Increasing radiation power in half width microstrip leaky wave antenna by using slots technique

<p class="Default">The radiation power in the endfire is decreased while the main beam of half substrate integrated waveguide scan from broadside to endfire in a forward. The design of half-width microstrip leaky-wave antenna (HW-MLWA) has been presented in this work to increase the power radiation near endfire by using the slots technique in the radiation element. This slot leads to a decrease the cross-polarization. The proposed design comprises one element of HW-MLWA with repeated meandered square slots in the radiation element. One aspect of this antenna is generated by using a half substrate integrated waveguide with a full tapered feed line. The proposed antenna was terminated by load of 50 Ω, and feed on the other end of the antenna. Finally, the suggested design is simulated and acceptable results were found. The released gain is increased from 10.6 dBi to 12 dBi at 4.3 GHz. This design is suitable for unmanned aerial vehicle UAVs at C band application.</p>

Super-Accuracy Calculation for the Half Width of a Voigt Profile

A simple approximation scheme to describe the half width of the Voigt profile as a function of the relative contributions of Gaussian and Lorentzian broadening is presented. The proposed approximation scheme is highly accurate and provides an accuracy better than 10−17 for arbitrary αL/αG ratios. In particular, the accuracy reaches an astonishing 10−34 (quadruple precision) in the domain 0 ≤ αL/αG ≤ 0.2371 ∪ αL/αG ≥ 33.8786.

Outcomes of half-width vertical rectus transposition augmented with posterior fixation sutures for sixth cranial nerve palsy

AIM: To describe the experience with half-width vertical muscles transposition (VRT) augmented with posterior fixation sutures. METHODS: The clinical charts of all patients, who underwent half-width VRT augmented with posterior fixation sutures for sixth cranial nerve palsy from January 2003 to December 2018, were retrospectively reviewed. For each patient, pre- and post-operatively, the largest measured angle was used for the calculations, usually resulting with the angle for distance, except in young infants, where measurements were made at near fixation using the Krimsky test. RESULTS: Fifteen patients met the inclusion criteria for the study, of them 9 (60.0%) had also medial rectus muscle recession at the time of surgery. Mean follow-up period was 21.4±23.2mo (range 1.5-82mo). Preoperative mean esotropia was 51.3±19.7 prism diopter (PD; range 20-90 PD). Postoperative mean deviation on final follow-up was 7.7±20.2 PD (range -40 to 35 PD; P=0.018). In all patients with preoperative abnormal head position, improvement was noted. Ten (66.7%) patients had improvement in abduction and 10 (66.7%) patients reported improvement in their diplopia, by final follow-up. The addition of medial rectus recession was correlated with a larger change in postoperative horizontal deviation compared to baseline (P=0.026). Two (13.3%) patients developed a vertical deviation in the immediate postoperative period which had resolved in one of them. CONCLUSION: Half-width VRT augmented with posterior fixation suture, with or without medial rectus muscle recession, is an effective and safe procedure for esotropia associated with sixth cranial nerve palsy. A major improvement in the angle of deviation is expected. Most patients will have improvement in their abnormal head position and diplopia.

INVESTIGATION OF THE SURFACE PLASMON-POLARITONS EXCITATION EFFICIENCY ON ALUMINUM GRATINGS, TAKING INTO ACCOUNT DIFFRACTED RADIATION

Detailed studies of the efficiency of excitation of surface plasmon-polaritons (SPP) on aluminum gratings with a period a = 694 nm, which exceeds the incident wavelength of λ = 632,8 nm, have been carried out. The gratings relief depth (h) range was 6–135 nm. Research samples were formed on As40S30Se30 chalcogenide photoresist films using interference lithography and vacuum thermal deposition of an opaque aluminum layer about 80 nm thick. An atomic force microscope was used to determine the groove profile shape and the grating relief depth. The study of the SPP excitation features was carried out on a stand mounted on the basis of a G5M goniometer and an FS-5 Fedorov stage by measuring the angular dependences of the intensity of specularly reflected and diffracted p-polarized radiation of He-Ne laser. When determining the SPP excitation efficiency, the resonance values of both specular reflection and reflection in the -1st DO were taken into account. It was found that the dependence of the integral plasmon absorption on the grating modulation depth (h/a) is described by a somewhat asymmetric curve with a wide maximum, the position of which corresponds to an h/a value of about 0.07 and a half-width of about 0.123. This allows to excite SPP with an efficiency ≥ 80% of the maximum value on the gratings with the 0,05-0,105 h/a range. The half-width of the plasmon minimum of the reflection in the -1st DO is less than in the specular reflection, which can increase sensitivity of sensor devices when registering the shift of the minimum from angular measurements. The dependence of the half-width of the SPP reflection minima on the grating modulation depth is close to quadratic. In the investigated h/a range (from 0.009 to 0.194), the maximum dynamic range of the reflection coefficient is two orders of magnitude and is achieved in specular reflection for gratings with h/a ≈ 0.075.

Donor Site Evaluation after Full-Width Metatarsal Transfer for Metacarpal Reconstruction in Severe Thumb Hypoplasia: A Clinical Retrospective Study

Background: Pollicization remains the default treatment for severe thumb hypoplasia, while the metatarsal transfer is an effective choice for metacarpal reconstruction, with competitive outcome of reconstructed thumb. However, rare researches focused on the outcome of donor foot of the metatarsal transfer. The purpose of this study was to evaluate the short-term outcome of donor foot after full-width metatarsal transfer for Manske Type IIIB and IV thumb hypoplasia.Methods: Fourteen patients with Manske Type IIIB and IV thumb hypoplasia were enrolled in the study. A full-width metatarsal graft (vascularised, from the second metatarsal or non-vascularised, from the fourth metatarsal) was harvested; an adjacent half-width graft from the third metatarsal was transposed horizontally to replace the donor defect. Objective and subjective evaluations were performed at least 12 months postoperatively. The appearances of the toes and the radiographic findings of the metatarsals were evaluated by two authors, the length and width of the metatarsals were measured on digital anteroposterior radiographs using a paired sample t test. The parental satisfaction was evaluated using a self-administered questionnaire. Results: Among these 14 patients (eight type ⅢB and six type Ⅳ thumbs), there were ten male and four female patients. The mean age at operation was 34.2 months (range: 14 to 127 months), and the mean follow-up was 16.1 months (range: 12 to 30 months). Toe lengthening, toe overriding, and synostosis between the metatarsals were observed in two, two and two patients; toe shortening, toe deviation, metatarsal lengthening and metatarsal angulation were observed in one, one, one and one patient. The lengths of third and fourth metatarsals in donor site were significantly larger than those in contralateral side, while the widths of third and fourth metatarsals were not significantly different between donor and contralateral sides. The mean score in the parental satisfaction questionnaire (full score, 30) was 27.2, (range: 17 to 30), which rated as “good”. Conclusions: Following full-width metatarsal transfer for Type IIIB and IV thumb hypoplasia, transposition of the adjacent half-width metatarsal for donor reconstruction results in minor donor deficit and overall parenteral satisfaction. Level of evidence: Ⅳ

Axisymmetric Loading of a Plate on a Local Support in the Framework of the Rodionova-Titayev-Chernykh Theory

The problem of an axisymmetric bending of a plate with constant thickness under its own weight is considered. The plate has a circular support. The problem is solved in an axisymmetric statement using a nonclassical shell theory of Rodionova-Titaev-Chernykh (RTCh), which takes plate compression in thickness into account. The solution for this theory is obtained using Godunov&#x27;s orthogonal sweep method. This solution is compared with the solution obtained using the general three-dimensional theory of elasticity, implemented in an open-source package Code_Aster using axisymmetric finite elements. The motivation for this study is the description of a stress-strain state of some variants of primary mirrors of large optical telescopes under the action of gravity. The obtained results characterizing the optical quality of the mirror surface are: the peak value (PV) and the root-mean square (RMS) of its displacement. A parametric study was carried out, i.e., the thickness of the plate and the half-width of the support were varied. The two methods were compared. It is shown that, as the plate thickness increases or the half-width of the support decreases, non-physical behaviour of the mirror surface takes place within the limits of the nonclassical theory of RTCh. A criterion of its applicability is therefore proposed.

Earthquake rupture properties in presence of thermal -pressurization of pore fluids

&lt;p&gt;Frictional heat generated in the fault core during earthquake rupture can raise the fluid pressure in the slip zone. Such increase of fluid pressure decreases the effective normal stress and thereby lowers the frictional strength of the fault. Therefore, thermal pressurization (TP) of pore fluid affects earthquake rupture processes including nucleation, propagation, and arrest. While the effects of pore pressure and fluid flow rate on dynamic weakening of faults are qualitatively understood, a detailed analysis of how TP affects&amp;#160; earthquake rupture parameters is needed to further deepen our understanding.&amp;#160;&lt;/p&gt;&lt;p&gt;In this study, we investigate the role of two key TP parameters -- hydraulic diffusivity and shear-zone half-width -- earthquake dynamics and kinematic source properties (slip, peak slip-rate, rupture speed and rise time). We conduct&amp;#160; a suite of 3D dynamic rupture simulations applying a rate-and-state dependent friction law (with strong velocity weakening) coupled with thermal-pressurization of pore fluids. Simulations are carried out with the open source software SeisSol (www.seissol.org). The temporal evolution of rupture parameters over ~1&amp;#8217;000 randomly&amp;#160; distributed on-fault receivers is statistically analyzed in terms of&amp;#160; mean variations of rupture parameters and correlations among rupture parameters.&amp;#160;&lt;/p&gt;&lt;p&gt;Our simulations reveal that mean slip decreases with increasing hydraulic diffusivity, whereas mean peak slip-rate and rupture speed remain nearly constant. On the other hand, we observe only a slight decrease of mean slip with increasing shear-zone half-width, whereas mean peak slip-rate and rupture speed show clear decrease. The faster diffusion of pore pressure as hydraulic diffusivity increases promotes faster increase of the effective normal stress (and fault strength) behind the main rupture front, reducing the rise time and, therefore also affecting mean slip. An increase in shear-zone half- width represents a heat source distributed over larger fault normal distance causing a second-order effect on mean slip. Additionally, our simulations reveal correlations among rupture parameters: 1) slip has weak negative correlation with peak slip-rate and negligible correlation with rupture speed, but a positive correlation with rise time, 2) peak slip-rate has a strong positive correlation with rupture speed, but a strong negative correlation with rise time, 3) rupture speed has strong negative correlation with rise time. We observe little or negligible effects of variations of hydraulic diffusivity and shear-zone half- width on the correlations between rupture parameters. Overall, our study builds a fundamental understanding on how thermal pressurization of pore fluids affects dynamic and thereby kinematic earthquake rupture properties. Our findings are thus important for the earthquake source modeling community, and particularly, for assessing seismic hazard due to induced events in geo-reservoirs.&lt;/p&gt;

Chaotic Oscillation of Satellite due to Aerodynamic Torque

This study presents the chaotic oscillation of the satellite around the Earth due to aerodynamic torque. The orbital plane of the satellite concurs is same as the tropical plane of Earth. The half-width of riotous separatrix is assessed utilizing Chirikov’s measure. Variety of boundary techniques shows that streamlined force boundary (ɛ), unpredictability of circle (e), and mass-proportion (ω0) convert normal wavering to the disorganized one. We studied the behavior of trajectories due to change in parameters with Lyapunov exponents and time series plots. The theory is applied to Resourcesat-1, an artificial satellite of the Earth.

DEPENDENCE OF SURFACE PLASMON POLYARITON EXCITATION EFFICIENCY ON ALUMINUM GRATINGS RELIEF DEPTH

An experimental study of the excitation of surface plasmonpolaritons (SPP) on aluminum diffraction gratings with a fixed period of 519 ± 0,5 nm and a variable modulation depth h/a(where h is the grating depth, and a – its period) was carried out. Gratings with a sine-like profile were formed on vacuum chalcogenide photoresists films by interference lithography and covered with an opaque aluminum film. A Dimension 3000 Scanning Probe Microscope was used to determine the grating groove profile. The characteristics of the SPP were determinedfor28 gratings with h/a ranged from 0,018 to 0,20, by measuring the dependences of specular reflection of p-polarized radiation of He-Ne laser on the angle of incidence, which was defined as the angle between the normal to the substrate plane and the laser beam. It was found that there is an optimal grating relief depth for a given excitation wavelength, which provides the maximum transfer of the incident electromagnetic wave energy to the surface plasmon-polariton mode.The dependence of the SPP excitation efficiency on the grating modulation depth has a maximum at a relatively small value of h/a ≈ 0.086. At such modulation depth the absorption of electromagnetic radiation of the incident laser beam is more than two orders of magnitude higher than the absorption of aluminum film with flat surface at the same angle of incidence. The position of the angle of resonant excitation of SPP practically does not change from h/a= 0,018 up to h/a ≈ 0,06. With further increase of h/a it begins to shift to the region of smaller incidence angles, with the rate of the shift accelerating gradually. With an increase of h/a, a decrease in the depth of the plasmon resonance and a significant increase in its half-width are also observed, and the dependence of the half-width of the SPP band on the modulation depth is close to quadratic. Using this grating-coupled SPP technique, the estimated thickness of air-formed oxide layer on the aluminum gratings surface (about 3.9 nm) is close to the value obtained in the literature with a set of complicated techniques.

CMEs in the Heliosphere: III. A Statistical Analysis of the Kinematic Properties Derived from Stereoscopic Geometrical Modelling Techniques Applied to CMEs Detected in the Heliosphere from 2008 to 2014 by STEREO/HI-1

We present an analysis of coronal mass ejections (CMEs) observed by the Heliospheric Imagers (HIs) onboard NASA’s Solar Terrestrial Relations Observatory (STEREO) spacecraft. Between August 2008 and April 2014 we identify 273 CMEs that are observed simultaneously, by the HIs on both spacecraft. For each CME, we track the observed leading edge, as a function of time, from both vantage points, and apply the Stereoscopic Self-Similar Expansion (SSSE) technique to infer their propagation throughout the inner heliosphere. The technique is unable to accurately locate CMEs when their observed leading edge passes between the spacecraft; however, we are able to successfully apply the technique to 151, most of which occur once the spacecraft-separation angle exceeds $180^{\circ }$ 180 ∘ , during solar maximum. We find that using a small half-width to fit the CME can result in inferred acceleration to unphysically high velocities and that using a larger half-width can fail to accurately locate the CMEs close to the Sun because the method does not account for CME over-expansion in this region. Observed velocities from SSSE are found to agree well with single-spacecraft (SSEF) analysis techniques applied to the same events. CME propagation directions derived from SSSE and SSEF analysis agree poorly because of known limitations present in the latter.