Perpendicular Angle Research Articles

Spin dependent scattering of Cs atoms from ferromagnetic surfaces

We have investigated spin dependencies of the survival probability of spin-polarized cesium atoms scattered at Fe(0 0 1) in the resonant charge transfer process theoretically taking the difference of the spin densities of states of the surface between majority and minority spins into account. The survival probability was found sensitive to the spin DOS and to have strong dependence on the perpendicular velocity and incident angle when the spin polarization is parallel to the majority spin.

Longitudinal drift of substorm electrons as the reason of impulsive precipitation events and VLF emissions

Abstract. Using the data from satellite CRRES and three geostationary LANL spacecraft, the propagation of an electron cloud from midnight to the evening sector is investigated. An electron cloud was injected during a weak isolated substorm that developed on a quiet geomagnetic background. It is found that within the local time sector from 03:00 until at least 08:00 MLT, the propagation of electrons at perpendicular pitch-angles is well described by a simple model of drift in the dipole magnetic field. The flux levels in the field-aligned electrons increase simultaneously with the flux at perpendicular pitch angles, which is attributed to the pitch angle diffusion by the whistler mode. This pitch-angle diffusion leads to precipitation of electrons from a drifting cloud and an increase in the ionospheric electron density, simultaneously observed above Tromsø, Norway, by the EISCAT UHF radar in the morning sector (04:40–05:25 MLT). The precipitation develops as quasi-periodic pulses with a period of about 100 s. We discuss the models of pulsating precipitation due to the whistler cyclotron instability and show that our observations can be explained by such a model.

Substorm associated magnetotail energetic electrons pitch angle evolutions and flow reversals: Cluster observation

The Cluster satellites observed a distinct pattern in the evolution of energetic electron pitch angle distributions on November 13, 2003, in the mid‐tail (radius >10RE) associated with intensifications of these electron fluxes that accompanied an observed local dipolarization of the magnetic field. The intensity of electrons (20–200 keV) were first observed to increase for perpendicular pitch angles (pancake distribution), then evolve into isotropic distributions, then further evolve into mixed distributions ‐ a combination of perpendicularly peaked distributions and beamlike distributions (cigar distribution), and at the end of each of three episodes always evolved into a beamlike or field‐aligned distribution. This evolution pattern seen at a relative fixed observing (satellite) location usually developed within the locally observed dipolarization time scale. We have interpreted this pattern to indicate that electrons were coming from different regions along the magnetotail and have gotten accelerated differently. This has led us to suggest and present a model in which Fermi acceleration dominates for electrons that are accelerated from the reconnection region, while betatron acceleration dominates for electrons that are accelerated from the mid‐tail region that is very close to the satellite location.

Guidelines for Noninvasive Vascular Laboratory Testing: A Report from the American Society of Echocardiography and the Society of Vascular Medicine and Biology

Accompanying the rapid growth of interest inpercutaneous vascular interventions, there hasbeen increasing interest among cardiologists inperforming noninvasive vascular testing using ul-trasound. In an attempt to provide recommenda-tions on the best practices in vascular laboratorytesting, this report has been prepared by a writinggroup from the American Society of Echocardiog-raphy (ASE) and the Society of Vascular Medicineand Biology. The document summarizes principlesintegral to vascular duplex ultrasound–includingcolor Doppler, spectral Doppler waveform analy-sis, power Doppler, and the use of contrast.Appropriate indications and interpretation of ca-rotid artery, renal artery, abdominal aorta, andperipheral artery ultrasound imaging are de-scribed. A dedicated section summarizes noninva-sive techniques for physiologic vascular testing ofthe lower extremity arteries–including measure-ment of segmental pressures and pulse volumeplethysmography. The use of exercise testing inthe evaluation of peripheral artery disease, ultra-sound evaluation of the lower extremities afterpercutaneous revascularization, and the diagnosisand management of iatrogenic pseudoaneurysm(PSA) is also discussed. A section on the importanttopic of vascular laboratory accreditation is in-cluded. Finally, additional details regarding propertechnique for performance of the various vasculartests and procedures are included in the Appen-dix.

Simple synthesis and characteristics ofMo/MoS2 inorganic fullerene-like and actinomorphic nanospheres with core–shell structure

High yields of Mo/MoS2 inorganic fullerene-like and actinomorphic nanospheres with a core–shell structure havebeen successfully synthesized by the one-step reaction of sulfur and molybdenumnanospheres under a hydrogen atmosphere, in which the Mo nanosphereswere prepared by the wire electrical explosion method. The shell thickness ofMoS2 is about 4–10 nm and exhibit an expansion of about 4.2–1% along thec-axis. Observed from high-resolution transmission electron microscopyimages, unreacted molybdenum lying between the (002) layers ofMoS2 contributes to the larger expansion besides the strain in the bentlayer and the crystal defects; the preferred growth orientations forMoS2 on the surface of Mo have two directions under different annealing temperatures: parallel tothe (110) plane of Mo, presenting an actinomorphic phase, and perpendicular or havingcertain angles to the (110) plane, showing a fullerene-like phase. The actinomorphicMo/MoS2 can be used for catalysis and intercalation. The fullerene-like phase can be applied as asolid lubricant to enhance the structural rigidity and load bearing capacity of hollowMoS2. In addition, the core–shell nanospheres exhibit a little higher onset temperature and a narrowtemperature range against oxidation with a weaker exothermic peak than conventional2H-MoS2.

Prevention of painful neuromas by oblique transection of peripheral nerves

Neuroma formation often occurs at the proximal stump of the transected nerve, complicating the healing process after gap injuries or nerve biopsies. Most such neuromas cause therapy-resistant neuropathic pain. The purpose of this study was to determine whether oblique transection of the proximal stump of the sciatic nerve can prevent neuroma formation. The sciatic nerves of 10 rats were transected unilaterally at an angle of 30 degrees, and the peripheral segments of the nerves were removed. In 10 control animals the sciatic nerves were transected at a perpendicular angle. Twenty weeks after surgery the nerves were reexposed and collected. The presence of neuromas was determined by two board certified pathologists on the basis of histopathological evaluations. The oblique transection of peripheral nerves, contrary to perpendicularly transected nerves, is rarely followed by classic neuroma development. Moreover, neuropathic pain is significantly reduced compared with that following the traditional method of nerve transection.

Hypertrophic Cardiomyopathy

Hypertrophic Cardiomyopathy

How do Highways Influence Snake Movement? Behavioral Responses to Roads and Vehicles

Roads affect animal survivorship and behavior and thereby can act as a barrier to movement, which exacerbates habitat fragmentation and disrupts landscape permeability. Field experiments demonstrated that interspecific differences in ecology and behavior of snakes affected responses of species when they encountered and crossed roads. The probability of crossing a road varied significantly among southeastern U.S. snakes, with smaller species exhibiting higher levels of road avoidance. Species also differed significantly in crossing speeds, with venomous snakes crossing more slowly than nonvenomous ones. All species crossed at a perpendicular angle, minimizing crossing time. A model incorporating interspecific crossing speeds and angles revealed that some species cannot successfully cross highways with high traffic densities. Individuals of three species immobilized in response to a passing vehicle, a behavior that would further prolong crossing time and magnify susceptibility to road mortality. Identifying direct and indirect effects of roads on snakes is essential for mitigating road impacts and for designing effective transportation systems in the future.

A Yellow Ring-shaped Macular Reflection

To describe a yellow ring-shaped reflection in the macula of healthy subjects observed with a common indirect ophthalmoscope. Observational case series. Fundus photographs of the macula were acquired with a slit lamp and 90-diopter lens in 5 healthy subjects (age range, 23-50 years) at a perpendicular angle and at an oblique angle to the retina. The perpendicular fundus photographs showed a yellow ring-shaped reflection with a diameter of approximately 5 degrees. The oblique photographs had a dark red spot in the center. To our knowledge, this phenomenon has hitherto escaped attention in the literature. We conclude that the shape, size, and location of the yellow reflection are consistent with a cone origin. This observation may be used for diagnostic purposes.

Medium energy pitch angle distribution during substorm injected electron clouds

An investigation of pitch angle resolved electron data of energy <47 keV made by the MPA instrument on LANL geosynchronous satellites reveals a signature of symmetric peaks in the pitch angle distributions, observed to expand from being nearly at perpendicular pitch angles (∼90°) to nearly field aligned at lower energies. This feature is seen in almost every interval of increased fluxes at geosynchronous orbit. A closer examination reveals the expansion of the peak in pitch angle to be such that the corresponding parallel velocity (along B) is constant. In some time intervals there are simultaneous symmetric peaks in more than one energy band and the parallel energy corresponding to the symmetric peaks is seen to vary as function of time. The observations might be explained by particles interacting with whistler mode chorus through Landau resonance, diffusing particles with parallel velocity near the phase velocity of the waves.

Robot docking with neural vision and reinforcement

Abstract We present a solution for robotic docking, i.e. approach of a robot toward a table so that it can grasp an object. One constraint is that our PeopleBot robot has a short non-extendable gripper and wide ‘shoulders’. Therefore, it must approach the table at a perpendicular angle so that the gripper can reach over it. Another constraint is the use of vision to locate the object. Only the angle is supplied as additional input. We present a solution based solely on neural networks: object recognition and localisation is trained, motivated by insights from the lower visual system. Based on the hereby obtained perceived location, we train a value function unit and four motor units via reinforcement learning. After training the robot can approach the table at the correct position and in a perpendicular angle. This is to be used as part of a bigger system where the robot acts according to verbal instructions based on multi-modal neuronal representations as found in language and motor cortex (mirror neurons).

AlGaInN Violet Laser Diodes Grown on GaN Substrates with Low Aspect Ratio

AlGaInN violet laser diodes grown on GaN substrates have been studied. Waveguide simulations have been performed and perpendicular radiation angles have been investigated. A peculiar layer structure has been proposed to reduce the perpendicular radiation angle and compared with a conventional laser. The laser structure has an n-cladding layer consisting of three AlGaN films, the middle film of which has relatively high Al composition. A laser diode with an optimized structure has been fabricated. The threshold current density and slope efficiency have been 2.9 kA/cm2 and 1.4 W/A, respectively. The perpendicular radiation angle has been as small as 16.2°. The AlGaInN violet laser diode with a low aspect ratio of 1.6 and a small threshold current of 29 mA has been realized.

Intra-atrial ECG is not a reliable method for positioning left internal jugular vein catheters

ECG guidance is widely used for positioning central venous catheters (CVCs) in the superior vena cava. We noticed a higher incidence of a more perpendicular angle between the catheter tip and the vessel wall after left-sided ECG-guided catheter positioning. To investigate the value of left-sided ECG guidance, we performed this prospective study. Of 114 patients, 53 were randomized to right and 61 to left internal jugular vein catheterization using a triple lumen catheter. Three methods to ascertain catheter tip position were sequentially applied in each patient, and the insertion depths (ID) obtained using each of the three methods were recorded: (i). ECG guidance with a Seldinger guide wire (ID-A); (ii). ECG guidance with saline 10% used as an exploring electrode (ID-B); (iii). from position ID-B, the catheter was rotated and advanced until all three lumina could be aspirated easily. The catheter was fixed in that position (ID-C). To determine final catheter tip position, intraoperative transoesophageal echocardiography (TOE) and a postoperative chest X-ray (CXR) were performed. The depth of insertion of a catheter using the three methods varied significantly in left-sided (P<0.001), but not in right-sided catheters. Forty-eight of 57 (84%) left-sided CVCs, correctly positioned according to ECG guidance, had to be advanced further to achieve free aspiration through all three lumina. By this stage, five of the catheter tips had been positioned in the upper right atrium as demonstrated by TOE. There were 13 malpositions (23%) after left-sided insertion. In nine catheter malpositions, undetected by ECG guidance, the angle between the catheter tip and the lateral wall of the superior vena cava exceeded 40 degrees on CXR. Intra-atrial ECG does not detect the junction between the superior vena cava and right atrium. It is not a reliable method for confirming position of left-sided CVCs. Post-procedural CXRs are recommended for left-sided, but not right-sided CVCs.

Q-Switched 2.94-microm Er:YAG laser trephination with convergent and divergent cut angles for penetrating keratoplasty.

To study the morphologic properties of perpendicular (P), convergent (C), and divergent (D) cut angles using different speeds of rotations during donor and recipient nonmechanical trephination for experimental penetrating keratoplasty. With a Q-switched 2.94-microm Er:YAG laser corneal trephination was performed in 150 enucleated porcine eyes using ceramic open masks with 8 "orientation teeth/notches" and an automated globe rotation device allowing different cut angles [0 degree (P), 10 and 20 degrees (C and D)] toward the optical axis and variation of the rotation speed [3, 7, and 11 rotations per minute (rpm)]. The regularity of the cut (I, regular; II, slightly irregular; III, irregular) was assessed by light microscopy. The area of thermal damage and the number and size of "spikes" in the stroma at the superficial, intermediate and deep level of the excision were analyzed using digital images and the Optimas image processing software. The regularity of the cut was classified as I in 42%/22% of donor/recipient and as II in 41%/56%, respectively. The thermal damage was least expressed with D20 degree cut angle and donor mask (P < 0.01). With all cut angles and speeds of rotation, thermal damage at the deep level of excision was significantly smaller (P < 0.01). With different speeds of donor rotations, the thermal damage showed no significant difference. With recipient trephination, the thermal damage at the deep level was greatest with 7 rpm (P < 0.01). The number and size of spikes of thermal damage with donor and recipient masks were significantly smaller in the deep stroma (P < 0.01). Q-switched Er:YAG laser trephination with appropriate settings results in low thermal damage zones at the cut margin. Different cut angles and speeds of trephination may affect the cut performance and quality of the excision. In our study, low rotation speed and divergent donor cut angles showed the best results. The cut quality and the small thermal damage with the Q-switched 2.94-microm Er:YAG laser seem to be tolerable for corneal trephination. Therefore, this modality may be a low-cost, easy-to-handle alternative for nonmechanical corneal transplantation in humans.

Morphology, kinematics and modelling of the elliptical planetary nebula Sa 2-21

The little studied PN, Sa 2-21 has been observed using the Manchester echelle spectrometer at the Anglo-Australian telescope. Narrow band, long-slit spectra were obtained at six positions over two perpendicular position angles in both the [N II] λ6584 A and [O III] λ5007 A emission lines. An [O III] halo has been detected for the first time. A morphological modelling program was used to help determine the geometry, structure and kinematics of this ellipsoidal PN. It is proposed that the structure includes a pair of mid-latitude rings of IN II] emission, not previously seen in elliptical PNe. Radial spokes of [O III] emission have been detected in the main nebular shell indicating the presence of dynamical instabilities.

Etch characteristics of Bi4−xEuxTi3O12 (BET) thin films using inductively coupled plasma

Bi 4−x Eu x Ti 3 O 12 (BET) thin films were etched by inductively coupled CF4/Ar plasma. We obtained the maximum etch rate of 78 nm/min at the gas mixing ratio of CF4 (10%)/Ar (90%). This result may suggest that sputtering by Ar ions is more effective than chemical etching by fluorine atoms for Bi4−xEuxTi3O12 (BET) etching. The variation of volume density for F and Ar atoms are measured by optical emission spectroscopy. As CF4 increased in CF4/Ar plasma, the emission intensities of F increase but Ar atoms decrease, which confirms our suggestion that the etch rate of BET thin film and emission intensity of an Ar+ ion is proportional to the volume density of Ar atoms. From x-ray photoelectron spectroscopy, the intensities of the Bi–O, the Eu–O, and the Ti–O peaks are changed with increasing CF4 concentration. By pure Ar plasma, the intensity peak of the oxygen–metal (O–M: TiO2, Bi2O3, Eu2O3) bond seemed to disappear while the intensity of the pure oxygen peak showed an opposite tendency. After the BET thin films were etched by CF4/Ar plasma, the peak intensity of the O–M bond increases slowly, but more quickly than that of peak belonging to pure oxygen atoms due to the decrease of Ar ion bombardment. These results indicate that Bi and Eu have a reaction with little F and those are removed predominantly by argon-ion bombardment. However, Ti reacts with little F radicals and is mainly removed by chemically assisted physical etching. To fabricate high-density ferroelectric random access memory devices, etch processes require stringent critical dimension control to ±0.02 μm and steep etch profiles over 70°. From the scanning electron microscopy, we had an almost perpendicular taper angle of over 85°.

High-order harmonic generation in crossed laser beams

We investigate laser high-order harmonic generation in the presence of interfering light. A relatively weak interfering pulse intersects the primary harmonic-generating laser pulse at the focus. The influence on the harmonic-generation process is studied at near-counterpropagating and at perpendicular angles. The interfering beam creates a standing intensity and phase modulation, which disrupts microscopic phase matching and shuts down local high-harmonic production. Simple quasi-phase matching is demonstrated in which the interfering light disrupts harmonic generation in a portion of the laser focus. Under poor phase-matching conditions, perpendicularly propagating light is shown to enhance the 23rd harmonic generated in argon.

Structural studies of mixed-ligands copper(II) and copper(I) complexes with the rigid nitrogen ligand: bis[ N-(2,6-diisopropylphenyl)imino]acenaphthene

The crystal structure of the rigid bidentate nitrogen ligand bis[ N-(2,6-diisopropylphenyl)imino]acenaphtene (abbr. o, o′- iPr 2C 6H 3-BIAN) and three mixed- ligand copper complexes, namely [Cu II(AcOH)( o, o′- iPr 2C 6H 3-BIAN)Cl 2] (1), [Cu II(acac)(AcOH)( o, o′- iPr 2C 6H 3-BIAN)]·(ClO 4) (2) (where AcOH=acetic acid and acac=acetylacetonate) and [Cu IBr( o, o′ -iPr 2- p-BrC 6H 2-BIAN)] 2 ( 3) are reported. In complexes 1 and 2, the coordination around the copper(II) centre is distorted square pyramidal with acetic acid molecule in the apical position. Two imine nitrogen atoms of o, o′- iPr 2C 6H 3-BIAN are occupying the basal plane together with two chloride atoms in case of 1 and two oxygen atoms (from acac ligand) in case of 2. In complex 3 the copper(I) ion is tetrahedrally surrounded by two imine nitrogen atoms of o, o′- iPr 2- p-BrC 6H 2-BIAN, and by two bridging bromide atoms. Complex formation is followed by certain structural changes inside the rigid N–N ligand. Such changes led to an increased planarity of the o, o′- iPr 2C 6H 3-BIAN backbone, and produced a nearly perpendicular angle between the naphthalene and the aromatic imine planes.

Mutual Interference of Pheromone Traps Within Trap Lines on Captures of Boll Weevils (Coleoptera: Curculionidae)

Abstract Traps baited with the synthetic aggregation pheromone of the boll weevil (Anthonomus grandis Boheman) are often used to monitor population fluctuations, distribution, and behavior. However, many factors generate variability in daily captures, making interpretation of trapping data difficult. Previous studies have shown that wind speed in the microenvironment around a trap can greatly affect numbers captured on a given day. It is possible that variation in air movement may also generate variation in trap captures through its effects on the pheromone plume. The current study was conducted to determine whether five traps placed in a line at two commonly used spacings (15 and 20 m) interfere with one another. There was no evidence for interference on days when winds struck the trap line at a nearly perpendicular angle. However, for both spacings, there were significant and substantial effects of relative trap placement within a line on days when winds struck it at an angle (>22.5°) away from the perp...

CF4/O2Gas Chemistry에 의해 식각된 Ru 박막의 표면 반응

Ru thin films were etched using CF/<TEX>$_4$</TEX>O<TEX>$_2$</TEX> plasma in an ICP (inductively coupled plasma etching) system. The maximum etch rate of Ru thin films was 168 nm/min at a CF<TEX>$_4$</TEX>/O<TEX>$_2$</TEX> gas mixing ratio of 10 %. The selectivity of SiO<TEX>$_2$</TEX> over Ru was 1.3. From the OES (optical emission spectroscopy) analysis, the optical emission intensity of the O radical had a maximum value at 10% CF<TEX>$_4$</TEX> gas concentration and drcrease with further addition of CF4 gas, but etch slope was enhanced. From XPS (x-ray photoelectron spectroscopy) analysis, the surface of the etched Ru thin film in CF<TEX>$_4$</TEX>/O<TEX>$_2$</TEX> chemistry shows Ru-F bonds by the chemical reaction of Ru and F. RuF<TEX>$_{x}$</TEX> compounds were suggested as a surface passivation layer that reduces the chemical reactions between Ru and O radicals. From a FE-SEM (field emission scanning electron microscope) micrograph, we had an almost perpendicular taper angle of 89<TEX>$^{\circ}$</TEX>.>.