Variation Of Deflection Angle Research Articles

Study on baking deformation of the thin-walled arc chamber

A large scientific facility, High Intensity heavy-ion Accelerator Facility (HIAF), was being built to study basic and interdisciplinary sciences. To meet the requirements of magnetic rigidity for high-energy heavy ions, pulsed dipole magnets were used in Booster Ring (BRing). Therefore, the ceramic-lined thin-walled arc chambers with 0.3 mm shell were developed to reduce the eddy current resulting from the rapidly changing magnetic field. Furthermore, to satisfy the requirements of the beam lifetime, the pressure of BRing of the HIAF must be lower than 1 × 10−9 Pa. In-situ baking methods were used to obtain ultra-high vacuum. As the stiffness of the thin-walled arc chamber was poorer for evacuation and in-situ baking as a conventional way, it had to be controlled in the deformation and deflection angle. Thus, a deformation control method using springs was adopted. The results show that the longitudinal deformation of both different thin-walled chambers was controlled to within 0.3 mm, the radial deformation was controlled to within 0.8 mm and the variation of deflection angle was within 0.2°.

Research on the Stability of a New Mechanical Automatic Vertical Drilling Tool with the Torque-Increasing Device (Based on the Variation of Deflection Angles of the Stable Platform)

Research on the Stability of a New Mechanical Automatic Vertical Drilling Tool with the Torque-Increasing Device (Based on the Variation of Deflection Angles of the Stable Platform)

Angle control of far-field scattering based on all dielectric transmissive geometric phase metasurface in near-infrared region

For a common metasurface with gradual phase, once the metasurface element structure is designed, we can only obtain a limited number of abnormal deflection angles based on the different arrangement characteristics of the metasurface element structure. In order to obtain continuously varying anomalous deflection angles, we propose addition and subtraction operations for coded metasurface sequences. In order to simplify the design process, we use geometric phase coding units to construct coded metasurface sequences. We can perform the addition and subtraction operations for two initial encoding metasurface sequences, and a new encoding sequence can be obtained. And a new corresponding scattering angle can be achieved. One do not need to redesign the size of the coding unit, and a continuous variation of deflection angles can be realized.

Thermodynamics of AdS black holes from deflection angle formalism

We explore a link between AdS black hole thermodynamics and the deflection angle variation. Using the elliptic function analysis, we first study the phase structure of RN-AdS solutions in terms of optical aspects. Precisely, we find that the stable and the unstable phases can be derived from thermal variations of the deflection angle. Then, we investigate the Hawking-Page transition from the Gibbs energy optical dependence. Among others, we reveal that the large black hole/small black hole transition occurs at a specific value of the deflection angle. The finding results, being confirmed by the help of the Ruppeiner metric of the phase state space, indicate that the deflection angle can be exploited to unveil data on thermodynamics of AdS black holes.

Experiments and modeling of variable camber guide vane embedded with shape memory alloy plate

In this paper, a novel variable camber guide vane (VCGV) actuated with a shape memory alloy (SMA) plate is proposed to achieve active real-time control. An analytical model is proposed to describe the relationship of SMA plates with different thicknesses between the deflection angle and temperature. Then, a numerical model of the VCGV is established to design the shape of the VCGV. Moreover, experiments of this actuator and VCGV are conducted to explore the variation of deflection angles over time for the VCGV. Results show that the deflection angle of the VCGV can be actively controlled from 0° to 8.2°. This work is expected to widen the applications of SMAs in variable guide vanes.

Deflection of light and shadow cast by a dual-charged stringy black hole

Gravitational lensing and black hole shadows are one of the strongest observational evidences to prove the existence of black holes in the universe. The gravitational lensing arises due to the deflection of light by the gravitational field of a gravitating body such as a black hole. Investigation of the shadow cast by a compact object as well as deflection of light around it may provide the useful information about physical nature of the particular compact object and other related aspects. In this paper, we study the deflection of light by a dual-charged stringy black hole space–time derived in dilaton-Maxwell gravity. The variation of deflection angle with the impact parameter for different values of electric and magnetic charges is studied. We also study the shadow of this black hole space–time to obtain the radius of shadow cast by it. We have considered an optically thin emission disk around it and observed that there are not significant changes in the shadow cast by this black hole compared to well-known Schwarzschild black hole space–time in GR.

Underwater thrust vectoring based on inflated surface

ABSTRACTThe traditional way to underwater thrust vectoring is mainly based on a specially designed mechanical system which provides the propulsion system additional degree of freedom. This method is effective in field applications. However, there are several drawbacks such as complex structure and large dead weight. In this paper, a new type of thrust vectoring method, based on inflated surface is proposed. There are six inflatable surfaces uniformly distributed around the axis of the propulsor. The mechanism of this method is the Coanda effect. Through the control of the curvature of the surface, the deflection angle can be adjusted. The effect of the depth, the size and the curvature of the surface on the deflection angle is numerically studied. The deflection angle decreases with the depth, but increases with the surface size. The deflection angle first increases then decreases with the curvature due to flow separation. A maximum deflection angle of 14° is realised. The pressure and velocity distribution is given to illustrate the mechanism behind the variation of deflection angle in different cases.

Design and Optimization of Supersonic Intake

The ideal supersonic intake was designed using the Theta-Beta-Mach relations and a CAD modelling software. After the design was done the optimization part was carried out. Initially the easy method of cowl deflection angle variation was used to get the optimum results at a particular angle and then the pressure recovery was maximized using the intake bleed technique. The bleed technique was optimized by fixing the best location of bleed according to the shock reflections in the intake and then maximizing the results analyzing the problem for various bleed diameter values. The mesh resolution for all the analyses was taken constant along with the turbulence model and solution methods. The analyses were carried out completely considering the free flow exit condition in the intake and the back pressure condition was not taken into account due to time constraints. Therefore, the pressure recovery or the efficiency of the intake is judged solely on the minimum velocity achieved in the intake. This value was used to maximize the intake too.

Leaky waveguide deflector for 40 GS/s and 6 bits all-optical analog-to-digital converters

Analog-to-digital converters (ADC) are an important part of realizing direct digital receivers in future communication systems, where broad bandwidth, high effective number of bits, and low DC power consumption are an important requirement of achieving it at microwave frequencies. Due to a number of physical limitations of electrical ADC, design of an all-optical analog-to-digital converter (AOADC) is pursued and presented here based on highly stable mode-locked laser based clock signal pulses for optical sampling, and a combination of leaky waveguide optical deflector using electro-optical (EO) polymers and stationary optical windows followed with high-speed photodetectors as optical quantizer. The reported principle of the AOADC is to convert a broadband RF signal into a spatially sampled light using optical deflection angle variation before quantizing it using either binary or Gray coded optical windows. The design and modeling of an AOADC working up to 20 GHz RF frequencies (with Nyquist sampling rate of over 40 GS/s) and for providing a resolution of better than 6 bits with under 4W of power consumption. Performance is currently limited by both optical and microwave attenuation in the available EO polymers.

Design challenges of EO polymer based leaky waveguide deflector for 40 Gs/s all-optical analog-to-digital converters

Design challenges and performance optimization of an all-optical analog-to-digital converter (AOADC) is presented here. The paper addresses both microwave and optical design of a leaky waveguide optical deflector using electro-optic (E–O) polymer. The optical deflector converts magnitude variation of the applied RF voltage into variation of deflection angle out of a leaky waveguide optical beam using the linear E–O effect (Pockels effect) as part of the E–O polymer based optical waveguide. This variation of deflection angle as result of the applied RF signal is then quantized using optical windows followed by an array of high-speed photodetectors. We optimized the leakage coefficient of the leaky waveguide and its physical length to achieve the best trade-off between bandwidth and the deflected optical beam resolution, by improving the phase velocity matching between lightwave and microwave on one hand and using pre-emphasis technique to compensate for the RF signal attenuation on the other hand. In addition, for ease of access from both optical and RF perspective, a via-hole less broad bandwidth transition is designed between coplanar pads and coupled microstrip (CPW-CMS) driving electrodes. With the best reported E–O coefficient of 350pm/V, the designed E–O deflector should allow an AOADC operating over 44giga-samples-per-seconds with an estimated effective resolution of 6.5bits on RF signals with Nyquist bandwidth of 22GHz. The overall DC power consumption of all components used in this AOADC is of order of 4W and is dominated by power consumption in the power amplifier to generate a 20V RF voltage in 50 Ohm system. A higher sampling rate can be achieved at similar bits of resolution by interleaving a number of this elementary AOADC at the expense of a higher power consumption.

Effects of rotation on the trailing vortex and heat transfer from a horizontal rotating cylinder at higher Grashof number

In the present study, effects of rotation on the trailing vortex and heat transfer from a large diameter horizontal rotating cylinder in still air have been experimentally investigated whereas earlier studies considered cylinders with smaller diameters. As the rotational speed n is increased, the trailing vortex would deflect in the rotational direction, the flow state of air near the cylinder would vary from laminar to turbulent, the heat transfer would transit from pure natural convection to mixed convection, and finally to pure forced convection resulted from rotation, the trailing vortex would break down and disappear. The variation of deflection angles ω with the parameter Rer/Gr can be expressed as w=32.3Rer/Gr at lower rotational speed. The discriminant to determine the disappearance of trailing vortex can be presented as Rer2/Gr=7.51.

SU-8 as a Torsional Spring: Viscoelastic Creeping and Closed Loop Control

The torsional viscoelastic creeping and recovery of an SU-8 spring is reported by studying the deflection angle variation of a vertical comb-drive actuator suspended by an SU-8 spring at three different stress levels. A maximum creep of 0.43° (corresponding to a relative change of strain of 5.7%) is observed under a constant stress of 8.3 MPa in 1 h ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V =22$ </tex-math></inline-formula> .7 V). A capacitive readout circuit is designed to sense the torsional deflection of the comb-drive actuator. The circuit is capable of actuating and sensing the capacitance change by the same comb-drives with a resolution of 0.03° (corresponding to a capacitance resolution of 0.05 pF). The readout capacitance is then used as the input variable for a proportional-integral (PI) controller in order to eliminate the time and load dependent drift by creeping of the SU-8 spring. The PI controller is tuned by the Ziegler–Nichols method and has a settling time of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 2.3$ </tex-math></inline-formula> s for the output. Compared with the open loop deflection of 0.43°, the closed-loop deflection is reduced by a factor of 7 down to 0.06°. This controller error is prominent at high actuation voltages, and is attributed to the actuator’s lateral and vertical cross-sensitivity. [2014-0124]

Strong gravitational lensing in a charged squashed Kaluza–Klein Gödel black hole

In this Letter we investigate the strong gravitational lansing in a charged squashed Kaluza–Klein Gödel black hole. The deflection angle is considered by the logarithmic term proposed by Bozza et al. Then we study the variation of deflection angle and its parameters a¯ and b¯. We suppose that the supermassive black hole in the galaxy center can be considered by a charged squashed Kaluza–Klein black hole in a Gödel background. Then by the relations between lensing parameters and observables, we estimate the observables for different values of charge, extra dimension and Gödel parameters.

Deflected light structure in NaNH4SeO4·2H2O crystals

Deflection of light studies in function of temperature in NaNH4SeO4·H2O crystal is presented. At 180 K, this compound undergoes a para-ferroelectric/ferroelastic phase transition of the second order. It changes the symmetry from the orthorhombic symmetry class 222 (space group P212121) to the monoclinic symmetry class 2 (space group P21). A distinct deflection pattern, resulting from the ferroelastic domain structure, occurs in the low temperature phase. The intensity of deflected beams varies considerably with temperature. Detailed studies revealed the structure of deflected spots during cooling–heating cycle. These spots change intensity, become more dispersed and finally split with decreasing temperature. Moreover, a variation of deflection angles was observed. A possible explanation of these phenomena is given in a framework of crystals optics.