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Technical Paper

“SODART” Telescope Silicon Detector Cooling System (Thermal Test Results of the Scale-Down Model)

1992-07-01
921365
The onboard “SODART” telescope silicon detector cooling system of the “Spectrum-X-Gamma” observatory, which is designed for the space objects X-ray radiation study, is described. The scale-down model of the passive cooling system description and thermal vacuum test results of this model are given. In the real cooling system the minimal detector temperature at 300 mW heat release is expected about 107 K.
Technical Paper

β-Carotene Content of Dehydrated Hydroponic Sweetpotatoes Grown under Different Lighting Conditions

2007-07-09
2007-01-3051
The sweetpotato (Ipomoea batatas L. LAM.) is a versatile and underexploited food crop. Consumption of sweetpotato based processed foods provide β-carotene, which is the major precursor of vitamin A. The sweetpotato has the potential to provide antioxidants that may help reduce the radiation risks astronauts face while in space. Therefore the objective of this experiment was to evaluate β-carotene in dehydrated hydroponic sweetpotato cultivars. Hydroponic cultivars WHATLEY/LORETAN and NCC-58 were grown with and without 7-10 μmole of light. WHATLEY/LORETAN contained the highest amount of β-carotene content average of 31 μg/100g in dehydrated hydroponic sweetpotatoes compared to NCC-58 with 18.5 μg/100g.
Technical Paper

µMist® - The next generation fuel injection system: Improved atomisation and combustion for port-fuel-injected engines

2011-08-30
2011-01-1890
The Swedish Biomimetics 3000's μMist® platform technology has been used to develop a radically new injection system. This prototype system, developed and characterized with support from Lotus, as part of Swedish Biomimetics 3000®'s V₂IO innovation accelerating model, delivers improved combustion efficiency through achieving exceptionally small droplets, at fuel rail pressures far less than conventional GDI systems and as low as PFI systems. The system gives the opportunity to prepare and deliver all of the fuel load for the engine while the intake valves are open and after the exhaust valves have closed, thereby offering the potential to use advanced charge scavenging techniques in PFI engines which have hitherto been restricted to direct-injection engines, and at a lower system cost than a GDI injection system.
Technical Paper

the behavior of Radiation-Resistant ANP TURBINE LUBRICANTS

1959-01-01
590051
RADIATION can produce almost instantaneous failure of modern aircraft lubricants, tests at Southwest Research Institute show. Two types of failures demonstrated are rapid viscosity rise and loss of heat conductivity. Furthermore, it was found that lubricants can become excessively corrosive under high-level radiation. Generally speaking, the better lubricants appeared to improve in performance while marginal ones deteriorated to a greater extent under radiation. When the better lubricants were subjected to static irradiation prior to the deposition test, there was a minor increase in deposition number as the total dose was increased.
Technical Paper

eROSITA Camera Low Temperature Thermal Control

2008-06-29
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

byteflight~A new protocol for safety-critical applications

2000-06-12
2000-05-0220
The permanently increasing number of convenience and safety functions leads to higher complexity of in-car electronics and the rapidly growing amount of sensors, actuators and electronic control units places higher demands on high- speed data communication protocols. Safety-critical systems need deterministic protocols with fault-tolerant behavior. The need for on-board diagnosis calls for flexible use of bandwidth and an ever-increasing number of functions necessitates a flexible means of extending the system. None of the communication solutions available on the market until now (like CAN or TTP) have been able to fulfill all these demands. To solve these problems, BMW together with several semiconductor companies has developed a new protocol for safety-critical applications in automotive vehicles.
Technical Paper

Zone of Influence of Porous Suction Tubes in Condensing Heat Exchanger for Space Systems

2008-06-29
2008-01-2075
A “next generation” condensing heat exchanger for space systems has to satisfy demanding operational requirements under variable thermal and moisture loads and reduced gravity conditions. Mathematical models described here are used to investigate transient behavior of wetting and de-wetting dynamics in the binary porous system of porous tubes and porous cold plate. The model is based on the Richard's equation simplified for the zero-gravity conditions. The half-saturation distance or the zone of influence of the porous annular suction tubes on the cold-plate porous material will be in the range of 1 to 10 cm for the time scales ranging from 100 to 10,000 seconds and moisture diffusivity in the range of D = 10-4 to 10-6 m2/s.
Technical Paper

Zero-Offset in Transducer Output

2005-05-16
2005-01-2555
Zero-offset in transducer output during airbag noise testing is often observed, but mostly ignored due to the lack of understanding of its causes and implications. In the field of high-g acceleration measurement, this phenomenon is well documented, and is referred to as zeroshift. Zero-offset occurs when a component in the measurement chain is exposed to some unexpected inputs which the component has not been designed to handle. These unexpected inputs can be mechanical, electrical, or optical. How the transducer reacts to such inputs and the amount of zero-offset produced depends on the sensing mechanism, material used, and the design of the component itself. This paper explores the causes of zero-offset from a general perspective, covering the entire measurement chain. Although much of the information and discussions are based on data obtained from acceleration measurement systems, the findings are applicable to other transducer types, such as pressure and acoustic measurements.
Technical Paper

Z-type Schlieren Setup and its Application to High-Speed Imaging of Gasoline Sprays

2011-08-30
2011-01-1981
Schlieren and shadowgraph imaging have been used for many years to identify refractive index gradients in various applications. For evaporating fuel sprays, these techniques can differentiate the boundary between spray regions and background ambient gases. Valuable information such as the penetration rate, spreading angle, spray structure, and spray pattern can be obtained using schlieren diagnostics. In this study, we present details of a z-type schlieren system setup and its application to port-fuel-injection gasoline sprays. The schlieren high-speed movies were used to obtain time histories of the spray penetration and spreading angle. Later, these global parameters were compared to specifications provided by the injector manufacturer. Also, diagnostic parameters such as the proportion of light cut-off at the focal point and the orientation of knife-edge (schlieren-stop) used to achieve the cut-off were examined.
Technical Paper

You-Are-Here Maps for International Space Station: Approach and Guidelines

2004-07-19
2004-01-2584
Guidelines for designing you-are-here (YAH) maps aboard International Space Station (ISS) are proposed, based on results from previous 3D spatial navigation studies conducted by our research group and colleagues. This paper reviews terrestrial YAH maps, the common errors associated with them, and how to appropriately implement what is known from terrestrial to micro-gravity YAH maps. We conclude with a creative example of an ISS YAH map that utilizes given guidelines and information visualization techniques.
Technical Paper

Yield Mapping with Digital Aerial Color Infrared (CIR) Images

1999-09-14
1999-01-2847
Yield potential was predicted and mapped for three corn fields in Central Illinois, using digital aerial color infrared images. Three methods, namely statistical (regression) modeling, genetic algorithm optimization and artificial neural networks, were used for developing yield models. Two image resolutions of 3 and 6 m/pixel were used for modeling. All the models were trained using July 31 image and tested using images from July 2 and August 31, all from 1998. Among the three models, artificial neural networks gave best performance, with a prediction error less than 30%. The statistical model resulted in prediction errors in the range of 23 to 54%. The lower resolution images resulted in better prediction accuracy compared to resolutions higher than or equal to the yield resolution. Images after pollination resulted in better accuracy compared to images before pollination.
Technical Paper

Yield Mapping of Soybeans and Corn Using GPS

1995-09-01
952112
Data obtained when harvesting with a combine equipped with a yield monitor were used to develop yield maps. A prototype yield monitor was developed that uses a combination of light emitters and receivers mounted in a rectangular frame. The monitor was mounted in the combine in the top of the clean grain elevator. As grain flows through the monitor, a voltage change proportional to light reduction was recorded. This voltage was then correlated to grain flow rate. At the same time, site-specific location was recorded using the global positioning satellites (GPS) system. The location data, yield monitor output, cutting width, and combine forward speed were stored in a spreadsheet format. The data were then used to prepare the yield maps.
Technical Paper

Yellowing in Automotive Clearcoats

2016-04-05
2016-01-0538
Automotive clearcoats have many purposes, from providing a glossy finish to protecting the underlying paint layers from UV radiation. Yellowing of clearcoats is a natural phenomenon during weathering processes, as well as from extreme baking conditions, due to polymer degradation. However, occasionally yellowing may be caused by unexpected chemical reactions occurring in the clearcoat. These reactions may happen very quickly (within hours or days) or take years to manifest, as other chemicals migrate into the clearcoat. We have investigated one family of these unexpected reactions which occur with certain UV absorbers, as well as how to prevent the reactions from occurring. We found that certain benzotriazole UV absorbers react readily with some common metals, including copper and zinc, provided that the UV absorber is not in its excited state. The conformational change that occurs within the benzotriazole when it absorbs UV radiation effectively inhibits the reaction with metals.
Technical Paper

Xenon Light for Main and Dipped Beam

1998-02-23
980005
Xenon (HID) technology is one of the mile-stones in developing process of car lighting. The first step was to combine this technology with free-form reflector technology. The result was a high performance dipped beam beam-pattern with three times more light output compared to a halogen system. The next step of improvement is “Bi-Xenon”. It makes sense to use the enormous light output of a Xenon light source for two light functions (Main beam and dipped beam) in a single pocket headlamp system. This leads to new lighting performance and design freedom in headlamp technology. In this paper the technological aspects of system realization will be described. New solutions in lighting strategy including modern actuators which handle optical elements to switch between two light functions had to be found.
Technical Paper

XMM-NEWTON Thermal Design and In-orbit Performance

2000-07-10
2000-01-2372
The XMM-NEWTON satellite is the ESA X-ray spaceborne observatory covering the soft X-ray portion of the electromagnetic spectrum. XMM-NEWTON has been put in orbit on December, 10th 1999 by an Ariane 5 single launch. The spacecraft has a conventional thermal design that takes full advantage of the stable environment provided by its high altitude/long period orbit and by the limited variation of solar attitude angles in order to provide a stable platform for the telescope system. The precise geometry and alignment of the telescope system impose strict temperature requirements so that not only temperature gradients have to be kept small but also, and more importantly, time-variations of the gradients have to be minimised. In the paper, the thermal behaviour of the spacecraft as verified by its thermal test programme is compared with the early in-orbit temperature measurements.
Journal Article

X-ray Imaging of Cavitation in Diesel Injectors

2014-04-01
2014-01-1404
Cavitation plays a significant role in high pressure diesel injectors. However, cavitation is difficult to measure under realistic conditions. X-ray phase contrast imaging has been used in the past to study the internal geometry of fuel injectors and the structure of diesel sprays. In this paper we extend the technique to make in-situ measurements of cavitation inside unmodified diesel injectors at pressures of up to 1200 bar through the steel nozzle wall. A cerium contrast agent was added to a diesel surrogate, and the changes in x-ray intensity caused by changes in the fluid density due to cavitation were measured. Without the need to modify the injector for optical access, realistic injection and ambient pressures can be obtained and the effects of realistic nozzle geometries can be investigated. A range of single and multi-hole injectors were studied, both sharp-edged and hydro-ground. Cavitation was observed to increase with higher rail pressures.
Technical Paper

X-Ray Computed Tomography for Verification of Rivet Installation Assessment Techniques

1998-09-15
982140
High quality rivet installation is of critical importance to the aerospace industry, and the existence of gaps between the rivet head and the countersink is undesirable. Detection of gaps traditionally involves sectioning through rivet joints. Two concerns exist for this method of evaluation: it provides data only from the sectioned plane, and it has potential to alter the gaps. X-ray computed tomography (CT) was used to validate the effectiveness of the tradition sectioning method. It was revealed that the sectioning process generally increased the size of gaps. CT images also revealed that the gaps are not necessarily uniform around the rivet.
Technical Paper

Workspace Analysis and Visualization for Santos'™ Upper Extremity

2005-06-14
2005-01-2739
Workspace is an important function for human factors analysis and is widely applied in product design, manufacturing, and ergonomics evaluations. This paper presents the workspace analysis and visualization for Santos™ upper extremity, a new virtual human with over 100 DOFs that is highly realistic in terms of appearance, behavior, and movement. Jacobian Rank deficiency method is implemented to determine the singular surfaces. The joint limits are considered in this formulation; three types of singularities are analyzed. This closed-form formulation can be extended to numerous different scenarios such as different percentiles, age groups, or segments of body. A realtime scheme is used to build the workspace library for Santos™ that will study the boundary surfaces off-line and apply them to Santos™ in the virtual environment (Virtools®). To visualize the workspace, we develop a user interface to generate the cross section of the reach envelope with a plane.
Standard

Wire and Cable Marking Process, UV Laser

2018-01-18
WIP
AS5649A
This standard is applicable to the marking of aerospace vehicle electrical wires and cables using ultraviolet (UV) lasers. This standard specifies the process requirements for the implementation of UV laser marking of aerospace electrical wire and cable and fiber optic cable to achieve an acceptable quality mark using equipment designed for UV laser marking of identification codes on aerospace wire and cable. Wiring specified as UV laser markable subject to AS4373 Test Methods for Insulated Electric Wire and which has been marked in accordance with this standard will conform to the requirements of AS50881.
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