} is applied and at the zeroth order (no deflection) for voltages above 30~{{V}\\text{pp}} . Depending on the shape of the grating structure (non-inverted or inverted), the deflection is inwards or outwards. Both grating types can be made starting from the same diamond-tooled master mold. A polarized white light beam is symmetrically condensed resp. broadened over 2° in the off state and is passed through unchanged in the on state. By stacking two such devices with mutually orthogonal LC alignment layers, polarization independent switchable circular beam deflectors are realized with a high transmittance (>80%), and with the same beam steering performance as the polarization dependent single devices.

  14. Multipole Analysis of Circular Cylindircal Magnetic Systems

    SciTech Connect

    J Selvaggi

    2006-01-09

    This thesis deals with an alternate method for computing the external magnetic field from a circular cylindrical magnetic source. The primary objective is to characterize the magnetic source in terms of its equivalent multipole distribution. This multipole distribution must be valid at points close to the cylindrical source and a spherical multipole expansion is ill-equipped to handle this problem; therefore a new method must be introduced. This method, based upon the free-space Green's function in cylindrical coordinates, is developed as an alternative to the more familiar spherical harmonic expansion. A family of special functions, called the toroidal functions or Q-functions, are found to exhibit the necessary properties for analyzing circular cylindrical geometries. In particular, the toroidal function of zeroth order, which comes from the integral formulation of the free-space Green's function in cylindrical coordinates, is employed to handle magnetic sources which exhibit circular cylindrical symmetry. The toroidal functions, also called Q-functions, are the weighting coefficients in a ''Fourier series-like'' expansion which represents the free-space Green's function. It is also called a toroidal expansion. This expansion can be directly employed in electrostatic, magnetostatic, and electrodynamic problems which exhibit cylindrical symmetry. Also, it is shown that they can be used as an alternative to the Elliptic integral formulation. In fact, anywhere that an Elliptic integral appears, one can replace it with its corresponding Q-function representation. A number of problems, using the toroidal expansion formulation, are analyzed and compared to existing known methods in order to validate the results. Also, the equivalent multipole distribution is found for most of the solved problems along with its corresponding physical interpretation. The main application is to characterize the external magnetic field due to a six-pole permanent magnet motor in terms of

  15. Condensation of circular DNA

    NASA Astrophysics Data System (ADS)

    Starostin, E. L.

    2013-04-01

    A simple model of a circularly closed double-stranded DNA in a poor solvent is considered as an example of a semi-flexible polymer with self-attraction. To find the ground states, the conformational energy is computed as a sum of the bending and torsional elastic components and the effective self-attraction energy. The model includes a relative orientation or sequence dependence of the effective attraction forces between different pieces of the polymer chain. Two series of conformations are analysed: a multicovered circle (a toroid) and a multifold two-headed racquet. The results are presented as a diagram of state. It is suggested that the stability of particular conformations may be controlled by proper adjustment of the primary structure. Application of the model to other semi-flexible polymers is considered.

  16. CIRCULAR CAVITY SLOT ANTENNA

    DOEpatents

    Kerley, P.L.

    1959-01-01

    A small-size antenna having a doughnut-shaped field pattern and which can act both as an antenna and a resonant circuit is described. The antenna is of the slotted type and comprises a resonant cavity with a center hole. A circular slot is provided in one wall of the cavity concentric with the hole and a radio frequency source is connected across the slot. The pattern and loading of the antenna are adjusted by varying the position and shape of a center element slidably disposed within the hole and projecting from the slotted side of the resonant cavity. The disclosed structure may also be used to propagate the oscillator signal down a transniission line by replacing the center element with one leg of the transmission line in a spaced relation from the walls of the cavity.

  17. Children's Sensitivity to Circular Explanations

    ERIC Educational Resources Information Center

    Baum, Laura A.; Danovitch, Judith H.; Keil, Frank C.

    2008-01-01

    The ability to evaluate the quality of explanations is an essential part of children's intellectual growth. Explanations can be faulty in structural ways such as when they are circular. A circular explanation reiterates the question as if it were an explanation rather than providing any new information. Two experiments (N=77) examined children's…

  18. Circular chemiresistors for microchemical sensors

    DOEpatents

    Ho, Clifford K.

    2007-03-13

    A circular chemiresistor for use in microchemical sensors. A pair of electrodes is fabricated on an electrically insulating substrate. The pattern of electrodes is arranged in a circle-filling geometry, such as a concentric, dual-track spiral design, or a circular interdigitated design. A drop of a chemically sensitive polymer (i.e., chemiresistive ink) is deposited on the insulating substrate on the electrodes, which spreads out into a thin, circular disk contacting the pair of electrodes. This circularly-shaped electrode geometry maximizes the contact area between the pair of electrodes and the polymer deposit, which provides a lower and more stable baseline resistance than with linear-trace designs. The circularly-shaped electrode pattern also serves to minimize batch-to-batch variations in the baseline resistance due to non-uniform distributions of conductive particles in the chemiresistive polymer film.

  19. Circular Bioassay Platforms for Applications in Microwave-Accelerated Techniques

    PubMed Central

    Mohammed, Muzaffer; Clement, Travis C.; Aslan, Kadir

    2014-01-01

    In this paper, we present the design of four different circular bioassay platforms, which are suitable for homogeneous microwave heating, using theoretical calculations (i.e., COMSOL™ multiphysics software). Circular bioassay platforms are constructed from poly(methyl methacrylate) (PMMA) for optical transparency between 400–800 nm, has multiple sample capacity (12, 16, 19 and 21 wells) and modified with silver nanoparticle films (SNFs) to be used in microwave-accelerated bioassays (MABs). In addition, a small monomode microwave cavity, which can be operated with an external microwave generator (100 W), for use with the bioassay platforms in MABs is also developed. Our design parameters for the circular bioassay platforms and monomode microwave cavity during microwave heating were: (i) temperature profiles, (ii) electric field distributions, (iii) location of the circular bioassay platforms inside the microwave cavity, and (iv) design and number of wells on the circular bioassay platforms. We have also carried out additional simulations to assess the use of circular bioassay platforms in a conventional kitchen microwave oven (e.g., 900 W). Our results show that the location of the circular bioassay platforms in the microwave cavity was predicted to have a significant effect on the homogeneous heating of these platforms. The 21-well circular bioassay platform design in our monomode microwave cavity was predicted to offer a homogeneous heating pattern, where inter-well temperature was observed to be in between 23.72–24.13°C and intra-well temperature difference was less than 0.21°C for 60 seconds of microwave heating, which was also verified experimentally. PMID:25568813

  20. Buckling of elliptical rings under uniform external pressure

    SciTech Connect

    Tang, Y.

    1991-04-03

    A thin, elastic elliptical ring is subjected to uniform external pressure. The lowest critical pressure is computed and presented for various ratio of the major axis to the minor axis of the elliptical ring. It is found that the critical pressure for an elliptical ring is higher than that for the circular ring whose diameter is equal to the major axis of the elliptical ring. It can be shown that under the same external pressure, the axial force developed in the elliptical ring is less than that developed in the corresponding circular ring. Thus, a higher pressure is required to buckle the elliptical rings. Therefore, by changing the shape of the ring from circular to elliptical, the capability of the ring to sustain the external pressure can be increased substantially. The results of this study can be useful in the design of elliptical reinforcing rings and thin-walled tubes subjected to external pressure.

  1. Nuclear spin circular dichroism

    SciTech Connect

    Vaara, Juha; Rizzo, Antonio; Kauczor, Joanna; Norman, Patrick; Coriani, Sonia

    2014-04-07

    Recent years have witnessed a growing interest in magneto-optic spectroscopy techniques that use nuclear magnetization as the source of the magnetic field. Here we present a formulation of magnetic circular dichroism (CD) due to magnetically polarized nuclei, nuclear spin-induced CD (NSCD), in molecules. The NSCD ellipticity and nuclear spin-induced optical rotation (NSOR) angle correspond to the real and imaginary parts, respectively, of (complex) quadratic response functions involving the dynamic second-order interaction of the electron system with the linearly polarized light beam, as well as the static magnetic hyperfine interaction. Using the complex polarization propagator framework, NSCD and NSOR signals are obtained at frequencies in the vicinity of optical excitations. Hartree-Fock and density-functional theory calculations on relatively small model systems, ethene, benzene, and 1,4-benzoquinone, demonstrate the feasibility of the method for obtaining relatively strong nuclear spin-induced ellipticity and optical rotation signals. Comparison of the proton and carbon-13 signals of ethanol reveals that these resonant phenomena facilitate chemical resolution between non-equivalent nuclei in magneto-optic spectra.

  2. Bending and buckling behavior analysis of foamed metal circular plate.

    PubMed

    Fan, Jian Ling; Ma, Lian Sheng; Zhang, Lu; De Su, Hou

    2016-01-01

    This paper establishes a density gradient model along the thickness direction of a circular plate made of foamed material. Based on the first shear deformation plate theory, the result is deduced that the foamed metal circular plate with graded density along thickness direction yields axisymmetric bending problem under the action of uniformly distributed load, and the analytical solution is obtained by solving the governing equation directly. The analyses on two constraint conditions of edge radial clamping and simply supported show that the density gradient index and external load may affect the axisymmetric bending behavior of the plate. Then, based on the classical plate theory, the paper analyzes the behavior of axisymmetric buckling under radial pressure applied on the circular plate. Shooting method is used to obtain the critical load, and the effects of gradient nature of material properties and boundary conditions on the critical load of the plate are analyzed. PMID:27339281

  3. Circular Scan Streak Tube Development

    NASA Technical Reports Server (NTRS)

    Nevin, S.

    1980-01-01

    A streak tube having circular scan was designed, built and tested. Continuous circular scan, easily derived from out of phase sine waves applied to the conventional deflection plates, permits the timing of pulses traveling long baselines. At the tube's output a circular array of 720 elements is scanned to provide 30 to 40 picosecond resolution. Initial difficulties with electron bombarded silicon arrays were circumvented by using microchannel plates within the streak tube to provide the needed electronic amplification and digital sensitivity and coupling the 720 element arrays to the electron beam by means of a phosphor on a fiber optics. Two ceramic body tubes with S-20 photocathodes were tested and delivered.

  4. Beam Rounders for Circular Colliders

    SciTech Connect

    A. Burov; S. Nagaitsev; Ya. Derbenev

    2001-07-01

    By means of linear optics, an arbitrary uncoupled beam can be locally transformed into a round (rotation-invariant) state and then back. This provides an efficient way to round beams in the interaction region of circular colliders.

  5. Circularly-Polarized Microstrip Antenna

    NASA Technical Reports Server (NTRS)

    Stanton, P. H.

    1985-01-01

    Microstrip construction compact for mobile applications. Circularly polarized microstrip antenna made of concentric cylindrical layers of conductive and dielectric materials. Coaxial cable feedlines connected to horizontal and vertical subelements from inside. Vertical subelement acts as ground for horizontal subelement.

  6. Circularization time of binary galaxies

    NASA Astrophysics Data System (ADS)

    Junqueira, S.; de Freitas Pacheco, J. A.

    1994-11-01

    We report the results of numerical experiments performed to study the orbital circularization time of binary galaxies. We find that the time scale is quite long (larger than the Hubble time), confirming earlier calculations. The results depend on the initial conditions. From our simulations we obtained a fitting formula for the circularization time as a function of the initial orbital parameters like the pericentric distance, mass ratio, and eccentricity.

  7. External Beam Therapy (EBT)

    MedlinePlus

    ... Physician Resources Professions Site Index A-Z External Beam Therapy (EBT) External beam therapy (EBT) is a ... follow-up should I expect? What is external beam therapy and how is it used? External beam ...

  8. Circular polarization interferometry: circularly polarized modes of cholesteric liquid crystals.

    PubMed

    Sanchez-Castillo, A; Eslami, S; Giesselmann, F; Fischer, P

    2014-12-15

    We describe a novel polarization interferometer which permits the determination of the refractive indices for circularly-polarized light. It is based on a Jamin-Lebedeff interferometer, modified with waveplates, and permits us to experimentally determine the refractive indices nL and nR of the respectively left- and right-circularly polarized modes in a cholesteric liquid crystal. Whereas optical rotation measurements only determine the circular birefringence, i.e. the difference (nL - nR), the interferometer also permits the determination of their absolute values. We report refractive indices of a cholesteric liquid crystal in the region of selective (Bragg) reflection as a function of temperature. PMID:25607071

  9. Generalized bi-circular projections

    NASA Astrophysics Data System (ADS)

    Lin, Pei-Kee

    2008-04-01

    Recall that a projection P on a complex Banach space X is a generalized bi-circular projection if P+[lambda](I-P) is a (surjective) isometry for some [lambda] such that [lambda]=1 and [lambda][not equal to]1. It is easy to see that every hermitian projection is generalized bi-circular. A generalized bi-circular projection is said to be nontrivial if it is not hermitian. Botelho and Jamison showed that a projection P on C([0,1]) is a nontrivial generalized bi-circular projection if and only if P-(I-P) is a surjective isometry. In this article, we prove that if P is a projection such that P+[lambda](I-P) is a (surjective) isometry for some [lambda], then either P is hermitian or [lambda] is an nth unit root of unity. We also show that for any nth unit root [lambda] of unity, there are a complex Banach space X and a nontrivial generalized bi-circular projection P on X such that P+[lambda](I-P) is an isometry.

  10. Circular codes, symmetries and transformations.

    PubMed

    Fimmel, Elena; Giannerini, Simone; Gonzalez, Diego Luis; Strüngmann, Lutz

    2015-06-01

    Circular codes, putative remnants of primeval comma-free codes, have gained considerable attention in the last years. In fact they represent a second kind of genetic code potentially involved in detecting and maintaining the normal reading frame in protein coding sequences. The discovering of an universal code across species suggested many theoretical and experimental questions. However, there is a key aspect that relates circular codes to symmetries and transformations that remains to a large extent unexplored. In this article we aim at addressing the issue by studying the symmetries and transformations that connect different circular codes. The main result is that the class of 216 C3 maximal self-complementary codes can be partitioned into 27 equivalence classes defined by a particular set of transformations. We show that such transformations can be put in a group theoretic framework with an intuitive geometric interpretation. More general mathematical results about symmetry transformations which are valid for any kind of circular codes are also presented. Our results pave the way to the study of the biological consequences of the mathematical structure behind circular codes and contribute to shed light on the evolutionary steps that led to the observed symmetries of present codes. PMID:25008961

  11. Circular birefringence of banded spherulites.

    PubMed

    Cui, Xiaoyan; Shtukenberg, Alexander G; Freudenthal, John; Nichols, Shane; Kahr, Bart

    2014-04-01

    Crystal optical properties of banded spherulites of 21 different compounds--molecular crystals, polymers, and minerals--with helically twisted fibers were analyzed with Mueller matrix polarimetry. The well-established radial oscillations in linear birefringence of many polycrystalline ensembles is accompanied by oscillations in circular birefringence that cannot be explained by the natural optical activity of corresponding compounds, some of which are centrosymmetric in the crystalline state. The circular birefringence is shown to be a consequence of misoriented, overlapping anisotropic lamellae, a kind of optical activity associated with the mesoscale stereochemistry of the refracting components. Lamellae splay as a consequence of space constraints related to simultaneous twisting of anisometric lamellae. This mechanism is supported by quantitative simulations of circular birefringence arising from crystallite twisting and splaying under confinement. PMID:24625095

  12. Podokinetic circular vection: characteristics and interaction with optokinetic circular vection.

    PubMed

    Becker, W; Kliegl, K; Kassubek, J; Jürgens, R

    2016-07-01

    Stabilising horizontal body orientation in space without sight on a rotating platform by holding to a stationary structure and circular 'treadmill' stepping in the opposite direction can elicit an illusion of self-turning in space (Bles and Kapteyn in Agressologie 18:325-328, 1977). Because this illusion is analogous to the well-known illusion of optokinetic circular vection (oCV), we call it 'podokinetic circular vection' (pCV) here. Previous studies using eccentric stepping on a path tangential to the rotation found that pCV was always contraversive relative to platform rotation. In contrast, when our subjects stepped at the centre of rotation about their vertical axis, we observed an inverted, ipsiversive pCV as a reproducible trait in many of our subjects. This ipCV occurred at the same latency as the pCV of subjects reporting the actually expected contraversive direction, but had lower gain. In contrast to pCV, the nystagmus accompanying circular treadmill stepping had the same direction in all individuals (slow phase in the direction of platform motion). The direction of an individual's pCV predicted the characteristics of the CV resulting from combined opto- and podokinetic stimulation (circular treadmill stepping while viewing a pattern rotating together with the platform): in individuals with contraversive pCV, latency shortened and both gain and felt naturalness increased in comparison with pure oCV, whereas the opposite (longer latency, reduced gain and naturalness) occurred in individuals with ipCV. Taken together, the reproducibility of ipCV, the constant direction of nystagmus and the fact that pCV direction predicts the outcome of combined stimulation suggest that ipCV is an individual trait of many subjects during compensatory stepping at the centre of rotation. A hypothetical model is presented of how ipCV possibly could arise. PMID:26965438

  13. Maximal dinucleotide and trinucleotide circular codes.

    PubMed

    Michel, Christian J; Pellegrini, Marco; Pirillo, Giuseppe

    2016-01-21

    We determine here the number and the list of maximal dinucleotide and trinucleotide circular codes. We prove that there is no maximal dinucleotide circular code having strictly less than 6 elements (maximum size of dinucleotide circular codes). On the other hand, a computer calculus shows that there are maximal trinucleotide circular codes with less than 20 elements (maximum size of trinucleotide circular codes). More precisely, there are maximal trinucleotide circular codes with 14, 15, 16, 17, 18 and 19 elements and no maximal trinucleotide circular code having less than 14 elements. We give the same information for the maximal self-complementary dinucleotide and trinucleotide circular codes. The amino acid distribution of maximal trinucleotide circular codes is also determined. PMID:26382231

  14. 25 CFR 23.46 - Financial management, internal and external controls and other assurances.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... recognized Indian tribal governments). (b) OMB Circular A-102 (Common rule 43 CFR part 12). (c) OMB Circular... organizations and tribal organizations, where applicable). (e) Internal control. Effective control and... 25 Indians 1 2010-04-01 2010-04-01 false Financial management, internal and external controls...

  15. Circular RNA expands its territory.

    PubMed

    Bao, Chunyang; Lyu, Dongbin; Huang, Shenglin

    2016-03-01

    Circular RNAs (circRNAs) represent a novel class of widespread non-coding RNAs in eukaryotes. They are unusually stable RNA molecules with cell type-specific expression patterns, and are predominantly present in the cytoplasm. We recently demonstrated the existence of abundant circRNAs in exosomes and suggest a potential application of exosomal circRNAs for cancer detection. PMID:27308606

  16. 17 CFR 230.253 - Offering circular.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... in boldfaced type at least as large as that used generally in the body of such offering circular: THE... COMPLETENESS OF ANY OFFERING CIRCULAR OR OTHER SELLING LITERATURE. THESE SECURITIES ARE OFFERED PURSUANT TO...

  17. Laser-assisted bremsstrahlung for circular and linear polarization

    SciTech Connect

    Schnez, Stephan; Loetstedt, Erik; Jentschura, Ulrich D.; Keitel, Christoph H.

    2007-05-15

    We numerically evaluate the cross sections for spontaneous bremsstrahlung emission in a laser field for both circular and linear laser polarization, in a regime where the classical ponderomotive energies for the considered laser intensities are considerably larger than the rest mass of the electron. A fully relativistic quantum-electrodynamic approach using the Volkov solutions of an electron in an external field and Dirac-Volkov propagators for the intermediate electrons is applied. We compare circular to linear polarization and point out several interesting features of the laser-dressed cross sections. Regularizations in both electron and photon propagators are required. Specifically, imaginary mass and energy shifts of the electron must be implemented near resonances which correspond to Doppler-shifted harmonics of the laser frequency. We also introduce a screening to the Coulomb potential in order to avoid long-range Coulomb infinities at zero momentum transfer.

  18. Circular on planned parenthood, 1987.

    PubMed

    1987-01-01

    In 1987 fourteen units of the Government of Henan issued a Circular stating that: "Planned parenthood must be publicized deep into the grass roots and among the people, and importance must be attached to results." The Circular stresses: "In the propaganda drive, it is necessary to successfully grasp three key links: 1. It is necessary to disseminate intensively the important directive on population problems that is contained in the report of the 13th CPC National Congress and the seriousness of the population situation of our country and province so that the cadres and the masses can understand the relationship between population control and the achievement of the strategic target of the three big steps, understand the reason for carrying out planned parenthood, understand that the one-child policy is still advocated, and conscientiously carry out planned parenthood. 2. It is essential to succeed in propagating knowledge of contraception, sterilization, childbirth, and child care and in conducting ideological education for those who undergo operations and for their family members. 3. It is imperative to visit those who have undergone operations and to help them solve practically their difficulties in making a living." The Circular concludes by demanding that under the unified leadership of party committees and governments at all levels, the propaganda drive be carried out by relying on the efforts of all of society. In conjunction with their own work, departments, including the propaganda, education, public health, and cultural departments, must carry out propaganda and education for planned parenthood. PMID:12346601

  19. The circular internal hydraulic jump

    NASA Astrophysics Data System (ADS)

    Thorpe, S. A.; Kavcic, I.

    Circular hydraulic jumps are familiar in single layers. Here we report the discovery of similar jumps in two-layer flows. A thin jet of fluid impinging vertically onto a rigid horizontal plane surface submerged in a deep layer of less-dense miscible fluid spreads radially, and a near-circular internal jump forms within a few centimetres from the point of impact with the plane surface. A jump is similarly formed as a jet of relatively less-dense fluid rises to the surface of a deep layer of fluid, but it appears less stable or permanent in form. Several experiments are made to examine the case of a downward jet onto a horizontal plate, the base of a square or circular container. The inlet Reynolds numbers, Re, of the jet range from 112 to 1790. Initially jumps have an undular, laminar form with typically 2-4 stationary waves on the interface between the dense and less-dense layers but, as the depth of the dense layer beyond the jump increases, the transitions become more abrupt and turbulent, resulting in mixing between the two layers. During the transition to a turbulent regime, single and sometimes moving multiple cusps are observed around the periphery of jumps. A semi-empirical model is devised that relates the parameters of the laboratory experiment, i.e. flow rate, inlet nozzle radius, kinematic viscosity and reduced gravity, to the layer depth beyond the jump and the radius at which an undular jump occurs. The experiments imply that surface tension is not an essential ingredient in the formation of circular hydraulic jumps and demonstrate that stationary jumps can exist in stratified shear flows which can be represented as two discrete layers. No stationary circular undular jumps are found, however, in the case of a downward jet of dense fluid when the overlying, less-dense, fluid is stratified, but a stationary turbulent transition is observed. This has implications for the existence of stationary jumps in continuously stratified geophysical flows: results

  20. Some characteristics of the design of heads for the cutting of bevel gears with negative curvature of the circular-arc tooth line

    NASA Astrophysics Data System (ADS)

    Savinov, A. P.; Iastrebov, V. M.

    The principles of the design of the external and internal finishing cutters of heads for the machining of bevel gears with negative curvature of the circular-arc tooth line are examined. The differences between heads for the machining of circular-arc teeth with positive and negative curvatures are discussed. A newly developed design of a head for the machining of bevel gears with negative curvature of the circular-arc tooth is described as an example.

  1. Effects of a Non-Circular Chainring on Sprint Performance During a Cycle Ergometer Test.

    PubMed

    Hintzy, Frédérique; Grappe, Frédéric; Belli, Alain

    2016-06-01

    Non-circular chainrings have been reported to alter the crank angular velocity profile over a pedal revolution so that more time is spent in the effective power phase. The purpose of this study was to determine whether sprint cycling performance could be improved using a non-circular chainring (Osymetric: ellipticity 1.25 and crank lever mounted nearly perpendicular to the major axis), in comparison with a circular chainring. Twenty sprint cyclists performed an 8 s sprint on a cycle ergometer against a 0.5 N/kg(-1) friction force in four crossing conditions (non-circular or circular chainring with or without clipless pedal). Instantaneous force, velocity and power were continuously measured during each sprint. Three main characteristic pedal downstrokes were selected: maximal force (in the beginning of the sprint), maximal power (towards the middle), and maximal velocity (at the end of the sprint). Both average and instantaneous force, velocity and power were calculated during the three selected pedal downstrokes. The important finding of this study was that the maximal power output was significantly higher (+ 4.3%, p < 0.05) when using the non-circular chainring independent from the shoe-pedal linkage condition. This improvement is mainly explained by a significantly higher instantaneous external force that occurs during the downstroke. Non-circular chainring can have potential benefits on sprint cycling performance. Key pointsThe Osymetric non-circular chainring significantly maximized crank power by 4.3% during sprint cycling, in comparison with a circular chainring.This maximal power output improvement was due to significant higher force developed when the crank was in the effective power phase.This maximal power output improvement was independent from the shoe-pedal linkage condition.Present benefits provided by the non-circular chainring on pedalling kinetics occurred only at high cadences. PMID:27274658

  2. Effects of a Non-Circular Chainring on Sprint Performance During a Cycle Ergometer Test

    PubMed Central

    Hintzy, Frédérique; Grappe, Frédéric; Belli, Alain

    2016-01-01

    Non-circular chainrings have been reported to alter the crank angular velocity profile over a pedal revolution so that more time is spent in the effective power phase. The purpose of this study was to determine whether sprint cycling performance could be improved using a non-circular chainring (Osymetric: ellipticity 1.25 and crank lever mounted nearly perpendicular to the major axis), in comparison with a circular chainring. Twenty sprint cyclists performed an 8 s sprint on a cycle ergometer against a 0.5 N/kg-1 friction force in four crossing conditions (non-circular or circular chainring with or without clipless pedal). Instantaneous force, velocity and power were continuously measured during each sprint. Three main characteristic pedal downstrokes were selected: maximal force (in the beginning of the sprint), maximal power (towards the middle), and maximal velocity (at the end of the sprint). Both average and instantaneous force, velocity and power were calculated during the three selected pedal downstrokes. The important finding of this study was that the maximal power output was significantly higher (+ 4.3%, p < 0.05) when using the non-circular chainring independent from the shoe-pedal linkage condition. This improvement is mainly explained by a significantly higher instantaneous external force that occurs during the downstroke. Non-circular chainring can have potential benefits on sprint cycling performance. Key points The Osymetric non-circular chainring significantly maximized crank power by 4.3% during sprint cycling, in comparison with a circular chainring. This maximal power output improvement was due to significant higher force developed when the crank was in the effective power phase. This maximal power output improvement was independent from the shoe-pedal linkage condition. Present benefits provided by the non-circular chainring on pedalling kinetics occurred only at high cadences. PMID:27274658

  3. Circular orbits and related quasiharmonic oscillatory motion of charged particles around weakly magnetized rotating black holes

    NASA Astrophysics Data System (ADS)

    Tursunov, Arman; Stuchlík, Zdeněk; Kološ, Martin

    2016-04-01

    We study the motion of charged particles in the field of a rotating black hole immersed into an external asymptotically uniform magnetic field, focusing on the epicyclic quasicircular orbits near the equatorial plane. Separating the circular orbits into four qualitatively different classes according to the sign of the canonical angular momentum of the motion and the orientation of the Lorentz force, we analyze the circular orbits using the so-called force formalism. We find the analytical solutions for the radial profiles of velocity, specific angular momentum, and specific energy of the circular orbits in dependence on the black-hole dimensionless spin and the magnetic field strength. The innermost stable circular orbits are determined for all four classes of the circular orbits. The stable circular orbits with an outward-oriented Lorentz force can extend to radii lower than the radius of the corresponding photon circular geodesic. We calculate the frequencies of the harmonic oscillatory motion of the charged particles in the radial and vertical directions related to the equatorial circular orbits and study the radial profiles of the radial, ωr; vertical, ωθ; and orbital, ωϕ, frequencies, finding significant differences in comparison to the epicyclic geodesic circular motion. The most important new phenomenon is the existence of toroidal charged particle epicyclic motion with ωr˜ωθ≫ωϕ that could occur around retrograde circular orbits with an outward-oriented Lorentz force. We demonstrate that for the rapidly rotating black holes the role of the "Wald induced charge" can be relevant.

  4. Magnetoresistance of single Permalloy circular rings

    NASA Astrophysics Data System (ADS)

    Vavassori, P.; Busato, A.; Chiapatti, A.; di Bona, A.; Valeri, S.; Metlushko, V.; Ilic, B.

    2007-09-01

    We have measured magnetoresistance in single, 1 μm external diameter, Permalloy (Ni 80Fe 20) circular rings with varied inner hole diameter of 150, 300, and 600 nm and film thickness of 25 nm. The Permalloy ring structures and the 10-nm-thick, 250-nm-wide Au nanocontacts were fabricated on a SiO 2/Si substrate using e-beam lithography. Using a four contact geometry we studied the dependence of the magnetoresistance on the direction of the applied field. The experimental data are explained by considering only the conventional anisotropic magnetoresistance effect. Numerical simulations of the current distribution within the samples combined with micromagnetic simulations of the field dependent magnetization profile, yield good agreement with the experimental data. Upon increasing the inner hole diameter (viz. decreasing the ring width) the magnetoresistance measurements show a transition of the reversal process from the "vortex nucleation-displacement-annihilation" sequence to the "onion state-reversed onion state" sequence, typical of narrow nanorings.

  5. Diabatic flow boiling in circular transparent microchannels

    NASA Astrophysics Data System (ADS)

    Silvério, V.; Moreira, A. L. N.

    2012-11-01

    The horizontally assembled circular microchannel (Dh= 543μm, LHT = 60mm) made of transparent borosilicate glass is kept under constant wall heat flux conditions by means of a transparent metallic thin film deposit at the channel external wall as in Silvério and Moreira [1]. Heat transfer and pressure drop measurements are achieved by measuring the temperature and pressure at the channel inlet and outlet. Temperature is also measured along the channel outer wall. Experiments are carried with two different fluids, ethanol and methanol. Inlet liquid subcooling is of 297K, mass fluxes, G, up to 689kg.m-2.s-1 and imposed heat fluxes, q"s, up to 12.5W.cm-2 at ΔTsub from 0.8 to 50K. Synchronized high-speed visualization and microscope optics are used to determine dominant two-phase flow patterns and characterize hydrodynamic instabilities. Vapor qualities, χ, of -0.1 (indicating a subcooled liquid state) to 0.5 are under investigation. Semi-periodic variation of the flow patterns is noticeable for different flow conditions.

  6. Exon circularization requires canonical splice signals.

    PubMed

    Starke, Stefan; Jost, Isabelle; Rossbach, Oliver; Schneider, Tim; Schreiner, Silke; Hung, Lee-Hsueh; Bindereif, Albrecht

    2015-01-01

    Circular RNAs (circRNAs), an abundant class of noncoding RNAs in higher eukaryotes, are generated from pre-mRNAs by circularization of adjacent exons. Using a set of 15 circRNAs, we demonstrated their cell-type-specific expression and circular versus linear processing in mammalian cells. Northern blot analysis combined with RNase H cleavage conclusively proved a circular configuration for two examples, LPAR1 and HIPK3. To address the circularization mechanism, we analyzed the sequence requirements using minigenes derived from natural circRNAs. Both canonical splice sites are required for circularization, although they vary in flexibility and potential use of cryptic sites. Surprisingly, we found that no specific circRNA exon sequence is necessary and that potential flanking intron structures can modulate circularization efficiency. In combination with splice inhibitor assays, our results argue that the canonical spliceosomal machinery functions in circRNA biogenesis, constituting an alternative splicing mode. PMID:25543144

  7. Automated External Defibrillator

    MedlinePlus

    ... from the NHLBI on Twitter. What Is an Automated External Defibrillator? An automated external defibrillator (AED) is a portable device that ... Institutes of Health Department of Health and Human Services USA.gov

  8. Hexapod External Fixation of Tibia Fractures in Children.

    PubMed

    Iobst, Christopher A

    2016-06-01

    Most tibia fractures in children can be treated nonoperatively. For fractures that do require surgery, however, the most common methods of management include plating or flexible nail insertion. Some fracture patterns, such as periphyseal fractures, fractures with bone and/or soft tissue loss, or fractures with delayed presentation, are not easily amenable to these techniques. Hexapod external fixators are especially helpful in these difficult cases. The purpose of this review is to discuss the principles of performing hexapod circular external fixation applied to pediatric tibia fractures. Some of the additional capabilities of the hexapod external fixator will also be highlighted. PMID:27078228

  9. Flexural Vibrations of Circular Beams

    NASA Astrophysics Data System (ADS)

    Silverman, I. K.

    1998-03-01

    For circular cylindrical beams, the Timoshenko theory, which includes shear and rotary effects, can be applied by introducing a constantK‧=0·9. The study presented here takes into account the actual configuration and thus makes it an integral part of the analysis. A variational approach previously used [7] is followed. A simplification of the three-dimensional problem is obtained using the inverse method due to St. Venant. A biquadratic equation yields numerical results for the natural frequencies of the first three modes for the following cases: simply supported, fixed-fixed, free-free and fixed-free.

  10. Spontaneous circular polarization of photoluminescence from WS2 single layers

    NASA Astrophysics Data System (ADS)

    Scrace, Thomas; Tsai, Yutsung; Barman, Biplob; Zhang, Peiyao; Petrou, Athos; Kioseoglou, George; Korkusinski, Marek; Ozfidan, Isil; Hawrylak, Pawel

    2015-03-01

    We have carried out a magnetoluminescence study of WS2 single layer crystals excited with linearly polarized light. The photoluminescence (PL) contains two features. The first is associated with the neutral exciton (X0) ; the second feature is due to the recombination of negatively charged excitons (X-) in the presence of a two-dimensional electron gas (2DEG). The X- - 2 DEG feature has a non-zero circular polarization up to 19% at zero magnetic field even though the PL excitation light is linearly polarized. The circular polarization is effected by an external magnetic field applied perpendicular to the crystal plane at 2 % / Tesla . The zero field circular polarization of the X- - 2 DEG photoluminescence feature is interpreted as due to the existence of a spontaneously valley polarized 2DEG. This is a new state possible in WS2 due to valley and spin locking and a strong electron-electron interaction. Work at SUNY Buffalo has been supported by ONR. I.O., M.K. and P.H. acknowledge support of NRC QPSS program and of NSERC.

  11. Time Circular Birefringence in Time-Dependent Magnetoelectric Media

    PubMed Central

    Zhang, Ruo-Yang; Zhai, Yan-Wang; Lin, Shi-Rong; Zhao, Qing; Wen, Weijia; Ge, Mo-Lin

    2015-01-01

    Light traveling in time-dependent media has many extraordinary properties which can be utilized to convert frequency, achieve temporal cloaking, and simulate cosmological phenomena. In this paper, we focus on time-dependent axion-type magnetoelectric (ME) media, and prove that light in these media always has two degenerate modes with opposite circular polarizations corresponding to one wave vector , and name this effect “time circular birefringence” (TCB). By interchanging the status of space and time, the pair of TCB modes can appear simultaneously via “time refraction” and “time reflection” of a linear polarized incident wave at a time interface of ME media. The superposition of the two TCB modes causes the “time Faraday effect”, namely the globally unified polarization axes rotate with time. A circularly polarized Gaussian pulse traversing a time interface is also studied. If the wave-vector spectrum of a pulse mainly concentrates in the non-traveling-wave band, the pulse will be trapped with nearly fixed center while its intensity will grow rapidly. In addition, we propose an experimental scheme of using molecular fluid with external time-varying electric and magnetic fields both parallel to the direction of light to realize these phenomena in practice. PMID:26329928

  12. Flow-induced vibration of circular cylindrical structures

    SciTech Connect

    Chen, S.S.

    1987-01-01

    This book presents the flow-induced vibration of circular cylinders in quiescent fluid, axial flow, and crossflow, and applications of the analytical methods and experimental data in design evaluation of various system components consisting of circular cylinders. The information is organized into five general topical areas: Introduction: Chapter 1 presents an overview of flow-induced vibration of circular cylinders. It includes examples of flow-induced vibration, various fluid force components, and nondimensional parameters as well as different excitation mechanisms. The general principles are applicable under different flow conditions. Quiescent Fluid: Fluid inertia and fluid damping are discussed in Chapters 2, 3 and 4. Various flow theories are applied in different situations. Axial Flow: Axial flow can cause subcritical vibration and instability. Chapter 5 summarizes the results for internal flow, while Chapter 6 considers external flow. Both theoretical results and experimental data are examined. Crossflow: Different excitation mechanisms can be dominant in different conditions for crossflow. Those include turbulent buffeting, acoustic resonance, vortex excitation, and dynamic instability. Design Considerations: Applications of the general methods of analysis in the design evaluation of system components are described and various techniques to avoid detrimental vibration are presented.

  13. Time Circular Birefringence in Time-Dependent Magnetoelectric Media.

    PubMed

    Zhang, Ruo-Yang; Zhai, Yan-Wang; Lin, Shi-Rong; Zhao, Qing; Wen, Weijia; Ge, Mo-Lin

    2015-01-01

    Light traveling in time-dependent media has many extraordinary properties which can be utilized to convert frequency, achieve temporal cloaking, and simulate cosmological phenomena. In this paper, we focus on time-dependent axion-type magnetoelectric (ME) media, and prove that light in these media always has two degenerate modes with opposite circular polarizations corresponding to one wave vector , and name this effect "time circular birefringence" (TCB). By interchanging the status of space and time, the pair of TCB modes can appear simultaneously via "time refraction" and "time reflection" of a linear polarized incident wave at a time interface of ME media. The superposition of the two TCB modes causes the "time Faraday effect", namely the globally unified polarization axes rotate with time. A circularly polarized Gaussian pulse traversing a time interface is also studied. If the wave-vector spectrum of a pulse mainly concentrates in the non-traveling-wave band, the pulse will be trapped with nearly fixed center while its intensity will grow rapidly. In addition, we propose an experimental scheme of using molecular fluid with external time-varying electric and magnetic fields both parallel to the direction of light to realize these phenomena in practice. PMID:26329928

  14. Radial Internal Material Handling System (RIMS) for Circular Habitat Volumes

    NASA Technical Reports Server (NTRS)

    Howe, A. Scott; Haselschwardt, Sally

    2012-01-01

    A Radial Internal Material Handling System (RIMS) has been developed to service a circular floor area in variable gravity. On planetary surfaces, pressurized human habitable volumes will require a means to carry heavy equipment between various locations within the volume of the habitat, regardless of the partial gravity (Earth, moon, Mars, etc). On the NASA Habitat Demonstration Unit (HDU), a vertical cylindrical volume, it was determined that a variety of heavy items would need to be carried back and forth from deployed locations to the General Maintenance Work Station (GMWS) when in need of repair, and other equipment may need to be carried inside for repairs, such as rover parts and other external equipment. The vertical cylindrical volume of the HDU lent itself to a circular overhead track and hoist system that allows lifting of heavy objects from anywhere in the habitat to any other point in the habitat interior. In addition, the system is able to hand off lifted items to other material handling systems through the side hatches, such as through an airlock. This paper describes the RIMS system which is scalable for application in a variety of circular habitat volumes.

  15. Method of oriented circular dichroism.

    PubMed Central

    Wu, Y; Huang, H W; Olah, G A

    1990-01-01

    We present a new method for determining the orientation of alpha-helical sections of proteins or peptides in membrane. To apply this method, membranes containing proteins must be prepared in a multilayer array. Circular dichroism (CD) spectra of the multilayer sample are then measured at the normal as well as oblique incident angles with respect to the bilayer planes; we call such spectra oriented circular dichroism (OCD). The procedure of OCD measurement, particularly the ways to avoid the spectral artifacts due to the effects of dielectric interfaces, linear dichroism and birefringence, and the method of data analysis are described in detail. To illustrate the method, we analyze the OCD of alamethicin in diphytanoylphosphatidylcholine multilayers. We conclude unambiguously that the helical section of alamethicin is parallel to the membrane normal when the sample is in the full-hydration state, but the helical section rotates to the plane of membrane when the sample is in a low-hydration state. We also obtained the parallel and perpendicular CD spectra of alpha-helix, and found them to be in agreement with previous theoretical calculations based on the exciton theory. These spectra are useful for analyzing protein orientations in future experiments. Images FIGURE 5 PMID:2344464

  16. Physics at Future Circular Colliders

    NASA Astrophysics Data System (ADS)

    Kotwal, Ashutosh

    2016-03-01

    The Large Hadron Collider has been a grand success with the discovery of the Higgs boson, with bright prospects for additional discoveries since the recent increase in collider energy and the anticipated large datasets. Big open questions such as the nature of dark matter, the origin of the matter-antimatter asymmetry in the Universe, and the theoretical puzzle of the finely-tuned parameters in the Higgs sector, demand new physics principles that extend the established Standard Model paradigm. Future circular colliders in a substantially larger tunnel can house both a high luminosity electron-positron collider for precision measurements of Higgs and electroweak parameters, as well as a very high energy proton-proton collider which can directly manifest particles associated with these new physics principles. We discuss the physics goals of these future circular colliders, and the prospects for elucidating fundamental new laws of nature that will significantly extend our understanding of the Universe. Detailed studies of the discovery potential in specific benchmark models will be presented, with implications for detector design.

  17. External artery heat pipe

    NASA Technical Reports Server (NTRS)

    Gernert, Nelson J. (Inventor); Ernst, Donald M. (Inventor); Shaubach, Robert M. (Inventor)

    1989-01-01

    An improved heat pipe with an external artery. The longitudinal slot in the heat pipe wall which interconnects the heat pipe vapor space with the external artery is completely filled with sintered wick material and the wall of the external artery is also covered with sintered wick material. This added wick structure assures that the external artery will continue to feed liquid to the heat pipe evaporator even if a vapor bubble forms within and would otherwise block the liquid transport function of the external artery.

  18. Circular permutant GFP insertion folding reporters

    SciTech Connect

    Waldo, Geoffrey S.; Cabantous, Stephanie

    2013-04-16

    Provided are methods of assaying and improving protein folding using circular permutants of fluorescent proteins, including circular permutants of GFP variants and combinations thereof. The invention further provides various nucleic acid molecules and vectors incorporating such nucleic acid molecules, comprising polynucleotides encoding fluorescent protein circular permutants derived from superfolder GFP, which polynucleotides include an internal cloning site into which a heterologous polynucleotide may be inserted in-frame with the circular permutant coding sequence, and which when expressed are capable of reporting on the degree to which a polypeptide encoded by such an inserted heterologous polynucleotide is correctly folded by correlation with the degree of fluorescence exhibited.

  19. Circular permutant GFP insertion folding reporters

    DOEpatents

    Waldo, Geoffrey S.; Cabantous, Stephanie

    2008-06-24

    Provided are methods of assaying and improving protein folding using circular permutants of fluorescent proteins, including circular permutants of GFP variants and combinations thereof. The invention further provides various nucleic acid molecules and vectors incorporating such nucleic acid molecules, comprising polynucleotides encoding fluorescent protein circular permutants derived from superfolder GFP, which polynucleotides include an internal cloning site into which a heterologous polynucleotide may be inserted in-frame with the circular permutant coding sequence, and which when expressed are capable of reporting on the degree to which a polypeptide encoded by such an inserted heterologous polynucleotide is correctly folded by correlation with the degree of fluorescence exhibited.

  20. Circular permutant GFP insertion folding reporters

    DOEpatents

    Waldo, Geoffrey S.; Cabantous, Stephanie

    2011-06-14

    Provided are methods of assaying and improving protein folding using circular permutants of fluorescent proteins, including circular permutants of GFP variants and combinations thereof. The invention further provides various nucleic acid molecules and vectors incorporating such nucleic acid molecules, comprising polynucleotides encoding fluorescent protein circular permutants derived from superfolder GFP, which polynucleotides include an internal cloning site into which a heterologous polynucleotide may be inserted in-frame with the circular permutant coding sequence, and which when expressed are capable of reporting on the degree to which a polypeptide encoded by such an inserted heterologous polynucleotide is correctly folded by correlation with the degree of fluorescence exhibited.

  1. Circular permutant GFP insertion folding reporters

    DOEpatents

    Waldo, Geoffrey S; Cabantous, Stephanie

    2013-02-12

    Provided are methods of assaying and improving protein folding using circular permutants of fluorescent proteins, including circular permutants of GFP variants and combinations thereof. The invention further provides various nucleic acid molecules and vectors incorporating such nucleic acid molecules, comprising polynucleotides encoding fluorescent protein circular permutants derived from superfolder GFP, which polynucleotides include an internal cloning site into which a heterologous polynucleotide may be inserted in-frame with the circular permutant coding sequence, and which when expressed are capable of reporting on the degree to which a polypeptide encoded by such an inserted heterologous polynucleotide is correctly folded by correlation with the degree of fluorescence exhibited.

  2. Bicondylar tibial fractures: Internal or external fixation?

    PubMed

    Kumar, Gunasekaran; Peterson, Nicholas; Narayan, Badri

    2011-03-01

    Bicondylar fractures of the tibia, representing the Schatzker V and VI fractures represent a challenging problem. Any treatment protocol should aim at restoring articular congruity and the metaphyseo-diaphsyeal dissociation (MDD)-both of these are equally important to long-term outcome. Both internal and external fixations have their proponents, and each method of treatment is associated with its unique features and complications. We review the initial and definitive management of these injuries, and the advantages and disadvantages of each method of definitive fixation. We suggest the use of a protocol for definitive management, using either internal or external fixation as deemed appropriate. This protocol is based on the fracture configuration, local soft tissue status and patient condition. In a nutshell, if the fracture pattern and soft tissue status are amenable plate fixation (single or double) is performed, otherwise limited open reduction and articular surface reconstruction with screws and circular frame is performed. PMID:21430865

  3. Electrodynamics of circular dichroism and its application in the construction of a circular polaroid

    NASA Astrophysics Data System (ADS)

    Volobuev, A. N.

    2016-03-01

    Electrodynamic principles of circular dichroism are developed using a concept of conducting circular structures in matter. A simplified representation of material equations for an optically active medium is obtained in the absence of a transition to the complex domain. A dependence of the absorption coefficient of a circular polarization as a component of the linearly polarized radiation on material parameters is found. Such parameters are analyzed to reveal a possibility of construction of a circular polaroid.

  4. Individual muscle contributions to circular turning mechanics.

    PubMed

    Ventura, Jessica D; Klute, Glenn K; Neptune, Richard R

    2015-04-13

    Turning is an activity of daily living that involves both the acceleration of the body center-of-mass (COM) towards the center of curvature and rotation of the pelvis towards the new heading. The purpose of this study was to understand which muscles contribute to turning using experimentation, musculoskeletal modeling and simulation. Ten healthy adults consented to walk around a 1-m radius circular path at their self-selected walking speed and then along a straight line at the same speed. Forward dynamics simulations of the individual subjects during the turning and straight-line walking tasks were generated to identify the contributions of individual muscle groups to the body mediolateral and anterior-posterior COM acceleration impulse and to the pelvis angular acceleration impulse. The stance leg gluteus medius and ankle plantarflexor muscles and the swing leg adductor muscles were the primary contributors to redirect the body's COM relative to straight-line walking. In some cases, contributions to mediolateral COM acceleration were modulated through changes in leg orientation rather than through changes in muscle force. While modulation of the muscle contributions generally occurred in both the inner and outer legs, greater changes were observed during inner single-leg support than during outer single-leg support. Total pelvis angular acceleration was minimal during the single-support phase, but the swing leg muscles contributed significantly to balancing the internal and external rotation of the pelvis. The understanding of which muscles contribute to turning the body during walking may help guide the development of more effective locomotor therapies for those with movement impairments. PMID:25700608

  5. Instability waves in supersonic jets confined in non-circular ducts

    NASA Astrophysics Data System (ADS)

    Viswanathan, Krishnamurthy; Morris, Philip J.; Chen, G.

    1992-01-01

    The instability of supersonic jets confined in circular and non-circular ducts is investigated both analytically and numerically. A technique based on the boundary element method is developed to study jets confined in ducts of non-circular geometry. It is shown that the presence of an outer wall introduces additional instability modes for the circular outer duct case. A highly supersonic unconfined jet possesses many modes of instability. These include the Kelvin-Helmholtz instability and supersonic instabilities. The modifications of these instabilities by a coflowing stream and an outer wall are examined. It is shown that the presence of an outer wall alters the instability modes of the jet. For the case of a circular jet in a circular duct, both the vortex sheet model and a model that includes the effect of finite shear layer thickness are considered. The results of these calculations are compared with those for unconfined supersonic jets with external flow. Finally, the effects of changes in the duct geometry on the instability modes are examined.

  6. External radiation surveillance

    SciTech Connect

    Antonio, E.J.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site.

  7. A Random Walk on a Circular Path

    ERIC Educational Resources Information Center

    Ching, W.-K.; Lee, M. S.

    2005-01-01

    This short note introduces an interesting random walk on a circular path with cards of numbers. By using high school probability theory, it is proved that under some assumptions on the number of cards, the probability that a walker will return to a fixed position will tend to one as the length of the circular path tends to infinity.

  8. Microstrip Antenna Generates Circularly Polarized Beam

    NASA Technical Reports Server (NTRS)

    Huang, J.

    1986-01-01

    Circular microstrip antenna excited with higher order transverse magnetic (TM) modes generates circularly polarized, conical radiation patterns. Found both theoretically and experimentally that peak direction of radiation pattern is varied within wide angular range by combination of mode selection and loading substrate with materials of different dielectric constants.

  9. Circular RNAs: diversity of form and function.

    PubMed

    Lasda, Erika; Parker, Roy

    2014-12-01

    It is now clear that there is a diversity of circular RNAs in biological systems. Circular RNAs can be produced by the direct ligation of 5' and 3' ends of linear RNAs, as intermediates in RNA processing reactions, or by "backsplicing," wherein a downstream 5' splice site (splice donor) is joined to an upstream 3' splice site (splice acceptor). Circular RNAs have unique properties including the potential for rolling circle amplification of RNA, the ability to rearrange the order of genomic information, protection from exonucleases, and constraints on RNA folding. Circular RNAs can function as templates for viroid and viral replication, as intermediates in RNA processing reactions, as regulators of transcription in cis, as snoRNAs, and as miRNA sponges. Herein, we review the breadth of circular RNAs, their biogenesis and metabolism, and their known and anticipated functions. PMID:25404635

  10. Gauge-Invariant Formulation of Circular Dichroism.

    PubMed

    Raimbault, Nathaniel; de Boeij, Paul L; Romaniello, Pina; Berger, J A

    2016-07-12

    Standard formulations of magnetic response properties, such as circular dichroism spectra, are plagued by gauge dependencies, which can lead to unphysical results. In this work, we present a general gauge-invariant and numerically efficient approach for the calculation of circular dichroism spectra from the current density. First we show that in this formulation the optical rotation tensor, the response function from which circular dichroism spectra can be obtained, is independent of the origin of the coordinate system. We then demonstrate that its trace is independent of the gauge origin of the vector potential. We also show how gauge invariance can be retained in practical calculations with finite basis sets. As an example, we explain how our method can be applied to time-dependent current-density-functional theory. Finally, we report gauge-invariant circular dichroism spectra obtained using the adiabatic local-density approximation. The circular dichroism spectra we thus obtain are in good agreement with experiment. PMID:27295541

  11. The External Degree Project.

    ERIC Educational Resources Information Center

    Syracuse Univ., NY. School of Management.

    An external degree is one granted on the basis of academic work undertaken through independent and flexible study and pursued in whole or in part outside of the framework of existing college and university courses. A person's qualifications for an external degree are measured not by a list of accumulated formal courses taken and passed, but by an…

  12. Circular protecting female students, 1988.

    PubMed

    1988-01-01

    In 1988 the Ministry of Education of Benin issued a Circular designed to protect female students from sexual advances from male students and teachers. Teachers who are suspected of having sexual relations with a student are to receive a note in their file or can be suspended for a month. Teachers who have raped a student or are responsible for a student's pregnancy are to be suspended for three months if the student was not in their class, and six months if she was. Teachers who have incited their sexual partner to have an abortion are subject to demotion. Teachers who are repeat offenders or whose actions have led to an abortion resulting in death are to be fired. Students who have made a female student pregnant are to be suspended from school until delivery of the child and then are to be enrolled in a different school. The directors of schools are asked to put an end to the provocative clothes, make-up, and hairstyles of female students. PMID:12289212

  13. Circular RNAs in Eukaryotic Cells

    PubMed Central

    Chen, Liang; Huang, Chuan; Wang, Xiaolin; Shan, Ge

    2015-01-01

    Circular RNAs (circRNAs) are now recognized as large species of transcripts in eukaryotic cells. From model organisms such as C. elegans, Drosophila, mice to human beings, thousands of circRNAs formed from back-splicing of exons have been identified. The known complexity of transcriptome has been greatly expanded upon the discovery of these RNAs. Studies about the biogenesis and physiological functions have yielded substantial knowledge for the circRNAs, and they are now more likely to be viewed as regulatory elements coded by the genome rather than unavoidable noise of gene expression. Certain human diseases may also relate to circRNAs. These circRNAs show diversifications in features such as sequence composition and cellular localization, and thus we propose that they may be divided into subtypes such as cytoplasmic circRNAs, nuclear circRNAs, and exon-intron circRNAs (EIciRNAs). Here we summarize and discuss knowns and unknowns for these RNAs, and we need to keep in mind that the whole field is still at the beginning of exciting explorations. PMID:27047251

  14. Circular on family planning, 1988.

    PubMed

    1988-01-01

    This Hubei, China, Circular, issued near the end of 1988, provides the following: "The population growth situation in our country is grim. Since 1986, the natural population growth rate has risen continuously. To draw the prompt attention of the whole party and the entire people to the issue of our population, all localities must seriously unfold the activities of publicizing family planning (FP) this winter and next spring, in coordination with education in current affairs. It is necessary to publicize FP in an all-around way and with accuracy, and the activities of publicizing must be carried out effectively in a solid and deep-going way. In the rural areas, stress must be placed on areas where FP work is not carried out well and where there is a prevailing tendency toward early marriage, early child-bearing, and extra-budgetary births. In cities, publicity and education must be conducted especially among the transient population, individual households, and jobless households. During the period of publicity, large-scale street-corner publicity activities must be carried out in cities and towns so as to create strong public opinion and to combine the endeavor to publicize current affairs and policies with the effort to popularize knowledge about contraception and birth-control, to execute measures of contraception and birth control, and to establish FP associations in the countryside." PMID:12289626

  15. Magnetic circular dichroism of non-local surface lattice resonances in magnetic nanoparticle arrays.

    PubMed

    Kataja, Mikko; Pourjamal, Sara; van Dijken, Sebastiaan

    2016-02-22

    Subwavelength metallic particles support plasmon resonances that allow extreme confinement of light down to the nanoscale. Irradiation with left- and right hand circularly polarized light results in the excitation of circular plasmon modes with opposite helicity. The Lorenz force lifts the degeneracy of the two modes in magnetic nanoparticles. Consequently, the confinement and frequency of localized surface plasmon resonances can be tuned by an external magnetic field. In this paper, we experimentally demonstrate this effect for nickel nanoparticles using magnetic circular dichroism (MCD). Besides, we show that non-local surface lattice resonances in periodic arrays of the same nanoparticles significantly enhance the MCD signal. A numerical model based on the modified long wavelength approximation is used to reproduce the main features in the experimental spectra and provide design rules for large MCD effects in sensing applications. PMID:26907013

  16. Entanglement of quantum circular states of light

    NASA Astrophysics Data System (ADS)

    Horoshko, D. B.; De Bièvre, S.; Kolobov, M. I.; Patera, G.

    2016-06-01

    We present a general approach to calculating the entanglement of formation for superpositions of two-mode coherent states, placed equidistantly on a circle in phase space. We show that in the particular case of rotationally invariant circular states the Schmidt decomposition of two modes, and therefore the value of their entanglement, are given by analytical expressions. We analyze the dependence of the entanglement on the radius of the circle and number of components in the superposition. We also show that the set of rotationally invariant circular states creates an orthonormal basis in the state space of the harmonic oscillator, and this basis is advantageous for representation of other circular states of light.

  17. Circular Polarization in PKS 1519-273

    NASA Astrophysics Data System (ADS)

    Bennett, W.; Macquart, J. P.; Johnston, H.; Jauncey, D.

    2005-12-01

    The intra-day variable BL Lac PKS 1519-273 exhibits variations at centimeter wavelengths in total intensity, linear polarization, and circular polarization. Their variability is caused by scintillation due to the interstellar medium. PKS 1519-273 displays 4% circular polarization at 4.8 GHz and the variability has persisted as long as the source has been observed. We present observations of this source over several years, showing that the circularly polarized emission is highly variable on micro-arcsecond scales. We determine properties of the structure of the emission by examining the light curves and associated scintillation theory.

  18. Generation of circular polarization of the CMB

    NASA Astrophysics Data System (ADS)

    Zarei, M.; Bavarsad, E.; Haghighat, M.; Mohammadi, R.; Motie, I.; Rezaei, Z.

    2010-04-01

    According to the standard cosmology, near the last scattering surface, the photons scattered via Compton scattering are just linearly polarized and then the primordial circular polarization of the cosmic microwave background (CMB) photons is zero. In this work we show that CMB polarization acquires a small degree of circular polarization when a background magnetic field is considered or the quantum electrodynamic sector of standard model is extended by Lorentz-noninvariant operators as well as noncommutativity. The existence of circular polarization for the CMB radiation may be verified during future observation programs, and it represents a possible new channel for investigating new physics effects.

  19. The circular polarization interferometer based surface plasmon biosensor

    NASA Astrophysics Data System (ADS)

    Jan, C.-M.; Lee, Y.-H.; Lee, C.-K.

    2010-02-01

    Circular polarization interferometry configuration was used to develop surface plasmon based instrument, which had two light beams with p- and s- polarization states individually within the common path. We used evanescent field to determine the concentration of the biological sample via varying incident angles enabled phase interrogation. The instrument named "OBMorph" includes a light source, an easy to use incident angle varying scheme based on a parabolic and a spherical mirrors, and prism coupled sample stages. To increase the metrology sensitivity, which depends on precisely control the angular resolution, a precision step-motor coupled with a parabolic mirror were used to control the incident angle accurately. By using fault tolerance algorithm, the imperfect adjustment of circular polarization interferometer was eliminated to obtain a perfect Lissajous curve needed for circular polarization interferometry. The instrument developed was shown to have resolution as high as 4.92×10-6 RIU. The effect that refractive index of ITO thin film changes with respect to externally applied voltage was also adopted by coating an ITO thin film onto biochips so as to shift the surface plasmon resonance angle for larger phase interrogation ranges. We successfully measured CRP and anti-CRP specific interaction in 0.75 μg/ml ~ 400 μg/ml ranges. In addition, the concentrations of tuberculosis inhibitor - DHFR and compound Mg2P4O7 that can interact with CYP450 were also quantified successfully. The OBMorph was shown to have potential applications in areas such as flat panel displays, optical coating, and drug delivery, to name a few.

  20. Future of External Reporting

    ERIC Educational Resources Information Center

    Powers, Kristina

    2015-01-01

    This chapter builds on prior chapters and focuses on higher education trends on the horizon and the resulting impact on external reporting for institutional researchers. Three practical recommendations and examples for institutional researchers are also presented.

  1. Evaluating External Communication.

    ERIC Educational Resources Information Center

    DeSantis, James R.

    1978-01-01

    Effective external communication by higher education institutions is described as an ongoing program, based on objective research, continuous informal feedback, and informed anticipation of changes in the environment that will force changes in the institution. (JMF)

  2. Dual frequency launcher for circularly polarized antenna

    NASA Astrophysics Data System (ADS)

    Chen, Ming H.

    1989-10-01

    A dual frequency antenna feed is formed from a central, circular waveguide connected to the flat boundry of circular, disk-shaped resonant cavity. A second circular waveguide is connected one end of a disk-shaped resonant cavity. Energy of one frequency enters and exits the cavity along the common axis of the waveguides. Energy of the second frequency is introduced to the same resonant cavity by way of a plurality of bandpass filters, also connected to the cavity. This energy enters by way of slots in the cylindrical walls of the cavity. The central circular waveguide is propagating at one frequency but cut off at the second frequency. These bandpass filters are at this pass band for the second frequency, but at the rejection band for the first frequency. Therefore, the isolation between these two input ports are obtained.

  3. Low energy aspects of circular accelerators

    SciTech Connect

    Holmes, S.D.

    1990-12-01

    Performance in circular accelerators can be limited by some of the same sorts of phenomena described by Miller and Wangler in their lectures on low energy behavior in linear accelerators. In general the strength of the perturbation required to degrade performance is reduced in circular accelerators due to the repetitive nature of the orbits. For example, we shall see that space-charge can severely limit performance in circular accelerators even when operating far from the space-charge dominated regime'' as defined in linear accelerators. We will be discussing two particular aspects of low energy operation in circular accelerators -- space-charge and transition. Low energy'' is defined within the context of these phenomena. We shall see that the phenomena are really only relevant in hadron accelerators.

  4. Master external pressure charts

    SciTech Connect

    Michalopoulos, E.

    1996-12-01

    This paper presents a method to develop master external pressure charts from which individual external pressure charts for each material specification may be derived. The master external charts can represent a grouping of materials with similar chemical composition, similar stress-strain curves but produced to different strength levels. External pressure charts are used by various Sections of the ASME Boiler and Pressure Vessel and Piping Codes to design various components such as cylinders, sphered, formed heads, tubes, piping, rings and other components, subjected to external pressure or axial compression loads. These charts are pseudo stress-strain curves for groups of materials with similar stress-strain shapes. The traditional approach was originally developed in the 1940`s and is a graphical approach where slopes to the strain curves are drawn graphically from which pseudo-strain levels are calculated. The new method presented in this paper develops mathematical relationships for the material stress-strain curves and the external pressure charts. The method has the ability to calculate stress-strain curves from existing external pressure charts. The relationships are a function of temperature, the modulus of elasticity, yield strength, and two empirical material constants. In this approach, conservative assumptions used to assign materials to lower bound external pressure charts can be removed. This increases the buckling strength capability of many materials in the Code, providing economic benefits while maintaining the margin of safety specified by the Code criteria. The method can also reduce the number of material charts needed in the Code and provides for the capability to extend the existing pressure charts to higher design temperatures. The new method is shown to contain a number of improvements over the traditional approach and is presently under consideration by appropriate ASME Code committees.

  5. Circular DNA Molecules in the Genus Drosophila

    PubMed Central

    Travaglini, E. C.; Schultz, J.

    1972-01-01

    The satellite DNA's from the embryos of five species of Drosophila (D. melanogaster, D. simulans, D. nasuta, D. virilis and D. hydei) have been analyzed for the presence of closed circular duplex DNA molecules, as determined by CsCl-EBr gradients. Circular DNA molecules were found in every species but D. melanogaster. Analyses of cell fractions from adult Drosophila and organ fractions from Drosophila larvae show that fractions containing mitochondria are highly enriched in these molecules. PMID:4643820

  6. CIRCULAR RIBBON FLARES AND HOMOLOGOUS JETS

    SciTech Connect

    Wang Haimin; Liu Chang

    2012-12-01

    Solar flare emissions in the chromosphere often appear as elongated ribbons on both sides of the magnetic polarity inversion line (PIL), which has been regarded as evidence of a typical configuration of magnetic reconnection. However, flares having a circular ribbon have rarely been reported, although it is expected in the fan-spine magnetic topology involving reconnection at a three-dimensional (3D) coronal null point. We present five circular ribbon flares with associated surges, using high-resolution and high-cadence H{alpha} blue wing observations obtained from the recently digitized films of Big Bear Solar Observatory. In all the events, a central parasitic magnetic field is encompassed by the opposite polarity, forming a circular PIL traced by filament material. Consequently, a flare kernel at the center is surrounded by a circular flare ribbon. The four homologous jet-related flares on 1991 March 17 and 18 are of particular interest, as (1) the circular ribbons brighten sequentially, with cospatial surges, rather than simultaneously, (2) the central flare kernels show an intriguing 'round-trip' motion and become elongated, and (3) remote brightenings occur at a region with the same magnetic polarity as the central parasitic field and are co-temporal with a separate phase of flare emissions. In another flare on 1991 February 25, the circular flare emission and surge activity occur successively, and the event could be associated with magnetic flux cancellation across the circular PIL. We discuss the implications of these observations combining circular flare ribbons, homologous jets, and remote brightenings for understanding the dynamics of 3D magnetic restructuring.

  7. Single particle dynamics in circular accelerators

    SciTech Connect

    Ruth, R.D.

    1986-10-01

    The purpose of this paper is to introduce the reader to the theory associated with the transverse dynamics of single particle, in circular accelerators. The discussion begins with a review of Hamiltonian dynamics and canonical transformations. The case of a single particle in a circular accelerator is considered with a discussion of non-linear terms and chromaticity. The canonical perturbation theory is presented and nonlinear resonances are considered. Finally, the concept of renormalization and residue criterion are examined. (FI)

  8. Circular polarization of sunlight reflected by clouds.

    NASA Technical Reports Server (NTRS)

    Hansen, J. E.

    1971-01-01

    Measurements of circular polarization of visible light from planets have recently been reported. It is pointed out that the values measured for the circular polarization for Jupiter and Venus are of the magnitude expected for sunlight reflected by a cloudy planetary atmosphere. The variations of the sense of the polarization with phase angle and with location on the planetary disk are also consistent with expectations for reflection by clouds.

  9. Externally modulated theranostic nanoparticles

    PubMed Central

    Urban, Cordula; Urban, Alexander S.; Charron, Heather; Joshi, Amit

    2013-01-01

    Externally modulated nanoparticles comprise a rapidly advancing class of cancer nanotherapeutics, which combine the favorable tumor accumulation of nanoparticles, with external spatio-temporal control on therapy delivery via optical, magnetic, or ultrasound modalities. The local control on therapy enables higher tumor treatment efficacy, while simultaneously reducing off-target effects. The nanoparticle interactions with external fields have an additional advantage of frequently generating an imaging signal, and thus such agents provide theranostic (both diagnostic and therapeutic) capabilities. In this review, we classify the emerging externally modulated theranostic nanoparticles according to the mode of external control and describe the physiochemical mechanisms underlying the external control of therapy, and illustrate the major embodiments of nanoparticles in each class with proven biological efficacy: (I) electromagnetic radiation in visible and near-infrared range is being exploited for gold based and carbon nanostructures with tunable surface plasmon resonance (SPR) for imaging and photothermal therapy (PTT) of cancer, photochemistry based manipulations are employed for light sensitive liposomes and porphyrin based nanoparticles; (II) Magnetic field based manipulations are being developed for iron-oxide based nanostructures for magnetic resonance imaging (MRI) and magnetothermal therapy; (III) ultrasound based methods are primarily being employed to increase delivery of conventional drugs and nanotherapeutics to tumor sites. PMID:24834381

  10. Modal radiation patterns of baffled circular plates and membranes.

    PubMed

    Christiansen, Thomas Lehrmann; Hansen, Ole; Thomsen, Erik Vilain; Jensen, Jørgen Arendt

    2014-05-01

    The far field velocity potential and radiation pattern of baffled circular plates and membranes are found analytically using the full set of modal velocity profiles derived from the corresponding equation of motion. The derivation is valid for a plate or membrane subjected to an external excitation force, which is used as a sound receiver in any medium or as a sound transmitter in a gaseous medium. A general, concise expression is given for the radiation pattern of any mode of the membrane and the plate with arbitrary boundary conditions. Specific solutions are given for the four special cases of a plate with clamped, simply supported, and free edge boundary conditions as well as for the membrane. For all non-axisymmetric modes, the velocity potential along the axis of the radiator is found to be strictly zero. In the long wavelength limit, the radiation pattern of all axisymmetric modes approaches that of a monopole, while the non-axisymmetric modes exhibit multipole behavior. Numerical results are also given, demonstrating the implications of having non-axisymmetric excitation using both a point excitation with varying eccentricity and a homogeneous excitation acting on half of the circular radiator. PMID:24815236

  11. Improving wave-packet revivals in circular billiards by applying constant magnetic fields

    SciTech Connect

    Delben, G. J.; Gusso, A.; Luz, M. G. E. da

    2006-05-15

    We show that the revivals structure of Gaussian wave packets for a charged particle with nonzero linear momentum placed in a circular billiard can be considerably improved by applying a perpendicular constant magnetic field of correct chosen intensity. To obtain the desired enhancement, the field must be turned on only at certain time values. We also briefly investigate how the shape of the evoluted packet at the revivals, with and without an external B, compares with the initial state.

  12. Circular Data Images for Directional Data

    NASA Technical Reports Server (NTRS)

    Morpet, William J.

    2004-01-01

    Directional data includes vectors, points on a unit sphere, axis orientation, angular direction, and circular or periodic data. The theoretical statistics for circular data (random points on a unit circle) or spherical data (random points on a unit sphere) are a recent development. An overview of existing graphical methods for the display of directional data is given. Cross-over occurs when periodic data are measured on a scale for the measurement of linear variables. For example, if angle is represented by a linear color gradient changing uniformly from dark blue at -180 degrees to bright red at +180 degrees, the color image will be discontinuous at +180 degrees and -180 degrees, which are the same location. The resultant color would depend on the direction of approach to the cross-over point. A new graphical method for imaging directional data is described, which affords high resolution without color discontinuity from "cross-over". It is called the circular data image. The circular data image uses a circular color scale in which colors repeat periodically. Some examples of the circular data image include direction of earth winds on a global scale, rocket motor internal flow, earth global magnetic field direction, and rocket motor nozzle vector direction vs. time.

  13. 5 CFR 1310.3 - Availability of circulars.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Availability of circulars. 1310.3 Section 1310.3 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES OMB CIRCULARS § 1310.3 Availability of circulars. Copies of individual circulars are available at OMB's Internet home page; you...

  14. 5 CFR 1310.5 - List of current circulars.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false List of current circulars. 1310.5 Section 1310.5 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES OMB CIRCULARS § 1310.5 List of current circulars. The following list includes all circulars in effect as of December 1,...

  15. 5 CFR 1310.5 - List of current circulars.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false List of current circulars. 1310.5 Section 1310.5 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES OMB CIRCULARS § 1310.5 List of current circulars. The following list includes all circulars in effect as of December 1,...

  16. 5 CFR 1310.5 - List of current circulars.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false List of current circulars. 1310.5 Section 1310.5 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES OMB CIRCULARS § 1310.5 List of current circulars. The following list includes all circulars in effect as of December 1,...

  17. 5 CFR 1310.5 - List of current circulars.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false List of current circulars. 1310.5 Section 1310.5 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES OMB CIRCULARS § 1310.5 List of current circulars. The following list includes all circulars in effect as of December 1,...

  18. 5 CFR 1310.5 - List of current circulars.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false List of current circulars. 1310.5 Section 1310.5 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES OMB CIRCULARS § 1310.5 List of current circulars. The following list includes all circulars in effect as of December 1,...

  19. 39 CFR 233.2 - Circulars and rewards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Circulars and rewards. 233.2 Section 233.2 Postal Service UNITED STATES POSTAL SERVICE ORGANIZATION AND ADMINISTRATION INSPECTION SERVICE AUTHORITY § 233.2 Circulars and rewards. (a) Wanted circulars. The Inspection Service issues wanted circulars to assist...

  20. 5 CFR 1310.3 - Availability of circulars.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Availability of circulars. 1310.3 Section 1310.3 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES OMB CIRCULARS § 1310.3 Availability of circulars. Copies of individual circulars are available at OMB's Internet home page; you...

  1. 39 CFR 233.2 - Circulars and rewards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Circulars and rewards. 233.2 Section 233.2 Postal Service UNITED STATES POSTAL SERVICE ORGANIZATION AND ADMINISTRATION INSPECTION SERVICE AUTHORITY § 233.2 Circulars and rewards. (a) Wanted circulars. The Inspection Service issues wanted circulars to assist in locating and arresting fugitive...

  2. 12 CFR 563g.8 - Use of the offering circular.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Use of the offering circular. 563g.8 Section... § 563g.8 Use of the offering circular. (a) An offering circular or amendment declared effective by the... therein is as of a date not more than 16 months prior to such use. (b) An offering circular filed...

  3. 24 CFR 574.605 - Applicability of OMB circulars.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Federal Requirements § 574.605 Applicability of OMB circulars. The policies, guidelines, and requirements of 24 CFR part 85 (codified pursuant to OMB Circular No. A-102) and OMB Circular No. A-87 apply with... 24 Housing and Urban Development 3 2011-04-01 2010-04-01 true Applicability of OMB circulars....

  4. 24 CFR 574.605 - Applicability of OMB circulars.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Federal Requirements § 574.605 Applicability of OMB circulars. The policies, guidelines, and requirements of 24 CFR part 85 (codified pursuant to OMB Circular No. A-102) and OMB Circular No. A-87 apply with... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Applicability of OMB circulars....

  5. 5 CFR 1310.3 - Availability of circulars.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Availability of circulars. 1310.3 Section 1310.3 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES OMB CIRCULARS § 1310.3 Availability of circulars. Copies of individual circulars are available at OMB's Internet home page; you...

  6. 49 CFR 1544.305 - Security Directives and Information Circulars.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 9 2011-10-01 2011-10-01 false Security Directives and Information Circulars... and Information Circulars. (a) TSA may issue an Information Circular to notify aircraft operators of... operator that receives a Security Directive or Information Circular and each person who...

  7. 12 CFR 563g.8 - Use of the offering circular.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Use of the offering circular. 563g.8 Section... § 563g.8 Use of the offering circular. (a) An offering circular or amendment declared effective by the... therein is as of a date not more than 16 months prior to such use. (b) An offering circular filed...

  8. Metasurface external cavity laser

    SciTech Connect

    Xu, Luyao Curwen, Christopher A.; Williams, Benjamin S.; Hon, Philip W. C.; Itoh, Tatsuo; Chen, Qi-Sheng

    2015-11-30

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  9. Metasurface external cavity laser

    NASA Astrophysics Data System (ADS)

    Xu, Luyao; Curwen, Christopher A.; Hon, Philip W. C.; Chen, Qi-Sheng; Itoh, Tatsuo; Williams, Benjamin S.

    2015-11-01

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  10. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism

    PubMed Central

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D.; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J.; Mancuso, Christopher A.; Hogle, Craig W.; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L.; Dorney, Kevin M.; Chen, Cong; Shpyrko, Oleg G.; Fullerton, Eric E.; Cohen, Oren; Oppeneer, Peter M.; Milošević, Dejan B.; Becker, Andreas; Jaroń-Becker, Agnieszka A.; Popmintchev, Tenio; Murnane, Margaret M.; Kapteyn, Henry C.

    2015-01-01

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform. PMID:26534992

  11. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism.

    PubMed

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J; Mancuso, Christopher A; Hogle, Craig W; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L; Dorney, Kevin M; Chen, Cong; Shpyrko, Oleg G; Fullerton, Eric E; Cohen, Oren; Oppeneer, Peter M; Milošević, Dejan B; Becker, Andreas; Jaroń-Becker, Agnieszka A; Popmintchev, Tenio; Murnane, Margaret M; Kapteyn, Henry C

    2015-11-17

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform. PMID:26534992

  12. 76 FR 62148 - Title VI; Proposed Circular, Environmental Justice; Proposed Circular

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-06

    ... Circular'' (76 FR 60593) and ``Environmental Justice; Proposed Circular'' (76 FR 60590). Corrections The... program questions, Amber Ontiveros, Office of Civil Rights, Federal Transit Administration, 1200 New Jersey Ave., SE., Washington, DC 20590, phone: (202) 366-4018, fax: (202) 366-3809, or e-mail,...

  13. Environmental issues elimination through circular economy

    NASA Astrophysics Data System (ADS)

    Špirková, M.; Pokorná, E.; Šujanová, J.; Samáková, J.

    2016-04-01

    Environmental efforts of European Union are currently going towards circular economy. Tools like Extended Producer Responsibility and Eco-design were established. The circular economy deals with resources availability issue on one hand and waste management on the other hand. There are few pioneering companies all over the world with some kind of circular economy practice. Generally the concept is not very wide-spread. The paper aims to evaluate possibility of transition towards circular economy in Slovak industrial companies. They need to have an active approach to material treatment of their products after usage stage. Innovation is another important pre-condition for the transition. Main problem of current cradle to grave system is landfilling of valuable materials after one cycle of usage. Their potential value for next manufacturing cycles is lost. Companies may do not see connection between waste management and material resource prices and volatility of supplies. Municipalities are responsible for municipal waste collection and treatment in Slovakia. The circular economy operates by cradle to cradle principle. Company manages material flow until the material comes back to the beginning of manufacturing process by itself or by another partners. Stable material supplies with quite low costs are provided this way. It is necessary to deal with environmental problems in phase of product design. Questionnaire survey results show on one hand low involvement of industrial companies in waste management area, however on the other hand they are open to environmental innovations in future.

  14. Repetitive elements regulate circular RNA biogenesis

    PubMed Central

    Wilusz, Jeremy E

    2015-01-01

    It was long assumed that eukaryotic precursor mRNAs (pre-mRNAs) are almost always spliced to generate a linear mRNA that is subsequently translated to produce a protein. However, it is now clear that thousands of protein-coding genes can be non-canonically spliced to produce circular noncoding RNAs, some of which are expressed at much higher levels than their associated linear mRNAs. How then does the splicing machinery decide whether to generate a linear mRNA or a circular RNA? Recent work has revealed that intronic repetitive elements, including sequences derived from transposons, are critical regulators of this decision. In most cases, circular RNA biogenesis appears to be initiated when complementary sequences from 2 different introns base pair to one another. This brings the splice sites from the intervening exon(s) into close proximity and facilitates the backsplicing event that generates the circular RNA. As many pre-mRNAs contain multiple intronic repeats, distinct circular transcripts can be produced depending on which repeats base pair to one another. Intronic repeats are thus critical regulatory sequences that control the functional output of their host genes, and potentially cause the functions of protein-coding genes to be highly divergent across species. PMID:26442181

  15. Circular and Elliptic Submerged Impinging Water Jets

    NASA Astrophysics Data System (ADS)

    Claudey, Eric; Benedicto, Olivier; Ravier, Emmanuel; Gutmark, Ephraim

    1999-11-01

    Experiments and CFD have been performed to study circular and elliptic jets in a submerged water jet facility. The tests included discharge coefficient measurement to evaluate pressure losses encountered in noncircular nozzles compared to circular ones. Three-dimensional pressure mappings on the impingement surface and PIV measurement of the jet mean and turbulent velocity have been performed at different compound impingement angles relative to the impingement surface and at different stand-off distances. The objective was to investigate the effect of the non-circular geometry on the flow field and on the impact region. The tests were performed in a close loop system in which the water was pumped through the nozzles into a clear Plexiglas tank. The Reynolds numbers were typically in the range of 250000. Discharge coefficients of the elliptic nozzle was somewhat lower than that of the circular jet but spreading rate and turbulence level were higher. Pressure mapping showed that the nozzle exit geometry had an effect on the pressure distribution in the impact region and that high-pressure zones were generated at specific impact points. PIV measurements showed that for a same total exit area, the elliptic jets affected a surface area that is 8the equivalent circular. The turbulence level in the elliptic jet tripled due to the nozzle design. Results of the CFD model were in good agreement with the experimental data.

  16. A broadband, circular-polarization selective surface

    NASA Astrophysics Data System (ADS)

    Momeni Hasan Abadi, Seyed Mohamad Amin; Behdad, Nader

    2016-06-01

    We introduce a new technique for designing wideband circular-polarization selective surfaces (CPSSs) based on anisotropic miniaturized element frequency selective surfaces. The proposed structure is a combination of two linear-to-circular polarization converters sandwiching a linear polarizer. This CPSS consists of a number of metallic layers separated from each other by thin dielectric substrates. The metallic layers are in the form of two-dimensional arrays of subwavelength capacitive patches and inductive wire grids with asymmetric dimensions and a wire grid polarizer with sub-wavelength period. The proposed device is designed to offer a wideband circular-polarization selection capability allowing waves with left-hand circular polarization to pass through while rejecting those having right-hand circular polarization. A synthesis procedure is developed that can be used to design the proposed CPSS based on its desired band of operation. Using this procedure, a prototype of the proposed CPSS operating in the 12-18 GHz is designed. Full-wave electromagnetic simulations are used to predict the response of this structure. These simulation results confirm the validity of the proposed design concept and synthesis procedure and show that proposed CPSS operates within a fractional bandwidth of 40% with a co-polarization transmission discrimination of more than 15 dB. Furthermore, the proposed design is shown to be capable of providing an extremely wide field of view of ±60°.

  17. Nanofocusing in circular sector-like nanoantennas.

    PubMed

    Zenin, Vladimir A; Pors, Anders; Han, Zhanghua; Eriksen, René L; Volkov, Valentyn S; Bozhevolnyi, Sergey I

    2014-05-01

    Gold circular sector-like nanoantennas (with a radius of 500 nm and a taper angle of 60°, 90°, and 120°) on glass are investigated in a near-infrared wavelength range (900 - 2100 nm). Amplitude- and phase-resolved near-field images of circular sector-like antenna modes at telecom wavelength feature a concentric circular line of phase contrast, demonstrating resonant excitation of a standing wave of counter-propagating surface plasmons, travelling between a tip and opposite circular edge of the antenna. Transmission spectra obtained in the range 900 - 2100 nm are in good agreement with numerical simulations, revealing the main feature of this antenna configuration, viz., the resonance wavelength, in contrast to triangular antennas, does not depend on the taper angle and is determined only by the sector radius. This feature together with a robust and easily predictable frequency response makes circular sector-like nanoantennas very promising for implementing bowtie antennas and attractive for many applications. PMID:24921736

  18. Literature: External Forms.

    ERIC Educational Resources Information Center

    Regional Curriculum Project, Atlanta, GA.

    This curriculum guide, developed as part of a total English curriculum for pre-kindergarten through grade 10, suggests that students can best understand literature by understanding its recurring external forms or genres, and includes (1) an overview describing the four literary genres of drama, narrative poetry, narrative fiction, and lyric poetry…

  19. External Environmental Forecast.

    ERIC Educational Resources Information Center

    Lapin, Joel D.

    Representing current viewpoints of academics, futures experts, and social observers, this external environmental forecast presents projections and information of particular relevance to the future of Catonsville Community College. The following topics are examined: (1) population changes and implications for higher education; (2) state and local…

  20. External Otitis (Swimmer's Ear)

    MedlinePlus

    ... drops, keeping water out of the ear, and pain relievers are the most common forms of treatment. External otitis may involve the entire canal, as ... does not allow fungus to grow as well. Treatment of boils depends on ... relievers, such as oxycodone with acetaminophen , can be given ...

  1. Circular Proteins from Plants and Fungi*

    PubMed Central

    Göransson, Ulf; Burman, Robert; Gunasekera, Sunithi; Strömstedt, Adam A.; Rosengren, K. Johan

    2012-01-01

    Circular proteins, defined as head-to-tail cyclized polypeptides originating from ribosomal synthesis, represent a novel class of natural products attracting increasing interest. From a scientific point of view, these compounds raise questions of where and why they occur in nature and how they are formed. From a rational point of view, these proteins and their structural concept may be exploited for crop protection and novel pharmaceuticals. Here, we review the current knowledge of three protein families: cyclotides and circular sunflower trypsin inhibitors from the kingdom of plants and the Amanita toxins from fungi. A particular emphasis is placed on their biological origin, structure, and activity. In addition, the opportunity for discovery of novel circular proteins and recent insights into their mechanism of action are discussed. PMID:22700984

  2. Optics modules for circular accelerator design

    SciTech Connect

    Brown, K.L.; Servranckx, R.V.

    1986-05-01

    The first-order differential equations of motion for a single particle in a closed circular machine are solved, introducing the concepts of phase shift, beta functions, and the Courant-Snyder invariant. The transfer matrix between two points in the machine is derived as a function of the phase shift and the parameters contained in the Courant-Snyder invariant. Typical optical modules used in circular machine designs are introduced and related to their characteristic transfer matrix elements, the phase shift through them, and the Courant-Snyder-Twiss parameters. The systematics of some elementary phase ellipse matching problems between optical modules are discussed. Second-order optical modules are discussed, including how they are used to provide the momentum bandwidth needed for the design of a typical circular machine. (LEW)

  3. Circularly symmetric light scattering from nanoplasmonic spirals.

    PubMed

    Trevino, Jacob; Cao, Hui; Dal Negro, Luca

    2011-05-11

    In this paper, we combine experimental dark-field imaging, scattering, and fluorescence spectroscopy with rigorous electrodynamics calculations in order to investigate light scattering from planar arrays of Au nanoparticles arranged in aperiodic spirals with diffuse, circularly symmetric Fourier space. In particular, by studying the three main types of Vogel's spirals fabricated by electron-beam lithography on quartz substrates, we demonstrate polarization-insensitive planar light diffraction in the visible spectral range. Moreover, by combining dark-field imaging with analytical multiparticle calculations in the framework of the generalized Mie theory, we show that plasmonic spirals support distinctive structural resonances with circular symmetry carrying orbital angular momentum. The engineering of light scattering phenomena in deterministic structures with circular Fourier space provides a novel strategy for the realization of optical devices that fully leverage on enhanced, polarization-insensitive light-matter coupling over planar surfaces, such as thin-film plasmonic solar cells, plasmonic polarization devices, and optical biosensors. PMID:21466155

  4. Reconnaissance with slant plane circular SAR imaging.

    PubMed

    Soumekh, M

    1996-01-01

    This paper presents a method for imaging from the slant plane data collected by a synthetic aperture radar (SAR) over the full rotation or a partial segment of a circular flight path. A Fourier analysis for the Green's function of the imaging system is provided. This analysis is the basis of an inversion for slant plane circular SAR data. The reconstruction algorithm and resolution for this SAR system are outlined. It is shown that the slant plane circular SAR, unlike the slant plane linear SAR, has the capability to extract three-dimensional imaging information of a target scene. The merits of the algorithm are demonstrated via a simulated target whose ultra wideband foliage penetrating (FOPEN) or ground penetrating (GPEN) ultrahigh frequency (UHF) radar signature varies with the radar's aspect angle. PMID:18285213

  5. Charged Particle Optics in Circular Higgs Factory

    SciTech Connect

    Cai, Yunhai

    2015-02-26

    Similar to a super B-factory, a circular Higgs factory will require strong focusing systems near the interaction points and a low-emittance lattice in arcs to achieve a factory luminosity. At electron beam energy of 120 GeV, beamstrahlung effects during the collision pose an additional challenge to the collider design. In particular, a large momentum acceptance at 2 percent level is necessary to retain an adequate beam lifetime. This turns out to be the most challenging aspect in the design of circular Higgs factory. In this paper, an example will be provided to illustrate the beam dynamics in circular Higgs factory, emphasizing on the chromatic optics. Basic optical modules and advanced analysis will be presented. Most important, we will show that 2% momentum aperture is achievable

  6. Time-resolved circularly polarized protein phosphorescence.

    PubMed Central

    Schauerte, J A; Steel, D G; Gafni, A

    1992-01-01

    The existence of circular polarization in room-temperature protein phosphorescence is demonstrated, and time-resolved circularly polarized phosphorescence (TR-CPP) is used to characterize unique tryptophan environments in multitryptophan proteins. Circularly polarized luminescence studies provide information regarding the excited state chirality of a lumiphore which can be used to extract sensitive structural information. It is shown by time resolving the circular polarization that it is possible to correlate the excited state chirality with unique decay components in a multiexponential phosphorescence decay profile. The present study presents a concurrent analysis of room-temperature time-resolved phosphorescence and TR-CPP of bacterial glucose-6-phosphate dehydrogenase as well as those of horse liver alcohol dehydrogenase. Only one of the two tryptophan residues per subunit of dimeric alcohol dehydrogenase is believed to phosphorescence, while the dimeric glucose-6-phosphate dehydrogenase has eight tryptophan residues per subunit and shows a corresponding complexity in its phosphorescence decay profile. The anisotropy factor [g(em) = delta I/(Itotal/2); delta I = Ileft circular-Iright circular] for alcohol dehydrogenase is time independent, suggesting a unique excited state chirality. The phosphorescence decay of glucose-6-phosphate dehydrogenase can be well fitted with four exponential terms of 4, 23, 76, and 142 msec, and the TR-CPP of this enzyme shows a strong time dependence that can be resolved into four individual time-independent anisotropy factors of -4.0, -2.1, +6.5, and +6.9 (x10(-3)), each respectively associated with one of the four lifetime components. These results demonstrate how the use of TR-CPP can facilitate the study of proteins with multiple lumiphores. PMID:1438204

  7. Circularly Polarized Luminescence from Simple Organic Molecules.

    PubMed

    Sánchez-Carnerero, Esther M; Agarrabeitia, Antonia R; Moreno, Florencio; Maroto, Beatriz L; Muller, Gilles; Ortiz, María J; de la Moya, Santiago

    2015-09-21

    This article aims to show the identity of "circularly polarized luminescent active simple organic molecules" as a new concept in organic chemistry due to the potential interest of these molecules, as availed by the exponentially growing number of research articles related to them. In particular, it describes and highlights the interest and difficulty in developing chiral simple (small and non-aggregated) organic molecules able to emit left- or right-circularly polarized light efficiently, the efforts realized up to now to reach this challenging objective, and the most significant milestones achieved to date. General guidelines for the preparation of these interesting molecules are also presented. PMID:26136234

  8. Computing Scattering Matrices For Circular Waveguides

    NASA Technical Reports Server (NTRS)

    Hoppe, Daniel J.

    1990-01-01

    Scattering Matrix Program for Circular Waveguide Junctions computes scattering matrix for series of circular waveguide sections. Sections must have same axis, but radius and length of each section completely arbitrary. Devices analyzed include simple waveguide step discontinuity like that used in a dual-mode horn, stepped matching section, or corrugated waveguide section with constant or varying slot depth. Certain types of corrugated horns also analyzed with program. Mathematical model used in program accurately predicts reflection and transmission characteristics of such devices, taking into account excitation of modes of higher order as well as multiple reflections and energy stored at each discontinuity. Written in FORTRAN 77.

  9. Scalar wave diffraction from a circular aperture

    SciTech Connect

    Cerjan, C.

    1995-01-25

    The scalar wave theory is used to evaluate the expected diffraction patterns from a circular aperture. The standard far-field Kirchhoff approximation is compared to the exact result expressed in terms of oblate spheroidal harmonics. Deviations from an expanding spherical wave are calculated for circular aperture radius and the incident beam wavelength using suggested values for a recently proposed point diffractin interferometer. The Kirchhoff approximation is increasingly reliable in the far-field limit as the aperture radius is increased, although significant errors in amplitude and phase persist.

  10. Rotatable non-circular forebody flow controller

    NASA Technical Reports Server (NTRS)

    Moskovitz, Cary A. (Inventor)

    1991-01-01

    The invention is a rotatable, non-circular forebody flow controller. The apparatus comprises a small geometric device located at a nose of a forebody of an aircraft and a non-circular cross-sectional area that extends toward the apex of the aircraft. The device is symmetrical about a reference plane and preferably attaches to an axle which in turn attaches to a rotating motor. The motor rotates the device about an axis of rotation. Preferably, a control unit connected to an aircraft flight control computer signals to the rotating motor the proper rotational positioning of the geometric device.

  11. Beam scanning reflectarray antenna with circular polarization

    NASA Technical Reports Server (NTRS)

    Huang, John (Inventor); Pogorzelski, Ronald J. (Inventor)

    2000-01-01

    A novel means of scanning a circularly polarized reflectarray antenna. The reflectarray is an array of metallic elements arranged on a surface designed to compensate for the various path lengths of the optical rays from an illuminating feed to the reflecting surface and then to the antenna aperture. With appropriate design, the phase in the aperture can be made to vary linearly in any desired direction and also to produce a radiated beam normal to the constant phase surface. In the case of circular polarization, this path length compensation can be accomplished by rotation of the individual elements.

  12. [External ear melanoma].

    PubMed

    Amando García, L; Suárez Nieto, C; Madrigal Rubiales, B; García García, J

    2003-02-01

    Cutaneous melanomas are the tumours that have increased more their incidence in the last fifty years. Melanomas arising from the external auditory canal are extraordinariously unfrequent. These tumours show an aggressive and silent behaviour, and due to this the diagnosis is frequently made in an advanced stage. A male with a malignant melanoma arising from his left external auditory canal was attended in our department, suspecting an epidermoid carcinoma. The clinical findings and the extension of the lesion required a lateral temporal bone resection, parotidectomy and neck dissection to achieve a total resection. We present a review of the literature about this entity and an analysis of the incidence, significance of the lymph node metastases and value of the elective neck dissection. PMID:12802982

  13. Externally triggered microcapsules

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2011-01-01

    Disclosed are microcapsules comprising a polymer shell enclosing one or more immiscible liquid phases in which a drug or drug precursor are contained in a liquid phase. The microparticles also contain magnetic particles that can be heated by application of an external magnetic field and thus heated to a predetermined Curie temperature. Heating of the particles melts the polymer shell and releases the drug without causing heating of surrounding tissues.

  14. Compliance Supplement. OMB Circular A-133.

    ERIC Educational Resources Information Center

    Office of Management and Budget, Washington, DC.

    This document is a supplement to Circular A-133 (1990) from the Office of Management and Budget (OMB), which extended the government's "single audit process" for agencies that administer federal financial assistance programs to higher education institutions and non-profit organizations. This supplement is based on the 1996 Amendments (the Single…

  15. Home Sewage Disposal. Special Circular 212.

    ERIC Educational Resources Information Center

    Wooding, N. Henry

    This circular provides current information for homeowners who must repair or replace existing on-lot sewage disposal systems. Site requirements, characteristics and preparation are outlined for a variety of alternatives such as elevated sand mounds, sand-lined beds and trenches, and oversized absorption area. Diagrams indicating construction…

  16. 78 FR 14620 - Joint Development: Proposed Circular

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-06

    ... published guidance on the eligibility of joint development activities for FTA funding. 72 FR 5788 (Feb. 7... review DOT's complete Privacy Act Statement published in the Federal Register on April 11, 2000 (65 FR... Federal Transit Administration Joint Development: Proposed Circular AGENCY: Federal Transit...

  17. Cold Rydberg atoms in circular states

    NASA Astrophysics Data System (ADS)

    Anderson, David; Schwarzkopf, Andrew; Raithel, Georg

    2012-06-01

    Circular-state Rydberg atoms are interesting in that they exhibit a unique combination of extraordinary properties; long lifetimes (˜n^5), large magnetic moments (l=|m|=n-1) and no first order Stark shift. Circular states have found applications in cavity quantum electrodynamics and precision measurements [1,2], among other studies. In this work we present the production of circular states in an atom trapping apparatus using an adiabatic state-switching method (the crossed-field method [3]). To date, we have observed lifetimes of adiabatically prepared states of several milliseconds. Their relatively large ionization electric fields have been verified by time-of-flight signatures of ion trajectories. We intend to explore the magnetic trapping of circular state Rydberg atoms, as well as their production and interaction properties in ultra-cold and degenerate samples.[4pt] [1] P. Bertet et al., Phys. Rev. Lett., 88, 14 (2002)[0pt] [2] M. Brune et al., Phys. Rev. Lett., 72, 21 (1994)[0pt] [3] D. Delande and J.C. Gay, Europhys. Lett., 5, 303-308 (1988).

  18. Magnifying Devices: A Resource Guide. Reference Circular.

    ERIC Educational Resources Information Center

    Strauss, Carol, Comp.

    The devices listed in this reference circular are designed to assist people who have visual impairments by magnifying objects and print or graphic materials. Before buying a magnification device, one should consult a low-vision specialist to determine the level of usable vision, the power of magnification needed for a particular eye condition and…

  19. Articulated Multimedia Physics, Lesson 10, Circular Motion.

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

    As the tenth lesson of the Articulated Multimedia Physics Course, instructional materials relating to circular motion are presented in this study guide. The topics are concerned with instantaneous velocity, centripetal force, centrifugal force, and satellite paths. The content is arranged in scrambled form, and the use of matrix transparencies is…

  20. Non-Circular Wheels: Reuleaux and Squares

    ERIC Educational Resources Information Center

    Mills, Allan

    2011-01-01

    Circular wheels are so familiar on vehicles of all types that it is seldom realized that alternatives do exist. This short non-mathematical article describes Reuleaux and square wheels that, rolling along appropriate tracks, can maintain a moving platform at a constant height. Easily made working models lend themselves to demonstrations at science…

  1. 77 FR 52116 - Title VI; Final Circular

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-28

    ... September 29, 2011, Federal Register notice (76 FR 60593), and provides information regarding implementation... Address Environmental Justice in Minority Populations and Low-Income Populations,'' 77 FR 27534, May 10...-0055) (77 FR 42077, July 17, 2012). The EJ Circular is available on FTA's Web site here:...

  2. 21 CFR 606.122 - Instruction circular.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... shall contain: (1) Instructions to administer a suitable plasma volume expander if Red Blood Cells are...: (1) The approximate volume of plasma from which a sample unit of Platelets is prepared. (2... container. (m) For Plasma, the instruction circular shall contain: (1) A warning against further...

  3. 17 CFR 230.253 - Offering circular.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 2 2013-04-01 2013-04-01 false Offering circular. 230.253 Section 230.253 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION GENERAL RULES AND REGULATIONS, SECURITIES ACT OF 1933 Regulation A-Conditional Small Issues Exemption § 230.253...

  4. 17 CFR 230.253 - Offering circular.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Offering circular. 230.253 Section 230.253 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION GENERAL RULES AND REGULATIONS, SECURITIES ACT OF 1933 Regulation A-Conditional Small Issues Exemption § 230.253...

  5. 17 CFR 230.253 - Offering circular.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 2 2012-04-01 2012-04-01 false Offering circular. 230.253 Section 230.253 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION GENERAL RULES AND REGULATIONS, SECURITIES ACT OF 1933 Regulation A-Conditional Small Issues Exemption § 230.253...

  6. 17 CFR 230.253 - Offering circular.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Offering circular. 230.253 Section 230.253 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION GENERAL RULES AND REGULATIONS, SECURITIES ACT OF 1933 Regulation A-Conditional Small Issues Exemption § 230.253...

  7. Using Pesticides Safely. Special Circular 296.

    ERIC Educational Resources Information Center

    Hock, W. K.

    The use of pesticides is necessary to aid in the production of food, feed and fiber, and is equally important in the control of home garden and household pests, but correct use is critical in preventing injury to persons, animals, and plants. This circular contains information on State of Pennsylvania and federal pesticide laws; different types of…

  8. Helically corrugated circular waveguides as antenna feeders

    NASA Astrophysics Data System (ADS)

    Jecko, F.; Papiernik, A.

    1983-07-01

    Rotation of the plane of polarization of the TE(11)-mode is predicted and observed in a helically corrugated circular waveguide. Rotation is suppressed by a longitudinal deformation produced on the corrugation. This modified structure can be used as an antenna feeder with low losses.

  9. Combustor with non-circular head end

    SciTech Connect

    Kim, Won -Wook; McMahan, Kevin Weston

    2015-09-29

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a head end with a non-circular configuration, a number of fuel nozzles positioned about the head end, and a transition piece extending downstream of the head end.

  10. Circular tapered tape fabrication: Final report

    SciTech Connect

    Stockdale, D.A.

    1988-04-01

    A new approach to producing tapered tapes has been developed involving generating a tapered tape in a circular configuration on a lathe rather than a mill. This approach is more cost-effective and the redesigned slot configuration induced less stress on the tapes during installation and removal.

  11. Circular Vibration Planing of Inconel 718

    NASA Astrophysics Data System (ADS)

    Hettiarachchi, Nandita Kalyanakumara; Moriwaki, Toshimichi; Shibasaka, Toshiro; Nakamoto, Keiichi

    Circular vibration milling (CVM) is achieved by vibrating a milling cutter about the machine tool spindle axis in a circular path, in addition to its rotary motion. CVM has been proven capable of producing better surface finishes on difficult to cut materials. However, the CVM process is far slower than conventional milling process. In circular vibration planing (CVP) process, the cutting tool is clamped without rotation and fed at a speed comparable to the feed speed of conventional milling. By superimposing circular vibration motion, necessary cutting speed could be achieved keeping the feed speed at realistic values. Inconel 718 was machined by CVP and conventional milling at a similar feed rate. It was observed that CVP could reduce tool wear and hence produce better surface finishes than conventional milling. A geometric simulation showed a major difference between uncut chip shapes of the two processes. The difference of uncut chip shapes suggests that in CVP process, less rubbing occurs between tool flank face and work before the tool penetrates in to the work to form a chip. The reduced rubbing of the flank face is proposed as the reson for reduced tool wear in CVP when compared with conventional milling.

  12. Energetically efficient proportional-integral-differential (PID) control of wake vortices behind a circular cylinder

    NASA Astrophysics Data System (ADS)

    Das, Pramode K.; Mathew, Sam; Shaiju, A. J.; Patnaik, B. S. V.

    2016-02-01

    The control of vortex shedding behind a circular cylinder is a precursor to a wide range of external shear flow problems in engineering, in particular the flow-induced vibrations. In the present study, numerical simulation of an energetically efficient active flow control strategy is proposed, for the control of wake vortices behind a circular cylinder at a low Reynolds number of 100. The fluid is assumed to be incompressible and Newtonian with negligible variation in properties. Reflectionally symmetric controllers are designed such that, they are located on a small sector of the cylinder over which, tangential sliding mode control is imparted. In the field of modern controls, proportional (P), integral (I) and differential (D) control strategies and their numerous combinations are extremely popular in industrial practice. To impart suitable control actuation, the vertically varying lift force on the circular cylinder, is synthesised for the construction of an error term. Four different types of controllers considered in the present study are, P, I, PI and PID. These controllers are evaluated for their energetic efficiency and performance. A linear quadratic optimal control problem is formulated, to minimise the cost functional. By performing detailed simulations, it was observed that, the system is energetically efficient, even when the twin eddies are still persisting behind the circular cylinder. To assess the adaptability of the controllers, the actuators were switched on and off to study their dynamic response.

  13. Radial Internal Material Handling System (RIMS) for Circular Habitat Volumes

    NASA Technical Reports Server (NTRS)

    Howe, Alan S.; Haselschwardt, Sally; Bogatko, Alex; Humphrey, Brian; Patel, Amit

    2013-01-01

    On planetary surfaces, pressurized human habitable volumes will require a means to carry equipment around within the volume of the habitat, regardless of the partial gravity (Earth, Moon, Mars, etc.). On the NASA Habitat Demonstration Unit (HDU), a vertical cylindrical volume, it was determined that a variety of heavy items would need to be carried back and forth from deployed locations to the General Maintenance Work Station (GMWS) when in need of repair, and other equipment may need to be carried inside for repairs, such as rover parts and other external equipment. The vertical cylindrical volume of the HDU lent itself to a circular overhead track and hoist system that allows lifting of heavy objects from anywhere in the habitat to any other point in the habitat interior. In addition, the system is able to hand-off lifted items to other material handling systems through the side hatches, such as through an airlock. The overhead system consists of two concentric circle tracks that have a movable beam between them. The beam has a hoist carriage that can move back and forth on the beam. Therefore, the entire system acts like a bridge crane curved around to meet itself in a circle. The novelty of the system is in its configuration, and how it interfaces with the volume of the HDU habitat. Similar to how a bridge crane allows coverage for an entire rectangular volume, the RIMS system covers a circular volume. The RIMS system is the first generation of what may be applied to future planetary surface vertical cylinder habitats on the Moon or on Mars.

  14. A simple circular-polarized antenna: Circular waveguide horn coated with lossy magnetic material

    NASA Technical Reports Server (NTRS)

    Lee, C. S.; Lee, S. W.; Justice, D. W.

    1986-01-01

    A circular waveguide horn coated with a lossy material in its interior wall can be used as an alternative to a corrugated waveguide for radiating a circularly polarized (CP) field. To achieve good CP radiation, the diameter of the structure must be larger than the free-space wavelength, and the coating material must be sufficiently lossy and magnetic. This device is cheaper and lighter in weight than the corrugated one.

  15. A simple circular-polarized antenna: Circular waveguide horn coated with lossy magnetic material

    NASA Astrophysics Data System (ADS)

    Lee, Choon S.; Justice, D. W.; Lee, Shung-Wu

    1988-02-01

    It is shown that a circular waveguide horn coated with a lossy material in its interior wall can be used as an alternative to a corrugated waveguide for radiating a circularly polarized (CP) field. To achieve good CP radiation, the diameter of the structure must be larger than the free-space wavelength, and the coating material must be sufficiently lossy and magnetic. The device is cheaper and lighter in weight than the corrugated one.

  16. A simple circular-polarized antenna: Circular waveguide horn coated with lossy magnetic material

    NASA Astrophysics Data System (ADS)

    Lee, C. S.; Lee, S. W.; Justice, D. W.

    1986-08-01

    A circular waveguide horn coated with a lossy material in its interior wall can be used as an alternative to a corrugated waveguide for radiating a circularly polarized (CP) field. To achieve good CP radiation, the diameter of the structure must be larger than the free-space wavelength, and the coating material must be sufficiently lossy and magnetic. This device is cheaper and lighter in weight than the corrugated one.

  17. A simple circular-polarized antenna: Circular waveguide horn coated with lossy magnetic material

    NASA Technical Reports Server (NTRS)

    Lee, Choon S.; Justice, D. W.; Lee, Shung-Wu

    1988-01-01

    It is shown that a circular waveguide horn coated with a lossy material in its interior wall can be used as an alternative to a corrugated waveguide for radiating a circularly polarized (CP) field. To achieve good CP radiation, the diameter of the structure must be larger than the free-space wavelength, and the coating material must be sufficiently lossy and magnetic. The device is cheaper and lighter in weight than the corrugated one.

  18. Progressive External Ophthalmoplegia.

    PubMed

    McClelland, Collin; Manousakis, Georgios; Lee, Michael S

    2016-06-01

    Progressive external ophthalmoplegia (PEO), marked by progressive bilateral ptosis and diffuse reduction in ocular motility, represents a finding of mitochondrial myopathy rather than a true diagnosis. PEO often occurs with other systemic features of mitochondrial dysfunction that can cause significant morbidity and mortality. Accurate and early recognition of PEO is paramount for the optimal care of these patients. We present an evidence-based review of the presenting neuro-ophthalmic features, differential diagnosis, diagnostic tools, systemic implications, and treatment options for isolated PEO and other PEO-associated mitochondrial syndromes. PMID:27072953

  19. DIRBE External Calibrator (DEC)

    NASA Technical Reports Server (NTRS)

    Wyatt, Clair L.; Thurgood, V. Alan; Allred, Glenn D.

    1987-01-01

    Under NASA Contract No. NAS5-28185, the Center for Space Engineering at Utah State University has produced a calibration instrument for the Diffuse Infrared Background Experiment (DIRBE). DIRBE is one of the instruments aboard the Cosmic Background Experiment Observatory (COBE). The calibration instrument is referred to as the DEC (Dirbe External Calibrator). DEC produces a steerable, infrared beam of controlled spectral content and intensity and with selectable point source or diffuse source characteristics, that can be directed into the DIRBE to map fields and determine response characteristics. This report discusses the design of the DEC instrument, its operation and characteristics, and provides an analysis of the systems capabilities and performance.

  20. External split field generator

    SciTech Connect

    Thundat, Thomas George; Van Neste, Charles W.; Vass, Arpad Alexander

    2012-02-21

    A generator includes a coil disposed about a core. A first stationary magnetic field source may be disposed on a first end portion of the core and a second stationary magnetic field source may be disposed on a second end portion of core. The first and second stationary magnetic field sources apply a stationary magnetic field to the coil. An external magnetic field source may be disposed outside the coil to apply a moving magnetic field to the coil. Electrical energy is generated in response to an interaction between the coil, the moving magnetic field, and the stationary magnetic field.

  1. Topologically non-linked circular duplex DNA.

    PubMed

    Biegeleisen, Ken

    2002-05-01

    The discovery of circular DNA, over 30 years ago, introduced an element of uneasiness in what had been, up to that point, the almost picture-perfect story of the elucidation of the molecular biology of heredity. If DNA indeed has the Watson-Crick right-handed helical secondary structure, then in circular DNA, thousands, or perhaps even millions of twists must be removed in each generation, and re-wound in the next generation. Although enzyme systems adequate for this task have long since been found and characterized, there have nevertheless arisen a number of proposals for alternative DNA structures in which the strands are topologically non-linked, so that they might separate during replication without having to be unwound. These structures have generally been put forth as theory only, and have been largely unaccompanied by experimental evidence to support their applicability to native DNA from living systems. Recently, however, a report has emerged suggesting that it might be possible to separate, intact, the individual single-stranded circular half-chromosomes which constitute the double-stranded circular chromosomes of certain plasmids. This would not be possible unless the chromosomes had one of the alternative, topologically non-linked structures. It is widely believed that after a half-century of worldwide DNA research, any significant change to the Watson-Crick structure is unlikely to stand up to scrutiny. Nevertheless, the present author has found that in many instances in which the behavior of circular duplex DNA is considered to be explicable only in terms of the topologically linked helical model, it is also possible to explain that same behavior in terms of a topologically non-linked model. It is necessary, in these instances, to make certain logical assumptions which cannot be conclusively proven at the present time. The author herein offers an example of one such instance, namely an examination of the behavior of circular duplex DNA in an alkaline

  2. Magnetization reversal assisted by half antivortex states in nanostructured circular cobalt disks

    SciTech Connect

    Lara, A.; Aliev, F. G.; Dobrovolskiy, O. V.; Prieto, J. L.; Huth, M.

    2014-11-03

    The half antivortex, a fundamental topological structure which determines magnetization reversal of submicron magnetic devices with domain walls, has been suggested also to play a crucial role in spin torque induced vortex core reversal in circular disks. Here, we report on magnetization reversal in circular disks with nanoholes through consecutive metastable states with half antivortices. In-plane anisotropic magnetoresistance and broadband susceptibility measurements accompanied by micromagnetic simulations reveal that cobalt (Co) disks with two and three linearly arranged nanoholes directed at 45° and 135° with respect to the external magnetic field show reproducible step-like changes in the anisotropic magnetoresistance and magnetic permeability due to transitions between different intermediate states mediated by vortices and half antivortices confined to the dot nanoholes and edges, respectively. Our findings are relevant for the development of multi-hole based spintronic and magnetic memory devices.

  3. Magnetization reversal assisted by half antivortex states in nanostructured circular cobalt disks

    NASA Astrophysics Data System (ADS)

    Lara, A.; Dobrovolskiy, O. V.; Prieto, J. L.; Huth, M.; Aliev, F. G.

    2014-11-01

    The half antivortex, a fundamental topological structure which determines magnetization reversal of submicron magnetic devices with domain walls, has been suggested also to play a crucial role in spin torque induced vortex core reversal in circular disks. Here, we report on magnetization reversal in circular disks with nanoholes through consecutive metastable states with half antivortices. In-plane anisotropic magnetoresistance and broadband susceptibility measurements accompanied by micromagnetic simulations reveal that cobalt (Co) disks with two and three linearly arranged nanoholes directed at 45° and 135° with respect to the external magnetic field show reproducible step-like changes in the anisotropic magnetoresistance and magnetic permeability due to transitions between different intermediate states mediated by vortices and half antivortices confined to the dot nanoholes and edges, respectively. Our findings are relevant for the development of multi-hole based spintronic and magnetic memory devices.

  4. The estimation of material and patch parameters in a PDE-based circular plate model

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Smith, Ralph C.; Brown, D. E.; Metcalf, Vern L.; Silcox, R. J.

    1995-01-01

    The estimation of material and patch parameters for a system involving a circular plate, to which piezoceramic patches are bonded, is considered. A partial differential equation (PDE) model for the thin circular plate is used with the passive and active contributions form the patches included in the internal and external bending moments. This model contains piecewise constant parameters describing the density, flexural rigidity, Poisson ratio, and Kelvin-Voigt damping for the system as well as patch constants and a coefficient for viscous air damping. Examples demonstrating the estimation of these parameters with experimental acceleration data and a variety of inputs to the experimental plate are presented. By using a physically-derived PDE model to describe the system, parameter sets consistent across experiments are obtained, even when phenomena such as damping due to electric circuits affect the system dynamics.

  5. 49 CFR 1544.305 - Security Directives and Information Circulars.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... and Information Circulars. (a) TSA may issue an Information Circular to notify aircraft operators of... with an operational need-to-know. (2) Refuse to release the Security Directive or Information Circular, and information contained in either document, to persons other than those with an operational...

  6. 15 CFR 14.6 - Availability of OMB circulars.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Availability of OMB circulars. 14.6 Section 14.6 Commerce and Foreign Trade Office of the Secretary of Commerce UNIFORM ADMINISTRATIVE... COMMERCIAL ORGANIZATIONS General § 14.6 Availability of OMB circulars. OMB circulars cited in this part...

  7. 49 CFR 1548.19 - Security Directives and Information Circulars.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 9 2011-10-01 2011-10-01 false Security Directives and Information Circulars... CARRIER SECURITY § 1548.19 Security Directives and Information Circulars. (a) TSA may issue an Information Circular to notify indirect air carriers of security concerns. (b) When TSA determines that...

  8. 49 CFR 1549.109 - Security Directives and Information Circulars.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 9 2011-10-01 2011-10-01 false Security Directives and Information Circulars... SCREENING PROGRAM Operations § 1549.109 Security Directives and Information Circulars. (a) TSA may issue an Information Circular to notify certified cargo screening facilities of security concerns. (b) When...

  9. 17 CFR 230.255 - Preliminary Offering Circulars.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Preliminary Offering Circulars... Preliminary Offering Circulars. (a) Prior to qualification of the required offering statement, but after its... front cover page of the material bears the caption “Preliminary Offering Circular,” the date of...

  10. 17 CFR 230.255 - Preliminary Offering Circulars.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Preliminary Offering Circulars... Preliminary Offering Circulars. (a) Prior to qualification of the required offering statement, but after its... front cover page of the material bears the caption “Preliminary Offering Circular,” the date of...

  11. 15 CFR 14.6 - Availability of OMB circulars.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Availability of OMB circulars. 14.6 Section 14.6 Commerce and Foreign Trade Office of the Secretary of Commerce UNIFORM ADMINISTRATIVE... COMMERCIAL ORGANIZATIONS General § 14.6 Availability of OMB circulars. OMB circulars cited in this part...

  12. 49 CFR 1548.19 - Security Directives and Information Circulars.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Security Directives and Information Circulars... CARRIER SECURITY § 1548.19 Security Directives and Information Circulars. (a) TSA may issue an Information Circular to notify indirect air carriers of security concerns. (b) When TSA determines that...

  13. 49 CFR 1549.109 - Security Directives and Information Circulars.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Security Directives and Information Circulars... SCREENING PROGRAM Operations § 1549.109 Security Directives and Information Circulars. (a) TSA may issue an Information Circular to notify certified cargo screening facilities of security concerns. (b) When...

  14. Shock structure in non-circular jets

    NASA Technical Reports Server (NTRS)

    Morris, Philip J.; Bhat, Thonse R. S.

    1989-01-01

    The shock-cell structure of supersonic jets with non-circular exit geometry is modeled using a linearized analysis. The model takes into account the finite thickness of the jet shear layer using realistic velocity and density profiles. The effects of the shear layer turbulence are included by incorporating eddy-viscosity terms. A finite-difference numerical method is used to solve the steady linearized equations of motion. A body-fitted coordinate system is used to describe the shear layer. The variation of the pressure fluctuation with downstream distance is given for circular jets and for an elliptic jet of aspect ratio 2.0. Comparisons with experimental data are made. Difficulties with the numerical technique are also discussed.

  15. Circular polarization sensitive absorbers based on graphene

    NASA Astrophysics Data System (ADS)

    Yang, Kunpeng; Wang, Min; Pu, Mingbo; Wu, Xiaoyu; Gao, Hui; Hu, Chenggang; Luo, Xiangang

    2016-04-01

    It is well known that the polarization of a linearly polarized (LP) light would rotate after passing through a single layer graphene under the bias of a perpendicular magnetostatic field. Here we show that a corresponding phase shift could be expected for circularly polarized (CP) light, which can be engineered to design the circular polarization sensitive devices. We theoretically validate that an ultrathin graphene-based absorber with the thickness about λ/76 can be obtained, which shows efficient absorption >90% within incident angles of ±80°. The angle-independent phase shift produced by the graphene is responsible for the nearly omnidirectional absorber. Furthermore, a broadband absorber in frequencies ranging from 2.343 to 5.885 THz with absorption over 90% is designed by engineering the dispersion of graphene.

  16. Circular RNAs: Novel Regulators of Neuronal Development

    PubMed Central

    van Rossum, Daniëlle; Verheijen, Bert M.; Pasterkamp, R. Jeroen

    2016-01-01

    Circular RNAs (circRNAs) are highly stable, circularized long non-coding RNAs. circRNAs are conserved across species and appear to be specifically enriched in the nervous system. Recent studies show that many circRNAs are expressed in a tissue- and developmental-stage-specific manner, reveal a striking regulation of circRNAs during neuronal development, and detect their presence at synaptic sites. The exact functions of circRNAs remain poorly understood, but evidence from analysis of some circRNA molecules suggests that they could substantially contribute to the regulation of gene expression, particularly in architecturally complex and polarized cells such as neurons. Emerging evidence also indicates that circRNAs are involved in the development and progression of various neurological disorders. In this review, we summarize the molecular characteristics of circRNAs and discuss their proposed functions and mechanism-of-action in developing neurons. PMID:27616979

  17. Circular machine design techniques and tools

    SciTech Connect

    Servranckx, R.V.; Brown, K.L.

    1986-04-01

    Some of the basic optics principles involved in the design of circular accelerators such as Alternating Gradient Synchrotrons, Storage and Collision Rings, and Pulse Stretcher Rings are outlined. Typical problems facing a designer are defined, and the main references and computational tools are reviewed that are presently available. Two particular classes of problems that occur typically in accelerator design are listed - global value problems, which affect the control of parameters which are characteristic of the complete closed circular machine, and local value problems. Basic mathematical formulae are given that are considered useful for a first draft of a design. The basic optics building blocks that can be used to formulate an initial machine design are introduced, giving only the elementary properties and transfer matrices only in one transverse plane. Solutions are presented for some first-order and second-order design problems. (LEW)

  18. Entropic penalties in circular DNA assembly

    NASA Astrophysics Data System (ADS)

    Zoli, Marco

    2014-11-01

    The thermodynamic properties of DNA circular molecules are investigated by a new path integral computational method which treats in the real space the fundamental forces stabilizing the molecule. The base pair and stacking contributions to the classical action are evaluated separately by simulating a broad ensemble of twisted conformations. We obtain, for two short sequences, a free energy landscape with multiple wells corresponding to the most convenient values of helical repeat. Our results point to a intrinsic flexibility of the circular structures in which the base pair fluctuations move the system from one well to the next thus causing the local unwinding of the helix. The latter is more pronounced in the shorter sequence whose cyclization causes a higher bending stress. The entropic reductions associated to the formation of the ordered helicoidal structure are estimated.

  19. Circular polarization sensitive absorbers based on graphene

    PubMed Central

    Yang, Kunpeng; Wang, Min; Pu, Mingbo; Wu, Xiaoyu; Gao, Hui; Hu, Chenggang; Luo, Xiangang

    2016-01-01

    It is well known that the polarization of a linearly polarized (LP) light would rotate after passing through a single layer graphene under the bias of a perpendicular magnetostatic field. Here we show that a corresponding phase shift could be expected for circularly polarized (CP) light, which can be engineered to design the circular polarization sensitive devices. We theoretically validate that an ultrathin graphene-based absorber with the thickness about λ/76 can be obtained, which shows efficient absorption >90% within incident angles of ±80°. The angle-independent phase shift produced by the graphene is responsible for the nearly omnidirectional absorber. Furthermore, a broadband absorber in frequencies ranging from 2.343 to 5.885 THz with absorption over 90% is designed by engineering the dispersion of graphene. PMID:27034257

  20. Circular RNAs: Novel Regulators of Neuronal Development.

    PubMed

    van Rossum, Daniëlle; Verheijen, Bert M; Pasterkamp, R Jeroen

    2016-01-01

    Circular RNAs (circRNAs) are highly stable, circularized long non-coding RNAs. circRNAs are conserved across species and appear to be specifically enriched in the nervous system. Recent studies show that many circRNAs are expressed in a tissue- and developmental-stage-specific manner, reveal a striking regulation of circRNAs during neuronal development, and detect their presence at synaptic sites. The exact functions of circRNAs remain poorly understood, but evidence from analysis of some circRNA molecules suggests that they could substantially contribute to the regulation of gene expression, particularly in architecturally complex and polarized cells such as neurons. Emerging evidence also indicates that circRNAs are involved in the development and progression of various neurological disorders. In this review, we summarize the molecular characteristics of circRNAs and discuss their proposed functions and mechanism-of-action in developing neurons. PMID:27616979

  1. Circular, confined distribution for charged particle beams

    DOEpatents

    Garnett, Robert W.; Dobelbower, M. Christian

    1995-01-01

    A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location.

  2. Circular, confined distribution for charged particle beams

    DOEpatents

    Garnett, R.W.; Dobelbower, M.C.

    1995-11-21

    A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location. 26 figs.

  3. Entropic penalties in circular DNA assembly.

    PubMed

    Zoli, Marco

    2014-11-01

    The thermodynamic properties of DNA circular molecules are investigated by a new path integral computational method which treats in the real space the fundamental forces stabilizing the molecule. The base pair and stacking contributions to the classical action are evaluated separately by simulating a broad ensemble of twisted conformations. We obtain, for two short sequences, a free energy landscape with multiple wells corresponding to the most convenient values of helical repeat. Our results point to a intrinsic flexibility of the circular structures in which the base pair fluctuations move the system from one well to the next thus causing the local unwinding of the helix. The latter is more pronounced in the shorter sequence whose cyclization causes a higher bending stress. The entropic reductions associated to the formation of the ordered helicoidal structure are estimated. PMID:25381507

  4. Entropic penalties in circular DNA assembly

    SciTech Connect

    Zoli, Marco

    2014-11-07

    The thermodynamic properties of DNA circular molecules are investigated by a new path integral computational method which treats in the real space the fundamental forces stabilizing the molecule. The base pair and stacking contributions to the classical action are evaluated separately by simulating a broad ensemble of twisted conformations. We obtain, for two short sequences, a free energy landscape with multiple wells corresponding to the most convenient values of helical repeat. Our results point to a intrinsic flexibility of the circular structures in which the base pair fluctuations move the system from one well to the next thus causing the local unwinding of the helix. The latter is more pronounced in the shorter sequence whose cyclization causes a higher bending stress. The entropic reductions associated to the formation of the ordered helicoidal structure are estimated.

  5. Impedance properties of circular microstrip antenna

    NASA Technical Reports Server (NTRS)

    Deshpande, M. D.; Bailey, M. C.

    1983-01-01

    A moment method solution to the input impedance of a circular microstrip antenna excited by either a microstrip feed or a coaxial probe is presented. Using the exact dyadic Green's function and the Fourier transform the problem is formulated in terms of Richmond's reaction integral equation from which the unknown patch current can be solved for. The patch current is expanded in terms of regular surface patch modes and an attachment mode (for probe excited case) which insures continuity of the current at probe/patch junction, proper polarization and p-dependance of patch current in the vicinity of the probe. The input impedance of a circular microstrip antenna is computed and compared with earlier results. Effect of attachment mode on the input impedance is also discussed.

  6. Safety Analysis Using Lebesgue Strain Measure of Thick-Walled Cylinder for Functionally Graded Material under Internal and External Pressure

    PubMed Central

    Aggarwal, A. K.; Sharma, Richa; Sharma, Sanjeev

    2013-01-01

    Safety analysis has been done for thick-walled circular cylinder under internal and external pressure using transition theory which is based on the concept of generalized principal Lebesgue strain measure. Results have been analyzed theoretically and discussed numerically. From the analysis, it can be concluded that circular cylinder made of functionally graded material is on the safer side of the design as compared to homogeneous cylinder with internal and external pressure, which leads to the idea of “stress saving” that minimizes the possibility of fracture of cylinder. PMID:24089605

  7. Circular analysis in complex stochastic systems

    NASA Astrophysics Data System (ADS)

    Valleriani, Angelo

    2015-12-01

    Ruling out observations can lead to wrong models. This danger occurs unwillingly when one selects observations, experiments, simulations or time-series based on their outcome. In stochastic processes, conditioning on the future outcome biases all local transition probabilities and makes them consistent with the selected outcome. This circular self-consistency leads to models that are inconsistent with physical reality. It is also the reason why models built solely on macroscopic observations are prone to this fallacy.

  8. Calculating the CEP (Circular Error Probable)

    NASA Technical Reports Server (NTRS)

    1987-01-01

    This report compares the probability contained in the Circular Error Probable associated with an Elliptical Error Probable to that of the EEP at a given confidence level. The levels examined are 50 percent and 95 percent. The CEP is found to be both more conservative and less conservative than the associated EEP, depending on the eccentricity of the ellipse. The formulas used are derived in the appendix.

  9. Roles of Circular RNAs in Neurologic Disease

    PubMed Central

    Shao, Yiye; Chen, Yinghui

    2016-01-01

    Circular RNAs (circRNAs) are a novel type of endogenous noncoding RNA receiving increasing attention. They have been shown to act as a natural microRNA sponges that repress the activity of corresponding miRNAs by binding with them, thus regulating target genes. Numerous studies have shown that miRNAs are involved in the pathogenesis of neurological diseases. Therefore, circRNAs may act as important regulatory factors in the occurrence and development processes of neurological disease. PMID:27147959

  10. A fractal circular polarized RFID tag antenna

    NASA Astrophysics Data System (ADS)

    Chaouki, Guesmi; Ferchichi, Abdelhak; Gharsallah, Ali

    2013-09-01

    In this paper, we present a novel fractal antenna for radiofrequency identification (RFID) tags. The proposed antenna has a resonant frequency equal to 2.45GHz and circular polarization. The fractal technique was very useful to obtain a miniaturization of antenna size by more than 30%. The gain and directivity of the antenna are acceptable for the desired RFID application. All the results are obtained using CST Microwave simulation tool.

  11. Circular dichroism of planar chiral magnetic metamaterials.

    PubMed

    Decker, M; Klein, M W; Wegener, M; Linden, S

    2007-04-01

    We propose, fabricate, and study a double-layer chiral planar metamaterial that exhibits pronounced circular dichroism at near-infrared wavelengths. The antisymmetric oscillation modes of the two coupled layers allow local magnetic-dipole moments and enhanced polarization effects compared with similar single-layer systems where only electric-dipole moments occur. Experiment and rigorous theoretical calculations are in good agreement. PMID:17339960

  12. Accelerator considerations of large circular colliders

    NASA Astrophysics Data System (ADS)

    Chao, Alex

    2016-07-01

    As we consider the tremendous physics reaches of the big future circular electron-positron and proton-proton colliders, it might be advisable to keep a close track of what accelerator challenges they face. Good progresses are being made, and yet it is reported here that substantial investments in funding, manpower, as well as a long sustained time to the R&D efforts will be required in preparation to realize these dream colliders.

  13. Circular analysis in complex stochastic systems

    PubMed Central

    Valleriani, Angelo

    2015-01-01

    Ruling out observations can lead to wrong models. This danger occurs unwillingly when one selects observations, experiments, simulations or time-series based on their outcome. In stochastic processes, conditioning on the future outcome biases all local transition probabilities and makes them consistent with the selected outcome. This circular self-consistency leads to models that are inconsistent with physical reality. It is also the reason why models built solely on macroscopic observations are prone to this fallacy. PMID:26656656

  14. Circular zig-zag scan video format

    DOEpatents

    Peterson, C. Glen; Simmons, Charles M.

    1992-01-01

    A circular, ziz-zag scan for use with vidicon tubes. A sine wave is generated, rectified and its fourth root extracted. The fourth root, and its inverse, are used to generate horizontal ramp and sync signals. The fourth root is also used to generate a vertical sync signal, and the vertical sync signal, along with the horizontal sync signal, are used to generate the vertical ramp signal. Cathode blanking and preamplifier clamp signals are also obtained from the vertical sync signal.

  15. Circular Intensity Differential Scattering of chiral molecules

    SciTech Connect

    Bustamante, C.J.

    1980-12-01

    In this thesis a theory of the Circular Intensity Differential Scattering (CIDS) of chiral molecules as modelled by a helix oriented with respect to the direction of incidence of light is presented. It is shown that a necessary condition for the existence of CIDS is the presence of an asymmetric polarizability in the scatterer. The polarizability of the scatterer is assumed generally complex, so that both refractive and absorptive phenomena are taken into account.

  16. Pulsed Accretion onto Eccentric and Circular Binaries

    NASA Astrophysics Data System (ADS)

    Muñoz, Diego J.; Lai, Dong

    2016-08-01

    We present numerical simulations of circumbinary accretion onto eccentric and circular binaries using the moving-mesh code AREPO. This is the first set of simulations to tackle the problem of binary accretion using a finite-volume scheme on a freely moving mesh, which allows for accurate measurements of accretion onto individual stars for arbitrary binary eccentricity. While accretion onto a circular binary shows bursts with period of ˜ 5 times the binary period P b, accretion onto an eccentric binary is predominantly modulated at the period ˜ 1{P}{{b}}. For an equal-mass circular binary, the accretion rates onto individual stars are quite similar to each other, following the same variable pattern in time. By contrast, for eccentric binaries, one of the stars can accrete at a rate 10–20 times larger than its companion. This “symmetry breaking” between the stars, however, alternates over timescales of order 200P b and can be attributed to a slowly precessing, eccentric circumbinary disk. Over longer timescales, the net accretion rates onto individual stars are the same, reaching a quasi-steady state with the circumbinary disk. These results have important implications for the accretion behavior of binary T Tauri stars and supermassive binary black holes.

  17. Pulsed Accretion onto Eccentric and Circular Binaries

    NASA Astrophysics Data System (ADS)

    Muñoz, Diego J.; Lai, Dong

    2016-08-01

    We present numerical simulations of circumbinary accretion onto eccentric and circular binaries using the moving-mesh code AREPO. This is the first set of simulations to tackle the problem of binary accretion using a finite-volume scheme on a freely moving mesh, which allows for accurate measurements of accretion onto individual stars for arbitrary binary eccentricity. While accretion onto a circular binary shows bursts with period of ∼ 5 times the binary period P b, accretion onto an eccentric binary is predominantly modulated at the period ∼ 1{P}{{b}}. For an equal-mass circular binary, the accretion rates onto individual stars are quite similar to each other, following the same variable pattern in time. By contrast, for eccentric binaries, one of the stars can accrete at a rate 10–20 times larger than its companion. This “symmetry breaking” between the stars, however, alternates over timescales of order 200P b and can be attributed to a slowly precessing, eccentric circumbinary disk. Over longer timescales, the net accretion rates onto individual stars are the same, reaching a quasi-steady state with the circumbinary disk. These results have important implications for the accretion behavior of binary T Tauri stars and supermassive binary black holes.

  18. Online inspection of circular fluorescent lamp

    NASA Astrophysics Data System (ADS)

    Ang, Beng-Hoe

    1998-10-01

    One step in the manufacture of circular fluorescent lamps is the mercury (Hg) injection process in which a small amount of mercury approximately 20 mg is injected into the fluorescent tube. An on-line detection of mercury is required to ensure that the amount of mercury residual inside the tube is within the acceptable tolerance. This critical operation is to reduce manufacturing overhead by controlling cost and reducing waste of materials. In view of this, an attempt has been made to design and develop an on- line mercury detection system with important benefits to the manufacturers, such as increased throughput, accuracy, reliability and consistency. This paper presents the configuration and development works of the on-line circular fluorescent lamp inspection system developed by Industrial Project Group--Machine Vision Center of Nanyang Polytechnic. The inspection system performs on-line detection of mercury particles (Hg) inside the circular fluorescent lamp. Taking the orientation and translation offsets of the lamp into consideration, it detects the presence/absence as well as the size of the injected mercury. The system has been successfully operating 15 hours per day and inspecting more than 22 thousands lamps in the production plant.

  19. Continuous-wave circular polarization terahertz imaging

    NASA Astrophysics Data System (ADS)

    Martin, Jillian P.; Joseph, Cecil S.; Giles, Robert H.

    2016-07-01

    Biomedical applications of terahertz (THz) radiation are appealing because THz radiation is nonionizing and has the demonstrated ability to detect intrinsic contrasts between cancerous and normal tissue. A linear polarization-sensitive detection technique for tumor margin delineation has already been demonstrated; however, utilization of a circular polarization-sensitive detection technique has yet to be explored at THz frequencies. A reflective, continuous-wave THz imaging system capable of illuminating a target sample at 584 GHz with either linearly or circularly polarized radiation, and capable of collecting both cross- and copolarized signals remitted from the target, is implemented. To demonstrate the system's utility, a fresh ex vivo human skin tissue specimen containing nonmelanoma skin cancer was imaged. Both polarization-sensitive detection techniques showed contrast between tumor and normal skin tissue, although some differences in images were observed between the two techniques. Our results indicate that further investigation is required to explain the contrast mechanism, as well as to quantify the specificity and sensitivity of the circular polarization-sensitive detection technique.

  20. Navigation and vessel inspection circular No. 0-97. Index of Navigation and Vessel Inspection Circulars (NVICS). Final report

    SciTech Connect

    1996-11-21

    This Circular provides the current listing of Navigation and Vessel Inspection Circulars (NVICS). NVICs are issued by Coast Guard Headquarters in the form of duplicated circulars. Their purpose is to inform the public of Coast Guard guidance, requirements or information regarding marine safety activities.

  1. Hanford External Dosimetry Program

    SciTech Connect

    Fix, J.J.

    1990-10-01

    This document describes the Hanford External Dosimetry Program as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy (DOE) and its Hanford contractors. Program services include administrating the Hanford personnel dosimeter processing program and ensuring that the related dosimeter data accurately reflect occupational dose received by Hanford personnel or visitors. Specific chapters of this report deal with the following subjects: personnel dosimetry organizations at Hanford and the associated DOE and contractor exposure guidelines; types, characteristics, and procurement of personnel dosimeters used at Hanford; personnel dosimeter identification, acceptance testing, accountability, and exchange; dosimeter processing and data recording practices; standard sources, calibration factors, and calibration processes (including algorithms) used for calibrating Hanford personnel dosimeters; system operating parameters required for assurance of dosimeter processing quality control; special dose evaluation methods applied for individuals under abnormal circumstances (i.e., lost results, etc.); and methods for evaluating personnel doses from nuclear accidents. 1 ref., 14 figs., 5 tabs.

  2. External Measures of Cognition

    PubMed Central

    Cairό, Osvaldo

    2011-01-01

    The human brain is undoubtedly the most impressive, complex, and intricate organ that has evolved over time. It is also probably the least understood, and for that reason, the one that is currently attracting the most attention. In fact, the number of comparative analyses that focus on the evolution of brain size in Homo sapiens and other species has increased dramatically in recent years. In neuroscience, no other issue has generated so much interest and been the topic of so many heated debates as the difference in brain size between socially defined population groups, both its connotations and implications. For over a century, external measures of cognition have been related to intelligence. However, it is still unclear whether these measures actually correspond to cognitive abilities. In summary, this paper must be reviewed with this premise in mind. PMID:22065955

  3. [External ophthalmomyiasis: case reports].

    PubMed

    Yar, Kemal; Özcan, Altan Atakan; Koltaş, İ Soner

    2011-01-01

    We report two cases with external ophthalmomyiasis due to infestation with the larvae of Oestrus ovis. During an ophthalmologic examination, motile larvae were seen on the conjunctiva, which were removed and sent to the Department of Parasitology for identification. Microscopic examination of the specimens revealed that both patients were infested with the first stage larvae of O. ovis. The patients were treated with topical antibiotics and steroids and recovered without any complications. O. ovis larvae are the most common cause of ophthalmomyiasis worldwide. They are usually seen in underdeveloped, agricultural areas with high numbers of livestock, especially during Spring and Summer. These kind of infestations should be kept in mind in cases of conjunctivitis in the warm months of the year. PMID:22198925

  4. Higher order vortex gyrotropic modes in circular ferromagnetic nanodots.

    PubMed

    Ding, Junjia; Kakazei, Gleb N; Liu, Xinming; Guslienko, Konstantin Y; Adeyeye, Adekunle O

    2014-01-01

    Magnetic vortex that consists of an in-plane curling magnetization configuration and a needle-like core region with out-of-plane magnetization is known to be the ground state of geometrically confined submicron soft magnetic elements. Here magnetodynamics of relatively thick (50-100 nm) circular Ni80Fe20 dots were probed by broadband ferromagnetic resonance in the absence of external magnetic field. Spin excitation modes related to the thickness dependent vortex core gyrotropic dynamics were detected experimentally in the gigahertz frequency range. Both analytical theory and micromagnetic simulations revealed that these exchange dominated modes are flexure oscillations of the vortex core string with n = 0,1,2 nodes along the dot thickness. The intensity of the mode with n = 1 depends significantly on both dot thickness and diameter and in some cases is higher than the one of the uniform mode with n = 0. This opens promising perspectives in the area of spin transfer torque oscillators. PMID:24762659

  5. Oscillating laminar electrokinetic flow in infinitely extended circular microchannels.

    PubMed

    Bhattacharyya, A; Masliyah, J H; Yang, J

    2003-05-01

    This article addresses the problem of oscillating laminar electrokinetic liquid flow in an infinitely extended circular microchannel. Based on the Debye-Huckel approximation for low surface potential at the channel wall, a complex variable approach is used to obtain an analytical solution for the flow. The complex counterparts of the flow rate and the current are linearly dependent on the pressure gradient and the external electric field. This property is used to show that Onsager's principle of reciprocity continues to be valid (involving the complex quantities) for the stated problem. During oscillating pressure-driven flow, the electroviscous effect for a given value of the normalized reciprocal electrical double-layer (EDL) thickness is observed to attain a maximum at a certain normalized frequency. In general, an increasing normalized frequency results in a reduction of EDL effects, leading to (i). a volumetric flow rate in the case of streaming potential approaching that predicted by the theory without EDL effects, and (ii). a reduction in the volumetric flow rate in the case of electroosmosis. PMID:12725819

  6. Circular RNAs as Promising Biomarkers: A Mini-Review.

    PubMed

    Abu, Nadiah; Jamal, Rahman

    2016-01-01

    The interest in circular RNAs has resurfaced in the past few years. What was considered as "junk" for nearly two decades is now one of the most interesting molecules. Circular RNAs are non-coding RNAs that are formed by back-splicing events and have covalently closed loops with no poly-adenylated tails. The regulation of circular RNAs is distinctive and they are selectively abundant in different types of tissues. Based on the current knowledge of circular RNAs, these molecules have the potential to be the "next big thing" especially as biomarkers for different diseases. This mini-review attempts to concisely look at the biology of circular RNAs, the putative functional activities, the prevalence of circular RNAs, and the possible role of circular RNA as biomarkers for diagnosis or measuring drug response. PMID:27588005

  7. Circular RNAs as Promising Biomarkers: A Mini-Review

    PubMed Central

    Abu, Nadiah; Jamal, Rahman

    2016-01-01

    The interest in circular RNAs has resurfaced in the past few years. What was considered as “junk” for nearly two decades is now one of the most interesting molecules. Circular RNAs are non-coding RNAs that are formed by back-splicing events and have covalently closed loops with no poly-adenylated tails. The regulation of circular RNAs is distinctive and they are selectively abundant in different types of tissues. Based on the current knowledge of circular RNAs, these molecules have the potential to be the “next big thing” especially as biomarkers for different diseases. This mini-review attempts to concisely look at the biology of circular RNAs, the putative functional activities, the prevalence of circular RNAs, and the possible role of circular RNA as biomarkers for diagnosis or measuring drug response. PMID:27588005

  8. Cloaking from surface plasmon polaritons by a circular array of point scatterers.

    PubMed

    Baumeier, Björn; Leskova, Tamara A; Maradudin, Alexei A

    2009-12-11

    In recent years it has been demonstrated both theoretically and experimentally that it is possible to cloak a predefined region of space from interaction with external volume electromagnetic waves, rendering an arbitrary object inside this region invisible to an outside observer. The several strategies that have been developed for achieving such cloaking cannot be applied directly to the cloaking of a surface feature from surface plasmon polaritons propagating on that surface. Here we demonstrate that it is possible to generate an arrangement of two concentric rings of point scatterers on a metal surface that significantly reduces the scattering of surface plasmon polaritons from an object enclosed within this circular structure. PMID:20366219

  9. Circularly polarized wave propagation in magnetofluid dynamics for relativistic electron-positron plasmas

    NASA Astrophysics Data System (ADS)

    Asenjo, Felipe A.; Muñoz, Víctor; Valdivia, Juan Alejandro; Hada, Tohru

    2009-12-01

    The dispersion relation for circularly polarized electromagnetic waves propagating in the direction of an external magnetic field in a relativistic electron-positron plasma with arbitrary constant drift velocities is obtained for constant temperature in the homentropic regime. This result is an exact solution of the nonlinear magnetofluid unification field formalism introduced by S. Mahajan [Phys. Rev. Lett. 90, 035001 (2003)], where the electromagnetic and fluid fields are coupled through the relativistic enthalpy density. The behavior of electromagnetic and Alfvén branches of the dispersion relation are discussed for different temperatures.

  10. Computational simulations of hydrogen circular migration in protonated acetylene induced by circularly polarized light.

    PubMed

    Shi, Xuetao; Li, Wen; Schlegel, H Bernhard

    2016-08-28

    The hydrogens in protonated acetylene are very mobile and can easily migrate around the C2 core by moving between classical and non-classical structures of the cation. The lowest energy structure is the T-shaped, non-classical cation with a hydrogen bridging the two carbons. Conversion to the classical H2CCH(+) ion requires only 4 kcal/mol. The effect of circularly polarized light on the migration of hydrogens in oriented C2H3 (+) has been simulated by Born-Oppenheimer molecular dynamics. Classical trajectory calculations were carried out with the M062X/6-311+G(3df,2pd) level of theory using linearly and circularly polarized 32 cycle 7 μm cosine squared pulses with peak intensity of 5.6 × 10(13) W/cm(2) and 3.15 × 10(13) W/cm(2), respectively. These linearly and circularly polarized pulses transfer similar amounts of energy and total angular momentum to C2H3 (+). The average angular momentum vectors of the three hydrogens show opposite directions of rotation for right and left circularly polarized light, but no directional preference for linearly polarized light. This difference results in an appreciable amount of angular displacement of the three hydrogens relative to the C2 core for circularly polarized light, but only an insignificant amount for linearly polarized light. Over the course of the simulation with circularly polarized light, this corresponds to a propeller-like motion of the three hydrogens around the C2 core of protonated acetylene. PMID:27586924

  11. [Haikou issues circular on planned parenthood].

    PubMed

    1981-02-01

    The Organization Department of the Haikou Municipal CCP Committee, the municipal grain, finance, commerce, education bureau, personnel, public security, labor, civil affairs, public health, and housing bureaus, supply and marketing cooperative, and planned parenthood office recently issued a joint circular on implementing the provincial planned parenthood regulations. The circular demanded that the marriage registration and census system be seriously implemented. When people are registering for marriage, we must teach them to have only 1 child. We must give priority in housing and employment to an only child and his parents. When commercial, supply, and marketing departments are distributing coupons for fuel, and nonstaple food, they should supply a double amount to the only child. We must carry out serious health care for an only child and give them regular physical check-ups. When they are ill, hospitals should give them priority in registration, treatment, reservation of beds and medicines. The circular reiterated: We must seriously implement the stipulations on rewards and punishments contained in the provincial planned parenthood regulations. Cadres, staff, or workers who apply to have only 1 child must be given lump sums in addition to enjoying the relevant rewards stipulated by the regulations. Cadres, staff, workers, inhabitants, and commune workers who depend on state grain who violate the regulations must be punished according to the regulation. As for those who have 3 or more than 3 children, a 2nd child without planning, or an illegitimate child, the child's grain ration will be sold at negotiated price up to the age of 14. The grain department will distribute to them a supply ticket for negotiated price grain to buy grain in assigned grain shops. PMID:12338059

  12. Circular orbits on a warped spandex fabric

    NASA Astrophysics Data System (ADS)

    Middleton, Chad A.; Langston, Michael

    2014-04-01

    We present a theoretical and experimental analysis of circular-like orbits made by a marble rolling on a warped spandex fabric. We show that the mass of the fabric interior to the orbital path influences the motion of the marble in a nontrivial way and can even dominate the orbital characteristics. We also compare a Kepler-like expression for such orbits to similar expressions for orbits about a spherically symmetric massive object in the presence of a constant vacuum energy, as described by general relativity.

  13. Vortex motion behind a circular cylinder

    NASA Technical Reports Server (NTRS)

    Foeppl, L.

    1983-01-01

    Vortex motion behind a circular cylinder moving through water is discussed. It is shown that a pair of vortices form behind a moving cylinder and that their centers will move along a predictable curve. This curve represents an equilibrium condition which, however, is subject to perturbation. The stability of the vortex pair is investigated. Movement of the vortex pair away from the cylinder is calculated as an explanation of the resistance of the cylinder. Finally, the principles elaborated are applied to the flow around a flat plate.

  14. Optofluidic circular grating distributed feedback dye laser

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Li, Zhenyu; Henry, M. David; Scherer, Axel

    2009-07-01

    We demonstrate an optically pumped surface emitting optofluidic dye laser using a second-order circular grating distributed feedback resonator. We present a composite bilayer soft lithography technique specifically developed for the fabrication of our dye laser and investigate a hybrid polymer material system [poly(dimethylsiloxane)/perfluoropolyether] to construct high-resolution Bragg gratings. Our lasers emit single frequency light at low lasing thresholds of 6 μJ/mm2. These optofluidic dye lasers can serve as low-cost and compact coherent light sources that are fully integrated within microfluidic analysis chips and provide an efficient approach to construct compact spectroscopy systems.

  15. [Anesthetic maintenance during circular face lifting].

    PubMed

    Parshin, V I; Pastukhova, N K

    2010-01-01

    The paper deals with the specific features of anesthetic maintenance (ketamine, diprivan, dormicum, perfalgan, promedol) during circular face lifting without artificial ventilation. All intravenous anesthesia procedures have yielded good results. Narcotic analgesics may be removed from the anesthetic maintenance scheme, ruling out the necessity of their licensing, storing, and recording. The use of perfalgan causes no hallucinogenic reactions and offers the optimum level of anesthesia. During face lifting, 2.3 +/- 0.6-hour anesthesia with spontaneous breathing is possible, safe, and warranted. PMID:20524331

  16. Acceleration of polarized protons in circular accelerators

    SciTech Connect

    Courant, E.D.; Ruth, R.D.

    1980-09-12

    The theory of depolarization in circular accelerators is presented. The spin equation is first expressed in terms of the particle orbit and then converted to the equivalent spinor equation. The spinor equation is then solved for three different situations: (1) a beam on a flat top near a resonance, (2) uniform acceleration through an isolated resonance, and (3) a model of a fast resonance jump. Finally, the depolarization coefficient, epsilon, is calculated in terms of properties of the particle orbit and the results are applied to a calculation of depolarization in the AGS.

  17. Build a circularly polarized waveguide slot antenna

    NASA Astrophysics Data System (ADS)

    Kisliuk, M.; Axelrod, A.

    1987-06-01

    The development and design of a circularly polarized waveguide slot antenna are described. Consideration is given to the resonance frequency, radiation efficiencies, excitement, and resonant conductance of the transverse and longitudinal slots. The transverse and longitudinal slots in a rectangular guide are analyzed. The voltage distribution across the slot is calculated from the solution of a standard transmission line equation; and using the Poynting theorem the fields scattered by the slot in an arbitrary frequency range are determined. The proposed antenna is examined using an equivalent circuit; a diagram of the circuit is given. The radiation, slot, and antenna efficiencies are measured.

  18. Circular zig-zag scan video format

    DOEpatents

    Peterson, C.G.; Simmons, C.M.

    1992-06-09

    A circular, ziz-zag scan for use with vidicon tubes is disclosed. A sine wave is generated, rectified and its fourth root extracted. The fourth root, and its inverse, are used to generate horizontal ramp and sync signals. The fourth root is also used to generate a vertical sync signal, and the vertical sync signal, along with the horizontal sync signal, are used to generate the vertical ramp signal. Cathode blanking and preamplifier clamp signals are also obtained from the vertical sync signal. 10 figs.

  19. Free boundary, high beta equilibrium in a large aspect ratio tokamak with nearly circular plasma boundary

    SciTech Connect

    Qin, H.; Reiman, A.

    1996-09-25

    An analytic solution is obtained for free-boundary, high-beta equilibria in large aspect ratio tokamaks with a nearly circular plasma boundary. In the absence of surface currents at the plasma-vacuum interface, the free-boundary equilibrium solution introduces constraints arising from the need to couple to an external vacuum field which is physically realizable with a reasonable set of external field coils. This places a strong constraint on the pressure profiles that are consistent with a given boundary shape at high {epsilon}{beta}{sub p}. The equilibrium solution also provides information on the flux surface topology. The plasma is bounded by a separatrix. Increasing the plasma pressure at fixed total current causes the plasma aperture to decrease in a manner that is described.

  20. Competition of circularly polarized laser modes in the modulation instability of hot magnetoplasma

    SciTech Connect

    Sepehri Javan, N.

    2013-01-15

    The present study is aimed to investigate the problem of modulation instability of an intense laser beam in the hot magnetized plasma. The propagation of intense circularly polarized laser beam along the external magnetic field is considered using a relativistic fluid model. The nonlinear equation describing the interaction of laser pulse with magnetized hot plasma is derived in the quasi-neutral approximation, which is valid for hot plasma. Nonlinear dispersion equation for hot plasma is obtained. For left- and right-hand polarizations, the growth rate of instability is achieved and the effect of temperature, external magnetic field, and kind of polarization on the growth rate is considered. It is observed that for the right-hand polarization, increase of magnetic field leads to the increasing of growth rate. Also for the left-hand polarization, increase of magnetic field inversely causes decrease of the growth rate.

  1. Externalities of oil imports revisited

    SciTech Connect

    Lemon, R.

    1980-09-01

    A re-analysis of the externalities associated with oil imports reaffirms the major findings of an earlier study: (1) The current externalities of oil imports are large even after several favorable assumptions are made, including the existence of a large buffer stock and enlightened monetary and fiscal policy. (2) The large externalities of oil imports call for increased domestic supplies, including conservation, if they are cost-effective and based on marginal social costs. (3) A corrective public policy could involve oil-import taxes and the subsidization of new domestic energy sources without large government externalities. 20 references.

  2. External combustor for gas turbine engine

    DOEpatents

    Santanam, Chandran B.; Thomas, William H.; DeJulio, Emil R.

    1991-01-01

    An external combustor for a gas turbine engine has a cyclonic combustion chamber into which combustible gas with entrained solids is introduced through an inlet port in a primary spiral swirl. A metal draft sleeve for conducting a hot gas discharge stream from the cyclonic combustion chamber is mounted on a circular end wall of the latter adjacent the combustible gas inlet. The draft sleeve is mounted concentrically in a cylindrical passage and cooperates with the passage in defining an annulus around the draft sleeve which is open to the cyclonic combustion chamber and which is connected to a source of secondary air. Secondary air issues from the annulus into the cyclonic combustion chamber at a velocity of three to five times the velocity of the combustible gas at the inlet port. The secondary air defines a hollow cylindrical extension of the draft sleeve and persists in the cyclonic combustion chamber a distance of about three to five times the diameter of the draft sleeve. The hollow cylindrical extension shields the drive sleeve from the inlet port to prevent discharge of combustible gas through the draft sleeve.

  3. Simple Broadband Circular Polarizer in Oversized Waveguide

    NASA Astrophysics Data System (ADS)

    Stange, Torsten

    2016-02-01

    In this paper, a possibility is shown to realize a simple waveguide polarizer producing nearly the same circular polarization over a broad frequency range up to an octave. It is based upon the combination of two smoothly squeezed oversized waveguides with different diameters. The principle is similar to an achromatic lens in optics, where two counteracting lenses with differently sloped wavelength dependencies of the refractive index are combined to compensate the dispersion in the desired wavelength range. Consequently, two different wavelengths of light are brought into focus at the same plane. A waveguide for the transmission of microwaves has a similar frequency dependence of the refractive index resulting in a frequency-dependent phase shift between two propagating waves polarized along the symmetry axes of a waveguide with an elliptical cross section. For this reason, an incident wave with a linear polarization between the axes of symmetry can be only converted into a circularly polarized wave over a limited frequency range. However, the diameter and the shape along two counteracting squeezed waveguides can be adjusted in such a way that the frequency dependence of the resultant phase shift is finally canceled out.

  4. High Performance Circularly Polarized Microstrip Antenna

    NASA Technical Reports Server (NTRS)

    Bondyopadhyay, Probir K. (Inventor)

    1997-01-01

    A microstrip antenna for radiating circularly polarized electromagnetic waves comprising a cluster array of at least four microstrip radiator elements, each of which is provided with dual orthogonal coplanar feeds in phase quadrature relation achieved by connection to an asymmetric T-junction power divider impedance notched at resonance. The dual fed circularly polarized reference element is positioned with its axis at a 45 deg angle with respect to the unit cell axis. The other three dual fed elements in the unit cell are positioned and fed with a coplanar feed structure with sequential rotation and phasing to enhance the axial ratio and impedance matching performance over a wide bandwidth. The centers of the radiator elements are disposed at the corners of a square with each side of a length d in the range of 0.7 to 0.9 times the free space wavelength of the antenna radiation and the radiator elements reside in a square unit cell area of sides equal to 2d and thereby permit the array to be used as a phased array antenna for electronic scanning and is realizable in a high temperature superconducting thin film material for high efficiency.

  5. CWG - MUTUAL COUPLING PROGRAM FOR CIRCULAR WAVEGUIDE-FED APERTURE ARRAY (VAX VMS VERSION)

    NASA Technical Reports Server (NTRS)

    Bailey, M. C.

    1994-01-01

    Mutual Coupling Program for Circular Waveguide-fed Aperture Array (CWG) was developed to calculate the electromagnetic interaction between elements of an antenna array of circular apertures with specified aperture field distributions. The field distributions were assumed to be a superposition of the modes which could exist in a circular waveguide. Various external media were included to provide flexibility of use, for example, the flexibility to determine the effects of dielectric covers (i.e., thermal protection system tiles) upon the impedance of aperture type antennas. The impedance and radiation characteristics of planar array antennas depend upon the mutual interaction between all the elements of the array. These interactions are influenced by several parameters (e.g., the array grid geometry, the geometry and excitation of each array element, the medium outside the array, and the internal network feeding the array.) For the class of array antenna whose radiating elements consist of small holes in a flat conducting plate, the electromagnetic problem can be divided into two parts, the internal and the external. In solving the external problem for an array of circular apertures, CWG will compute the mutual interaction between various combinations of circular modal distributions and apertures. CWG computes the mutual coupling between various modes assumed to exist in circular apertures that are located in a flat conducting plane of infinite dimensions. The apertures can radiate into free space, a homogeneous medium, a multilayered region or a reflecting surface. These apertures are assumed to be excited by one or more modes corresponding to the modal distributions in circular waveguides of the same cross sections as the apertures. The apertures may be of different sizes and also of different polarizations. However, the program assumes that each aperture field contains the same modal distributions, and calculates the complex scattering matrix between all mode and

  6. CWG - MUTUAL COUPLING PROGRAM FOR CIRCULAR WAVEGUIDE-FED APERTURE ARRAY (IBM PC VERSION)

    NASA Technical Reports Server (NTRS)

    Bailey, M. C.

    1994-01-01

    Mutual Coupling Program for Circular Waveguide-fed Aperture Array (CWG) was developed to calculate the electromagnetic interaction between elements of an antenna array of circular apertures with specified aperture field distributions. The field distributions were assumed to be a superposition of the modes which could exist in a circular waveguide. Various external media were included to provide flexibility of use, for example, the flexibility to determine the effects of dielectric covers (i.e., thermal protection system tiles) upon the impedance of aperture type antennas. The impedance and radiation characteristics of planar array antennas depend upon the mutual interaction between all the elements of the array. These interactions are influenced by several parameters (e.g., the array grid geometry, the geometry and excitation of each array element, the medium outside the array, and the internal network feeding the array.) For the class of array antenna whose radiating elements consist of small holes in a flat conducting plate, the electromagnetic problem can be divided into two parts, the internal and the external. In solving the external problem for an array of circular apertures, CWG will compute the mutual interaction between various combinations of circular modal distributions and apertures. CWG computes the mutual coupling between various modes assumed to exist in circular apertures that are located in a flat conducting plane of infinite dimensions. The apertures can radiate into free space, a homogeneous medium, a multilayered region or a reflecting surface. These apertures are assumed to be excited by one or more modes corresponding to the modal distributions in circular waveguides of the same cross sections as the apertures. The apertures may be of different sizes and also of different polarizations. However, the program assumes that each aperture field contains the same modal distributions, and calculates the complex scattering matrix between all mode and

  7. Control of Magnetic States of Cobalt Nanorings by an External Azimuthal Field

    NASA Astrophysics Data System (ADS)

    Pradhan, Nihar; Yang, Tianyu; Licht, Abbey; Li, Yihan; Tuominen, Mark; Aidala, Katherine

    2011-03-01

    Ferromagnetic nanorings attract interest due to their potential application in high density data storage and Magnetoresistive Random Access Memory (MRAM) devices. These nanorings show multidomain stable states that need to be well controlled by external in-plane or circular magnetic fields. This talk presents a new method to generate circular magnetic fields to control the magnetic states in different geometries of Cobalt nanoring structures, of varying diameter, width and thickness. A solid platinum AFM tip was used to pass current through a single nanoring, generating a circular magnetic field. In applying this field we were able to change the state of the individual ring without affecting the states of other neighboring rings. The evolution of the magnetic states of individual symmetric and asymmetric Cobalt nanorings with applied azimuthal field will be presented. The work was supported by the National Science Foundation under DMR Grant 906832 and Research Corporation Grant 7889.

  8. External Examining: Fit for Purpose?

    ERIC Educational Resources Information Center

    Bloxham, Sue; Price, Margaret

    2015-01-01

    In a context of international concern about academic standards, the practice of external examining is widely admired for its role in defending standards. Yet a contradiction exists between this faith in examining and continuing concerns about standards. This article argues that external examining rests on assumptions about standards which are…

  9. Choosing a Truly External Evaluator

    ERIC Educational Resources Information Center

    Ray, Marilyn

    2006-01-01

    This scenario discusses a situation in which a proposal has been published by a consortium of foundations for an "external" evaluator to evaluate a replication at two new sites of a program they have been funding for many years. A proposal is received from Dr. Porto-Novo, who has been the external evaluator of the initial program for about 10…

  10. The heterogeneous gas with singular interaction: generalized circular law and heterogeneous renormalized energy

    NASA Astrophysics Data System (ADS)

    García del Molino, Luis Carlos; Pakdaman, Khashayar; Touboul, Jonathan

    2015-01-01

    We introduce and analyze d-dimensional Coulomb gases with random charge distribution and general external confining potential. We show that these gases satisfy a large-deviation principle. The analysis of the minima of the rate function (which is the leading term of the energy) reveals that, at equilibrium, the particle distribution is a generalized circular law (i.e. with spherical support but not necessarily uniform distribution). In the classical electrostatic external potential, there are infinitely many minimizers of the rate function. The most likely macroscopic configuration is a disordered distribution in which particles are uniformly distributed (for d = 2, the circular law), and charges are independent of the positions of the particles. General charge-dependent confining potentials unfold this degenerate situation: in contrast, the particle density is not uniform, and particles spontaneously organize according to their charge. In this picture the classical electrostatic potential appears as a transition at which order is lost. Sub-leading terms of the energy are derived: we show that these are related to an operator, generalizing the Coulomb renormalized energy, which incorporates the heterogeneous nature of the charges. This heterogeneous renormalized energy informs us about the microscopic arrangements of the particles, which are non-standard, strongly dependent on the charges, and include progressive and irregular lattices.