Energy Efficient Engine: Control system component performance report

An Energy Efficient Engine (E3) program was established to develop technology for improving the energy efficiency of future commercial transport aircraft engines. As part of this program, General Electric designed and tested a new engine. The design, fabrication, bench and engine testing of the Full Authority Digital Electronic Control (FADEC) system used for controlling the E3 Demonstrator Engine is described. The system design was based on many of the proven concepts and component designs used on the General Electric family of engines. One significant difference is the use of the FADEC in place of hydromechanical computation currently used

Energy Efficient Engine (E3) controls and accessories detail design report

An Energy Efficient Engine program has been established by NASA to develop technology for improving the energy efficiency of future commercial transport aircraft engines. As part of this program, a new turbofan engine was designed. This report describes the fuel and control system for this engine. The system design is based on many of the proven concepts and component designs used on the General Electric CF6 family of engines. One significant difference is the incorporation of digital electronic computation in place of the hydromechanical computation currently used

Control means for a gas turbine engine

A means is provided for developing a signal representative of the actual compressor casing temperature, a second signal representative of compressor inlet gas temperature, and a third signal representative of compressor speed. Another means is provided for receiving the gas temperature and compressor speed signals and developing a schedule output signal which is a representative of a reference casing temperature at which a predetermined compressor blade stabilized clearance is provided. A means is also provided for comparing the actual compressor casing temperature signal and the reference casing temperature signal and developing a clearance control system representative of the difference. The clearance control signal is coupled to a control valve which controls a flow of air to the compressor casing to control the clearance between the compressor blades and the compressor casing. The clearance control signal can be modified to accommodate transient characteristics. Other embodiments are disclosed

Integrated control system for a gas turbine engine

A control system for a turbofan engine receives signals from a number of engine sensors and from the engine operator, and generates control signals. One control signal regulates the fan exhaust nozzle area in order to control inlet throat Mach number to maintain a low level of engine noise. Additional control signals regulate fuel flow to control engine thrust and fan pitch to control fan speed. A number of schedules are utilized to maintain a predetermined relationship between the controlled parameters and a number of fixed and calculated limits can override the control signals to prevent unsatisfactory engine performance

Energy efficient engine: Flight propulsion system preliminary analysis and design

The characteristics of an advanced flight propulsion system (FPS), suitable for introduction in the late 1980's to early 1990's, was more fully defined. It was determined that all goals for efficiency, environmental considerations, and economics could be met or exceeded with the possible exception of NOx emission. In evaluating the FPS, all aspects were considered including component design, performance, weight, initial cost, maintenance cost, engine system integration (including nacelle), and aircraft integration considerations. The current FPS installed specific fuel consumption was reduced 14.2% from that of the CF6-50C reference engine. When integrated into an advanced, subsonic, study transport, the FPS produced a fuel burn savings of 15 to 23% and a direct operating cost reduction of 5 to 12% depending on the mission and study aircraft characteristics relative to the reference engine

Primary central nervous system lymphoma

O linfoma primário do sistema nervoso central (LPSNC) é um linfoma extralinfonodal que, ao diagnóstico, encontra-se restrito ao parênquima cerebral, às meninges e/ou cordão espinhal e/ou olhos. Sua incidência triplicou nas últimas três décadas para 0,4 casos por 100.000 habitantes, representando 4% dos tumores do sistema nervoso central (SNC). Embora pacientes infectados pelo HIV tenham 3.600 vezes maior risco para o desenvolvimento do LPSNC, a incidência não aumentou apenas neste grupo de pessoas. Dados sugerem reduções da incidência de LPSNC em pacientes infectados após a introdução de drogas anti-retrovirais. Cerca de 90% dos casos de LPSNC são classificados como linfoma difuso de grandes células B, 10% têm envolvimento ocular e 10% são HIV positivos. A apresentação clínica depende da localização tumoral, prevalecendo os sintomas neurológicos em detrimento aos sistêmicos. Os exames de tomografia computadorizada (TC) e ressonância nuclear magnética (RNM) são essenciais para o diagnóstico, porém o exame confirmatório deve ser o anatomopatológico. O estadiamento deve ser feito com exames de imagem e biópsia de medula óssea (BMO) bilateral. Os principais fatores de mau prognóstico são: performance status do paciente acima de 1, idade superior a 60 anos, DHL elevada, hiperproteinorraquia e acometimento de área cerebral não hemisférica. Alguns fatores de prognóstico biológicos também podem influenciar na sobrevida, a exemplo da expressão de Bcl-6, que confere melhor prognóstico. O tratamento de escolha é a combinação de quimioterapia contendo altas doses de metotrexate e radioterapia (RDT). Devido às altas taxas de neurotoxicidade associada à RDT, seu uso tem ficado mais restrito aos pacientes idosos, e os recidivados ou refratários.Primary Central Nervous System lymphoma (PCNSL) is an extranodal non-Hodgkin lymphoma in the brain, leptomeninges, spinal cord or eyes. The incidence of PCNSL increased approximately three-fold in the last decades. Nowadays, it represents 0.4 case per 100,000 people and accounts for 4% of all primary brain tumors. Although individuals infected with HIV have a 3,600-fold increased risk of developing PCNSL compared with the general population, the incidence has not increased only in AIDS group. Recent data suggest that the incidence of PCNSL declined in the AIDS group after the introduction of anti-retroviral drugs. Around 90% of PCNSL cases are classified as diffuse large B-cell lymphoma, 10% involve the eyes and 10% of patients are HIV positive. The clinical presentation depends on the location of the tumor with neurological rather than systemic symptoms. Computed tomography (CT) and magnetic resonance imaging (RMI) are essential in diagnosis, however the gold standard is tumor biopsy. Staging should be made with imaging and bilateral biopsy of bone marrow. The main poor prognosic parameters are performance status greater than 1, age older than 60 years, elevated DHL, high liquor protein concentration and tumor located within the deep regions of the brain. BCL-6 expression identified in the tumor confers a better prognosis. Currently, a combined therapy with high doses of methotrexate and whole-brain radiotherapy is the therapy of choice. Nowever, whole-brain radiotherapy should be carefully analyzed because neurotoxity is a frequent problem in the elderly and in relapsed and refractory patients

The use of porcine small intestinal submucosa mesh (SURGISIS) as a pelvic sling in a man and a woman with previous pelvic surgery: two case reports

<p>Abstract</p> <p>Introduction</p> <p>Closing the pelvic peritoneum to prevent the small bowel dropping into the pelvis after surgery for locally recurrent rectal cancer is important to prevent adhesions deep in the pelvis or complications of adjuvant radiotherapy. Achieving this could be difficult because sufficient native tissue is unavailable; we report on the use of small intestine submucosa extra-cellular matrix mesh in the obliteration of the pelvic brim.</p> <p>Case presentation</p> <p>We describe two cases in which submucosa extra-cellular matrix mesh was used to obliterate the pelvic brim following resection of a recurrent rectal tumour; the first patient, a 78-year-old Caucasian man, presented with small bowel obstruction caused by adhesions to a recurrent rectal tumour. The second patient, an 84-year-old Caucasian woman, presented with vaginal discharge caused by an entero-vaginal fistula due to a recurrent rectal tumour.</p> <p>Conclusion</p> <p>We report on the use of submucosa extra-cellular matrix mesh as a pelvic sling in cases where primary closure of the pelvic peritoneum is unfeasible. Its use had no infective complications and added minimal morbidity to the postoperative period. This is an original case report that would be of interest to general and colorectal surgeons.</p