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Thrust vectoring innovations are demonstrated ideas that improve the projection of aerospace power with enhanced maneuverability, control effectiveness, survivability, performance, and stealth. Thrust vector control systems following a variety of concepts have been considered for modern aircraft and missiles to enhance their military performance. Short Take-off and Landing (STOL) and control effectiveness at lower aircraft speeds can be achieved by employing Fluidic Thrust Vectoring Control (FTVC). This paper summarizes a range of ideas for FTVC that have been designed and tested both computationally and experimentally to determine the thrust vectoring performance of supersonic propulsion system nozzles. The conventional method of thrust vectoring involves mechanical means to deflect the direction of flow of the exhaust gases, whereas the most recent method involves fluidic-based thrust vectoring techniques. Fluid-based thrust vectoring has the advantages of simplicity and low weight over mechanical-based thrust vectoring, which has complex geometry and adds extra weight to the aircraft. The fluidic vectoring control nozzles are divided into seven categories: shock vector, bypass shock vector, counterflow, co-flow, throat skewing, dual throat, and bypass dual throat nozzle control. This paper provides a summary of each fluidic thrust vectoring technique with its characteristics, design, classification, and different operational criteria developed to date and compares the intrinsic characteristics of each technique. Based on the present literature, it is concluded that among all the fluidic control techniques, the bypass dual-throat nozzle control can achieve better thrust vectoring performance with large vector angles and low thrust loss. [ABSTRACT FROM AUTHOR]

Modern aircraft and missiles are gradually integrating thrust vector control systems to enhance their military capabilities. Bypass Dual-Throat Nozzle (BDTN) control is a new fluidic thrust vectoring technique capable of achieving superior performance with large vector angles and low thrust loss. In this study, we analyzed the flow characteristics and performance parameters of BDTN by varying the bypass angle, nozzle convergence angle, and bypass width. The flow governing equations are solved according to a finite volume discretization technique of the compressible RANS equations coupled with the Renormalization Group (RNG) k-ϵ turbulence model for Nozzle Pressure Ratio (NPR = 2~10) to capture the significance of under-expanded and over-expanded jets. Results show that by decreasing the bypass angle from 90° to 35°, there is a 6% increase in vectoring angle while the vectoring efficiency is enhanced by 18%. However, a decrease of 3% in the thrust and discharge coefficients is also observed. When the convergence angle was increased from 22° to 37°, vectoring angle, discharge coefficient, and thrust coefficient increased by 2%, 1%, and 0.26%, respectively. Moreover, vectoring efficiency is also enhanced by 8% by reducing the convergence angle from 37° to 22°. Based on the investigated parameters, it is determined that nozzle convergence angle does not significantly influence thrust vectoring performance, however, bypass width and bypass angle have a significant effect on thrust vectoring performance. [ABSTRACT FROM AUTHOR]

Background: This cross-sectional study investigates the educational background and entry routes of otolaryngology higher surgical trainees in the UK. Method: A survey was disseminated to trainees through training programme directors and 60 responses were received. Results: Most trainees decided to pursue otolaryngology early in their training, with 50 per cent making the decision four or more years before applying for a higher surgical traineeship. Similarly, 68.3 per cent of trainees undertook otolaryngology-themed core surgical training, while two-thirds had an otolaryngology rotation during their foundation training. Most trainees (86.7 per cent) were accepted into core surgical training on their first attempt, and 71.7 per cent gained entry to higher surgical training on their first attempt. Conclusion: The findings highlight the importance of early exposure to otolaryngology and the pursuit of themed core surgical training programmes for building a competitive application. However, unsuccessful first attempts at core surgical training or higher surgical training should not discourage candidates from pursuing a career in otolaryngology. [ABSTRACT FROM AUTHOR]

In this paper, a novel approach has been presented to integrate command to line-of-sight (CLOS) guidance and proportional navigation (PN) guidance in order to reduce miss distance and to increase the effectiveness of surface to air missiles. Initially a comparison of command to line-of-sight guidance and proportional navigation has been presented. Miss distance, variation of angle-of-attack, normal and lateral accelerations and error of missile flight path from direct line-of-sight have been used as noteworthy criteria for comparison of the two guidance laws. Following this comparison a new approach has been proposed for determining the most suitable guidance gains in order to minimize miss distance and improve accuracy of the missile in delivering the warhead, while using CLOS guidance. This proposed technique is based on constrained nonlinear minimization to optimize the guidance gains. CLOS guidance has a further limitation of significant increase in normal and lateral acceleration demands during the terminal phase of missile flight. Furthermore, at large elevation angles, the required angle-of-attack during the terminal phase increases beyond design specifications. Subsequently, a missile with optical sensors only and following just the CLOS guidance has less likelihood to hit high speed targets beyond 45° in elevation plane. A novel approach has thus been proposed to overcome such limitations of CLOS-only guidance for surface to air missiles. In this approach, an integrated guidance algorithm has been proposed whereby the initial guidance law during rocket motor burnout phase remains CLOS, whereas immediately after this phase, the guidance law is automatically switched to PN guidance. This integrated approach has not only resulted in slight increase in range of the missile but also has significantly improved its likelihood to hit targets beyond 30 degrees in elevation plane, thus successfully overcoming various limitations of CLOS-only guidance approach. Hence, proposing an approach to determine most suitable gains for CLOS guidance and integration of CLOS and PN guidance for enhanced effectiveness and accuracy of surface to air missiles are the two significant contributions of this work. [ABSTRACT FROM AUTHOR]

Detection of pulmonary nodule plays a significant role in the diagnosis of lung cancer in early stage that improves the chances of survival of an individual. In this paper, a computer aided nodule detection method is proposed for the segmentation and detection of challenging nodules like juxtavascular and juxtapleural nodules. Lungs are segmented from computed tomography (CT) images using intensity thresholding; brief analysis of CT image histogram is done to select a suitable threshold value for better segmentation results. Simple morphological closing is used to include juxtapleural nodules in segmented lung regions. K-means clustering is applied for the initial detection and segmentation of potential nodules; shape specific morphological opening is implemented to refine segmentation outcomes. These segmented potential nodules are then divided into six groups on the basis of their thickness and percentage connectivity with lung walls. Grouping not only helped in improving system's efficiency but also reduced computational time, otherwise consumed in calculating and analyzing unnecessary features for all nodules. Different sets of 2D and 3D features are extracted from nodules in each group to eliminate false positives. Small size nodules are differentiated from false positives (FPs) on the basis of their salient features; sensitivity of the system for small nodules is 83.33%. SVM classifier is used for the classification of large nodules, for which the sensitivity of the proposed system is 93.8% applying 10-fold cross-validation. Receiver Operating Characteristic (ROC) curve is used for the analysis of CAD system. Overall sensitivity of the system is 91.65% with 3.19 FPs per case, and accuracy is 96.22%. The system took 3.8 seconds to analyze each image. [ABSTRACT FROM AUTHOR]

This research emphasizes designing a straight-bladed Double-Darrieus hybrid vertical axis wind turbine (VAWT) with a high power coefficient as well as self-starting capability. Computational fluid dynamics analysis was performed using the sliding and dynamic meshing techniques. Various datasets were employed in the design of experiments to determine optimal configurations. A quadratic equation based on a regression model was established, and response surface methodology was applied to determine the accuracy of the model by analysis of variance, goodness of fit, investigation of residuals, and R-squared values. The optimized chord length, number of blades, pitch angle, distance of blades from the central rotating shaft, and rotor height were obtained as 0.547 m, 03, -3.41 deg, 0.789 m, and 1.605 m, respectively. A standard H-rotor Darrieus configuration, comprising symmetric airfoils and existing Darrieus-Savonius hybrid VAWTs were also analyzed for comparison. The positive static torque coefficient at all azimuth angles indicates that the proposed hybrid wind turbine is completely self-starting. The output power of the standard Darrieus configuration is substantially zero below a wind speed of 3.65 m/s, indicating that it is not capable of converting the kinetic energy of the airflow into electrical power below this specified value. On the contrary, the self-starting speed of the proposed hybrid wind turbine is as low as 2.81 m/s with a rated power of 1.522 kW at a wind speed of 7.5 m/s. The capability of the proposed hybrid wind turbine with a better power coefficient and transforming wind energy, even at low wind speeds, extends its utilization for various small to large-scale power projects. The proposed approach enables the determination of the optimum design configuration of a hybrid vertical axis wind turbine, along with a high-fidelity analysis in the early design phase. • An innovative straight-bladed Double-Darrieus hybrid VAWT has been explored. • We emphasize designing a VAWT with a high power coefficient as well as improved self-starting capability. • Geometric parameters of hybrid VAWT have been optimized using DOE techniques. • Computational fluid dynamic analysis was performed by using k- ɛ turbulence model. • The proposed methodology enables to obtain optimum design configuration of hybrid VAWT, along with the high fidelity analysis in the early design phase. [ABSTRACT FROM AUTHOR]