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Technical Paper

“Model Based Predictive Control of MELISSA Photobioreactors. Steady State Determination”

1994-06-01
941411
Mathematical modeling and control of artificial ecosystems, such as MELISSA, require first the study of physical and biological characteristics in optimal and limiting conditions. Following the previous determination of the stoichiometric equations (Spirulina compartment) and regarding the two phototrophic compartments of MELISSA (Rhodospirillaceae and Spirulina), we have first to focus our control study on the growth kinetics for the light source. In this paper, we recall the theoretical equations of microbial growth kinetics and emphasise the problem of the light transfer in a photobioreactor. We present their adaptations to our pilot plant taking into account technological and biological specifics (lamp spectrum, working illuminated volume, growth rate,…). We then develop the principles and structure of the control system and describe tests of both the hardware and software for several steady state configurations.
Technical Paper

“Condensation – Why it Needs to be Addressed in Every Aircraft”

2003-09-08
2003-01-3000
A wide body aircraft carries almost a half–ton of water and ice between the cabin and skin of the aircraft. The water can get on wires and connectors, which can cause electrical problems, cause corrosion and rust, and, eventually, “rain in the plane”. The speaker is the CEO of CTT Systems that has developed a system that solves the condensation by using dry air. The speaker will discuss how condensation can be prevented and how airlines can also save maintenance costs in the process. This topic is relevant for the attendees at the Aerospace Expo, as they are decision makers who need to be aware of this issue. It is also important for the MRO shows as the attendees are on the front lines of dealing with this problem.
Technical Paper

eROSITA Camera Low Temperature Thermal Control

2008-01-29
2008-01-1957
eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is a powerful X-ray telescope under development by the Max-Planck-Institut für extraterrestrische Physik (MPE) in Garching, Germany. eROSITA is the core instrument on the Russian SRG1 mission which is planned for launch in 2011. It comprises seven nested Wolter-I grazing incidence telescopes, each equipped with its own CCD camera. The mirror modules have to be maintained at 20°C while the cameras are operated at -80°C. Both, mirrors and CCDs have to be kept within tight limits. The CCD cooling system consists of passive thermal control components only: two radiators, variable conductance heat pipes (VCHP) and two special thermal storage units. The orbit scenario imposes severe challenges on the thermal control system and also on the attitude control system.
Technical Paper

Zero-G Simulation using Neutral Buoyancy

1989-07-01
891529
For human beings who have been reared on the earth with its 1 G gravitational field, the condition of weightlessness is a world with which we are unfamiliar. Even if the layout and equipment configuration of a spacecraft designed to compensate for operation under Zero-G conditions, there are some things which are not effective under actual weightless conditions. In the design of a manned spacecraft, it is necessary to accumulate design data on human performance in a weightless condition, then to undertake design evaluations and verification under weightless conditions. In this paper, testing for the purpose of evaluating the effectiveness of Zero-G simulation using neutral buoyancy, conducted first of all in Japan, and recommendations on the equipment and Facilities required to conduct such simulations, are described.
Technical Paper

XB-70A Laboratory for Progress

1966-02-01
660276
The development of the XB-70 research aircraft produced advancements in many fields of technology. This paper covers a few of these advancements in the areas of materials, equipment, and manufacturing. These include honeycomb construction, PH 15-7 alloy steel, vacuum melted H-11 steel, equipment capable of withstanding high temperatures, chemical milling of many different alloys, miniaturized welding equipment, and exothermic brazing techniques.
Technical Paper

XB-70 Ground Servicing and Safety Precautions

1966-02-01
660275
Planning for ground servicing and maintenance started in the proposal phase and has been followed by test program experience with the XB-70 Mach 3 air vehicle. Servicing and associated safety requirements are summarized. Discussion of maintenance and support actions includes mention of equipment provided to meet the requirements. Preflight, postflight, and periodic operations are outlined, along with some indication of changes that resulted when plans were put into practice. The demands of a high performance flight test air vehicle limit movements toward simplification.
Technical Paper

X-Ray Rocking Curve Analysis of the Aging and Deformation Characteristics in the Al-Li Alloy

1989-04-01
891057
A non-destructive x-ray technique, the double crystal diffractometer method, is presented as a tool to investigate the aging and deformation behavior of the Al-Li alloy. This is a sensitive method for measuring the strain and dislocation density within individual grains through the x-ray rocking curve. In addition, models were developed to describe the aging and deformation characteristics of this alloy.
Technical Paper

X-Ray - A Necessary Tool for Detecting Incipient Structural Failures in Service Aircraft

1964-01-01
640510
X-ray is an indispensable aid in locating and determining the extent of incipient failures in structure which is inaccessible by position or covered by multiple layers of metal. It is also the most feasible method for checking oil coolers for contamination; bonded honeycomb panels for water; fuel lines for erosion; and with a 360 deg emission tube, fuselage frames for structural integrity without removing the interior upholstery and panels from the passenger compartment or cargo compartments.
Technical Paper

X-29A Subsystems Integration - An Example for Future Aircraft

1988-10-01
881504
The X-29A is the first X-series experimental aircraft developed in the United States since the mid-sixties. The X-29A is a technology demonstrator aircraft that integrates several different-technologies into one airframe. Among the technologies demonstrated are the aeroservoelastically tailored composite forward swept wings, close coupled canards, discrete variable camber wing, triplex digital flight control system with analog backup, thin supercritical wing, three surface pitch control, large negative static margin and the integration of these technologies into the X-29 airframe. This paper deals with the issue of technology integration of five of the X-29A subsystems and the early design decision to use existing aircraft, components whenever and wherever possible. The subsystems described are the X-29 aircraft Hydraulics System, the Electrical Power System, the Emergency Power System, the Aircraft Mounted Accessory Drive and the Environmental Control System.
Standard

Wrenches; Flare Nut, Crowfoot, 6- and 12-Point Non-Distorting

2024-01-22
CURRENT
AS4167D
This SAE Aerospace Standard (AS) covers 6-point and 12-point flare nut crowfoot, flare nut wrenches, double end flare nut wrenches, combination box end and flare nut wrenches, combination open end and flare nut wrenches, and ratcheting flare nut wrenches that are designed with the following requirements: (a) non-distorting usage; (b) possessing the strength, clearances, and internal wrenching design to be used on hydraulic tube fittings that conform to the requirements of SAE J514 and ISO 8434-2; and (c) transmitting torque to tube fittings without bearing on the apex of fitting wrenching points. Inclusion of dimensional data in this document is not intended to imply that all of the products described herein are stock production sizes. Consumers are requested to consult with manufacturers concerning lists of stock production sizes.
Standard

Wrenches, Hand, Twelve Point, High Strength, Thin Wall

2023-03-20
CURRENT
AS954H
This SAE Aerospace Standard (AS) covers high strength thin wall (commercial) sockets, universal sockets, box wrenches and torque adaptors which possess the strength, clearances, and internal wrenching design so configured that, when mated with bi-hexagonal fasteners conforming to the requirements of AS870 for inch sizes and ISO 4095 for metric sizes, they shall transmit torque to the fastener without bearing on the outer 5% of the fastener's wrenching points. Inclusion of dimensional data in this document is not intended to imply that all the products described herein are stock production sizes. Consumers are requested to consult with manufacturers concerning lists of stock production sizes. The dimensional limits of box and combination wrench lengths have been established to provide configuration control for tool storage applications.
Standard

Wrench, Spanner

2021-07-28
CURRENT
AS6018A
This SAE Aerospace Standard (AS) covers adjustable and non-adjustable spanner wrenches generally used for aerospace machinery maintenance and for tightening and loosening hose couplings and hydrant caps. Inclusion of dimensional data in this document is not intended to imply all of the products described therein are stock production sizes. Consumers are requested to consult with manufacturers concerning lists of stock production sizes.
Standard

Worldwide On-Board Diagnostic Requirements Overview

2024-02-28
CURRENT
J3248_202402
This document focuses on the latest in-force regulations. However, in addition to latest information, the report may include historical information. As regulations are superseded, the previous entry will remain to help understand the change in requirements over time. The initial focus of the document includes light-, medium-, and heavy-duty on-road vehicles with all propulsion systems. The document will include information from the United States and Canada, with later publications expanding to other regions. Forecasts for future regulations will not be included in the spreadsheet but be kept in a separate document. The document may be expanded to other types of applications/vehicles as information becomes available.
Technical Paper

Workload and Situation Awareness in Future Aircraft

1987-10-01
871803
Cockpits have changed dramatically over the last ten years. The electro-mechanical instruments have largely been replaced with electro-optical controls and displays. This change in the pilot-vehicle interface, coupled with a second development, the emergence of a very powerful airborne computer system, an Electronic Crewmember, has had a significant impact on workload in the cockpit. Workload has shifted from physical to mental, and many workload measurement tools applied previously may no longer be appropriate. This paper discusses the prediction, real time measurement and dynamic allocation of cockpit workload in an aircraft with a crew of two -- one human and one electronic.
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