The Effect of Propellers and Nacelles on the Landing Speeds of Tractor Monoplanes

This paper reports wind-tunnel tests giving the lift coefficients of large-scale wing-nacelle combinations both with and without the propeller. The tests were made to show the effect of nacelles, and idling and stopped propellers on the landing speeds of tractor monoplanes. Four types of nacelles with various cowlings were used in numerous positions with respect to both a Clark Y and a thick airfoil. The effect of both the idling and stopped propeller on lift, and consequently on landing speed, was negligible. A nacelle with exposed engine cylinders when placed directly in front of an airfoil caused a slight reduction in lift, consequently an increase in landing speed, over the condition with the wing alone. With this exception no appreciable effect on landing speed was indicated for any of the other combinations

Drag Tests of 4/9-Scale Model Engine Nacelles with Various Cowlings

Results are given of drag tests of 4/9-scale model radial air-cooled engine nacelles made as a part of a general investigation of wing-nacelle-propeller interference. A small nacelle of the type commonly used with exposed engine cylinders was tested with various forms of cowling over the cylinders. The effects of cowling-ring position and of angle of ring chord to the thrust line were investigated. An N.A.C.A. cowled nacelle and a smooth body were also tested. The results are given at 50, 75, and 100 miles per hour for -5 degrees, 0 degrees, 5 degrees, 10 degrees, 15 degrees angle of pitch

Wind-tunnel Tests of a Cyclogiro Rotor

During an extensive study of all types of rotating wings, the NACA examined the cyclogiro rotor and made an aerodynamic analysis of that system (reference 1). The examination disclosed that such a machine had sufficient promise to justify an experimental investigation; a model with a diameter and span of 8 feet was therefore constructed and tested in the 20-foot wind tunnel during 1934. The experimental work included tests of the effect of the motion upon the rotor forces during the static-lift and forward-flight conditions at several rotor speeds and the determination of the relations between the forces generated by the rotor and the power required by it

Campesinos pobres y absolutismo reformista

El artículo estudia los conflictos originados a partir de los años `60 del siglo XVIII en dos señoríos bajo-andaluces de la Casa de Osuna (Osuna y Morón de la Frontera), a raíz de la puesta en práctica de las Provisiones del Consejo de Castilla sobre el reparto de las tierras de Propios y Arbitrios. Se parte de una visión del municipio como espacio político dinámico, que funcionaba según sus propias reglas, pero estaba al mismo tiempo integrado en estructuras de poder más amplias -estatales y señoriales- por un complejo entramado de relaciones institucionales y personales. Los casos de Osuna y Morón permiten analizar las posibilidades de los campesinos pobres de acudir a los tribunales reales y exigir el cumplimiento de las medidas de la Corona en su favor. Los campesinos buscaban la protección de vecinos poderosos, quienes por su parte intentaban instrumentalizar la oposición campesina, destacando que en Osuna la Casa ducal intervino protegiendo discretamente a los campesinos pobres.This paper is about the conflicts in two agro-towns of Lower Andalucia (Osuna and Morón de la Frontera) caused by the distribution of communal lands to poor peasants, landless farmers and labourers, which was ordered by the Council of Castile from 1767. The municipalities are described as dynamic and still largely autonomous political units, which are however bound up in complex networks of institutional and personal relationships within the structures of seigneurial jurisdictions and the State. The paper investigates the possibilities which poor peasants had of legally enforcing the ordinances of the Council of Castile against the resistance of the local governments. The peasants tried to use the patronage of the urban elites, the seigneurial administration of the Duke of Osuna or the clergy. They in turn used the peasants' protest movements as an instrument in their own struggle against the local governments

Komplikationen im Rahmen einer temporären, elektrokortikographischen Erfassung von Spreading Depolarizations und deren Beteiligung an unterschiedlichen Hirnpathologien

Einleitung: Patienten mit aneurysmatischer Subarachnoidalblutung (aSAB) entwickeln regelmäßig sekundäre Komplikationen, die den Krankheitsverlauf und –ausgang maßgeblich beeinflussen. Spreading Depolarizations (SDs) sind neuronale Massendepolarisationen, die mutmaßlich zur Entwicklung und Progression ischämischer Läsionen beitragen. Wir untersuchten Komplikationsraten in der Akutphase nach aSAB bei Patienten, denen zur Erfassung von SDs ein Elektrokortikographie-Streifen (ECoG) implantiert wurde. Methodik: 30 Patienten wurden prospektiv in die Studie eingeschlossen und deren Komplikationsraten mit 30 retrospektiv analysierten Kontrollpatienten verglichen, die während des gleichen Zeitraums behandelt, aber nicht mit einem ECoG-Elektrodenstreifen versorgt wurden. Ein Gruppenabgleich erfolgte hinsichtlich des Geschlechts, der Implantation einer externen Ventrikeldrainage sowie einer bekannten Graduierung von aSABs. Ergebnisse: Die Komplikationsraten entsprachen weitgehend denen vergangener Studien ohne ECoG-Streifen. Abweichungen zwischen ECoG- und Kontrollgruppe sind am ehesten auf das Studiendesign zurückzuführen. Über den Vergleich der beiden Gruppen hinaus fiel folgendes auf: Patienten mit initialer intrazerebraler Blutung (ICB) hatten einen signifikant höheren mittleren intrakraniellen Druck (ICP) während der ersten fünf Tage nach aSAB, erhielten höhere Kumulativdosen bestimmter Sedativa, waren länger sediert als Patienten ohne ICB und zeigten eine höhere Rate an Pneumonien. Patienten mit verzögerten zerebralen Ischämien hatten eine höhere Rate an Pneumonien, längere Verweildauer auf der Intensivstation sowie eine stärkere funktionelle Beeinträchtigung an Tag 15 nach aSAB. Patienten, die eine Pneumonie entwickelten, zeigten häufiger Fisher 3-Blutungen, ICBs, verzögerte Infarkte, fokale Hirnläsionen und wiesen einen höheren mittleren ICP sowie eine stärkere Beeinträchtigung an Tag 15 auf. Wir sahen keine Komplikationen im Zusammenhang mit der ECoG-Aufzeichnung, die klinisch relevant waren oder weitere Interventionen erforderten. Insbesondere ergab sich kein Anhalt für lokale Hirngewebsschädigungen oder entzündliche Komplikationen. Schlussfolgerung: SDs konnten bei verschiedenen Hirnpathologien wie aSAB und ischämischen Schlaganfällen nachgewiesen und mit ischämischer Neurodegeneration und einer funktionellen Beeinträchtigung für die Patienten in Zusammenhang gebracht werden. Umso wichtiger erscheint ihre weitere Erforschung mithilfe des klinischen ECoG-Monitorings. Unsere Daten legen nahe, dass eine temporäre Aufzeichnung von SDs mittels ECoG zur Therapiesteuerung sowie weiteren Erforschung von SDs bei aSAB-Patienten mit einem geringen und vertretbaren Risiko für den Patienten verbunden ist.Introduction: Patients with aneurysmal subarachnoid hemorrhage (aSAH) frequently develop secondary complications with an important impact on clinical course and outcome. The term spreading depolarization (SD) describes a wave of neuronal mass-depolarization that presumably contributes to evolution and progression of ischemic lesions in neurological disease. We here report on the rate of complications in patients who received a recording strip for electrocorticographic detection of SDs (ECoG). Methods: 30 patients with severe aSAH were prospectively recruited for the ECoG-study and compared with 30 retrospectively included control patients with aSAH who did not receive an ECoG recording strip. Both groups were matched according to sex, establishment of an external ventricular drainage and a known aSAH grading system. Results: Our results were largely consistent with previous studies. Differences between the ECoG- and control group were likely attributable to the design of the study. Apart from the group comparison, we consider some observations worth mentioning. Patients with initial intracerebral hemorrhage showed significantly higher values of mean intracranial pressure during the first five days following aSAH, received higher cumulative doses of certain sedatives, were sedated for a longer time and showed a higher rate of pneumonia. In patients who developed delayed cerebral ischemia (DCI), the proportion of patients with pneumonia and a prolonged length of stay in the intensive care unit was significantly higher and the patients showed a less favourable outcome on day 15 after aSAH than patients without DCI. Patients with pneumonia showed considerably more Fisher grade 3 and intracerebral hemorrhages, delayed infarctions as well as focal brain lesions, higher values of mean intracranial pressure and significantly more often a less favourable outcome on day 15 after aSAH. There was no evidence for any study-related complications that were clinically relevant or necessitated additional interventions. In particular, we observed no secondary focal brain tissue damage or infectious complications related to the ECoG-study. Conclusions: SDs were shown to occur abundantly in neurological diseases such as ischemic stroke and aSAH. They contribute to ischemic lesion progression and are associated with adverse effects on the functional outcome. Further research on the electrophysiology of SDs and its applicability to potential neuroprotective strategies are needed. Our data suggest that monitoring of SDs using ECoG can be performed temporarily with a very low and justifiable risk for patients with aSAH

The Effect of Lateral Inclination of the Thrust Axis and of Sweepback of the Leading Edge of the Wing on Propulsive and Net Efficiencies of a Wing-Nacelle-Propeller Combination

This report describes and gives the results of tests made to determine the effect of lateral inclination of the propeller thrust axis to the direction of flight. A wing-nacelle-propeller combination with the nacelle axis located successively parallel to and at 15 degrees to the perpendicular to the leading edge of a wing was tested with the combination at several angles of yaw. Tests of the wing alone at the same angles of yaw were also made. The data are presented in the usual graphic form. An increase in propulsive efficiency with increase in angle of the thrust axis was found. The change in net efficiency, found by charging the whole nacelle drag to the power unit, was negligible, however, within the range of the tests

Impact of meal fatty acid composition on postprandial lipaemia, vascular function and blood pressure in postmenopausal women

Cardiovascular diseases (CVD) are the leading cause of death in women globally, with aging associated with progressive endothelial dysfunction and increased CVD risk. Natural menopause is characterised by raised non-fasting triacylglycerol (TAG) concentrations and impairment of vascular function compared with premenopausal women. However, the mechanisms underlying the increased CVD risk after women have transitioned through the menopause are unclear. Dietary fat is an important modifiable risk factor relating to both postprandial lipaemia and vascular reactivity. Meals rich in saturated (SFA) and monounsaturated fatty acids (MUFA) are often associated with greater postprandial TAG responses compared with those containing n-6 polyunsaturated fatty acids (PUFA), but studies comparing their effects on vascular function during the postprandial phase are limited, particularly in postmenopausal women. This review aimed to evaluate the acute effects of test meals rich in SFA, MUFA and n-6 PUFA on postprandial lipaemia, vascular reactivity and other CVD risk factors in postmenopausal women. The systematic literature search identified 778 publications. The impact of fat-rich meals on postprandial lipaemia was reported in seven relevant studies, of which meal fat composition was compared in one study described by three papers. An additional study determined the impact of a high fat meal on vascular reactivity. Although moderately consistent evidence suggests detrimental effects of high fat meals on postprandial lipaemia in postmenopausal (than premenopausal) women, there is insufficient evidence to establish the impact of meals of differing fat composition. Furthermore, there is no robust evidence to conclude the effect of meal fatty acids on vascular function or blood pressure. In conclusion, there is an urgent requirement for suitably powered robust randomised controlled trials to investigate the impact of meal fat composition on postprandial novel and established CVD risk markers in postmenopausal women, an understudied population at increased cardiometabolic risk