Shooting Method Research Articles

Analysis of OAR Doses in DMPO-Based Prostate IMRT

Radiotherapy plays an eminent role in the treatment of the prostate cancers with rotational radiotherapy taking the leading edge in the recent years. The study aims to find the relevance of the Direct machine parameter optimization (DMPO) based static gantry IMRT treatment planning in the step and shoot environment for ca prostate case with involved nodes in the era of rotational radiotherapy. Also we aim to determine the relation between the femur dose and the rectum dose, and mean rectum dose and rest rectum volume if any. 32 ca prostate patients were selected retrospectively for this study with prescribed dose of 68Gy (EQD2 72.08Gy α/β 10) and 50Gy in 25 fractions to the prostate and nodes respectively treated with the simultaneous integrated boost technique. The plans were done on a treatment planning system with DMPO algorithm and delivered using step and shoot method in LINAC. For PTV, 95% volume covering 100% prescribed dose was achieved with posterior rectum wall receiving less than 34Gy and organs at risk (OARs) within the tolerance limit. Along with the percentage volume of the rest rectum (rectum minus PTV with 0.5cm margin), the mean doses of rectum, rest rectum, rest bladder (bladder minus PTV with 0.5cm margin) and femur were noted. The relation between rectum mean dose and femur mean dose were studied. Also comparison was done between mean rectum dose and percentage (%)rest rectum volume. The doses received by 5% of the femoral heads were also studied. Plot of mean rectum dose versus mean femur dose received by each patients shows the inverse relation with correlation coefficient of -0.401 (p<0.05). Also the mean rectum dose and %rest rectum volume are inversely related with correlation coefficient of -0.81 (p<0.001). The mean of the dose received by 5% volume of right and left femur is 40.39±4.7Gy and 40.2±3.8Gy respectively with p<0.001. The mean dose of rectum was 36.5±5.5Gy with median dose of 37.6Gy. For rest rectum the mean dose was 28.7±5.6Gy with median dose of 27.8Gy. The mean dose of the left and right femoral heads and rest bladder were 24.2±4.5Gy, 23.7±4.5Gy and 31.6±6.2Gy respectively with p value <0.001. For an optimal plan for ca prostate case achieved on a TPS with DMPO algorithm, we could predict the mean dose of rectum to be 36.5±5.5Gy with 95% Confidence interval for mean femoral head dose of 23.9±4.2Gy. We could also infer that the femur dose and mean rectum dose, and the %rest rectum volume and mean rectum dose were inversely correlated with correlation coefficient of -0.401 and -0.810 respectively. Ca Prostate being the fourth most commonly occurring cancers is widely treated using radiotherapy as an important mode of treatment with different treatment techniques all over the world. Although the rotational radiotherapy delivers the treatment in comparably lower beam on time, the DMPO based static gantry IMRT plans still holds the dosimetric relevance with comparable OAR doses.

The hardwall method of solving the radial Schrödinger equation and unmasking hidden symmetries

Solving for the bound state eigenvalues of the Schrödinger equation is a tedious iterative process using the conventional shooting or matching method. In this paper, we bypass a eigenvalue's dependence on the eigenfunction by trying all eigenvalues to a desired accuracy. When the eigenvalue is known, the integration for the eigenfunction is then trivial. By outputting the radial distance at which the wave function crosses zero (the hardwall radius) for a given energy, the hardwall method automatically determines the entire spectrum of eigenvalues of the radial Schrödinger equation without iterative adjustments. Moreover, such a spherically symmetric hardwall can unmask the accidental degeneracy of eigenvalues due to hidden symmetries. We illustrate the method for the Coulomb, harmonic, Coulomb plus harmonic, and the Woods-Saxon potentials.

Features of conducting of geological exploration on shale gas in Volyno-Podillia at the regional stage of studying

Features of structural conditions of occurrence, gas accumulation, lithofacies, petrophysical and geochemical parameters, shielding factor, character-bearing shale gas saturation are fundamentally different from traditional gas deposits. Stratigraphic shale formation considered as a potential gas deposit. Considering this specificity its allocation and mapping must be executed at an early stage. To delineate gas bearing shale formations of Volyno-Podillia and allocation the most perspective areas offered a complexation of regional seismic survey 2D for great depths (two longitudal profiles of north-western stretch as it continued from the Lublin basin in Poland and 5 crosssections from southwest to the northeast with its total length of about 1500 linear kilometers) with electric prospecting methods of different modifications, caused polarization, electromagnetic methods of regional seismic exploration grids profiles, large-scale atmogeochemical shooting and other direct methods. As the completion of regional stage must be drilling of vertical parametric pilot wells with solid coring from perspective shale strata, laboratory studies of organic matter, of katagenesis, lithofacies and mineralogical composition of shales, their petrophysical and geochemical properties, modeling and testing perspective shale strata using multistage hydrogaps. Prospects of further exploration and it’s complex based on the results geologic-economic evaluation of perspective of petrogas of the region and obtaining results of works start-up phase.

Numerical Study of Performance of Porous Fin Heat Sink of Functionally Graded Material for Improved Thermal Management of Consumer Electronics

The ever-increasing demand for high-performance electronic and computer systems has unequivocally called for increased microprocessor performance. However, increasing microprocessor performance requires increasing the power and on-chip power density of the microprocessor, both of which are associated with increased heat dissipation. In recent times, thermal management of electronic systems has gained intense research attention due to increased miniaturization trend in the electronics industry. In this paper, we present a numerical study on the performance of a convective–radiative porous heat sink with functionally graded material (FGM) for improved cooling of various consumer electronics. For the theoretical investigation, the thermal property of the FGM is assumed as a linear and power-law function. We solved the developed thermal models using the Chebyshev spectral collocation method (CSCM). The effects of inhomogeneity index of FGM and convective and radiative parameters on the thermal behavior of the porous heat sink are investigated. This paper shows that increase in the inhomogeneity index of FGM and convective and radiative parameters improves the thermal efficiency of the porous fin heat sink. Moreover, for all values of Nc and Rd, the temperature gradient along the fin of FGM is negligible compared to HM fin in both linear and power-law functions. For comparison, the thermal predictions made in this paper using CSCM agree excellently with the established results of Runge–Kutta with shooting and homotopy analytical method.

Identifying linear absolute instabilities from differential eigenvalue problems using sensitivity analysis

Identifying the convective/absolute instability nature of a local base flow requires an analysis of its linear impulse response. One must find the appropriate singularity in the eigenvalue problem with complex frequencies and wavenumbers and prove causality. One way to do so is to show that the appropriate integration contour of this response, a steepest decent path through the relevant singularity, exists. Due to the inherent difficulties of such a proof, one often verifies instead whether this singularity satisfies the collision criterion. In other words, one must show that the branches involved in the formation of this singularity come from distinct halves of the complex wavenumber plane. However, this graphical search is computationally intensive in a single plane and essentially prohibitive in two planes. A significant computational cost reduction can be achieved when root finding procedures are applied instead of graphical ones to search for singularities. They focus on locating these points, with causality being verified graphically a posteriori for a small parametric sample size. The use of root-finding procedures require auxiliary equations, often derived by applying the zero group velocity conditions to the dispersion relation. This relation, in turn, is derived by applying matrix forming to the differential eigenvalue problem and taking the determinant of the resulting system of algebraic equations. Taking the derivative of the dispersion relation with respect to the wavenumbers generates the auxiliary equations. If the algebraic system is decoupled, this derivation is straightforward. However, its computational cost is often prohibitive when the algebraic system is coupled. Other methods exist, but often they can also be too costly and/or not reliable for two wavenumber plane searches. This paper describes an alternative methodology based on sensitivity analysis and adjoints that allow the zero group velocity conditions to be applied directly to the differential eigenvalue problem. In doing so, the direct and auxiliary differential eigenvalue problems can be solved simultaneously using standard shooting methods to directly locate singularities. Auxiliary dispersion relations no longer have to be derived, although it is shown that they are the algebraic equivalent of the auxiliary differential eigenvalue problems obtained by this alternative methodology. Using the latter dramatically reduces computational costs. The search for arbitrary singularities is then not only accelerated in single wavenumber planes but it also becomes viable in two wavenumber planes. Finally, the new method also allows group velocity calculations, greatly facilitating the verification of causality. Several test cases are presented to illustrate the capabilities of this new method.

Degree of cure, mechanical properties, and morphology of carbon fiber/epoxy- PP hybrids manufactured by a novel single shot method

The authors detail the creation of a hybrid multi-material structure via the injection of polypropylene (PP) with high ductility into a robust CF/Epoxy thermoset sheet. The purpose of this hybrid method involves combining the inherent properties of both thermoset and thermoplastic materials in a new hybrid structure while reducing the cycle time and tooling system. Specifically, the effect of pre-heating time, injection temperature, and injection speed rate on the deformation of the prepreg and polymer penetration through prepreg sheets were evaluated. The results of the experimental design indicated that the hybrid structures were manufactured with no penetration present in any combinations of parameters. An inadequate deformation characterized the samples created at a lower injection temperature, and pre-heating time, with insufficient adhesion as a result. High injection speed resulted in enhancing the formability and joinability. Also, the effect of the mentioned process parameters on the curing of prepreg sheet and bending behavior of final hybrid component were investigated through Differential Scanning Calorimetry (DSC), and the Three-point flexural test, respectively. Both DSC and Three-point test results illustrated the increase in pre-heating time, and the injection temperature enhanced the amount of curing and an increase of stiffness on the hybrid component.

Phytopathogenic and antagonistic potentialities of fungi associated with pistachio bark beetle, Chaetoptelius vestitus (Coleoptera, Curculionidae), infesting pistachio (Pistacia vera) in Tunisia.

This study investigated the biodiversity of fungi associated with the pistachio bark beetle, Chaetoptelius vestitus, in Tunisia. We evaluated the phytopathogenic activities and tested antagonistic potentialities with respect to phytopathogens. A total of 41 fungal isolates were randomly isolated from C.vestitus adults and galleries. We identified 28 species belonging to 13 genera using ITS sequences of the ribosomal RNA operons. Pathogenicity assays performed using the excised shoot method revealed that isolates Aal_io_1 (Alternaria alternata), Feq_io_1 (Fusarium equiseti), Fgra_io_1 (Fusarium graminearum), Fve_io_1 (Fusarium verticilloides), Tro_io_1 (Trichothecium roseum) and Nqu_io_1 (Nothophoma quercina) displayed a high pathogenic activity on pistachio stems. Estimation of the antagonistic potentialities of isolated fungi against several phytopathogenic isolates as tested using a dual-culture method showed that isolates Tpi_io_1 (Talaromyces pinophilus), Pbi_io_2 (Penicillium bilaiae), Asc_io_1 (Aspergillus sclerotiorum) and Gla_io_1 (Geosmithia lavendula) displayed a broad range of antagonistic activities. Fungi associated with C.vestitus had a variable range of pathogenic activity on pistachio stem. Phytopathogenic fungi were antagonized by different fungal isolates which could be promising in pistachio protection against phytopathogenic fungi. This study is the first that investigated the diversity of fungi associated with C.vestitus and evaluated both their phytopathogenic activity and antagonistic potential against fungal phytopathogens.

Initiation of fluid-induced fracture in a thick-walled hollow permeable sphere

The initiation of fluid-induced fracture in formations of permeable geomaterials subjected to quasi-stationary flow processes (drained response) can be strongly affected by Biot's coefficient and the size of the formation. The aim of this paper is to analyse the influence of these parameters on the initial fracture process of a thick-walled hollow permeable sphere subjected to fluid injection in the hole. Assuming that fracture patterns are distributed uniformly during the hardening stage of the fracture initiation process, the coupled fluid-solid problem is described by a nonlinear ordinary differential equation, which is solved numerically by means of finite differences combined with shooting and Newton methods. The finite difference code has also been validated in the elastic range, i.e., before initiation of fracture, against an original closed-form analytical solution of the above differential equation. The results show that the nominal strength of the sphere increases with increasing Biot's coefficient and decreases with increasing size.

Heat transfer characteristics on MHD Powell-Eyring fluid flow across a shrinking wedge with non-uniform heat source/sink

This report presents the flow and heat transfer characteristics on magnetohydrodynamic non-Newtonian fluid across a wedge near the stagnation point. The fluid flow is time independent and laminar. The radiation and irregular heat sink/source effects are deemed. The system of nonlinear ODEs is attained from PDEs by choosing the proper similarity transformations. Further, the well-known shooting and Runge-Kutta methods are utilized to acquire the problem’s solution subject to assumed boundary conditions. Figures are outlined to emphasize the impact of several parameters on the fields of velocity and temperature. Further, the rate of heat transfer and friction factor are also anticipated and portrayed with the assistance of table. Results indicate that the curves of velocity diminish with shrinking parameter, magnetic field parameter and material fluid parameter. Also the non-uniform heat source/sink parameters play a crucial role in the heat transfer performance.

Replacing the finite difference methods for nonlinear two-point boundary value problems by successive application of the linear shooting method

This paper studies numerical solution of nonlinear two-point boundary value problems for second order ordinary differential equations. First, it establishes a connection between the finite difference method and the quasi-linearization method. We prove that using finite differences to discretize the sequence of linear differential equations arising from quasi-linearization (Newton method on operator level) leads to the usual iteration formula of the Newton finite difference method. From the provided derivation, it can easily be inferred that such a relation holds also for the Picard and the constant-slope methods. Based on this result, we propose a way of replacing the Newton, Picard, and constant-slope finite difference methods by respective successive application of the linear shooting method. This approach has a number of advantages. It removes the necessity of solving systems of algebraic equations, hence working with matrices, altogether. Compared to the usual finite difference method with general solver, it reduces the number of computational operations from O ( N 3 ) , where N is the number of mesh-points, to only O ( N ) .

Process optimization of parameterized single shot method for a rapid production of photon sireve with direct write lithography

Photon sieves are promising elements for high-resolution optics. Fabrication of photon sieves is a raising topic of microscale optic fabrication. In order to fabricate photon sieves, many technics featured recently. Common production difficulties for fabrication are time consumption and complexity of process. This study provides direct write lithography process optimization for rapid and simple fabrication method. Using the direct write laser technology to pattern photoresist with parameterized single laser shot is the main idea of this study. Writing pattern with the parameterized single shot method gives good structures for photon sieves. Parameterized single shot method uses variable focus distance and modulation to write patterns with direct write lithography. Rapid patterning with better geometrical structures is the most important result of this study. In microscopic scale, geometrical results and time consumption are some drawbacks of continuous exposure laser method. It is inadequate for small structures such as photon sieves outermost pinholes. The main approach of this study is the optimization of the writing process for rapid and well-shaped production of smaller structures for photon sieves. The process optimization for Kloe direct write lithography system serves better structure for photon sieve pinhole than conventional writing methods.

Single-shot ptychographic iterative engine based on chromatic aberrations

A single shot ptychographic iterative engine based on chromatic aberrations is proposed to retrieve the object with fast data acquisition and convergence. In the imaging system, the specimen is irradiated by a RGB illumination source, and the RGB light transmitted through the specimen is recorded by a color sensor. There are three different sizes of the spots on the object surface generated by the lens with chromatic aberrations and the aperture stop, which can produce partially overlapping between adjacent wavelength illumination areas that will lock the object’s phase information and ensure retrieve the object successfully. In the reconstruction algorithm, an initial object guess is established by spectrum synthesis method to accelerate convergence and suppress noise. The data acquisition time is dramatically reduced by our proposed single shot method.

Time minimal saturation of a pair of spins and application in Magnetic Resonance Imaging

In this article, we analyze the time minimal control for the saturation of a pair of spins of the same species but with inhomogeneities of the applied RF-magnetic field, in relation with the contrast problem in Magnetic Resonance Imaging. We make a complete analysis based on geometric control to classify the optimal syntheses in the single spin case to pave the road to analyze the case of two spins. The Bocop software is used to determine local minimizers for physical test cases and Linear Matrix Inequalities approach is applied to estimate the global optimal value and validate the previous computations. This is complemented by numerical computations combining shooting and continuation methods implemented in the HamPath software to analyze the structure of the time minimal solution with respect to the set of parameters of the species. Symbolic computations techniques are used to handle the singularity analysis.

Kinematic Model Improvement of multi-degree-of-freedom Robotic Surgical Tool that Consists of Elastic Materials for further Accuracy

To enhance surgeons’dexterity in minimally invasive surgery, the authors have developed a four degree-of-freedom robotic surgical tool that has diameter of 3.5 mm using superelastic materials in previous study. The most notable feature of the tool is that the mechanism consists of multiple elastic elements, thus the tool has simpler and smaller structure than that of conventional robotic surgical tools. The developped robotic surgical tool showed promising results in evaluation, however, the control accuracy was found to be diminished when the tool bends in multi-degree-of-freedom. We have identified the cause of this issue as a mismatch of kinematic model and actual model because the current kinematic model was implemented without considering the interaction between springs. In this study, we applied Shooting method to solve the shape calculation on segmented mechanism model, and compared the results with FEM analysis. The results showed a better accuracy with the proposed method.

Size-dependent resonant response of a double-layered viscoelastic nanoresonator under electrostatic and piezoelectric actuations incorporating surface effects and Casimir regime

Nonlinear dynamics of a double-layer viscoelastic nanobeam embedded into an electromechanical system is investigated in this paper. The nanoelectromechanical system (NEMS) consists of two piezoelectric and Kelvin–Voigt viscoelastic nanobeams with visco-Pasternak medium in between. An electrostatic force which is the combination of DC and AC voltages is applied to the lower nanobeam through the fixed electrode. Taking into account both the small-scale effect and surface energy effect, the modified couple-stress theory together with Gurtin–Murdoch elasticity theory is implemented. As intermolecular interactions between the fixed and lower electrodes, the influence of Casimir regime on the dynamic behavior of the NEMS device is also included in the proposed model. The differential motion’s equations are derived by means of Hamilton’s principle and discretized to a set of nonlinear ODEs through Galerkin’s decomposition procedure. In order to capture the steady-state dynamic response of the system, a combined shooting and arclength continuation method is schemed. A comprehensive study has been carried out on the impact of viscoelasticity, size-dependency, surface effects, direct and alternating current voltages, piezoelectric voltage and visco-Pasternak parameters on the frequency-response behavior of the system near primary resonance. Furthermore, some bifurcation points in the frequency-response curves are addressed. The combined hardening–softening-type behaviors are observed in the dynamic response of the system. It has been shown that the nonlinear characteristics of the motion of the proposed NEMS device have sensitive-dependence on some of the mentioned parameters.

Computing heteroclinic orbits using adjoint-based methods

Transitional turbulence in shear flows is supported by a network of unstable exact invariant solutions of the Navier–Stokes equations. The network is interconnected by heteroclinic connections along which the turbulent trajectories evolve between invariant solutions. While many invariant solutions in the form of equilibria, travelling waves and periodic orbits have been identified, computing heteroclinic connections remains a challenge. We propose a variational method for computing orbits dynamically connecting small neighbourhoods around equilibrium solutions. Using local information on the dynamics linearized around these equilibria, we demonstrate that we can choose neighbourhoods such that the connecting orbits shadow heteroclinic connections. The proposed method allows one to approximate heteroclinic connections originating from states with multi-dimensional unstable manifold and thereby provides access to heteroclinic connections that cannot easily be identified using alternative shooting methods. For plane Couette flow, we demonstrate the method by recomputing three known connections and identifying six additional previously unknown orbits.

Entropy Generation Minimization in MHD Boundary Layer Flow over a Slendering Stretching Sheet in the Presence of Frictional and Joule Heating

In the present paper, we study the entropy analysis of boundary layer flow over a slender stretching sheet under the action of a non uniform magnetic field that is acting perpendicular to the flow direction. The effects of viscous dissipation and Joule heating are included in the energy equation. Using similarity transformation technique the momentum and thermal boundary layer equations to a system of nonlinear differential equations. Numerical solutions are obtained using the shooting and fourth-order Runge-Kutta method. The expressions for the entropy generation number and Bejan number are also obtained using a suggested similarity transformation. The main objective of this article is to investigate the effects of different governing parameters such as the magnetic parameter (M2), Prandtl number (Pr), Eckert number (Ec), velocity index parameter (m), wall thickness parameter (α), temperature difference parameter (Ω), entropy generation number (Ns) and Bejan number (Be). All these effects are portrayed graphically and discussed in detail. The analysis reveals that entropy generation reduces with decreasing wall thickness parameter and increasing temperature difference between the stretching sheet and the fluid outside the boundary layer. The viscous and magnetic irreversibilities are dominant in the vicinity of the stretching surface.

Influence of the Earth Rotation on Trajectory of a Returnable Hypersonic Cruise Vehicle

It is of high difficulty for a hypersonic vehicle to implement a hypersonic cruise flight and return to a scheduled airport without power. Accuracy of mission simulation and analysis is more crucial at this time. Under this circumstance, it is meaningful to discuss whether the earth rotation should be considered in the dynamic model and trajectory design. In this research, the dynamic equations in which the earth rotation is taken into consideration are derived for a hypersonic cruise vehicle. The direct shooting method is utilized for parameterization and discretization of the trajectory, so that the trajectory can be analyzed and simulated through numerical integration. Then, two groups of trajectory simulation results are presented. In each group, the only difference between the two trajectories is that whether the earth rotation is involved, and the two trajectories are compared with each other. For a returnable hypersonic cruise vehicle which returns to the ground without power, whether to involve the earth rotation in the dynamic model is discussed on the basis of the numerical results, and relevant suggestions are given for reference.

3D- flow of a Electrically Conducting and Dissipating Maxwell fluid treated with Ohmic Heating Convective boundary condition: Numerical Analysis

An analysis is made to study the effects of radiation, dissipation, Thermo-diffuso and Diffuso- thermo on MHD 3D Maxwell flow past a stretching permeable sheet with resistive heating. Transforming the governing dimensional boundary layer equations using three dimensional similarity transformations and then the resultant equations are numerically solved by employing Shooting method. The effect of the pertinent parameters on various flow distributions is elaborately discussed with the help of graphs and tables. The comparison of present results with the existing literature gave an excellent agreement for the reduced cases.

The Effects of Innovative Shotgun Shooting Methods on Collegiate Shotgun Shooters

Sporting activities are classified according to movement demands and can be categorized as either dynamic or static actions. Many events exist within the discipline of “shooting sports”, and dynamic and static demands vary drastically among those events. However, consideration for differences in movement demands is frequently disregarded in shooting sports; common practice protocol encourages sh ooters to utilize static&#x0D; shooting techniques for all shooting sport events. In particular, shooting techniques for shotgun shooting, a&#x0D; dynamic sporting event, regularly align with rifle shooting (static activity) methods. Innovative dynamic shotgun&#x0D; shoot ing techniques have recently been developed, however, no previous studies have examined the outcomes of employing these dynamic techniques. Therefore, the current research investigated the effects of innovative&#x0D; shotgun shooting methods on collegiate shotg un shooters (n=38). Pre and post trap and skeet scores were&#x0D; collected at a certified International Shooting Sport Federation and USA Shooting competition field. Upon&#x0D; completion of pre-test shooting, subjects participated in an Optimum Shooting Performance (OSP) intervention&#x0D; that outlined innovative dynamic shooting and practice techniques. Post-test shooting scores were collected after2-weeks of OSP practice. A paired sample t test identified statistically significant improvements for trap shootingscores (t[32] = 2.82, p = .008, 95% CI [0.431, 2.660], d = .49),skeet shooting scores (t[32] = 2.59, p = .01, 95% CI[0.436, 3.625], d = .45), and total shooting (sum score of trap and skeet tests) scores (t[32] = 3.37, p = .002, 95%CI [1.417, 5.734], d = .59). These results suggest that learning and utilizing the OSP methods significantly&#x0D; increased the shooting performance of college shotgun shooters.