Aircraft Flap Control System: Proposal of a Simulink Test Bench for Evaluating Innovative Asymmetry Monitoring and Control Techniques

One of the most important requirements in the design of secondary flight control actuation system is the proper limitation of the asymmetry between left and right wing flap surfaces; these asymmetries, that are typically due to mechanical transmission failures, must be timely detected and neutralized in order to guarantee the aircraft safety (especially during takeoff and landing flight phase in which the effects of these asymmetries could generates uncontrollable aircraft attitudes). In particular, when the angular asymmetry exceeds a defined critical value, the flap control system must detect and identify the incoming failure and actuate proper stopping procedures in order to limit this increasing asymmetry; to this purpose, it is necessary to conceive effective control algorithms able to perform an early fault detection avoiding false alarms. In recent applications, the most commonly used architectures employ the reversible actuators with wingtip brakes and centrally located PDU (of a dual motor type for operational reliability) because it is cheaper and more efficient, nevertheless, especially in severe fault conditions (torque shaft break under very high aerodynamic load) could generate unacceptable asymmetries. Therefore the development of enhanced flap actuation systems based on innovative layout or enhanced monitoring and control techniques can improve significantly the operating performances of the secondary flight control systems. In order to evaluate the behaviors of a real flap actuation system, simulating with a proper accuracy its dynamic responses and testing the performances of different monitoring and control algorithms, the authors propose a robust simulation developed in Matlab-Simulink numerical environment. By means the proposed numerical simulation model it is also possible to simulate a wide range of operating conditions (variable aerodynamic load, different mechanical layouts and several hydraulic and mechanical failures), to test new flap control system solutions (alternative architectures, new no-back devices or damping systems) and to evaluate the robustness of the aforesaid asymmetry monitoring techniques

Aeronautical Engineering: A special bibliography with indexes, supplement 74

This special bibliography lists 295 reports, articles, and other documents introduced into the NASA scientific and technical information system in August 1976

Aeronautical Engineering: A continuing bibliography, supplement 120

This bibliography contains abstracts for 297 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1980

MARE-WINT: New Materials and Reliability in Offshore Wind Turbine Technology

renewable; green; energy; environment; law; polic

Outcome Measures of New Technologies in Uveal Melanoma Review from the European Vision Institute Special Interest Focus Group Meeting

Uveal melanoma UM is the most common primary intraocular tumor in adults. New diagnostic procedures and basic science discoveries continue to change our patient management paradigms. A recent meeting of the European Vision Institute EVI special interest focus group was held on Outcome Measures of New Technologies in Uveal Melanoma, addressing the latest advances in UM, starting with genetic developments, then moving on to imaging and treatment of the primary tumor, as well as to investigating the most recent developments in treating metastases, and eventually taking care of the patient s well being. This review highlights the meeting s presentations in the context of the published literatur

12th EASN International Conference on "Innovation in Aviation & Space for opening New Horizons"

Epoxy resins show a combination of thermal stability, good mechanical performance, and durability, which make these materials suitable for many applications in the Aerospace industry. Different types of curing agents can be utilized for curing epoxy systems. The use of aliphatic amines as curing agent is preferable over the toxic aromatic ones, though their incorporation increases the flammability of the resin. Recently, we have developed different hybrid strategies, where the sol-gel technique has been exploited in combination with two DOPO-based flame retardants and other synergists or the use of humic acid and ammonium polyphosphate to achieve non-dripping V-0 classification in UL 94 vertical flame spread tests, with low phosphorous loadings (e.g., 1-2 wt%). These strategies improved the flame retardancy of the epoxy matrix, without any detrimental impact on the mechanical and thermal properties of the composites. Finally, the formation of a hybrid silica-epoxy network accounted for the establishment of tailored interphases, due to a better dispersion of more polar additives in the hydrophobic resin

Selective primary systemic treatment for operable breast cancer: a randomised trial

Surgical excision has been the method of choice for initial treatment of operable breast cancer, but is limited in its potential to produce cure. Postoperative systemic therapy prolongs survival, but kinetics theory and experimental data suggest it may be more effective if given preoperatively, with the added advantage of leaving the tumour as a marker of treatment progress. Important questions regarding the efficacy of primary systemic treatment (PST), its effects on known prognostic indicators, and its influence on surgical and psychological morbidity remain to be answered. These were addressed in this thesis.171 women aged 27 -69 with operable (T2_31\10.1 M0) breast cancers 31 -85 mm in diameter were randomised over 68 months, 86 to conventional treatment (CONV) and 85 to PST. In CONY, surgery was followed by tamoxifen, except for node -positive premenopausal women who received 6 cycles of cyclophosphamide, methotrexate and 5- fluorouracil. PST was started after tumour oestrogen receptor (ER) measurement. Patients with ERA 9 fmol /mg were treated by goserelin if premenopausal or with tamoxifen if postmenopausal. Response was assessed by weekly examination. Sequential mammography and ultrasound, and serum CA 15 -3 and HMFG2 measurements were studied as alternative means of monitoring response. Non responding patients and all patients with ER<20 fmol /mg were treated with 6 cycles of cyclophosphamide, doxorubicin and prednisolone (CAP). Surgery followed 12 -16 weeks of PST. The first part of the trial included 79 patients with tumours >40 mm, all of whom underwent mastectomy. The second part allowed tumours >30 mm, and breast conservation was an option.The first 79 patients were studied for morbidity. All toxicity was recorded. Psychological morbidity was assessed by means of the Hospital Anxiety and Depression, and the Mental Adjustment to Cancer questionnaires, completed before, during and after treatment. Surgical morbidity was recorded prospectively according to a pre- defined protocol.170 evaluable patients have been followed up for a median of 37 months and have sustained 53 events. No survival difference has emerged. Axillary lymph nodes, ER and tumour response have emerged as independent indicators of prognosis. Systemic therapy produced significant changes in tumour characteristics but post treatment prognostic data was qualitatively similar to conventionally gathered information.Patients experienced increased anxiety during PST, but psychological adjustment was similar after completion of all treatment. Despite longer treatment for PST, quality adjusted survival was identical to that found for CONY. Surgical morbidity was similar for both groups.Ultrasound proved a highly effective method for measuring tumour size and response to primary systemic therapy. Tumour marker levels were generally low and did not reflect response.The present package of primary systemic treatment is a safe and effective method for treating operable breast cancer, does not lead to excess morbidity, and offers the advantages of a response based approach to therapy

Determining risk factors for surgical wound dehiscence: Development and internal validation of a risk assessment tool

Whilst surgical procedures are considered safe, complications such as surgical wound dehiscence (SWD) may occur despite advances in surgical techniques, infection control practices and wound care. A SWD risk assessment tool was developed from identified risk factors based on a review of the literature and a retrospective case control study. A prospective clinical validation of the tool yielded a predictive power of 71% with an interrater reliability of 100%