Browse Topic: Vacuum

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Suction Cup Quality Predication by Digital Image Correlation2023-01-00674/11/2023
Vacuum suction cups are used as transforming handles in stamping lines, which are essential in developing automation and mechanization. However, the vacuum suction cup will crack due to fatigue or long-term operation or installation angle, which directly affects production productivity and safety. The better design will help increase the cups' service life. If the location of stress concentration can be predicted, this can prevent the occurrence of cracks in advance and effectively increase the service life. However, the traditional strain measurement technology cannot meet the requirements of tracking large-field stains and precise point tracking simultaneously in the same area, especially for stacking or narrow parts of the suction cups. The application must allow multiple measurements of hidden component strain information in different fields of view, which would add cost. In this study, a unique multi-camera three-dimensional digital image correlation (3D-DIC) system was designed
Guo, Bicheng, Zheng, Xiaowan, Fang, Siyuan, Yang, Lianxiang
A Study on Optimization of Brake Feeling and Method for Flexible Brake with Integrated Electronic Booster2020-01-164210/5/2020
Throughout the automotive industry, the application of an integrated electronic booster (IEB) system has been actively applied following with diversify powertrain types and expand autonomous vehicles.[1, 2] Compared to the existing vacuum boosters, the performance advantages of IEB are 1) robustness against environmental changes, 2) rapid hydraulic reactivity, etc., and the advantages of cost / university are 1) flexibility for powertrain changes 2) weight saving 3) package simplification. Although IEB has a great advantage in performance and cost, it still needs a lot of research in various fields to realize the braking feeling, which is the performance of the emotional aspect, similar to the existing system. [3, 4]
Park, Junho
Cellulose-Based Sensor Simultaneously Measures Pressure, Temperature, and HumidityTBMG-374818/1/2020
Researchers have developed a single sensor that combines the ability to measure pressure, temperature, and humidity simultaneously. The sensor has applications such as monitoring patients at home, robotics, electronic skin, functional textiles, surveillance, and security.
Graphene Lid Extends Photoemission Electron Microscopy to LiquidsTBMG-347537/1/2019
By capping liquids with graphene (an ultrathin sheet of pure carbon), researchers can easily image and analyze liquid interfaces and the surface of nanometer-scale objects immersed in liquids. In the imaging technique known as photoemission electron microscopy (PEEM), ultraviolet light or X-rays bombard a sample, stimulating the material to release electrons from a region at or just beneath its surface. Electric fields act as lenses, focusing the emitted electrons to create an image.
Mitigation of Community Noise from a Vacuum Excavator Using Simulations2019-01-14806/5/2019
Off-highway equipment operates in residential communities and must meet their radiated noise targets to be compliant with noise regulations and to be competitive in the marketplace. Traditional find and fix noise testing of late-stage prototype designs may cause launch delays, with intense time pressures that often result in missed opportunities to create excellent products with good value. Accurate simulation of noise from these machines allows noise targets to be assessed at each stage of product development, giving engineers time to develop low noise products without adding excessive manufacturing cost. Simulation of an early prototype of a new vacuum excavator showed excessive levels of radiated noise in two different frequency ranges. Further investigation of the simulation results of these two spectrum ranges indicated different noise mechanisms producing the excessive noise levels. An acoustic resonance was excited in the exhaust flow downstream of a silencer by highly vortical
Sanal, Rahul, Muthuraman, Karthik Mahadevan, Powell, Robert, Stellman, Vernon, Clevenger, Craig, Smith, Jeff
Experimental Strain Measurements of Highly-Curved BladesF-0075-2019-145765/13/2019
This paper presents an experimental-numerical investigation on the axial strain of highly-curved blades. Models of the blades were analyzed using a 2-D finite element code, SectionBuilder, coupled with a comprehensive analysis code, Dymore, and first validated using strain measurements under a static tip load. Frequency responses were obtained under an impulsive load for each of the blades with multiple boundary conditions and compared with the numerical models. Experimental measurements under centrifugal loading from 0 up to 3300 RPM in a vacuum showed the effect of curvature on the axial strain, with significant bending strains observed in the responses for the curved blades that were also well captured by the numerical analysis. The present analysis shows that even moderate levels of out-of-plane curvature significantly increases the strain magnitudes, while higher levels of in-plane curvature have a much smaller impact.
Sinotte, Tyler, Bauchau, Olivier
Brake Vacuum Booster Characterization2019-01-04124/2/2019
Brake vacuum booster characteristics are of great importance to understanding overall brake system operation in light vehicles so equipped. In recent years, engineering reports relevant to traffic crash reconstruction have discussed, among related areas, the operation of brake booster systems at high applied brake pedal force levels and with various levels of vacuum available within the booster. A vehicle-testing framework is presented for characterizing and understanding the operation of a vacuum booster with pedal force ranging above the vacuum runout point, as well as booster operation relative to varying levels of available vacuum and patterns of depletion of stored vacuum. Concepts are illustrated with measurements of exemplar vehicles. The objective of this paper is to promote improved understanding of brake booster operation and to advance more precise articulation of related concepts within the crash reconstruction community.
Walker, James, Rucoba, Robert, Barnes, Dan, Kent, Steven
Vacuum Gauge CalibrationARP7446 (Current)3/6/2019
This SAE Aerospace Recommended Practice (ARP) addresses the general procedure for the best practices for minimizing uncertainty when calibrating thermal conductivity and cold cathode vacuum gauges, which includes the vacuum sensor(s) and accompanying electronics necessary for a pressure measurement to be made. It also includes the best practices for an in-process verification where limitations make it impossible to follow the best practices for minimizing uncertainty. Verifying the accuracy and operation of vacuum gauges is critical to ensure the maintenance of processes while under vacuum.
AMS B Finishes Processes and Fluids Committee
Vacuum System Powers Modular Soft RobotTBMG-2794012/1/2017
Researchers at the Ecole Polytechnique Federale de Lausanne (EPFL) have created the first functional robot powered entirely by vacuum. It is made of soft building blocks that move by having air sucked out of them. The robot can be reconfigured to perform different tasks, like climbing vertical walls and grabbing objects.
Portable Bonding SystemF-0073-2017-120965/9/2017
ABSTRACT The current method used for bonding liners onto dynamic components requires the use of spring-loaded clamps, vacuum bags, and ovens. This process works well for our smaller articles although has posed problems for our larger bonding requirements. The primary problem for our large bonded components is our ovens would take up to 3.5 hrs. to heat the thickest areas up to bonding temperature. For the adhesives that we use the recommended temperature ramp-up time is 20-60 minutes. In addition, the thinner areas reach temperature sooner and would exceed the recommended maximum curing time of 60 min. A minimum of 25 pounds per square inch (PSI) is required to achieve a sound bondline. The clamps used during cure cycles rely on springs to apply pressure to the liner being bonded. The pressure they exert is not exact, and tends to vary. A vacuum bag can only apply the pressure that is supplied by shop air, 14.7 psi. The solution to achieving uniform and accurate pressure during bonding
Tuscano, Mark
Investigation of Performance Differences and Control Synthesis for Servo-Controlled and Vacuum-Actuated Wastegates2017-01-05923/28/2017
1 Turbocharging plays an important role in the downsizing of engines. Model-based approaches for boost control are going to increasing the necessity for controlling the wastegate flow more accurately. In today’s cars, the wastegate is usually only controlled with a duty cycle and without position feedback. Due to nonlinearities and varying disturbances a duty cycle does not correspond to a certain position. Currently the most frequently used feedback controller strategy is to use the boost pressure as the controller reference. This means that there is a large time constant from actuation command to effect in boost pressure, which can impair dynamic performance. In this paper, the performance of an electrically controlled vacuum-actuated waste-gate, subsequently referred to as vacuum wastegate, is compared to an electrical servo-controlled wastegate, also referred to as electric wastegate. Their performance is investigated with the two actuators installed on a turbocharged inline four
Holmbom, Robin, Liang, Bohan, Eriksson, Lars
Concept for Improving Cost Effectiveness of Thermoelectric Heat Recovery Systems2016-01-02334/5/2016
The practical application of heat recovery using thermoelectrics requires the realization of reasonable cost effectiveness. Therefore, a thermoelectric generator (TEG) structure that can compatibly increase efficiency and reduce cost was investigated with the aim of enhancing cost effectiveness. To increase efficiency, a method of using a vacuum space structure to reduce the TEG size was investigated to enable installation just after the close-coupled catalyzer, which is subject to many space restrictions. It was found that by making it possible to use high temperature exhaust heat, power generation efficiency can be increased to approximately twice that of the typical under floor installation. In addition, coupled simulation of heat transfer and power generation using FEM, 1D cost effectiveness simulations, and bench tests were performed with the aim of reducing cost. These results clarified that use of a TEG with a heat concentration structure enabled to reduce the number of elements
Mori, Masayoshi, Matsumoto, Manabu, Ohtani, Makoto
Innovative Approach to Circumferential Splicing for Large Aircraft Assembly2015-01-25049/15/2015
The joining and assembly of barrel sections of large aircraft is always cumbersome. Any means to ease this task are welcome. In recent years The Boeing Co. has invented and licensed their “Flex-Track” system. But however flexible this approach may be, double curved surfaces, large variations of cross-section radius and issues with vacuum cup fixture are problems to be dealt with. Zhejiang University in Hangzhou, China has developed a new, innovative circumferential splicing system in cooperation with Broetje-Automation, Germany. There is a unique, time-saving setup technology and self-stepping actuation for a one up 360° splicing operation. The process endeffector is based on standard, state of the art components in use for large fastening systems. Features are high speed servo drilling spindle with HSK 32 drill chuck holder, tool changer, vacuum chip removal, reference hole detection and correction, surface normality alignment, pressure foot clamp-up, countersink control. An area of
Meiners, Christian, Zhu, Weidong, Ke, Yinglin
Development of Free Molecule Flow Equations from a Transient, Asymmetric SourceTBMG-228829/1/2015
The analysis and simulation of gases expanding from sources such as rocket nozzles into vacuum, or the effects plumes from these sources create when they interact with solid surfaces, present a considerable challenge to the scientific and engineering communities. As a plume expands into vacuum, density levels, and hence collision rates, decrease rapidly by many orders of magnitude. The main difficulty lies in accurately describing a flow field extending from continuum flow at the nozzle exit, through the transition regime, and reaching free molecule behavior within a relatively short distance downstream. For thrusters, flow at the nozzle exit is usually characterized by high exit velocities and relatively high Mach numbers. Even in regions where significant intermolecular collision rates occur, relative velocity levels are low, and little thermal scattering occurs normal to the mainly radial streamlines. Such observations lead one to consider describing the expansion under certain
Advanced-Capabilities Medical Suction DeviceTBMG-224307/1/2015
NASA has long recognized the difficulty in providing emergency medical care to astronauts in space. Many aspects of space travel make medical care inherently difficult, and sufficient storage space for medical equipment severely limits the ability to carry a full complement of diagnostic and therapeutic equipment onboard. The Microgravity Compatible Medical Suction Device (MCMSD) enables aspiration and containment of bodily fluids and vomitus, while preventing the transmission of infectious agents.
Investigation on Torque Jump Up and Vibration at High Rotation Speed of a Wet Clutch2015-01-21846/15/2015
Reduction of the drag torque and longevity of the clutch assembly are the most important factors for vehicle transmission improvement. The decreasing trend of the drag torque with speed after its peak is a common characteristic of the clutch assembly. Several theoretical models have been presented by the researchers describing the drag torque characteristics at lower clutch speed. However, very little study has been made on the drag torque behavior at very high clutch speed (6000∼10000+ rpm). The alarming jump of the drag torque at high speed operating condition remains unexplained till date. In this paper, we investigated the possible reasons of torque jump up at high rotation speed and solution to overcome this problem. We presented an analytical correlation of torque jump up with the excessive decrease of local static pressure and assumed that vacuum formation is the possible reason of high speed torque rising and associated vibration. Result shows that when the separator plates are
Mahmud, Syeda, Pahlovy, Shahjada
Sweeping Vehicle Vacuum Dust Control System Research2015-01-05034/14/2015
Plenty of dust particles which are generated when a sweeping vehicle is dumping harm to workers' health. In the study, the designed vacuum dust control system could effectively capture easily raised dust particles in the air in the premise of not impacting the dumping process so as to improve the unloading work environment. Firstly, longitudinal motion trajectory model of dust particles in the dumping process is established. Based on the side collision probability model of dust particles, lateral velocity distribution of dust particles is obtained. What's more, the scope of lateral dust particles is determined. Taking into account coupling of the dust control system and the working state of the vehicle, the suction mouth is arranged at the edge on the outside of hatch cover. Centrifugal horizontal dust removal system designed in the research is fixed in the middle of the filter cover part and discharging hatch cover area. The original vehicle hydraulic system is utilized to provide the
Zhan, Hefeng, Tan, Gangfeng, Xu, Haobo, Li, Xin, Wang, Zhaohua, Wang, Can
The Comparative Study of Gasoline and n-butanol on Spray Characteristics2014-01-275410/13/2014
n-butanol has been recognized as a promising alternative fuel for gasoline and may potentially overcome the drawbacks of methanol and ethanol, e.g. higher energy density. In this paper, the spray characteristics of gasoline and n-butanol have been investigated using a high pressure direct injection injector. High speed imaging and Phase Doppler Particle Analyzer (PDPA) techniques were used to study the spray penetration and the droplet atomization process. The tests were carried out in a high pressure constant volume vessel over a range of injection pressure from 60 to 150 bar and ambient pressure from 1 to 5 bar. The results show that gasoline has a longer penetration length than that of n-butanol in most test conditions due to the relatively small density and viscosity of gasoline; n-butanol has larger SMD due to its higher viscosity. The increase in ambient pressure leads to the reduction in SMD by 42% for gasoline and by 37% for n-butanol. Based on the development of droplet
Li, Yanfei, Guo, Hengjie, Wang, Jian-Xin, Xu, Hongming
Description and Performance Analysis of a Flow Test Rig to Simulate Altitude Pressure Variation for Internal Combustion Engines Testing2014-01-258210/13/2014
Calibration of internal combustion engines at different altitudes, above or below sea level, is important to improve engine performance and to reduce fuel consumption and emissions in these conditions. In this work, a flow test rig that reproduces altitude pressure variation is presented. The system stands out by its altitude range, compactness, portability and easy control. It is based on the use of turbomachinery to provide the target pressure to the engine intake and exhaust lines. The core of the system is composed of a variable geometry turbine (VGT) with a waste-gate (WG) and a mechanical compressor. Given a set of turbomachinery systems, the operation pressure and the air mass flow are controlled by the speed of the mechanical compressor and the VGT and WG position. A simple modification in the installation setup makes possible to change the operating mode from vacuum to overpressure. So that simulating altitude increase or decrease with the same flow test rig components. The
Galindo, José, Serrano, José Ramón, Piqueras, Pedro, Gómez, Javier
Effects of Supplemental Vacuum Production to Support Braking2014-01-25289/28/2014
This paper will discuss how different forms of producing supplemental vacuum have varying effects on overall vehicle efficiency. The once reliable source of vacuum from the engine is becoming increasingly scarce due to higher efficiencies from modern IC engines and the growing use of turbochargers. This need for supplemental vacuum has led to several solutions to support vacuum needs, particularly for supplying the booster for brake assist. Using simulated vehicle environments for the various forms of supplemental vacuum the behavior of each can be better understood. Using this simulated environment the actual power consumed by each method of supplemental vacuum production can be accurately measured over various drive cycles and conditions including engine speed and brake applications. Depending on the means of supplemental vacuum the respective energy consumption can be applied to a vehicle model to show the end effects of each solution on a number of levels.
Scopacasa, Dominic D.
Analysis of Hydraulic Retarder Air-Friction Characteristics2014-01-25049/28/2014
The retarder is an important auxiliary braking device of heavy vehicles. However, the stirring air in the working wheels of the idle retarder would cause the transmission loss when the vehicle is traveling in non-braking state [1]. For certain driving conditions, the air-friction characteristics in the working wheels of the idle retarder are analyzed first. Then the relationship between the air density and the torque produced by stirring air is studied. The thermal characteristics of the retarder in the idle condition are also concerned according to the energy flow and heat transfer. Meanwhile, the increased transmission loss caused by the rising temperature of the stirring air and its inference on the transmission stability are also studied. Finally, the optimal range of air vacuum degrees in the working wheel of the idle retarder is determined and the evaluations for the air-friction and the heat transfer characteristics are given for the vacuum degrees. The result shows that, the
Wang, Can, Tan, Gangfeng, Guo, Xuexun, Chen, Ming, Huang, Chuizong, Liu, Wei
The Influence of Vacuum Booster Design Parameters on Brake Pedal Feel2014-01-24999/28/2014
Brake pedal feel characteristic is determined by the structural and kinetic parameters of the components of the brake system. As the servo power component of the brake system, vacuum booster has a significant influence on the brake pedal feel. In this paper, a brake system model for brake pedal feel which has a detail vacuum booster mathematical description is established in the software MATLAB/Simulink. The structure gaps, spring preload, friction force and reaction disc characteristics of vacuum booster are considered in this model. A brake pedal feel bench test under different input velocity and vacuum pressure is completed in order to validate the prediction of the model. Finally, based on the assessment index in pedal travel, pedal force and master cylinder pressure three-quadrant diagram, the influence of vacuum booster design parameters such as structure gaps, spring preloads, press plate and press ring areas, diaphragm effective area and reaction disc stiffness on the brake
Zhang, Lijun, Ruan, Cheng, Meng, Dejian
Cumulative Damage Analysis for Hydraulic Hose AssembliesJ1927_201406 (Current)6/4/2014
This SAE Information Report is intended to provide the hydraulic system analyst with a procedure which will assist in the selection and use of high-pressure wire reinforced hydraulic hose assemblies. Many construction, agricultural, industrial, or commercial equipment systems utilize hydraulic hose assemblies that are subjected to irregular cyclic pressure variations (cannot be approximated by a constant amplitude pressure cycle). This document relates damage done by pressure cycles with the pressure-life performance curve for the hose assembly being evaluated, using a linear damage rule to predict fatigue life similar to that used for predicting metal fatigue life. More detailed information on the subject may be found in SAE Paper No. 880713. The accuracy of cumulative damage calculations is directly related to proper measurement of the service pressure history and pressure-life performance for the hose assembly being evaluated. Final selection of a hose assembly must also consider
Vacuum Cleaning Vehicle Dust Subsidence System Design2014-01-07504/1/2014
Vacuum cleaning vehicle is the necessary equipment for the Municipal Sanitation Department to keep the road surface clean and the dust subsidence system is the heart unit for the proper function of the cleaning vehicle. The reasonable design of this system could increase the load capacity of the vehicle and be convenient for the garbage collecting and dumping. Meanwhile, the engine power could be relatively reduced and the influence on the environment duo to the dusty air in the outlet could be also effectively improved. In the study, the gravity dedusting principle is used firstly for structure design to reduce the flow rate of dust particles inside the lower part of the dust subsidence system. The ruleless collision loss among dust particles is reduced and thereby the fan power is saved. By means of a reasonable separated chamber design and the use of inertia baffle, the sort management for dust particles is developed and the work stress of the export filter is released observably
Tan, Gangfeng, Chen, Ming, Xu, Haobo, Luo, Bing, Wang, Jiameng
Comparison of Tribological Performance of WS 2 Nanoparticles, Microparticles and Mixtures Thereof2014-01-09494/1/2014
Tribological performance of tungsten sulfide (WS2) nanoparticles, microparticles and mixtures of the two were investigated. Previous research showed that friction and wear reduction can be achieved with nanoparticles. Often these improvements were mutually exclusive, or achieved under special conditions (high temperature, high vacuum) or with hard-to-synthesize inorganic-fullerene WS2 nanoparticles. This study aimed at investigating the friction and wear reduction of WS2 of nanoparticles and microparticles that can be synthesized in bulk and/or purchased off the shelf. Mixtures of WS2 nanoparticles and microparticles were also tested to see if a combination of reduced friction and wear would be achieved. The effect of the mixing process on the morphology of the particles was also reported. The microparticles showed the largest reduction in coefficient of friction while the nanoparticles showed the largest wear scar area reduction. Mixtures of nanoparticles and microparticles did not
Daly Flynn, Kelly, Harta, Ionut C., Schall, J. David
Researchers Build A Better Device to Detect Ultraviolet LightTBMG-1869911/1/2013
Researchers in Japan have developed a new type of photodiode that can detect in just milliseconds a certain type of high-energy ultraviolet light, called UVC, which is powerful enough to break the bonds of DNA and harm living creatures. Although this radiation doesn't normally reach the Earth's surface, it can leak through to just below the hole in the ozone layer. Monitoring this radiation is a way of tracking the hole in the ozone layer, and photodiodes that measure UVC are also used as flame sensors and for communication in space.
JWST Integrated Science Instrument Module Alignment Optimization ToolTBMG-1745810/1/2013
During cryogenic vacuum testing of the James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM), the global alignment of the ISIM with respect to the designed interface of the JWST optical telescope element (OTE) will be measured through a series of optical characterization tests. These tests will determine the locations and orientations of the JWST science instrument projected focal surfaces and entrance pupils with respect to their corresponding OTE optical interfaces. If any optical performance non-compliances are identified, the ISIM will be adjusted to improve its performance. In order to understand how to manipulate the ISIM’s degrees of freedom properly and to prepare for the ISIM flight model testing, a series of opticalmechanical analyses have been completed to develop and identify the best approaches for bringing a non-compliant ISIM element into compliance.
Microgravity Storage Vessels and Conveying- Line Feeders for Cohesive RegolithTBMG-169648/1/2013
Under microgravity, the usual methods of placing granular solids into, or extracting them from, containers or storage vessels will not function. Alternative methods are required to provide a motive force to move the material. New configurations for microgravity regolith storage vessels that do not resemble terrestrial silos, hoppers, or tanks are proposed. The microgravity-compatible bulk-material storage vessels and exitfeed configurations are designed to reliably empty and feed cohesive material to transfer vessels or conveying ducts or lines without gravity. A controllable motive force drives the cohesive material to the exit opening(s), and provides a reliable means to empty storage vessels and/or to feed microgravity conveying lines. The proposed designs will function equally well in vacuum, or inside of pressurized enclosures.
Determining Temperature Differential to Prevent Hardware Cross- Contamination in a Vacuum ChamberTBMG-159193/1/2013
When contamination-sensitive hardware must be tested in a thermal vacuum chamber, cross-contamination from other hardware present in the chamber, or residue from previous tests, becomes a concern. Typical mitigation strategies involve maintaining the temperature of the critical item above that of other hardware elements at the end of the test.
Validation of Proposed Metrics for Two-Body Abrasion Scratch Test Analysis StandardsTBMG-156542/1/2013
Abrasion of mechanical components and fabrics by soil on Earth is typically minimized by the effects of atmosphere and water. Potentially abrasive particles lose sharp and pointed geometrical features through erosion. In environments where such erosion does not exist, such as the vacuum of the Moon, particles retain sharp geometries associated with fracturing of their parent particles by micrometeorite impacts. The relationship between hardness of the abrasive and that of the material being abraded is well understood, such that the abrasive ability of a material can be estimated as a function of the ratio of the hardness of the two interacting materials. Knowing the abrasive nature of an environment (abrasive)/construction material is crucial to designing durable equipment for use in such surroundings.
Using Combustion Synthesis to Reinforce Berms and Other Regolith StructuresTBMG-156702/1/2013
The Moonraker Excavator and other tools under development for use on the Moon, Mars, and asteroids will be employed to construct a number of civil engineering projects and to mine the soil. Mounds of loose soil will be subject to the local transport mechanisms plus artificial mechanisms such as blast effects from landers and erosion from surface vehicles. Some of these structures will require some permanence, with a minimum of maintenance and upkeep.
Numerical Simulation of Rocket Exhaust Interaction With Lunar SoilTBMG-1527112/1/2012
This technology development originated from the need to assess the debris threat resulting from soil material erosion induced by landing spacecraft rocket plume impingement on extraterrestrial planetary surfaces. The impact of soil debris was observed to be highly detrimental during NASA’s Apollo lunar missions and will pose a threat for any future landings on the Moon, Mars, and other exploration targets.
Sustainable Technologies Category Winner (Winner of an HP Workstation)TBMG-1516111/1/2012
Bill Zebuhr, Scott Newquist, David Dussault, E. Andrew Condon, Steven Sahagian, Nicholas Wong, Michael Easton, William Burie, Charles Blanchard, and Nicole Sandoval, Aquaback Technologies, Tewksbury, MA
Adjusting Permittivity by Blending Varying Ratios of SWNTsTBMG-1508511/1/2012
A new composite material of singlewalled carbon nanotubes (SWNTs) displays radio frequency (0 to 1 GHz) permittivity properties that can be adjusted based upon the nanotube composition. When varying ratios of raw to functionalized SWNTs are blended into the silicone elastomer matrix at a total loading of 0.5 percent by weight, a target real permittivity value can be obtained between 70 and 3. This has particular use for designing materials for microwave lenses, microstrips, filters, resonators, high-strength/low-weight electromagnetic interference (EMI) shielding, antennas, waveguides, and low-loss magneto-dielectric products for applications like radome construction.
The Mobile ChamberTBMG-1487210/1/2012
A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base.
Polyurea-Based Aerogel Monoliths and CompositesTBMG-146129/1/2012
A flexible, organic polyurea-based aerogel insulation material was developed that will provide superior thermal insulation and inherent radiation protection for government and commercial applications. The rubbery polyurea-based aerogel exhibits little dustiness, good flexibility and toughness, and durability typical of the parent polyurea polymer, yet with the low density and superior insulation properties associated with aerogels. The thermal conductivity values of polyurea-based aerogels at lower temperature under vacuum pressures are very low and better than that of silica aerogels.
Experimental Modeling of Sterilization Effects for Atmospheric Entry Heating on MicroorganismsTBMG-142368/1/2012
The objective of this research was to design, build, and test an experimental apparatus for studying the parameters of atmospheric entry heating, and the inactivation of temperature-resistant bacterial spores. The apparatus is capable of controlled, rapid heating of sample coupons to temperatures of 200 to 350 ºC and above. The vacuum chamber permits operation under vacuum or special atmospheric gas mixtures.
Method to Remove Particulate Matter From Dusty Gases at Low PressuresTBMG-140757/1/2012
Future human exploration of Mars will rely on local Martian resources to reduce the mass, cost, and risk of space exploration launched from Earth. NASA’s In Situ Resource Utilization (ISRU) Project seeks to produce mission consumables from local Martian resources, such as atmospheric gas. The Martian atmosphere, however, contains dust particles in the 2-to-10 -micrometer range. These dust particles must be removed before the Martian atmospheric gas can be processed. The low pressure of the Martian atmosphere, at 5 to 10 mbars, prevents the development of large voltages required for a standard electrostatic precipitator. If the voltage is increased too much, the corona transitions into a glow/streamer discharge unsuitable for the operation of a precipitator. If the voltage is not large enough, the dust particles are not sufficiently charged and the field is not strong enough to drive the particles to the collector.
Versatile Controller for Infrared Lamp and Heater ArraysTBMG-140537/1/2012
A paper describes a modular design for new controllers for infrared heating during cruise stage solar thermal vacuum test of the Mars Science Laboratory. The controllers had to be easy to use and maintain, used with a wide variety of different control schemes, and made using commercial off-the-shelf (COTS) components wherever possible.
Direct-Write Polymer Nanolithography in Ultra-High VacuumTBMG-139156/1/2012
The deposition of materials in vacuum is the foundational technology for creating modern electronic circuits; a vacuum being essential both to preserve the cleanliness of the substrate and the deposited materials, and to minimize the creation of defects. Consequently, most deposition techniques, from thermal evaporation to atomic layer deposition, require a high level of vacuum, preferably ultra-high vacuum (UHV), to be used effectively.
Development of Advanced Oil Separator to Give Uniform Oil Separation Efficiency across Engine Speed and Load Conditions2012-01-01794/16/2012
Common rail direct injection technologies have enabled the development of very high power and torque for a given capacity of the engine. These high performance engines have very high brake mean effective pressures and peak firing pressures. These high pressures increase the blow-by gas flow in cylinder crankcase. Vehicle brake assist systems as well as some actuators on engine need the vacuum. The vacuum is generated by the vacuum pump driven by the engine cam shaft or separately as accessory drive. The air pulled for creating the vacuum gets mixed with the lubricating oil. This air mixture with the lubrication oil gets circulated in the blow by circuit. Collectively, blow-by gases and the vacuum pump oil with air carry substantial engine oil particles. These oil particles need to be separated before connecting to the air intake circuit to reduce oil consumption and to reduce exhaust emissions. Generally cyclone type oil mist separation systems are used on the automobile engines. The
Kolhe, Vivek, Sharma, Manu, Veeramani, K, kulkarni, Makarand, Ravva, Ravindra
Low-Cost, Rugged High-Vacuum SystemTBMG-132684/1/2012
A need exists for miniaturized, rugged, low-cost high-vacuum systems. Recent advances in sensor technology have led to the development of very small mass spectrometer detectors as well as other analytical instruments such as scanning electron microscopes. However, the vacuum systems to support these sensors remain large, heavy, and power-hungry. To meet this need, a miniaturized vacuum system was developed based on a very small, rugged, and inexpensive-to-manufacture molecular drag pump (MDP). The MDP is enabled by a miniature, very-high-speed (200,000 rpm), rugged, low-power, brushless DC motor optimized for wide temperature operation and long life.
Sealing Materials for Use in Vacuum at High TemperaturesTBMG-130443/1/2012
Sealing materials that can be applied and left in place in vacuum over a wide range of temperatures (especially temperatures of a few thousand degrees Celsius) have been conceived and investigated for potential utility in repairing thermal-protection tiles on the space shuttles in orbit before returning to Earth. These materials are also adaptable to numerous terrestrial applications that involve vacuum processing and/or repair of structures that must withstand high temperatures. These materials can be formulated to have mechanical handling characteristics ranging from almost freely flowing liquid- like consistency through paste-like consistency to stiff putty-like consistency, and to retain these characteristics in vacuum until heated to high curing temperatures.
Large-Area Vacuum Ultraviolet SensorsTBMG-126151/1/2012
Pt/(n-doped GaN) Schottky-barrier diodes having active areas as large as 1 cm square have been designed and fabricated as prototypes of photodetectors for the vacuum ultraviolet portion (wavelengths ≈200 nm) of the solar spectrum. In addition to having adequate sensitivity to photons in this wavelength range, these photodetectors are required to be insensitive to visible and infrared components of sunlight and to have relatively low levels of dark current.
Thermionic Power Cell To Harness Heat Energies for Geothermal ApplicationsTBMG-1223912/1/2011
A unit thermionic power cell (TPC) concept has been developed that converts natural heat found in high-temperature environments (460 to 700 ºC) into electrical power for in situ instruments and electronics. Thermionic emission of electrons occurs when an emitter filament is heated to “white hot” temperatures (>1,000 ºC) allowing electrons to overcome the potential barrier and emit into the vacuum. These electrons are then collected by an anode, and transported to the external circuit for energy storage.
Development of Smart Booster Brake Systems for Regenerative Brake Cooperative Control2011-01-23569/18/2011
In regenerative braking, the kinetic energy of the vehicle is stored in a battery as the electric energy that is otherwise being dissipated as heat by friction, so that the stored energy is recuperated to drive the vehicle. In general, another independent braking mechanism, such as hydraulic brakes, needs to be used in cooperation with regenerative braking in order to meet the total braking force demand. The smart booster system, which uses a permanent magnet synchronous motor to replace the conventional vacuum booster, is proposed in this paper as an active braking system which is well suited for such regenerative cooperative braking applications in environment friendly vehicles. A pressure feedback control is used with a nested current control loop using pressure and current sensors, respectively. Two types of smart booster systems are investigated for different applications, and the samples of both types of smart booster systems are built to check the feasibility of the proposed
Yeo, Hoon, Koo, Changhoe, Jung, Wankyo, Kim, Dokun, Cheon, Jae Seung
Piezoelectrically Enhanced PhotocathodesTBMG-108529/1/2011
Doping of photocathodes with materials that have large piezoelectric coefficients has been proposed as an alternative means of increasing the desired photoemission of electrons. Treating cathode materials to increase emission of electrons is called “activation” in the art. It has been common practice to activate photocathodes by depositing thin layers of suitable metals (usually, cesium). Because cesium is unstable in air, fabrication of cesiated photocathodes and devices that contain them must be performed in sealed tubes under vacuum. It is difficult and costly to perform fabrication processes in enclosed, evacuated spaces. The proposed piezoelectrically enhanced photocathodes would have electron-emission properties similar to those of cesiated photocathodes but would be stable in air, and therefore could be fabricated more easily and at lower cost.
Polymerization Initiated at the Sidewalls of Carbon NanotubesTBMG-108509/1/2011
A process has been developed for growing polymer chains via anionic, cationic, or radical polymerization from the side walls of functionalized carbon nanotubes, which will facilitate greater dispersion in polymer matrices, and will greatly enhance reinforcement ability in polymeric material.
Steel, Welding Wire, 1.05Cr - 0.55Ni - 1.0Mo - 0.08V (0.26 - 0.32C), Vacuum Melted, Environment-Controlled PackagingAMS5027C (Historical)8/10/2011
This specification covers a low-alloy steel in the form of welding wire.
AMS E Carbon and Low Alloy Steels Committee
Vacuum Camera CoolerTBMG-107528/1/2011
Acquiring cheap, moving video was impossible in a vacuum environment, due to camera overheating. This overheating is brought on by the lack of cooling media in vacuum. A water-jacketed camera cooler enclosure machined and assembled from copper plate and tube has been developed.
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