A computational investigation was conducted to optimize the fluidic injection angle effects on thrust vectoring. Numerical simulation of fluidic injection for shock vector control, with a convergent-divergent nozzle concept was performed, using URANS approach with Spalart-Allmaras turbulence model. The fluidic injection angles from 60º to 120º were investigated at different aerodynamic and geometric conditions. The current investigation demonstrated that secondary injection angle is an essential parameter in fluidic thrust vectoring. Computational results indicated that, optimizing secondary injection angle would have positive impact on thrust vectoring performance. Furthermore, in most cases, decreasing expansion ratio of the nozzle with increasing NPR has negative impact on pitch thrust vector angle and thrust vectoring efficiency. That is, the highest pitch thrust vector angle is obtained by decreasing nozzle expansion ratio with increasing SPR in smaller fluidic injection angles. In addition, the current investigation attempted to initiate a database of optimized injection angles with different essential parameter effects on thrust vectoring, in order to guide the design and development of an efficient propulsion system.

Background: Lumbar back pain is a common disease, which reduces life quality. Caudal epidural steroid injection (CESI) is frequentlypreferred to relieve lumbar back pain. However, various major complications can be observed due to CESI. A new techniqueof needle angle should be improved to prevent complications such as intraosseous, intrathecal or intravascular injection duringCESI. Objectives: Caudal epidural steroid injection is one of the methods frequently used to treat chronic lumbar back pain. The currentstudy aimed at examining the anatomy of the sacral hiatus and determining the Optimal angle of the needle for CESI. Methods: The current clinical trial was performed in Diyarbakı r Selahaddin Eyyü bi State Hospital from January to June in 2017. Thestudy included 150 adult patients (first group = 92 males (%61. 3), second group = 58 females (%38. 7) aged 18-78 years applied to theAlgology Polyclinic with ASA-PS classes I and II (the American Society of Anesthesiologists (ASA) physical status classification system). Measurements were taken during the CESI applied under ultrasonography (USG) guidance of the intercornual distance, the sacralspace, and the Optimal needle entry angle. Results: The intercornual distance was significantly higher in group one (mean standard deviation (SD): 16. 6 2. 04) than grouptwo (mean SD: 15. 8 2. 51) (P < 0. 049). No difference was observed between group one (mean SD: 4. 49 0. 75) and group two(mean SD: 4. 45 0. 88) with respect to sacral space (P > 0. 79). The most appropriate entry angle for the needle in the applicationof CESI was mean 71. 04° in the whole patient group, as 71. 9° in group one and 69. 7° in group two. There was no significant differencebetween the genders in terms of themeanOptimal angle (P> 0. 091). Also, nosignificant difference was observedamongthe patientsin terms of the demographic data (P > 0. 05). Conclusions: The results of the current study revealed that the Optimal needle angle for CESI applied under USG guidance was71. 04° , different from traditional method and the injection procedure could be safely made directly to the epidural space withoutchanging the angle after entry of the needle to the epidural space.

The present study attempted to utilize a computational investigation to optimize the external freestream flow influence on thrust-vector control. The external flow with different Mach numbers from 0. 05 to 1. 1 and with optimum injection angles from 60° to 120° were studied at variable flow conditions. Simulation of a converging-diverging nozzle with shock-vector control method was performed, using the unsteady Reynoldsaveraged Navier-Stokes approach with Spalart-Allmaras turbulence model. This research established that freestream flow and fluidic-injection angle are the significant parameters on shock-vector control performance. Computational results indicate that, increasing freestream Mach number would decline the thrust vectoring effectiveness. Also, optimizing injection angle would reduce the negative effect of external freestream flow on thrust-vector control. Moreover, increasing secondary to primary total pressure ratios and decreasing nozzle pressure ratios at different freestream Mach number would decrease dynamic response of starting thrust-vector control. Additionally, to lead the improvement of the next generation of jet engine concepts, the current study aimed to originate a database of variable external flow with effective aerodynamic parameters, which have influence on fluidic thrust-vector control.

Purpose: The aim of this study is to evaluate the effectiveness of intraoperative botulinum toxin-A (BTA) injection as an adjunct to the surgical treatment of large-angle esotropia or exotropia.Methods: Thirteen patients were included in this interventional case series study. Mean age of the patients was 23.31±13.29 years (range: 5-43 years). Of these 13 patients, 6 were exotropic and 7 were esotropic. The average preoperative esodeviation was 79.29±16.44 prism diopters (PD) (range: 60-100 PD) and exodeviation was 75.83±11.14 PD (range: 65-90 PD). Depending on the degree of deviation ten or twenty units of Dysport were injected intraoperatively into the recessed horizontal rectus muscles in all of the patients.Results: The average follow-up was 7±1 months (range: 6-8 months). The average final deviation in the esotropia group was 8.57±10.69 PD of esotropia. The average final deviation in the exotropia group was 14.17±12.00 PD of exotropia. The final deviation of the 69% patients was within 15 PD of esotropia or exotropia.Conclusion: This study shows that the combination of BTA injection with recession may be a useful treatment option in cases of large angle horizontal deviation.