Research on Erecting Joint and Dynamic Characteristics of Four-Hinge-Point Dual-Drive Missile

In order to improve the quick reaction ability and stability of the missile launching erecting system, the driving mode of the erecting joint is optimized. A four-hinge-point double-driving erecting joint is proposed and the mechanical model is established, the force and time of erecting cylinder are calculated by Matlab, and compared with two kinds of three-hinge-point joint. The results show that the response speed of the four-hinged double-drive erecting joint is fast, the erecting process is fast in the early stage and stable in the later stage, and the elongation and the erecting cylinder force are between two kinds of three-hinged joints, the four-hinge erector can not only combine the advantages of the three-hinge front-mounted and rear-mounted structure, but also realize the aim of compatibility design and improve the rapidity and stability of the missile erector, it can provide an important basis for the structural design of missile launcher.

Dynamic Analysis of Working Device of Excavator under Limit Digging Force

In order to more accurately analyze the dynamic characteristics of the working device of the hydraulic excavator. The load changes on the two digging trajectories were calculated and analyzed by using the limit digging force model and the theoretical digging force model, respectively. The rigid-flexible coupling model of the working device was established in ADAMS. Taking the limit digging force (LDF) and the theoretical digging force (TDF) as the external load of the working device, the dynamic simulation of the hinge force of the working device in the two trajectories was carried out, and the structural strength analysis of the bucket was carried out by using ANSYS. The results show that the tangential force of the LDF is generally larger than that of the TDF, the hinge point force of the working device changes dynamically with the external load of the tooling, and the influence of the LDF on the hinge point force is greater than that of the TDF. When the LDF is taken as the external load, the structural strength of the bucket meets the operational requirements.

The Mobility of Protestant Dissent

Chapter 5 examines the establishment of non-conformist Protestantism in Early Modern Ireland, concentrating principally but not exclusively on Ulster Presbyterianism, by far and away the most significant of these groupings in terms of numbers and permanence within the religious ecology of the island. It demonstrates the almost entirely migrant provenance of these non-conformist communities and the transnational dimension of their ministerial provision. It also examines how traditions of mobility relating to Covenant-swearing and interparochial communion helped to sustain a distinctive religious identity and the manner in which the mobility of largely Scottish migrants provided the vector for the spread of Presbyterianism. The Interregnum proved a hinge point in the establishment of other forms of non-conformist Protestantism, but their importance largely diminished in the course of the Restoration, although a distinctive Irish Quaker community managed to spread in the island during this period.

Numerical analysis of high-lift configurations with oscillating flaps

This study presents two-dimensional aerodynamic investigations of various high-lift configuration settings concerning the deflection angles of droop nose, spoiler and flap in the context of enhancing the high-lift performance by dynamic flap movement. The investigations highlight the impact of a periodically oscillating trailing edge flap on lift, drag and flow separation of the high-lift configuration by numerical simulations. The computations are conducted with regard to the variation of the parameters reduced frequency and the position of the rotational axis. The numerical flow simulations are conducted on a block-structured grid using Reynolds Averaged Navier Stokes simulations employing the shear stress transport $$k-\omega $$ k - ω turbulence model. The feature Dynamic Mesh Motion implements the motion of the oscillating flap. Regarding low-speed wind tunnel testing for a Reynolds number of $$0.5 \times 10^{6}$$ 0.5 × 10 6 the flap movement around a dropped hinge point, which is located outside the flap, offers benefits with regard to additional lift and delayed flow separation at the flap compared to a flap movement around a hinge point, which is located at 15 % of the flap chord length. Flow separation can be suppressed beyond the maximum static flap deflection angle. By means of an oscillating flap around the dropped hinge point, it is possible to reattach a separated flow at the flap and to keep it attached further on. For a Reynolds number of $$20 \times 10^6$$ 20 × 10 6 , reflecting full scale flight conditions, additional lift is generated for both rotational axis positions.

Optimization of hinge point in luffing mechanism of aerial working vehicle based on PSO algorithm

Luffing mechanism is one of the important parts of aerial working vehicle, which plays a decisive role in the overall stability of boom system, the force of luffing cylinder and the force at each hinge point position. In this paper, the five hinge point luffing mechanism of aerial working vehicle is taken as the research object, and the force of its luffing cylinder under dangerous conditions is optimized. By studying the working principle of the boom system and the force analysis of the luffing mechanism, and then establishing the mechanical model, the objective function was optimized based on particle swarm algorithm and Matlab. The optimization results show that the maximum force on the luffing cylinder decreases by 18.9% with the optimized hinge points, which greatly improves the performance of the whole machine and provides a reference for the application of particle swarm optimization in construction machinery.

Mitral annulus disjunction is associated with adverse outcome in patients with Marfan syndrome and Loeys-Dietz syndrome

Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): South-Eastern Norway Regional Health Authority Background Mitral valve prolapse is a common finding in patients with Marfan (MFS) and Loeys-Dietz syndromes (LDS). Mitral annulus disjunction (MAD) is an atrial displacement of the hinge point of the mitral valve that frequently coexists with mitral valve prolapse, but its clinical relevance in connective tissue disorders is unknown. Purpose To explore the association between MAD and severity of mitral valve and aortic disease in patients with MFS and LDS. Methods We included consecutive MFS patients and LDS patients fulfilling established diagnostic criteria. MAD was identified by echocardiography and defined as the distance from the ventricular myocardium to the hinge point of the posterior mitral leaflet (Figure, panel A). Aortic surgery was defined as emergency surgery for aortic dissection or prophylactic aortic surgery for aortic aneurysm. We recorded the need of mitral valve surgery including mitral valve repair or replacement. Results We included 168 patients of whom 103 (61%) had MFS and 65 (39%) had LDS. We identified MAD in 69 (41%) patients. Aortic surgery was performed in 112 (67%) patients (27 dissections and 85 prophylactic interventions). Patients with MAD were younger at the time of aortic surgery than those without MAD (p log rank = 0.02) (Figure, panel B). Patients needing aortic surgery had greater MAD distance (8 [7-10] mm vs. 7 [6-8] mm, p = 0.04). Mitral valve surgery was performed in 12 (7%) patients, more frequently in patients with MAD than in those without (16% vs. 1%, p < 0.001, p log rank < 0.001) (Figure, panel C). Conclusion MAD was frequent and detected in 41% of patients with MFS and LDS. MAD was associated with a more severe disease phenotype including aortic surgery at younger age and frequent need for mitral valve surgery. Screening patients with MFS and LDS for MAD may provide prognostic information and may be relevant in planning surgical interventions. Abstract Figure

The Paley ilioischial limb modification of the Dega osteotomy

BackgroundWe aim to describe a modified Dega osteotomy technique in detail, emphasizing its eventual advantages in comparison to the original Dega osteotomy and ‘San Diego’ modification. We also present our related literature review on various osteotomy techniques.MethodsWe reviewed the radiological indices of 27 dysplastic hips in 25 children with cerebral palsy and developmental dislocation of the hips (9 boys, 16 girls; mean age, 5 years) who underwent a modified Dega osteotomy according to Paley.ResultsComparing the radiological indices results between our patients and those reported by the various authors in the literature, the data are almost identical.ConclusionsThe modified Dega osteotomy is the only technique wherein all two limbs of the triradiate cartilage are true, which becomes a single hinge where the osteotomy turns. Despite the similar results in the radiological indices between our patients and those in the literature, we still consider that the entire triradiate cartilage is a better hinge point for the iliac osteotomy. The difference between the osteotomy adopted in our institution and the modality described by most authors in the literature is that the latter mostly ignore or miss the ischial limb of the triradiate cartilage.

Hinge point fibrosis in athletes is not associated with structural, functional or electrical consequences: a comparison between young and middle-aged elite endurance athletes

Background The health benefits of extensive endurance training have been debated due to the report of myocardial fibrosis (MF), arrhythmias and temporary post-race cardiac impairment in middle-aged and veteran athletes. The extent of these changes is unknown in elite young athletes. Purpose To assess the prevalence of MF and its structural, functional and electrical impact in highly trained young endurance athletes (YA, 15–23 years) as compared to middle-aged athletes (MA, 30–50 years). We hypothesised that MF would be more frequent in MA and associated with more structural, functional and electrical abnormalities. Methods We prospectively assessed 197 YA and 34 MA. All had ECG, maximal oxygen consumption (VO2max) testing, cardiac magnetic resonance imaging (CMR), echocardiography and 24h-holter. Indexed left ventricular and right ventricular end diastolic volume (LVEDVi, RVEDVi), ejection fraction (LVEF, RVEF), left ventricular mass (LVMi), and MF defined as delayed gadolinium enhancement were assessed by CMR. LV and RV free wall strain (LVSL, RVfwSL) were assessed by 2D speckle tracking echocardiography. Ventricular premature beats (VPB) and non-sustained ventricular tachycardia (nsVT) were assessed by 24h-holter. Results YA and MA (18±2 vs 38±5 years [p<0.01]; 78% vs 80% male [p=0.99]) with an elite level of fitness (VO2max 61±8 vs 54±10 mL/min/kg [p<0.01]; % predicted VO2max 150±20 vs 158±30 [p=0.02]) had a large variance in LV and RV remodelling (Figure 1). MF was seen in 28 athletes (12.5%) and more prevalent in MA than in YA (23.5 vs 10.5%, p=0.048). MF was limited to the hinge points in all 8 MA with MF and 17 YA. 3 YA had LV lateral wall subepicardial MF. 27 of 187 (14.4%) male athletes had MF compared to 1 of 50 (2%) female athletes (p=0.01). MF+ MA(A) and YA(B) as well as MF− MA(C) and YA(D) had similar structural remodelling (LVEDVi 110±14 vs 118±14 vs 113±19 vs 110±16 mL/m2; RVEDVi 120±14 vs 128±17 vs 117±19 vs 125±23mL/m2; LVMi 77±11 vs 83±14 vs 81±14 vs 77±15g/m2, p>0.05). LVEF, LVSL and RVSL were similar (59±3 vs 58±5 vs 61±6 vs 58±6%; −18.8±2 vs −18.8±2 vs −19.8±2 vs −19.3±2%; −26.3±2.4 vs −24.4±2.4; −26.3±3 vs −25.8±3.5% respectively, p>0.05). LVEF <50% was seen in 19 (8.2%) athletes (0 [0%] vs [5%] 1 vs 1 [3.8%] vs 17 [9.6%]; p=0.51). RVEF was higher in D compared to C without further differences between groups (54±4 vs 54±6 vs 53±6 vs 57±5, p=0.005). RVEF<45% was seen 21 (9.1%) athletes (0 [0%] vs 1 [5%] vs 0 [0%] vs 20 [11.3%]; p=0.14). Abnormal T-wave inversion was similar (12.5 vs 5 vs 7.4 vs 6.2%, p=0.93) as was the prevalence of >100VPB/24h (12.5 vs 5 vs 11.1 vs 5.1%, p=0.42). 2 athletes had nsVT, both in D. All had similar exercise capacity (% predicted VO2max 157±26 vs 152±15 vs 147±24 vs 158±32%; p=0.11). Conclusion Hinge-point fibrosis was more prevalent in MA, possibly due to repeated hemodynamic stress during exercise, but is not associated with structural, functional or electrical consequences. Figure 1. Cardiac remodelling in elite athletes Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Fonds voor Wetenschappelijk Onderzoek (FWO)