Gust alleviation system to improve ride comfort of light airplanes

System consists of movable auxiliary aerodynamic sensors mounted on fuselage and connected to trailing-edge flaps by rigid mechanical linkages. System achieves alleviation by reducing lift-curve slope of airplane to such a small value that gust-induced angles of attack will result in small changes in lift

Global search algorithm for optimal control

Random-search algorithm employs local and global properties to solve two-point boundary value problem in Pontryagin maximum principle for either fixed or variable end-time problems. Mixed boundary value problem is transformed to an initial value problem. Mapping between initial and terminal values utilizes hybrid computer

Effects of Crust Ingestion on Mixer Pump Performance in Tank

In August 1999, a workshop was held at Pacific Northwest National Laboratory to discuss the effects of crust ingestion on mixer pump performance in Hanford Waste Tank 241-SY-101. The main purpose of the workshop was to evaluate the potential for crust ingestion to degrade mixing and/or damage the mixer pump. The need for a previously determined 12-inch separation between the top of the mixer pump inlet and the crust base was evaluated. Participants included a representative from the pump manufacturer, an internationally known expert in centrifugal pump theory, Hanford scientists and engineers, and operational specialists representing relevant fields of expertise. The workshop focused on developing an understanding of the pump design, addressing the physics of entrainment of solids and gases into the pump, and assessing the effects of solids and gases on pump performance. The major conclusions are summarized as follows: * Entrainment of a moderate amount of solids or gas from the crust should not damage the pump or reduce its lifetime, though mixing effectiveness will be somewhat reduced. * Air binding should not damage the pump. Vibration due to ingestion of gas, solids, and objects potentially could cause radial loads that might reduce the lifetime of bearings and seals. However, significant damage would require extreme conditions not associated with the small bubbles, fine solids, and chunks of relatively weak material typical of the crust. * The inlet duct extension opening, 235 inches from the tank bottom, should be considered the pump inlet, not the small gap at 262 inches. * A suction vortex exists at the inlet of all pumps. The characteristics of the inlet suction vortex in the mixer pump are very hard to predict, but its effects likely extend upward several feet. Because of this, the current 12-inch limit should be replaced with criteria based on actual monitored pump performance. The most obvious criterion (in addition to current operational constraints) is to monitor discharge pressure and cease pump operation if it falls below a predetermined amount. * There are no critically necessary tests to prove pump operability or performance before initiating the transfer and back-dilution sequence

Solid state image sensor research Final technical report

Fifty-element linear arrays of InAs photodiode

Spin tests of a single-engine, high-wing light airplane

The airplane has a relatively steep spin mode (low angle of attack) with a high load factor and high velocity. The airplane recovers almost immediately after any deviation from the prospin control positions, except for one maneuver with reduced flexibility in the elevator control system

Computer graphics application in the engineering design integration system

The computer graphics aspect of the Engineering Design Integration (EDIN) system and its application to design problems were discussed. Three basic types of computer graphics may be used with the EDIN system for the evaluation of aerospace vehicles preliminary designs: offline graphics systems using vellum-inking or photographic processes, online graphics systems characterized by direct coupled low cost storage tube terminals with limited interactive capabilities, and a minicomputer based refresh terminal offering highly interactive capabilities. The offline line systems are characterized by high quality (resolution better than 0.254 mm) and slow turnaround (one to four days). The online systems are characterized by low cost, instant visualization of the computer results, slow line speed (300 BAUD), poor hard copy, and the early limitations on vector graphic input capabilities. The recent acquisition of the Adage 330 Graphic Display system has greatly enhanced the potential for interactive computer aided design

Relationship between resistivity and specific heat in a canonical non-magnetic heavy fermion alloy system: UPt_5-xAu_x

UPt_(5-x)Au_x alloys form in a single crystal structure, cubic AuBe_5-type, over a wide range of concentrations from x = 0 to at least x = 2.5. All investigated alloys, with an exception for x = 2.5, were non-magnetic. Their electronic specific heat coefficient $\gamma$ varies from about 60 (x = 2) to about 700 mJ/mol K^2 (x = 1). The electrical resistivity for all alloys has a Fermi-liquid-like temperature variation, \rho = \rho_o + AT^2, in the limit of T -> 0 K. The coefficient A is strongly enhanced in the heavy-fermion regime in comparison with normal and transition metals. It changes from about 0.01 (x = 0) to over 2 micro-ohm cm/K^2 (x = 1). A/\gamma^2, which has been postulated to have a universal value for heavy-fermions, varies from about 10^-6 (x = 0, 0.5) to 10^-5 micro-ohm cm (mol K/mJ)^2 (x > 1.1), thus from a value typical of transition metals to that found for some other heavy-fermion metals. This ratio is unaffected, or only weakly affected, by chemical or crystallographic disorder. It correlates with the paramagnetic Curie-Weiss temperature of the high temperature magnetic susceptibility.Comment: 5 pages, 5 eps figures, RevTe

Case fatality of patients with stroke over a 12-month period post stroke

Introduction. Stroke is among the top 4 causes of death in SouthAfrica and the top 10 leading causes of disability worldwide. There is a dearth of literature on stroke incidence, prevalence and outcome in sub-Saharan Africa. We aimed to establish the case fatality of stroke patients over a 12-month period post discharge from hospital.Methods. A total of 200 patients with first-time ischaemic stroke were recruited from Chris Hani Baragwanath Academic Hospital and followed up for 12 months. The Barthel Index (BI) and Rivermead Mobility Index (RMI) were used to establish patient functional ability and, by inference, stroke severity. Follow-up assessments were performed at 3, 6 and 12 months post discharge. Data analysis was largely descriptive in nature.Results. Thirty-eight per cent of patients died within the 12 month follow-up period; 25.5% within 3 months of discharge. The average length of hospital stay was 6 days. Low BI scores at discharge were observed in the majority of patients who died.Conclusion. The 12-month cumulative mortality was high (highest at the 3-month follow-up). The short hospital stay and poor functional ability of the patients post stroke possibly left them vulnerable to bed-rest complications, such as chest infections and pressure sores

A New Framework for Condominium Structural Safety Reforms

Forty years after the widespread popularization of residential condominium ownership in the United States, millions of Americans now live in aging, densely occupied structures that are subject to little (if any) ongoing regulation of structural safety. Most structural safety requirements are imposed and enforced at the time of initial construction, thus relegating questions of how to maintain a building’s structural integrity to individual owners and the mechanisms of condominium governance. However, reliance on voluntary action by unit owners too often falters because the divided ownership characteristic of the condominium form deters associations from investing in preventive maintenance. Postponement of critical repairs is especially likely when structural safety risks are neither visibly apparent nor easily understood without structural engineering expertise. But tragically, the failure to address structural deterioration can be a deadly mistake, as demonstrated by the 2021 collapse of Champlain Towers South in Surfside, Florida. This Article tackles the problem of structural deterioration in the large and growing stock of aging residential condominiums. It argues that building codes should be reformed to mandate periodic structural safety certifications, while also recognizing that regulation alone may be insufficient to ensure completion of expensive structural repairs when individual owners are unwilling or unable to pay for them. After explaining how property law’s prioritization of liens impedes condominium associations from developing innovative strategies for financing critical structural repairs, the Article proposes reforms that would incentivize the development of a debt market to enable associations to finance those repairs while allowing cash-strapped owners to remain in their homes