Flight test results for a separate surface stability augmented Beech model 99

A flight evaluation of a Beech model 99 equipped with an attitude command control system incorporating separate surface stability augmentation (SSSA) was conducted to determine whether an attitude command control system could be implemented using separate surface controls, and to determine whether the handling and ride qualities of the aircraft were improved by the SSSA attitude command system. The results of the program revealed that SSSA is a viable approach to implementing attitude command and also that SSSA has the capability of performing less demanding augmentation tasks such as yaw damping, wing leveling, and pitch damping. The program also revealed that attitude command did improve the pilot rating and ride qualities of the airplane while flying an IFR mission in turbulence. Some disadvantages of the system included the necessity of holding aileron force in a banked turn and excessive stiffness in the pitch axis

Imkerervaringen : zwermen

Vanzelfsprekend, ga je vaak even kijken hoe het er op je bijenstand aan toe gaat. Na het begin van april staan er nu drie kasten, boordevol met bijen. Hoe warmer het wordt, hoe drukker ook. De hele lucht vóór je kasten en bóven je bijenstand is vol met zoemende beestjes. Prachtig is dat

Cross-Cultural Measurement Invariance in the Personality Inventory for DSM-5

The validity of cross-cultural comparisons of test scores requires that scores have the same meaning across cultures, which is usually tested by checking the invariance of the measurement model across groups. In the last decade, a large number of studies were conducted to verify the equivalence across cultures of the dimensional Alternative Model of Personality Disorders (DSM-5 Section III). These studies have provided information on configural invariance (i.e., the facets that compose the domains are the same) and metric invariance (i.e., facet-domain relationships are equal across groups), but not on the stricter scalar invariance (i.e., the baseline levels of the facets are the same), which is a prerequisite for meaningfully comparing group means. The present study aims to address this gap. The Personality Inventory for DSM-5 (PID-5) was administered to five samples differing on country and language (Belgium, Catalonia, France, Spain, and Switzerland), with a total of 4,380 participants. Configural and metric invariance were supported, denoting that the model structure was stable across samples. Partial scalar invariance was supported, being minimal the influence of non-invariant facets. This allowed cross-cultural mean comparisons. Results are discussed in light of the sample composition and a possible impact of culture on development of psychopathologyPreparation of this manuscript was supported by Grant PSI2017–85022-P (Ministerio de Ciencia, Innovacion ´ y Universidades, Spain) and the UAM-IIC Chair "Psychometric Models and Applications

A Conceptual Aerospace Vehicle Structural System Modeling, Analysis and Design Process

A process for aerospace structural concept analysis and design is presented, with examples of a blended-wing-body fuselage, a multi-bubble fuselage concept, a notional crew exploration vehicle, and a high altitude long endurance aircraft. Aerospace vehicle structures must withstand all anticipated mission loads, yet must be designed to have optimal structural weight with the required safety margins. For a viable systems study of advanced concepts, these conflicting requirements must be imposed and analyzed early in the conceptual design cycle, preferably with a high degree of fidelity. In this design process, integrated multidisciplinary analysis tools are used in a collaborative engineering environment. First, parametric solid and surface models including the internal structural layout are developed for detailed finite element analyses. Multiple design scenarios are generated for analyzing several structural configurations and material alternatives. The structural stress, deflection, strain, and margins of safety distributions are visualized and the design is improved. Over several design cycles, the refined vehicle parts and assembly models are generated. The accumulated design data is used for the structural mass comparison and concept ranking. The present application focus on the blended-wing-body vehicle structure and advanced composite material are also discussed

Study on a camber adaptive winglet

Morphing structures are devices intended to be implemented in specific parts of the aircraft such to improve some aspects of the flight such as performance and maneuverability. More specifically for the wings, the in flight capability of adaptation of airfoil profile and control surfaces bring possibility to the aircraft operate at optimum performance condition during all flight phases. Morphing structures can only lead to optimal flight maneuverability and performance conditions if the morphed geometry leads to an improved flight condition. Aiming at the reduction of the lift induced drag in all flight phases, this research focus on the application of the genetic optimization algorithm for the definition of the camber section of an winglet. This research proposes the optimization at four different flight phases namely: climb, heavy cruise, mid cruise and light cruise. BLWF – a full potential equation solver coupled with 3D boundary layer modelling – is adopted in the aerodynamic performance, e.g. lift and drag ratio, calculation. A conventional genetic algorithm is adopted in the optimization of the camber of the airfoil composing the winglet. This paper describes the optimization procedure and compares geometries showing that the in flight change of the winglet geometry can sensibly contribute to the improvement of the aircraft performance reducing the fuel consumption

Concept of a Maneuvering Load Control System and Effect on the Fatigue Life Extension

Abstract This paper presents a methodology for the conceptual design of a Maneuver Load Control system taking into account the airframe flexibility. The system, when switched on, is able to minimize the bending moment augmentation at a wing station near the wing root during an unsteady longitudinal maneuver. The reduction of the incremental wing bending moment due to maneuvers can lead to benefits such as improved pay-loads/gross weight capabilities and/or extended structural fatigue life. The maneuver is performed by following a desired vertical load factor law with elevators deflections, starting from the trim equilibrium in level flight. The system observes load factor and structural bending through accelerometers and calibrated strain sensors and then sends signals to a computer that symmetrically actuates ailerons for reducing the structural bending and elevators for compensating the perturbation to the longitudinal equilibrium. The major limit of this kind of systems appears when it has to be installed on commercial transport aircraft for reduced OEW or augmented wing aspect-ratio. In this case extensive RAMS analyses and high redundancy of the MLC related sub-systems are required by the Certification Authority. Otherwise the structural design must be performed at system off. Thus the unique actual benefit to be gained from the adoption of a MLC system on a commercial transport is the fatigue life extension. An application to a business aircraft responding to the EASA Certification Specifications, Part 25, has been performed. The aircraft used for the numerical application is considered only as a test case-study. Most of design and analysis considerations are applicable also to other aircraft, such as unmanned or military ones, although some design requirements can be clearly different. The estimation of the fatigue life extension of a structural joint (wing lower skin-stringer), located close to the wing root, has been estimated by showing the expected benefit to be gained from the adoption of such a maneuvering load control system

Effect of brown and green seaweeds on diet digestibility, ruminal fermentation patterns and enteric methane emissions using the rumen simulation technique

Inclusion of the red seaweed Asparagopsis taxiformis as a feed additive, has led to significant reductions in methane (CH4) production from ruminants. However, dietary supplementation with this seaweed is negatively associated with health and environmental concerns mainly due to its bromoform content, a compound with potential carcinogenic properties. Thus, there is renewed focus on ascertaining the anti-methanogenic potential of locally grown brown and green seaweeds, which typically do not contain bromoform. The objective of this study was to investigate the effects of selected brown and green seaweeds on diet digestibility, ruminal fermentation patterns, total gas (TGP) and CH4 production in vitro, using the rumen simulation technique system. In experiment 1, Pelvetia canaliculata (PEC) was examined. In experiment 2, Cystoseira tamariscifolia (CYT), Bifurcaria bifurcata (BIB), Fucus vesiculosus (FUV), Himanthalia elongata (HIM) and Ulva intestinalis (ULI) were analysed. Ascophyllum nodosum (ASC) was included in both experiments. A diet containing A. taxiformis (ASP1; ASP2) and an unsupplemented diet (CON) were included as positive and negative controls, respectively in both experiments. All seaweeds were included at a rate of 10 g/kg dry matter (DM) into a control diet of 50:50 (w:w) forage:concentrate. The seven brown and green seaweeds assessed failed to affect absolute CH4 emissions or alter fermentation patterns. In experiment 1, seaweed treatment had no effect on diet digestibility, CH4%, CH4 mmol/d or CH4 L/d (P>0.1), however ASP1 reduced CH4 mmol/g DOM by 49% (P<0.01) relative to the control. Both ASC and ASP1 tended to increase TGP (P<0.1) relative to the control. In addition to this, the inclusion of seaweed in experiment 1 reduced the production of NH3-N (P<.0001) compared to the control. In experiment 2, seaweed treatment had no effect on diet digestibility or TGP. Both ASP2 and FUV reduced CH4% (P<0.01) but only ASP2 significantly reduced CH4 mmol/d, CH4 L/d and CH4 mmol/g DOM (P<0.05). Daily mMol butyrate was reduced by ASP2 relative to the control and most other seaweeds (P<.0001). In both experiment 1 and 2, seaweed inclusion had no effect on daily total VFA, acetate or propionate production or the acetate:propionate ratio relative to the control. To conclude, including the bromoform-free brown and green seaweeds at 10g/kg DM has no negative effects on diet digestibility or fermentation patterns but also failed to reduce the production of enteric CH4in vitro

Conceptual design of a fifth generation unmanned strike fighter

Unmanned aircraft have significantly transformed aerial warfare through a combination of new technologies, extended operational capabilities, and reduced risks and costs. Similarly, computational modelling techniques have accelerated the rate of development for aircraft by being able to explore a large number of design options from the earliest design stages, further reducing time, risks, and costs. The near future will see the proliferation of unmanned combat aerial vehicles under a variety of roles such as unmanned tankers, strike aircraft, and even air - to - air fighters. In this paper the GENUS aircraft design framework is used to develop an unmanned weapons carrying platform able to partially match the performance of 5th generation fighters such as the Joint Strike Fighter F-35A. The vision of future joint operations is for a single lead manned fighter to command and designate targets to its various loyal wingmen unmanned aircraft, extending the combat capabilities and significantly multiplying force and air superiority

Combined Aerostructural Wing and High-Lift System Optimization

A coupled-adjoint aerostrutctural wing optimization tool has been modified to include the optimization of high-lift devices from the start of the optimization process. The aerostructural tool couples a quasi-three-dimensional method with a finite beam element model. In this paper, the quasi-three-dimensional method is modified using a α method of Van Dam to enable high-lift aerodynamic analysis..

Obesity is not associated with disease-free interval, melanoma-specific survival, or overall survival in patients with clinical stage IB-II melanoma after SLNB

BACKGROUND AND OBJECTIVES: Clinicopathologic characteristics have prognostic value in clinical stage IB‐II patients with melanoma. Little is known about the prognostic value of obesity that has been associated with an increased risk for several cancer types and worsened prognosis after diagnosis. This study aims to examine effects of obesity on outcome in patients with clinical stage IB‐II melanoma. METHODS: Prospectively recorded data of patients with clinical stage IB‐II melanoma who underwent sentinel lymph node biopsy (SLNB) between 1995 and 2018 at the University Medical Center of Groningen were collected from medical files and retrospectively analyzed. Cox‐regression analyses were used to determine associations between obesity (body mass index> 30), tumor (location, histology, Breslow‐thickness, ulceration, mitotic rate, SLN‐status) and patient‐related variables (gender, age, and social‐economic‐status [SES]) and disease‐free interval (DFI), melanoma‐specific survival (MSS), and overall survival (OS). RESULTS: Of the 715 patients, 355 (49.7%) were women, median age was 55 (range 18.6‐89) years, 149 (20.8%) were obese. Obesity did not significantly affect DFI (adjusted hazard ratio [HR] = 1.40; 95% confidence interval [CI] = 0.98–2.00; p = 0.06), MSS (adjusted HR = 1.48;95%CI = 0.97–2.25; p = 0.07), and OS (adjusted HR = 1.25; 95% CI = 0.85–1.85; p = 0.25). Increased age, arm location, increased Breslow‐thickness, ulceration, increased mitotic rate, and positive SLN‐status were significantly associated with decreased DFI, MSS, and OS. Histology, sex, and SES were not associated. CONCLUSION: Obesity was not associated with DFI, MSS, or OS in patients with clinical stage IB‐II melanoma who underwent SLNB