Performance of a prototype surface collector for juvenile salmonids at Bonneville dam's first powerhouse on the Columbia River, Oregon

USGS Publications Warehouse

Evans, S.D.; Adams, N.S.; Rondorf, D.W.; Plumb, J.M.; Ebberts, B.D.

2008-01-01

During April-July 2000, we radio-tagged and released juvenile Chinook salmon (Oncorhynchus tshawytscha) and steelhead (Oncorhynchus mykiss) to evaluate a prototype surface flow bypass at Bonneville Dam on the Columbia River. The mock bypass, called a prototype surface collector (PSC), had six vertical slot entrances that were each 6 m wide and 12 m deep. The PSC was retrofitted to the upstream face of Bonneville Dam's First Powerhouse. Our objectives were to: (1) assess species-specific differences in movement patterns and behaviour of fish within 6 m of the face of the PSC, (2) estimate the efficiency and effectiveness of the PSC and (3) evaluate factors affecting the performance of the PSC. We found that 60-72% of the fish, depending on species, detected within 6 m of the PSC entered it. Of the fish that passed the First Powerhouse at turbines 1-6, 79-83% entered the PSC. Diel period was a significant contributor to PSC performance for all species, and day of year was a significant contributor to PSC performance for subyearling Chinook salmon. The PSC was twice as effective (%fish/%flow) as the spillway, passing 2.5:1 steelhead and subyearling Chinook salmon and 2.4:1 yearling Chinook salmon per unit of water. If fully implemented, the PSC would increase the percentage of fish that pass the First Powerhouse through non-turbine routes from 65-77% (without the PSC) to 76-85% (with the PSC), depending on species. Published in 2008 by John Wiley & Sons, Ltd.

The endo-rectal probe prototype for the TOPEM project

NASA Astrophysics Data System (ADS)

Musico, Paolo; TOPEM Collaboration

2016-07-01

The TOPEM project was funded by INFN with the aim of studying the design of a TOF-PET system dedicated to prostate imaging. During last year a big effort was put into building the prototype of the endo-rectal probe from all point of view: mechanical, thermal, electrical. A dedicated integrated circuit was adopted to have the minimum dimensions: the TOFPET ASIC. The system is composed by a LYSO pixellated crystal which is seen by a 128 SiPM matrix on both surfaces: this permits Depth Of Interaction (DOI) measurement. The 4 needed ASICs are handled by a FPGA board which transmits the acquired data over an UDP connection. The external container was made using 3-D printing technology: internal channels on the external surface permit the flowing of controlled temperature (≈35 °C) water. Electronic components power is dissipated using an internal air flow kept at lower temperature (≈20 °C). The probe is MR compatible: a dedicated small antenna can be accommodated in the container. This will permit simultaneous imaging in MRI and PET systems.

Reconstructing 3-D skin surface motion for the DIET breast cancer screening system.

PubMed

Botterill, Tom; Lotz, Thomas; Kashif, Amer; Chase, J Geoffrey

2014-05-01

Digital image-based elasto-tomography (DIET) is a prototype system for breast cancer screening. A breast is imaged while being vibrated, and the observed surface motion is used to infer the internal stiffness of the breast, hence identifying tumors. This paper describes a computer vision system for accurately measuring 3-D surface motion. A model-based segmentation is used to identify the profile of the breast in each image, and the 3-D surface is reconstructed by fitting a model to the profiles. The surface motion is measured using a modern optical flow implementation customized to the application, then trajectories of points on the 3-D surface are given by fusing the optical flow with the reconstructed surfaces. On data from human trials, the system is shown to exceed the performance of an earlier marker-based system at tracking skin surface motion. We demonstrate that the system can detect a 10 mm tumor in a silicone phantom breast.

Science Operations for the 2008 NASA Lunar Analog Field Test at Black Point Lava Flow, Arizona

NASA Technical Reports Server (NTRS)

Garry W. D.; Horz, F.; Lofgren, G. E.; Kring, D. A.; Chapman, M. G.; Eppler, D. B.; Rice, J. W., Jr.; Nelson, J.; Gernhardt, M. L.; Walheim, R. J.

2009-01-01

Surface science operations on the Moon will require merging lessons from Apollo with new operation concepts that exploit the Constellation Lunar Architecture. Prototypes of lunar vehicles and robots are already under development and will change the way we conduct science operations compared to Apollo. To prepare for future surface operations on the Moon, NASA, along with several supporting agencies and institutions, conducted a high-fidelity lunar mission simulation with prototypes of the small pressurized rover (SPR) and unpressurized rover (UPR) (Fig. 1) at Black Point lava flow (Fig. 2), 40 km north of Flagstaff, Arizona from Oct. 19-31, 2008. This field test was primarily intended to evaluate and compare the surface mobility afforded by unpressurized and pressurized rovers, the latter critically depending on the innovative suit-port concept for efficient egress and ingress. The UPR vehicle transports two astronauts who remain in their EVA suits at all times, whereas the SPR concept enables astronauts to remain in a pressurized shirt-sleeve environment during long translations and while making contextual observations and enables rapid (less than or equal to 10 minutes) transfer to and from the surface via suit-ports. A team of field geologists provided realistic science scenarios for the simulations and served as crew members, field observers, and operators of a science backroom. Here, we present a description of the science team s operations and lessons learned.

Advanced evacuated tube collectors

NASA Astrophysics Data System (ADS)

Schertz, W. W.; Hull, J. R.; Winston, R.; Ogallagher, J.

1985-04-01

The essence of the design concept for these new collectors is the integration of moderate levels of nonimaging concentration inside the evacuated tube itself. This permanently protects the reflection surfaces and allows the use of highly reflecting front surface mirrors with reflectances greater than 95%. Previous fabrication and long term testing of a proof-of-concept prototype has established the technical success of the concept. Present work is directed toward the development of a manufacturable unit that will be suitable for the widest possible range of applications. Design alternatives include scaling up the original prototype's tube diameter from 5 cm to 10 cm, using an internal shaped metal concentrating reflector, using a variety of profile shapes to minimize so-called gap losses and accommodate both single ended and double-ended flow geometries, and allowing the use of heat pipes for the absorber tube.

Technical report on prototype intelligent network flow optimization (INFLO) dynamic speed harmonization and queue warning.

DOT National Transportation Integrated Search

2015-06-01

This Technical Report on Prototype Intelligent Network Flow Optimization (INFLO) Dynamic Speed Harmonization and Queue Warning is the final report for the project. It describes the prototyping, acceptance testing and small-scale demonstration of the ...

Experimental investigation of active rib stitch knitted architecture for flow control applications

NASA Astrophysics Data System (ADS)

Abel, Julianna M.; Mane, Poorna; Pascoe, Benjamin; Luntz, Jonathan; Brei, Diann

2010-04-01

Actively manipulating flow characteristics around the wing can enhance the high-lift capability and reduce drag; thereby, increasing fuel economy, improving maneuverability and operation over diverse flight conditions which enables longer, more varied missions. Active knits, a novel class of cellular structural smart material actuator architectures created by continuous, interlocked loops of stranded active material, produce distributed actuation that can actively manipulate the local surface of the aircraft wing to improve flow characteristics. Rib stitch active knits actuate normal to the surface, producing span-wise discrete periodic arrays that can withstand aerodynamic forces while supplying the necessary displacement for flow control. This paper presents a preliminary experimental investigation of the pressuredisplacement actuation performance capabilities of a rib stitch active knit based upon shape memory alloy (SMA) wire. SMA rib stitch prototypes in both individual form and in stacked and nestled architectures were experimentally tested for their quasi-static load-displacement characteristics, verifying the parallel and series relationships of the architectural configurations. The various configurations tested demonstrated the potential of active knits to generate the required level of distributed surface displacements while under aerodynamic level loads for various forms of flow control.

Design and performance analysis of an aero-maneuvering orbital-transfer vehicle concept

NASA Technical Reports Server (NTRS)

Menees, G. P.

1985-01-01

Systems requirements for design-optimized, lateral-turn performance were determined for reusable, space-based applications and low-Earth orbits involving large multiple plane-inclination changes. The aerothermodynamic analysis is the most advanced available for rarefield-hypersonic flow over lifting surfaces at incidence. The effects of leading-edge bluntness, low-density viscous phenomena, and finite-rate flow-field chemistry and surface catalysis are accounted for. The predicted aerothermal heating characteristics are correlated with thermal-control and flight-performance capabilities. The mission payload capacity for delivery, retrieval, and combined operations was determined for round-trip sorties extending to polar orbits. Recommendations are given for future design refinements. The results help to identify technology issues required to develop prototype operational vehicles.

Aerothermodynamic heating and performance analysis of a high-lift aeromaneuvering AOTV concept

NASA Technical Reports Server (NTRS)

Menees, G. P.; Brown, K. G.; Wilson, J. F.; Davies, C. B.

1985-01-01

The thermal-control requirements for design-optimized aeromaneuvering performance are determined for space-based applications and low-earth orbit sorties involving large, multiple plane-inclination changes. The leading-edge heating analysis is the most advanced developed for hypersonic-rarefied flow over lifting surfaces at incidence. The effects of leading-edge bluntness, low-density viscous phenomena, and finite-rate flow-field chemistry and surface catalysis are accounted for. The predicted aerothermodynamic heating characteristics are correlated with thermal-control and flight-performance capabilities. The mission payload capability for delivery, retrieval, and combined operations is determined for round-trip sorties extending to polar orbits. Recommendations are given for future design refinements. The results help to identify technology issues required to develop prototype operational systems.

A new model of centrifugal blood pump for cardiopulmonary bypass: design improvement, performance, and hemolysis tests.

PubMed

Leme, Juliana; Fonseca, Jeison; Bock, Eduardo; da Silva, Cibele; da Silva, Bruno Utiyama; Dos Santos, Alex Eugênio; Dinkhuysen, Jarbas; Andrade, Aron; Biscegli, José F

2011-05-01

A new model of blood pump for cardiopulmonary bypass (CPB) application has been developed and evaluated in our laboratories. Inside the pump housing is a spiral impeller that is conically shaped and has threads on its surface. Worm gears provide an axial motion of the blood column. Rotational motion of the conical shape generates a centrifugal pumping effect and improves pumping performance. One annular magnet with six poles is inside the impeller, providing magnetic coupling to a brushless direct current motor. In order to study the pumping performance, a mock loop system was assembled. Mock loop was composed of Tygon tubes (Saint-Gobain Corporation, Courbevoie, France), oxygenator, digital flowmeter, pressure monitor, electronic driver, and adjustable clamp for flow control. Experiments were performed on six prototypes with small differences in their design. Each prototype was tested and flow and pressure data were obtained for rotational speed of 1000, 1500, 2000, 2500, and 3000 rpm. Hemolysis was studied using pumps with different internal gap sizes (1.35, 1.45, 1.55, and 1.7 mm). Hemolysis tests simulated CPB application with flow rate of 5 L/min against total pressure head of 350 mm Hg. The results from six prototypes were satisfactory, compared to the results from the literature. However, prototype #6 showed the best results. Best hemolysis results were observed with a gap of 1.45 mm, and showed a normalized index of hemolysis of 0.013 g/100 L. When combined, axial and centrifugal pumping principles produce better hydrodynamic performance without increasing hemolysis. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Mixed-Dimensionality VLSI-Type Configurable Tools for Virtual Prototyping of Biomicrofluidic Devices and Integrated Systems

DTIC Science & Technology

2002-10-01

proximity to this aluminum bar, then the aluminum element would serve as a heat pipe to rapidly distribute heat to the center sensor and the floor...for a Bent Square Pipe ......................................................... 86 7.3 One-Cell Model for Free Surface Flows...90 7.4.2 Filament Application for Fluid Heating in Microreactor...................................... 91 7.4.3 Model

Biomedical device prototype based on small scale hydrodynamic cavitation

NASA Astrophysics Data System (ADS)

Ghorbani, Morteza; Sozer, Canberk; Alcan, Gokhan; Unel, Mustafa; Ekici, Sinan; Uvet, Huseyin; Koşar, Ali

2018-03-01

This study presents a biomedical device prototype based on small scale hydrodynamic cavitation. The application of small scale hydrodynamic cavitation and its integration to a biomedical device prototype is offered as an important alternative to other techniques, such as ultrasound therapy, and thus constitutes a local, cheap, and energy-efficient solution, for urinary stone therapy and abnormal tissue ablation (e.g., benign prostate hyperplasia (BPH)). The destructive nature of bubbly, cavitating, flows was exploited, and the potential of the prototype was assessed and characterized. Bubbles generated in a small flow restrictive element (micro-orifice) based on hydrodynamic cavitation were utilized for this purpose. The small bubbly, cavitating, flow generator (micro-orifice) was fitted to a small flexible probe, which was actuated with a micromanipulator using fine control. This probe also houses an imaging device for visualization so that the emerging cavitating flow could be locally targeted to the desired spot. In this study, the feasibility of this alternative treatment method and its integration to a device prototype were successfully accomplished.

Atomic Oxygen Cleaning Shown to Remove Organic Contaminants at Atmospheric Pressure

NASA Technical Reports Server (NTRS)

Rutledge, Sharon K.

1998-01-01

The NASA Lewis Research Center has developed and filed for a patent on a method to produce atomic oxygen at atmospheric pressure by using a direct current arc in a gas flow mixture of oxygen and helium. A prototype device has been tested for its ability to remove various soot residues from surfaces exposed to fire, and various varnishes such as acrylic and egg white.

Intelligent Network Flow Optimization (INFLO) prototype acceptance test summary.

DOT National Transportation Integrated Search

2015-05-01

This report summarizes the results of System Acceptance Testing for the implementation of the Intelligent Network Flow Optimization (INFLO) Prototype bundle within the Dynamic Mobility Applications (DMA) portion of the Connected Vehicle Program. This...

Influence of Coanda surface curvature on performance of bladeless fan

NASA Astrophysics Data System (ADS)

Li, Guoqi; Hu, Yongjun; Jin, Yingzi; Setoguchi, Toshiaki; Kim, Heuy Dong

2014-10-01

The unique Coanda surface has a great influence on the performance of bladeless fan. However, there is few studies to explain the relationship between the performance and Coanda surface curvature at present. In order to gain a qualitative understanding of effect of the curvature on the performance of bladeless fan, numerical studies are performed in this paper. Firstly, three-dimensional numerical simulation is done by Fluent software. For the purpose to obtain detailed information of the flow field around the Coanda surface, two-dimensional numerical simulation is also conducted. Five types of Coanda surfaces with different curvature are designed, and the flow behaviour and the performance of them are analyzed and compared with those of the prototype. The analysis indicates that the curvature of Coanda surface is strongly related to blowing performance, It is found that there is an optimal curvature of Coanda surfaces among the studied models. Simulation result shows that there is a special low pressure region. With increasing curvature in Y direction, several low pressure regions gradually enlarged, then begin to merge slowly, and finally form a large area of low pressure. From the analyses of streamlines and velocity angle, it is found that the magnitude of the curvature affects the flow direction and reasonable curvature can induce fluid flow close to the wall. Thus, it leads to that the curvature of the streamlines is consistent with that of Coanda surface. Meanwhile, it also causes the fluid movement towards the most suitable direction. This study will provide useful information to performance improvements of bladeless fans.

A prototype heat pipe heat exchanger for the capillary pumped loop flight experiment

NASA Technical Reports Server (NTRS)

Ku, Jentung; Yun, Seokgeun; Kroliczek, Edward J.

1992-01-01

A Capillary Pumped Two-Phase Heat Transport Loop (CAPL) Flight Experiment, currently planned for 1993, will provide microgravity verification of the prototype capillary pumped loop (CPL) thermal control system for EOS. CAPL employs a heat pipe heat exchanger (HPHX) to couple the condenser section of the CPL to the radiator assembly. A prototype HPHX consisting of a heat exchanger (HX), a header heat pipe (HHP), a spreader heat pipe (SHP), and a flow regulator has been designed and tested. The HX transmits heat from the CPL condenser to the HHP, while the HHP and SHP transport heat to the radiator assembly. The flow regulator controls flow distribution among multiple parallel HPHX's. Test results indicated that the prototype HPHX could transport up to 800 watts with an overall heat transfer coefficient of more than 6000 watts/sq m-deg C. Flow regulation among parallel HPHX's was also demonstrated.

Molecular transport and flow past hard and soft surfaces: computer simulation of model systems.

PubMed

Léonforte, F; Servantie, J; Pastorino, C; Müller, M

2011-05-11

The equilibrium and flow of polymer films and drops past a surface are characterized by the interface and surface tensions, viscosity, slip length and hydrodynamic boundary position. These parameters of the continuum description are extracted from molecular simulations of coarse-grained models. Hard, corrugated substrates are modelled by a Lennard-Jones solid while polymer brushes are studied as prototypes of soft, deformable surfaces. Four observations are discussed. (i) If the surface becomes strongly attractive or is coated with a brush, the Navier boundary condition fails to describe the effect of the surface independently of the strength and type of the flow. This failure stems from the formation of a boundary layer with an effective, higher viscosity. (ii) In the case of brush-coated surfaces, flow induces a cyclic, tumbling motion of the tethered chain molecules. Their collective motion gives rise to an inversion of the flow in the vicinity of the grafting surfaces and leads to strong, non-Gaussian fluctuations of the molecular orientations. The flow past a polymer brush cannot be described by Brinkman's equation. (iii) The hydrodynamic boundary condition is an important parameter for predicting the motion of polymer droplets on a surface under the influence of an external force. Their steady-state velocity is dictated by a balance between the power that is provided by the external force and the dissipation. If there is slippage at the liquid-solid interface, the friction at the solid-liquid interface and the viscous dissipation of the flow inside the drop will be the dominant dissipation mechanisms; dissipation at the three-phase contact line appears to be less important on a hard surface. (iv) On a soft, deformable substrate like a polymer brush, we observe a lifting-up of the three-phase contact line. Controlling the grafting density and the incompatibility between the brush and the polymer liquid we can independently tune the softness of the surface and the contact angle and thereby identify the parameters for maximizing the deformation at the three-phase contact.

Multiple Flow Loop SCADA System Implemented on the Production Prototype Loop

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baily, Scott A.; Dalmas, Dale Allen; Wheat, Robert Mitchell

2015-11-16

The following report covers FY 15 activities to develop supervisory control and data acquisition (SCADA) system for the Northstar Moly99 production prototype gas flow loop. The goal of this effort is to expand the existing system to include a second flow loop with a larger production-sized blower. Besides testing the larger blower, this system will demonstrate the scalability of our solution to multiple flow loops.

Acoustic metacages for sound shielding with steady air flow

NASA Astrophysics Data System (ADS)

Shen, Chen; Xie, Yangbo; Li, Junfei; Cummer, Steven A.; Jing, Yun

2018-03-01

Conventional sound shielding structures typically prevent fluid transport between the exterior and interior. A design of a two-dimensional acoustic metacage with subwavelength thickness which can shield acoustic waves from all directions while allowing steady fluid flow is presented in this paper. The structure is designed based on acoustic gradient-index metasurfaces composed of open channels and shunted Helmholtz resonators. In-plane sound at an arbitrary angle of incidence is reflected due to the strong parallel momentum on the metacage surface, which leads to low sound transmission through the metacage. The performance of the proposed metacage is verified by numerical simulations and measurements on a three-dimensional printed prototype. The acoustic metacage has potential applications in sound insulation where steady fluid flow is necessary or advantageous.

High-performance, low-voltage electroosmotic pumps with molecularly thin silicon nanomembranes

PubMed Central

Snyder, Jessica L.; Getpreecharsawas, Jirachai; Fang, David Z.; Gaborski, Thomas R.; Striemer, Christopher C.; Fauchet, Philippe M.; Borkholder, David A.; McGrath, James L.

2013-01-01

We have developed electroosmotic pumps (EOPs) fabricated from 15-nm-thick porous nanocrystalline silicon (pnc-Si) membranes. Ultrathin pnc-Si membranes enable high electroosmotic flow per unit voltage. We demonstrate that electroosmosis theory compares well with the observed pnc-Si flow rates. We attribute the high flow rates to high electrical fields present across the 15-nm span of the membrane. Surface modifications, such as plasma oxidation or silanization, can influence the electroosmotic flow rates through pnc-Si membranes by alteration of the zeta potential of the material. A prototype EOP that uses pnc-Si membranes and Ag/AgCl electrodes was shown to pump microliter per minute-range flow through a 0.5-mm-diameter capillary tubing with as low as 250 mV of applied voltage. This silicon-based platform enables straightforward integration of low-voltage, on-chip EOPs into portable microfluidic devices with low back pressures. PMID:24167263

Advantages of using subsurface flow constructed wetlands for wastewater treatment in space applications: Ground-based mars base prototype

NASA Astrophysics Data System (ADS)

Nelson, M.; Alling, A.; Dempster, W. F.; van Thillo, M.; Allen, John

Research and design of subsurface flow wetland wastewater treatment systems for a ground-based experimental prototype Mars Base facility has been carried out, using a subsurface flow approach. These systems have distinct advantages in planetary exploration scenarios: they are odorless, relatively low-labor and low-energy, assist in purification of water and recycling of atmospheric CO2, and will support some food crops. An area of 6-8 m2 may be sufficient for integration of wetland wastewater treatment with a prototype Mars Base supporting 4-5 people. Discharge water from the wetland system will be used as irrigation water for the agricultural crop area, thus ensuring complete recycling and utilization of nutrients. Since the primary requirements for wetland treatment systems are warm temperatures and lighting, such bioregenerative systems may be integrated into early Mars base habitats, since waste heat from the lights may be used for temperature maintenance in the human living environment. "Wastewater gardens ™" can be modified for space habitats to lower space and mass requirements. Many of its construction requirements can eventually be met with use of in-situ materials, such as gravel from the Mars surface. Because the technology requires little machinery and no chemicals, and relies more on natural ecological mechanisms (microbial and plant metabolism), maintenance requirements are minimized, and systems can be expected to have long operating lifetimes. Research needs include suitability of Martian soil and gravel for wetland systems, system sealing and liner options in a Mars Base, and wetland water quality efficiency under varying temperature and light regimes.

Charge-flow structures as polymeric early-warning fire alarm devices. M.S. Thesis; [metal oxide semiconductors

NASA Technical Reports Server (NTRS)

Sechen, C. M.; Senturia, S. D.

1977-01-01

The charge-flow transistor (CFT) and its applications for fire detection and gas sensing were investigated. The utility of various thin film polymers as possible sensing materials was determined. One polymer, PAPA, showed promise as a relative humidity sensor; two others, PFI and PSB, were found to be particularly suitable for fire detection. The behavior of the charge-flow capacitor, which is basically a parallel-plate capacitor with a polymer-filled gap in the metallic tip electrode, was successfully modeled as an RC transmission line. Prototype charge-flow transistors were fabricated and tested. The effective threshold voltage of this metal oxide semiconductor was found to be dependent on whether surface or bulk conduction in the thin film was dominant. Fire tests with a PFI-coated CFT indicate good sensitivity to smouldering fires.

Controlled double emulsification utilizing 3D PDMS microchannels

NASA Astrophysics Data System (ADS)

Chang, Fu-Che; Su, Yu-Chuan

2008-06-01

This paper presents a PDMS emulsification device that is capable of generating water-in-oil-in-water double emulsions in a controlled manner. Specially designed 3D microchannels are utilized to steer the independently driven water- and oil-phase flows (especially to restrict the attachment of the middle oil-phase flow on the channel surfaces), and to break the continuous flows into monodisperse double emulsions. In addition to channel geometries and fluid flow rates, surfactants and osmotic agents are employed to facilitate the breakup process and stabilize the resulting emulsion structures. In the prototype demonstration, two-level SU-8 molds were fabricated to duplicate PDMS microstructures, which were surface treated and bonded irreversibly to form 3D microchannels. Throughout the emulsification trials, dripping was intentionally induced to generate monodisperse double emulsions with single or multiple aqueous droplets inside each oil drop. It is found that the overall and core sizes of the resulting double emulsions could be adjusted independently, mainly by varying the outer and inner fluid flow rates, respectively. As such, the presented double emulsification device could potentially realize the controllability on emulsion structure and size distribution, which is desired for a variety of biological and pharmaceutical applications.

Are anticoagulant independent mechanical valves within reach-fast prototype fabrication and in vitro testing of innovative bi-leaflet valve models.

PubMed

Scotten, Lawrence N; Siegel, Rolland

2015-08-01

Exploration for causes of prosthetic valve thrombogenicity has frequently focused on forward or post-closure flow detail. In prior laboratory studies, we uncovered high amplitude flow velocities of short duration close to valve closure implying potential for substantial shear stress with subsequent initiation of blood coagulation pathways. This may be relevant to widely accepted clinical disparity between mechanical and tissue valves vis-à-vis thrombogenicity. With a series of prototype bi-leaflet mechanical valves, we attempt reduction of closure related velocities with the objective of identifying a prototype valve with thrombogenic potential similar to our tissue valve control. This iterative design approach may find application in preclinical assessment of valves for anticoagulation independence. Tested valves included: prototype mechanical bi-leaflet BVs (n=56), controls (n=2) and patented early prototype mechanicals (n=2) from other investigators. Pulsatile and quasi-steady flow systems were used for testing. Projected dynamic valve area (PDVA) was measured using previously described novel technology. Flow velocity over the open and closing periods was determined by volumetric flow rate/PDVA. For the closed valve interval, use was made of data obtained from quasi-steady back pressure/flow tests. Performance was ranked by a proposed thrombogenicity potential index (TPI) relative to tissue and mechanical control valves. Optimization of the prototype valve designs lead to a 3-D printed model (BV3D). For the mitral/aortic site, BV3D has lower TPI (1.10/1.47) relative to the control mechanical valve (3.44/3.93) and similar to the control tissue valve (ideal TPI ≤1.0). Using unique technology, rapid prototyping and thrombogenicity ranking, optimization of experimental valves for reduced thrombogenic potential was expedited and simplified. Innovative mechanical valve configurations were identified that merit consideration for further development which may bring the anti-coagulation independent mechanical valve within reach.

Are anticoagulant independent mechanical valves within reach—fast prototype fabrication and in vitro testing of innovative bi-leaflet valve models

PubMed Central

Siegel, Rolland

2015-01-01

Background Exploration for causes of prosthetic valve thrombogenicity has frequently focused on forward or post-closure flow detail. In prior laboratory studies, we uncovered high amplitude flow velocities of short duration close to valve closure implying potential for substantial shear stress with subsequent initiation of blood coagulation pathways. This may be relevant to widely accepted clinical disparity between mechanical and tissue valves vis-à-vis thrombogenicity. With a series of prototype bi-leaflet mechanical valves, we attempt reduction of closure related velocities with the objective of identifying a prototype valve with thrombogenic potential similar to our tissue valve control. This iterative design approach may find application in preclinical assessment of valves for anticoagulation independence. Methods Tested valves included: prototype mechanical bi-leaflet BVs (n=56), controls (n=2) and patented early prototype mechanicals (n=2) from other investigators. Pulsatile and quasi-steady flow systems were used for testing. Projected dynamic valve area (PDVA) was measured using previously described novel technology. Flow velocity over the open and closing periods was determined by volumetric flow rate/PDVA. For the closed valve interval, use was made of data obtained from quasi-steady back pressure/flow tests. Performance was ranked by a proposed thrombogenicity potential index (TPI) relative to tissue and mechanical control valves. Results Optimization of the prototype valve designs lead to a 3-D printed model (BV3D). For the mitral/aortic site, BV3D has lower TPI (1.10/1.47) relative to the control mechanical valve (3.44/3.93) and similar to the control tissue valve (ideal TPI ≤1.0). Conclusions Using unique technology, rapid prototyping and thrombogenicity ranking, optimization of experimental valves for reduced thrombogenic potential was expedited and simplified. Innovative mechanical valve configurations were identified that merit consideration for further development which may bring the anti-coagulation independent mechanical valve within reach. PMID:26417581

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ranjan, Devesh

Diffusion bonded heat exchangers are the leading candidates for the sCO 2 Brayton cycles in next generation nuclear power plants. Commercially available diffusion bonded heat exchangers utilize set of continuous semi-circular zigzag micro channels to increase the heat transfer area and enhance heat transfer through increased turbulence production. Such heat exchangers can lead to excessive pressure drop as well as flow maldistribution in the case of poorly designed flow distribution headers. The goal of the current project is to fabricate and test potential discontinuous fin patterns for diffusion bonded heat exchangers; which can achieve desired thermal performance at lower pressuremore » drops. Prototypic discontinuous offset rectangular and Airfoil fin surface geometries were chemically etched on to 316 stainless steel plate and sealed against an un-etched flat pate using O-ring seal emulating diffusion bonded heat exchangers. Thermal-hydraulic performance of these prototypic discontinuous fin geometries was experimentally evaluated and compared to the existing data for the continuous zigzag channels. The data generated from this project will serve as the database for future testing and validation of numerical models.« less

From MIMO-OFDM Algorithms to a Real-Time Wireless Prototype: A Systematic Matlab-to-Hardware Design Flow

NASA Astrophysics Data System (ADS)

Weijers, Jan-Willem; Derudder, Veerle; Janssens, Sven; Petré, Frederik; Bourdoux, André

2006-12-01

To assess the performance of forthcoming 4th generation wireless local area networks, the algorithmic functionality is usually modelled using a high-level mathematical software package, for instance, Matlab. In order to validate the modelling assumptions against the real physical world, the high-level functional model needs to be translated into a prototype. A systematic system design methodology proves very valuable, since it avoids, or, at least reduces, numerous design iterations. In this paper, we propose a novel Matlab-to-hardware design flow, which allows to map the algorithmic functionality onto the target prototyping platform in a systematic and reproducible way. The proposed design flow is partly manual and partly tool assisted. It is shown that the proposed design flow allows to use the same testbench throughout the whole design flow and avoids time-consuming and error-prone intermediate translation steps.

Intelligent Network Flow Optimization (INFLO) prototype : Seattle small-scale demonstration plan.

DOT National Transportation Integrated Search

2015-01-01

This report describes the INFLO Prototype Small-Scale Demonstration to be performed in Seattle Washington. This demonstration is intended to demonstrate that the INFLO Prototype, previously demonstrated in a controlled environment, functions well in ...

Biomimetic Multispiked Connecting Ti-Alloy Scaffold Prototype for Entirely-Cementless Resurfacing Arthroplasty Endoprostheses-Exemplary Results of Implantation of the Ca-P Surface-Modified Scaffold Prototypes in Animal Model and Osteoblast Culture Evaluation.

PubMed

Uklejewski, Ryszard; Rogala, Piotr; Winiecki, Mariusz; Tokłowicz, Renata; Ruszkowski, Piotr; Wołuń-Cholewa, Maria

2016-06-29

We present here-designed, manufactured, and tested by our research team-the Ti-alloy prototype of the multispiked connecting scaffold (MSC-Scaffold) interfacing the components of resurfacing arthroplasty (RA) endoprostheses with bone. The spikes of the MSC-Scaffold prototype mimic the interdigitations of the articular subchondral bone, which is the natural biostructure interfacing the articular cartilage with the periarticular trabecular bone. To enhance the osteoinduction/osteointegration potential of the MSC-Scaffold, the attempts to modify its bone contacting surfaces by the process of electrochemical cathodic deposition of Ca-P was performed with further immersion of the MSC-Scaffold prototypes in SBF in order to transform the amorphous calcium-phosphate coating in hydroxyapatite-like (HA-like) coating. The pilot experimental study of biointegration of unmodified and Ca-P surface-modified MSC-Scaffold prototypes was conducted in an animal model (swine) and in osteoblast cell culture. On the basis of a microscope-histological method the biointegration was proven by the presence of trabeculae in the interspike spaces of the MSC-Scaffold prototype on longitudinal and cross-sections of bone-implant specimens. The percentage of trabeculae in the area between the spikes of specimen containing Ca-P surface modified scaffold prototype observed in microCT reconstructions of the explanted joints was visibly higher than in the case of unmodified MSC-Scaffold prototypes. Significantly higher Alkaline Phosphatase (ALP) activity and the cellular proliferation in the case of Ca-P-modified MSC-Scaffold pre-prototypes, in comparison with unmodified pre-prototypes, was found in osteoblast cell cultures. The obtained results of experimental implantation in an animal model and osteoblast cell culture evaluations of Ca-P surface-modified and non-modified biomimetic MSC-Scaffold prototypes for biomimetic entirely-cementless RA endoprostheses indicate the enhancement of the osteoinduction/osteointegration potential by the Ca-P surface modification of the Ti-alloy MSC-Scaffold prototype. Planned further research on the prototype of this biomimetic MSC-Scaffold for a new generation of RA endoprostheses is also given.

Biomimetic Multispiked Connecting Ti-Alloy Scaffold Prototype for Entirely-Cementless Resurfacing Arthroplasty Endoprostheses—Exemplary Results of Implantation of the Ca-P Surface-Modified Scaffold Prototypes in Animal Model and Osteoblast Culture Evaluation

PubMed Central

Uklejewski, Ryszard; Rogala, Piotr; Winiecki, Mariusz; Tokłowicz, Renata; Ruszkowski, Piotr; Wołuń-Cholewa, Maria

2016-01-01

We present here—designed, manufactured, and tested by our research team—the Ti-alloy prototype of the multispiked connecting scaffold (MSC-Scaffold) interfacing the components of resurfacing arthroplasty (RA) endoprostheses with bone. The spikes of the MSC-Scaffold prototype mimic the interdigitations of the articular subchondral bone, which is the natural biostructure interfacing the articular cartilage with the periarticular trabecular bone. To enhance the osteoinduction/osteointegration potential of the MSC-Scaffold, the attempts to modify its bone contacting surfaces by the process of electrochemical cathodic deposition of Ca-P was performed with further immersion of the MSC-Scaffold prototypes in SBF in order to transform the amorphous calcium-phosphate coating in hydroxyapatite-like (HA-like) coating. The pilot experimental study of biointegration of unmodified and Ca-P surface-modified MSC-Scaffold prototypes was conducted in an animal model (swine) and in osteoblast cell culture. On the basis of a microscope-histological method the biointegration was proven by the presence of trabeculae in the interspike spaces of the MSC-Scaffold prototype on longitudinal and cross-sections of bone-implant specimens. The percentage of trabeculae in the area between the spikes of specimen containing Ca-P surface modified scaffold prototype observed in microCT reconstructions of the explanted joints was visibly higher than in the case of unmodified MSC-Scaffold prototypes. Significantly higher Alkaline Phosphatase (ALP) activity and the cellular proliferation in the case of Ca-P-modified MSC-Scaffold pre-prototypes, in comparison with unmodified pre-prototypes, was found in osteoblast cell cultures. The obtained results of experimental implantation in an animal model and osteoblast cell culture evaluations of Ca-P surface-modified and non-modified biomimetic MSC-Scaffold prototypes for biomimetic entirely-cementless RA endoprostheses indicate the enhancement of the osteoinduction/osteointegration potential by the Ca-P surface modification of the Ti-alloy MSC-Scaffold prototype. Planned further research on the prototype of this biomimetic MSC-Scaffold for a new generation of RA endoprostheses is also given. PMID:28773652

HYDRODYNAMIC SIMULATION OF THE UPPER POTOMAC ESTUARY.

USGS Publications Warehouse

Schaffranck, Raymond W.

1986-01-01

Hydrodynamics of the upper extent of the Potomac Estuary between Indian Head and Morgantown, Md. , are simulated using a two-dimensional model. The model computes water-surface elevations and depth-averaged velocities by numerically integrating finite-difference forms of the equations of mass and momentum conservation using the alternating direction implicit method. The fundamental, non-linear, unsteady-flow equations, upon which the model is formulated, include additional terms to account for Coriolis acceleration and meteorological influences. Preliminary model/prototype data comparisons show agreement to within 9% for tidal flow volumes and phase differences within the measured-data-recording interval. Use of the model to investigate the hydrodynamics and certain aspects of transport within this Potomac Estuary reach is demonstrated. Refs.

Testing of the Multi-Fluid Evaporator Engineering Development Unit

NASA Technical Reports Server (NTRS)

Quinn, Gregory; O'Connor, Ed; Riga, Ken; Anderson, Molly; Westheimer, David

2007-01-01

Hamilton Sundstrand is under contract with the NASA Johnson Space Center to develop a scalable, evaporative heat rejection system called the Multi-Fluid Evaporator (MFE). It is being designed to support the Orion Crew Module and to support future Constellation missions. The MFE would be used from Earth sea level conditions to the vacuum of space. The current Shuttle configuration utilizes an ammonia boiler and flash evaporator system to achieve cooling at all altitudes. The MFE system combines both functions into a single compact package with significant weight reduction and improved freeze-up protection. The heat exchanger core is designed so that radial flow of the evaporant provides increasing surface area to keep the back pressure low. The multiple layer construction of the core allows for efficient scale up to the desired heat rejection rate. The full scale MFE prototype will be constructed with four core sections that, combined with a novel control scheme, manage the risk of freezing the heat exchanger cores. A sub-scale MFE engineering development unit (EDU) has been built, and is identical to one of the four sections of a full scale prototype. The EDU has completed testing at Hamilton Sundstrand. The overall test objective was to determine the thermal performance of the EDU. The first set of tests simulated how each of the four sections of the prototype would perform by varying the chamber pressure, evaporant flow rate, coolant flow rate and coolant temperature. A second set of tests was conducted with an outlet steam header in place to verify that the outlet steam orifices prevent freeze-up in the core while also allowing the desired thermal turn-down ratio. This paper discusses the EDU tests and results.

Advantages of using subsurface flow constructed wetlands for wastewater treatment in space applications: ground-based Mars Base prototype.

PubMed

Nelson, M; Alling, A; Dempster, W F; van Thillo, M; Allen, John

2003-01-01

Research and design of subsurface flow wetland wastewater treatment systems for a ground-based experimental prototype Mars Base facility has been carried out, using a subsurface flow approach. These systems have distinct advantages in planetary exploration scenarios: they are odorless, relatively low-labor and low-energy, assist in purification of water and recycling of atmospheric CO2, and will support some food crops. An area of 6-8 m2 may be sufficient for integration of wetland wastewater treatment with a prototype Mars Base supporting 4-5 people. Discharge water from the wetland system will be used as irrigation water for the agricultural crop area, thus ensuring complete recycling and utilization of nutrients. Since the primary requirements for wetland treatment systems are warm temperatures and lighting, such bioregenerative systems may be integrated into early Mars base habitats, since waste heat from the lights may be used for temperature maintenance in the human living environment. "Wastewater gardens (TM)" can be modified for space habitats to lower space and mass requirements. Many of its construction requirements can eventually be met with use of in-situ materials, such as gravel from the Mars surface. Because the technology requires little machinery and no chemicals, and relies more on natural ecological mechanisms (microbial and plant metabolism), maintenance requirements are minimized, and systems can be expected to have long operating lifetimes. Research needs include suitability of Martian soil and gravel for wetland systems, system sealing and liner options in a Mars Base, and wetland water quality efficiency under varying temperature and light regimes. c2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Rapid prototyping raw models on the basis of high resolution computed tomography lung data for respiratory flow dynamics.

PubMed

Giesel, Frederik L; Mehndiratta, Amit; von Tengg-Kobligk, Hendrik; Schaeffer, A; Teh, Kevin; Hoffman, E A; Kauczor, Hans-Ulrich; van Beek, E J R; Wild, Jim M

2009-04-01

Three-dimensional image reconstruction by volume rendering and rapid prototyping has made it possible to visualize anatomic structures in three dimensions for interventional planning and academic research. Volumetric chest computed tomography was performed on a healthy volunteer. Computed tomographic images of the larger bronchial branches were segmented by an extended three-dimensional region-growing algorithm, converted into a stereolithography file, and used for computer-aided design on a laser sintering machine. The injection of gases for respiratory flow modeling and measurements using magnetic resonance imaging were done on a hollow cast. Manufacturing the rapid prototype took about 40 minutes and included the airway tree from trackea to segmental bronchi (fifth generation). The branching of the airways are clearly visible in the (3)He images, and the radial imaging has the potential to elucidate the airway dimensions. The results for flow patterns in the human bronchial tree using the rapid-prototype model with hyperpolarized helium-3 magnetic resonance imaging show the value of this model for flow phantom studies.

A gas flow indicator for portable life support systems

NASA Technical Reports Server (NTRS)

Bass, R. L., III; Schroeder, E. C.

1975-01-01

A three-part program was conducted to develop a gas flow indicator (GFI) to monitor ventilation flow in a portable life support system. The first program phase identified concepts which could potentially meet the GFI requirements. In the second phase, a working breadboard GFI, based on the concept of a pressure sensing diaphragm-aneroid assembly connected to a venturi, was constructed and tested. Extensive testing of the breadboard GFI indicated that the design would meet all NASA requirements including eliminating problems experienced with the ventilation flow sensor used in the Apollo program. In the third program phase, an optimized GFI was designed by utilizing test data obtained on the breadboard unit. A prototype unit was constructed using prototype materials and fabrication techniques, and performance tests indicated that the prototype GFI met or exceeded all requirements.

Intelligent Network Flow Optimization (INFLO) prototype : Seattle small-scale demonstration report.

DOT National Transportation Integrated Search

2015-05-01

This report describes the performance and results of the INFLO Prototype Small-Scale Demonstration. The purpose of the Small-Scale Demonstration was to deploy the INFLO Prototype System to demonstrate its functionality and performance in an operation...

A novel enhanced diffusion sampler for collecting gaseous pollutants without air agitation.

PubMed

Pan, Xuelian; Zhuo, Shaojie; Zhong, Qirui; Chen, Yuanchen; Du, Wei; Cheng, Hefa; Wang, Xilong; Zeng, Eddy Y; Xing, Baoshan; Tao, Shu

2018-03-06

A novel enhanced diffusion sampler for collecting gaseous phase polycyclic aromatic hydrocarbons (PAHs) without air agitation is proposed. The diffusion of target compounds into a sampling chamber is facilitated by continuously purging through a closed-loop flow to create a large concentration difference between the ambient air and the air in the sampling chamber. A glass-fiber filter-based prototype was developed. It was demonstrated that the device could collect gaseous PAHs at a much higher rate (1.6 ± 1.4 L/min) than regular passive samplers, while the ambient air is not agitated. The prototype was also tested in both the laboratory and field for characterizing the concentration gradients over a short distance from the soil surface. The sampler has potential to be applied in other similar situations to characterize the concentration profiles of other chemicals.

The effect of butterfly-scale inspired patterning on leading-edge vortex growth

NASA Astrophysics Data System (ADS)

Wilroy, Jacob; Lang, Amy; Wahidi, Redha

2014-11-01

Leading edge vortices (LEVs) are important for generating thrust and lift in flapping flight, and the surface patterning (scales) on butterfly wings is hypothesized to play a role in the vortex formation of the LEV. To simplify this complex flow problem, we designed an experiment to focus on the alteration of 2-D vortex development with a variation in surface patterning. Specifically we are interested in the secondary vorticity generated by the LEV interacting at the patterned surface and how this can affect the growth rate of the circulation in the LEV. For this experiment we used rapid-prototyped longitudinal and transverse square grooves attached to a flat plate and compared the vortex formation as the plate moved vertically. The plate is impulsively started in quiescent water and flow fields at Re = 1500, 3000, and 6000 are examined using Digital Particle Image Velocimetry (DPIV). The vortex formation time is 0.6 and is based on the flat plate travel length and chord length. Support for this research came from NSF REU Grant 1358991 and CBET 1335848.

Joint NOAA/NWS/USGS prototype debris flow warning system for recently burned areas in Southern California

USGS Publications Warehouse

Restrepo, P.; Jorgensen, D.P.; Cannon, S.H.; Costa, J.; Laber, J.; Major, J.; Martner, B.; Purpura, J.; Werner, K.

2008-01-01

Debris flows, also known as mudslides, are composed gravity-driven mixtures of sediment and water that travel through steep channels, over open hillslopes, and the like. Addressing this issue, US Geological Survey (USGS) and NOAA have established a debris-flow warning system that has the ability to monitor and forecast precipitation and issue timely weather hazard warning. In 2005, this joint NOAA-USGS prototype debris-flow warning system was issued in Southern California and as a result, it has provided valuable information to emergency managers in affected communities.

The design and fabrication of two portal vein flow phantoms by different methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yunker, Bryan E., E-mail: bryan.yunker@ucdenver.edu; Lanning, Craig J.; Shandas, Robin

2014-02-15

Purpose: This study outlines the design and fabrication techniques for two portal vein flow phantoms. Methods: A materials study was performed as a precursor to this phantom fabrication effort and the desired material properties are restated for continuity. A three-dimensional portal vein pattern was created from the Visual Human database. The portal vein pattern was used to fabricate two flow phantoms by different methods with identical interior surface geometry using computer aided design software tools and rapid prototyping techniques. One portal flow phantom was fabricated within a solid block of clear silicone for use on a table with Ultrasound ormore » within medical imaging systems such as MRI, CT, PET, or SPECT. The other portal flow phantom was fabricated as a thin walled tubular latex structure for use in water tanks with Ultrasound imaging. Both phantoms were evaluated for usability and durability. Results: Both phantoms were fabricated successfully and passed durability criteria for flow testing in the next project phase. Conclusions: The fabrication methods and materials employed for the study yielded durable portal vein phantoms.« less

Proteomic Identification of Immunodiagnostic Antigens for Trypanosoma vivax Infections in Cattle and Generation of a Proof-of-Concept Lateral Flow Test Diagnostic Device.

PubMed

Fleming, Jennifer R; Sastry, Lalitha; Wall, Steven J; Sullivan, Lauren; Ferguson, Michael A J

2016-09-01

Trypanosoma vivax is one of the causative agents of Animal African Trypanosomosis in cattle, which is endemic in sub-Saharan Africa and transmitted primarily by the bite of the tsetse fly vector. The parasite can also be mechanically transmitted, and this has allowed its spread to South America. Diagnostics are limited for this parasite and in farm settings diagnosis is mainly symptom-based. We set out to identify, using a proteomic approach, candidate diagnostic antigens to develop into an easy to use pen-side lateral flow test device. Two related members the invariant surface glycoprotein family, TvY486_0045500 and TvY486_0019690, were selected. Segments of these antigens, lacking N-terminal signal peptides and C-terminal transmembrane domains, were expressed in E. coli. Both were developed into ELISA tests and one of them, TvY486_0045500, was developed into a lateral flow test prototype. The tests were all evaluated blind with 113 randomised serum samples, taken from 37 calves before and after infection with T. vivax or T. congolense. The TvY486_0045500 and TvY486_0019690 ELISA tests gave identical sensitivity and specificity values for T. vivax infection of 94.5% (95% CI, 86.5% to 98.5%) and 88.0% (95% CI, 75.7% to 95.5%), respectively, and the TvY486_0045500 lateral flow test prototype a sensitivity and specificity of 92.0% (95% CI, 83.4% to 97.0%) and 89.8% (95% CI, 77.8% to 96.6%), respectively. These data suggest that recombinant TvY486_0045500 shows promise for the development of a pen-side lateral flow test for the diagnosis of T. vivax animal African trypanosomosis.

Prototyping of Poly(dimethylsiloxane) Interfaces for Flow Gating, Reagent Mixing, and Tubing Connection in Capillary Electrophoresis

PubMed Central

Zhang, Qiyang; Gong, Maojun

2014-01-01

Integrated microfluidic systems coupled with electrophoretic separations have broad application in biological and chemical analysis. Interfaces for the connection of various functional parts play a major role in the performance of a system. Here we developed a rapid prototyping method to fabricate monolithic poly(dimethylsiloxane) (PDMS) Interfaces for flow-gated injection, online reagent mixing, and tube-to-tube connection in an integrated capillary electrophoresis (CE) system. The basic idea was based on the properties of PDMS: elasticity, transparency, and suitability for prototyping. The molds for these interfaces were prepared by using commercially available stainless steel wires and nylon lines or silica capillaries. A steel wire was inserted through the diameter of a nylon line and a cross format was obtained as the mold for PDMS casting of flow gates and 4-way mixers. These interfaces accommodated tubing connection through PDMS elasticity and provided easy visual trouble shooting. The flow gate used smaller channel diameters thus reducing flow rate by 25 fold for effective gating compared with mechanically machined counterparts. Both PDMS mixers and the tube-to-tube connectors could minimize the sample dead volume by using an appropriate capillary configuration. As a whole, the prototyped PDMS interfaces are reusable, inexpensive, convenient for connection, and robust when integrated with the CE detection system. Therefore, these interfaces could see potential applications in CE and CE-coupled systems. PMID:24331370

Prototypal Course in Newspaper Mangement: A Systems Analysis Approach to Teaching the Economic Context of Press Freedom in Modern Society.

ERIC Educational Resources Information Center

DeMott, John

The prototypal course in newspaper management described in this paper is based on systems analysis and the systems flow approach. The introductory section of the paper discusses the need for instruction in newspaper management, the concepts of the systems approach and systems flow and the way they relate to enterprise management, and specific…

Rapid prototyping polymers for microfluidic devices and high pressure injections.

PubMed

Sollier, Elodie; Murray, Coleman; Maoddi, Pietro; Di Carlo, Dino

2011-11-21

Multiple methods of fabrication exist for microfluidic devices, with different advantages depending on the end goal of industrial mass production or rapid prototyping for the research laboratory. Polydimethylsiloxane (PDMS) has been the mainstay for rapid prototyping in the academic microfluidics community, because of its low cost, robustness and straightforward fabrication, which are particularly advantageous in the exploratory stages of research. However, despite its many advantages and its broad use in academic laboratories, its low elastic modulus becomes a significant issue for high pressure operation as it leads to a large alteration of channel geometry. Among other consequences, such deformation makes it difficult to accurately predict the flow rates in complex microfluidic networks, change flow speed quickly for applications in stop-flow lithography, or to have predictable inertial focusing positions for cytometry applications where an accurate alignment of the optical system is critical. Recently, other polymers have been identified as complementary to PDMS, with similar fabrication procedures being characteristic of rapid prototyping but with higher rigidity and better resistance to solvents; Thermoset Polyester (TPE), Polyurethane Methacrylate (PUMA) and Norland Adhesive 81 (NOA81). In this review, we assess these different polymer alternatives to PDMS for rapid prototyping, especially in view of high pressure injections with the specific example of inertial flow conditions. These materials are compared to PDMS, for which magnitudes of deformation and dynamic characteristics are also characterized. We provide a complete and systematic analysis of these materials with side-by-side experiments conducted in our lab that also evaluate other properties, such as biocompatibility, solvent compatibility, and ease of fabrication. We emphasize that these polymer alternatives, TPE, PUMA and NOA, have some considerable strengths for rapid prototyping when bond strength, predictable operation at high pressure, or transitioning to commercialization are considered important for the application.

Motion of Deformable Drops Through Porous Media

NASA Astrophysics Data System (ADS)

Zinchenko, Alexander Z.; Davis, Robert H.

2017-01-01

This review describes recent progress in the fundamental understanding of deformable drop motion through porous media with well-defined microstructures, through rigorous first-principles hydrodynamical simulations and experiments. Tight squeezing conditions, when the drops are much larger than the pore throats, are particularly challenging numerically, as the drops nearly coat the porous material skeleton with small surface clearance, requiring very high surface resolution in the algorithms. Small-scale prototype problems for flow-induced drop motion through round capillaries and three-dimensional (3D) constrictions between solid particles, and for gravity-induced squeezing through round orifices and 3D constrictions, show how forcing above critical conditions is needed to overcome trapping. Scaling laws for the squeezing time are suggested. Large-scale multidrop/multiparticle simulations for emulsion flow through a random granular material with multiple drop breakup show that the drop phase generally moves faster than the carrier fluid; both phase velocities equilibrate much faster to the statistical steady state than does the drop-size distribution.

Study on the thermodynamical and mechanical conditions for the generation of high operating pressures with liquefied gases for low and very low flow rates

NASA Astrophysics Data System (ADS)

Nieratschker, Willi

1989-12-01

An investigation of the thermodynamical and mechanical conditions for extending the flow rate range in the direction of low flow rates with regard to the delivery of liquefied gases at high operating pressures is presented. For low flow rates, the especially critical cavitation problem connected with the pumping of liquefied gases becomes more acute, since with decreasing volume the ratio of heat losses to the hydraulic power becomes ever more unfavorable. A first prototype is designed, produced and investigated to evaluate design-related heat loss and piston seal problems. An approach to the solution is indicated for both problem areas with the application of a new and patented pump principle, and through investigation of a second prototype modified in several respects. By reducing the pump mass when designing the second pump prototype, the nonstationary cooling phase is greatly shortened, so that intermittent pump operation becomes possible when the pump is housed external to the storage tank.

Study and development of an air conditioning system operating on a magnetic heat pump cycle (design and testing of flow directors)

NASA Astrophysics Data System (ADS)

Wang, Pao-Lien

1992-09-01

This report describes the fabrication, design of flow director, fluid flow direction analysis and testing of flow director of a magnetic heat pump. The objectives of the project are: (1) to fabricate a demonstration magnetic heat pump prototype with flow directors installed; and (2) analysis and testing of flow director and to make sure working fluid loops flow through correct directions with minor mixing. The prototype was fabricated and tested at the Development Testing Laboratory of Kennedy Space Center. The magnetic heat pump uses rear earth metal plates rotate in and out of a magnetic field in a clear plastic housing with water flowing through the rotor plates to provide temperature lift. Obtaining the proper water flow direction has been a problem. Flow directors were installed as flow barriers between separating point of two parallel loops. Function of flow directors were proven to be excellent both analytically and experimentally.

Study and development of an air conditioning system operating on a magnetic heat pump cycle (design and testing of flow directors)

NASA Technical Reports Server (NTRS)

Wang, Pao-Lien

1992-01-01

This report describes the fabrication, design of flow director, fluid flow direction analysis and testing of flow director of a magnetic heat pump. The objectives of the project are: (1) to fabricate a demonstration magnetic heat pump prototype with flow directors installed; and (2) analysis and testing of flow director and to make sure working fluid loops flow through correct directions with minor mixing. The prototype was fabricated and tested at the Development Testing Laboratory of Kennedy Space Center. The magnetic heat pump uses rear earth metal plates rotate in and out of a magnetic field in a clear plastic housing with water flowing through the rotor plates to provide temperature lift. Obtaining the proper water flow direction has been a problem. Flow directors were installed as flow barriers between separating point of two parallel loops. Function of flow directors were proven to be excellent both analytically and experimentally.

Survey of shock-wave structures of smooth-particle granular flows.

PubMed

Padgett, D A; Mazzoleni, A P; Faw, S D

2015-12-01

We show the effects of simulated supersonic granular flow made up of smooth particles passing over two prototypical bodies: a wedge and a disk. We describe a way of computationally identifying shock wave locations in granular flows and tabulate the shock wave locations for flow over wedges and disks. We quantify the shock structure in terms of oblique shock angle for wedge impediments and shock standoff distance for disk impediments. We vary granular flow parameters including upstream volume fraction, average upstream velocity, granular temperature, and the collision coefficient of restitution. Both wedges and disks have been used in the aerospace community as prototypical impediments to flowing air in order to investigate the fundamentally different shock structures emanating from sharp and blunt bodies, and we present these results in order to increase the understanding of the fundamental behavior of supersonic granular flow.

Prototype continuous flow ventricular assist device supported on magnetic bearings.

PubMed

Allaire, P E; Kim, H C; Maslen, E H; Olsen, D B; Bearnson, G B

1996-06-01

This article describes a prototype continuous flow pump (CFVAD2) fully supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. The pump delivered 6 L/min of flow at 100 mm Hg of differential pressure head operating at 2,400 rpm in water. The pump is totally supported in 4 magnetic bearings: 2 radial and 2 thrust. Magnetic bearings offer the advantages of no required lubrication and large operating clearances. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity and current gains are discussed. Bearing coil currents were measured during operation in air and water. The rotor was operated in various orientations to determine the actuator current gains. These values were then used to estimate the radial and thrust forces acting on the rotor in both air and water. Much lower levels of force were found than were expected, allowing for a very significant reduction in the size of the next prototype. Hemolysis levels were measured in the prototype pump and found not to indicate damage to the blood cells.

Improving flow distribution in influent channels using computational fluid dynamics.

PubMed

Park, No-Suk; Yoon, Sukmin; Jeong, Woochang; Lee, Seungjae

2016-10-01

Although the flow distribution in an influent channel where the inflow is split into each treatment process in a wastewater treatment plant greatly affects the efficiency of the process, and a weir is the typical structure for the flow distribution, to the authors' knowledge, there is a paucity of research on the flow distribution in an open channel with a weir. In this study, the influent channel of a real-scale wastewater treatment plant was used, installing a suppressed rectangular weir that has a horizontal crest to cross the full channel width. The flow distribution in the influent channel was analyzed using a validated computational fluid dynamics model to investigate (1) the comparison of single-phase and two-phase simulation, (2) the improved procedure of the prototype channel, and (3) the effect of the inflow rate on flow distribution. The results show that two-phase simulation is more reliable due to the description of the free-surface fluctuations. It should first be considered for improving flow distribution to prevent a short-circuit flow, and the difference in the kinetic energy with the inflow rate makes flow distribution trends different. The authors believe that this case study is helpful for improving flow distribution in an influent channel.

Airspace Technology Demonstration 2 (ATD-2) Phase 1 Concept of Use (ConUse)

NASA Technical Reports Server (NTRS)

Jung, Yoon; Engelland, Shawn; Capps, Richard; Coppenbarger, Rich; Hooey, Becky; Sharma, Shivanjli; Stevens, Lindsay; Verma, Savita; Lohr, Gary; Chevalley, Eric;

Velocity profile, water-surface slope, and bed-material size for selected streams in Colorado

USGS Publications Warehouse

Marchand, J.P.; Jarrett, R.D.; Jones, L.L.

1984-01-01

Existing methods for determining the mean velocity in a vertical sampling section do not address the conditions present in high-gradient, shallow-depth streams common to mountainous regions such as Colorado. The report presents velocity-profile data that were collected for 11 streamflow-gaging stations in Colorado using both a standard Price type AA current meter and a prototype Price Model PAA current meter. Computational results are compiled that will enable mean velocities calculated from measurements by the two current meters to be compared with each other and with existing methods for determining mean velocity. Water-surface slope, bed-material size, and flow-characteristic data for the 11 sites studied also are presented. (USGS)

3D MR flow analysis in realistic rapid-prototyping model systems of the thoracic aorta: comparison with in vivo data and computational fluid dynamics in identical vessel geometries.

PubMed

Canstein, C; Cachot, P; Faust, A; Stalder, A F; Bock, J; Frydrychowicz, A; Küffer, J; Hennig, J; Markl, M

2008-03-01

The knowledge of local vascular anatomy and function in the human body is of high interest for the diagnosis and treatment of cardiovascular disease. A comprehensive analysis of the hemodynamics in the thoracic aorta is presented based on the integration of flow-sensitive 4D MRI with state-of-the-art rapid prototyping technology and computational fluid dynamics (CFD). Rapid prototyping was used to transform aortic geometries as measured by contrast-enhanced MR angiography into realistic vascular models with large anatomical coverage. Integration into a flow circuit with patient-specific pulsatile in-flow conditions and application of flow-sensitive 4D MRI permitted detailed analysis of local and global 3D flow dynamics in a realistic vascular geometry. Visualization of characteristic 3D flow patterns and quantitative comparisons of the in vitro experiments with in vivo data and CFD simulations in identical vascular geometries were performed to evaluate the accuracy of vascular model systems. The results indicate the potential of such patient-specific model systems for detailed experimental simulation of realistic vascular hemodynamics. Further studies are warranted to examine the influence of refined boundary conditions of the human circulatory system such as fluid-wall interaction and their effect on normal and pathological blood flow characteristics associated with vascular geometry. (c) 2008 Wiley-Liss, Inc.

Design and fabrication of prototype system for early warning of impending bearing failure

NASA Technical Reports Server (NTRS)

Broderick, J. J.; Burchill, R. F.; Clark, H. L.

1972-01-01

Ball bearing performance tests run on several identical ball bearings under a variety of load, speed, temperature, and lubrication conditions are reported. Bearing temperature, torque, vibration, noise, strain, cage speed, etc., were monitored to establish those measurements most suitable as indicators of ball bearing health. Tape records were made under steady-state conditions of a variety of speeds and loads. Sample sections were selected for narrowband spectral analysis with a real time analyzer. An artificial flow was created across the inner race surface of one bearing using an acid etch technique to produce the scratch. Tape records obtained before and after established a characteristic frequency response that identifies the presence of the flow. The signals found most useful as indicators of performance degradation were ultrasonic outputs.

Report on architecture description for the INFLO prototype.

DOT National Transportation Integrated Search

2014-01-01

This report documents the Architecture Description for the implementation of the Intelligent Network Flow Optimization (INFLO) Prototype bundle within the Dynamic Mobility Applications (DMA) portion of the Connected Vehicle Program. The intent is to ...

Thermal Analysis of the PediaFlow pediatric ventricular assist device.

PubMed

Gardiner, Jeffrey M; Wu, Jingchun; Noh, Myounggyu D; Antaki, James F; Snyder, Trevor A; Paden, David B; Paden, Brad E

2007-01-01

Accurate modeling of heat dissipation in pediatric intracorporeal devices is crucial in avoiding tissue and blood thermotrauma. Thermal models of new Maglev ventricular assist device (VAD) concepts for the PediaFlow VAD are developed by incorporating empirical heat transfer equations with thermal finite element analysis (FEA). The models assume three main sources of waste heat generation: copper motor windings, active magnetic thrust bearing windings, and eddy currents generated within the titanium housing due to the two-pole motor. Waste heat leaves the pump by convection into blood passing through the pump and conduction through surrounding tissue. Coefficients of convection are calculated and assigned locally along fluid path surfaces of the three-dimensional pump housing model. FEA thermal analysis yields a three-dimensional temperature distribution for each of the three candidate pump models. Thermal impedances from the motor and thrust bearing windings to tissue and blood contacting surfaces are estimated based on maximum temperature rise at respective surfaces. A new updated model for the chosen pump topology is created incorporating computational fluid dynamics with empirical fluid and heat transfer equations. This model represents the final geometry of the first generation prototype, incorporates eddy current heating, and has 60 discrete convection regions. Thermal analysis is performed at nominal and maximum flow rates, and temperature distributions are plotted. Results suggest that the pump will not exceed a temperature rise of 2 degrees C during normal operation.

Flow measurements in a water tunnel using a holocinematographic velocimeter

NASA Technical Reports Server (NTRS)

Weinstein, Leonard M.; Beeler, George B.

1987-01-01

Dual-view holographic movies were used to examine complex flows with full three-space and time resolution. This approach, which tracks the movement of small tracer particles in water, is termed holocinematographic velocimetry (HCV). A small prototype of a new water tunnel was used to demonstrate proof-of-concept for the HCV. After utilizing a conventional flow visualization apparatus with a laser light sheet to illuminate tracer particles to evaluate flow quality of the prototype tunnel, a simplified version of the HCV was employed to demonstrate the capabilities of the approach. Results indicate that a full-scale version of the water tunnel and a high performance version of the HCV should be able to check theoretical and numerical modeling of complex flows and examine the mechanisms operative in turbulent and vortex flow control concepts, providing an entirely unique instrument capable, for the first time, of simultaneous three-space and time measurements in turbulent flow.

The effect of butterfly-scale inspired patterning on leading-edge vortex growth

NASA Astrophysics Data System (ADS)

Wilroy, Jacob Aaron

Leading edge vortices (LEVs) are important for generating thrust and lift in flapping flight, and the surface patterning (scales) on butterfly wings is hypothesized to play a role in the vortex formation of the LEV. To simplify this complex flow problem, an experiment was designed to focus on the alteration of 2-D vortex development with a variation in surface patterning. Specifically, the secondary vorticity generated by the LEV interacting at the patterned surface was studied, as well as the subsequent effect on the LEV's growth rate and peak circulation. For this experiment, rapid-prototyped grooves based on the scale geometry of the Monarch butterfly (Danaus plexippus) were created using additive manufacturing and were attached to a flat plate with a chordwise orientation, thus increasing plate surface area. The vortex generated by the grooved plate was then compared to a smooth plate case in an experiment where the plate translated vertically through a 2 x 3 x 5 cubic foot tow tank. The plate was impulsively started in quiescent water and flow fields at Rec = 1416, 2833, and 5667 are examined using Digital Particle Image Velocimetry (DPIV). The maximum vortex formation number is 2.8 and is based on the flat plate travel length and chord length. Flow fields from each case show the generation of a secondary vortex whose interaction with the shear layer and LEV caused different behaviors depending upon the surface type. The vortex development process varied for each Reynolds number and it was found that for the lowest Reynolds number case a significant difference does not exist between surface types, however, for the other two cases the grooves affected the secondary vortex's behavior and the LEV's ability to grow at a rate similar to the smooth plate case.

On the Effect of Rigid Swept Surface Waves on Turbulent Drag

NASA Technical Reports Server (NTRS)

Denison, M.; Wilkinson, S. P.; Balakumar, P.

2015-01-01

Passive turbulent drag reduction techniques are of interest as a cost effective means to improve air vehicle fuel consumption. In the past, rigid surface waves slanted at an angle from the streamwise direction were deemed ineffective to reduce skin friction drag due to the pressure drag that they generate. A recent analysis seeking similarities to the spanwise shear stress generated by spatial Stokes layers suggested that there may be a range of wavelength, amplitude, and orientation in which the wavy surface would reduce turbulent drag. The present work explores, by experiments and Direct Numerical Simulations (DNS), the effect of swept wavy surfaces on skin friction and pressure drag. Plates with shallow and deep wave patterns were rapid-prototyped and tested using a drag balance in the 7x11 inch Low-Speed Wind Tunnel at the NASA LaRC Research Center. The measured drag o set between the wavy plates and the reference at plate is found to be within the experimental repeatability limit. Oil vapor flow measurements indicate a mean spanwise flow over the deep waves. The turbulent flow in channels with at walls, swept wavy walls and spatial Stokes spanwise velocity forcing was simulated at a friction Reynolds number of two hundred. The time-averaged and dynamic turbulent flow characteristics of the three channel types are compared. The drag obtained for the channel with shallow waves is slightly larger than for the at channel, within the range of the experiments. In the case of the large waves, the simulation over predicts the drag. The shortcomings of the Stokes layer analogy model for the estimation of the spanwise shear stress and drag are discussed.

Raman spectroscopic instrumentation and plasmonic methods for material characterization

NASA Astrophysics Data System (ADS)

Tanaka, Kazuki

The advent of nanotechnology has led to incredible growth in how we consume, make and approach advanced materials. By exploiting nanoscale material properties, unique control of optical, thermal, mechanical, and electrical characteristics becomes possible. This thesis describes the development of a novel localized surface plasmon resonant (LSPR) color sensitive photosensor, based on functionalization of gold nanoparticles onto tianium dioxide nanowires and sensing by a metal-semiconducting nanowire-metal photodiode structure. This LSPR photosensor has been integrated into a system that incorporates Raman spectroscopy, microfluidics, optical trapping, and sorting flow cytometry into a unique material characterization system called the microfluidic optical fiber trapping Raman sorting flow cytometer (MOFTRSFC). Raman spectroscopy is utilized as a powerful molecular characterization technique used to analyze biological, mineralogical and nanomaterial samples. To combat the inherently weak Raman signal, plasmonic methods have been applied to exploit surface enhanced Raman scattering (SERS) and localized surface plasmon resonance (LSPR), increasing Raman intensity by up to 5 orders of magnitude. The resultant MOFTRSFC system is a prototype instrument that can effectively trap, analyze, and sort micron-sized dielectric particles and biological cells. Raman spectroscopy has been presented in several modalities, including the development of a portable near-infrared Raman spectrometer and other emerging technologies.

Pressure pulsation in Kaplan turbines: Prototype-CFD comparison

NASA Astrophysics Data System (ADS)

Rivetti, A.; Lucino1, C.; Liscia, S.; Muguerza, D.; Avellan, F.

2012-11-01

Pressure pulsation phenomena in a large Kaplan turbine are investigated by means of numerical simulations (CFD) and prototype measurements in order to study the dynamic behavior of flow due to the blade passage and its interaction with other components of the turbine. Numerical simulations are performed with the commercial software Ansys CFX code, solving the incompressible Unsteady Reynolds-Averaged-Navier Stokes equations under a finite volume scheme. The computational domain involves the entire machine at prototype scale. Special care is taken in the discretization of the wicket gate overhang and runner blade gap. Prototype measurements are performed using pressure transducers at different locations among the wicket gate outlet and the draft tube inlet. Then, CFD results are compared with temporary signals of prototype measurements at identical locations to validate the numerical model. A detailed analysis was focused on the tip gap flow and the pressure field at the discharge ring. From a rotating reference frame perspective, it is found that the mean pressure fluctuates accordingly the wicket gate passage. Moreover, in prototype measurements the pressure frequency that reveals the presence of modulated cavitation at the discharge ring is distinguished, as also verified from the shape of erosion patches in concordance with the number of wicket gates.

System design document for the INFLO prototype.

DOT National Transportation Integrated Search

2014-03-01

This report documents the high level System Design Document (SDD) for the prototype development and demonstration of the Intelligent Network Flow Optimization (INFLO) application bundle, with a focus on the Speed Harmonization (SPD-HARM) and Queue Wa...

Report on detailed requirements for the INFLO prototype.

DOT National Transportation Integrated Search

2013-12-01

This report documents the System Requirements for the implementation of the Intelligent Network Flow Optimization (INFLO) Prototype bundle within the Dynamic Mobility Applications (DMA) portion of the Connected Vehicle Program. It builds off of the p...

A novel low profile wireless flow sensor to monitor hemodynamic changes in cerebral aneurysm

NASA Astrophysics Data System (ADS)

Chen, Yanfei; Jankowitz, Brian T.; Cho, Sung Kwon; Chun, Youngjae

2015-03-01

A proof of concept of low-profile flow sensor has been designed, fabricated, and subsequently tested to demonstrate its feasibility for monitoring hemodynamic changes in cerebral aneurysm. The prototype sensor contains three layers, i.e., a thin polyurethane layer was sandwiched between two sputter-deposited thin film nitinol layers (6μm thick). A novel superhydrophilic surface treatment was used to create hemocompatible surface of thin nitinol electrode layers. A finite element model was conducted using ANSYS Workbench 15.0 Static Structural to optimize the dimensions of flow sensor. A computational fluid dynamics calculations were performed using ANSYS Workbench Fluent to assess the flow velocity patterns within the aneurysm sac. We built a test platform with a z-axis translation stage and an S-beam load cell to compare the capacitance changes of the sensors with different parameters during deformation. Both LCR meter and oscilloscope were used to measure the capacitance and the resonant frequency shifts, respectively. The experimental compression tests demonstrated the linear relationship between the capacitance and applied compression force and decreasing the length, width and increasing the thickness improved the sensor sensitivity. The experimentally measured resonant frequency dropped from 12.7MHz to 12.48MHz, indicating a 0.22MHz shift with 200g ( 2N) compression force while the theoretical resonant frequency shifted 0.35MHz with 50g ( 0.5N). Our recent results demonstrated a feasibility of the low-profile flow sensor for monitoring haemodynamics in cerebral aneurysm region, as well as the efficacy of the use of the surface treated thin film nitinol for the low-profile sensor materials.

Experimental Study of Two Phase Flow Behavior Past BWR Spacer Grids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ratnayake, Ruwan K.; Hochreiter, L.E.; Ivanov, K.N.

2002-07-01

Performance of best estimate codes used in the nuclear industry can be significantly improved by reducing the empiricism embedded in their constitutive models. Spacer grids have been found to have an important impact on the maximum allowable Critical Heat Flux within the fuel assembly of a nuclear reactor core. Therefore, incorporation of suitable spacer grids models can improve the critical heat flux prediction capability of best estimate codes. Realistic modeling of entrainment behavior of spacer grids requires understanding the different mechanisms that are involved. Since visual information pertaining to the entrainment behavior of spacer grids cannot possibly be obtained frommore » operating nuclear reactors, experiments have to be designed and conducted for this specific purpose. Most of the spacer grid experiments available in literature have been designed in view of obtaining quantitative data for the purpose of developing or modifying empirical formulations for heat transfer, critical heat flux or pressure drop. Very few experiments have been designed to provide fundamental information which can be used to understand spacer grid effects and phenomena involved in two phase flow. Air-water experiments were conducted to obtain visual information on the two-phase flow behavior both upstream and downstream of Boiling Water Reactor (BWR) spacer grids. The test section was designed and constructed using prototypic dimensions such as the channel cross-section, rod diameter and other spacer grid configurations of a typical BWR fuel assembly. The test section models the flow behavior in two adjacent sub channels in the BWR core. A portion of a prototypic BWR spacer grid accounting for two adjacent channels was used with industrial mild steel rods for the purpose of representing the channel internals. Symmetry was preserved in this practice, so that the channel walls could effectively be considered as the channel boundaries. Thin films were established on the rod surfaces by injecting water through a set of perforations at the bottom ends of the rods, ensuring that the flow upstream of the bottom-most spacer grid is predominantly annular. The flow conditions were regulated such that they represent typical BWR operating conditions. Photographs taken during experiments show that the film entrainment increases significantly at the spacer grids, since the points of contact between the rods and the grids result in a peeling off of large portions of the liquid film from the rod surfaces. Decreasing the water flow resulted in eventual drying out, beginning at positions immediately upstream of the spacer grids. (authors)« less

Ventricular Assist Device implant (AB 5000) prototype cannula: In vitro assessment of MRI issues at 3-Tesla

PubMed Central

Shellock, Frank G; Valencerina, Samuel

2008-01-01

Purpose To evaluate MRI issues at 3-Tesla for a ventricular assist device (VAD). Methods The AB5000 Ventricle with a prototype Nitinol wire-reinforced In-Flow Cannula and Out-Flow Cannula attached (Abiomed, Inc., Danvers, MA) was evaluated for magnetic field interactions, heating, and artifacts at 3-Tesla. MRI-related heating was assessed with the device in a gelled-saline-filled, head/torso phantom using a transmit/received RF body coil while performing MRI at a whole body averaged SAR of 3-W/kg for 15-min. Artifacts were assessed for the main metallic component of this VAD (atrial cannula) using T1-weighted, spin echo and gradient echo pulse sequences. Results The AB5000 Ventricle with the prototype In-Flow Cannula and Out-Flow Cannula attached showed relatively minor magnetic field interactions that will not cause movement in situ. Heating was not excessive (highest temperature change, +0.8°C). Artifacts may create issues for diagnostic imaging if the area of interest is in the same area or close to the implanted metallic component of this VAD (i.e., the venous cannula). Conclusion The results of this investigation demonstrated that it would be acceptable for a patient with this VAD (AB5000 Ventricle with a prototype Nitinol wire-reinforced In-Flow Cannula and Out-Flow Cannula attached) to undergo MRI at 3-Tesla or less. Notably, it is likely that the operation console for this device requires positioning a suitable distance (beyond the 100 Gauss line or in the MR control room) from the 3-Tesla MR system to ensure proper function of the VAD. PMID:18495028

Prototype Continuous Flow Ventricular Assist Device Supported on Magnetic Bearings.

PubMed

Allaire, P E; Kim, H C; Maslen, E H; Olsen, D B; Bearnson, G B

1996-05-01

This article describes a prototype continuous flow pump (CFVAD2) fully supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. The pump delivered 6 L/min of flow at 100 mm Hg of differential pressure head operating at 2,400 rpm in water. The pump is totally supported in 4 magnetic bearings: 2 radial and 2 thrust. Magnetic bearings offer the advantages of no required lubrication and large operating clearances. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity and current gains are discussed. Bearing coil currents were measured during operation in air and water. The rotor was operated in various orientations to determine the actuator current gains. These values were then used to estimate the radial and thrust forces acting on the rotor in both air and water. Much lower levels of force were found than were expected, allowing for a very significant reduction in the size of the next prototype. Hemolysis levels were measured in the prototype pump and found not to indicate damage to the blood cells. © 1996 International Society for Artificial Organs.

Cost Effective Prototyping

NASA Technical Reports Server (NTRS)

Wickman, Jerry L.; Kundu, Nikhil K.

1996-01-01

This laboratory exercise seeks to develop a cost effective prototype development. The exercise has the potential of linking part design, CAD, mold development, quality control, metrology, mold flow, materials testing, fixture design, automation, limited parts production and other issues as related to plastics manufacturing.

Self-organization of magnetic particles at fluid interfaces

NASA Astrophysics Data System (ADS)

Belkin, Maxim

Understanding principles that govern emergent behavior in systems with complex interactions has puzzled scientists for many years. In my work I studied seemingly simple but highly non-trivial system of magnetic micro-particles suspended at fluid interface and energized by an external vertical AC magnetic field. It can be considered as a prototype for probing the interplay of individual interactions on the collective response of system to the external driving. The first part of this work is focused on experimental study of self-organization in this system. In a certain region of parameters formation of localized snake-like structures with accompanying large-scale symmetric surface flows is observed. Characteristics of the self-organized structure as well as flows strongly depend on parameters of the external driving. Increased driving leads to a spontaneous symmetry breaking of the surface flows which results in a self-propulsion of the "snake". This observation leads to an idea of controlled design of a self-propelled swimmer. Numerical calculations based on a phenomenological model proposed for the description of such system successfully reproduces self-organization of the snake-like structures, self-propulsion under spontaneous and artificial symmetry breaking. Increase in the number of the particles promotes a formation of multiple snakes which are in turn unstable with respect to self-induced flows and become mobile swimmers. Such ensemble effectively mixes the surface of liquid. Experimental study of such two-dimensional mixing is the focus of the second part of this work. Results of molecular-dynamics simulations based on proposed theoretical model are reported.

Design and Flight Evaluation of a New Force-Based Flow Angle Probe

NASA Technical Reports Server (NTRS)

Corda, Stephen; Vachon, Michael Jacob

2006-01-01

A novel force-based flow angle probe was designed and flight tested on the NASA F-15B Research Testbed aircraft at NASA Dryden Flight Research Center. The prototype flow angle probe is a small, aerodynamic fin that has no moving parts. Forces on the prototype flow angle probe are measured with strain gages and correlated with the local flow angle. The flow angle probe may provide greater simplicity, greater robustness, and better access to flow measurements in confined areas relative to conventional moving vane-type flow angle probes. Flight test data were obtained at subsonic, transonic, and supersonic Mach numbers to a maximum of Mach 1.70. Flight conditions included takeoff, landing, straight and level flight, flight at higher aircraft angles of attack, and flight at elevated g-loadings. Flight test maneuvers included angle-of-attack and angle-of-sideslip sweeps. The flow angle probe-derived flow angles are compared with those obtained with a conventional moving vane probe. The flight tests validated the feasibility of a force-based flow angle measurement system.

VR Simulation Testbed: Improving Surface Telerobotics for the Deep Space Gateway

NASA Astrophysics Data System (ADS)

Walker, M. E.; Burns, J. O.; Szafir, D. J.

2018-02-01

Design of a virtual reality simulation testbed for prototyping surface telerobotics. The goal is to create a framework with robust physics and kinematics to allow simulated teleoperation and supervised control of lunar rovers and rapid UI prototyping.

Flight Test of GL-1 Glider Half Scale Prototype

NASA Astrophysics Data System (ADS)

Fikri Zulkarnain, Muhammad; Fazlur Rahman, Muhammad; Luthfi Imam Nurhakim, Muhammad; Arifianto, Ony; Mulyanto, Taufiq

2018-04-01

GL-1 is a single-seat mid-performance glider, designed to be Indonesian National Glider. The Glider have been developing since 2014. The development produced a half scale prototype called BL-1, which had accomplished static test in 2016, then followed by first flight test at April 20th 2017, and second flight test at May 21st 2017. The purpose of the flight test was to obtain familiarization of the aircraft, aerodynamics characteristics and flow visualization, with data from flight recorded in FDR. The flight test resulted in two flights with total length of 21 minutes. The data from FDR and flight test documents extracted to analyze the characteristics and behavior of the aircraft during flight test. The aerodynamics characteristic was close to analytical results. The control was good; however, the effectiveness of control surface may need to be further analyzed. The result of the flight test will be used as a reference for further improvements and may need further testing.

Retrieving accurate temporal and spatial information about Taylor slug flows from non-invasive NIR photometry measurements

NASA Astrophysics Data System (ADS)

Helmers, Thorben; Thöming, Jorg; Mießner, Ulrich

2017-11-01

In this article, we introduce a novel approach to retrieve spatial- and time-resolved Taylor slug flow information from a single non-invasive photometric flow sensor. The presented approach uses disperse phase surface properties to retrieve the instantaneous velocity information from a single sensor's time-scaled signal. For this purpose, a photometric sensor system is simulated using a ray-tracing algorithm to calculate spatially resolved near-infrared transmission signals. At the signal position corresponding to the rear droplet cap, a correlation factor of the droplet's geometric properties is retrieved and used to extract the instantaneous droplet velocity from the real sensor's temporal transmission signal. Furthermore, a correlation for the rear cap geometry based on the a priori known total superficial flow velocity is developed, because the cap curvature is velocity sensitive itself. Our model for velocity derivation is validated, and measurements of a first prototype showcase the capability of the device. Long-term measurements visualize systematic fluctuations in droplet lengths, velocities, and frequencies that could otherwise, without the observation on a larger timescale, have been identified as measurement errors and not systematic phenomenas.

Feasibility Test of a Liquid Film Thickness Sensor on a Flexible Printed Circuit Board Using a Three-Electrode Conductance Method

PubMed Central

Lee, Kyu Byung; Kim, Jong Rok; Park, Goon Cherl; Cho, Hyoung Kyu

2016-01-01

Liquid film thickness measurements under temperature-varying conditions in a two-phase flow are of great importance to refining our understanding of two-phase flows. In order to overcome the limitations of the conventional electrical means of measuring the thickness of a liquid film, this study proposes a three-electrode conductance method, with the device fabricated on a flexible printed circuit board (FPCB). The three-electrode conductance method offers the advantage of applicability under conditions with varying temperatures in principle, while the FPCB has the advantage of usability on curved surfaces and in relatively high-temperature conditions in comparison with sensors based on a printed circuit board (PCB). Two types of prototype sensors were fabricated on an FPCB and the feasibility of both was confirmed in a calibration test conducted at different temperatures. With the calibrated sensor, liquid film thickness measurements were conducted via a falling liquid film flow experiment, and the working performance was tested. PMID:28036000

Experimental investigation of a reticulated porous alumina heat exchanger for high temperature gas heat recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee, A; Chandran, RB; Davidson, JH

2015-01-22

The present study presents an experimental study of a prototype counter-flow heat exchanger designed to recover sensible heat from inert and reactive gases flowing through a high temperature solar reactor for splitting CO2. The tube-in-tube heat exchanger is comprised of two concentric alumina tubes, each filled with reticulated porous alumina with a nominal porosity of 80% and pore density of 5 pores per inch (ppi). The RPC provides high heat transfer surface area per unit volume (917 m(-1)) with low pressure drop. Measurements include the permeability, inertial coefficient, overall heat transfer coefficient, effectiveness and pressure drop. For laminar flow andmore » an inlet gas temperature of 1240 K, the overall heat transfer coefficients are 36-41 W m(-2) K-1. The measured performance is in good agreement with a prior CFD model of the heat exchanger. (C) 2014 Elsevier Ltd. All rights reserved.« less

The successful of finite element to invent particle cleaning system by air jet in hard disk drive

NASA Astrophysics Data System (ADS)

Jai-Ngam, Nualpun; Tangchaichit, Kaitfa

2018-02-01

Hard Disk Drive manufacturing has faced very challenging with the increasing demand of high capacity drives for Cloud-based storage. Particle adhesion has also become increasingly important in HDD to gain more reliability of storage capacity. The ability to clean on surfaces is more complicated in removing such particles without damaging the surface. This research is aim to improve the particle cleaning in HSA by using finite element to develop the air flow model then invent the prototype of air cleaning system to remove particle from surface. Surface cleaning by air pressure can be applied as alternative for the removal of solid particulate contaminants that is adhering on a solid surface. These technical and economic challenges have driven the process development from traditional way that chemical solvent cleaning. The focus of this study is to develop alternative way from scrub, ultrasonic, mega sonic on surface cleaning principles to serve as a foundation for the development of new processes to meet current state-of-the-art process requirements and minimize the waste from chemical cleaning for environment safety.

A new approach to fracture modelling in reservoirs using deterministic, genetic and statistical models of fracture growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rawnsley, K.; Swaby, P.

1996-08-01

It is increasingly acknowledged that in order to understand and forecast the behavior of fracture influenced reservoirs we must attempt to reproduce the fracture system geometry and use this as a basis for fluid flow calculation. This article aims to present a recently developed fracture modelling prototype designed specifically for use in hydrocarbon reservoir environments. The prototype {open_quotes}FRAME{close_quotes} (FRActure Modelling Environment) aims to provide a tool which will allow the generation of realistic 3D fracture systems within a reservoir model, constrained to the known geology of the reservoir by both mechanical and statistical considerations, and which can be used asmore » a basis for fluid flow calculation. Two newly developed modelling techniques are used. The first is an interactive tool which allows complex fault surfaces and their associated deformations to be reproduced. The second is a {open_quotes}genetic{close_quotes} model which grows fracture patterns from seeds using conceptual models of fracture development. The user defines the mechanical input and can retrieve all the statistics of the growing fractures to allow comparison to assumed statistical distributions for the reservoir fractures. Input parameters include growth rate, fracture interaction characteristics, orientation maps and density maps. More traditional statistical stochastic fracture models are also incorporated. FRAME is designed to allow the geologist to input hard or soft data including seismically defined surfaces, well fractures, outcrop models, analogue or numerical mechanical models or geological {open_quotes}feeling{close_quotes}. The geologist is not restricted to {open_quotes}a priori{close_quotes} models of fracture patterns that may not correspond to the data.« less

Active Combustion Control for Aircraft Gas-Turbine Engines-Experimental Results for an Advanced, Low-Emissions Combustor Prototype

NASA Technical Reports Server (NTRS)

DeLaat, John C.; Kopasakis, George; Saus, Joseph R.; Chang, Clarence T.; Wey, Changlie

2012-01-01

Lean combustion concepts for aircraft engine combustors are prone to combustion instabilities. Mitigation of instabilities is an enabling technology for these low-emissions combustors. NASA Glenn Research Center s prior activity has demonstrated active control to suppress a high-frequency combustion instability in a combustor rig designed to emulate an actual aircraft engine instability experience with a conventional, rich-front-end combustor. The current effort is developing further understanding of the problem specifically as applied to future lean-burning, very low-emissions combustors. A prototype advanced, low-emissions aircraft engine combustor with a combustion instability has been identified and previous work has characterized the dynamic behavior of that combustor prototype. The combustor exhibits thermoacoustic instabilities that are related to increasing fuel flow and that potentially prevent full-power operation. A simplified, non-linear oscillator model and a more physics-based sectored 1-D dynamic model have been developed to capture the combustor prototype s instability behavior. Utilizing these models, the NASA Adaptive Sliding Phasor Average Control (ASPAC) instability control method has been updated for the low-emissions combustor prototype. Active combustion instability suppression using the ASPAC control method has been demonstrated experimentally with this combustor prototype in a NASA combustion test cell operating at engine pressures, temperatures, and flows. A high-frequency fuel valve was utilized to perturb the combustor fuel flow. Successful instability suppression was shown using a dynamic pressure sensor in the combustor for controller feedback. Instability control was also shown with a pressure feedback sensor in the lower temperature region upstream of the combustor. It was also demonstrated that the controller can prevent the instability from occurring while combustor operation was transitioning from a stable, low-power condition to a normally unstable high-power condition, thus enabling the high-power condition.

Characterization of mixing in an electroosmotically stirred continuous micro mixer

NASA Astrophysics Data System (ADS)

Beskok, Ali

2005-11-01

We present theoretical and numerical studies of mixing in a straight micro channel with zeta potential patterned surfaces. A steady pressure driven flow is maintained in the channel in addition to a time dependent electroosmotic flow, generated by a stream-wise AC electric field. The zeta potential patterns are placed critically in the channel to achieve spatially asymmetric time-dependent flow patterns that lead to chaotic stirring. Fixing the geometry, we performed parametric studies of passive particle motion that led to generation of Poincare sections and characterization of chaotic strength by finite time Lyapunov exponents. The parametric studies were performed as a function of the Womersley number (normalized AC frequency) and the ratio of Poiseuille flow and electroosmotic velocities. After determining the non-dimensional parameters that led to high chaotic strength, we performed spectral element simulations of species transport and mixing at high Peclet numbers, and characterized mixing efficiency using the Mixing Index inverse. Mixing lengths proportional to the natural logarithm of the Peclet number are reported. Using the optimum non-dimensional parameters and the typical magnitudes involved in electroosmotic flows, we were able to determine the physical dimensions and operation conditions for a prototype micro-mixer.

Predictive model for local scour downstream of hydrokinetic turbines in erodible channels

NASA Astrophysics Data System (ADS)

Musa, Mirko; Heisel, Michael; Guala, Michele

2018-02-01

A modeling framework is derived to predict the scour induced by marine hydrokinetic turbines installed on fluvial or tidal erodible bed surfaces. Following recent advances in bridge scour formulation, the phenomenological theory of turbulence is applied to describe the flow structures that dictate the equilibrium scour depth condition at the turbine base. Using scaling arguments, we link the turbine operating conditions to the flow structures and scour depth through the drag force exerted by the device on the flow. The resulting theoretical model predicts scour depth using dimensionless parameters and considers two potential scenarios depending on the proximity of the turbine rotor to the erodible bed. The model is validated at the laboratory scale with experimental data comprising the two sediment mobility regimes (clear water and live bed), different turbine configurations, hydraulic settings, bed material compositions, and migrating bedform types. The present work provides future developers of flow energy conversion technologies with a physics-based predictive formula for local scour depth beneficial to feasibility studies and anchoring system design. A potential prototype-scale deployment in a large sandy river is also considered with our model to quantify how the expected scour depth varies as a function of the flow discharge and rotor diameter.

Preliminary design of a prototype particulate stack sampler. [For stack gas temperature under 300/sup 0/C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elder, J.C.; Littlefield, L.G.; Tillery, M.I.

1978-06-01

A preliminary design of a prototype particulate stack sampler (PPSS) has been prepared, and development of several components is under way. The objective of this Environmental Protection Agency (EPA)-sponsored program is to develop and demonstrate a prototype sampler with capabilities similar to EPA Method 5 apparatus but without some of the more troublesome aspects. Features of the new design include higher sampling flow; display (on demand) of all variables and periodic calculation of percent isokinetic, sample volume, and stack velocity; automatic control of probe and filter heaters; stainless steel surfaces in contact with the sample stream; single-point particle size separationmore » in the probe nozzle; null-probe capability in the nozzle; and lower weight in the components of the sampling train. Design considerations will limit use of the PPSS to stack gas temperatures under approximately 300/sup 0/C, which will exclude sampling some high-temperature stacks such as incinerators. Although need for filter weighing has not been eliminated in the new design, introduction of a variable-slit virtual impactor nozzle may eliminate the need for mass analysis of particles washed from the probe. Component development has shown some promise for continuous humidity measurement by an in-line wet-bulb, dry-bulb psychrometer.« less

Performance characteristics of constant-flow phase dilution oxygen mask designs for general aviation.

DOT National Transportation Integrated Search

1967-05-01

The report describes evaluation of two prototype phase dilution rebreathing masks as compared to an open port rebreathing mask design. Human subjects wearing the prototype masks and engaged in three minute periods of rest and exercise were exposed to...

A Human Subject Evaluation of Airport Surface Situational Awareness Using Prototypical Flight Deck Electronic Taxi Chart Displays

DOT National Transportation Integrated Search

1995-11-01

A study was conducted to test the effect on airport surface situational awareness of GPS derived position information : depicted on a prototypical electronic taxi chart display. The effect of position error and position uncertainty : symbology were a...

Conceptual design of a pre-loaded liquid lithium divertor target for NSTX-U

DOE PAGES

Rindt, P.; Lopes Cardozo, N. J.; van Dommelen, J. A. W.; ...

2016-09-03

In this study, a conceptual design for a pre-filled liquid lithium divertor target for the National Spherical Torus Experiment Upgrade (NSTX-U) is presented. The design is aimed at facilitating experiments with high lithium flux from the plasma facing components (PFCs) in NSTX-U and investigating the potential of capillary based liquid lithium components. In the design, lithium is supplied from a reservoir in the PFC to the plasma facing surface via capillary action in a wicking structure. This working principle is also demonstrated experimentally. Next, a titanium zirconium molybdenum (TZM) prototype design is presented, required to withstand a steady state heatmore » flux peaking at 10 MW m –2 for 5 s and edge localized modes depositing (130 kJ in 2 ms at 10 Hz). The main challenge is to sufficiently reduce the thermal stresses. This is achieved by dividing the surface into brushes and filling the slots in between with liquid lithium. The principle of using this liquid “interlayer” allows for thermal expansion and simultaneously heat conduction, and could be used to significantly reduce the demands to solids in future PFCs. Lithium flow to the surface is analyzed using a novel analytical model, ideally suited for design purposes. Thermal stresses in the PFC are analyzed using the finite element method. As a result, the requirements are met, and thus a prototype will be manufactured for physical testing.« less

Conceptual design of a pre-loaded liquid lithium divertor target for NSTX-U

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rindt, P.; Lopes Cardozo, N. J.; van Dommelen, J. A. W.

In this study, a conceptual design for a pre-filled liquid lithium divertor target for the National Spherical Torus Experiment Upgrade (NSTX-U) is presented. The design is aimed at facilitating experiments with high lithium flux from the plasma facing components (PFCs) in NSTX-U and investigating the potential of capillary based liquid lithium components. In the design, lithium is supplied from a reservoir in the PFC to the plasma facing surface via capillary action in a wicking structure. This working principle is also demonstrated experimentally. Next, a titanium zirconium molybdenum (TZM) prototype design is presented, required to withstand a steady state heatmore » flux peaking at 10 MW m –2 for 5 s and edge localized modes depositing (130 kJ in 2 ms at 10 Hz). The main challenge is to sufficiently reduce the thermal stresses. This is achieved by dividing the surface into brushes and filling the slots in between with liquid lithium. The principle of using this liquid “interlayer” allows for thermal expansion and simultaneously heat conduction, and could be used to significantly reduce the demands to solids in future PFCs. Lithium flow to the surface is analyzed using a novel analytical model, ideally suited for design purposes. Thermal stresses in the PFC are analyzed using the finite element method. As a result, the requirements are met, and thus a prototype will be manufactured for physical testing.« less

Development of prototype decision support systems for real-time freeway traffic routing. Volume I.

DOT National Transportation Integrated Search

1998-01-01

For a traffic management system (TMS) to improve traffic flow, TMS operators must develop effective routing strategies based on the data collected by the system. The purpose of this research was to build prototype decision support systems (DSS) for t...

Centrifuge in space fluid flow visualization experiment

NASA Technical Reports Server (NTRS)

Arnold, William A.; Wilcox, William R.; Regel, Liya L.; Dunbar, Bonnie J.

1993-01-01

A prototype flow visualization system is constructed to examine buoyancy driven flows during centrifugation in space. An axial density gradient is formed by imposing a thermal gradient between the two ends of the test cell. Numerical computations for this geometry showed that the Prandtl number plays a limited part in determining the flow.

New concepts for Reynolds stress transport equation modeling of inhomogeneous flows

NASA Technical Reports Server (NTRS)

Perot, J. Blair; Moin, Parviz

1993-01-01

The ability to model turbulence near solid walls and other types of boundaries is important in predicting complex engineering flows. Most turbulence modeling has concentrated either on flows which are nearly homogeneous or isotropic, or on turbulent boundary layers. Boundary layer models usually rely very heavily on the presence of mean shear and the production of turbulence due to that mean shear. Most other turbulence models are based on the assumption of quasi-homogeneity. However, there are many situations of engineering interest which do not involve large shear rates and which are not quasi-homogeneous or isotropic. Shear-free turbulent boundary layers are the prototypical example of such flows, with practical situations being separation and reattachment, bluff body flow, high free-stream turbulence, and free surface flows. Although these situations are not as common as the variants of the flat plate turbulent boundary layer, they tend to be critical factors in complex engineering situations. The models developed are intended to extend classical quasi-homogeneous models into regions of large inhomogeneity. These models do not rely on the presence of mean shear or production, but are still applicable when those additional effects are included. Although the focus is on shear-free boundary layers as tests for these models, results for standard shearing boundary layers are also shown.

Velocity and pressure measurements in guide vane clearance gap of a low specific speed Francis turbine

NASA Astrophysics Data System (ADS)

Thapa, B. S.; Dahlhaug, O. G.; Thapa, B.

2016-11-01

In Francis turbine, a small clearance gap between the guide vanes and the cover plates is usually required to pivot guide vanes as a part of governing system. Deflection of cover plates and erosion of mating surfaces causes this gap to increase from its design value. The clearance gap induces the secondary flow in the distributor system. This effects the main flow at the runner inlet, which causes losses in efficiency and instability. A guide vane cascade of a low specific speed Francis turbine has been developed for experimental investigations. The test setup is able to produce similar velocity distributions at the runner inlet as that of a reference prototype turbine. The setup is designed for particle image velocimetry (PIV) measurements from the position of stay vane outlet to the position of runner inlet. In this study, velocity and pressure measurements are conducted with 2 mm clearance gap on one side of guide vane. Leakage flow is observed and measured together with pressure measurements. It is concluded that the leakage flow behaves as a jet and mixes with the main flow in cross-wise direction and forms a vortex filament. This causes non-uniform inlet flow conditions at runner blades.

Design of a prototype flow microreactor for synthetic biology in vitro.

PubMed

Boehm, Christian R; Freemont, Paul S; Ces, Oscar

2013-09-07

As a reference platform for in vitro synthetic biology, we have developed a prototype flow microreactor for enzymatic biosynthesis. We report the design, implementation, and computer-aided optimisation of a three-step model pathway within a microfluidic reactor. A packed bed format was shown to be optimal for enzyme compartmentalisation after experimental evaluation of several approaches. The specific substrate conversion efficiency could significantly be improved by an optimised parameter set obtained by computational modelling. Our microreactor design provides a platform to explore new in vitro synthetic biology solutions for industrial biosynthesis.

Cash Flow Statement Spreadsheet Modeling Case Using a Prototype System Development Process

ERIC Educational Resources Information Center

Davis, Jefferson T.

2015-01-01

U.S. GAAP and IFRS standards both require a cash flow statement that presents operating, investing and financing net cash flows (FASB, FAS 95; 1987; IASB, IAS 7, 1992). Although students are exposed to the cash flow statement in beginning accounting courses and then study the cash flow statement in more depth in intermediate accounting classes,…

Molecular vibrational energy flow

NASA Astrophysics Data System (ADS)

Gruebele, M.; Bigwood, R.

This article reviews some recent work in molecular vibrational energy flow (IVR), with emphasis on our own computational and experimental studies. We consider the problem in various representations, and use these to develop a family of simple models which combine specific molecular properties (e.g. size, vibrational frequencies) with statistical properties of the potential energy surface and wavefunctions. This marriage of molecular detail and statistical simplification captures trends of IVR mechanisms and survival probabilities beyond the abilities of purely statistical models or the computational limitations of full ab initio approaches. Of particular interest is IVR in the intermediate time regime, where heavy-atom skeletal modes take over the IVR process from hydrogenic motions even upon X H bond excitation. Experiments and calculations on prototype heavy-atom systems show that intermediate time IVR differs in many aspects from the early stages of hydrogenic mode IVR. As a result, IVR can be coherently frozen, with potential applications to selective chemistry.

Experimental investigations of helium cryotrapping by argon frost

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mack, A.; Perinic, D.; Murdoch, D.

1992-03-01

At the Karlsruhe Nuclear Research Centre (KfK) cryopumping techniques are being investigated by which the gaseous exhausts from the NET/ITER reactor can be pumped out during the burn-and dwell-times. Cryosorption and cryotrapping are techniques which are suitable for this task. It is the target of the investigations to test the techniques under NET/ITER conditions and to determine optimum design data for a prototype. They involve measurement of the pumping speed as a function of the gas composition, gas flow and loading condition of the pump surfaces. The following parameters are subjected to variations: Ar/He ratio, specific helium volume flow rate,more » cryosurface temperature, process gas composition, impurities in argon trapping gas, three-stage operation and two-stage operation. This paper is a description of the experiments on argon trapping techniques started in 1990. Eleven tests as well as the results derived from them are described.« less

AREVA Team Develops Sump Strainer Blockage Solution for PWRs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phan, Ray

2006-07-01

The purpose of this paper is to discuss the methodology, testing challenges, and results of testing that a team of experts from Areva NP, Alden Research Laboratory, Inc (ALDEN), and Performance Contracting Inc. (PCI) has developed. The team is currently implementing a comprehensive solution to the issue of Emergency Core Cooling System (ECCS) sump strainer blockage facing Pressurized Water Reactor (PWR) Nuclear Plants. The team has successfully demonstrated two key results from the testing of passive Sure-FlowTM strainers, which were designed to distribute the required flow over a large surface area resulting in extremely low approach velocities. First, the actualmore » head loss (pressure drop) as tested, across the prototype strainers, was much lower than the calculated head loss using the Nuclear Regulatory Commission (NRC) approved NUREG/CR-6224 head loss correlation. Second, the penetration fractions were much lower than those seen in the NRC sponsored debris penetration tests. (author)« less

DEVELOPMENT AND LABORATORY CHARACTERIZATION OF A PROTOTYPE COARSE PARTICLE CONCENTRATOR FOR INHALATION TOXICOLOGICAL STUDIES. (R825270)

EPA Science Inventory

This paper presents the development and laboratory characterization of a prototype slit nozzle virtual impactor that can be used to concentrate coarse particles. A variety of physical design and flow parameters were evaluated including different acceleration and collection sli...

Using 3D Printing for Rapid Prototyping of Characterization Tools for Investigating Powder Blend Behavior.

PubMed

Hirschberg, Cosima; Boetker, Johan P; Rantanen, Jukka; Pein-Hackelbusch, Miriam

2018-02-01

There is an increasing need to provide more detailed insight into the behavior of particulate systems. The current powder characterization tools are developed empirically and in many cases, modification of existing equipment is difficult. More flexible tools are needed to provide understanding of complex powder behavior, such as mixing process and segregation phenomenon. An approach based on the fast prototyping of new powder handling geometries and interfacing solutions for process analytical tools is reported. This study utilized 3D printing for rapid prototyping of customized geometries; overall goal was to assess mixing process of powder blends at small-scale with a combination of spectroscopic and mechanical monitoring. As part of the segregation evaluation studies, the flowability of three different paracetamol/filler-blends at different ratios was investigated, inter alia to define the percolation thresholds. Blends with a paracetamol wt% above the percolation threshold were subsequently investigated in relation to their segregation behavior. Rapid prototyping using 3D printing allowed designing two funnels with tailored flow behavior (funnel flow) of model formulations, which could be monitored with an in-line near-infrared (NIR) spectrometer. Calculating the root mean square (RMS) of the scores of the two first principal components of the NIR spectra visualized spectral variation as a function of process time. In a same setup, mechanical properties (basic flow energy) of the powder blend were monitored during blending. Rapid prototyping allowed for fast modification of powder testing geometries and easy interfacing with process analytical tools, opening new possibilities for more detailed powder characterization.

Experimental analysis of flow structure in contra-rotating axial flow pump designed with different rotational speed concept

NASA Astrophysics Data System (ADS)

Cao, Linlin; Watanabe, Satoshi; Imanishi, Toshiki; Yoshimura, Hiroaki; Furukawa, Akinori

2013-08-01

As a high specific speed pump, the contra-rotating axial flow pump distinguishes itself in a rear rotor rotating in the opposite direction of the front rotor, which remarkably contributes to the energy conversion, the reduction of the pump size, better hydraulic and cavitation performances. However, with two rotors rotating reversely, the significant interaction between blade rows was observed in our prototype contra-rotating rotors, which highly affected the pump performance compared with the conventional axial flow pumps. Consequently, a new type of rear rotor was designed by the rotational speed optimization methodology with some additional considerations, aiming at better cavitation performance, the reduction of blade rows interaction and the secondary flow suppression. The new rear rotor showed a satisfactory performance at the design flow rate but an unfavorable positive slope of the head — flow rate curve in the partial flow rate range less than 40% of the design flow rate, which should be avoided for the reliability of pump-pipe systems. In the present research, to understand the internal flow field of new rear rotor and its relation to the performances at the partial flow rates, the velocity distributions at the inlets and outlets of the rotors are firstly investigated. Then, the boundary layer flows on rotor surfaces, which clearly reflect the secondary flow inside the rotors, are analyzed through the limiting streamline observations using the multi-color oil-film method. Finally, the unsteady numerical simulations are carried out to understand the complicated internal flow structures in the rotors.

Evaluation of a prototype flow cytometry test for serodiagnosis of canine visceral leishmaniasis.

PubMed

Ker, Henrique Gama; Coura-Vital, Wendel; Aguiar-Soares, Rodrigo Dian de Oliveira; Roatt, Bruno Mendes; das Dores Moreira, Nádia; Carneiro, Cláudia Martins; Machado, Evandro Marques de Menezes; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis; Giunchetti, Rodolfo Cordeiro; Araújo, Márcio Sobreira Silva; Coelho, Eduardo Antonio Ferraz; da Silveira-Lemos, Denise; Reis, Alexandre Barbosa

2013-12-01

Diagnosing canine visceral leishmaniasis (CVL) is a critical challenge since conventional immunoserological tests still present some deficiencies. The current study evaluated a prototype flow cytometry serology test, using antigens and fluorescent antibodies that had been stored for 1 year at 4°C, on a broad range of serum samples. Noninfected control dogs and Leishmania infantum-infected dogs were tested, and the prototype test showed excellent performance in differentiating these groups with high sensitivity, specificity, positive and negative predictive values, and accuracy (100% in all analyses). When the CVL group was evaluated according to the dogs' clinical status, the prototype test showed outstanding accuracy in all groups with positive serology (asymptomatic II, oligosymptomatic, and symptomatic). However, in dogs which had positive results by PCR-restriction fragment length polymorphism (RFLP) but negative results by conventional serology (asymptomatic I), serological reactivity was not observed. Additionally, sera from 40 dogs immunized with different vaccines (Leishmune, Leish-Tec, or LBSap) did not present serological reactivity in the prototype test. Eighty-eight dogs infected with other pathogens (Trypanosoma cruzi, Leishmania braziliensis, Ehrlichia canis, and Babesia canis) were used to determine cross-reactivity and specificity, and the prototype test performed well, particularly in dogs infected with B. canis and E. canis (100% and 93.3% specificities, respectively). In conclusion, our data reinforce the potential of the prototype test for use as a commercial kit and highlight its outstanding performance even after storage for 1 year at 4°C. Moreover, the prototype test efficiently provided accurate CVL serodiagnosis with an absence of false-positive results in vaccinated dogs and minor cross-reactivity against other canine pathogens.

Aeroelastic characteristics of a rapid prototype multi-material wind tunnel model of a mechanically deployable aerodynamic decelerator

NASA Astrophysics Data System (ADS)

Raskin, Boris

Scaled wind tunnel models are necessary for the development of aircraft and spacecraft to simulate aerodynamic behavior. This allows for testing multiple iterations of a design before more expensive full-scale aircraft and spacecraft are built. However, the cost of building wind tunnel models can still be high because they normally require costly subtractive manufacturing processes, such as machining, which can be time consuming and laborious due to the complex surfaces of aerodynamic models. Rapid prototyping, commonly known as 3D printing, can be utilized to save on wind tunnel model manufacturing costs. A rapid prototype multi-material wind tunnel model was manufactured for this thesis to investigate the possibility of using PolyJet 3D printing to create a model that exhibits aeroelastic behavior. The model is of NASA's Adaptable Deployable entry and Placement (ADEPT) aerodynamic decelerator, used to decelerate a spacecraft during reentry into a planet's atmosphere. It is a 60° cone with a spherically blunted nose that consists of a 12 flexible panels supported by a rigid structure of nose, ribs, and rim. The novel rapid prototype multi-material model was instrumented and tested in two flow conditions. Quantitative comparisons were made of the average forces and dynamic forces on the model, demonstrating that the model matched expected behavior for average drag, but not Strouhal number, indicating that there was no aeroelastic behavior in this particular case. It was also noted that the dynamic properties (e.g., resonant frequency) associated with the mounting scheme are very important and may dominate the measured dynamic response.

Autonomous sensor particle for parameter tracking in large vessels

NASA Astrophysics Data System (ADS)

Thiele, Sebastian; Da Silva, Marco Jose; Hampel, Uwe

2010-08-01

A self-powered and neutrally buoyant sensor particle has been developed for the long-term measurement of spatially distributed process parameters in the chemically harsh environments of large vessels. One intended application is the measurement of flow parameters in stirred fermentation biogas reactors. The prototype sensor particle is a robust and neutrally buoyant capsule, which allows free movement with the flow. It contains measurement devices that log the temperature, absolute pressure (immersion depth) and 3D-acceleration data. A careful calibration including an uncertainty analysis has been performed. Furthermore, autonomous operation of the developed prototype was successfully proven in a flow experiment in a stirred reactor model. It showed that the sensor particle is feasible for future application in fermentation reactors and other industrial processes.

Short-time-scale left ventricular systolic dynamics. Evidence for a common mechanism in both left ventricular chamber and heart muscle mechanics.

PubMed

Campbell, K B; Shroff, S G; Kirkpatrick, R D

1991-06-01

Based on the premise that short-time-scale, small-amplitude pressure/volume/outflow behavior of the left ventricular chamber was dominated by dynamic processes originating in cardiac myofilaments, a prototype model was built to predict pressure responses to volume perturbations. In the model, chamber pressure was taken to be the product of the number of generators in a pressure-bearing state and their average volumetric distortion, as in the muscle theory of A.F. Huxley, in which force was equal to the number of attached crossbridges and their average lineal distortion. Further, as in the muscle theory, pressure generators were assumed to cycle between two states, the pressure-bearing state and the non-pressure-bearing state. Experiments were performed in the isolated ferret heart, where variable volume decrements (0.01-0.12 ml) were removed at two commanded flow rates (flow clamps, -7 and -14 ml/sec). Pressure responses to volume removals were analyzed. Although the prototype model accounted for most features of the pressure responses, subtle but systematic discrepancies were observed. The presence or absence of flow and the magnitude of flow affected estimates of model parameters. However, estimates of parameters did not differ when the model was fitted to flow clamps with similar magnitudes of flows but different volume changes. Thus, prototype model inadequacies were attributed to misrepresentations of flow-related effects but not of volume-related effects. Based on these discrepancies, an improved model was built that added to the simple two-state cycling scheme, a pathway to a third state. This path was followed only in response to volume change. The improved model eliminated the deficiencies of the prototype model and was adequate in accounting for all observations. Since the template for the improved model was taken from the cycling crossbridge theory of muscle contraction, it was concluded that, in spite of the complexities of geometry, architecture, and regional heterogeneity of function and structure, crossbridge mechanisms dominated the short-time-scale dynamics of left ventricular chamber behavior.

Real-time data flow and product generating for GNSS

NASA Technical Reports Server (NTRS)

Muellerschoen, Ronald J.; Caissy, Mark

2004-01-01

The last IGS workshop with the theme 'Towards Real-Time' resulted in the design of a prototype for real-time data and sharing within the IGS. A prototype real-time network is being established that will serve as a test bed for real-time activities within the IGS. We review the developments of the prototype and discuss some of the existing methods and related products of real-time GNSS systems. Recommendations are made concerning real-time data distribution and product generation.

Prototype of an in vitro model of the microcirculation.

PubMed

Shevkoplyas, Sergey S; Gifford, Sean C; Yoshida, Tatsuro; Bitensky, Mark W

2003-03-01

We have used microfabrication technology to construct a network of microchannels, patterned after the dimensions and architecture of the mammalian microcirculation. The network is cast in transparent silicone elastomer and the channels are coated with silanated mPEG to provide lubrication. Flow of red and white blood cells through the network is readily visualized by the use of high-speed digital image acquisition. The acquired sequences of high-quality images are used to calculate hematocrits and rates of red cell movement in the microchannels. Our prototype system has significant advantages over scaled-up room-size experimental systems in that it permits experimentation with actual human blood cells. Experiments can be carried out under well-controlled conditions in a network of microchannels with precisely known dimensions using cell suspensions of defined composition. Moreover, there is no need to counteract or anticipate the host's adaptive responses that may confound live animal experiments. Notwithstanding its limitations, the current prototype demonstrates certain features characteristic of the microcirculation, such as parachute and bullet shapes of red cells deformed in capillary channels, rouleaux formation, plasma skimming, and the utilization of collateral flow pathways due to flow obstruction caused by a white cell blocking a microchannel. We present this device as a prototype scale-to-scale model of the mammalian microcirculation. Limitations of the system as well as a variety of possible applications are described.

Characterization of thermal-hydraulic and ignition phenomena in prototypic, full-length boiling water reactor spent fuel pool assemblies after a complete loss-of-coolant accident.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindgren, Eric Richard; Durbin, Samuel G

2007-04-01

The objective of this project was to provide basic thermal-hydraulic data associated with a SFP complete loss-of-coolant accident. The accident conditions of interest for the SFP were simulated in a full-scale prototypic fashion (electrically-heated, prototypic assemblies in a prototypic SFP rack) so that the experimental results closely represent actual fuel assembly responses. A major impetus for this work was to facilitate code validation (primarily MELCOR) and reduce questions associated with interpretation of the experimental results. It was necessary to simulate a cluster of assemblies to represent a higher decay (younger) assembly surrounded by older, lower-power assemblies. Specifically, this program providedmore » data and analysis confirming: (1) MELCOR modeling of inter-assembly radiant heat transfer, (2) flow resistance modeling and the natural convective flow induced in a fuel assembly as it heats up in air, (3) the potential for and nature of thermal transient (i.e., Zircaloy fire) propagation, and (4) mitigation strategies concerning fuel assembly management.« less

Air injection test on a Kaplan turbine: prototype - model comparison

NASA Astrophysics Data System (ADS)

Angulo, M.; Rivetti, A.; Díaz, L.; Liscia, S.

2016-11-01

Air injection is a very well-known resource to reduce pressure pulsation magnitude in turbines, especially on Francis type. In the case of large Kaplan designs, even when not so usual, it could be a solution to mitigate vibrations arising when tip vortex cavitation phenomenon becomes erosive and induces structural vibrations. In order to study this alternative, aeration tests were performed on a Kaplan turbine at model and prototype scales. The research was focused on efficiency of different air flow rates injected in reducing vibrations, especially at the draft tube and the discharge ring and also in the efficiency drop magnitude. It was found that results on both scales presents the same trend in particular for vibration levels at the discharge ring. The efficiency drop was overestimated on model tests while on prototype were less than 0.2 % for all power output. On prototype, air has a beneficial effect in reducing pressure fluctuations up to 0.2 ‰ of air flow rate. On model high speed image computing helped to quantify the volume of tip vortex cavitation that is strongly correlated with the vibration level. The hydrophone measurements did not capture the cavitation intensity when air is injected, however on prototype, it was detected by a sonometer installed at the draft tube access gallery.

Laser Doppler imaging of cutaneous blood flow through transparent face masks: a necessary preamble to computer-controlled rapid prototyping fabrication with submillimeter precision.

PubMed

Allely, Rebekah R; Van-Buendia, Lan B; Jeng, James C; White, Patricia; Wu, Jingshu; Niszczak, Jonathan; Jordan, Marion H

2008-01-01

A paradigm shift in management of postburn facial scarring is lurking "just beneath the waves" with the widespread availability of two recent technologies: precise three-dimensional scanning/digitizing of complex surfaces and computer-controlled rapid prototyping three-dimensional "printers". Laser Doppler imaging may be the sensible method to track the scar hyperemia that should form the basis of assessing progress and directing incremental changes in the digitized topographical face mask "prescription". The purpose of this study was to establish feasibility of detecting perfusion through transparent face masks using the Laser Doppler Imaging scanner. Laser Doppler images of perfusion were obtained at multiple facial regions on five uninjured staff members. Images were obtained without a mask, followed by images with a loose fitting mask with and without a silicone liner, and then with a tight fitting mask with and without a silicone liner. Right and left oblique images, in addition to the frontal images, were used to overcome unobtainable measurements at the extremes of face mask curvature. General linear model, mixed model, and t tests were used for data analysis. Three hundred seventy-five measurements were used for analysis, with a mean perfusion unit of 299 and pixel validity of 97%. The effect of face mask pressure with and without the silicone liner was readily quantified with significant changes in mean cutaneous blood flow (P < .5). High valid pixel rate laser Doppler imager flow data can be obtained through transparent face masks. Perfusion decreases with the application of pressure and with silicone. Every participant measured differently in perfusion units; however, consistent perfusion patterns in the face were observed.

Applications of TRMM-based Multi-Satellite Precipitation Estimation for Global Runoff Simulation: Prototyping a Global Flood Monitoring System

NASA Technical Reports Server (NTRS)

Hong, Yang; Adler, Robert F.; Huffman, George J.; Pierce, Harold

2008-01-01

Advances in flood monitoring/forecasting have been constrained by the difficulty in estimating rainfall continuously over space (catchment-, national-, continental-, or even global-scale areas) and flood-relevant time scale. With the recent availability of satellite rainfall estimates at fine time and space resolution, this paper describes a prototype research framework for global flood monitoring by combining real-time satellite observations with a database of global terrestrial characteristics through a hydrologically relevant modeling scheme. Four major components included in the framework are (1) real-time precipitation input from NASA TRMM-based Multi-satellite Precipitation Analysis (TMPA); (2) a central geospatial database to preprocess the land surface characteristics: water divides, slopes, soils, land use, flow directions, flow accumulation, drainage network etc.; (3) a modified distributed hydrological model to convert rainfall to runoff and route the flow through the stream network in order to predict the timing and severity of the flood wave, and (4) an open-access web interface to quickly disseminate flood alerts for potential decision-making. Retrospective simulations for 1998-2006 demonstrate that the Global Flood Monitor (GFM) system performs consistently at both station and catchment levels. The GFM website (experimental version) has been running at near real-time in an effort to offer a cost-effective solution to the ultimate challenge of building natural disaster early warning systems for the data-sparse regions of the world. The interactive GFM website shows close-up maps of the flood risks overlaid on topography/population or integrated with the Google-Earth visualization tool. One additional capability, which extends forecast lead-time by assimilating QPF into the GFM, also will be implemented in the future.

Note: Ultrasonic gas flowmeter based on optimized time-of-flight algorithms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, X. F.; Tang, Z. A.

2011-04-15

A new digital signal processor based single path ultrasonic gas flowmeter is designed, constructed, and experimentally tested. To achieve high accuracy measurements, an optimized ultrasound driven method of incorporation of the amplitude modulation and the phase modulation of the transmit-receive technique is used to stimulate the transmitter. Based on the regularities among the received envelope zero-crossings, different received signal's signal-to-noise ratio situations are discriminated and optional time-of-flight algorithms are applied to take flow rate calculations. Experimental results from the dry calibration indicate that the designed flowmeter prototype can meet the zero-flow verification test requirements of the American Gas Association Reportmore » No. 9. Furthermore, the results derived from the flow calibration prove that the proposed flowmeter prototype can measure flow rate accurately in the practical experiments, and the nominal accuracies after FWME adjustment are lower than 0.8% throughout the calibration range.« less

The STREON Recirculation Chamber: An Advanced Tool to Quantify Stream Ecosystem Metabolism in the Benthic Zone

NASA Astrophysics Data System (ADS)

Brock, J. T.; Utz, R.; McLaughlin, B.

2013-12-01

The STReam Experimental Observatory Network is a large-scale experimental effort that will investigate the effects of eutrophication and loss of large consumers in stream ecosystems. STREON represents the first experimental effort undertaken and supported by the National Ecological Observatory Network (NEON).Two treatments will be applied at 10 NEON sites and maintained for 10 years in the STREON program: the addition of nitrate and phosphate to enrich concentrations by five times ambient levels and electrical fields that exclude top consumers (i.e., fish or invertebrates) of the food web from the surface of buried sediment baskets. Following a 3-5 week period, the sediment baskets will be extracted and incubated in closed, recirculating metabolic chambers to measure rates of respiration, photosynthesis, and nutrient uptake. All STREON-generated data will be open access and available on the NEON web portal. The recirculation chamber represents a critical infrastructural component of STREON. Although researchers have applied such chambers for metabolic and nutrient uptake measurements in the past, the scope of STREON demands a novel design that addresses multiple processes often neglected by earlier models. The STREON recirculation chamber must be capable of: 1) incorporating hyporheic exchange into the flow field to ensure measurements of respiration include the activity of subsurface biota, 2) operating consistently with heterogeneous sediments from sand to cobble, 3) minimizing heat exchange from the motor and external environment, 4) delivering a reproducible uniform flow field over the surface of the sediment basket, and 5) efficient assembly/disassembly with minimal use of tools. The chamber also required a means of accommodating an optical dissolved oxygen probe and a means to inject/extract water. A prototype STREON chamber has been designed and thoroughly tested. The flow field within the chamber has been mapped using particle imaging velocimetry (PIV) under various velocity settings. The extent of exchange with the sediment was assessed by means of a saline tracer injection and adjustment using flow-regulating components was explored. Performance under a broad range of temperatures (1 to 30 °C) was assessed. Finally, a novel heat-exchange mechanism meant to minimize warming during operations was evaluated. All prototype assessments demonstrate the applicability of the STREON chamber under a broad range of conditions. Though the STREON recirculation chamber has been designed to satisfy the specific needs of the STREON program, the open-access nature of the NEON network should facilitate scope expansion in the coming decades. The STREON recirculation chamber design and all prototype testing data will be accessible to facilitate chamber use elsewhere. The large number of chamber assemblies required for STREON operations should facilitate the acquisition of units by researchers working outside of the NEON network. Furthermore, the current scope of STREON includes the use of the chambers only once annually, thus a valuable tool for stream ecosystem measurements will be readily available at STREON sites for potential use by researchers interested in such measurements.

Performance of prototype high-flow inhalable dust sampler in a livestock production facility.

PubMed

Anthony, T Renée; Cai, Changjie; Mehaffy, John; Sleeth, Darrah; Volckens, John

2017-05-01

A high-flow inhalable sampler, designed for operational flow rates up to 10 L/min using computer simulations and examined in wind tunnel experiments, was evaluated in the field. This prototype sampler was deployed in collocation with an IOM (the benchmark standard sampler) in a swine farrowing building to examine the sampling performance for assessing concentrations of inhalable particulate mass and endotoxin. Paired samplers were deployed for 24 hr on 19 days over a 3-month period. On each sampling day, the paired samplers were deployed at three fixed locations and data were analyzed to identify agreement and to examine systematic biases between concentrations measured by these samplers. Thirty-six paired gravimetric samples were analyzed; insignificant, unsubstantial differences between concentrations were identified between the two samplers (p = 0.16; mean difference 0.03 mg/m 3 ). Forty-four paired samples were available for endotoxin analysis, and a significant (p = 0.001) difference in endotoxin concentration was identified: the prototype sampler, on average, had 120 EU/m 3 more endotoxin than did the IOM samples. Since the same gravimetric samples were analyzed for endotoxin content, the endotoxin difference is likely attributable to differences in endotoxin extraction. The prototype's disposable thin-film polycarbonate capsule was included with the filter in the 1-hr extraction procedure while the internal plastic cassette of the IOM required a rinse procedure that is susceptible to dust losses. Endotoxin concentrations measured with standard plastic IOM inserts that follow this rinsing procedure may underestimate the true endotoxin exposure concentrations. The maximum concentrations in the study (1.55 mg/m 3 gravimetric, 2328 EU/m 3 endotoxin) were lower than other agricultural or industrial environments. Future work should explore the performance of the prototype sampler in dustier environments, where concentrations approach particulates not otherwise specified (PNOS) limits of 10 mg/m 3 , including using the prototype as a personal sampler.

Glucose monitoring using a polymer brush modified polypropylene hollow fiber-based hydraulic flow sensor.

PubMed

Fortin, Nicolas; Klok, Harm-Anton

2015-03-04

Tight regulation of blood glucose levels of diabetic patients requires durable and robust continuous glucose sensing schemes. This manuscript reports the fabrication of ultrathin, phenylboronic acid (PBA) functionalized polymer brushes that swell upon glucose binding and which were integrated as the sensing interface in a new polypropylene hollow fiber (PPHF)-based hydraulic flow glucose sensor prototype. The polymer brushes were prepared via surface-initiated atom transfer radical polymerization of sodium methacrylate followed by postpolymerization modification with 3-aminophenyl boronic acid. In a first series of experiments, the glucose-response of PBA-functionalized poly(methacrylic acid) (PMAA) brushes grafted from planar silicon surfaces was investigated by quartz crystal microbalance with dissipation (QCM-D) and atomic force microscopy (AFM) experiments. The QCM-D experiments revealed a more or less linear change of the frequency shift for glucose concentrations up to ∼10 mM and demonstrated that glucose binding was completely reversible for up to seven switching cycles. The AFM experiments indicated that glucose binding was accompanied by an increase in the film thickness of the PBA functionalized PMAA brushes. The PBA functionalized PMAA brushes were subsequently grafted from the surface of PPHF membranes. The hydraulic permeability of these porous fibers depends on the thickness and swelling of the PMAA brush coating. PBA functionalized brush-coated PPHFs showed a decrease in flux upon exposure to glucose, which is consistent with swelling of the brush coating. Because they avoid the use of enzymes and do not rely on an electrochemical transduction scheme, these PPHF-based hydraulic flow sensors could represent an interesting alternative class of continuous glucose sensors.

An experimental investigation of wind flow over tall towers in staggered form

NASA Astrophysics Data System (ADS)

Anwar, Proma; Islam, Md. Quamrul; Ali, Mohammad

2016-07-01

In this research work an experiment is conducted to see the effect of wind loading on square, pentagonal and Hexagonal shape cylinders in staggered form. The experiment is done in an open circuit wind tunnel at a Reynolds number of 4.23×104 based on the face width of the cylinder across the flow direction. The flow velocity has been kept uniform throughout the experiment at 14.3 m/s. The test has been conducted for single cylinders first and then in staggered form. Angle of attack is chosen at a definite interval. The static pressure at different locations of the cylinder is measured by inclined multi-manometer. From the surface static pressure readings pressure coefficients are calculated first, then drag and lift coefficients are calculated using numerical Integration Method. These results will surely help engineers to design buildings with such shapes more efficiently. All the results are expressed in non-dimensional form, so they can be applied for prototype buildings and determine the wind loading at any wind speed on structures of similar external shapes.

Investigation of the flow-field of two parallel round jets impinging normal to a flat surface

NASA Astrophysics Data System (ADS)

Myers, Leighton M.

The flow-field features of dual jet impingement were investigated through sub-scale model experiments. The experiments were designed to simulate the environment of a Short Takeoff, and Vertical Landing, STOVL, aircraft performing a hover over the ground, at different heights. Two different dual impinging jet models were designed, fabricated, and tested. The Generation 1 Model consisted of two stainless-steel nozzles, in a tandem configuration, each with an exit diameter of approximately 12.7 mm. The front convergent nozzle was operated at the sonic Mach number of 1.0, while the rear C-D nozzle was generally operated supersonically. The nozzles were embedded in a rectangular flat plate, referred to as the lift plate, which represents a generic lifting surface. The lift plate was instrumented with 36 surface pressure taps, which were used to examine the flow entrainment and recirculation patterns caused by varying the stand-off distance from the nozzle exits to a flat ground surface. The stand-off distance was adjusted with a sliding rail frame that the ground plane was mounted to. Typical dimensionless stand-off distances (ground plane separation) were H/DR = 2 to 24. A series of measurements were performed with the Generation 1 model, in the Penn State High Speed Jet Aeroacoustics Laboratory, to characterize the basic flow phenomena associated with dual jet impingement. The regions of interest in the flow-field included the vertical jet plume(s), near impingement/turning region, and wall jet outwash. Other aspects of interest included the loss of lift (suckdown) that occurs as the ground plane separation distance becomes small, and azimuthal variation of the acoustic noise radiation. Various experimental methods and techniques were used to characterize the flow-field, including flow-visualization, pressure rake surveys, surface mounted pressure taps, laser Doppler velocimetry, and acoustic microphone arrays. A second dual impinging jet scale model, Generation 2, was designed and fabricated with a 50% increase in nozzle exit diameter. The primary design improvement is the ability to quickly and easily exchange the nozzles of the model. This allowed experiments to be performed with rapid-prototyped nozzles that feature more realistic geometry to that of tactical military aircraft engines. One such nozzle, which was designed and demonstrated by previous researchers to reduce jet noise in a free-jet, was incorporated into the model. The nozzle, featuring deflected seals, was installed in the Generation 2 model and its effect on suckdown was evaluated.

Semi-contact-writing of polymer molds for prototyping PDMS chips with low surface roughness, sharp edges and locally varying channel heights

NASA Astrophysics Data System (ADS)

Gutzweiler, Ludwig; Stumpf, Fabian; Tanguy, Laurent; Roth, Guenter; Koltay, Peter; Zengerle, Roland; Riegger, Lutz

2016-04-01

Microfluidic systems fabricated in polydimethylsiloxane (PDMS) enable a broad variety of applications and are widespread in the field of Lab-on-a-Chip. Here we demonstrate semi-contact-writing, a novel method for fabrication of polymer based molds for casting microfluidic PDMS chips in a highly flexible, time and cost-efficient manner. The method is related to direct-writing of an aqueous polymer solution on a planar glass substrate and substitutes conventional, time- and cost-consuming UV-lithography. This technique facilitates on-demand prototyping in a low-cost manner and is therefore ideally suited for rapid chip layout iterations. No cleanroom facilities and less expertise are required. Fabrication time from scratch to ready-to-use PDMS-chip is less than 5 h. This polymer writing method enables structure widths down to 140 μm and controllable structure heights ranging from 5.5 μm for writing single layers up to 98 μm by stacking. As a unique property, freely selectable height variations across a substrate can be achieved by application of local stacking. Furthermore, the molds exhibit low surface roughness (R a   =  24 nm, R RMS  =  28 nm) and high fidelity edge sharpness. We validated the method by fabrication of molds to cast PDMS chips for droplet based flow-through PCR with single-cell sensitivity.

Initial in vitro testing of a paediatric continuous-flow total artificial heart.

PubMed

Fukamachi, Kiyotaka; Karimov, Jamshid H; Horvath, David J; Sunagawa, Gengo; Byram, Nicole A; Kuban, Barry D; Moazami, Nader

2018-06-01

Mechanical circulatory support has become standard therapy for adult patients with end-stage heart failure; however, in paediatric patients with congenital heart disease, the options for chronic mechanical circulatory support are limited to paracorporeal devices or off-label use of devices intended for implantation in adults. Congenital heart disease and cardiomyopathy often involve both the left and right ventricles; in such cases, heart transplantation, a biventricular assist device or a total artificial heart is needed to adequately sustain both pulmonary and systemic circulations. We aimed to evaluate the in vitro performance of the initial prototype of our paediatric continuous-flow total artificial heart. The paediatric continuous-flow total artificial heart pump was downsized from the adult continuous-flow total artificial heart configuration by a scale factor of 0.70 (1/3 of total volume) to enable implantation in infants. System performance of this prototype was evaluated using the continuous-flow total artificial heart mock loop set to mimic paediatric circulation. We generated maps of pump performance and atrial pressure differences over a wide range of systemic vascular resistance/pulmonary vascular resistance and pump speeds. Performance data indicated left pump flow range of 0.4-4.7 l/min at 100 mmHg delta pressure. The left/right atrial pressure difference was maintained within ±5 mmHg with systemic vascular resistance/pulmonary vascular resistance ratios between 1.4 and 35, with/without pump speed modulation, verifying expected passive self-regulation of atrial pressure balance. The paediatric continuous-flow total artificial heart prototype met design requirements for self-regulation and performance; in vivo pump performance studies are ongoing.

CFD analysis of a diaphragm free-piston Stirling cryocooler

NASA Astrophysics Data System (ADS)

Caughley, Alan; Sellier, Mathieu; Gschwendtner, Michael; Tucker, Alan

2016-10-01

This paper presents a Computational Fluid Dynamics (CFD) analysis of a novel free-piston Stirling cryocooler that uses a pair of metal diaphragms to seal and suspend the displacer. The diaphragms allow the displacer to move without rubbing or moving seals. When coupled to a metal diaphragm pressure wave generator, the system produces a complete Stirling cryocooler with no rubbing parts in the working gas space. Initial modelling of this concept using the Sage modelling tool indicated the potential for a useful cryocooler. A proof-of-concept prototype was constructed and achieved cryogenic temperatures. A second prototype was designed and constructed using the experience gained from the first. The prototype produced 29 W of cooling at 77 K and reached a no-load temperature of 56 K. The diaphragm's large diameter and short stroke produces a significant radial component to the oscillating flow fields inside the cryocooler which were not modelled in the one-dimensional analysis tool Sage that was used to design the prototypes. Compared with standard pistons, the diaphragm geometry increases the gas-to-wall heat transfer due to the higher velocities and smaller hydraulic diameters. A Computational Fluid Dynamics (CFD) model of the cryocooler was constructed to understand the underlying fluid-dynamics and heat transfer mechanisms with the aim of further improving performance. The CFD modelling of the heat transfer in the radial flow fields created by the diaphragms shows the possibility of utilizing the flat geometry for heat transfer, reducing the need for, and the size of, expensive heat exchangers. This paper presents details of a CFD analysis used to model the flow and gas-to-wall heat transfer inside the second prototype cryocooler, including experimental validation of the CFD to produce a robust analysis.

DEVELOPMENT OF A LOW-COST INFERENTIAL NATURAL GAS ENERGY FLOW RATE PROTOTYPE RETROFIT MODULE

DOE Office of Scientific and Technical Information (OSTI.GOV)

E. Kelner; T.E. Owen; D.L. George

2004-03-01

In 1998, Southwest Research Institute{reg_sign} began a multi-year project co-funded by the Gas Research Institute (GRI) and the U.S. Department of Energy. The project goal is to develop a working prototype instrument module for natural gas energy measurement. The module will be used to retrofit a natural gas custody transfer flow meter for energy measurement, at a cost an order of magnitude lower than a gas chromatograph. Development and evaluation of the prototype retrofit natural gas energy flow meter in 2000-2001 included: (1) evaluation of the inferential gas energy analysis algorithm using supplemental gas databases and anticipated worst-case gas mixtures;more » (2) identification and feasibility review of potential sensing technologies for nitrogen diluent content; (3) experimental performance evaluation of infrared absorption sensors for carbon dioxide diluent content; and (4) procurement of a custom ultrasonic transducer and redesign of the ultrasonic pulse reflection correlation sensor for precision speed-of-sound measurements. A prototype energy meter module containing improved carbon dioxide and speed-of-sound sensors was constructed and tested in the GRI Metering Research Facility at SwRI. Performance of this module using transmission-quality natural gas and gas containing supplemental carbon dioxide up to 9 mol% resulted in gas energy determinations well within the inferential algorithm worst-case tolerance of {+-}2.4 Btu/scf (nitrogen diluent gas measured by gas chromatograph). A two-week field test was performed at a gas-fired power plant to evaluate the inferential algorithm and the data acquisition requirements needed to adapt the prototype energy meter module to practical field site conditions.« less

Fabrication of slender elastic shells by the coating of curved surfaces

NASA Astrophysics Data System (ADS)

Lee, A.; Brun, P.-T.; Marthelot, J.; Balestra, G.; Gallaire, F.; Reis, P. M.

2016-04-01

Various manufacturing techniques exist to produce double-curvature shells, including injection, rotational and blow molding, as well as dip coating. However, these industrial processes are typically geared for mass production and are not directly applicable to laboratory research settings, where adaptable, inexpensive and predictable prototyping tools are desirable. Here, we study the rapid fabrication of hemispherical elastic shells by coating a curved surface with a polymer solution that yields a nearly uniform shell, upon polymerization of the resulting thin film. We experimentally characterize how the curing of the polymer affects its drainage dynamics and eventually selects the shell thickness. The coating process is then rationalized through a theoretical analysis that predicts the final thickness, in quantitative agreement with experiments and numerical simulations of the lubrication flow field. This robust fabrication framework should be invaluable for future studies on the mechanics of thin elastic shells and their intrinsic geometric nonlinearities.

Propulsion Instruments for Small Hall Thruster Integration

NASA Technical Reports Server (NTRS)

Johnson, Lee K.; Conroy, David G.; Spanjers, Greg G.; Bromaghim, Daron R.

2001-01-01

Planning and development are underway for the propulsion instrumentation necessary for the next AFRL electric propulsion flight project, which includes both a small Hall thruster and a micro-PPT. These instruments characterize the environment induced by the thruster and the associated data constitute part of a 'user's manual' for these thrusters. Several instruments probe the back-flow region of the thruster plume, and the data are intended for comparison with detailed numerical models in this region. Specifically, an ion probe is under development to determine the energy and species distributions, and a Langmuir probe will be employed to characterize the electron density and temperature. Other instruments directly measure the effects of thruster operation on spacecraft thermal control surfaces, optical surfaces, and solar arrays. Specifically, radiometric, photometric, and solar-cell-based sensors are under development. Prototype test data for most sensors should be available, together with details of the instrumentation subsystem and spacecraft interface.

On-Orbit, Immuno-Based, Label-Free White Blood Cell Counting System with Microelectromechanical Sensor Technology (OILWBCS-MEMS)

NASA Technical Reports Server (NTRS)

Edmonds, Jessica

2015-01-01

Aurora Flight Sciences, in partnership with Draper Laboratory, has developed a miniaturized system to count white blood cells in microgravity environments. The system uses MEMS technology to simultaneously count total white blood cells, the five white blood cell differential subgroups, and various lymphocyte subtypes. The OILWBCS-MEMS detection technology works by immobilizing an array of white blood cell-specific antibodies on small, gold-coated membranes. When blood flows across the membranes, specific cells' surface protein antigens bind to their corresponding antibodies. This binding can be measured and correlated to cell counts. In Phase I, the partners demonstrated surface chemistry sensitivity and specificity for total white blood cells and two lymphocyte subtypes. In Phase II, a functional prototype demonstrated end-to-end operation. This rugged, miniaturized device requires minimal blood sample preparation and will be useful for both space flight and terrestrial applications.

Flow networks for Ocean currents

NASA Astrophysics Data System (ADS)

Tupikina, Liubov; Molkenthin, Nora; Marwan, Norbert; Kurths, Jürgen

2014-05-01

Complex networks have been successfully applied to various systems such as society, technology, and recently climate. Links in a climate network are defined between two geographical locations if the correlation between the time series of some climate variable is higher than a threshold. Therefore, network links are considered to imply heat exchange. However, the relationship between the oceanic and atmospheric flows and the climate network's structure is still unclear. Recently, a theoretical approach verifying the correlation between ocean currents and surface air temperature networks has been introduced, where the Pearson correlation networks were constructed from advection-diffusion dynamics on an underlying flow. Since the continuous approach has its limitations, i.e., by its high computational complexity, we here introduce a new, discrete construction of flow-networks, which is then applied to static and dynamic velocity fields. Analyzing the flow-networks of prototypical flows we find that our approach can highlight the zones of high velocity by degree and transition zones by betweenness, while the combination of these network measures can uncover how the flow propagates within time. We also apply the method to time series data of the Equatorial Pacific Ocean Current and the Gulf Stream ocean current for the changing velocity fields, which could not been done before, and analyse the properties of the dynamical system. Flow-networks can be powerful tools to theoretically understand the step from system's dynamics to network's topology that can be analyzed using network measures and is used for shading light on different climatic phenomena.

Chemical vapor deposition fluid flow simulation modelling tool

NASA Technical Reports Server (NTRS)

Bullister, Edward T.

1992-01-01

Accurate numerical simulation of chemical vapor deposition (CVD) processes requires a general purpose computational fluid dynamics package combined with specialized capabilities for high temperature chemistry. In this report, we describe the implementation of these specialized capabilities in the spectral element code NEKTON. The thermal expansion of the gases involved is shown to be accurately approximated by the low Mach number perturbation expansion of the incompressible Navier-Stokes equations. The radiative heat transfer between multiple interacting radiating surfaces is shown to be tractable using the method of Gebhart. The disparate rates of reaction and diffusion in CVD processes are calculated via a point-implicit time integration scheme. We demonstrate the use above capabilities on prototypical CVD applications.

Creation of Prototype Aircrew Protection Equipment Based on Face Anthropometry

DTIC Science & Technology

1993-12-01

AD-A273 865 AFIT/GSE/ENY/93D-2AD 27 86 DTIC ELECTE SDE.C 161993 A : CREATION OF PROTOTYPE AIRCREW PROTECTION EQUIPMENT BASED ON FACE ANTHROPOMETRY ...AIRCREW PROTECTION EQUIPMENT BASED ON FACE ANTHROPOMETRY THESIS Presented to the Faculty of the Graduate School of Engineering of the Air Force Institute...trans- form anthropomorphic surfaces into a prototype mask mold. xix CREATION OF PROTOTYPE AIRCREW PROTECTION EQUIPMENT BASED ON FACE ANTHROPOMETRY L

Synchromodal optical in vivo imaging employing microlens array optics: a complete framework

NASA Astrophysics Data System (ADS)

Peter, Joerg

2013-03-01

A complete mathematical framework for preclinical optical imaging (OI) support comprising bioluminescence imaging (BLI), fluorescence surface imaging (FSI) and fluorescence optical tomography (FOT) is presented in which optical data is acquired by means of a microlens array (MLA) based light detector (MLA-D). The MLA-D has been developed to enable unique OI, especially in synchromodal operation with secondary imaging modalities (SIM) such as positron emission tomography (PET) or magnetic resonance imaging (MRI). An MLA-D consists of a (large-area) photon sensor array, a matched MLA for field-of-view definition, and a septum mask of specific geometry made of anodized aluminum that is positioned between the sensor and the MLA to suppresses light cross-talk and to shield the sensor's radiofrequency interference signal (essential when used inside an MRI system). The software framework, while freely parameterizable for any MLA-D, is tailored towards an OI prototype system for preclinical SIM application comprising a multitude of cylindrically assembled, gantry-mounted, simultaneously operating MLA-D's. Besides the MLA-D specificity, the framework incorporates excitation and illumination light-source declarations of large-field and point geometry to facilitate multispectral FSI and FOT as well as three-dimensional object recognition. When used in synchromodal operation, reconstructed tomographic SIM volume data can be used for co-modal image fusion and also as a prior for estimating the imaged object's 3D surface by means of gradient vector flow. Superimposed planar (without object prior) or surface-aligned inverse mapping can be performed to estimate and to fuse the emission light map with the boundary of the imaged object. Triangulation and subsequent optical reconstruction (FOT) or constrained flow estimation (BLI), both including the possibility of SIM priors, can be performed to estimate the internal three-dimensional emission light distribution. The framework is susceptible to a number of variables controlling convergence and computational speed. Utilization and performance is illustrated on experimentally acquired data employing the OI prototype system in stand-alone operation, and when integrated into an unmodified preclinical PET system performing synchromodal BLI-PET in vivo imaging.

Novel Air Flow Meter for an Automobile Engine Using a Si Sensor with Porous Si Thermal Isolation

PubMed Central

Hourdakis, Emmanouel; Sarafis, Panagiotis; Nassiopoulou, Androula G.

2012-01-01

An air flow meter for measuring the intake air of an automobile engine is presented. It is based on a miniaturized silicon thermal mass flow sensor using a thick porous Si (Po-Si) layer for local thermal isolation from the Si substrate, on which the sensor active elements are integrated. The sensor is mounted on one side of a printed circuit board (PCB), on the other side of which the readout and control electronics of the meter are mounted. The PCB is fixed on a housing containing a semi-cylindrical flow tube, in the middle of which the sensor is situated. An important advantage of the present air flow meter is that it detects with equal sensitivity both forward and reverse flows. Two prototypes were fabricated, a laboratory prototype for flow calibration using mass flow controllers and a final demonstrator with the housing mounted in an automobile engine inlet tube. The final demonstrator was tested in real life conditions in the engine inlet tube of a truck. It shows an almost linear response in a large flow range between –6,500 kg/h and +6,500 kg/h, which is an order of magnitude larger than the ones usually encountered in an automobile engine. PMID:23202189

Novel air flow meter for an automobile engine using a Si sensor with porous Si thermal isolation.

PubMed

Hourdakis, Emmanouel; Sarafis, Panagiotis; Nassiopoulou, Androula G

2012-11-02

An air flow meter for measuring the intake air of an automobile engine is presented. It is based on a miniaturized silicon thermal mass flow sensor using a thick porous Si (Po-Si) layer for local thermal isolation from the Si substrate, on which the sensor active elements are integrated. The sensor is mounted on one side of a printed circuit board (PCB), on the other side of which the readout and control electronics of the meter are mounted. The PCB is fixed on a housing containing a semi-cylindrical flow tube, in the middle of which the sensor is situated. An important advantage of the present air flow meter is that it detects with equal sensitivity both forward and reverse flows. Two prototypes were fabricated, a laboratory prototype for flow calibration using mass flow controllers and a final demonstrator with the housing mounted in an automobile engine inlet tube. The final demonstrator was tested in real life conditions in the engine inlet tube of a truck. It shows an almost linear response in a large flow range between –6,500 kg/h and +6,500 kg/h, which is an order of magnitude larger than the ones usually encountered in an automobile engine.

Evaluation of the Ca ion release, pH and surface apatite formation of a prototype tricalcium silicate cement.

PubMed

Yamamoto, S; Han, L; Noiri, Y; Okiji, T

2017-12-01

To evaluate the Ca 2+ -releasing, alkalizing and apatite-like surface precipitate-forming abilities of a prototype tricalcium silicate cement, which was mainly composed of synthetically prepared tricalcium silicate and zirconium oxide radiopacifier. The prototype tricalcium silicate cement, white ProRoot MTA (WMTA) and TheraCal LC (a light-cured resin-modified calcium silicate-filled material) were examined. The chemical compositions were analysed with a wavelength-dispersive X-ray spectroscopy electron probe microanalyser with an image observation function (SEM-EPMA). The pH and Ca 2+ concentrations of water in which the set materials had been immersed were measured, and the latter was assessed with the EDTA titration method. The surface precipitates formed on the materials immersed in phosphate-buffered saline (PBS) were analysed with SEM-EPMA and X-ray diffraction (XRD). Kruskal-Wallis tests followed by Mann-Whitney U-test with Bonferroni correction were used for statistical analysis (α = 0.05). The prototype cement contained Ca, Si and Zr as major elemental constituents, whereas it did not contain some metal elements that were detected in the other materials. The Ca 2+ concentrations and pH of the immersion water samples exhibited the following order: WMTA = prototype cement > TheraCal LC (P < 0.05). All three materials produced Ca- and P-containing surface precipitates after PBS immersion, and the precipitates produced by TheraCal LC displayed lower Ca/P ratios than those formed by the other materials. XRD peaks corresponding to hydroxyapatite were detected in the precipitates produced by the prototype cement and WMTA. The prototype tricalcium silicate cement exhibited similar Ca 2+ -releasing, alkalizing and apatite-like precipitate-forming abilities to WMTA. The Ca 2+ -releasing, alkalizing and apatite-like precipitate-forming abilities of TheraCal LC were lower than those of the other materials. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

A microfluidic fuel cell with flow-through porous electrodes.

PubMed

Kjeang, Erik; Michel, Raphaelle; Harrington, David A; Djilali, Ned; Sinton, David

2008-03-26

A microfluidic fuel cell architecture incorporating flow-through porous electrodes is demonstrated. The design is based on cross-flow of aqueous vanadium redox species through the electrodes into an orthogonally arranged co-laminar exit channel, where the waste solutions provide ionic charge transfer in a membraneless configuration. This flow-through architecture enables improved utilization of the three-dimensional active area inside the porous electrodes and provides enhanced rates of convective/diffusive transport without increasing the parasitic loss required to drive the flow. Prototype fuel cells are fabricated by rapid prototyping with total material cost estimated at 2 USD/unit. Improved performance as compared to previous microfluidic fuel cells is demonstrated, including power densities at room temperature up to 131 mW cm-2. In addition, high overall energy conversion efficiency is obtained through a combination of relatively high levels of fuel utilization and cell voltage. When operated at 1 microL min-1 flow rate, the fuel cell produced 20 mW cm-2 at 0.8 V combined with an active fuel utilization of 94%. Finally, we demonstrate in situ fuel and oxidant regeneration by running the flow-through architecture fuel cell in reverse.

Cyber Situational Awareness through Operational Streaming Analysis

DTIC Science & Technology

2011-04-07

Our system makes use of two specific data sources from network traffic: raw packet data and NetFlow connection summary records (de- scribed below...implemented an operational prototype system using the following two data feeds. a) NetFlow Data: Our system processes the NetFlow records of all...Internet gateway traffic for a large enterprise network. It uses the standard Cisco NetFlow version 5 proto- col, which defines a flow as a

16 CFR 309.21 - Labeling requirements for used covered vehicles.

Code of Federal Regulations, 2010 CFR

2010-01-01

... visible surface of each such vehicle. (b) Layout. Figure 6 of appendix A is the prototype label that... consistent with the prototype label. The label required by this section is one-sided and rectangular in shape... label. Specific type sizes and faces to be used are indicated on the prototype label (Figure 6 of...

Full area covered 3D profile measurement of special-shaped optics based on a new prototype non-contact profiler

NASA Astrophysics Data System (ADS)

Du, Hui-Lin; Zhou, Zhao-Zhong; Sun, Ze-Qing; Ju, Bing-Feng; Xu, Shaoning; Sun, Anyu

2017-06-01

A new prototype non-contact profiler based on surface tracking has been specially developed. Surface tracking is carried out by a specially designed dual stage probe system with the aid of a four-Degree Of Freedom high-precision motion platform. The dual stage probe system keeps a short-range optical probe constantly tracking the surface by a self-developed voice coil motor servo, by which a wide measuring range of up to 10 mm is realized. The system performance evaluation including resolution, repeatability, and scanning speed proved the good capability of the new prototype non-contact profiler. To realize a full area covered 3D profile measurement of special-shaped optics within one scanning procedure, a signal intensity monitor integrated in the surface tracking controller is specially developed. In the experiment, a snip-single-corner-rectangular-shaped freeform surface was successfully measured over full area by the new non-contact profiler. This work provides an effective solution for 3D profile measurement of special-shaped optical surfaces over full reflecting area. Experimental results demonstrate that the proposed measuring system is of great significance in quality evaluation of optical surfaces.

Full area covered 3D profile measurement of special-shaped optics based on a new prototype non-contact profiler.

PubMed

Du, Hui-Lin; Zhou, Zhao-Zhong; Sun, Ze-Qing; Ju, Bing-Feng; Xu, Shaoning; Sun, Anyu

2017-06-01

A new prototype non-contact profiler based on surface tracking has been specially developed. Surface tracking is carried out by a specially designed dual stage probe system with the aid of a four-Degree Of Freedom high-precision motion platform. The dual stage probe system keeps a short-range optical probe constantly tracking the surface by a self-developed voice coil motor servo, by which a wide measuring range of up to 10 mm is realized. The system performance evaluation including resolution, repeatability, and scanning speed proved the good capability of the new prototype non-contact profiler. To realize a full area covered 3D profile measurement of special-shaped optics within one scanning procedure, a signal intensity monitor integrated in the surface tracking controller is specially developed. In the experiment, a snip-single-corner-rectangular-shaped freeform surface was successfully measured over full area by the new non-contact profiler. This work provides an effective solution for 3D profile measurement of special-shaped optical surfaces over full reflecting area. Experimental results demonstrate that the proposed measuring system is of great significance in quality evaluation of optical surfaces.

Development of liquid-lithium film jet-flow for the target of (7)Li(p,n)(7)Be reactions for BNCT.

PubMed

Kobayashi, Tooru; Miura, Kuniaki; Hayashizaki, Noriyosu; Aritomi, Masanori

2014-06-01

A feasibility study on liquid lithium target in the form of a flowing film was performed to evaluate its potential use as a neutron generation target of (7)Li(p,n)(7)Be reaction in BNCT. The target is a windowless-type flowing film on a concave wall. Its configuration was adapted for a proton beam which is 30mm in diameter and with energy and current of up to 3MeV and 20mA, respectively. The flowing film of liquid lithium was 0.6mm in thickness, 50mm in width and 50mm in length. The shapes of the nozzle and concave back wall, which create a stable flowing film jet, were decided based on water experiments. A lithium hydrodynamic experiment was performed to observe the stability of liquid lithium flow behavior. The flowing film of liquid lithium was found to be feasible at temperatures below the liquid lithium boiling saturation of 342°C at the surface pressure of 1×10(-3)Pa. Using a proto-type liquid lithium-circulating loop for BNCT, the stability of the film flow was confirmed for velocities up to 30m/s at 220°C and 250°C in vacuum at a pressure lower than 10(-3) Pa. It is expected that for practical use, a flowing liquid lithium target of a windowless type can solve the problem of radiation damage and target cooling. Copyright © 2013 Elsevier Ltd. All rights reserved.

In-Bed Accountability Development for a Passively Cooled, Electrically Heated Hydride (PACE) Bed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klein, J.E.

A nominal 1500 STP-L PAssively Cooled, Electrically heated hydride (PACE) Bed has been developed for implementation into a new Savannah River Site tritium project. The 1.2 meter (four-foot) long process vessel contains on internal 'U-tube' for tritium In-Bed Accountability (IBA) measurements. IBA will be performed on six, 12.6 kg production metal hydride storage beds.IBA tests were done on a prototype bed using electric heaters to simulate the radiolytic decay of tritium. Tests had gas flows from 10 to 100 SLPM through the U-tube or 100 SLPM through the bed's vacuum jacket. IBA inventory measurement errors at the 95% confidence levelmore » were calculated using the correlation of IBA gas temperature rise, or (hydride) bed temperature rise above ambient temperature, versus simulated tritium inventory.Prototype bed IBA inventory errors at 100 SLPM were the largest for gas flows through the vacuum jacket: 15.2 grams for the bed temperature rise and 11.5 grams for the gas temperature rise. For a 100 SLPM U-tube flow, the inventory error was 2.5 grams using bed temperature rise and 1.6 grams using gas temperature rise. For 50 to 100 SLPM U-tube flows, the IBA gas temperature rise inventory errors were nominally one to two grams that increased above four grams for flows less than 50 SLPM. For 50 to 100 SLPM U-tube flows, the IBA bed temperature rise inventory errors were greater than the gas temperature rise errors, but similar errors were found for both methods at gas flows of 20, 30, and 40 SLPM.Electric heater IBA tests were done for six production hydride beds using a 45 SLPM U-tube gas flow. Of the duplicate runs performed on these beds, five of the six beds produced IBA inventory errors of approximately three grams: consistent with results obtained in the laboratory prototype tests.« less

In-Bed Accountability Development for a Passively Cooled, Electrically Heated Hydride (PACE) Bed

DOE Office of Scientific and Technical Information (OSTI.GOV)

KLEIN, JAMES

A nominal 1500 STP-L PAssively Cooled, Electrically heated hydride (PACE) Bed has been developed for implementation into a new Savannah River Site tritium project. The 1.2 meter (four-foot) long process vessel contains an internal ''U-tube'' for tritium In-Bed Accountability (IBA) measurements. IBA will be performed on six, 12.6 kg production metal hydride storage beds. IBA tests were done on a prototype bed using electric heaters to simulate the radiolytic decay of tritium. Tests had gas flows from 10 to 100 SLPM through the U-tube or 100 SLPM through the bed's vacuum jacket. IBA inventory measurement errors at the 95 percentmore » confidence level were calculated using the correlation of IBA gas temperature rise, or (hydride) bed temperature rise above ambient temperature, versus simulated tritium inventory. Prototype bed IBA inventory errors at 100 SLPM were the largest for gas flows through the vacuum jacket: 15.2 grams for the bed temperature rise and 11.5 grams for the gas temperature rise. For a 100 SLPM U-tube flow, the inventory error was 2.5 grams using bed temperature rise and 1.6 grams using gas temperature rise. For 50 to 100 SLPM U-tube flows, the IBA gas temperature rise inventory errors were nominally one to two grams that increased above four grams for flows less than 50 SLPM. For 50 to 100 SLPM U-tube flows, the IBA bed temperature rise inventory errors were greater than the gas temperature rise errors, but similar errors were found for both methods at gas flows of 20, 30, and 40 SLPM. Electric heater IBA tests were done for six production hydride beds using a 45 SLPM U-tube gas flow. Of the duplicate runs performed on these beds, five of the six beds produced IBA inventory errors of approximately three grams: consistent with results obtained in the laboratory prototype tests.« less

A computational model for three-dimensional incompressible wall jets with large cross flow

NASA Technical Reports Server (NTRS)

Murphy, W. D.; Shankar, V.; Malmuth, N. D.

1979-01-01

A computational model for the flow field of three dimensional incompressible wall jets prototypic of thrust augmenting ejectors with large cross flow is presented. The formulation employs boundary layer equations in an orthogonal curvilinear coordinate system. Simulation of laminar as well as turbulen wall jets is reported. Quantification of jet spreading, jet growth, nominal separation, and jet shrink effects due to corss flow are discussed.

A Design Study Investigating Augmented Reality and Photograph Annotation in a Digitalized Grossing Workstation

PubMed Central

Chow, Joyce A.; Törnros, Martin E.; Waltersson, Marie; Richard, Helen; Kusoffsky, Madeleine; Lundström, Claes F.; Kurti, Arianit

2017-01-01

Context: Within digital pathology, digitalization of the grossing procedure has been relatively underexplored in comparison to digitalization of pathology slides. Aims: Our investigation focuses on the interaction design of an augmented reality gross pathology workstation and refining the interface so that information and visualizations are easily recorded and displayed in a thoughtful view. Settings and Design: The work in this project occurred in two phases: the first phase focused on implementation of an augmented reality grossing workstation prototype while the second phase focused on the implementation of an incremental prototype in parallel with a deeper design study. Subjects and Methods: Our research institute focused on an experimental and “designerly” approach to create a digital gross pathology prototype as opposed to focusing on developing a system for immediate clinical deployment. Statistical Analysis Used: Evaluation has not been limited to user tests and interviews, but rather key insights were uncovered through design methods such as “rapid ethnography” and “conversation with materials”. Results: We developed an augmented reality enhanced digital grossing station prototype to assist pathology technicians in capturing data during examination. The prototype uses a magnetically tracked scalpel to annotate planned cuts and dimensions onto photographs taken of the work surface. This article focuses on the use of qualitative design methods to evaluate and refine the prototype. Our aims were to build on the strengths of the prototype's technology, improve the ergonomics of the digital/physical workstation by considering numerous alternative design directions, and to consider the effects of digitalization on personnel and the pathology diagnostics information flow from a wider perspective. A proposed interface design allows the pathology technician to place images in relation to its orientation, annotate directly on the image, and create linked information. Conclusions: The augmented reality magnetically tracked scalpel reduces tool switching though limitations in today's augmented reality technology fall short of creating an ideal immersive workflow by requiring the use of a monitor. While this technology catches up, we recommend focusing efforts on enabling the easy creation of layered, complex reports, linking, and viewing information across systems. Reflecting upon our results, we argue for digitalization to focus not only on how to record increasing amounts of data but also how these data can be accessed in a more thoughtful way that draws upon the expertise and creativity of pathology professionals using the systems. PMID:28966831

A Design Study Investigating Augmented Reality and Photograph Annotation in a Digitalized Grossing Workstation.

PubMed

Chow, Joyce A; Törnros, Martin E; Waltersson, Marie; Richard, Helen; Kusoffsky, Madeleine; Lundström, Claes F; Kurti, Arianit

2017-01-01

Within digital pathology, digitalization of the grossing procedure has been relatively underexplored in comparison to digitalization of pathology slides. Our investigation focuses on the interaction design of an augmented reality gross pathology workstation and refining the interface so that information and visualizations are easily recorded and displayed in a thoughtful view. The work in this project occurred in two phases: the first phase focused on implementation of an augmented reality grossing workstation prototype while the second phase focused on the implementation of an incremental prototype in parallel with a deeper design study. Our research institute focused on an experimental and "designerly" approach to create a digital gross pathology prototype as opposed to focusing on developing a system for immediate clinical deployment. Evaluation has not been limited to user tests and interviews, but rather key insights were uncovered through design methods such as " rapid ethnography " and " conversation with materials ". We developed an augmented reality enhanced digital grossing station prototype to assist pathology technicians in capturing data during examination. The prototype uses a magnetically tracked scalpel to annotate planned cuts and dimensions onto photographs taken of the work surface. This article focuses on the use of qualitative design methods to evaluate and refine the prototype. Our aims were to build on the strengths of the prototype's technology, improve the ergonomics of the digital/physical workstation by considering numerous alternative design directions, and to consider the effects of digitalization on personnel and the pathology diagnostics information flow from a wider perspective. A proposed interface design allows the pathology technician to place images in relation to its orientation, annotate directly on the image, and create linked information. The augmented reality magnetically tracked scalpel reduces tool switching though limitations in today's augmented reality technology fall short of creating an ideal immersive workflow by requiring the use of a monitor. While this technology catches up, we recommend focusing efforts on enabling the easy creation of layered, complex reports, linking, and viewing information across systems. Reflecting upon our results, we argue for digitalization to focus not only on how to record increasing amounts of data but also how these data can be accessed in a more thoughtful way that draws upon the expertise and creativity of pathology professionals using the systems.

Periodic magnetorotational dynamo action as a prototype of nonlinear magnetic-field generation in shear flows.

PubMed

Herault, J; Rincon, F; Cossu, C; Lesur, G; Ogilvie, G I; Longaretti, P-Y

2011-09-01

The nature of dynamo action in shear flows prone to magnetohydrodynamc instabilities is investigated using the magnetorotational dynamo in Keplerian shear flow as a prototype problem. Using direct numerical simulations and Newton's method, we compute an exact time-periodic magnetorotational dynamo solution to three-dimensional dissipative incompressible magnetohydrodynamic equations with rotation and shear. We discuss the physical mechanism behind the cycle and show that it results from a combination of linear and nonlinear interactions between a large-scale axisymmetric toroidal magnetic field and nonaxisymmetric perturbations amplified by the magnetorotational instability. We demonstrate that this large-scale dynamo mechanism is overall intrinsically nonlinear and not reducible to the standard mean-field dynamo formalism. Our results therefore provide clear evidence for a generic nonlinear generation mechanism of time-dependent coherent large-scale magnetic fields in shear flows and call for new theoretical dynamo models. These findings may offer important clues to understanding the transitional and statistical properties of subcritical magnetorotational turbulence.

A Prototype Land Information Sensor Web: Design, Implementation and Implication for the SMAP Mission

NASA Astrophysics Data System (ADS)

Su, H.; Houser, P.; Tian, Y.; Geiger, J. K.; Kumar, S. V.; Gates, L.

2009-12-01

Land Surface Model (LSM) predictions are regular in time and space, but these predictions are influenced by errors in model structure, input variables, parameters and inadequate treatment of sub-grid scale spatial variability. Consequently, LSM predictions are significantly improved through observation constraints made in a data assimilation framework. Several multi-sensor satellites are currently operating which provide multiple global observations of the land surface, and its related near-atmospheric properties. However, these observations are not optimal for addressing current and future land surface environmental problems. To meet future earth system science challenges, NASA will develop constellations of smart satellites in sensor web configurations which provide timely on-demand data and analysis to users, and can be reconfigured based on the changing needs of science and available technology. A sensor web is more than a collection of satellite sensors. That means a sensor web is a system composed of multiple platforms interconnected by a communication network for the purpose of performing specific observations and processing data required to support specific science goals. Sensor webs can eclipse the value of disparate sensor components by reducing response time and increasing scientific value, especially when the two-way interaction between the model and the sensor web is enabled. The study of a prototype Land Information Sensor Web (LISW) is sponsored by NASA, trying to integrate the Land Information System (LIS) in a sensor web framework which allows for optimal 2-way information flow that enhances land surface modeling using sensor web observations, and in turn allows sensor web reconfiguration to minimize overall system uncertainty. This prototype is based on a simulated interactive sensor web, which is then used to exercise and optimize the sensor web modeling interfaces. The Land Information Sensor Web Service-Oriented Architecture (LISW-SOA) has been developed and it is the very first sensor web framework developed especially for the land surface studies. Synthetic experiments based on the LISW-SOA and the virtual sensor web provide a controlled environment in which to examine the end-to-end performance of the prototype, the impact of various sensor web design trade-offs and the eventual value of sensor webs for a particular prediction or decision support. In this paper, the design, implementation of the LISW-SOA and the implication for the Soil Moisture Active and Passive (SMAP) mission is presented. Particular attention is focused on examining the relationship between the economic investment on a sensor web (space and air borne, ground based) and the accuracy of the model predicted soil moisture, which can be achieved by using such sensor observations. The Study of Virtual Land Information Sensor Web (LISW) is expected to provide some necessary a priori knowledge for designing and deploying the next generation Global Earth Observing System of systems (GEOSS).

Design of a solar concentrator considering arbitrary surfaces

NASA Astrophysics Data System (ADS)

Jiménez-Rodríguez, Martín.; Avendaño-Alejo, Maximino; Verduzco-Grajeda, Lidia Elizabeth; Martínez-Enríquez, Arturo I.; García-Díaz, Reyes; Díaz-Uribe, Rufino

2017-10-01

We study the propagation of light in order to efficiently redirect the reflected light on photocatalytic samples placed inside a commercial solar simulator, and we have designed a small-scale prototype of Cycloidal Collectors (CCs), resembling a compound parabolic collector. The prototype consists of either cycloidal trough or cycloidal collector having symmetry of rotation, which has been designed considering an exact ray tracing assuming a bundle of rays propagating parallel to the optical axis and impinging on a curate cycloidal surface, obtaining its caustic surface produced by reflection.

Setup and evaluation of a sensor tilting system for dimensional micro- and nanometrology

NASA Astrophysics Data System (ADS)

Schuler, Alexander; Weckenmann, Albert; Hausotte, Tino

2014-06-01

Sensors in micro- and nanometrology show their limits if the measurement objects and surfaces feature high aspect ratios, high curvature and steep surface angles. Their measurable surface angle is limited and an excess leads to measurement deviation and not detectable surface points. We demonstrate a principle to adapt the sensor's working angle during the measurement keeping the sensor in its optimal working angle. After the simulation of the principle, a hardware prototype was realized. It is based on a rotary kinematic chain with two rotary degrees of freedom, which extends the measurable surface angle to ±90° and is combined with a nanopositioning and nanomeasuring machine. By applying a calibration procedure with a quasi-tactile 3D sensor based on electrical near-field interaction the systematic position deviation of the kinematic chain is reduced. The paper shows for the first time the completed setup and integration of the prototype, the performance results of the calibration, the measurements with the prototype and the tilting principle, and finishes with the interpretation and feedback of the practical results.

Applying NISHIJIN historical textile technique for e-Textile.

PubMed

Kuroda, Tomohiro; Hirano, Kikuo; Sugimura, Kazushige; Adachi, Satoshi; Igarashi, Hidetsugu; Ueshima, Kazuo; Nakamura, Hideo; Nambu, Masayuki; Doi, Takahiro

2013-01-01

The e-Textile is the key technology for continuous ambient health monitoring to increase quality of life of patients with chronic diseases. The authors introduce techniques of Japanese historical textile, NISHIJIN, which illustrate almost any pattern from one continuous yarn within the machine weaving process, which is suitable for mixed flow production. Thus, NISHIJIN is suitable for e-Textile production, which requires rapid prototyping and mass production of very complicated patterns. The authors prototyped and evaluated a few vests to take twelve-lead electrocardiogram. The result tells that the prototypes obtains electrocardiogram, which is good enough for diagnosis.

Advances in Automated Plankton Imaging: Enhanced Throughput, Automated Staining, and Extended Deployment Modes for Imaging FlowCytobot

NASA Astrophysics Data System (ADS)

Sosik, H. M.; Olson, R. J.; Brownlee, E.; Brosnahan, M.; Crockford, E. T.; Peacock, E.; Shalapyonok, A.

2016-12-01

Imaging FlowCytobot (IFCB) was developed to fill a need for automated identification and monitoring of nano- and microplankton, especially phytoplankton in the size range 10 200 micrometer, which are important in coastal blooms (including harmful algal blooms). IFCB uses a combination of flow cytometric and video technology to capture high resolution (1 micrometer) images of suspended particles. This proven, now commercially available, submersible instrument technology has been deployed in fixed time series locations for extended periods (months to years) and in shipboard laboratories where underway water is automatically analyzed during surveys. Building from these successes, we have now constructed and evaluated three new prototype IFCB designs that extend measurement and deployment capabilities. To improve cell counting statistics without degrading image quality, a high throughput version (IFCB-HT) incorporates in-flow acoustic focusing to non-disruptively pre-concentrate cells before the measurement area of the flow cell. To extend imaging to all heterotrophic cells (even those that do not exhibit chlorophyll fluorescence), Staining IFCB (IFCB-S) incorporates automated addition of a live-cell fluorescent stain (fluorescein diacetate) to samples before analysis. A horizontally-oriented IFCB-AV design addresses the need for spatial surveying from surface autonomous vehicles, including design features that reliably eliminate air bubbles and mitigate wave motion impacts. Laboratory evaluation and test deployments in waters near Woods Hole show the efficacy of each of these enhanced IFCB designs.

A full three dimensional Navier-Stokes numerical simulation of flow field inside a power plant Kaplan turbine using some model test turbine hill chart points

NASA Astrophysics Data System (ADS)

Hosseinalipour, S. M.; Raja, A.; Hajikhani, S.

2012-06-01

A full three dimensional Navier - Stokes numerical simulation has been performed for performance analysis of a Kaplan turbine which is installed in one of the Irans south dams. No simplifications have been enforced in the simulation. The numerical results have been evaluated using some integral parameters such as the turbine efficiency via comparing the results with existing experimental data from the prototype Hill chart. In part of this study the numerical simulations were performed in order to calculate the prototype turbine efficiencies in some specific points which comes from the scaling up of the model efficiency that are available in the model experimental Hill chart. The results are very promising which shows the good ability of the numerical techniques for resolving the flow characteristics in these kind of complex geometries. A parametric study regarding the evaluation of turbine performance in three different runner angles of the prototype is also performed and the results are cited in this paper.

Initial Operation and Shakedown of the Nuclear Thermal Rocket Element Environmental Simulator (NTREES)

NASA Technical Reports Server (NTRS)

Emrich, William J., Jr.

2014-01-01

To support the on-going nuclear thermal propulsion effort, a state-of-the-art non nuclear experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The facility to perform this testing is referred to as the Nuclear Thermal Rocket Element Environment Simulator (NTREES). This device can simulate the environmental conditions (minus the radiation) to which nuclear rocket fuel components will be subjected during reactor operation. Prototypical fuel elements mounted in the simulator are inductively heated in such a manner so as to accurately reproduce the temperatures and heat fluxes which would normally occur as a result of nuclear fission in addition to being exposed to flowing hydrogen. Recent upgrades to NTREES now allow power levels 24 times greater than those achievable in the previous facility configuration. This higher power operation will allow near prototypical power densities and flows to finally be achieved in most prototypical fuel elements.

Computation and analysis of cavitating flow in Francis-class hydraulic turbines

NASA Astrophysics Data System (ADS)

Leonard, Daniel J.

Hydropower is the most proven renewable energy technology, supplying the world with 16% of its electricity. Conventional hydropower generates a vast majority of that percentage. Although a mature technology, hydroelectric generation shows great promise for expansion through new dams and plants in developing hydro countries. Moreover, in developed hydro countries, such as the United States, installing generating units in existing dams and the modern refurbishment of existing plants can greatly expand generating capabilities with little to no further impact on the environment. In addition, modern computational technology and fluid dynamics expertise has led to substantial improvements in modern turbine design and performance. Cavitation has always presented a problem in hydroturbines, causing performance breakdown, erosion, damage, vibration, and noise. While modern turbines are usually designed to be cavitation-free at their best efficiency point, due to the variable demand of the energy market it is fairly common to operate at off-design conditions. Here, cavitation and its deleterious effects are unavoidable, and hence, cavitation is a limiting factor on the design and operation of these turbines. Multiphase Computational Fluid Dynamics (CFD) has been used in recent years to model cavitating flow for a large range of problems, including turbomachinery. However, CFD of cavitating flow in hydroturbines is still in its infancy. This dissertation presents steady-periodic Reynolds-averaged Navier-Stokes simulations of a cavitating Francis-class hydroturbine at model and prototype scales. Computational results of the reduced-scale model and full-scale prototype, undergoing performance breakdown, are compared with empirical model data and prototype performance estimations based on standard industry scalings from the model data. Mesh convergence of the simulations is also displayed. Comparisons are made between the scales to display that cavitation performance breakdown can occur more abruptly in the model than the prototype, due to lack of Froude similitude between the two. When severe cavitation occurs, clear differences are observed in vapor content between the scales. A stage-by-stage performance decomposition is conducted to analyze the losses within individual components of each scale of the machine. As cavitation becomes more severe, the losses in the draft tube account for an increasing amount of the total losses in the machine. More losses occur in the model draft tube as cavitation formation in the prototype draft tube is prevented by the larger hydrostatic pressure gradient across the machine. Additionally, unsteady Detached Eddy Simulations of the fully-coupled cavitating hydroturbine are performed for both scales. Both mesh and temporal convergence studies are provided. The temporal and spectral content of fluctuations in torque and pressure are monitored and compared between single-phase, cavitating, model, and prototype cases. A shallow draft tube induced runner imbalance results in an asymmetric vapor distribution about the runner, leading to more extensive growth and collapse of vapor on any individual blade as it undergoes a revolution. Unique frequency components manifest and persist through the entire machine only when cavitation is present in the hub vortex. Large maximum pressure spikes, which result from vapor collapse, are observed on the blade surfaces in the multiphase simulations, and these may be a potential source of cavitation damage and erosion. Multiphase CFD is shown to be an accurate and effective technique for simulating and analyzing cavitating flow in Francis-class hydraulic turbines. It is recommended that it be used as an industrial tool to supplement model cavitation experiments for all types of hydraulic turbines. Moreover, multiphase CFD can be equally effective as a research tool, to investigate mechanisms of cavitating hydraulic turbines that are not understood, and to uncover unique new phenomena which are currently unknown.

Computational Fluid Dynamics (CFD) study of the 4th generation prototype of a continuous flow Ventricular Assist Device (VAD).

PubMed

Song, Xinwei; Wood, Houston G; Olsen, Don

2004-04-01

The continuous flow ventricular assist device (VAD) is a miniature centrifugal pump, fully suspended by magnetic bearings, which is being developed for implantation in humans. The CF4 model is the first actual prototype of the final design product. The overall performances of blood flow in CF4 have been simulated using computational fluid dynamics (CFD) software: CFX, which is commercially available from ANSYS Inc. The flow regions modeled in CF4 include the inlet elbow, the five-blade impeller, the clearance gap below the impeller, and the exit volute. According to different needs from patients, a wide range of flow rates and revolutions per minute (RPM) have been studied. The flow rate-pressure curves are given. The streamlines in the flow field are drawn to detect stagnation points and vortices that could lead to thrombosis. The stress is calculated in the fluid field to estimate potential hemolysis. The stress is elevated to the decreased size of the blood flow paths through the smaller pump, but is still within the safe range. The thermal study on the pump, the blood and the surrounding tissue shows the temperature rise due to magnetoelectric heat sources and thermal dissipation is insignificant. CFD simulation proved valuable to demonstrate and to improve the performance of fluid flow in the design of a small size pump.

A new UV-curing elastomeric substrate for rapid prototyping of microfluidic devices

NASA Astrophysics Data System (ADS)

Alvankarian, Jafar; Yeop Majlis, Burhanuddin

2012-03-01

Rapid prototyping in the design cycle of new microfluidic devices is very important for shortening time-to-market. Researchers are facing the challenge to explore new and suitable substrates with simple and efficient microfabrication techniques. In this paper, we introduce and characterize a UV-curing elastomeric polyurethane methacrylate (PUMA) for rapid prototyping of microfluidic devices. The swelling and solubility of PUMA in different chemicals is determined. Time-dependent measurements of water contact angle show that the native PUMA is hydrophilic without surface treatment. The current monitoring method is used for measurement of the electroosmotic flow mobility in the microchannels made from PUMA. The optical, physical, thermal and mechanical properties of PUMA are evaluated. The UV-lithography and molding process is used for making micropillars and deep channel microfluidic structures integrated to the supporting base layer. Spin coating is characterized for producing different layer thicknesses of PUMA resin. A device is fabricated and tested for examining the strength of different bonding techniques such as conformal, corona treating and semi-curing of two PUMA layers in microfluidic application and the results show that the bonding strengths are comparable to that of PDMS. We also report fabrication and testing of a three-layer multi inlet/outlet microfluidic device including a very effective fluidic interconnect for application demonstration of PUMA as a promising new substrate. A simple micro-device is developed and employed for observing the pressure deflection of membrane made from PUMA as a very effective elastomeric valve in microfluidic devices.

Computational Aerodynamic Analysis of Three-Dimensional Ice Shapes on a NACA 23012 Airfoil

NASA Technical Reports Server (NTRS)

Jun, GaRam; Oliden, Daniel; Potapczuk, Mark G.; Tsao, Jen-Ching

2014-01-01

The present study identifies a process for performing computational fluid dynamic calculations of the flow over full three-dimensional (3D) representations of complex ice shapes deposited on aircraft surfaces. Rime and glaze icing geometries formed on a NACA23012 airfoil were obtained during testing in the NASA Glenn Research Centers Icing Research Tunnel (IRT). The ice shape geometries were scanned as a cloud of data points using a 3D laser scanner. The data point clouds were meshed using Geomagic software to create highly accurate models of the ice surface. The surface data was imported into Pointwise grid generation software to create the CFD surface and volume grids. It was determined that generating grids in Pointwise for complex 3D icing geometries was possible using various techniques that depended on the ice shape. Computations of the flow fields over these ice shapes were performed using the NASA National Combustion Code (NCC). Results for a rime ice shape for angle of attack conditions ranging from 0 to 10 degrees and for freestream Mach numbers of 0.10 and 0.18 are presented. For validation of the computational results, comparisons were made to test results from rapid-prototype models of the selected ice accretion shapes, obtained from a separate study in a subsonic wind tunnel at the University of Illinois at Urbana-Champaign. The computational and experimental results were compared for values of pressure coefficient and lift. Initial results show fairly good agreement for rime ice accretion simulations across the range of conditions examined. The glaze ice results are promising but require some further examination.

Computational Aerodynamic Analysis of Three-Dimensional Ice Shapes on a NACA 23012 Airfoil

NASA Technical Reports Server (NTRS)

Jun, Garam; Oliden, Daniel; Potapczuk, Mark G.; Tsao, Jen-Ching

2014-01-01

The present study identifies a process for performing computational fluid dynamic calculations of the flow over full three-dimensional (3D) representations of complex ice shapes deposited on aircraft surfaces. Rime and glaze icing geometries formed on a NACA23012 airfoil were obtained during testing in the NASA Glenn Research Center's Icing Research Tunnel (IRT). The ice shape geometries were scanned as a cloud of data points using a 3D laser scanner. The data point clouds were meshed using Geomagic software to create highly accurate models of the ice surface. The surface data was imported into Pointwise grid generation software to create the CFD surface and volume grids. It was determined that generating grids in Pointwise for complex 3D icing geometries was possible using various techniques that depended on the ice shape. Computations of the flow fields over these ice shapes were performed using the NASA National Combustion Code (NCC). Results for a rime ice shape for angle of attack conditions ranging from 0 to 10 degrees and for freestream Mach numbers of 0.10 and 0.18 are presented. For validation of the computational results, comparisons were made to test results from rapid-prototype models of the selected ice accretion shapes, obtained from a separate study in a subsonic wind tunnel at the University of Illinois at Urbana-Champaign. The computational and experimental results were compared for values of pressure coefficient and lift. Initial results show fairly good agreement for rime ice accretion simulations across the range of conditions examined. The glaze ice results are promising but require some further examination.

Effects of perforation number of blade on aerodynamic performance of dual-rotor small axial flow fans

NASA Astrophysics Data System (ADS)

Hu, Yongjun; Wang, Yanping; Li, Guoqi; Jin, Yingzi; Setoguchi, Toshiaki; Kim, Heuy Dong

2015-04-01

Compared with single rotor small axial flow fans, dual-rotor small axial flow fans is better regarding the static characteristics. But the aerodynamic noise of dual-rotor small axial flow fans is worse than that of single rotor small axial flow fans. In order to improve aerodynamic noise of dual-rotor small axial flow fans, the pre-stage blades with different perforation numbers are designed in this research. The RANS equations and the standard k-ɛ turbulence model as well as the FW-H noise model are used to simulate the flow field within the fan. Then, the aerodynamic performance of the fans with different perforation number is compared and analyzed. The results show that: (1) Compared to the prototype fan, the noise of fans with perforation blades is reduced. Additionally, the noise of the fans decreases with the increase of the number of perforations. (2) The vorticity value in the trailing edge of the pre-stage blades of perforated fans is reduced. It is found that the vorticity value in the trailing edge of the pre-stage blades decreases with the increase of the number of perforations. (3) Compared to the prototype fan, the total pressure rising and efficiency of the fans with perforation blades drop slightly.

The MARS2013 Mars analog mission.

PubMed

Groemer, Gernot; Soucek, Alexander; Frischauf, Norbert; Stumptner, Willibald; Ragonig, Christoph; Sams, Sebastian; Bartenstein, Thomas; Häuplik-Meusburger, Sandra; Petrova, Polina; Evetts, Simon; Sivenesan, Chan; Bothe, Claudia; Boyd, Andrea; Dinkelaker, Aline; Dissertori, Markus; Fasching, David; Fischer, Monika; Föger, Daniel; Foresta, Luca; Fritsch, Lukas; Fuchs, Harald; Gautsch, Christoph; Gerard, Stephan; Goetzloff, Linda; Gołebiowska, Izabella; Gorur, Paavan; Groemer, Gerhard; Groll, Petra; Haider, Christian; Haider, Olivia; Hauth, Eva; Hauth, Stefan; Hettrich, Sebastian; Jais, Wolfgang; Jones, Natalie; Taj-Eddine, Kamal; Karl, Alexander; Kauerhoff, Tilo; Khan, Muhammad Shadab; Kjeldsen, Andreas; Klauck, Jan; Losiak, Anna; Luger, Markus; Luger, Thomas; Luger, Ulrich; McArthur, Jane; Moser, Linda; Neuner, Julia; Orgel, Csilla; Ori, Gian Gabriele; Paternesi, Roberta; Peschier, Jarno; Pfeil, Isabella; Prock, Silvia; Radinger, Josef; Ramirez, Barbara; Ramo, Wissam; Rampey, Mike; Sams, Arnold; Sams, Elisabeth; Sandu, Oana; Sans, Alejandra; Sansone, Petra; Scheer, Daniela; Schildhammer, Daniel; Scornet, Quentin; Sejkora, Nina; Stadler, Andrea; Stummer, Florian; Taraba, Michael; Tlustos, Reinhard; Toferer, Ernst; Turetschek, Thomas; Winter, Egon; Zanella-Kux, Katja

2014-05-01

We report on the MARS2013 mission, a 4-week Mars analog field test in the northern Sahara. Nineteen experiments were conducted by a field crew in Morocco under simulated martian surface exploration conditions, supervised by a Mission Support Center in Innsbruck, Austria. A Remote Science Support team analyzed field data in near real time, providing planning input for the management of a complex system of field assets; two advanced space suit simulators, four robotic vehicles, an emergency shelter, and a stationary sensor platform in a realistic work flow were coordinated by a Flight Control Team. A dedicated flight planning group, external control centers for rover tele-operations, and a biomedical monitoring team supported the field operations. A 10 min satellite communication delay and other limitations pertinent to human planetary surface activities were introduced. The fields of research for the experiments were geology, human factors, astrobiology, robotics, tele-science, exploration, and operations research. This paper provides an overview of the geological context and environmental conditions of the test site and the mission architecture, in particular the communication infrastructure emulating the signal travel time between Earth and Mars. We report on the operational work flows and the experiments conducted, including a deployable shelter prototype for multiple-day extravehicular activities and contingency situations.

Wind turbine blades: A study of prototypes in a steady regime - Unsteady considerations

NASA Astrophysics Data System (ADS)

Leblanc, R.; Goethals, R.; de Saint Louvent, B.

1981-11-01

The results of comparisons of numerical models with experimental results for the performance of prototype wind turbines in steady flows are presented, along with preliminary results on behavior in unsteady flows. The numerical models are based on previous schemes devised for propellers, with modifications for small perturbations, significant radial velocity effects from the wake, and the fact that the speed is induced. Two computational methods are currently used, one a method of short blades, the other the Prandtl lifting line theory. Trials have been run in the T4 wind tunnel using a 3 m horizontal axis machine and a 2.5 m Darrieus. Attention is given to modeling the structural dynamics and turbulent flow structures encountered by wind turbines. Experimental results relating windspeed, angle of attack, and output are presented. Optimization studies have indicated that wind farms will require a 6-7 blade diameter unit spacing to maintain satisfactory group output efficiencies.

Precision Departure Release Capability (PDRC) Final Report

NASA Technical Reports Server (NTRS)

Engelland, Shawn A.; Capps, Richard; Day, Kevin Brian; Kistler, Matthew Stephen; Gaither, Frank; Juro, Greg

2013-01-01

After takeoff, aircraft must merge into en route (Center) airspace traffic flows that may be subject to constraints that create localized demand/capacity imbalances. When demand exceeds capacity, Traffic Management Coordinators (TMCs) and Frontline Managers (FLMs) often use tactical departure scheduling to manage the flow of departures into the constrained Center traffic flow. Tactical departure scheduling usually involves a Call for Release (CFR) procedure wherein the Tower must call the Center to coordinate a release time prior to allowing the flight to depart. In present-day operations release times are computed by the Center Traffic Management Advisor (TMA) decision support tool, based upon manual estimates of aircraft ready time verbally communicated from the Tower to the Center. The TMA-computed release time is verbally communicated from the Center back to the Tower where it is relayed to the Local controller as a release window that is typically three minutes wide. The Local controller will manage the departure to meet the coordinated release time window. Manual ready time prediction and verbal release time coordination are labor intensive and prone to inaccuracy. Also, use of release time windows adds uncertainty to the tactical departure process. Analysis of more than one million flights from January 2011 indicates that a significant number of tactically scheduled aircraft missed their en route slot due to ready time prediction uncertainty. Uncertainty in ready time estimates may result in missed opportunities to merge into constrained en route flows and lead to lost throughput. Next Generation Air Transportation System plans call for development of Tower automation systems capable of computing surface trajectory-based ready time estimates. NASA has developed the Precision Departure Release Capability (PDRC) concept that improves tactical departure scheduling by automatically communicating surface trajectory-based ready time predictions and departure runway assignments to the Center scheduling tool. The PDRC concept also incorporates earlier NASA and FAA research into automation-assisted CFR coordination. The PDRC concept reduces uncertainty by automatically communicating coordinated release times with seconds-level precision enabling TMCs and FLMs to work with target times rather than windows. NASA has developed a PDRC prototype system that integrates the Center's TMA system with a research prototype Tower decision support tool. A two-phase field evaluation was conducted at NASA's North Texas Research Station in Dallas/Fort Worth. The field evaluation validated the PDRC concept and demonstrated reduced release time uncertainty while being used for tactical departure scheduling of more than 230 operational flights over 29 weeks of operations. This paper presents research results from the PDRC research activity. Companion papers present the Concept of Operations and a Technology Description.

Precision Departure Release Capability (PDRC) Technology Description

NASA Technical Reports Server (NTRS)

Engelland, Shawn A.; Capps, Richard; Day, Kevin; Robinson, Corissia; Null, Jody R.

2013-01-01

After takeoff, aircraft must merge into en route (Center) airspace traffic flows which may be subject to constraints that create localized demand-capacity imbalances. When demand exceeds capacity, Traffic Management Coordinators (TMCs) often use tactical departure scheduling to manage the flow of departures into the constrained Center traffic flow. Tactical departure scheduling usually involves use of a Call for Release (CFR) procedure wherein the Tower must call the Center TMC to coordinate a release time prior to allowing the flight to depart. In present-day operations release times are computed by the Center Traffic Management Advisor (TMA) decision support tool based upon manual estimates of aircraft ready time verbally communicated from the Tower to the Center. The TMA-computed release is verbally communicated from the Center back to the Tower where it is relayed to the Local controller as a release window that is typically three minutes wide. The Local controller will manage the departure to meet the coordinated release time window. Manual ready time prediction and verbal release time coordination are labor intensive and prone to inaccuracy. Also, use of release time windows adds uncertainty to the tactical departure process. Analysis of more than one million flights from January 2011 indicates that a significant number of tactically scheduled aircraft missed their en route slot due to ready time prediction uncertainty. Uncertainty in ready time estimates may result in missed opportunities to merge into constrained en route flows and lead to lost throughput. Next Generation Air Transportation System (NextGen) plans call for development of Tower automation systems capable of computing surface trajectory-based ready time estimates. NASA has developed the Precision Departure Release Capability (PDRC) concept that uses this technology to improve tactical departure scheduling by automatically communicating surface trajectory-based ready time predictions to the Center scheduling tool. The PDRC concept also incorporates earlier NASA and FAA research into automation-assisted CFR coordination. The PDRC concept helps reduce uncertainty by automatically communicating coordinated release times with seconds-level precision enabling TMCs to work with target times rather than windows. NASA has developed a PDRC prototype system that integrates the Center's TMA system with a research prototype Tower decision support tool. A two-phase field evaluation was conducted at NASA's North Texas Research Station (NTX) in Dallas-Fort Worth. The field evaluation validated the PDRC concept and demonstrated reduced release time uncertainty while being used for tactical departure scheduling of more than 230 operational flights over 29 weeks of operations. This paper presents the Technology Description. Companion papers include the Final Report and a Concept of Operations.

Precision Departure Release Capability (PDRC): NASA to FAA Research Transition

NASA Technical Reports Server (NTRS)

Engelland, Shawn; Davis, Thomas J.

2013-01-01

After takeoff, aircraft must merge into en route (Center) airspace traffic flows which may be subject to constraints that create localized demand-capacity imbalances. When demand exceeds capacity, Traffic Management Coordinators (TMCs) and Frontline Managers (FLMs) often use tactical departure scheduling to manage the flow of departures into the constrained Center traffic flow. Tactical departure scheduling usually involves use of a Call for Release (CFR) procedure wherein the Tower must call the Center to coordinate a release time prior to allowing the flight to depart. In present-day operations release times are computed by the Center Traffic Management Advisor (TMA) decision support tool based upon manual estimates of aircraft ready time verbally communicated from the Tower to the Center. The TMA-computed release time is verbally communicated from the Center back to the Tower where it is relayed to the Local controller as a release window that is typically three minutes wide. The Local controller will manage the departure to meet the coordinated release time window. Manual ready time prediction and verbal release time coordination are labor intensive and prone to inaccuracy. Also, use of release time windows adds uncertainty to the tactical departure process. Analysis of more than one million flights from January 2011 indicates that a significant number of tactically scheduled aircraft missed their en route slot due to ready time prediction uncertainty. Uncertainty in ready time estimates may result in missed opportunities to merge into constrained en route flows and lead to lost throughput. Next Generation Air Transportation System plans call for development of Tower automation systems capable of computing surface trajectory-based ready time estimates. NASA has developed the Precision Departure Release Capability (PDRC) concept that improves tactical departure scheduling by automatically communicating surface trajectory-based ready time predictions and departure runway assignments to the Center scheduling tool. The PDRC concept also incorporates earlier NASA and FAA research into automation-assisted CFR coordination. The PDRC concept reduces uncertainty by automatically communicating coordinated release times with seconds-level precision enabling TMCs and FLMs to work with target times rather than windows. NASA has developed a PDRC prototype system that integrates the Center's TMA system with a research prototype Tower decision support tool. A two-phase field evaluation was conducted at NASA's North Texas Research Station in Dallas-Fort Worth. The field evaluation validated the PDRC concept and demonstrated reduced release time uncertainty while being used for tactical departure scheduling of more than 230 operational flights over 29 weeks of operations.

Precision Departure Release Capability (PDRC) Concept of Operations

NASA Technical Reports Server (NTRS)

Engelland, Shawn; Capps, Richard A.; Day, Kevin Brian

2013-01-01

After takeoff, aircraft must merge into en route (Center) airspace traffic flows which may be subject to constraints that create localized demandcapacity imbalances. When demand exceeds capacity Traffic Management Coordinators (TMCs) often use tactical departure scheduling to manage the flow of departures into the constrained Center traffic flow. Tactical departure scheduling usually involves use of a Call for Release (CFR) procedure wherein the Tower must call the Center TMC to coordinate a release time prior to allowing the flight to depart. In present-day operations release times are computed by the Center Traffic Management Advisor (TMA) decision support tool based upon manual estimates of aircraft ready time verbally communicated from the Tower to the Center. The TMA-computed release is verbally communicated from the Center back to the Tower where it is relayed to the Local controller as a release window that is typically three minutes wide. The Local controller will manage the departure to meet the coordinated release time window. Manual ready time prediction and verbal release time coordination are labor intensive and prone to inaccuracy. Also, use of release time windows adds uncertainty to the tactical departure process. Analysis of more than one million flights from January 2011 indicates that a significant number of tactically scheduled aircraft missed their en route slot due to ready time prediction uncertainty. Uncertainty in ready time estimates may result in missed opportunities to merge into constrained en route flows and lead to lost throughput. Next Generation Air Transportation System (NextGen) plans call for development of Tower automation systems capable of computing surface trajectory-based ready time estimates. NASA has developed the Precision Departure Release Capability (PDRC) concept that uses this technology to improve tactical departure scheduling by automatically communicating surface trajectory-based ready time predictions to the Center scheduling tool. The PDRC concept also incorporates earlier NASA and FAA research into automation-assisted CFR coordination. The PDRC concept helps reduce uncertainty by automatically communicating coordinated release times with seconds-level precision enabling TMCs to work with target times rather than windows. NASA has developed a PDRC prototype system that integrates the Center's TMA system with a research prototype Tower decision support tool. A two-phase field evaluation was conducted at NASA's North Texas Research Station (NTX) in DallasFort Worth. The field evaluation validated the PDRC concept and demonstrated reduced release time uncertainty while being used for tactical departure scheduling of more than 230 operational flights over 29 weeks of operations. This paper presents the Concept of Operations. Companion papers include the Final Report and a Technology Description. ? SUBJECT:

Performance of Prototype High-Flow Inhalable Dust Sampler in a Livestock Production Facility

PubMed Central

Anthony, T. Renée; Cai, Changjie; Mehaffy, John; Sleeth, Darrah; Volckens, John

2017-01-01

A high-flow inhalable sampler, designed for operational flow rates up to 10 L/min using computer simulations and examined in wind tunnel experiments, was evaluated in the field. This prototype sampler was deployed in collocation with an IOM (the benchmark standard sampler) in a swine farrowing building to examine the sampling performance for assessing concentrations of inhalable particulate mass and endotoxin. Paired samplers were deployed for 24-hours on 19 days over a three-month period. On each sampling day, the paired samplers were deployed at three fixed locations and data were analyzed to identify agreement and to examine systematic biases between concentrations measured by these samplers. Thirty-six paired gravimetric samples were analyzed; insignificant, unsubstantial differences between concentrations were identified between the two samplers (p=0.16; mean difference 0.03 mg/m3). Forty-four paired samples were available for endotoxin analysis, and a significant (p=0.001) difference in endotoxin concentration was identified: the prototype sampler, on average, had 120 EU/m3 more endotoxin than did the IOM samples. Since the same gravimetric samples were analyzed for endotoxin content, the endotoxin difference is likely attributable to differences in endotoxin extraction. The prototype’s disposable thin-film polycarbonate capsule was included with the filter in the 1-hour extraction procedure while the internal plastic cassette of the IOM required a rinse procedure that is susceptible to dust losses. Endotoxin concentrations measured with standard plastic IOM inserts that follow this rinsing procedure may underestimate the true endotoxin exposure concentrations. The maximum concentrations in the study (1.55 mg/m3 gravimetric, 2328 EU/m3 endotoxin) were lower than other agricultural or industrial environments. Future work should explore the performance of the prototype sampler in dustier environments, where concentrations approach particulates not otherwise specified (PNOS) limits of 10 mg/m3, including using the prototype as a personal sampler. PMID:27792469

A prototype of injector to control and to detect the release of magnetic beads within the constraints of multibifurcation magnetic resonance navigation procedures.

PubMed

Bigot, Alexandre; Soulez, Gilles; Martel, Sylvain

2017-01-01

An injector equipped with a bead capture and a bead detection system is presented. In the context of magnetic resonance navigation (MRN), in which MRI gradients are used to steer intravascular therapeutic carriers, fast and reliable injection is essential. In this paper, we present a prototype of injector to control and to detect the release of magnetic beads. The injector relies on two distinct subsystems: (1) the capture subsystem, which creates local magnetic force to stop the flow of magnetic beads; and (2) the detection subsystem, which detects flowing beads and generates a trigger signal to start MRI gradient pulses. Both systems rely on small microcoils wound on the tubing. Five-turn microcoils show the best compromise between size and performance. Less than 5 mW of power is required to capture 0.8-mm beads moving in a flow above 5 mL min -1 or when a gradient above 200 mT m -1 is applied. The detection system is not sensitive to noise and detects every 0.8-mm bead in flow rates up to 14 mL m -1 . The prototype of injector shows performance above the requirements inherent to magnetic resonance navigation. This system is a step toward in vivo multibifurcation MRN. Magn Reson Med 77:444-452, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Intravascular ultrasound catheter to enhance microbubble-based drug delivery via acoustic radiation force.

PubMed

Kilroy, Joseph P; Klibanov, Alexander L; Wamhoff, Brian R; Hossack, John A

2012-10-01

Previous research has demonstrated that acoustic radiation force enhances intravascular microbubble adhesion to blood vessels in the presence of flow for moleculartargeted ultrasound imaging and drug delivery. A prototype acoustic radiation force intravascular ultrasound (ARFIVUS) catheter was designed and fabricated to displace a microbubble contrast agent in flow representative of conditions encountered in the human carotid artery. The prototype ARFIVUS transducer was designed to match the resonance frequency of 1.4- to 2.6-μm-diameter microbubbles modeled by an experimentally verified 1-D microbubble acoustic radiation force translation model. The transducer element was an elongated Navy Type I (hard) lead zirconate titanate (PZT) ceramic designed to operate at 3 MHz. Fabricated devices operated with center frequencies of 3.3 and 3.6 MHz with -6-dB fractional bandwidths of 55% and 50%, respectively. Microbubble translation velocities as high as 0.86 m/s were measured using a high-speed streak camera when insonating with the ARFIVUS transducer. Finally, the prototype was used to displace microbubbles in a flow phantom while imaging with a commercial 45-MHz imaging IVUS transducer. A sustained increase of 31 dB in average video intensity was measured following insonation with the ARFIVUS, indicating microbubble accumulation resulting from the application of acoustic radiation force.

Laminar Flow Supersonic Wind Tunnel primary air injector

NASA Technical Reports Server (NTRS)

Smith, Brooke Edward

1993-01-01

This paper describes the requirements, design, and prototype testing of the flex-section and hinge seals for the Laminar Flow Supersonic Wind Tunnel Primary Injector. The supersonic atmospheric primary injector operates between Mach 1.8 and Mach 2.2 with mass-flow rates of 62 to 128 lbm/s providing the necessary pressure reduction to operate the tunnel in the desired Reynolds number (Re) range.

Evaluation of a flexible bronchoscope prototype designed for bronchoscopy during mechanical ventilation: a proof-of-concept study.

PubMed

Nay, M-A; Auvet, A; Mankikian, J; Herve, V; Dequin, P-F; Guillon, A

2017-06-01

Bronchoscopy during mechanical ventilation of patients' lungs significantly affects ventilation because of partial obstruction of the tracheal tube, and may thus be omitted in the most severely ill patients. It has not previously been possible to reduce the external diameter of the bronchoscope without reducing the diameter of the suction channel, thus reducing the suctioning capacity of the device. We believed that a better-designed bronchoscope could improve the safety of bronchoscopy in patients whose lungs were ventilated. We designed a flexible bronchoscope prototype with a drumstick-shaped head consisting of a long, thin proximal portion; a short and large distal portion for camera docking; and a large suction channel throughout the length of the device. The aims of our study were to test the impact of our prototype on mechanical ventilation when inserted into the tracheal tube, and to assess suctioning capacity. We first tested the efficiency of the suction channel, and demonstrated that the suction flow of the prototype was similar to that of conventional adult bronchoscopes. We next evaluated the consequences of bronchoscopy when using the prototype on minute ventilation and intrathoracic pressures during mechanical ventilation: firstly, in vitro using a breathing simulator; and secondly, in vivo using a porcine model of pulmonary ventilation. The insertion of adult bronchoscopes into the tracheal tube immediately impaired the protective ventilation strategy employed, whereas the prototype preserved it. For the first time, we have developed an innovative flexible bronchoscope designed for bronchoscopy during invasive mechanical ventilation, that both preserved the protective ventilation strategy, and enabled efficient suction flow. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

Testing Planetary Volcanism Models with Multi-Wavelength Near Infrared Observations of Kilauea Flows and Fountains

NASA Astrophysics Data System (ADS)

Howell, Robert R.; Radebaugh, Jani; M. C Lopes, Rosaly; Kerber, Laura; Solomonidou, Anezina; Watkins, Bryn

2017-10-01

Using remote sensing of planetary volcanism on objects such as Io to determine eruption conditions is challenging because the emitting region is typically not resolved and because exposed lava cools so quickly. A model of the cooling rate and eruption mechanism is typically used to predict the amount of surface area at different temperatures, then that areal distribution is convolved with a Planck blackbody emission curve, and the predicted spectra is compared with observation. Often the broad nature of the Planck curve makes interpretation non-unique. However different eruption mechanisms (for example cooling fire fountain droplets vs. cooling flows) have very different area vs. temperature distributions which can often be characterized by simple power laws. Furthermore different composition magmas have significantly different upper limit cutoff temperatures. In order to test these models in August 2016 and May 2017 we obtained spatially resolved observations of spreading Kilauea pahoehoe flows and fire fountains using a three-wavelength near-infrared prototype camera system. We have measured the area vs. temperature distribution for the flows and find that over a relatively broad temperature range the distribution does follow a power law matching the theoretical predictions. As one approaches the solidus temperature the observed area drops below the simple model predictions by an amount that seems to vary inversely with the vigor of the spreading rate. At these highest temperatures the simple models are probably inadequate. It appears necessary to model the visco-elastic stretching of the very thin crust which covers even the most recently formed surfaces. That deviation between observations and the simple models may be particularly important when using such remote sensing observations to determine magma eruption temperatures.

Virtual world reconstruction using the modeling and simulation extended vector product prototype

DOT National Transportation Integrated Search

1997-05-30

The MS Extended Vector Product (MSEVP) prototype being developed is an extended vector product format-based product containing a continuous surface representation and a consistent view of elevation across the thematic coverages contained within a dat...

Cytometer on a Chip

NASA Technical Reports Server (NTRS)

Fernandez, Salvador M.

2011-01-01

A cytometer now under development exploits spatial sorting of sampled cells on a microarray chip followed by use of grating-coupled surface-plasmon-resonance imaging (GCSPRI) to detect the sorted cells. This cytometer on a chip is a prototype of contemplated future miniature cytometers that would be suitable for rapidly identifying pathogens and other cells of interest in both field and laboratory applications and that would be attractive as alternatives to conventional flow cytometers. The basic principle of operation of a conventional flow cytometer requires fluorescent labeling of sampled cells, stringent optical alignment of a laser beam with a narrow orifice, and flow of the cells through the orifice, which is subject to clogging. In contrast, the principle of operation of the present cytometer on a chip does not require fluorescent labeling of cells, stringent optical alignment, or flow through a narrow orifice. The basic principle of operation of the cytometer on a chip also reduces the complexity, mass, and power of the associated laser and detection systems, relative to those needed in conventional flow cytometry. Instead of making cells flow in single file through a narrow flow orifice for sequential interrogation as in conventional flow cytometry, a liquid containing suspended sampled cells is made to flow over the front surface of a microarray chip on which there are many capture spots. Each capture spot is coated with a thin (approximately 50-nm) layer of gold that is, in turn, coated with antibodies that bind to cell-surface molecules characteristic of one the cell species of interest. The multiplicity of capture spots makes it possible to perform rapid, massively parallel analysis of a large cell population. The binding of cells to each capture spot gives rise to a minute change in the index of refraction at the surface of the chip. This change in the index of refraction is what is sensed in GCSPRI, as described briefly below. The identities of the various species in a sample of cells is spatially encoded in the chip by the pattern of capture spots. The number of cells of a particular species is determined from the magnitude of the GCSPRI signal from that spot. GCSPRI as used here can be summarized as follows: The cytometer chip is fabricated with a diffraction grating on its front surface. The chip is illuminated with a light emitting diode (LED) from the front. By proper choice of grating parameters and of the wavelength and the angle of incidence of a laser beam, laser light can be made to be coupled into an electromagnetic mode that resonates with surface plasmons and thus couples light into surface plasmons. Coupling of light into a surface plasmon at a given location reduces the amount of incident light reflected from that location. A change in the index of refraction at the surface of a capture spot gives rise to a change in the resonance condition. Depending on the specific design, the change in the index of refraction could manifest itself as a brightening or darkening, a change in the wavelength needed to excite the plasmon at a given angle of incidence, or a change in the angle of incidence needed to excite the plasmon at a given wavelength. Whereas a multiwavelength laser system with multichannel detection would be needed to detect multiple species in conventional flow cytometry, it suffices to use an LED and a single detector channel in the GCSPRI approach: this contributes significantly to reductions in cost, complexity, size, mass, and power. GCSPRI cytometer chips could be made of plastic and could be mass-produced cheaply by use of molding and other methods adopted from the manufacture of digital video disks. These methods are amenable to a high degree of miniaturization: such additional features as fluidic channels, reaction chambers, and fluid-coupling ports could readily be incorporated into the chips, without incurring substantial additional costs.

Cytometer on a Chip

NASA Technical Reports Server (NTRS)

Fernandez, Salvador M.

2011-01-01

A cytometer now under development exploits spatial sorting of sampled cells on a microarray chip followed by use of grating-coupled surface-plasmon-resonance imaging (GCSPRI) to detect the sorted cells. This cytometer on a chip is a prototype of contemplated future miniature cytometers that would be suitable for rapidly identifying pathogens and other cells of interest in both field and laboratory applications and that would be attractive as alternatives to conventional flow cytometers. The basic principle of operation of a conventional flow cytometer requires fluorescent labeling of sampled cells, stringent optical alignment of a laser beam with a narrow orifice, and flow of the cells through the orifice, which is subject to clogging. In contrast, the principle of operation of the present cytometer on a chip does not require fluorescent labeling of cells, stringent optical alignment, or flow through a narrow orifice. The basic principle of operation of the cytometer on a chip also reduces the complexity, mass, and power of the associated laser and detection systems, relative to those needed in conventional flow cytometry. Instead of making cells flow in single file through a narrow flow orifice for sequential interrogation as in conventional flow cytometry, a liquid containing suspended sampled cells is made to flow over the front surface of a microarray chip on which there are many capture spots. Each capture spot is coated with a thin (.50-nm) layer of gold that is, in turn, coated with antibodies that bind to cell-surface molecules characteristic of the cell species of interest. The multiplicity of capture spots makes it possible to perform rapid, massively parallel analysis of a large cell population. The binding of cells to each capture spot gives rise to a minute change in the index of refraction at the surface of the chip. This change in the index of refraction is what is sensed in GCSPRI, as described briefly below. The identities of the various species in a sample of cells is spatially encoded in the chip by the pattern of capture spots. The number of cells of a particular species is determined from the magnitude of the GCSPRI signal from that spot. GCSPRI as used here can be summarized as follows: The cytometer chip is fabricated with a diffraction grating on its front surface. The chip is illuminated with a light emitting diode (LED) from the front. By proper choice of grating parameters and of the wavelength and the angle of incidence of a laser beam, laser light can be made to be coupled into an electromagnetic mode that resonates with surface plasmons and thus couples light into surface plasmons. Coupling of light into a surface plasmon at a given location reduces the amount of incident light reflected from that location. A change in the index of refraction at the surface of a capture spot gives rise to a change in the resonance condition. Depending on the specific design, the change in the index of refraction could manifest itself as a brightening or darkening, a change in the wavelength needed to excite the plasmon at a given angle of incidence, or a change in the angle of incidence needed to excite the plasmon at a given wavelength. Whereas a multiwavelength laser system with multichannel detection would be needed to detect multiple species in conventional flow cytometry, it suffices to use an LED and a single detector channel in the GCSPRI approach: this contributes significantly to reductions in cost, complexity, size, mass, and power. GCSPRI cytometer chips could be made of plastic and could be mass-produced cheaply by use of molding and other methods adopted from the manufacture of digital video disks. These methods are amenable to a high degree of miniaturization: such additional features as fluidic channels, reaction chambers, and fluid-coupling ports could readily be incorporated into the chips, without incurring substantial additional costs.

Magnetic shielding of large high-power-satellite solar arrays using internal currents

NASA Technical Reports Server (NTRS)

Parker, L. W.; Oran, W. A.

1979-01-01

Present concepts for solar power satellites involve dimensions up to tens of kilometers and operating internal currents up to hundreds of kiloamperes. A question addressed is whether the local magnetic fields generated by these strong currents during normal operation can shield the array against impacts by plasma ions and electrons (and from thruster plasmas) which can cause possible losses such as power leakage and surface erosion. One of several prototype concepts was modeled by a long narrow rectangular panel 2 km wide and 20 km long. The currents flow in a parallel across the narrow dimension (sheet current) and along the edge (wire currents). The wire currents accumulate from zero to 100 kiloamp and are the dominant sources. The magnetic field is approximated analytically. The equations of motion for charged particles in this magnetic field are analyzed. The ion and electron fluxes at points on the surface are represented analytically for monoenergetic distributions and are evaluated.

Effect of process parameters on formability of laser melting deposited 12CrNi2 alloy steel

NASA Astrophysics Data System (ADS)

Peng, Qian; Dong, Shiyun; Kang, Xueliang; Yan, Shixing; Men, Ping

2018-03-01

As a new rapid prototyping technology, the laser melting deposition technology not only has the advantages of fast forming, high efficiency, but also free control in the design and production chain. Therefore, it has drawn extensive attention from community.With the continuous improvement of steel performance requirements, high performance low-carbon alloy steel is gradually integrated into high-tech fields such as aerospace, high-speed train and armored equipment.However, it is necessary to further explore and optimize the difficult process of laser melting deposited alloy steel parts to achieve the performance and shape control.This article took the orthogonal experiment on alloy steel powder by laser melting deposition ,and revealed the influence rule of the laser power, scanning speed, powder gas flow on the quality of the sample than the dilution rate, surface morphology and microstructure analysis were carried out.Finally, under the optimum technological parameters, the Excellent surface quality of the alloy steel forming part with high density, no pore and cracks was obtained.

Integrating Clarus data in traffic signal system operation : a survivable real-time weather-responsive system.

DOT National Transportation Integrated Search

2011-07-11

This report presents a prototype of a secure, dependable, real-time weather-responsive traffic signal system. The prototype executes two tasks: 1) accesses weather information that provides near real-time atmospheric and pavement surface condition ob...

Acoustical and noise redesign considerations when trying to increase patient privacy while ensuring comfort

NASA Astrophysics Data System (ADS)

Klavetter, Eric

2005-09-01

An internal assessment was undertaken to understand the flow of patients to ensure comfort and privacy during their health care experience at Mayo Clinic. A number of different prototypes, work flows, and methodologies were utilized and assessed to determine the ``best experience for our patients.'' A number of prototypes ranging from self-check in to personal pagers were assessed along with creating environments that introduced ``passive distractions'' for acoustical and noise management, which can range from fireplaces, to coffee shops to playgrounds to ``tech corridors.'' While a number of these designs are currently being piloted, the over-reaching goal is to make the patient experience ``like no other'' when receiving their care at Mayo Clinic.

Development of Doppler Global Velocimetry as a Flow Diagnostics Tool

NASA Technical Reports Server (NTRS)

Meyers, James F.

1995-01-01

The development of Doppler global velocimetry is described from its inception to its use as a flow diagnostics tool. Its evolution is traced from an elementary one-component laboratory prototype, to a full three-component configuration operating in a wind tunnel at focal distances exceeding 15 m. As part of the developmental process, several wind tunnel flow field investigations were conducted. These included supersonic flow measurements about an oblique shock, subsonic and supersonic measurements of the vortex flow above a delta wing, and three-component measurements of a high-speed jet.

Vibrotactile Compliance Feedback for Tangential Force Interaction.

PubMed

Heo, Seongkook; Lee, Geehyuk

2017-01-01

This paper presents a method to generate a haptic illusion of compliance using a vibrotactile actuator when a tangential force is applied to a rigid surface. The novel method builds on a conceptual compliance model where a physical object moves on a textured surface in response to a tangential force. The method plays vibration patterns simulating friction-induced vibrations as an applied tangential force changes. We built a prototype consisting of a two-dimensional tangential force sensor and a surface transducer to test the effectiveness of the model. Participants in user experiments with the prototype perceived the rigid surface of the prototype as a moving, rubber-like plate. The main findings of the experiments are: 1) the perceived stiffness of a simulated material can be controlled by controlling the force-playback transfer function, 2) its perceptual properties such as softness and pleasantness can be controlled by changing friction grain parameters, and 3) the use of the vibrotactile compliance feedback reduces participants' workload including physical demand and frustration while performing a force repetition task.

Fiber-Optic/Photoelastic Flow Sensors

NASA Technical Reports Server (NTRS)

Wesson, Laurence N.; Cabato, Nellie L.; Brooks, Edward F.

1995-01-01

Simple, rugged, lightweight transducers detect periodic vortices. Fiber-optic-coupled transducers developed to measure flows over wide dynamic ranges and over wide temperature ranges in severe environments. Used to measure flows of fuel in advanced aircraft engines. Feasibility of sensors demonstrated in tests of prototype sensor in water flowing at various temperatures and speeds. Particularly attractive for aircraft applications because optical fibers compact and make possible transmission of sensor signals at high rates with immunity from electromagnetic interference at suboptical frequencies. Sensors utilize optical-to-optical conversion via photoelastic effect.

Implementing a prototyping network for injection moulded imaging lenses in Finland

NASA Astrophysics Data System (ADS)

Keränen, K.; Mäkinen, J.-T.; Pääkkönen, E. J.; Koponen, M.; Karttunen, M.; Hiltunen, J.; Karioja, P.

2005-10-01

A network for prototyping imaging lenses using injection moulding was established in Finland. The network consists of several academic and industrial partners capable of designing, processing and characterising imaging lenses produced by injection moulding technology. In order to validate the operation of the network a demonstrator lens was produced. The process steps included in the manufacturing were lens specification, designing and modelling, material selection, mould tooling, moulding process simulation, injection moulding and characterisation. A magnifying imaging singlet lens to be used as an add-on in a camera phone was selected as a demonstrator. The design of the add-on lens proved to be somewhat challenging, but a double aspheric singlet lens design fulfilling nearly the requirement specification was produced. In the material selection task the overall characteristics profile of polymethyl methacrylate (PMMA) material was seen to be the most fitting to the pilot case. It is a low cost material with good moulding properties and therefore it was selected as a material for the pilot lens. Lens mould design was performed using I-DEAS and tested by using MoldFlow 3D injection moulding simulation software. The simulations predicted the achievable lens quality in the processing, when using a two-cavity mould design. First cavity was tooled directly into the mould plate and the second cavity was made by tooling separate insert pieces for the mould. Mould material was steel and the inserts were made from Moldmax copper alloy. Parts were tooled with high speed milling machines. Insert pieces were hand polished after tooling. Prototype lenses were injection moulded using two PMMA grades, namely 6N and 7N. Different process parameters were also experimented in the injection moulding test runs. Prototypes were characterised by measuring mechanical dimensions, surface profile, roughness and MTF of the lenses. Characterisations showed that the lens surface RMS roughness was 30-50 nm and the profile deviation was 5 μm from the design at a distance of 0.3 mm from the lens vertex. These manufacturing defects caused that the measured MTF values were lower than designed. The lens overall quality, however, was adequate to demonstrate the concept successfully. Through the implementation of the demonstrator lens we could test effectively different stages of the manufacturing process and get information about process component weight and risk factors and validate the overall performance of the network.

Results from a scaled reactor cavity cooling system with water at steady state

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lisowski, D. D.; Albiston, S. M.; Tokuhiro, A.

We present a summary of steady-state experiments performed with a scaled, water-cooled Reactor Cavity Cooling System (RCCS) at the Univ. of Wisconsin - Madison. The RCCS concept is used for passive decay heat removal in the Next Generation Nuclear Plant (NGNP) design and was based on open literature of the GA-MHTGR, HTR-10 and AVR reactor. The RCCS is a 1/4 scale model of the full scale prototype system, with a 7.6 m structure housing, a 5 m tall test section, and 1,200 liter water storage tank. Radiant heaters impose a heat flux onto a three riser tube test section, representingmore » a 5 deg. radial sector of the actual 360 deg. RCCS design. The maximum heat flux and power levels are 25 kW/m{sup 2} and 42.5 kW, and can be configured for variable, axial, or radial power profiles to simulate prototypic conditions. Experimental results yielded measurements of local surface temperatures, internal water temperatures, volumetric flow rates, and pressure drop along the test section and into the water storage tank. The majority of the tests achieved a steady state condition while remaining single-phase. A selected number of experiments were allowed to reach saturation and subsequently two-phase flow. RELAP5 simulations with the experimental data have been refined during test facility development and separate effects validation of the experimental facility. This test series represents the completion of our steady-state testing, with future experiments investigating normal and off-normal accident scenarios with two-phase flow effects. The ultimate goal of the project is to combine experimental data from UW - Madison, UI, ANL, and Texas A and M, with system model simulations to ascertain the feasibility of the RCCS as a successful long-term heat removal system during accident scenarios for the NGNP. (authors)« less

Software Testing for Evolutionary Iterative Rapid Prototyping

DTIC Science & Technology

1990-12-01

kept later hours than I did. Amidst the hustle and bustle, their prayers and help around the house were a great ast.. Finally, if anything shows the...possible meanings. A basic dictionary definition describes prototyping as "an original type , form, or instance that serves as a modfe] on which later...on program size. Asset instruments 49 the subject procedure and produces a graph of the structure for the type of data flow testing conducted. It

Illuminance and luminance distributions of a prototype ambient illumination system for Space Station Freedom

NASA Technical Reports Server (NTRS)

Mullican, R. C.; Hayes, B. C.

1991-01-01

Preliminary results of research conducted in the late 1970's indicate that perceptual qualities of an enclosure can be influenced by the distribution of illumination within the enclosure. Subjective impressions such as spaciousness, perceptual clarity, and relaxation or tenseness, among others, appear to be related to different combinations of surface luminance. A prototype indirect ambient illumination system was developed which will allow crew members to alter surface luminance distributions within an enclosed module, thus modifying perceptual cues to match crew preferences. A traditional lensed direct lighting system was compared to the prototype utilizing the full-scale mockup of Space Station Freedom developed by Marshall Space Flight Center. The direct lensed system was installed in the habitation module with the indirect prototype deployed in the U.S. laboratory module. Analysis centered on the illuminance and luminance distributions resultant from these systems and the implications of various luminaire spacing options. All test configurations were evaluated for compliance with NASA Standard 3000, Man-System Integration Standards.

Simultaneous PET/MR imaging of the brain: feasibility of cerebral blood flow measurements with FAIR-TrueFISP arterial spin labeling MRI.

PubMed

Stegger, Lars; Martirosian, Petros; Schwenzer, Nina; Bisdas, Sotirios; Kolb, Armin; Pfannenberg, Christina; Claussen, Claus D; Pichler, Bernd; Schick, Fritz; Boss, Andreas

2012-11-01

Hybrid positron emission tomography/magnetic resonance imaging (PET/MRI) with simultaneous data acquisition promises a comprehensive evaluation of cerebral pathophysiology on a molecular, anatomical, and functional level. Considering the necessary changes to the MR scanner design the feasibility of arterial spin labeling (ASL) is unclear. To evaluate whether cerebral blood flow imaging with ASL is feasible using a prototype PET/MRI device. ASL imaging of the brain with Flow-sensitive Alternating Inversion Recovery (FAIR) spin preparation and true fast imaging in steady precession (TrueFISP) data readout was performed in eight healthy volunteers sequentially on a prototype PET/MRI and a stand-alone MR scanner with 128 × 128 and 192 × 192 matrix sizes. Cerebral blood flow values for gray matter, signal-to-noise and contrast-to-noise ratios, and relative signal change were compared. Additionally, the feasibility of ASL as part of a clinical hybrid PET/MRI protocol was demonstrated in five patients with intracerebral tumors. Blood flow maps showed good delineation of gray and white matter with no discernible artifacts. The mean blood flow values of the eight volunteers on the PET/MR system were 51 ± 9 and 51 ± 7 mL/100 g/min for the 128 × 128 and 192 × 192 matrices (stand-alone MR, 57 ± 2 and 55 ± 5, not significant). The value for signal-to-noise (SNR) was significantly higher for the PET/MRI system using the 192 × 192 matrix size (P < 0.01), the relative signal change (δS) was significantly lower for the 192 × 192 matrix size (P = 0.02). ASL imaging as part of a clinical hybrid PET/MRI protocol could successfully be accomplished in all patients in diagnostic image quality. ASL brain imaging is feasible with a prototype hybrid PET/MRI scanner, thus adding to the value of this novel imaging technique.

The development of a cryogenic over-pressure pump

NASA Astrophysics Data System (ADS)

Alvarez, M.; Cease, H.; Flaugher, B.; Flores, R.; Garcia, J.; Lathrop, A.; Ruiz, F.

2014-01-01

A cryogenic over-pressure pump (OPP) was tested in the prototype telescope liquid nitrogen (LN2) cooling system for the Dark Energy Survey (DES) Project. This OPP consists of a process cylinder (PC), gas generator, and solenoid operated valves (SOVs). It is a positive displacement pump that provided intermittent liquid nitrogen (LN2) flow to an array of charge couple devices (CCDs) for the prototype Dark Energy Camera (DECam). In theory, a heater submerged in liquid would generate the drive gas in a closed loop cooling system. The drive gas would be injected into the PC to displace that liquid volume. However, due to limitations of the prototype closed loop nitrogen system (CCD cooling system) for DECam, a quasiclosed-loop nitrogen system was created. During the test of the OPP, the CCD array was cooled to its designed set point temperature of 173K. It was maintained at that temperature via electrical heaters. The performance of the OPP was captured in pressure, temperature, and flow rate in the CCD LN2 cooling system at Fermi National Accelerator Laboratory (FNAL).

Material characterization for morphing purposes in order to match flight requirements

NASA Astrophysics Data System (ADS)

Geier, Sebastian; Kintscher, Markus; Heintze, Olaf; Wierach, Peter; Monner, Hans-Peter; Wiedemann, Martin

2012-04-01

Natural laminar flow is one of the challenging aims of the current aerospace research. Main reasons for the aerodynamic transition from laminar into turbulent flow focusing on the airfoil-structure is the aerodynamic shape and the surface roughness. The Institute of Composite Structures and Adaptive Systems at the German Aerospace Center in Braunschweig works on the optimization of the aerodynamic-loaded structure of future aircrafts in order to increase their efficiency. Providing wing structures suited for natural laminar flow is a step towards this goal. Regarding natural laminar flow, the structural design of the leading edge of a wing is of special interest. An approach for a gap-less leading edge was developed to provide a gap- and step-less high quality surface suited for natural laminar flow and to reduce slat noise. In a national project the first generation of the 3D full scale demonstrator was successfully tested in 2010. The prototype consists of several new technologies, opening up the issue of matching the long and challenging list of airworthiness requirements simultaneously. Therefore the developed composite structure was intensively tested for further modifications according to meet requirements for abrasion, impact and deicing basically. The former presented structure consists completely of glass-fiber-prepreg (GFRP-prepreg). New functions required the addition of a new material-mix, which has to fit into the manufacturing-chain of the composite structure. In addition the hybrid composites have to withstand high loadings, high bending-induced strains (1%) and environmentally influenced aging. Moreover hot-wet cycling tests are carried out for the basic GFRP-structure in order to simulate the long term behavior of the material under extrem conditions. The presented paper shows results of four-points-bending-tests of the most critical section of the morphing leading edge device. Different composite-hybrids are built up and processed. An experimental based trend towards an optimized material design will be shown.

Heat transfer characteristics of a surface type direct contact boiler

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deeds, R.S.; Jacobs, H.R.; Boehm, R.F.

1976-03-01

Two direct contact heat exchangers were constructed and test results were obtained using water and refrigerant 113 as the working fluids. The heat exchangers were operated in a three-phase mode; the water remained liquid throughout the vessel and the liquid refrigerant 113 underwent vaporization following direct injection into the water. The effect of important operational parameters--operating heights, refrigerant 113 injection techniques, mass flow ratios, and temperatures--was studied to determine generalized trends important in the design and operation of a prototype three-phase direct contact heat exchanger. The primary system used in this study performed well overall. The initial favorable results ofmore » this study warrant further investigation of direct contact heat exchange as a means of utilizing geothermal energy.« less

A fast and flexible method for manufacturing 3D molded interconnect devices by the use of a rapid prototyping technology

NASA Astrophysics Data System (ADS)

Amend, P.; Pscherer, C.; Rechtenwald, T.; Frick, T.; Schmidt, M.

This paper presents experimental results of manufacturing MID-prototypes by means of SLS, laser structuring and metallization. Therefore common SLS powder (PA12) doped with laser structuring additives is used. First of all the influence of the additives on the characteristic temperatures of melting and crystallization is analyzed by means of DSC. Afterwards the sintering process is carried out and optimized by experiments. Finally the generated components are qualified regarding their density, mechanical properties and surface roughness. Especially the surface quality is important for the metallization process. Therefore surface finishing techniques are investigated.

High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turnquist, Norman; Qi, Xuele; Raminosoa, Tsarafidy

2013-12-20

This report summarizes the progress made during the April 01, 2010 – December 30, 2013 period under Cooperative Agreement DE-EE0002752 for the U.S. Department of Energy entitled “High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems.” The overall objective of this program is to advance the technology for well fluids lifting systems to meet the foreseeable pressure, temperature, and longevity needs of the Enhanced Geothermal Systems (EGS) industry for the coming ten years. In this program, lifting system requirements for EGS wells were established via consultation with industry experts and site visits. A number of artificial lift technologies were evaluated with regard tomore » their applicability to EGS applications; it was determined that a system based on electric submersible pump (ESP) technology was best suited to EGS. Technical barriers were identified and a component-level technology development program was undertaken to address each barrier, with the most challenging being the development of a power-dense, small diameter motor that can operate reliably in a 300°C environment for up to three years. Some of the targeted individual component technologies include permanent magnet motor construction, high-temperature insulation, dielectrics, bearings, seals, thrust washers, and pump impellers/diffusers. Advances were also made in thermal management of electric motors. In addition to the overall system design for a full-scale EGS application, a subscale prototype was designed and fabricated. Like the full-scale design, the subscale prototype features a novel “flow-through-the-bore” permanent magnet electric motor that combines the use of high temperature materials with an internal cooling scheme that limits peak internal temperatures to <330°C. While the full-scale high-volume multi-stage pump is designed to lift up to 80 kg/s of process water, the subscale prototype is based on a production design that can pump 20 kg/s and has been modified for high-temperature operation. In parallel with the design and fabrication of the subscale prototype ESP system, a subscale test facility consisting of a high-temperature-high-pressure flow loop was designed, fabricated, and installed at GE Global Research in Niskayuna, NY. A test plan for the prototype system was also established. The original plan of testing the prototype hardware in the flow loop was delayed until a future date.« less

An Evaluation of the Argentinean Basic Trainer Aircraft Domestic Development Project

DTIC Science & Technology

2012-03-01

Prototype, 1st jet built in Latin America 1947 IAe 31 Colibrí Two- seat Trainer aircraft 3 National design 1948 IAe 30 Ñancú Fighter/Attack prototype...37 Supersonic delta-wing interceptor (Glider, unpowered prototype only) 1 Designed by Reimar Horten. 1957 IAe 46 Ranquel 2- seat utility...return all surfaces to neutral. It must be operable from both positions, with priority on the rear command seat . • Ergonomic Throttle controls on the

Skin microvascular flow during hypobaric exposure with and without a mechanical counter-pressure space suit glove

NASA Technical Reports Server (NTRS)

Tanaka, Kunihiko; Waldie, James; Steinbach, Gregory C.; Webb, Paul; Tourbier, Dietmar; Knudsen, Jeffrey; Jarvis, Christine W.; Hargens, Alan R.

2002-01-01

INTRODUCTION: Current space suits are rigid, gas-pressurized shells that protect astronauts from the vacuum of space. A tight elastic garment or mechanical-counter-pressure (MCP) suit generates pressure by compression and may have several advantages over current space suit technology. In this study, we investigated local microcirculatory effects produced with and without a prototype MCP glove. METHODS: The right hand of eight normal volunteers was studied at normal ambient pressure and during exposure to -50, -100 and -150 mm Hg with and without the MCP glove. Measurements included the pressure against the hand, skin microvascular flow, temperature on the dorsum of the hand, and middle finger girth. RESULTS: Without the glove, skin microvascular flow and finger girth significantly increased with negative pressure, and the skin temperature decreased compared with the control condition. The MCP glove generated approximately 200 mm Hg at the skin surface; all measured values remained at control levels during exposure to negative pressure. DISCUSSION: Without the glove, skin microvascular flow and finger girth increased with negative pressure, probably due to a blood shift toward the hand. The elastic compression of the material of the MCP glove generated pressure on the hand similar to that in current gas-pressurized space suit gloves. The MCP glove prevented the apparent blood shift and thus maintained baseline values of the measured variables despite exposure of the hand to negative pressure.

Prototype of an opto-capacitive probe for non-invasive sensing cerebrospinal fluid circulation

NASA Astrophysics Data System (ADS)

Myllylä, Teemu; Vihriälä, Erkki; Pedone, Matteo; Korhonen, Vesa; Surazynski, Lukasz; Wróbel, Maciej; Zienkiewicz, Aleksandra; Hakala, Jaakko; Sorvoja, Hannu; Lauri, Janne; Fabritius, Tapio; Jedrzejewska-Szczerska, Małgorzata; Kiviniemi, Vesa; Meglinski, Igor

2017-03-01

In brain studies, the function of the cerebrospinal fluid (CSF) awakes growing interest, particularly related to studies of the glymphatic system in the brain, which is connected with the complex system of lymphatic vessels responsible for cleaning the tissues. The CSF is a clear, colourless liquid including water (H2O) approximately with a concentration of 99 %. In addition, it contains electrolytes, amino acids, glucose, and other small molecules found in plasma. The CSF acts as a cushion behind the skull, providing basic mechanical as well as immunological protection to the brain. Disturbances of the CSF circulation have been linked to several brain related medical disorders, such as dementia. Our goal is to develop an in vivo method for the non-invasive measurement of cerebral blood flow and CSF circulation by exploiting optical and capacitive sensing techniques simultaneously. We introduce a prototype of a wearable probe that is aimed to be used for long-term brain monitoring purposes, especially focusing on studies of the glymphatic system. In this method, changes in cerebral blood flow, particularly oxy- and deoxyhaemoglobin, are measured simultaneously and analysed with the response gathered by the capacitive sensor in order to distinct the dynamics of the CSF circulation behind the skull. Presented prototype probe is tested by measuring liquid flows inside phantoms mimicking the CSF circulation.

Magnetohydrodynamic pressure drop and flow balancing of liquid metal flow in a prototypic fusion blanket manifold

NASA Astrophysics Data System (ADS)

Rhodes, Tyler J.; Smolentsev, Sergey; Abdou, Mohamed

2018-05-01

Understanding magnetohydrodynamic (MHD) phenomena associated with the flow of electrically conducting fluids in complex geometry ducts subject to a strong magnetic field is required to effectively design liquid metal (LM) blankets for fusion reactors. Particularly, accurately predicting the 3D MHD pressure drop and flow distribution is important. To investigate these topics, we simulate a LM MHD flow through an electrically non-conducting prototypic manifold for a wide range of flow and geometry parameters using a 3D MHD solver, HyPerComp incompressible MHD solver for arbitrary geometry. The reference manifold geometry consists of a rectangular feeding duct which suddenly expands such that the duct thickness in the magnetic field direction abruptly increases by a factor rexp. Downstream of the sudden expansion, the LM is distributed into several parallel channels. As a first step in qualifying the flow, a magnitude of the curl of the induced Lorentz force was used to distinguish between inviscid, irrotational core flows and boundary and internal shear layers where inertia and/or viscous forces are important. Scaling laws have been obtained which characterize the 3D MHD pressure drop and flow balancing as a function of the flow parameters and the manifold geometry. Associated Hartmann and Reynolds numbers in the computations were ˜103 and ˜101-103, respectively, while rexp was varied from 4 to 12. An accurate model for the pressure drop was developed for the first time for inertial-electromagnetic and viscous-electromagnetic regimes based on 96 computed cases. Analysis shows that flow balance can be improved by lengthening the distance between the manifold inlet and the entrances of the parallel channels by utilizing the effect of flow transitioning to a quasi-two-dimensional state in the expansion region of the manifold.

Prototype Development and Evaluation of Self-Cleaning Concentrated Solar Power Collectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazumder, Malay K.; Horenstein, Mark N.; Joglekar, Nitin R.

The feasibility of integrating and retrofitting transparent electrodynamic screens (EDS) on the front surfaces of solar collectors was established as a means to provide active self-cleaning properties for parabolic trough and heliostat reflectors, solar panels, and Fresnel lenses. Prototype EDS-integrated solar collectors, including second-surface glass mirrors, metallized Acrylic-film mirrors, and dielectric mirrors, were produced and tested in environmental test chambers for removing the dust layer deposited on the front surface of the mirrors. The evaluation of the prototype EDS-integrated mirrors was conducted using dust and environmental conditions that simulate the field conditions of the Mojave Desert. Test results showed thatmore » the specular reflectivity of the mirrors could be maintained at over 90% over a wide range of dust loadings ranging from 0 to 10 g/m 2, with particle diameter varying from 1 to 50 μm. The measurement of specular reflectivity (SR) was performed using a D&S Reflectometer at wavelength 660 nm. A non-contact reflectometer was designed and constructed for rapid measurement of specular reflectivity at the same wavelength. The use of this new noncontact instrument allowed us to measure SR before and after EDS activation. Several EDS prototypes were constructed and evaluated with different electrode configurations, electrode materials, and encapsulating dielectric materials.« less

Design and characterization of a prototype enzyme microreactor: quantification of immobilized transketolase kinetics.

PubMed

Matosevic, S; Lye, G J; Baganz, F

2010-01-01

In this work, we describe the design of an immobilized enzyme microreactor (IEMR) for use in transketolase (TK) bioconversion process characterization. The prototype microreactor is based on a 200-microm ID fused silica capillary for quantitative kinetic analysis. The concept is based on the reversible immobilization of His(6)-tagged enzymes via Ni-NTA linkage to surface derivatized silica. For the initial microreactor design, the mode of operation is a stop-flow analysis which promotes higher degrees of conversion. Kinetics for the immobilized TK-catalysed synthesis of L-erythrulose from substrates glycolaldehyde (GA) and hydroxypyruvate (HPA) were evaluated based on a Michaelis-Menten model. Results show that the TK kinetic parameters in the IEMR (V(max(app)) = 0.1 +/- 0.02 mmol min(-1), K(m(app)) = 26 +/- 4 mM) are comparable with those measured in free solution. Furthermore, the k(cat) for the microreactor of 4.1 x 10(5) s(-1) was close to the value for the bioconversion in free solution. This is attributed to the controlled orientation and monolayer surface coverage of the His(6)-immobilized TK. Furthermore, we show quantitative elution of the immobilized TK and the regeneration and reuse of the derivatized capillary over five cycles. The ability to quantify kinetic parameters of engineered enzymes at this scale has benefits for the rapid and parallel evaluation of evolved enzyme libraries for synthetic biology applications and for the generation of kinetic models to aid bioconversion process design and bioreactor selection as a more efficient alternative to previously established microwell-based systems for TK bioprocess characterization.

Electrochemical lateral flow immunosensor for detection and quantification of dengue NS1 protein.

PubMed

Sinawang, Prima Dewi; Rai, Varun; Ionescu, Rodica E; Marks, Robert S

2016-03-15

An Electrochemical Lateral Flow Immunosensor (ELFI) is developed combining screen-printed gold electrodes (SPGE) enabling quantification together with the convenience of a lateral flow test strip. A cellulose glassy fiber paper conjugate pad retains the marker immunoelectroactive nanobeads which will bind to the target analyte of interest. The specific immunorecognition event continues to occur along the lateral flow bed until reaching the SPGE-capture antibodies at the end of the cellulosic lateral flow strip. The rationale of the immunoassay consists in the analyte antigen NS1 protein being captured selectively and specifically by the dengue NS1 antibody conjugated onto the immunonanobeads thus forming an immunocomplex. With the aid of a running buffer, the immunocomplexes flow and reach the immuno-conjugated electrode surface and form specific sandwich-type detection due to specific, molecular recognition, while unbound beads move along past the electrodes. The successful sandwich immunocomplex formation is then recorded electrochemically. Specific detection of NS1 is translated into an electrochemical signal contributed by a redox label present on the bead-immobilized detection dengue NS1 antibody while a proportional increase of faradic current is observed with increase in analyte NS1 protein concentration. The first generation ELFI prototype is simply assembled in a cassette and successfully demonstrates wide linear range over a concentration range of 1-25 ng/mL with an ultrasensitive detection limit of 0.5 ng/mL for the qualitative and quantitative detection of analyte dengue NS1 protein. Copyright © 2015 Elsevier B.V. All rights reserved.

A direct-interface, fusible heat sink for astronaut cooling

NASA Technical Reports Server (NTRS)

Lomax, Curtis; Webbon, B. W.

1990-01-01

Astronaut cooling during extravehicular activity is a critical design issue in developing a portable life support system that meets the requirements of a space station mission. Some of the requirements are that the cooling device can be easily regenerable and nonventing during operation. In response to this, a direct-interface, fusible heat sink prototype with freezable quick-disconnects was developed. A proof-of-concept prototype was constructed and tested that consists of an elastic container filled with normal tap water and having two quick-disconnects embedded in a wall. These quick-disconnects are designed so that they may be frozen with the ice and yet still be joined to the cooling system, allowing an immediate flow path. The inherent difficulties in a direct-interface heat sink have been overcome, i.e., (1) establishing an initial flow path; (2) avoiding low-flow freeze-up; and (3) achieving adequate heat-transfer rates at the end of the melting process. The requirements, design, fabrication, and testing are discussed.

Development of the prototype data management system of the solar H-alpha full disk observation

NASA Astrophysics Data System (ADS)

Wei, Ka-Ning; Zhao, Shi-Qing; Li, Qiong-Ying; Chen, Dong

2004-06-01

The Solar Chromospheric Telescope in Yunnan Observatory generates about 2G bytes fits format data per day. Huge amounts of data will bring inconvenience for people to use. Hence, data searching and sharing are important at present. Data searching, on-line browsing, remote accesses and download are developed with a prototype data management system of the solar H-alpha full disk observation, and improved by the working flow technology. Based on Windows XP operating system and MySQL data management system, a prototype system of browse/server model is developed by JAVA and JSP. Data compression, searching, browsing, deletion need authority and download in real-time have been achieved.

Space station prototype Sabatier reactor design verification testing

NASA Technical Reports Server (NTRS)

Cusick, R. J.

1974-01-01

A six-man, flight prototype carbon dioxide reduction subsystem for the SSP ETC/LSS (Space Station Prototype Environmental/Thermal Control and Life Support System) was developed and fabricated for the NASA-Johnson Space Center between February 1971 and October 1973. Component design verification testing was conducted on the Sabatier reactor covering design and off-design conditions as part of this development program. The reactor was designed to convert a minimum of 98 per cent hydrogen to water and methane for both six-man and two-man reactant flow conditions. Important design features of the reactor and test conditions are described. Reactor test results are presented that show design goals were achieved and off-design performance was stable.

Dynamical and fractal properties in periodically forced stretch-twist-fold (STF) flow

NASA Astrophysics Data System (ADS)

Aqeel, Muhammad; Ahmad, Salman; Azam, Anam; Ahmed, Faizan

2017-05-01

The periodically forced stretch-twist-fold (STF) flow is introduced in this article. The nonlinear behavior of the STF flow with periodic force along the y -axis is investigated analytically and numerically. The STF flow is a prototype of the dynamo theory that proposes a mechanism of magnetic field generation continuously. The stability analysis is done by Routh Huwritz criteria and Cardano method. Chasing chaos through numerical simulation is determined to demonstrate the chaotic behavior of the forced STF flow. With the help of fractal processes based on the forced STF flow, a multi-wing forced STF flow is obtained that gives a n -wing forced STF flow system.

X-ray monochromators for high-power synchrotron radiation sources

NASA Astrophysics Data System (ADS)

Hart, Michael

1990-11-01

Exact solutions to the problems of power flow from a line source of heat into a semicylinder and of uniform heat flow normal to a flat surface are discussed. These lead to bounds on feasible designs and the boundary layer problem can be placed in proper perspective. While finite element calculations are useful if the sample boundaries are predefined, they are much less help in establishing design principles. Previous work on hot beam X-ray crystal optics has emphasised the importance of coolant hydraulics and boundary layer heat transfer. Instead this paper emphasises the importance of the elastic response of crystals to thermal strainfields and the importance of maintaining the Darwin reflectivity. The conclusions of this design study are that the diffracting crystal region should be thin, but not very thin, similar in area to the hot beam footprint, part of a thin-walked buckling crystal box and remote from the support to which the crystal is rigidly clamped. Prototype 111 and 220 cooled silicon crystals tested at the National Synchrotron Light Source at Brookhaven have almost perfect rocking curves under a beam heat load of {1}/{3}kW.

Laser sintering fabrication of three-dimensional tissue engineering scaffolds with a flow channel network.

PubMed

Niino, T; Hamajima, D; Montagne, K; Oizumi, S; Naruke, H; Huang, H; Sakai, Y; Kinoshita, H; Fujii, T

2011-09-01

The fabrication of tissue engineering scaffolds for the reconstruction of highly oxygen-dependent inner organs is discussed. An additive manufacturing technology known as selective laser sintering was employed to fabricate a highly porous scaffold with an embedded flow channel network. A porogen leaching system was used to obtain high porosity. A prototype was developed using the biodegradable plastic polycaprolactone and sodium chloride as the porogen. A high porosity of 90% was successfully obtained. Micro x-ray CT observation was carried out to confirm that channels with a diameter of approximately 1 mm were generated without clogging. The amount of residual salt was 930 µg while the overall volume of the scaffold was 13 cm(3), and it was confirmed that the toxicity of the salt was negligible. The hydrophilization of the scaffold to improve cell adhesion on the scaffold is also discussed. Oxygen plasma ashing and hydrolysis with sodium hydroxide, typically employed to improve the hydrophilicity of plastic surfaces, were tested. The improvement of hydrophilicity was confirmed by an increase in water retention by the porous scaffold from 180% to 500%.

An experimental study on the effect of wind load around tall towers of square and hexagonal shapes in staggered form

NASA Astrophysics Data System (ADS)

Anwar, Proma; Islam, Md. Quamrul; Ali, Mohammad

2017-06-01

In this research work an experiment is conducted to observe the effect of wind load around square and hexagonal shaped cylinders in staggered form. The experiment is performed in an open circuit wind tunnel at a Reynolds number of 4.23×104 based on the face width of the cylinder across the flow direction. The flow velocity has been kept uniform at 14.3 m/s throughout the experiment. The test is conducted for single cylinders first and then in staggered form. The cylinders are rotated to create different angles of attack and the angles are chosen at a definite interval. The static pressure readings are taken at different locations of the cylinder by inclined multi-manometers. From the surface static pressure readings pressure coefficients, drag coefficients and lift coefficients are calculated using numerical integration method. These results will surely help engineers to design buildings more stable against wind load. All the results are expressed in non-dimensional form, so that they can be applied for prototype structures.

Diurnal evolution of wind structure and data availability measured by the DOE prototype radar system

NASA Astrophysics Data System (ADS)

Hirth, Brian D.; Schroeder, John L.; Guynes, Jerry G.

2017-11-01

A new Doppler radar prototype has been developed and deployed at Texas Tech University with a focus on enhancing the technologies’ capability to contribute to wind plant relevant complex flow measurements. In particular, improvements in data availability, total data coverage, and autonomous operation were targeted to enable contributions to a wider range of wind energy applications. Doppler radar offers rapid scan speeds, extended maximum range and excellent along-beam range resolution allowing for the simultaneous measurement of various wind phenomena ranging from regional and wind plant scales to inflow and wake flow assessment for an individual turbine. Data examples and performance improvements relative to a previous edition of the technology are presented, including insights into the influence of diurnal atmospheric stability evolution of wind structure and system performance.

Planar array stack design aided by rapid prototyping in development of air-breathing PEMFC

NASA Astrophysics Data System (ADS)

Chen, Chen-Yu; Lai, Wei-Hsiang; Weng, Biing-Jyh; Chuang, Huey-Jan; Hsieh, Ching-Yuan; Kung, Chien-Chih

The polymer electrolyte membrane fuel cell (PEMFC) is one of the most important research topics in the new and clean energy area. The middle or high power PEMFCs can be applied to the transportation or the distributed power system. But for the small power application, it is needed to match the power requirement of the product generally. On the other hand, the direct methanol fuel cell (DMFC) is one of the most common type that researchers are interested in, but recently the miniature or the micro-PEMFCs attract more attention due to their advantages of high open circuit voltage and high power density. The objective of this study is to develop a new air-breathing planar array fuel cell stacked from 10 cells made by rapid prototyping technology which has potential for fast commercial design, low cost manufacturing, and even without converters/inverters for the system. In this paper, the main material of flow field plates is acrylonitrile-butadiene-styrene (ABS) which allows the fuel cell be mass-manufactured by plastic injection molding technology. The rapid prototyping technology is applied to construct the prototype and verify the practicability of the proposed stack design. A 10-cell air-breathing miniature PEMFC stack with a volume of 6 cm × 6 cm × 0.9 cm is developed and tested. Its segmented membrane electrode assembly (MEA) is designed with the active surface area of 1.3 cm × 1.3 cm in each individual MEA. The platinum loading at anode and cathode are 0.2 mg cm -2 and 0.4 mg cm -2, respectively. Results show that the peak power densities of the parallel connected and serial connected stack are 99 mW cm -2 at 0.425 V and 92 mW cm -2 at 4.25 V, respectively under the conditions of 70 °C relative saturated humidity (i.e., dew point temperature), ambient temperature and free convection air. Besides, the stack performance is increased under forced convection. If the cell surface air is blown by an electric fan, the peak power densities of parallel connected and serial connected stack are improved to 123 mW cm -2 at 0.425 V and 105 mW cm -2 at 5.25 V, respectively. The forced convection air can not only increases the oxygen diffusion rate at the air-breathing surface, but also enhance the uniformity of output voltage distribution. The performance obtained in this work reaches to the state-of-the-air of air-breathing planar PEMFC stack comparing to recent literatures. In this study, the different behavior of output performance at water-rich region and water-lean region is also discussed.

Long-term flow monitoring of submarine gas emanations

NASA Astrophysics Data System (ADS)

Spickenbom, K.; Faber, E.; Poggenburg, J.; Seeger, C.

2009-04-01

One of the Carbon Capture and Storage (CCS) strategies currently under study is the sequestration of CO2 in sub-seabed geological formations. Even after a thorough review of the geological setting, there is the possibility of leaks from the reservoirs. As part of the EU-financed project CO2ReMoVe (Research, Monitoring, Verification), which aims to develop innovative research and technologies for monitoring and verification of carbon dioxide geological storage, we are working on the development of submarine long-term gas flow monitoring systems. Technically, however, these systems are not limited to CO2 but can be used for monitoring of any free gas emission (bubbles) on the seafloor. The basic design of the gas flow sensor system was derived from former prototypes developed for monitoring CO2 and CH4 on mud volcanoes in Azerbaijan. This design was composed of a raft floating on the surface above the gas vent to collect the bubbles. Sensors for CO2 flux and concentration and electronics for data storage and transmission were mounted on the raft, together with battery-buffered solar panels for power supply. The system was modified for installation in open sea by using a buoy instead of a raft and a funnel on the seafloor to collect the gas, which is then guided above water level through a flexible tube. Besides some technical problems (condensed water in the tube, movement of the buoys due to waves leading to biased measurement of flow rates), this setup provides a cost-effective solution for shallow waters. However, a buoy interferes with ship traffic, and it is also difficult to adapt this design to greater water depths. These requirements can best be complied by a completely submersed system. To allow unattended long-term monitoring in a submarine environment, such a system has to be extremely durable. Therefore, we focussed on developing a mechanically and electrically as simple setup as possible, which has the additional advantage of low cost. The system consists of gas collector, sensor head and pressure housing for electronics and power supply. The collector is a plastic funnel, enclosed in a stainless-steel frame to add weight and stability. The whole unit is fixed to the sediment by nails or sediment screws. The sensor head is equipped with an "inverted tipping-bucket" sensor, which basically works like a turned upside-down rain gauge. It fills with the collected gas until full, then empties completely and starts again, which allows the calculation of the flow rate by container volume and frequency of the cycle. This sensor type is very robust due to a design nearly without moving parts and suitable for very low to medium flow rates. For higher flow rates different sensor heads using turbine wheels or pressure differences can be used. The pressure housing for this prototype is made of aluminium and contains a Hobo Pendant data logger with integrated battery supply. Since this setup is inexpensive, it can be deployed in numbers to cover larger areas. By addition of multi-channel data loggers, data transmission by acoustic modem or cable, relay stations on the seafloor or buoys etc. the infrastructure can be adapted to the environmental setting and financial budget. Prototype tests under laboratory conditions as well as field tests on natural submarine gas vents as an analogue to leaking storage sites have demonstrated the capabilities and robustness of the systems.

Development of a low-cost, 11 µm spectral domain optical coherence tomography surface profilometry prototype

NASA Astrophysics Data System (ADS)

Suliali, Nyasha J.; Baricholo, Peter; Neethling, Pieter H.; Rohwer, Erich G.

2017-06-01

A spectral-domain Optical Coherence Tomography (OCT) surface profilometry prototype has been developed for the purpose of surface metrology of optical elements. The prototype consists of a light source, spectral interferometer, sample fixture and software currently running on Microsoft® Windows platforms. In this system, a broadband light emitting diode beam is focused into a Michelson interferometer with a plane mirror as its sample fixture. At the interferometer output, spectral interferograms of broadband sources were measured using a Czerny-Turner mount monochromator with a 2048-element complementary metal oxide semiconductor linear array as the detector. The software performs importation and interpolation of interferometer spectra to pre-condition the data for image computation. One dimensional axial OCT images were computed by Fourier transformation of the measured spectra. A first reflection surface profilometry (FRSP) algorithm was then formulated to perform imaging of step-function-surfaced samples. The algorithm re-constructs two dimensional colour-scaled slice images by concatenation of 21 and 13 axial scans to form a 10 mm and 3.0 mm slice respectively. Measured spectral interferograms, computed interference fringe signals and depth reflectivity profiles were comparable to simulations and correlated to displacements of a single reflector linearly translated about the arm null-mismatch point. Surface profile images of a double-step-function-surfaced sample, embedded with inclination and crack detail were plotted with an axial resolution of 11 μm. The surface shape, defects and misalignment relative to the incident beam were detected to the order of a micron, confirming high resolution of the developed system as compared to electro-mechanical surface profilometry techniques.

Onsite wastewater nitrogen reduction with expanded media and elemental sulfur biofiltration.

PubMed

Smith, D P

2012-01-01

A passive biofiltration process has been developed to enhance nitrogen removal from onsite sanitation water. The system employs an initial unsaturated vertical flow biofilter with expanded clay media (nitrification), followed in series by a horizontal saturated biofilter for denitrification containing elemental sulfur media as electron donor. A small-scale prototype was operated continuously over eight months on primary wastewater effluent with total nitrogen (TN) of 72.2 mg/L. The average hydraulic loading to the unsaturated biofilter surface was 11.9 cm/day, applied at a 30 min dosing cycle. Average effluent TN was 2.6 mg/L and average TN reduction efficiency was 96.2%. Effluent nitrogen was 1.7 mg/L as organic N, 0.93 mg/L as ammonium (NH(4)-N), and 0.03 as oxidized (NO(3) + NO(2)) N. There was no surface clogging of unsaturated media, nitrate breakthrough, or replenishment of sulfur media over eight months. Visual and microscopic examinations revealed substantially open pores with limited material accumulation on the upper surface of the unsaturated media. Material accumulation was observed at the inlet zone of the denitrification biofilter, and sulfur media exhibited surface cavities consistent with oxidative dissolution. Two-stage biofiltration is a simple and resilient system for achieving high nitrogen reductions in onsite wastewater.

An implantable centrifugal blood pump for long term circulatory support.

PubMed

Yamazaki, K; Litwak, P; Kormos, R L; Mori, T; Tagusari, O; Antaki, J F; Kameneva, M; Watach, M; Gordon, L; Umezu, M; Tomioka, J; Koyanagi, H; Griffith, B P

1997-01-01

A compact centrifugal blood pump was developed as an implantable left ventricular assist system. The impeller diameter is 40 mm and the pump dimensions are 55 x 64 mm. This first prototype was fabricated from titanium alloy, resulting in a pump weight of 400 g including a brushless DC motor. Weight of the second prototype pump was reduced to 280 g. The entire blood contacting surface is coated with diamond like carbon to improve blood compatibility. Flow rates of over 7 L/min against 100 mmHg pressure at 2,500 rpm with 9 W total power consumption have been measured. A newly designed mechanical seal with a recirculating purge system ("Cool-Seal") is used as a shaft seal. In this seal system, seal temperature is kept under 40 degrees C to prevent heat denaturation of blood proteins. Purge fluid also cools the pump motor coil and journal bearing. The purge fluid is continuously purified and sterilized by an ultrafiltration filter incorporated into the paracorporeal drive console. In vitro experiments with bovine blood demonstrated an acceptably low hemolysis rate (normalized index of hemolysis = 0.005 +/- 0.002 g/100 L). In vivo experiments are currently ongoing using calves. Via left thoracotomy, left ventricular apex-descending aorta bypass was performed utilizing a PTFE (Polytetrafluoroethylene) vascular graft, with the pump placed in the left thoracic cavity. In two in vivo experiments, pump flow rate was maintained at 5-8 L/min, and pump power consumption remained stable at 9-10 W. All plasma free hemoglobin levels were measured at < 15 mg/dl. The seal system has demonstrated good seal capability with negligible purge fluid consumption (< 0.5 ml/ day). Both animals remain under observation after 162 and 91 days of continuous pump function.

An atmospheric pressure flow reactor: Gas phase kinetics and mechanism in tropospheric conditions without wall effects

NASA Technical Reports Server (NTRS)

Koontz, Steven L.; Davis, Dennis D.; Hansen, Merrill

1988-01-01

A new type of gas phase flow reactor, designed to permit the study of gas phase reactions near 1 atm of pressure, is described. A general solution to the flow/diffusion/reaction equations describing reactor performance under pseudo-first-order kinetic conditions is presented along with a discussion of critical reactor parameters and reactor limitations. The results of numerical simulations of the reactions of ozone with monomethylhydrazine and hydrazine are discussed, and performance data from a prototype flow reactor are presented.

Theoretical analysis of 3D, transient convection and segregation in microgravity Bridgman crystal growth

NASA Astrophysics Data System (ADS)

Yeckel, Andrew; de Almeida, Valmor F.; Derby, Jeffrey J.

2000-01-01

We present results from simulations of transient acceleration (g-jitter) in both axial and transverse directions in a simplified prototype of a vertical Bridgman crystal growth system. We also present results on the effects of applying a steady magnetic field in axial or transverse directions to damp the flow. In most cases application of a magnetic field suppresses flow oscillations, but for transverse jitter at intermediate frequencies, flow oscillations grow larger. .

A model of transluminal flow of an anti-HIV microbicide vehicle: Combined elastic squeezing and gravitational sliding

NASA Astrophysics Data System (ADS)

Szeri, Andrew J.; Park, Su Chan; Verguet, Stéphane; Weiss, Aaron; Katz, David F.

2008-08-01

Elastohydrodynamic lubrication over soft substrates is of importance in a number of biomedical problems: From lubrication of the eye surface by the tear film, to lubrication of joints by synovial fluid, to lubrication between the pleural surfaces that protect the lungs and other organs. Such flows are also important for the drug delivery functions of vehicles for anti-HIV topical microbicides. These are intended to inhibit transmission into vulnerable mucosa, e.g., in the vagina. First generation prototype microbicides have gel vehicles, which spread after insertion and coat luminal surfaces. Effectiveness derives from potency of the active ingredients and completeness and durability of coating. Delivery vehicle rheology, luminal biomechanical properties, and the force due to gravity influence the coating mechanics. We develop a framework for understanding the relative importance of boundary squeezing and body forces on the extent and speed of the coating that results. A single dimensionless number, independent of viscosity, characterizes the relative influences of squeezing and gravitational acceleration on the shape of spreading in the Newtonian case. A second scale, involving viscosity, determines the spreading rate. In the case of a shear-thinning fluid, the Carreau number also plays a role. Numerical solutions were developed for a range of the dimensionless parameter and compared well with asymptotic theory in the limited case where such results can be obtained. Results were interpreted with respect to trade-offs between wall elasticity, longitudinal forces, bolus viscosity, and bolus volume. These provide initial insights of practical value for formulators of gel delivery vehicles for anti-HIV microbicidal formulations.

Design specifications for NALDA (Naval Aviation Logistics Data Analysis) CAI (computer aided instruction): Phase 2, Interim report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Twitty, A.F.; Handler, B.H.; Duncan, L.D.

Data Systems Engineering Organization (DSEO) personnel are developing a prototype computer aided instruction (CAI) system for the Naval Aviation Logistics Data Analysis (NALDA) system. The objective of this project is to provide a prototype for implementing CAI as an enhancement to existing NALDA training. The CAI prototype project is being performed in phases. The task undertaken in Phase I was to analyze the problem and the alternative solutions and to develop a set of recommendations on how best to proceed. In Phase II a structured design and specification document was completed that will provide the basis for development and implementationmore » of the desired CAI system. Phase III will consist of designing, developing, and testing a user interface which will extend the features of the Phase II prototype. The design of the CAI prototype has followed a rigorous structured analysis based on Yourdon/DeMarco methodology and Information Engineering tools. This document includes data flow diagrams, a data dictionary, process specifications, an entity-relationship diagram, a curriculum description, special function key definitions, and a set of standards developed for the NALDA CAI Prototype.« less

Latest R&D news and beam test performance of the highly granular SiW-ECAL technological prototype for the ILC

NASA Astrophysics Data System (ADS)

Irles, A.

2018-02-01

High precision physics at future colliders as the International Linear Collider (ILC) require unprecedented high precision in the determination of the energy of final state particles. The needed precision will be achieved thanks to the Particle Flow algorithms (PF) which require highly granular and hermetic calorimeters systems. The physical proof of concept of the PF was performed in the previous campaign of beam tests of physic prototypes within the CALICE collaboration. One of these prototypes was the physics prototype of the Silicon-Tungsten Electromagnetic Calorimeter (SiW-ECAL) for the ILC. In this document we present the latest news on R&D of the next generation prototype, the technological prototype with fully embedded very front-end (VFE) electronics, of the SiW-ECAL. Special emphasis is given to the presentation and discussion of the first results from the beam test done at DESY in June 2017. The physics program for such beam test consisted in the calibration and commissioning of the current set of available SiW ECAL modules; the test of performance of individual slabs under 1T magnetic fields; and the study of electromagnetic showers events.

Prototype of the Modular Equipment Transporter (MET)

NASA Technical Reports Server (NTRS)

1970-01-01

A prototype of the Modular Equipment Transporter (MET), nicknamed the 'Rickshaw' after its shape and method of propulsion. This equipment was used by the Apollo 14 astronauts during their geological and lunar surface simulation training in the Pinacate volcanic area of northwestern Sonora, Mexico. The Apollo 14 crew will be the first one to use the MET. It will be a portable workbench with a place for the lunar handtools and their carrier, three cameras, two sample container bags, a Special Environmental Sample Container, spare film magazines, and a Lunar Surface Penetrometer.

Microencapsulation of bioactive principles with an airless spray-gun suitable for processing high viscous solutions.

PubMed

Cocchietto, Moreno; Blasi, Paolo; Lapasin, Romano; Moro, Chiara; Gallo, Davide; Sava, Gianni

2013-11-19

to design, assemble and test a prototype of a novel production plant, suitable for producing microparticles (MPs) by processing highly viscous feed solutions (FSs). the prototype has been built using a commercial air compressor, a piston pump, an airless spray-gun, a customized air-treatment section, a timer, a rotating base, and a filtration section. Preliminary prototype parameter setting was carried out to individuate the best performing nozzle's dimension, the nebulization timing, and the CaCl2 concentration in the gelation fluid. In addition, prototype throughput (1 L to 5 L) and the range of practicable feed solution (FS) viscosities were assayed. A set of four batches was prepared in order to characterize the MPs, in terms of mean particle size and distribution, flow properties, swelling, encapsulation efficiency and release. according to a qualitative scoring, the large nozzle was suitable to nebulize FSs at a higher alginate concentration. Conversely, the small nozzle performed better in the processing of FSs with an alginate concentration up to 2% w/v. Only at the highest degree of viscosity, corresponding to 5% w/v of alginate, the FS processing was not technically possible. Among the CaCl2 concentrations considered, 15% w/v was recognized as the most versatile. The prototype appears to be convenient and suitable to grant a high yield starting from 2 L of FS. The flow behavior of the FSs assayed can be satisfactorily described with the Carreau-Yasuda equation and the throughput begins to slightly decrease for FSs at alginate concentrations exceeding 3% w/v. MP morphology was irregular with crumpled shape. The angle of repose indicates a good flowability and the release studies showed gastro-resistance and potential prolonged release applications. the novel prototype of production plant is suitable to process large amounts (2 L or more) of FSs, characterized by a high viscosity, to produce MPs suitable for bioactive principle delivery.

Microencapsulation of Bioactive Principles with an Airless Spray-Gun Suitable for Processing High Viscous Solutions

PubMed Central

Cocchietto, Moreno; Blasi, Paolo; Lapasin, Romano; Moro, Chiara; Gallo, Davide; Sava, Gianni

2013-01-01

Purpose: to design, assemble and test a prototype of a novel production plant, suitable for producing microparticles (MPs) by processing highly viscous feed solutions (FSs). Methods: the prototype has been built using a commercial air compressor, a piston pump, an airless spray-gun, a customized air-treatment section, a timer, a rotating base, and a filtration section. Preliminary prototype parameter setting was carried out to individuate the best performing nozzle’s dimension, the nebulization timing, and the CaCl2 concentration in the gelation fluid. In addition, prototype throughput (1 L to 5 L) and the range of practicable feed solution (FS) viscosities were assayed. A set of four batches was prepared in order to characterize the MPs, in terms of mean particle size and distribution, flow properties, swelling, encapsulation efficiency and release. Results: according to a qualitative scoring, the large nozzle was suitable to nebulize FSs at a higher alginate concentration. Conversely, the small nozzle performed better in the processing of FSs with an alginate concentration up to 2% w/v. Only at the highest degree of viscosity, corresponding to 5% w/v of alginate, the FS processing was not technically possible. Among the CaCl2 concentrations considered, 15% w/v was recognized as the most versatile. The prototype appears to be convenient and suitable to grant a high yield starting from 2 L of FS. The flow behavior of the FSs assayed can be satisfactorily described with the Carreau-Yasuda equation and the throughput begins to slightly decrease for FSs at alginate concentrations exceeding 3% w/v. MP morphology was irregular with crumpled shape. The angle of repose indicates a good flowability and the release studies showed gastro-resistance and potential prolonged release applications. Conclusions: the novel prototype of production plant is suitable to process large amounts (2 L or more) of FSs, characterized by a high viscosity, to produce MPs suitable for bioactive principle delivery. PMID:24956192

Self pressuring HTP feed systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitehead, J.

1999-10-14

Hydrogen peroxide tanks can be pressurized with decomposed HTP (high test hydrogen peroxide) originating in the tank itself. In rocketry, this offers the advantage of eliminating bulky and heavy inert gas storage. Several prototype self-pressurizing HTP systems have recently been designed and tested. Both a differential piston tank and a small gas-driven pump have been tried to obtain the pressure boost needed for flow through a gas generator and back to the tank. Results include terrestrial maneuvering tests of a prototype microsatellite, including warm gas attitude control jets.

STS-40 DTO 647 prototype filter documented under OV-102's middeck subfloor

NASA Image and Video Library

1991-06-14

STS040-34-001 (5-14 June 1991) --- This 35mm scene shows a close-up of a prototype filter designed to remove contamination from air and water, before it flows into the Orbiter's humidity separators. This experiment is part of Development Test Objective (DTO) 647, Water Separator Filter Performance Evaluation. Astronauts Bryan D. O'Connor, mission commander, and Sidney M. Gutierrez, pilot, carried out the test and down linked television to the ground for engineering analysis.

Development of a prototype real-time automated filter for operational deep space navigation

NASA Technical Reports Server (NTRS)

Masters, W. C.; Pollmeier, V. M.

1994-01-01

Operational deep space navigation has been in the past, and is currently, performed using systems whose architecture requires constant human supervision and intervention. A prototype for a system which allows relatively automated processing of radio metric data received in near real-time from NASA's Deep Space Network (DSN) without any redesign of the existing operational data flow has been developed. This system can allow for more rapid response as well as much reduced staffing to support mission navigation operations.

Performance analysis of a new hypersonic vitrector system.

PubMed

Stanga, Paulo Eduardo; Pastor-Idoate, Salvador; Zambrano, Isaac; Carlin, Paul; McLeod, David

2017-01-01

To evaluate porcine vitreous flow and water flow rates in a new prototype hypersonic vitrectomy system compared to currently available pneumatic guillotine vitrectors (GVs) systems. Two vitrectors were tested, a prototype, ultrasound-powered, hypersonic vitrector (HV) and a GV. Porcine vitreous was obtained within 12 to 24 h of sacrifice and kept at 4°C. A vial of vitreous or water was placed on a precision balance and its weight measured before and after the use of each vitrector. Test parameters included changes in aspiration levels, vitrector gauge, cut rates for GVs, % ultrasound (US) power for HVs, and port size for HVs. Data was analysed using linear regression and t-tests. There was no difference in the total average mean water flow between the 25-gauge GV and the 25-gauge HV (t-test: P = 0.363); however, 25-gauge GV was superior (t-test: P < 0.001) in vitreous flow. The 23-gauge GV was only more efficient in water and vitreous removal than 23-gauge HV needle-1 (Port 0.0055) (t-test: P < 0.001). For HV, wall thickness and gauge had no effect on flow rates. Water and vitreous flows showed a direct correlation with increasing aspiration levels and % US power (p<0.05). The HV produced consistent water and vitreous flow rates across the range of US power and aspiration levels tested. Hypersonic vitrectomy may be a promising new alternative to the currently available guillotine-based technologies.

Tactile-Foot Stimulation Can Assist the Navigation of People with Visual Impairment

PubMed Central

Velázquez, Ramiro; Pissaloux, Edwige; Lay-Ekuakille, Aimé

2015-01-01

Background. Tactile interfaces that stimulate the plantar surface with vibrations could represent a step forward toward the development of wearable, inconspicuous, unobtrusive, and inexpensive assistive devices for people with visual impairments. Objective. To study how people understand information through their feet and to maximize the capabilities of tactile-foot perception for assisting human navigation. Methods. Based on the physiology of the plantar surface, three prototypes of electronic tactile interfaces for the foot have been developed. With important technological improvements between them, all three prototypes essentially consist of a set of vibrating actuators embedded in a foam shoe-insole. Perceptual experiments involving direction recognition and real-time navigation in space were conducted with a total of 60 voluntary subjects. Results. The developed prototypes demonstrated that they are capable of transmitting tactile information that is easy and fast to understand. Average direction recognition rates were 76%, 88.3%, and 94.2% for subjects wearing the first, second, and third prototype, respectively. Exhibiting significant advances in tactile-foot stimulation, the third prototype was evaluated in navigation tasks. Results show that subjects were capable of following directional instructions useful for navigating spaces. Conclusion. Footwear providing tactile stimulation can be considered for assisting the navigation of people with visual impairments. PMID:27019593

Tactile-Foot Stimulation Can Assist the Navigation of People with Visual Impairment.

PubMed

Velázquez, Ramiro; Pissaloux, Edwige; Lay-Ekuakille, Aimé

2015-01-01

Background. Tactile interfaces that stimulate the plantar surface with vibrations could represent a step forward toward the development of wearable, inconspicuous, unobtrusive, and inexpensive assistive devices for people with visual impairments. Objective. To study how people understand information through their feet and to maximize the capabilities of tactile-foot perception for assisting human navigation. Methods. Based on the physiology of the plantar surface, three prototypes of electronic tactile interfaces for the foot have been developed. With important technological improvements between them, all three prototypes essentially consist of a set of vibrating actuators embedded in a foam shoe-insole. Perceptual experiments involving direction recognition and real-time navigation in space were conducted with a total of 60 voluntary subjects. Results. The developed prototypes demonstrated that they are capable of transmitting tactile information that is easy and fast to understand. Average direction recognition rates were 76%, 88.3%, and 94.2% for subjects wearing the first, second, and third prototype, respectively. Exhibiting significant advances in tactile-foot stimulation, the third prototype was evaluated in navigation tasks. Results show that subjects were capable of following directional instructions useful for navigating spaces. Conclusion. Footwear providing tactile stimulation can be considered for assisting the navigation of people with visual impairments.

The Atchafalaya River Delta. Report 5. The Atchafalaya River Delta Quasi-Two-Dimensional Model of Delta Growth and Impacts on River Stages

DTIC Science & Technology

1988-12-01

report are not to be used for advertising , publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or...from van Beek et al. (1979). This comparison shows very good agreement between MCM and prototype flow distribution. 71 100% SIMM ESPORT FLOW MILE 55

Experimental modeling of swirl flows in power plants

NASA Astrophysics Data System (ADS)

Shtork, S. I.; Litvinov, I. V.; Gesheva, E. S.; Tsoy, M. A.; Skripkin, S. G.

2018-03-01

The article presents an overview of the methods and approaches to experimental modeling of various thermal and hydropower units - furnaces of pulverized coal boilers and flow-through elements of hydro turbines. The presented modeling approaches based on a combination of experimentation and rapid prototyping of working parts may be useful in optimizing energy equipment to improve safety and efficiency of industrial energy systems.

Smart monolithic integration of inkjet printed thermal flow sensors with fast prototyping polymer microfluidics

NASA Astrophysics Data System (ADS)

Etxebarria, Ikerne; Elizalde, Jorge; Pacios, Roberto

2016-08-01

There is an increasing demand for built-in flow sensors in order to effectively control microfluidic processes due to the high number of available microfluidic applications. The possible solutions should be inexpensive and easy to connect to both, the microscale features and the macro setup. In this paper, we present a novel approach to integrate a printed thermal flow sensor with polymeric microfluidic channels. This approach is focused on merging two high throughput production processes, namely inkjet printing and fast prototyping technologies, in order to produce trustworthy and low cost devices. These two technologies are brought together to obtain a sensor located outside the microfluidic device. This avoids the critical contact between the sensor material and the fluids through the microchannels that can seriously damage the conducting paths under continuous working regimes. In this way, we ensure reliable and stable operation modes. For this application, a silver nanoparticle based ink and cyclic olefin polymer were used. This flow sensor operates linearly in the range of 0-10 μl min-1 for water and 0-20 μl min-1 for ethanol in calorimetric mode. Switching to anemometric mode, the range can be expanded up to 40 μl min-1.

Three-dimensional computational fluid dynamics modeling of particle uptake by an occupational air sampler using manually-scaled and adaptive grids

PubMed Central

Landázuri, Andrea C.; Sáez, A. Eduardo; Anthony, T. Renée

2016-01-01

This work presents fluid flow and particle trajectory simulation studies to determine the aspiration efficiency of a horizontally oriented occupational air sampler using computational fluid dynamics (CFD). Grid adaption and manual scaling of the grids were applied to two sampler prototypes based on a 37-mm cassette. The standard k–ε model was used to simulate the turbulent air flow and a second order streamline-upwind discretization scheme was used to stabilize convective terms of the Navier–Stokes equations. Successively scaled grids for each configuration were created manually and by means of grid adaption using the velocity gradient in the main flow direction. Solutions were verified to assess iterative convergence, grid independence and monotonic convergence. Particle aspiration efficiencies determined for both prototype samplers were undistinguishable, indicating that the porous filter does not play a noticeable role in particle aspiration. Results conclude that grid adaption is a powerful tool that allows to refine specific regions that require lots of detail and therefore better resolve flow detail. It was verified that adaptive grids provided a higher number of locations with monotonic convergence than the manual grids and required the least computational effort. PMID:26949268

Flow instabilities in non-uniformly heated helium jet arrays used for divertor PFCs

DOE PAGES

Youchison, Dennis L.

2015-07-30

In this study, due to a lack of prototypical experimental data, little is known about the off-normal behavior of recently proposed divertor jet cooling concepts. This article describes a computational fluid dynamics (CFD) study on two jet array designs to investigate their susceptibility to parallel flow instabilities induced by non-uniform heating and large increases in the helium outlet temperature. The study compared a single 25-jet helium-cooled modular divertor (HEMJ) thimble and a micro-jet array with 116 jets. Both have pure tungsten armor and a total mass flow rate of 10 g/s at a 600 °C inlet temperature. We investigated flowmore » perturbations caused by a 30 MW/m 2 off-normal heat flux applied over a 25 mm 2 area in addition to the nominal 5 MW/m 2 applied over a 75 mm 2 portion of the face. The micro-jet array exhibited lower temperatures and a more uniform surface temperature distribution than the HEMJ thimble. We also investigated the response of a manifolded nine-finger HEMJ assembly using the nominal heat flux and a 274 mm 2 heated area. For the 30 MW/m2 case, the micro-jet array absorbed 750 W in the helium with a maximum armor surface temperature of 1280 °C and a fluid/solid interface temperature of 801 °C. The HEMJ absorbed 750 W with a maximum armor surface temperature of 1411 °C and a fluid/solid interface temperature of 844 °C. For comparison, both the single HEMJ finger and the micro-jet array used 5-mm-thick tungsten armor. The ratio of maximum to average temperature and variations in the local heat transfer coefficient were lower for the micro-jet array compared to the HEMJ device. Although high heat flux testing is required to validate the results obtained in these simulations, the results provide important guidance in jet design and manifolding to increase heat removal while providing more even temperature distribution and minimizing non-uniformity in the gas flow and thermal stresses at the armor joint.« less

Prototyping hexagonal light concentrators using high-reflectance specular films for the Large-Sized Telescopes of the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Okumura, A.; Dang, T. V.; Ono, S.; Tanaka, S.; Hayashida, M.; Hinton, J.; Katagiri, H.; Noda, K.; Teshima, M.; Yamamoto, T.; Yoshida, T.

2017-12-01

We have developed a prototype hexagonal light concentrator for the Large-Sized Telescopes of the Cherenkov Telescope Array. To maximize the photodetection efficiency of the focal-plane camera pixels for atmospheric Cherenkov photons and to lower the energy threshold, a specular film with a very high reflectance of 92-99% has been developed to cover the inner surfaces of the light concentrators. The prototype has a relative anode sensitivity (which can be roughly regarded as collection efficiency) of about 95 to 105% at the most important angles of incidence. The design, simulation, production procedure, and performance measurements of the light-concentrator prototype are reported.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ermanoski, Ivan; Orozco, Adrian

In this report we present the development of a packed particle bed recirculator and heat exchanger. The device is intended to create countercurrent flows of packed particle beds and exchange heat between the flows. The project focused on the design, fabrication, demonstration, and modifications of a simple prototype, in order to attain high levels of heat exchange between particle flows while maintaining an effective particle conveying rate in a scalable package. Despite heat losses in a package not optimized for heat retention, 50% heat recovery was achieved, at a particle conveying efficiency of 40%.

An Experimental Examination of the Loss-of-Flow Accident Phenomenon for Prototypical ITER Divertor Channels of Y = 0 and Y = 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marshall, Theron D.; McDonald, Jimmie M.; Cadwallader, Lee C.

2000-01-15

This paper discusses the thermal response of two prototypical International Thermonuclear Experimental Reactor (ITER) divertor channels during simulated loss-of-flow-accident (LOFA) experiments. The thermal response was characterized by the time-to-burnout (TBO), which is a figure of merit on the mockups' survivability. Data from the LOFA experiments illustrate that (a) the pre-LOFA inlet velocity does not significantly influence the TBO, (b) the incident heat flux (IHF) does influence the TBO, and (c) a swirl tape insert significantly improves the TBO and promotes the initiation of natural circulation. This natural circulation enabled the mockup to absorb steady-state IHFs after the coolant circulation pumpmore » was disabled. Several methodologies for thermal-hydraulic modeling of the LOFA were attempted.« less

An experimental examination of the loss-of-flow accident phenomenon for prototypical ITER divertor channels of Y=0 and Y=2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marshall, T.D.; McDonald, J.M.; Cadwallader, L.C.

2000-01-01

This paper discusses the thermal response of two prototypical International Thermonuclear Experimental Reactor (ITER) divertor channels during simulated loss-of-flow-accident (LOFA) experiments. The thermal response was characterized by the time-to-burnout (TBO), which is a figure of merit on the mockups' survivability. Data from the LOFA experiments illustrate that (a) the pre-LOFA inlet velocity does not significantly influence the TBO, (b) the incident heat flux (IHF) does influence the TBO, and (c) a swirl tape insert significantly improves the TBO and promotes the initiation of natural circulation. This natural circulation enabled the mockup to absorb steady-state IHFs after the coolant circulation pumpmore » was disabled. Several methodologies for thermal-hydraulic modeling of the LOFA were attempted.« less

Heart Pump Design for Cleveland Clinic Foundation

NASA Technical Reports Server (NTRS)

2005-01-01

Through a Lewis CommTech Program project with the Cleveland Clinic Foundation, the NASA Lewis Research Center is playing a key role in the design and development of a permanently implantable, artificial heart pump assist device. Known as the Innovative Ventricular Assist System (IVAS), this device will take on the pumping role of the damaged left ventricle of the heart. The key part of the IVAS is a nonpulsatile (continuous flow) artificial heart pump with centrifugal impeller blades, driven by an electric motor. Lewis is part of an industry and academia team, led by the Ohio Aerospace Institute (OAI), that is working with the Cleveland Clinic Foundation to make IVAS a reality. This device has the potential to save tens of thousands of lives each year, since 80 percent of heart attack victims suffer irreversible damage to the left ventricle, the part of the heart that does most of the pumping. Impeller blade design codes and flow-modeling analytical codes will be used in the project. These codes were developed at Lewis for the aerospace industry but will be applicable to the IVAS design project. The analytical codes, which currently simulate the flow through the compressor and pump systems, will be used to simulate the flow within the blood pump in the artificial heart assist device. The Interdisciplinary Technology Office heads up Lewis' efforts in the IVAS project. With the aid of numerical modeling, the blood pump will address many design issues, including some fluid-dynamic design considerations that are unique to the properties of blood. Some of the issues that will be addressed in the design process include hemolysis, deposition, recirculation, pump efficiency, rotor thrust balance, and bearing lubrication. Optimum pumping system performance will be achieved by modeling all the interactions between the pump components. The interactions can be multidisciplinary and, therefore, are influenced not only by the fluid dynamics of adjacent components but also by thermal and structural effects. Lewis-developed flow-modeling codes to be used in the pump simulations will include a one-dimensional code and an incompressible three-dimensional Navier-Stokes flow code. These codes will analyze the prototype pump designed by the Cleveland Clinic Foundation. With an improved understanding of the flow phenomena within the prototype pump, design changes to improve the performance of the pump system can be verified by computer prior to fabrication in order to reduce risks. The use of Lewis flow modeling codes during the design and development process will improve pump system performance and reduce the number of prototypes built in the development phase. The first phase of the IVAS project is to fully develop the prototype in a laboratory environment that uses a water/glycerin mixture as the surrogate fluid to simulate blood. A later phase of the project will include testing in animals for final validation. Lewis will be involved in the IVAS project for 3 to 5 years.

Translating expert system rules into Ada code with validation and verification

NASA Technical Reports Server (NTRS)

Becker, Lee; Duckworth, R. James; Green, Peter; Michalson, Bill; Gosselin, Dave; Nainani, Krishan; Pease, Adam

1991-01-01

The purpose of this ongoing research and development program is to develop software tools which enable the rapid development, upgrading, and maintenance of embedded real-time artificial intelligence systems. The goals of this phase of the research were to investigate the feasibility of developing software tools which automatically translate expert system rules into Ada code and develop methods for performing validation and verification testing of the resultant expert system. A prototype system was demonstrated which automatically translated rules from an Air Force expert system was demonstrated which detected errors in the execution of the resultant system. The method and prototype tools for converting AI representations into Ada code by converting the rules into Ada code modules and then linking them with an Activation Framework based run-time environment to form an executable load module are discussed. This method is based upon the use of Evidence Flow Graphs which are a data flow representation for intelligent systems. The development of prototype test generation and evaluation software which was used to test the resultant code is discussed. This testing was performed automatically using Monte-Carlo techniques based upon a constraint based description of the required performance for the system.

Bioregenerative system components for microgravity

NASA Technical Reports Server (NTRS)

Nevill, Gale E., Jr.; Hessel, Michael I., Jr.

1992-01-01

The goal of the class was to design, fabricate, and test prototype designs that were independent, yet applicable to a Closed Loop Life Support System. The three prototypes chosen were in the areas of agar plant growth, regnerative filtration, and microgravity food preparation. The plant growth group designed a prototype agar medium growth system that incorporates nutrient solution replenishment and post-harvest refurbishment. In addition, the unit emphasizes material containment and minimization of open interfaces. The second project was a filter used in microgravity that has the capability to clean itself. The filters are perforated plates which slide through a duct and are cleaned outside of the flow with a vacuum system. The air in the duct is prevented from flowing outside of the duct by a network of sliding seals. The food preparation group developed a device which dispenses and mixes ingredients and then cooks the mixture in microgravity. The dry ingredients are dispensed from a canister by a ratchet-operated piston. The wet ingredients are dispensed from plastic bags through tubing attached to a syringe. Once inside the mixing chamber, the ingredients are mixed using a collapsible whisk and then pushed into the cooking device.

An acoustic sensor for monitoring airflow in pediatric tracheostomy patients.

PubMed

Ruscher, Thomas; Wicks Phd, Alexandrina; Muelenaer Md, Andre

2012-01-01

Without proper monitoring, patients with artificial airways in the trachea are at high risk for complications or death. Despite routine maintenance of the tube, dislodged or copious mucus can obstruct the airway. Young children ( 3yrs) have difficulty tending to their own tubes and are particularly vulnerable to blockages. They require external respiratory sensors. In a hospital environment, ventilators, end-tidal CO2 monitors, thermistors, and other auxiliary equipment provide sufficient monitoring of respiration. However, outpatient monitoring methods, such as thoracic impedance and pulse oximetry, are indirect and prone to false positives. Desensitization of caregivers to frequent false alarms has been cited in medical literature as a contributing factor in cases of child death. Ultrasonic time-of-flight (TOF) is a technique used in specialized industrial applications to non-invasively measure liquid and gas flow. Two transducers are oriented at a diagonal across a flow channel. Velocity measurement is accomplished by detecting slight variations in transit time of contra-propagating acoustic signals with a directional component parallel to air flow. Due to the symmetry of acoustic pathway between sensors, velocity measurements are immune to partial fouling in the tube from mucus, saliva, and condensation. A first generation proof of concept prototype was constructed to evaluate the ultrasonic TOF technique for medical tracheostomy monitoring. After successful performance, a second generation prototype was designed with a smaller form factor and more advanced electronics. This prototype was tested and found to measure inspired volume with a root-mean-square error < 2% during initial trials.

Generation and precise control of dynamic biochemical gradients for cellular assays

NASA Astrophysics Data System (ADS)

Saka, Yasushi; MacPherson, Murray; Giuraniuc, Claudiu V.

2017-03-01

Spatial gradients of diffusible signalling molecules play crucial roles in controlling diverse cellular behaviour such as cell differentiation, tissue patterning and chemotaxis. In this paper, we report the design and testing of a microfluidic device for diffusion-based gradient generation for cellular assays. A unique channel design of the device eliminates cross-flow between the source and sink channels, thereby stabilizing gradients by passive diffusion. The platform also enables quick and flexible control of chemical concentration that makes highly dynamic gradients in diffusion chambers. A model with the first approximation of diffusion and surface adsorption of molecules recapitulates the experimentally observed gradients. Budding yeast cells cultured in a gradient of a chemical inducer expressed a reporter fluorescence protein in a concentration-dependent manner. This microfluidic platform serves as a versatile prototype applicable to a broad range of biomedical investigations.

Repulsive force actuated rotary micromirror

NASA Astrophysics Data System (ADS)

He, Siyuan; Ben Mrad, Ridha

2004-09-01

In this paper, a novel repulsive force based rotary micromirror is proposed. A repulsive force is produced in the rotary micromirror and the mirror plate is pushed up and away from the substrate. Therefore the rotation angle of the micromirror is not limited to the space underneath the mirror plate and thus the "pull-in" effect is completely circumvented. The novel rotary micromirror can achieve a large rotation angle with a large mirror plate. In addition the novel micromirror has a very simple structure and can be fabricated by standard surface micromachining technology. Numerical simulation is used to verify the working principle of the novel micromirror. A prototype of the novel rotary micromirror is fabricated by a commercially available surface microfabrication process called MUMPs. The prototype has a mirror size of 300μm x 300μm. The experimental measurements show that the prototype can achieve a mechanical rotation of 2.25 degrees (an optical angle of 4.5 degrees) at a driving voltage of 170 volts. A conventional surface micromachined attractive force based rotary micromirror of the same size can only achieve an angle of 0.1~0.2 degree.

Design and Test of Advanced Thermal Simulators for an Alkali Metal-Cooled Reactor Simulator

NASA Technical Reports Server (NTRS)

Garber, Anne E.; Dickens, Ricky E.

2011-01-01

The Early Flight Fission Test Facility (EFF-TF) at NASA Marshall Space Flight Center (MSFC) has as one of its primary missions the development and testing of fission reactor simulators for space applications. A key component in these simulated reactors is the thermal simulator, designed to closely mimic the form and function of a nuclear fuel pin using electric heating. Continuing effort has been made to design simple, robust, inexpensive thermal simulators that closely match the steady-state and transient performance of a nuclear fuel pin. A series of these simulators have been designed, developed, fabricated and tested individually and in a number of simulated reactor systems at the EFF-TF. The purpose of the thermal simulators developed under the Fission Surface Power (FSP) task is to ensure that non-nuclear testing can be performed at sufficiently high fidelity to allow a cost-effective qualification and acceptance strategy to be used. Prototype thermal simulator design is founded on the baseline Fission Surface Power reactor design. Recent efforts have been focused on the design, fabrication and test of a prototype thermal simulator appropriate for use in the Technology Demonstration Unit (TDU). While designing the thermal simulators described in this paper, effort were made to improve the axial power profile matching of the thermal simulators. Simultaneously, a search was conducted for graphite materials with higher resistivities than had been employed in the past. The combination of these two efforts resulted in the creation of thermal simulators with power capacities of 2300-3300 W per unit. Six of these elements were installed in a simulated core and tested in the alkali metal-cooled Fission Surface Power Primary Test Circuit (FSP-PTC) at a variety of liquid metal flow rates and temperatures. This paper documents the design of the thermal simulators, test program, and test results.

A Prototype Bucket Wheel Excavator for the Moon, Mars and Phobos

NASA Astrophysics Data System (ADS)

Muff, T.; Johnson, L.; King, R.; Duke, M. B.

2004-02-01

Excavation of surface regolith material is the first step in processes to extract volatile materials from planetary surface regolith for the production of propellant and life support consumables. Typically, concentrations of volatiles are low, so relatively large amounts of material must be excavated. A bucket wheel excavator is proposed, which has the capability of continuous excavation, which is readily adapted to granular regolith materials as found on the Moon, in drift deposits on Mars, and probably on the surface of asteroids and satellites, such as Phobos. The bucket wheel excavator is relatively simple, compared to machines such as front end loaders. It also has the advantage that excavation forces are principally horizontal rather than vertical, which minimizes the need for excavator mass and suits it to operations in reduced gravity fields. A prototype small bucket wheel excavator has been built at approximately the scale of the rovers that are carried to Mars on the Mars Exploration Rover Mission. The prototype allows the collection of data on forces exerted and power requirements for excavation and will provide data on which more efficient designs can be based. At excavation rates in the vicinity of one rover mass of material excavated per hour, tests of the prototype demonstrate that the power required is largely that needed to operate the excavator hardware and not related strongly to the amount of material excavated. This suggests that the excavation rate can be much larger for the same excavation system mass. Work on this prototype is continuing on the details of transfer of material from the bucket wheel to an internal conveyor mechanism, which testing demonstrated to be problematic in the current design.

Experimental investigations of an endoluminal ultrasound applicator for MR-guided thermal therapy of pancreatic cancer

NASA Astrophysics Data System (ADS)

Adams, Matthew; Salgaonkar, Vasant; Jones, Peter; Plata, Juan; Chen, Henry; Pauly, Kim Butts; Sommer, Graham; Diederich, Chris

2017-03-01

An MR-guided endoluminal ultrasound applicator has been proposed for palliative and potential curative thermal therapy of pancreatic tumors. Minimally invasive ablation or hyperthermia treatment of pancreatic tumor tissue would be performed with the applicator positioned in the gastrointestinal (GI) lumen, and sparing of the luminal tissue would be achieved with a water-cooled balloon surrounding the ultrasound transducers. This approach offers the capability of conformal volumetric therapy for fast treatment times, with control over the 3D spatial deposition of energy. Prototype endoluminal ultrasound applicators have been fabricated using 3D printed fixtures that seat two 3.2 or 5.6 MHz planar or curvilinear transducers and contain channels for wiring and water flow. Spiral surface coils have been integrated onto the applicator body to allow for device localization and tracking for therapies performed under MR guidance. Heating experiments with a tissue-mimicking phantom in a 3T MR scanner were performed and demonstrated capability of the prototype to perform volumetric heating through duodenal luminal tissue under real-time PRF-based MR temperature imaging (MRTI). Additional experiments were performed in ex vivo pig carcasses with the applicator inserted into the esophagus and aimed towards liver or soft tissue surrounding the spine under MR guidance. These experiments verified the capacity of heating targets up to 20-25 mm from the GI tract. Active device tracking and automated prescription of imaging and temperature monitoring planes through the applicator were made possible by using Hadamard encoded tracking sequences to obtain the coordinates of the applicator tracking coils. The prototype applicators have been integrated with an MR software suite that performs real-time device tracking and temperature monitoring.

Experimental Pressure Measurements on Hydropower Turbine Runners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harding, Samuel F.; Richmond, Marshall C.

The range of hydrodynamic operating conditions to which the turbine is exposed results in significant pressure fluctuations on both the pressure and suction sides of the blades. Understanding these dynamic pressures has a range of applications. Structurally, the resulting dynamic loads are significant in understanding the design life and maintenance schedule of the bearing, shafts and runner components. The pulsing pressures have also been seen to have a detrimental effect on the surface condition of the blades. Biologically, the pressure gradients and pressure extremes are the primary driver of barotrauma for fish passing through hydroturbines. Improvements in computational fluid dynamicsmore » (CFD) can be used to simulate such unsteady pressures in the regions of concern. High frequency model scale and prototype measurements of pressures at the blade are important in the validation of these models. Experimental characterization of pressure fields over hydroturbine blades has been demonstrated by a number of studies which using multiple pressure transducers to map the pressure contours on the runner blades. These have been performed at both model and prototype scales, often to validate computational models of the pressure and flow fields over the blades. This report provides a review of existing studies in which the blade pressure was measured in situ. The report assesses the technology for both model and prototype scale testing. The details of the primary studies in this field are reported and used to inform the types of hardware required for similar experiments based on the Ice Harbor Dam owned by the US Corps of Engineers on the Snake River, WA, USA. Such a study would be used to validate the CFD performed for the BioPA.« less

Development of a compact, sealless, tripod supported, magnetically driven centrifugal blood pump.

PubMed

Yuhki, A; Nogawa, M; Takatani, S

2000-06-01

In this study, a tripod supported sealless centrifugal blood pump was designed and fabricated for implantable application using a specially designed DC brushless motor. The tripod structure consists of 3 ceramic balls mounted at the bottom surface of the impeller moving in a polyethylene groove incorporated at the bottom pump casing. The follower magnet inside the impeller is coupled to the driver magnet of the motor outside the bottom pump casing, thus allowing the impeller to slide-rotate in the polyethylene groove as the motor turns. The pump driver has a weight of 230 g and a diameter of 60 mm. The acrylic pump housing has a weight of 220 g with the priming volume of 25 ml. At the pump rpm of 1,000 to 2,200, the generated head pressure ranged from 30 to 150 mm Hg with the maximum system efficiency being 12%. When the prototype pump was used in the pulsatile mock loop to assist the ventricle from its apex to the aorta, a strong correlation was obtained between the motor current and bypass flow waveforms. The waveform deformation index (WDI), defined as the ratio of the fundamental to the higher order harmonics of the motor current power spectral density, was computed to possibly detect the suction occurring inside the ventricle due to the prototype centrifugal pump. When the WDI was kept under the value of 0.20 by adjusting the motor rpm, it was successful in suppressing the suction due to the centrifugal pump in the ventricle. The prototype sealless, centrifugal pump together with the control method based on the motor current waveform analysis may offer an intermediate support of the failing left or right ventricle bridging to heart transplantation.

Increased rate of solvent diffusion in a prototypical supramolecular gel measured on the picosecond timescale.

PubMed

Seydel, Tilo; Edkins, Robert M; Jones, Christopher D; Foster, Jonathan A; Bewley, Robert; Aguilar, Juan A; Edkins, Katharina

2018-06-14

Solvent diffusion in a prototypical supramolecular gel probed by quasi-elastic neutron scattering on the picosecond timescale is faster than that in the respective bulk solvent. This phenomenon is hypothesized to be due to disruption of the hydrogen bonding of the solvent by the large hydrophobic surface of the gel network.

Virtobot 2.0: the future of automated surface documentation and CT-guided needle placement in forensic medicine.

PubMed

Ebert, Lars Christian; Ptacek, Wolfgang; Breitbeck, Robert; Fürst, Martin; Kronreif, Gernot; Martinez, Rosa Maria; Thali, Michael; Flach, Patricia M

2014-06-01

In this paper we present the second prototype of a robotic system to be used in forensic medicine. The system is capable of performing automated surface documentation using photogrammetry, optical surface scanning and image-guided, post-mortem needle placement for tissue sampling, liquid sampling, or the placement of guide wires. The upgraded system includes workflow optimizations, an automatic tool-change mechanism, a new software module for trajectory planning and a fully automatic computed tomography-data-set registration algorithm. We tested the placement accuracy of the system by using a needle phantom with radiopaque markers as targets. The system is routinely used for surface documentation and resulted in 24 surface documentations over the course of 11 months. We performed accuracy tests for needle placement using a biopsy phantom, and the Virtobot placed introducer needles with an accuracy of 1.4 mm (±0.9 mm). The second prototype of the Virtobot system is an upgrade of the first prototype but mainly focuses on streamlining the workflow and increasing the level of automation and also has an easier user interface. These upgrades make the Virtobot a potentially valuable tool for case documentation in a scalpel-free setting that uses purely imaging techniques and minimally invasive procedures and is the next step toward the future of virtual autopsy.

Shielding Characteristics Using an Ultrasonic Configurable Fan Artificial Noise Source to Generate Modes - Experimental Measurements and Analytical Predictions

NASA Technical Reports Server (NTRS)

Sutliff, Daniel L.; Walker, Bruce E.

2014-01-01

An Ultrasonic Configurable Fan Artificial Noise Source (UCFANS) was designed, built, and tested in support of the NASA Langley Research Center's 14x22 wind tunnel test of the Hybrid Wing Body (HWB) full 3-D 5.8% scale model. The UCFANS is a 5.8% rapid prototype scale model of a high-bypass turbofan engine that can generate the tonal signature of proposed engines using artificial sources (no flow). The purpose of the program was to provide an estimate of the acoustic shielding benefits possible from mounting an engine on the upper surface of a wing; a flat plate model was used as the shielding surface. Simple analytical simulations were used to preview the radiation patterns - Fresnel knife-edge diffraction was coupled with a dense phased array of point sources to compute shielded and unshielded sound pressure distributions for potential test geometries and excitation modes. Contour plots of sound pressure levels, and integrated power levels, from nacelle alone and shielded configurations for both the experimental measurements and the analytical predictions are presented in this paper.

Development of an air flow thermal balance calorimeter

NASA Technical Reports Server (NTRS)

Sherfey, J. M.

1972-01-01

An air flow calorimeter, based on the idea of balancing an unknown rate of heat evolution with a known rate of heat evolution, was developed. Under restricted conditions, the prototype system is capable of measuring thermal wattages from 10 milliwatts to 1 watt, with an error no greater than 1 percent. Data were obtained which reveal system weaknesses and point to modifications which would effect significant improvements.

Spaceflight Flow Cytometry: Design Challenges and Applications

NASA Technical Reports Server (NTRS)

Pappas, Dimitri; Kao, Shih-Hsin; Jeevarajan, Antony S.

2004-01-01

Future space exploration missions will require analytical technology capable of providing both autonomous medical care to the crew and investigative capabilities to researchers. While several promising candidate technologies exist for further development, flow cytometry is an attractive technology as it offers both crew health and a wide array of biochemistry and immunology assays. While flow cytometry has been widely used for cellular analysis in both clinical and research settings, the requirements for proper operation in spaceflight impose constraints on any instrument designs. The challenges of designing a spaceflight-ready flow cytometer are discussed, as well as some preliminary results using a prototype system.

Lagrangian turbulence near walls: Structures and mixing in admissible model flows

NASA Astrophysics Data System (ADS)

Ottino, J. M.

1989-05-01

The general objective of work during this period was to bridge the gap between modern ideas from dynamical systems and chaos and more traditional approaches to turbulence. In order to reach this objective we conducted theoretical and computational work on two systems: a perturbed Kelvin cat eyes flow, and prototype solutions of the Navier-Stokes equations near solid walls. The main results obtained are two-fold: production flows capable of producing complex distributions of vorticity, and constructed flow fields, based on solutions of the Navier Stokes equations, which are capable of displaying both Eulerian and Lagrangian turbulence.

Steamer II: Steamer prototype component inventory and user interface commands. Technical report, 1988-1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dickieson, J.L.; Thode, W.F.; Newbury, K.

1988-12-01

Over the last several years, Navy Personnel Research and Development has produced a prototype simulation of a 1200-psi steam plant. This simulation, called Steamer, is installed on an expensive Symbolics minicomputer at the Surface Warfare Officers School, Pacific Coronado, California. The fundamental research goal of the Steamer prototype system was to evaluate the potential of, what was then, new artificial intelligence (AI) hardware and software technology for supporting the construction of computer-based training systems using graphic representations of complex, dynamic systems. The area of propulsion engineering was chosen for a number of reasons. This document describes the Steamer prototype systemmore » components and user interface commands and establishes a starting point for designing, developing, and implementing Steamer II. Careful examination of the actual program code produced an inventory that describes the hardware, system software, application software, and documentation for the Steamer prototype system. Exercising all menu options systematically produced an inventory of all Steamer prototype user interface commands.« less

Development of an air flow calorimeter prototype for the measurement of thermal power released by large radioactive waste packages.

PubMed

Razouk, R; Beaumont, O; Failleau, G; Hay, B; Plumeri, S

2018-03-01

The estimation and control of the thermal power released by the radioactive waste packages are a key parameter in the management of radioactive waste geological repository sites. In the framework of the European project "Metrology for decommissioning nuclear facilities," the French National Agency of Radioactive Waste Management (ANDRA) collaborates with Laboratoire National de Métrologie et D'essais in order to measure the thermal power up to 500 W of typical real size radioactive waste packages (of at least 0.175 m 3 ) with an uncertainty better than 5% by using a measurement method traceable to the international system of units. One of the selected metrological approaches is based on the principles of air flow calorimetry. This paper describes in detail the development of the air flow calorimeter prototype as well as the design of a radioactive waste package simulator used for its calibration. Results obtained from the calibration of the calorimeter and from the determination of thermal powers are presented here with an investigation of the measurement uncertainties.

Development of an air flow calorimeter prototype for the measurement of thermal power released by large radioactive waste packages

NASA Astrophysics Data System (ADS)

Razouk, R.; Beaumont, O.; Failleau, G.; Hay, B.; Plumeri, S.

2018-03-01

The estimation and control of the thermal power released by the radioactive waste packages are a key parameter in the management of radioactive waste geological repository sites. In the framework of the European project "Metrology for decommissioning nuclear facilities," the French National Agency of Radioactive Waste Management (ANDRA) collaborates with Laboratoire National de Métrologie et D'essais in order to measure the thermal power up to 500 W of typical real size radioactive waste packages (of at least 0.175 m3) with an uncertainty better than 5% by using a measurement method traceable to the international system of units. One of the selected metrological approaches is based on the principles of air flow calorimetry. This paper describes in detail the development of the air flow calorimeter prototype as well as the design of a radioactive waste package simulator used for its calibration. Results obtained from the calibration of the calorimeter and from the determination of thermal powers are presented here with an investigation of the measurement uncertainties.

Toward Real Time Neural Net Flight Controllers

NASA Technical Reports Server (NTRS)

Jorgensen, C. C.; Mah, R. W.; Ross, J.; Lu, Henry, Jr. (Technical Monitor)

1994-01-01

NASA Ames Research Center has an ongoing program in neural network control technology targeted toward real time flight demonstrations using a modified F-15 which permits direct inner loop control of actuators, rapid switching between alternative control designs, and substitutable processors. An important part of this program is the ACTIVE flight project which is examining the feasibility of using neural networks in the design, control, and system identification of new aircraft prototypes. This paper discusses two research applications initiated with this objective in mind: utilization of neural networks for wind tunnel aircraft model identification and rapid learning algorithms for on line reconfiguration and control. The first application involves the identification of aerodynamic flight characteristics from analysis of wind tunnel test data. This identification is important in the early stages of aircraft design because complete specification of control architecture's may not be possible even though concept models at varying scales are available for aerodynamic wind tunnel testing. Testing of this type is often a long and expensive process involving measurement of aircraft lift, drag, and moment of inertia at varying angles of attack and control surface configurations. This information in turn can be used in the design of the flight control systems by applying the derived lookup tables to generate piece wise linearized controllers. Thus, reduced costs in tunnel test times and the rapid transfer of wind tunnel insights into prototype controllers becomes an important factor in more efficient generation and testing of new flight systems. NASA Ames Research Center is successfully applying modular neural networks as one way of anticipating small scale aircraft model performances prior to testing, thus reducing the number of in tunnel test hours and potentially, the number of intermediate scaled models required for estimation of surface flow effects.

Study of Active Micromixer Driven by Electrothermal Force

NASA Astrophysics Data System (ADS)

Huang, Kuan-Rong; Chang, Jeng-Shian; Chao, Sheng D.; Wung, Tzong-Shyan; Wu, Kuang-Chong

2012-04-01

Biochemical applications of microchips often require a rapid mixing of different fluid samples. At the microscale level, fluid flow is usually a highly ordered laminar flow and diffusion is the primary mechanism for mixing owing to the lack of disturbances, yielding inefficiency for practical biochemical analysis. In this work, we design a prototype active micromixer by employing the electrothermal effect. We apply to the flow microchannel a non-uniform AC electric field, which can generate an electrothermal force on the fluid flow and induce vortex pairs for enhancing mixing efficiency. The performance of this active micromixer is studied and compared, under the same mixing quality, with that of a conventional passive micromixer of the same size with obstacles in the flow channel by three-dimensional finite element simulations. The numerical results show that the pressure drop between the inlet and the outlet for the active micromixer is much less than (only 3000th) that for the passive micro-mixer with the same mixing quality. To obtain an optimal mixing quality, we have systematically studied the mixing quality by varying the geometrical arrangements of the electrodes. An almost complete mixing can be obtained using a specific design. Moreover, the temperature increases around the electrodes are lower than 3 K, which does not adversely affect the biochemical analysis. It is suggested that the prototype active micromixer designed is promising and effective and useful for biochemical analysis.

The sustaining effect of three polymers on the release of chlorhexidine from a controlled release drug device for root canal disinfection.

PubMed

Lee, Doug-Youn; Spångberg, Larz S W; Bok, Young-Bin; Lee, Chang-Young; Kum, Kee-Yeon

2005-07-01

The aim of this in vitro study was to evaluate the suitability of using chitosan, poly (lactide-co-glycolide) (PLGA), and polymethyl methacrylate (PMMA) to control the release of chlorhexidine digluconate (CHX) from a prototype of controlled release drug device for root canal disinfection. Four different prototypes with different formulations were prepared. Group A (n = 12): the device (absorbent paper point) was loaded with CHX as control. Group B (n = 12): same as group A, but the device was coated with chitosan (Texan MedTech). In Groups C and D, the device was treated in the same way as group A and then coated 3 times with 5% PMMA (Group C, n = 12, Aldrich), or coated 3 times with 3% PLGA (Group D, n = 12, Sigma). The devices were randomly allocated to experimental groups of 12 each. All the prototypes of controlled release drug device were soaked in 3 mL distilled water. The concentrations of CHX were determined using a UV spectrophotometer. The surface characteristics of each prototype were observed using a scanning electron microscope. The result showed that release rate of CHX was the greatest in the noncoated group, followed by the chitosan-coated group, the PLGA-coated group, and the PMMA-coated group (P < 0.05). Pores were observed on the surface of the prototypes that were coated with PLGA and PMMA. When the pore size was smaller, the release rate was lower. These data indicate that polymer coating can control the release rate of CHX from the prototypes of controlled release drug device.

Automated payload experiment tool feasibility study

NASA Technical Reports Server (NTRS)

Maddux, Gary A.; Clark, James; Delugach, Harry; Hammons, Charles; Logan, Julie; Provancha, Anna

1991-01-01

To achieve an environment less dependent on the flow of paper, automated techniques of data storage and retrieval must be utilized. The prototype under development seeks to demonstrate the ability of a knowledge-based, hypertext computer system. This prototype is concerned with the logical links between two primary NASA support documents, the Science Requirements Document (SRD) and the Engineering Requirements Document (ERD). Once developed, the final system should have the ability to guide a principal investigator through the documentation process in a more timely and efficient manner, while supplying more accurate information to the NASA payload developer.

Interdisciplinary Development of an Improved Emergency Department Procedural Work Surface Through Iterative Design and Use Testing in Simulated and Clinical Environments.

PubMed

Zhang, Xiao C; Bermudez, Ana M; Reddy, Pranav M; Sarpatwari, Ravi R; Chheng, Darin B; Mezoian, Taylor J; Schwartz, Victoria R; Simmons, Quinneil J; Jay, Gregory D; Kobayashi, Leo

2017-03-01

A stable and readily accessible work surface for bedside medical procedures represents a valuable tool for acute care providers. In emergency department (ED) settings, the design and implementation of traditional Mayo stands and related surface devices often limit their availability, portability, and usability, which can lead to suboptimal clinical practice conditions that may affect the safe and effective performance of medical procedures and delivery of patient care. We designed and built a novel, open-source, portable, bedside procedural surface through an iterative development process with use testing in simulated and live clinical environments. The procedural surface development project was conducted between October 2014 and June 2016 at an academic referral hospital and its affiliated simulation facility. An interdisciplinary team of emergency physicians, mechanical engineers, medical students, and design students sought to construct a prototype bedside procedural surface out of off-the-shelf hardware during a collaborative university course on health care design. After determination of end-user needs and core design requirements, multiple prototypes were fabricated and iteratively modified, with early variants featuring undermattress stabilizing supports or ratcheting clamp mechanisms. Versions 1 through 4 underwent 2 hands-on usability-testing simulation sessions; version 5 was presented at a design critique held jointly by a panel of clinical and industrial design faculty for expert feedback. Responding to select feedback elements over several surface versions, investigators arrived at a near-final prototype design for fabrication and use testing in a live clinical setting. This experimental procedural surface (version 8) was constructed and then deployed for controlled usability testing against the standard Mayo stands in use at the study site ED. Clinical providers working in the ED who opted to participate in the study were provided with the prototype surface and just-in-time training on its use when performing bedside procedures. Subjects completed the validated 10-point System Usability Scale postshift for the surface that they had used. The study protocol was approved by the institutional review board. Multiple prototypes and recursive design revisions resulted in a fully functional, portable, and durable bedside procedural surface that featured a stainless steel tray and intuitive hook-and-lock mechanisms for attachment to ED stretcher bed rails. Forty-two control and 40 experimental group subjects participated and completed questionnaires. The median System Usability Scale score (out of 100; higher scores associated with better usability) was 72.5 (interquartile range [IQR] 51.3 to 86.3) for the Mayo stand; the experimental surface was scored at 93.8 (IQR 84.4 to 97.5 for a difference in medians of 17.5 (95% confidence interval 10 to 27.5). Subjects reported several usability challenges with the Mayo stand; the experimental surface was reviewed as easy to use, simple, and functional. In accordance with experimental live environment deployment, questionnaire responses, and end-user suggestions, the project team finalized the design specification for the experimental procedural surface for open dissemination. An iterative, interdisciplinary approach was used to generate, evaluate, revise, and finalize the design specification for a new procedural surface that met all core end-user requirements. The final surface design was evaluated favorably on a validated usability tool against Mayo stands when use tested in simulated and live clinical settings. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Graphical programming interface: A development environment for MRI methods.

PubMed

Zwart, Nicholas R; Pipe, James G

2015-11-01

To introduce a multiplatform, Python language-based, development environment called graphical programming interface for prototyping MRI techniques. The interface allows developers to interact with their scientific algorithm prototypes visually in an event-driven environment making tasks such as parameterization, algorithm testing, data manipulation, and visualization an integrated part of the work-flow. Algorithm developers extend the built-in functionality through simple code interfaces designed to facilitate rapid implementation. This article shows several examples of algorithms developed in graphical programming interface including the non-Cartesian MR reconstruction algorithms for PROPELLER and spiral as well as spin simulation and trajectory visualization of a FLORET example. The graphical programming interface framework is shown to be a versatile prototyping environment for developing numeric algorithms used in the latest MR techniques. © 2014 Wiley Periodicals, Inc.

[The design and experiment of multi-parameter water quality monitoring microsystem based on MOEMS microspectrometer].

PubMed

Wei, Kang-Lin; Wen, Zhi-Yu; Guo, Jian; Chen, Song-Bo

2012-07-01

Aiming at the monitoring and protecting of water resource environment, a multi-parameter water quality monitoring microsystem based on microspectrometer was put forward in the present paper. The microsystem is mainly composed of MOEMS microspectrometer, flow paths system and embedded measuring & controlling system. It has the functions of self-injecting samples and detection regents, automatic constant temperature, self -stirring, self- cleaning and samples' spectrum detection. The principle prototype machine of the microsystem was developed, and its structure principle was introduced in the paper. Through experiment research, it was proved that the principle prototype machine can rapidly detect quite a few water quality parameters and can meet the demands of on-line water quality monitoring, moreover, the principle prototype machine has strong function expansibility.

Performance of the first prototype of the CALICE scintillator strip electromagnetic calorimeter

NASA Astrophysics Data System (ADS)

Francis, K.; Repond, J.; Schlereth, J.; Smith, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S. T.; Sosebee, M.; White, A. P.; Yu, J.; Eigen, G.; Mikami, Y.; Watson, N. K.; Thomson, M. A.; Ward, D. R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Dotti, A.; Folger, G.; Ivantchenko, V.; Ribon, A.; Uzhinskiy, V.; Cârloganu, C.; Gay, P.; Manen, S.; Royer, L.; Tytgat, M.; Zaganidis, N.; Blazey, G. C.; Dyshkant, A.; Lima, J. G. R.; Zutshi, V.; Hostachy, J.-Y.; Morin, L.; Cornett, U.; David, D.; Ebrahimi, A.; Falley, G.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Karstensen, S.; Krivan, F.; Krüger, K.; Lutz, B.; Morozov, S.; Morgunov, V.; Neubüser, C.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Garutti, E.; Laurien, S.; Lu, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Briggl, K.; Eckert, P.; Harion, T.; Schultz-Coulon, H.-Ch.; Shen, W.; Stamen, R.; Bilki, B.; Norbeck, E.; Northacker, D.; Onel, Y.; Wilson, G. W.; Kawagoe, K.; Sudo, Y.; Yoshioka, T.; Dauncey, P. D.; Wing, M.; Salvatore, F.; Cortina Gil, E.; Mannai, S.; Baulieu, G.; Calabria, P.; Caponetto, L.; Combaret, C.; Della Negra, R.; Grenier, G.; Han, R.; Ianigro, J.-C.; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Vander Donckt, M.; Zoccarato, Y.; Calvo Alamillo, E.; Fouz, M.-C.; Puerta-Pelayo, J.; Corriveau, F.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Popov, V.; Rusinov, V.; Tarkovsky, E.; Besson, D.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Karakash, A.; Popova, E.; Tikhomirov, V.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Weuste, L.; Amjad, M. S.; Bonis, J.; Callier, S.; Conforti di Lorenzo, S.; Cornebise, P.; Doublet, Ph.; Dulucq, F.; Fleury, J.; Frisson, T.; van der Kolk, N.; Li, H.; Martin-Chassard, G.; Richard, F.; de la Taille, Ch.; Pöschl, R.; Raux, L.; Rouëné, J.; Seguin-Moreau, N.; Anduze, M.; Balagura, V.; Boudry, V.; Brient, J.-C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Guliyev, E.; Haddad, Y.; Magniette, F.; Musat, G.; Ruan, M.; Tran, T. H.; Videau, H.; Bulanek, B.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Kotera, K.; Ono, H.; Takeshita, T.; Uozumi, S.; Jeans, D.; Chang, S.; Khan, A.; Kim, D. H.; Kong, D. J.; Oh, Y. D.; Götze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.

2014-11-01

A first prototype of a scintillator strip-based electromagnetic calorimeter was built, consisting of 26 layers of tungsten absorber plates interleaved with planes of 45×10×3 mm3 plastic scintillator strips. Data were collected using a positron test beam at DESY with momenta between 1 and 6 GeV/c. The prototype's performance is presented in terms of the linearity and resolution of the energy measurement. These results represent an important milestone in the development of highly granular calorimeters using scintillator strip technology. A number of possible design improvements were identified, which should be implemented in a future detector of this type. This technology is being developed for a future linear collider experiment, aiming at the precise measurement of jet energies using particle flow techniques.

The rate of rise, fall and gravity spreading at Siahou diapir (Southern Iran)

NASA Astrophysics Data System (ADS)

Aftabi, P.; Roustaie, M.

2009-04-01

InSAR imaging can be used for extracting three dimensional information of the diapirs surface by using the phase part of the radar signal. We used InSAR to examine the cumulative surface deformation between 920706 to 060518, in a 10×10 km region surrounding the salt diapir at Kuh-e-Namak Siahou. The interferograms span periods was between 35-70 and 1248 days. Images acquired in 12 increments provided by ESA. This technique used here involves computation and subsequent combinations of interferometric phase gradient maps were used for mapping the salt flow deformation in the Zagros. Kuh-e-Namak Siahou is one of the salt extrusions currently active in the Zagros range in Iran. Salt rises from a mother salt horizon about 4 km deep and extruded as a dome with glacier on the surface. The geometry and inferred flow pattern of the salt changed between the increments, emphasizing that the extrusion rate and gravity spreading is not steady. Elevations in the salt mountain range from 1000 to 1640 meters and the displacements exceed to 20cm per year . Our InSAR study(Fig1) suggest that the dimensions and velocity of the salt movements are changing between 2 to 20mm per year(-0.7 to0.59 mm per day).The rate of surface dissolution changed between 2 to 4 cm a-1, and its rate of rise out of its orifice at 0 to 200 mm per year. The InSAR study suggest that the vigorous salt extrusion in Siahou is probably active.The deep source probably rise at a similar rates in the past but it fall in the time of InSAR study. The rate of fall was 260 mm per year(for 14 years). The InSAR images suggest that salt extrusion in Siahou flow laterally at rate 20-25 mm per year and the namakiers felt at -2 mm per month. The InSAR results indicated concentric and radial flow in the diapir from a central point at summit and spreading glaciers in sideways.Phase differences measured in our interferograms generally in the range of 0-260 mm/yr(-260 mm) within the studied period, with exceptional high rates that exceed 50 mm/yr in diapir Siahou. Comparison of our InSAR observations with models suggest a similarity in the strain pattern in the model and prototype. Our observations also show that in certain locations of Zagros, movements appear to be structurally controlled by salt flow, and diapirism. This report will improve our understanding on how the salt diapirs work and our capability to predict future flow and the associated hazards for storages in salt and provides the first direct, spatially resolved, measurement of ongoing flow of salt. Key words: Salt tectonics,InSAR,Monitoring,Iran,Zagros,Salt diapir,salt kinematics, Zagros fold-thrust belt, Hormuz salt, analogue modelling,salt extrusion, crustal shortening

Report on dynamic speed harmonization and queue warning algorithm design.

DOT National Transportation Integrated Search

2014-02-01

This report provides a detailed description of the algorithms that will be used to generate harmonized recommended speeds and queue warning information in the proposed Intelligent Network Flow Optimization (INFLO) prototype. This document describes t...

Data Flow System operations: from the NTT to the VLT

NASA Astrophysics Data System (ADS)

Silva, David R.; Leibundgut, Bruno; Quinn, Peter J.; Spyromilio, Jason; Tarenghi, Massimo

1998-07-01

Science operations at the ESO very large telescope is scheduled to begin in April 1999. ESO is currently finalizing the VLT science operations plan. This plan describes the operations tasks and staffing needed to support both visitor and service mode operations. The Data Flow Systems (DFS) currently being developed by ESO will provide the infrastructure necessary for VLT science operations. This paper describes the current VLT science operations plan, first by discussing the tasks involved and then by describing the operations teams that have responsibility for those tasks. Prototypes of many of these operational concepts and tools have been in use at the ESO New Technology Telescope (NTT) since February 1997. This paper briefly summarizes the status of these prototypes and then discusses what operation lessons have been learned from the NTT experience and how they can be applied to the VLT.

A prototype for automation of land-cover products from Landsat Surface Reflectance Data Records

NASA Astrophysics Data System (ADS)

Rover, J.; Goldhaber, M. B.; Steinwand, D.; Nelson, K.; Coan, M.; Wylie, B. K.; Dahal, D.; Wika, S.; Quenzer, R.

2014-12-01

Landsat data records of surface reflectance provide a three-decade history of land surface processes. Due to the vast number of these archived records, development of innovative approaches for automated data mining and information retrieval were necessary. Recently, we created a prototype utilizing open source software libraries for automatically generating annual Anderson Level 1 land cover maps and information products from data acquired by the Landsat Mission for the years 1984 to 2013. The automated prototype was applied to two target areas in northwestern and east-central North Dakota, USA. The approach required the National Land Cover Database (NLCD) and two user-input target acquisition year-days. The Landsat archive was mined for scenes acquired within a 100-day window surrounding these target dates, and then cloud-free pixels where chosen closest to the specified target acquisition dates. The selected pixels were then composited before completing an unsupervised classification using the NLCD. Pixels unchanged in pairs of the NLCD were used for training decision tree models in an iterative process refined with model confidence measures. The decision tree models were applied to the Landsat composites to generate a yearly land cover map and related information products. Results for the target areas captured changes associated with the recent expansion of oil shale production and agriculture driven by economics and policy, such as the increase in biofuel production and reduction in Conservation Reserve Program. Changes in agriculture, grasslands, and surface water reflect the local hydrological conditions that occurred during the 29-year span. Future enhancements considered for this prototype include a web-based client, ancillary spatial datasets, trends and clustering algorithms, and the forecasting of future land cover.

Ghana watershed prototype products

USGS Publications Warehouse

,

2007-01-01

A number of satellite data sets are available through the U.S. Geological Survey (USGS) for monitoring land surface features. Representative data sets include Landsat, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and Shuttle Radar Topography Mission (SRTM). The Ghana Watershed Prototype Products cover an area within southern Ghana, Africa, and include examples of the aforementioned data sets along with sample SRTM derivative data sets.

Prototyping phase of the high heat flux scraper element of Wendelstein 7-X

DOE PAGES

Boscary, Jean; Greuner, Henri; Ehrke, G.; ...

2016-03-24

The water-cooled high heat flux scraper element aims to reduce excessive heat loads on the target element ends of the actively cooled divertor of Wendelstein 7-X. Its purpose is to intercept some of the plasma fluxes both upstream and downstream before they reach the divertor surface. The scraper element has 24 identical plasma facing components (PFCs) divided into 6 modules. One module has 4 PFCs hydraulically connected in series by 2 water boxes. A PFC, 247 mm long and 28 mm wide, has 13 monoblocks made of CFC NB31 bonded by hot isostatic pressing onto a CuCrZr cooling tube equippedmore » with a copper twisted tape. 4 full-scale prototypes of PFCs have been successfully tested in the GLADIS facility up to 20 MW/m 2. The difference observed between measured and calculated surface temperatures is probably due to the inhomogeneity of CFC properties. The design of the water box prototypes has been detailed to allow the junction between the cooling pipe of the PFCs and the water boxes by internal orbital welding. In conclusion, the prototypes are presently under fabrication.« less

Web-Based Predictive Analytics to Improve Patient Flow in the Emergency Department

NASA Technical Reports Server (NTRS)

Buckler, David L.

2012-01-01

The Emergency Department (ED) simulation project was established to demonstrate how requirements-driven analysis and process simulation can help improve the quality of patient care for the Veterans Health Administration's (VHA) Veterans Affairs Medical Centers (VAMC). This project developed a web-based simulation prototype of patient flow in EDs, validated the performance of the simulation against operational data, and documented IT requirements for the ED simulation.

Flipperons for Improved Aerodynamic Performance

NASA Technical Reports Server (NTRS)

Mabe, James H.

2008-01-01

Lightweight, piezoelectrically actuated bending flight-control surfaces have shown promise as means of actively controlling airflows to improve the performances of transport airplanes. These bending flight-control surfaces are called flipperons because they look somewhat like small ailerons, but, unlike ailerons, are operated in an oscillatory mode reminiscent of the actions of biological flippers. The underlying concept of using flipperons and other flipperlike actuators to impart desired characteristics to flows is not new. Moreover, elements of flipperon-based active flow-control (AFC) systems for aircraft had been developed previously, but it was not until the development reported here that the elements have been integrated into a complete, controllable prototype AFC system for wind-tunnel testing to enable evaluation of the benefits of AFC for aircraft. The piezoelectric actuator materials chosen for use in the flipperons are single- crystal solid solutions of lead zinc niobate and lead titanate, denoted generically by the empirical formula (1-x)[Pb(Zn(1/3)Nb(2/3))O3]:x[PbTiO3] (where x<1) and popularly denoted by the abbreviation PZN-PT. These are relatively newly recognized piezoelectric materials that are capable of strain levels exceeding 1 percent and strain-energy densities 5 times greater than those of previously commercially available piezoelectric materials. Despite their high performance levels, (1-x)[Pb(Zn(1/3)Nb(2/3))O3]:x[PbTiO3] materials have found limited use until now because, relative to previously commercially available piezoelectric materials, they tend to be much more fragile.

Plasma flow measurements in the Prototype-Material Plasma Exposure eXperiment (Proto-MPEX) and comparison with B2.5-Eirene modeling

NASA Astrophysics Data System (ADS)

Kafle, N.; Owen, L. W.; Caneses, J. F.; Biewer, T. M.; Caughman, J. B. O.; Donovan, D. C.; Goulding, R. H.; Rapp, J.

2018-05-01

The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) at Oak Ridge National Laboratory is a linear plasma device that combines a helicon plasma source with additional microwave and radio frequency heating to deliver high plasma heat and particle fluxes to a target. Double Langmuir probes and Thomson scattering are being used to measure local electron temperature and density at various radial and axial locations. A recently constructed Mach-double probe provides the added capability of simultaneously measuring electron temperatures ( T e), electron densities ( n e), and Mach numbers (M). With this diagnostic, it is possible to infer the plasma flow, particle flux, and heat flux at different locations along the plasma column in Proto-MPEX. Preliminary results show Mach numbers of 0.5 (towards the dump plate) and 1.0 (towards the target plate) downstream from the helicon source, and a stagnation point (no flow) near the source for the case where the peak magnetic field was 1.3 T. Measurements of particle flow and ne and Te profiles are discussed. The extensive coverage provided by these diagnostics permits data-constrained B2.5-Eirene modeling of the entire plasma column, and comparison with results of modeling in the high-density helicon plasmas will be presented.

Prototype Systems for Measuring Outdoor Air Intake Rates in Rooftop Air Handlers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fisk, William J.; Chan, Wanyu R.; Hotchi, Toshifumi

2015-01-01

The widespread absence of systems for real-time measurement and feedback control, of minimum outdoor air intake rates in HVAC systems contributes to the poor control of ventilation rates in commercial buildings. Ventilation rates affect building energy consumption and influence occupant health. The project designed fabricated and tested four prototypes of systems for measuring rates of outdoor air intake into roof top air handlers. All prototypes met the ±20% accuracy target at low wind speeds, with all prototypes accurate within approximately ±10% after application of calibration equations. One prototype met the accuracy target without a calibration. With two of four prototypemore » measurement systems, there was no evidence that wind speed or direction affected accuracy; however, winds speeds were generally below usually 3.5 m s -1 (12.6 km h -1) and further testing is desirable. The airflow resistance of the prototypes was generally less than 35 Pa at maximum RTU air flow rates. A pressure drop of this magnitude will increase fan energy consumption by approximately 4%. The project did not have resources necessary to estimate costs of mass produced systems. The retail cost of components and materials used to construct prototypes ranged from approximately $1,200 to $1,700. The test data indicate that the basic designs developed in this project, particularly the designs of two of the prototypes, have considerable merit. Further design refinement, testing, and cost analysis would be necessary to fully assess commercial potential. The designs and test results will be communicated to the HVAC manufacturing community.« less

Design considerations for a space-borne ocean surface laser altimeter

NASA Technical Reports Server (NTRS)

Plotkin, H. H.

1972-01-01

Design procedures for using laser ranging systems in spacecraft to reflect ocean surface pulses vertically and measure spacecraft altitude with high precision are examined. Operating principles and performance experience of a prototype system are given.

Development of model-based control for Bridgman crystal growth

NASA Astrophysics Data System (ADS)

Sonda, Paul; Yeckel, Andrew; Daoutidis, Prodromos; Derby, Jeffrey. J.

2004-05-01

We study the feasibility of using crucible rotation with feedback control to suppress oscillatory flows in two prototypical vertical Bridgman crystal growth systems—a stabilizing configuration driven by a time-oscillatory furnace disturbance and a thermally destabilized configuration, which exhibits inherent time-varying flows. Proportional controllers are applied to the two systems, with volume-averaged flow speed chosen as the single controlled output and crucible rotation chosen as the manipulated input. Proportional control is able to significantly suppress oscillations in the stabilizing configuration. For the destabilized case, control is effective for small-amplitude flows but is generally ineffective, due to the exacerbating effect of crucible rotation on the time-dependent flows exhibited by this system.

Design and Prototyping of a High Granularity Scintillator Calorimeter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zutshi, Vishnu

A novel approach for constructing fine-granularity scintillator calorimeters, based on the concept of an Integrated Readout Layer (IRL) was developed. The IRL consists of a printed circuit board inside the detector which supports the directly-coupled scintillator tiles, connects to the surface-mount SiPMs and carries the necessary front-end electronics and signal/bias traces. Prototype IRLs using this concept were designed, prototyped and successfully exposed to test beams. Concepts and implementations of an IRL carried out with funds associated with this contract promise to result in the next generation of scintillator calorimeters.

Modeling granular material flows: The angle of repose, fluidization and the cliff collapse problem

NASA Astrophysics Data System (ADS)

Holsapple, Keith A.

2013-07-01

I discuss theories of granular material flows, with application to granular flows on the earth and planets. There are two goals. First, there is a lingering belief of some that the standard continuum plasticity Mohr-Coulomb and/or Drucker-Prager models are not adequate for many large-scale granular flow problems. The stated reason for those beliefs is the fact that the final slopes of the run-outs in collapse, landslide problems, and large-scale cratering are well below the angle of repose of the material. That observation, combined with the supposition that in those models flow cannot occur with slopes less than the angle of repose, has led to a number of researchers suggesting a need for lubrication or fluidization mechanisms and modeling. That issue is investigated in detail and shown to be false. A complete analysis of slope failures according to the Mohr-Coulomb model is presented, with special attention to the relations between the angle of repose and slope failures. It is shown that slope failure can occur for slope angles both larger than and smaller than the angle of repose. Second, to study the details of landslide run-outs, finite-difference continuum code simulations of the prototypical cliff collapse problem, using the classical plasticity models, are presented, analyzed and compared to experiments. Although devoid of any additional fluidization models, those simulations match experiments in the literature extremely well. The dynamics of this problem introduces additional important features relating to the run-out and final slope angles. The vertical free surface begins to fall at the initial 90° and flow continues to a final slope less than 10°. The detail in the calculation is examined to show why flow persists at slope angles that appear to be less than the angle of repose. The motions include regions of solid-like, fluid-like, and gas-like flows without invoking any additional models.

Investigation of Injector Slot Geometry on Curved-Diffuser Aerodynamic Performance

NASA Technical Reports Server (NTRS)

Silva, Odlanier

2004-01-01

The Compressor Branch vision is to be recognized as world-class leaders in research for fluid mechanics of compressors. Its mission is to conduct research and develop technology to advance the state of the art of compressors and transfer new technology to U.S. industries. Maintain partnerships with U.S. industries, universities, and other government organizations. Maintain a balance between customers focused and long range research. Flow control comprises enabling technologies to meet compression system performance requirements driven by emissions and fuel reduction goals (e.g., in UEET), missions (e.g., access-to-space), aerodynamically aggressive vehicle configurations (e.g., UAV and future blended wing body configurations with highly distorted inlets), and cost goals (e.g., in VAATE). The compression system requirements include increased efficiency, power-to-weight, and adaptability (i.e., robustness in terms of wide operability, distortion tolerance, and engine system health and reliability). The compressor flow control task comprises efforts to develop, demonstrate, and transfer adaptive flow control technology to industry to increase aerodynamic loading at current blade row loss levels, to enable adaptive1 y wide operability, and to develop plant models for adaptive compression systems. In this context, flow control is the controlled modification of a flow field by a deliberate means beyond the natural (uncontrolled) shaping of the solid surfaces that define the principal flow path. The objective of the compressor flow control task is to develop and apply techniques that control circulation, aerodynamic blockage, and entropy production in order to enhance the performance and operability of compression systems for advanced aero-propulsion applications. This summer I would be working with a curved-diffuser because it simulates what happens with flow in the stator blades in the compressor. With this experiment I will be doing some data analysis and parametric study of the injector slot geometries to get the best aerodynamic performance of it. This includes some data reduction, redesign and fast prototyping of the injector nozzle.

DIFFEOMORPHIC SURFACE FLOWS: A NOVEL METHOD OF SURFACE EVOLUTION*

PubMed Central

Zhang, Sirong; Younes, Laurent; Zweck, John; Ratnanather, J. Tilak

2009-01-01

We describe a new class of surface flows, diffeomorphic surface flows, induced by restricting diffeomorphic flows of the ambient Euclidean space to a surface. Different from classical surface PDE flows such as mean curvature flow, diffeomorphic surface flows are solutions of integro-differential equations in a group of diffeomorphisms. They have the potential advantage of being both topology-invariant and singularity free, which can be useful in computational anatomy and computer graphics. We first derive the Euler–Lagrange equation of the elastic energy for general diffeomorphic surface flows, which can be regarded as a smoothed version of the corresponding classical surface flows. Then we focus on diffeomorphic mean curvature flow. We prove the short-time existence and uniqueness of the flow, and study the long-time existence of the flow for surfaces of revolution. We present numerical experiments on synthetic and cortical surfaces from neuroimaging studies in schizophrenia and auditory disorders. Finally we discuss unresolved issues and potential applications. PMID:20016768

An Earth-Based Equivalent Low Stretch Apparatus to Assess Material Flammability for Microgravity and Extraterrestrial Fire-Safety Applications

NASA Technical Reports Server (NTRS)

Olson, S. L.; Beeson, H.; Haas, J. P.

2003-01-01

The objective of this project is to modify the standard oxygen consumption (cone) calorimeter (described in ASTM E 1354 and NASA STD 6001 Test 2) to provide a reproducible bench-scale test environment that simulates the buoyant or ventilation flow that would be generated by or around a burning surface in a spacecraft or extraterrestrial gravity level. This apparatus will allow us to conduct normal gravity experiments that accurately and quantitatively evaluate a material's flammability characteristics in the real-use environment of spacecraft or extra-terrestrial gravitational acceleration. The Equivalent Low Stretch Apparatus (ELSA) uses an inverted cone geometry with the sample burning in a ceiling fire configuration that provides a reproducible bench-scale test environment that simulates the buoyant or ventilation flow that would be generated by a flame in a spacecraft or extraterrestrial gravity level. Prototype unit testing results are presented in this paper. Ignition delay times and regression rates for PMMA are presented over a range of radiant heat flux levels and equivalent stretch rates which demonstrate the ability of ELSA to simulate key features of microgravity and extraterrestrial fire behavior.

A Self-Circulating Heat Exchanger for Use in Stirling and Thermoacoustic-Stirling Engines

NASA Astrophysics Data System (ADS)

Backhaus, Scott; Reid, Robert S.

2005-02-01

A major technical hurdle to the implementation of large Stirling engines or thermoacoustic engines is the reliability, performance, and manufacturability of the hot heat exchanger that brings high-temperature heat into the engine. Unlike power conversion devices that utilize steady flow, the oscillatory nature of the flow in Stirling and thermoacoustic engines restricts the length of a traditional hot heat exchanger to a peak-to-peak gas displacement, which is usually around 0.2 meters or less. To overcome this restriction, a new hot heat exchanger has been devised that uses a fluid diode in a looped pipe, which is resonantly driven by the oscillating gas pressure in the engine itself, to circulate the engine's working fluid around the loop. Instead of thousands of short, intricately interwoven passages that must be individually sealed, this new design consists of a few pipes that are typically 10 meters long. This revolutionary approach eliminates thousands of hermetic joints, pumps the engine's working fluid to and from a remote heat source without using moving parts, and does so without compromising on heat transfer surface area. Test data on a prototype loop integrated with a 1-kW thermoacoustic engine will be presented.

Integrated environmental monitoring and simulation system for use as a management decision support tool in urban areas.

PubMed

Fatta, D; Naoum, D; Loizidou, M

2002-04-01

Leachates are generated as a result of water or other liquid passing through waste at a landfill site. These contaminated liquids originate from a number of sources, including the water produced during the decomposition of the waste as well as rain-fall which penetrates the waste and dissolves the material with which it comes into contact. The penetration of the rain-water depends on the nature of the landfill (e.g. surface characteristics, type and quantity of vegetation, gradient of layers, etc). The uncontrolled infiltration of leachate into the vadose (unsaturated) zone and finally into the saturated zone (groundwater) is considered to be the most serious environmental impact of a landfill. In the present paper the water flow and the pollutant transport characteristics of the Ano Liosia Landfill site in Athens (Greece) were simulated by creating a model of groundwater flows and contaminant transport. A methodology for the model is presented. The model was then integrated into the Ecosim system which is a prototype funded by the EU, (Directorate General XIII: Telematics and Environment). This is an integrated environmental monitoring and modeling system, which supports the management of environmental planning in urban areas.

Fabrication of phonon-based metamaterial structures using focused ion beam patterning

NASA Astrophysics Data System (ADS)

Bassim, Nabil D.; Giles, Alexander J.; Ocola, Leonidas E.; Caldwell, Joshua D.

2018-02-01

The focused ion beam (FIB) is a powerful tool for rapid prototyping and machining of functional nanodevices. It is employed regularly to fabricate test metamaterial structures but, to date, has been unsuccessful in fabricating metamaterial structures with features at the nanoscale that rely on surface phonons as opposed to surface plasmons because of the crystalline damage that occurs with the collision cascade associated with ion sputtering. In this study, we employ a simple technique of protecting the crystalline substrate in single-crystal 4H-SiC to design surface phonon polariton-based optical resonance structures. By coating the material surface with a thin film of chromium, we have placed a material of high sputter resistance on the surface, which essentially absorbs the energy in the beam tails. When the beam ultimately punches through the Cr film, the hard walls in the film have the effect of channeling the beam to create smooth sidewalls. This demonstration opens the possibility of further rapid-prototyping of metamaterials using FIB.

Prototype Vent Gas Heat Exchanger for Exploration EVA - Performance and Manufacturing Characteristics

NASA Technical Reports Server (NTRS)

Jennings, Mallory; Quinn, Gregory; Strange, Jeremy

2012-01-01

NASA is developing new portable life support system (PLSS) technologies, which it is demonstrating in an unmanned ground based prototype unit called PLSS 2.0. One set of technologies within the PLSS provides suitable ventilation to an astronaut while on an EVA. A new component within the ventilation gas loop is a liquid-to-gas heat exchanger to transfer excess heat from the gas to the thermal control system's liquid coolant loop. A unique bench top prototype heat exchanger was built and tested for use in PLSS 2.0. The heat exchanger was designed as a counter-flow, compact plate fin type using stainless steel. Its design was based on previous compact heat exchangers manufactured by United Technologies Aerospace Systems, but was half the size of any previous heat exchanger model and one third the size of previous liquid-to-gas heat exchangers. The prototype heat exchanger was less than 40 cubic inches and weighed 2.6 lb. The water side and gas side pressure drops were 0.8 psid and 0.5 inches of water, respectively. Performance of the heat exchanger at the nominal pressure of 4.1 psia was measured at 94%, while a gas inlet pressure of 25 psia resulted in an effectiveness of 84%. These results compared well with the model, which was scaled for the small size. Modeling of certain phenomena that affect performance, such as flow distribution in the headers was particularly difficult due to the small size of the heat exchanger. Data from the tests has confirmed the correction factors that were used in these parts of the model.

Airport Information Retrieval System (AIRS) User's Guide

DOT National Transportation Integrated Search

1973-08-01

The handbook is a user's guide for a prototype air traffic flow control automation system developed for the FAA's System Command Center. The system is implemented on a time-sharing computer and is designed to provide airport traffic load predictions ...

Airport Information Retrieval System (AIRS) System Support Manual

DOT National Transportation Integrated Search

1973-01-01

This handbook is a support manual for prototype air traffic flow control automation system developed for the FAA's Systems Command Center. The system is implemented on a time-sharing computer and is designed to provide airport traffic load prediction...

Airport Information Retrieval System (AIRS) System Design

DOT National Transportation Integrated Search

1974-07-01

This report presents the system design for a prototype air traffic flow control automation system developed for the FAA's Systems Command Center. The design was directed toward the immediate automation of airport data for use in traffic load predicti...

Unsteady flow motions in the supraglottal region during phonation

NASA Astrophysics Data System (ADS)

Luo, Haoxiang; Dai, Hu

2008-11-01

The highly unsteady flow motions in the larynx are not only responsible for producing the fundamental frequency tone in phonation, but also have a significant contribution to the broadband noise in the human voice. In this work, the laryngeal flow is modeled either as an incompressible pulsatile jet confined in a two-dimensional channel, or a pressure-driven flow modulated by a pair of viscoelastic vocal folds through the flow--structure interaction. The flow in the supraglottal region is found to be dominated by large-scale vortices whose unsteady motions significantly deflect the glottal jet. In the flow--structure interaction, a hybrid model based on the immersed-boundary method is developed to simulate the flow-induced vocal fold vibration, which involves a three-dimensional vocal fold prototype and a two-dimensional viscous flow. Both the flow behavior and the vibratory characteristics of the vocal folds will be presented.

Development of an active boring bar for increased chatter immunity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Redmond, J.; Barney, P.; Smith, D.

The development and initial evaluation of a prototype boring bar featuring active vibration control for increased chatter immunity is described. The significance of active damping both normal and tangential to the workpiece surface is evaluated, indicating the need for two axis control to ensure adequate performance over expected variations in tool mounting procedures. The prototype tool features a commercially available boring bar modified to accommodate four PZT stack actuators for two axis bending control. Measured closed-loop dynamics are combined with a computer model of the boring process to simulate increased metal removal rate and improved workpiece surface finish through activemore » control.« less

[Surface coils for magnetic-resonance images].

PubMed

Rodríguez-González, Alfredo Odón; Amador-Baheza, Ricardo; Rojas-Jasso, Rafael; Barrios-Alvarez, Fernando Alejandro

2005-01-01

Since the introduction of magnetic resonance imaging in Mexico, the development of this important medical imaging technology has been almost non-existing in our country. The very first surface coil prototypes for clinical applications in magnetic resonance imaging has been developed at the Center of Research in Medical Imaging and Instrumentation of the Universidad Autónoma Metropolitana Iztapalapa (Metropolitan Autonomous University, Campus Iztapalapa). Two surface coil prototypes were built: a) a circular-shaped coil and b) a square-shaped coil for multiple regions of the body, such as heart, brain, knee, hands, and ankles. These coils were tested on the 1.5T imager of the ABC Hospital-Tacubaya, located in Mexico City. Brain images of healthy volunteers were obtained in different orientations: sagittal, coronal, and axial. Since images showed a good-enough clinical quality for diagnosis, it is fair to say that these coil prototypes can be used in the clinical environment, and with small modifications, they can be made compatible with almost any commercial scanner. This type of development can offer new alternatives for further collaboration between the research centers and the radiology community, in the search of new applications and developments of this imaging technique.

An Autonomous Sensor System Architecture for Active Flow and Noise Control Feedback

NASA Technical Reports Server (NTRS)

Humphreys, William M, Jr.; Culliton, William G.

2008-01-01

Multi-channel sensor fusion represents a powerful technique to simply and efficiently extract information from complex phenomena. While the technique has traditionally been used for military target tracking and situational awareness, a study has been successfully completed that demonstrates that sensor fusion can be applied equally well to aerodynamic applications. A prototype autonomous hardware processor was successfully designed and used to detect in real-time the two-dimensional flow reattachment location generated by a simple separated-flow wind tunnel model. The success of this demonstration illustrates the feasibility of using autonomous sensor processing architectures to enhance flow control feedback signal generation.

A numerical performance assessment of a commercial cardiopulmonary by-pass blood heat exchanger.

PubMed

Consolo, Filippo; Fiore, Gianfranco B; Pelosi, Alessandra; Reggiani, Stefano; Redaelli, Alberto

2015-06-01

We developed a numerical model, based on multi-physics computational fluid dynamics (CFD) simulations, to assist the design process of a plastic hollow-fiber bundle blood heat exchanger (BHE) integrated within the INSPIRE(TM), a blood oxygenator (OXY) for cardiopulmonary by-pass procedures, recently released by Sorin Group Italia. In a comparative study, we analyzed five different geometrical design solutions of the BHE module. Quantitative geometrical-dependent parameters providing a comprehensive evaluation of both the hemo- and thermo-dynamics performance of the device were extracted to identify the best-performing prototypical solution. A convenient design configuration was identified, characterized by (i) a uniform blood flow pattern within the fiber bundle, preventing blood flow shunting and the onset of stagnation/recirculation areas and/or high velocity pathways, (ii) an enhanced blood heating efficiency, and (iii) a reduced blood pressure drop. The selected design configuration was then prototyped and tested to experimentally characterize the device performance. Experimental results confirmed numerical predictions, proving the effectiveness of CFD modeling as a reliable tool for in silico identification of suitable working conditions of blood handling medical devices. Notably, the numerical approach limited the need for extensive prototyping, thus reducing the corresponding machinery costs and time-to-market. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Process-Structure-Property Relationships for 316L Stainless Steel Fabricated by Additive Manufacturing and Its Implication for Component Engineering

NASA Astrophysics Data System (ADS)

Yang, Nancy; Yee, J.; Zheng, B.; Gaiser, K.; Reynolds, T.; Clemon, L.; Lu, W. Y.; Schoenung, J. M.; Lavernia, E. J.

2017-04-01

We investigate the process-structure-property relationships for 316L stainless steel prototyping utilizing 3-D laser engineered net shaping (LENS), a commercial direct energy deposition additive manufacturing process. The study concluded that the resultant physical metallurgy of 3-D LENS 316L prototypes is dictated by the interactive metallurgical reactions, during instantaneous powder feeding/melting, molten metal flow and liquid metal solidification. The study also showed 3-D LENS manufacturing is capable of building high strength and ductile 316L prototypes due to its fine cellular spacing from fast solidification cooling, and the well-fused epitaxial interfaces at metal flow trails and interpass boundaries. However, without further LENS process control and optimization, the deposits are vulnerable to localized hardness variation attributed to heterogeneous microstructure, i.e., the interpass heat-affected zone (HAZ) from repetitive thermal heating during successive layer depositions. Most significantly, the current deposits exhibit anisotropic tensile behavior, i.e., lower strain and/or premature interpass delamination parallel to build direction (axial). This anisotropic behavior is attributed to the presence of interpass HAZ, which coexists with flying feedstock inclusions and porosity from incomplete molten metal fusion. The current observations and findings contribute to the scientific basis for future process control and optimization necessary for material property control and defect mitigation.

Stability of reference masses: VII. Cleaning methods in air and vacuum applied to a platinum mass standard similar to the international and national kilogram prototypes

NASA Astrophysics Data System (ADS)

Cumpson, Peter J.; Sano, Naoko; Barlow, Anders J.; Portoles, Jose F.

2013-10-01

Mercury contamination and the build-up of carbonaceous contamination are two contributing factors to the instability observed in kilogram prototype masses. The kilogram prototypes that lie at the core of the dissemination of the SI base unit were manufactured in the late 19th century, and have polished surfaces. In papers IV and V of this series we developed a method for cleaning noble metal mass standards in air to remove carbonaceous contamination. At the core of this ‘UVOPS’ protocol is the application of UV light and ozone gas generated in situ in air. The precise nature of the carbonaceous contamination that builds up on such surfaces is difficult to mimic demonstrably or quickly on new test surfaces, yet data from such tests are needed to provide the final confidence to allow UVOPS to be applied to a real 19th century kilogram prototype. Therefore, in the present work we have applied the UVOPS method to clean a platinum avoirdupois pound mass standard, ‘RS2’, manufactured in the mid-19th century. This is thought to have been polished in a similar manner to the kilogram prototypes. To our knowledge this platinum surface has not previously been cleaned by any method. We used x-ray photoelectron spectroscopy to identify organic contamination, and weighing to quantify the mass lost at each application of the UVOPS procedure. The UVOPS procedure is shown to be very effective. It is likely that the redefinition of the kilogram will require mass comparisons in vacuum in the years to come. Therefore, in addition to UVOPS a cleaning method for use in vacuum will also be needed. We introduce and evaluate gas cluster ion-beam (GCIB) treatment as a potential method for cleaning reference masses in vacuum. Again, application of this GCIB cleaning to a real artefact, RS2, allows us to make a realistic evaluation of its performance. While it has some attractive features, we cannot recommend it for cleaning mass standards in its present form.

10 CFR 32.101 - Schedule B-prototype tests for luminous safety devices for use in aircraft.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Schedule B-prototype tests for luminous safety devices for... thermometer. (d) Shock test. The device shall be dropped upon a concrete or iron surface in a 3-foot free gravitational fall, or shall be subjected to equivalent treatment in a test device simulating such a free fall...

Micro-Columnated Loop Heat Pipe: The Future of Electronic Substrates

NASA Astrophysics Data System (ADS)

Dhillon, Navdeep Singh

The modern world is run by semiconductor-based electronic systems. Due to continuous improvements in semiconductor device fabrication, there is a clear trend in the market towards the development of electronic devices and components that not only deliver enhanced computing power, but are also more compact. Thermal management has emerged as the primary challenge in this scenario where heat flux dissipation of electronic chips is increasing exponentially, but conventional cooling solutions such as conduction and convection are no longer feasible. To keep device junction temperatures within the safe operating limit, there is an urgent requirement for ultra-high-conductivity thermal substrates that not only absorb and transport large heat fluxes, but can also provide localized cooling to thermal hotspots. This dissertation describes the design, modeling, and fabrication of a phase change-based, planar, ultra-thin, passive thermal transport system that is inspired by the concept of loop heat pipes and capillary pumped loops. Fabricated on silicon and Pyrex wafers using microfabrication techniques, the micro-columnated loop heat pipe (muCLHP) can be integrated directly with densely packed or multiply-stacked electronic substrates, to provide localized high-heat-flux thermal management. The muCLHP employs a dual-scale coherent porous silicon(CPS)-based micro-columnated wicking structure, where the primary CPS wick provides large capillary forces for fluid transport, while a secondary surface-wick maximizes the rate of thin-film evaporation. To overcome the wick thickness limitation encountered in conventional loop heat pipes, strategies based on MEMS surface micromachining techniques were developed to reduce parasitic heat flow from the evaporator to the compensation chamber of the device. Finite element analysis was used to confirm this reduction in a planar evaporator design, thus enabling the generation of a large motive temperature head for continuous device operation. To predict the overall heat carrying capacity of the muCLHP in the capillary pumping limit, an analytical model was developed to account for a steady state pressure balance in the device flow loop. Based on this model, a design optimization study, employing monotonicity analysis and numerical optimization techniques, was undertaken. It was found that an optimized muCLHP device can absorb heat fluxes as large as 1293 W/cm2 when water is used as a working fluid. A finite volume method-based numerical model was also developed to compute the rates of thin-film evaporation from the patterned surface of the secondary wick. The numerical results indicated that, by properly optimizing the dual-scale wick topology, allowable evaporative heat fluxes can be made commensurate with the heat flux performance predicted by the capillary pumping limit. The latter part of the dissertation deals with the fabrication, packaging, and experimental testing of several in-plane-wicking micro loop heat pipe (muLHP) prototypes. These devices were fabricated on silicon and Pyrex substrates and closely resemble the muCLHP design philosophy, with the exception that the CPS wick is substituted with an easier to fabricate in-plane wick. A novel thermal-flux method was developed for the degassing and fluid charging of the muLHP prototypes. Experiments were conducted to study the process of evaporation and dynamics of the liquid and vapor phases in the device flow loop. Using these results, the overall device and individual component topologies critical to the operation of the two-phase flow loop were identified. A continuous two-phase device flow loop was demonstrated for applied evaporator heat fluxes as high as 41 W/cm2. The performance of these devices, currently found to be limited by the motive temperature head requirement, can be significantly improved by implementing the parasitic heat flow-reduction strategies developed in this work. The 3-D thin-film evaporation model, when integrated into the overall device modeling framework, will enable a design optimization of the micro-columnated wick for further device performance enhancements.

Patient specific ankle-foot orthoses using rapid prototyping

PubMed Central

2011-01-01

Background Prefabricated orthotic devices are currently designed to fit a range of patients and therefore they do not provide individualized comfort and function. Custom-fit orthoses are superior to prefabricated orthotic devices from both of the above-mentioned standpoints. However, creating a custom-fit orthosis is a laborious and time-intensive manual process performed by skilled orthotists. Besides, adjustments made to both prefabricated and custom-fit orthoses are carried out in a qualitative manner. So both comfort and function can potentially suffer considerably. A computerized technique for fabricating patient-specific orthotic devices has the potential to provide excellent comfort and allow for changes in the standard design to meet the specific needs of each patient. Methods In this paper, 3D laser scanning is combined with rapid prototyping to create patient-specific orthoses. A novel process was engineered to utilize patient-specific surface data of the patient anatomy as a digital input, manipulate the surface data to an optimal form using Computer Aided Design (CAD) software, and then download the digital output from the CAD software to a rapid prototyping machine for fabrication. Results Two AFOs were rapidly prototyped to demonstrate the proposed process. Gait analysis data of a subject wearing the AFOs indicated that the rapid prototyped AFOs performed comparably to the prefabricated polypropylene design. Conclusions The rapidly prototyped orthoses fabricated in this study provided good fit of the subject's anatomy compared to a prefabricated AFO while delivering comparable function (i.e. mechanical effect on the biomechanics of gait). The rapid fabrication capability is of interest because it has potential for decreasing fabrication time and cost especially when a replacement of the orthosis is required. PMID:21226898

Performance of the first prototype of the CALICE scintillator strip electromagnetic calorimeter

DOE PAGES

Francis, K.; Repond, J.; Schlereth, J.; ...

2014-11-01

A first prototype of a scintillator strip-based electromagnetic calorimeter was built, consisting of 26 layers of tungsten absorber plates interleaved with planes of 45 × 10 × 3 mm³ plastic scintillator strips. Data were collected using a positron test beam at DESY with momenta between 1 and 6 GeV/c. The prototype's performance is presented in terms of the linearity and resolution of the energy measurement. These results represent an important milestone in the development of highly granular calorimeters using scintillator strip technology. A number of possible design improvements were identified, which should be implemented in a future detector of thismore » type. This technology is being developed for a future linear collider experiment, aiming at the precise measurement of jet energies using particle flow techniques.« less

The LUX prototype detector: Heat exchanger development

DOE PAGES

Akerib, D. S.; Bai, X.; Bedikian, S.; ...

2013-01-24

The LUX (large underground xenon) detector is a two-phase xenon time projection chamber (TPC) designed to search for WIMP–nucleon dark matter interactions. As with all noble element detectors, continuous purification of the detector medium is essential to produce a large (> 1 ms) electron lifetime; this is necessary for efficient measurement of the electron signal which in turn is essential for achieving robust discrimination of signal from background events. Here, we describe the development of a novel purification system deployed in a prototype detector. The results from the operation of this prototype indicated heat exchange with an efficiency above 94%more » up to a flow rate of 42 slpm, allowing for an electron drift length greater than 1 m to be achieved in approximately 2 days and sustained for the duration of the testing period.« less

Surface Magnetic Fields on Giants and Supergiants

NASA Astrophysics Data System (ADS)

Lebre, Agnès

2018-04-01

After a short introduction to spectropolarimetry and the tecnics allowing for the detection of surface fields, I will review the numerous and various detections of magnetic fields at the surface of giant and supergiant stars. On Betelgeuse, the prototype of Red Supergiants, I will present recent results collected after a 10 years long spectropolarimetric survey.

SOSS User Guide

NASA Technical Reports Server (NTRS)

Zhu, Zhifan; Gridnev, Sergei; Windhorst, Robert D.

2015-01-01

This User Guide describes SOSS (Surface Operations Simulator and Scheduler) software build and graphic user interface. SOSS is a desktop application that simulates airport surface operations in fast time using traffic management algorithms. It moves aircraft on the airport surface based on information provided by scheduling algorithm prototypes, monitors separation violation and scheduling conformance, and produces scheduling algorithm performance data.

ELECTROCHEMICAL ARSENIC REMEDIATION IN RURAL BANGLADESH

EPA Science Inventory

In Year 1, we built a bench-scale continuous flow prototype (dubbed “Sushi” for its sushi-like electrode roll) and completed preliminary field trials in Bangladesh. We were also able to leverage additional funding to complete preliminary field trials in arsenic-...

Aramid Nanofiber Composites for Energy Storage Applications

NASA Astrophysics Data System (ADS)

Tung, Siu on

Lithium ion batteries and non-aqueous redox flow batteries represent two of the most important energy storage technologies to efficient electric vehicles and power grid, which are essential to decreasing U.S. dependence on fossil fuels and sustainable economic growth. Many of the developmental roadblocks for these batteries are related to the separator, an electrically insulating layer between the cathode and anode. Lithium dendrite growth has limited the performance and threatened the safety of lithium ion batteries by piercing the separator and causing internal shorts. In non-aqueous redox flow batteries, active material crossover through microporous separators and the general lack of a suitable ion conducting membrane has led to low operating efficiencies and rapid capacity fade. Developing new separators for these batteries involve the combination of different and sometimes seemingly contradictory properties, such as high ionic conductivity, mechanical stability, thermal stability, chemical stability, and selective permeability. In this dissertation, I present work on composites made from Kevlar-drived aramid nanofibers (ANF) through rational design and fabrication techniques. For lithium ion batteries, a dendrite suppressing layer-by-layer composite of ANF and polyethylene oxide is present with goals of high ionic conductivity, improved safety and thermal stability. For non-aqueous redox flow batteries, a nanoporous ANF separator with surface polyelectrolyte modification is used to achieve high coulombic efficiencies and cycle life in practical flow cells. Finally, manufacturability of ANF based separators is addressed through a prototype machine for continuous ANF separator production and a novel separator coated on anode assembly. In combination, these studies serve as a foundation for addressing the challenges in separator engineering for lithium ion batteries and redox flow batteries.

A wireless wearable surface functional electrical stimulator

NASA Astrophysics Data System (ADS)

Wang, Hai-Peng; Guo, Ai-Wen; Zhou, Yu-Xuan; Xia, Yang; Huang, Jia; Xu, Chong-Yao; Huang, Zong-Hao; Lü, Xiao-Ying; Wang, Zhi-Gong

2017-09-01

In this paper, a wireless wearable functional electrical stimulator controlled by Android phone with real-time-varying stimulation parameters for multichannel surface functional electrical stimulation application has been developed. It can help post-stroke patients using more conveniently. This study focuses on the prototype design, including the specific wristband concept, circuits and stimulation pulse-generation algorithm. A novel stimulator circuit with a driving stage using a complementary current source technique is proposed to achieve a high-voltage compliance, a large output impedance and an accurate linear voltage-to-current conversion. The size of the prototype has been significantly decreased to 17 × 7.5 × 1 cm3. The performance of the prototype has been tested with a loaded resistor and wrist extension/flexion movement of three hemiplegic patients. According to the experiments, the stimulator can generate four-channel charge-balanced biphasic stimulation with a voltage amplitude up to 60 V, and the pulse frequency and width can be adjusted in real time with a range of 100-600 μs and 20-80 Hz, respectively.

Product Development and its Comparative Analysis by SLA, SLS and FDM Rapid Prototyping Processes

NASA Astrophysics Data System (ADS)

Choudhari, C. M.; Patil, V. D.

2016-09-01

To grab market and meeting deadlines has increased the scope of new methods in product design and development. Industries continuously strive to optimize the development cycles with high quality and cost efficient products to maintain market competitiveness. Thus the need of Rapid Prototyping Techniques (RPT) has started to play pivotal role in rapid product development cycle for complex product. Dimensional accuracy and surface finish are the corner stone of Rapid Prototyping (RP) especially if they are used for mould development. The paper deals with the development of part made with the help of Selective Laser Sintering (SLS), Stereo-lithography (SLA) and Fused Deposition Modelling (FDM) processes to benchmark and investigate on various parameters like material shrinkage rate, dimensional accuracy, time, cost and surface finish. This helps to conclude which processes can be proved to be effective and efficient in mould development. In this research work the emphasis was also given to the design stage of a product development to obtain an optimum design solution for an existing product.

Darrieus wind-turbine and pump performance for low-lift irrigation pumping

NASA Astrophysics Data System (ADS)

Hagen, L. J.; Sharif, M.

1981-10-01

In the Great Plains about 15 percent of the irrigation water pumped on farms comes from surface water sources; for the United States as a whole, the figure is about 22 percent. Because of forecast fuel shortages, there is a need to develop alternative energy sources such as wind power for surface water pumping. Specific objectives of this investigation were to: design and assemble a prototype wind powered pumping system for low lift irrigation pumping; determine performance of the prototype system; design and test an irrigation system using the wind powered prototype in a design and test an farm application; and determine the size combinations of wind turbines, tailwater pits, and temporary storage reservoirs needed for successful farm application of wind powered tailwater pumping systems in western Kansas. The power source selected was a two bladed, 6 m diameter, 9 m tall Darrieus vertical axis wind turbine with 0.10 solidity and 36.1 M(2) swept area.

Rapidly prototyped three-dimensional nanofluidic channel networks in glass substrates.

PubMed

Ke, Kevin; Hasselbrink, Ernest F; Hunt, Alan J

2005-08-15

Microfluidic and nanofluidic technologies have long sought a fast, reliable method to overcome the creative limitations of planar fabrication methods, the resolution limits of lithography, and the materials limitations for fast prototyping. In the present work, we demonstrate direct 3D machining of submicrometer diameter, subsurface fluidic channels in glass, via optical breakdown near critical intensity, using a femtosecond pulsed laser. No postexposure etching or bonding is required; the channel network (or almost any arbitrary-shaped cavity below the surface) is produced directly from "art-to-part". The key to this approach is to use very low energy, highly focused, pulses in the presence of liquid. Microbubbles that result from laser energy deposition gently expand and extrude machining debris from the channels. These bubbles are in a highly damped, low Reynolds number regime, implying that surface spalling due to bubble collapse is unimportant. We demonstrate rapid prototyping of three-dimensional "jumpers", mixers, and other key components of complex 3D microscale analysis systems in glass substrates.

Simulation of blood flow using extended Boltzmann kinetic approach

NASA Astrophysics Data System (ADS)

Chen, Caixia; Chen, Hudong; Freed, David; Shock, Richard; Staroselsky, Ilya; Zhang, Raoyang; Ümit Coşkun, A.; Stone, Peter H.; Feldman, Charles L.

2006-03-01

Lattice Boltzmann (LB) simulations are conducted to obtain the detailed hydrodynamics in a variety of blood vessel setups, including a prototype stented channel and four human coronary artery geometries based on the images obtained from real patients. For a model of stented flow involving an S-shape stent, a pulsatile flow rate is applied as the inlet boundary condition, and the time- and space-dependent flow field is computed. The LB simulation is found to reproduce the analytical solutions for the velocity profiles and wall shear stress distributions for the pulsatile channel flow. For the coronary arteries, the distributions of wall shear stress, which is important for clinical diagnostic purposes, are in good agreement with the conventional CFD predictions.

The Stability of Particulate Ladden Laminar Boundary-Layer Flows

NASA Technical Reports Server (NTRS)

Acrivos, Andreas

1996-01-01

During the course of this investigation, the following two topics were studied theoretically: (1) forced convection and sedimentation past a flat plate, and (2) the effect of rain on airfoil performance. The prototype of the first topic is that of air flowing past the wing section of an aircraft under heavy rain and high windshear. The long-range objective of this project was to identify the various factors determining the dynamics of the flow and then to develop a theoretical framework for modeling such systems. The second topic focused on the idea that the presence of the gas-liquid interface (being the air flow around the airfoil and the thin liquid film created by the rain) accelerates flow separation and thus induces performance losses.

Inexpensive, rapid fabrication of polymer-film microfluidic autoregulatory valve for disposable microfluidics.

PubMed

Zhang, Xinjie; Zhu, Zhixian; Ni, Zhonghua; Xiang, Nan; Yi, Hong

2017-06-01

This work presents the fabrication of a microfluidic autoregulatory valve which is composed of several layers of thin polymer films (i.e., polyvinyl chloride (PVC), polyethylene terephthalate (PET) double-sided tape, and polydimethylsiloxane (PDMS)). Briefly, pulsed UV laser is employed to cut the microstructures of through grooves or holes in the thermoplastic polymer films, and then the polymer-film valves are precisely assembled through laminating the PDMS membranes to the thermoplastic polymer films through the roll-lamination method. The effective bonding between the PVC film and the PDMS membrane is realized using the planar seal method, and the valve is sandwiched and compressed by a home-made housing to achieve the good seal effect. Then, the flow performances of the prototype valve are examined, and constant flow autoregulation is realized under the static or dynamic test pressures. The long-term response of the valve is also studied and minimum flow-rate decrements are found over a long actuation time. The fabrication method proposed in this work is successful for the low-cost and fast prototyping of the polymer-film valve. We believe our method will also be broadly applicable for fabrication of other low-cost and disposable polymer-film microfluidic devices.

Investigation of PVdF active diaphragms for synthetic jets

NASA Astrophysics Data System (ADS)

Bailo, Kelly C.; Brei, Diann E.; Calkins, Frederick T.

2000-06-01

Current research has shown that aircraft can gain significant aerodynamic performance benefits by employing active flow control (AFC). One of the enabling technologies of AFC is the synthetic jet. Synthetic jets, also known as zero-net-mass flux actuators, act as bi-directional pumps injecting high momentum air into the local aerodynamic flow. Previous work has concentrated on high frequency synthetic jets based on piezoelectric active diaphragms such as Thunder actuators. Low frequency synthetic jets present a unique challenge requiring large displacements, which current technology has difficulty meeting. Boeing is investigating novel shaped low frequency synthetic jets that can modify the flow over fixed aircraft wings. This paper present the initial study of two promising active diaphragm concepts: a crescent shape and an opposing bender shape. These active diaphragms were numerically modeled utilizing the general-purpose finite element code ABAQUS. Using the ABAQUS results, the dynamic volume change within each jet was calculated and incorporated into an analytical linear Bernoulli model to predict the velocities and pressures at the nozzle. Simulations were performed to determine trends to assist in selection of prototype configurations. Prototypes of both diaphragm concepts were constructed from polyvinylidene fluoride and experimentally tested at Boeing with promising results.

Acoustic Measurements of an Uninstalled Spacecraft Cabin Ventilation Fan Prototype

NASA Technical Reports Server (NTRS)

Koch, L. Danielle; Brown, Clifford A.; Shook, Tony D.; Winkel, James; Kolacz, John S.; Podboy, Devin M.; Loew, Raymond A.; Mirecki, Julius H.

2012-01-01

Sound pressure measurements were recorded for a prototype of a spacecraft cabin ventilation fan in a test in the NASA Glenn Acoustical Testing Laboratory. The axial fan is approximately 0.089 m (3.50 in.) in diameter and 0.223 m (9.00 in.) long and has nine rotor blades and eleven stator vanes. At design point of 12,000 rpm, the fan was predicted to produce a flow rate of 0.709 cu m/s (150 cfm) and a total pressure rise of 925 Pa (3.72 in. of water) at 12,000 rpm. While the fan was designed to be part of a ducted atmospheric revitalization system, no attempt was made to throttle the flow or simulate the installed configuration during this test. The fan was operated at six speeds from 6,000 to 13,500 rpm. A 13-microphone traversing array was used to collect sound pressure measurements along two horizontal planes parallel to the flow direction, two vertical planes upstream of the fan inlet and two vertical planes downstream of the fan exhaust. Measurements indicate that sound at blade passing frequency harmonics contribute significantly to the overall audible noise produced by the fan at free delivery conditions.

Optical flows method for lightweight agile remote sensor design and instrumentation

NASA Astrophysics Data System (ADS)

Wang, Chong; Xing, Fei; Wang, Hongjian; You, Zheng

2013-08-01

Lightweight agile remote sensors have become one type of the most important payloads and were widely utilized in space reconnaissance and resource survey. These imaging sensors are designed to obtain the high spatial, temporary and spectral resolution imageries. Key techniques in instrumentation include flexible maneuvering, advanced imaging control algorithms and integrative measuring techniques, which are closely correlative or even acting as the bottle-necks for each other. Therefore, mutual restrictive problems must be solved and optimized. Optical flow is the critical model which to be fully represented in the information transferring as well as radiation energy flowing in dynamic imaging. For agile sensors, especially with wide-field-of view, imaging optical flows may distort and deviate seriously when they perform large angle attitude maneuvering imaging. The phenomena are mainly attributed to the geometrical characteristics of the three-dimensional earth surface as well as the coupled effects due to the complicated relative motion between the sensor and scene. Under this circumstance, velocity fields distribute nonlinearly, the imageries may badly be smeared or probably the geometrical structures are changed since the image velocity matching errors are not having been eliminated perfectly. In this paper, precise imaging optical flow model is established for agile remote sensors, for which optical flows evolving is factorized by two forms, which respectively due to translational movement and image shape changing. Moreover, base on that, agile remote sensors instrumentation was investigated. The main techniques which concern optical flow modeling include integrative design with lightweight star sensors along with micro inertial measurement units and corresponding data fusion, the assemblies of focal plane layout and control, imageries post processing for agile remote sensors etc. Some experiments show that the optical analyzing method is effective to eliminate the limitations for the performance indexes, and succeeded to be applied for integrative system design. Finally, a principle prototype of agile remote sensor designed by the method is discussed.

Wastewater treatment in tsunami affected areas of Thailand by constructed wetlands.

PubMed

Brix, H; Koottatep, T; Laugesen, C H

2007-01-01

The tsunami of December 2004 destroyed infrastructure in many coastal areas in South-East Asia. In January 2005, the Danish Government gave a tsunami relief grant to Thailand to re-establish the wastewater management services in some of the areas affected by the tsunami. This paper describes the systems which have been built at three locations: (a) Baan Pru Teau: A newly-built township for tsunami victims which was constructed with the contribution of the Thai Red Cross. Conventional septic tanks were installed for the treatment of blackwater from each household and its effluent and grey water (40 m3/day) are collected and treated at a 220 m2 subsurface flow constructed wetland. (b) Koh Phi Phi Don island: A wastewater collection system for the main business and hotel area of the island, a pumping station and a pressure pipe to the treatment facility, a multi-stage constructed wetland system and a system for reuse of treated wastewater. The constructed wetland system (capacity 400 m3/day) consists of vertical flow, horizontal subsurface flow, free water surface flow and pond units. Because the treatment plant is surrounded by resorts, restaurants and shops, the constructed wetland systems are designed with terrains as scenic landscaping. (c) Patong: A 5,000 m2 constructed wetland system has been established to treat polluted water from drainage canals which collect overflow from septic tanks and grey water from residential areas. It is envisaged that these three systems will serve as prototype demonstration systems for appropriate wastewater management in Thailand and other tropical countries.

Simulation of an active cooling system for photovoltaic modules

NASA Astrophysics Data System (ADS)

Abdelhakim, Lotfi

2016-06-01

Photovoltaic cells are devices that convert solar radiation directly into electricity. However, solar radiation increases the photovoltaic cells temperature [1] [2]. The temperature has an influence on the degradation of the cell efficiency and the lifetime of a PV cell. This work reports on a water cooling technique for photovoltaic panel, whereby the cooling system was placed at the front surface of the cells to dissipate excess heat away and to block unwanted radiation. By using water as a cooling medium for the photovoltaic solar cells, the overheating of closed panel is greatly reduced without prejudicing luminosity. The water also acts as a filter to remove a portion of solar spectrum in the infrared band but allows transmission of the visible spectrum most useful for the PV operation. To improve the cooling system efficiency and electrical efficiency, uniform flow rate among the cooling system is required to ensure uniform distribution of the operating temperature of the PV cells. The aims of this study are to develop a 3D thermal model to simulate the cooling and heat transfer in Photovoltaic panel and to recommend a cooling technique for the PV panel. The velocity, pressure and temperature distribution of the three-dimensional flow across the cooling block were determined using the commercial package, Fluent. The second objective of this work is to study the influence of the geometrical dimensions of the panel, water mass flow rate and water inlet temperature on the flow distribution and the solar panel temperature. The results obtained by the model are compared with experimental results from testing the prototype of the cooling device.

Rapid prototyping of soil moisture estimates using the NASA Land Information System

NASA Astrophysics Data System (ADS)

Anantharaj, V.; Mostovoy, G.; Li, B.; Peters-Lidard, C.; Houser, P.; Moorhead, R.; Kumar, S.

2007-12-01

The Land Information System (LIS), developed at the NASA Goddard Space Flight Center, is a functional Land Data Assimilation System (LDAS) that incorporates a suite of land models in an interoperable computational framework. LIS has been integrated into a computational Rapid Prototyping Capabilities (RPC) infrastructure. LIS consists of a core, a number of community land models, data servers, and visualization systems - integrated in a high-performance computing environment. The land surface models (LSM) in LIS incorporate surface and atmospheric parameters of temperature, snow/water, vegetation, albedo, soil conditions, topography, and radiation. Many of these parameters are available from in-situ observations, numerical model analysis, and from NASA, NOAA, and other remote sensing satellite platforms at various spatial and temporal resolutions. The computational resources, available to LIS via the RPC infrastructure, support e- Science experiments involving the global modeling of land-atmosphere studies at 1km spatial resolutions as well as regional studies at finer resolutions. The Noah Land Surface Model, available with-in the LIS is being used to rapidly prototype soil moisture estimates in order to evaluate the viability of other science applications for decision making purposes. For example, LIS has been used to further extend the utility of the USDA Soil Climate Analysis Network of in-situ soil moisture observations. In addition, LIS also supports data assimilation capabilities that are used to assimilate remotely sensed soil moisture retrievals from the AMSR-E instrument onboard the Aqua satellite. The rapid prototyping of soil moisture estimates using LIS and their applications will be illustrated during the presentation.

Characteristics of products generated by selective sintering and stereolithography rapid prototyping processes

NASA Technical Reports Server (NTRS)

Cariapa, Vikram

1993-01-01

The trend in the modern global economy towards free market policies has motivated companies to use rapid prototyping technologies to not only reduce product development cycle time but also to maintain their competitive edge. A rapid prototyping technology is one which combines computer aided design with computer controlled tracking of focussed high energy source (eg. lasers, heat) on modern ceramic powders, metallic powders, plastics or photosensitive liquid resins in order to produce prototypes or models. At present, except for the process of shape melting, most rapid prototyping processes generate products that are only dimensionally similar to those of the desired end product. There is an urgent need, therefore, to enhance the understanding of the characteristics of these processes in order to realize their potential for production. Currently, the commercial market is dominated by four rapid prototyping processes, namely selective laser sintering, stereolithography, fused deposition modelling and laminated object manufacturing. This phase of the research has focussed on the selective laser sintering and stereolithography rapid prototyping processes. A theoretical model for these processes is under development. Different rapid prototyping sites supplied test specimens (based on ASTM 638-84, Type I) that have been measured and tested to provide a data base on surface finish, dimensional variation and ultimate tensile strength. Further plans call for developing and verifying the theoretical models by carefully designed experiments. This will be a joint effort between NASA and other prototyping centers to generate a larger database, thus encouraging more widespread usage by product designers.

Final Report for DUSEL R&D: BetaCage: A Screener of Ultra-Low-Level Radioactive Surface Contamination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golwala, Sunil R.

2013-12-20

The eventual full-size, radiopure BetaCage will be a low-background, atmospheric-pressure neon drift chamber with unprecedented sensitivity to emitters of low-energy electrons and alpha particles. We expect that the prototype BetaCage already developed will be an excellent screener of alpha particles. Both the prototype and final BetaCage will provide new infrastructure for rare-event science.

Heat transfer and pressure drop measurements in prototypic heat exchanges for the supercritical carbon dioxide Brayton power cycles

NASA Astrophysics Data System (ADS)

Kruizenga, Alan Michael

An experimental facility was built to perform heat transfer and pressure drop measurements in supercritical carbon dioxide. Inlet temperatures ranged from 30--125 °C with mass velocities ranging from 118--1050 kg/m2s and system pressures of 7.5--10.2 MPa. Tests were performed in horizontal, upward, and downward flow conditions to test the influence of buoyancy forces on the heat transfer. Horizontal tests showed that for system pressures of 8.1 MPa and up standard Nusselt correlations predicted the heat transfer behavior with good agreement. Tests performed at 7.5 MPa were not well predicted by existing correlations, due to large property variations. The data collected in this work can be used to better understand heat transfer near the critical point. The CFD package FLUENT was found to yield adequate prediction for the heat transfer behavior for low pressure cases, where standard correlations were inaccurate, however it was necessary to have fine mesh spacing (y+˜1) in order to capture the observed behavior. Vertical tests found, under the test conditions considered, that flow orientation had little or no effect on the heat transfer behavior, even in flow regions where buoyancy forces should result in a difference between up and down flow heat transfer. CFD results found that for a given set of boundary conditions a large increase in the gravitational acceleration could cause noticeable heat transfer deterioration. Studies performed with CFD further led to the hypothesis that typical buoyancy induced heat transfer deterioration exhibited in supercritical flows were mitigated through a complex interaction with the inertial force, which is caused by bulk cooling of the flow. This hypothesis to explain the observed data requires further investigation. Prototypic heat exchangers channels (i.e. zig-zag) proved that the heat transfer coefficient was consistently three to four times higher as compared to straight channel geometry. However, the form pressure loss due to the presence of the corners within the channels caused an increase in pressure drop by four to five times the pressure drop measured in the straight channel. Based on the results, more innovative geometries were recommended for future testing to reduce form losses found in the typical prototypic geometries.

Evaluation of the Sentinel-3 Hydrologic Altimetry Processor prototypE (SHAPE) methods.

NASA Astrophysics Data System (ADS)

Benveniste, J.; Garcia-Mondéjar, A.; Bercher, N.; Fabry, P. L.; Roca, M.; Varona, E.; Fernandes, J.; Lazaro, C.; Vieira, T.; David, G.; Restano, M.; Ambrózio, A.

2017-12-01

Inland water scenes are highly variable, both in space and time, which leads to a much broader range of radar signatures than ocean surfaces. This applies to both LRM and "SAR" mode (SARM) altimetry. Nevertheless the enhanced along-track resolution of SARM altimeters should help improve the accuracy and precision of inland water height measurements from satellite. The SHAPE project - Sentinel-3 Hydrologic Altimetry Processor prototypE - which is funded by ESA through the Scientific Exploitation of Operational Missions Programme Element (contract number 4000115205/15/I-BG) aims at preparing for the exploitation of Sentinel-3 data over the inland water domain. The SHAPE Processor implements all of the steps necessary to derive rivers and lakes water levels and discharge from Delay-Doppler Altimetry and perform their validation against in situ data. The processor uses FBR CryoSat-2 and L1A Sentinel-3A data as input and also various ancillary data (proc. param., water masks, L2 corrections, etc.), to produce surface water levels. At a later stage, water level data are assimilated into hydrological models to derive river discharge. This poster presents the improvements obtained with the new methods and algorithms over the regions of interest (Amazon and Danube rivers, Vanern and Titicaca lakes).

Testing of Liquid Metal Components for Nuclear Surface Power Systems

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Godfroy, Thomas J.; Pearson, J. Boise

2010-01-01

The Early Flight Fission Test Facility (EFF-TF) was established by the Marshall Space Flight Center (MSFC) to provide a capability for performing hardware-directed activities to support multiple in-space nuclear reactor concepts by using a non-nuclear test methodology. This includes fabrication and testing at both the module/component level and near prototypic reactor configurations. The EFF-TF is currently supporting an effort to develop an affordable fission surface power (AFSP) system that could be deployed on the Lunar surface. The AFSP system is presently based on a pumped liquid metal-cooled (Sodium-Potassium eutectic, NaK-78) reactor design. This design was derived from the only fission system that the United States has deployed for space operation, the Systems for Nuclear Auxiliary Power (SNAP) 10A reactor, which was launched in 1965. Two prototypical components recently tested at MSFC were a pair of Stirling power conversion units that would be used in a reactor system to convert heat to electricity, and an annular linear induction pump (ALIP) that uses travelling electromagnetic fields to pump the liquid metal coolant through the reactor loop. First ever tests were conducted at MSFC to determine baseline performance of a pair of 1 kW Stirling convertors using NaK as the hot side working fluid. A special test rig was designed and constructed and testing was conducted inside a vacuum chamber at MSFC. This test rig delivered pumped NaK for the hot end temperature to the Stirlings and water as the working fluid on the cold end temperature. These test were conducted through a hot end temperature range between 400 to 550C in increments of 50 C and a cold end temperature range from 30 to 70 C in 20 C increments. Piston amplitudes were varied from 6 to 1 1mm in .5 mm increments. A maximum of 2240 Watts electric was produced at the design point of 550 hot end, 40 C cold end with a piston amplitude of 10.5mm. This power level was reached at a gross thermal efficiency of 28%. A baseline performance map was established for the pair of 1kW Stirling convertors. The performance data will then be used for design modification to the Stirling convertors. The ALIP tested at MSFC has no moving parts and no direct electrical connections to the liquid metal containing components. Pressure is developed by the interaction of the magnetic field produced by the stator and the current which flows as a result of the voltage induced in the liquid metal contained in the pump duct. Flow is controlled by variation of the voltage supplied to the pump windings. Under steady-state conditions, pump performance is measured for flow rates from 0.5-4.3 kg/s. The pressure rise developed by the pump to support these flow rates is roughly 5-65 kPa. The RMS input voltage (phase-to-phase voltage) ranges from 5-120 V, while the frequency can be varied arbitrarily up to 60 Hz. Performance is quantified at different loop temperature levels from 50 C up to 650 C, which is the peak operating temperature of the proposed AFSP reactor. The transient response of the pump is also evaluated to determine its behavior during startup and shut-down procedures.

Computer Animation of a Chemical Reaction.

ERIC Educational Resources Information Center

Eaker, Charles W.; Jacobs, Edwin L.

1982-01-01

Taking a prototype chemical reaction (molecular hydrogen plus hydrogen atom), constructs an accurate semiempirical, generalized diatomics-in-molecules potential energy surface, calculates motions of these atoms on this surface using REACTS trajectory program, and presents results as moving picture on a microcomputer graphics system. Provides…

The characterization of the antibacterial efficacy of an electrically activated silver ion-based surface system

NASA Astrophysics Data System (ADS)

Shirwaiker, Rohan A.

There have been growing concerns in the global healthcare system about the eradication of pathogens in hospitals and other health-critical environments. The problem has been aggravated by the overuse of antibiotics and antimicrobial agents leading to the emergence of antibiotic-resistant superbugs such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) which are difficult to kill. Lower immunity of sick patients coupled with the escalating concurrent problem of antibiotic-resistant pathogens has resulted in increasing incidences of hospital acquired (nosocomial) infections. There is an immediate need to control the transmission of such infections, primarily in healthcare environments, by creating touch-contact and work surfaces (e.g., door knobs, push plates, countertops) that utilize alternative antibacterial materials like the heavy metal, silver. Recent research has shown that it is silver in its ionic (Ag+ ) and not elemental form that is antibacterial. Thus, silver-based antibacterial surfaces have to release silver ions directly into the pathogenic environment (generally, an aqueous media) in order to be effective. This dissertation presents the study and analysis of a new silver-based surface system that utilizes low intensity direct electric current (LIDC) for generation of silver ions to primarily inhibit indirect contact transmission of infections. The broader objective of this research is to understand the design, and characterization of the electrically activated silver ion-based antibacterial surface system. The specific objectives of this dissertation include: (1) Developing a comprehensive system design, and identifying and studying its critical design parameters and functional mechanisms. (2) Evaluating effects of the critical design parameters on the antibacterial efficacy of the proposed surface system. (3) Developing a response surface model for the surface system performance. These objectives are achieved by formulating the system design, fabricating prototypes with appropriate design parameters, evaluating the prototypes using various physical and electrical characterization techniques, and characterizing the antibacterial efficacy of the prototypes using statistical experiments. The major contributions of this dissertation include: (1) Design of a systems focused approach that quantifies the potential effectiveness of silver ions under various configurations of the surface system design. (2) Development of meso and micro-scale fabrication methodologies for prototype fabrication. (3) Development of microbiological testing protocols utilizing variance reduction techniques to test the antibacterial efficacy of system prototypes. (4) Development of empirical models for the surface system using factorial design of experiments (DOE). Basic results from the research demonstrate significant antibacterial efficacy of the surface system against four dangerous bacteria including Staph aureus, Escherichia coli, Pseudomonas aeruginosa, and Enterococcus faecalis which are together responsible for more than 80% of nosocomial infections. Results of the DOE characterization study indicate the statistically significant contributions of three system parameters -- size of features, electric current, and type of bacteria -- to the antibacterial performance of the system. This dissertation synergistically utilizes knowledge and principles from three broader areas of research -- industrial engineering, materials science and microbiology -- to model, design, fabricate and characterize an electrically activated silver-ion based antibacterial surface system with practical applications in improving human health and healthcare systems. The research is aimed at promoting novel integrative research and development of technologies utilizing antibacterial properties of silver and other heavy metals.

Report on the Program "Fluid-mediated particle transport in geophysical flows" at the Kavli Institute for Theoretical Physics, UC Santa Barbara, September 23 to December 12, 2013

NASA Astrophysics Data System (ADS)

Jenkins, James T.; Meiburg, Eckart; Valance, Alexandre

2015-09-01

The Kavli Institute of Theoretical Physics (KITP) program held at UC Santa Barbara in the fall of 2013 addressed the dynamics of dispersed particulate flows in the environment. By focusing on the prototypes of aeolian transport and turbidity currents, it aimed to establish the current state of our understanding of such two-phase flows, to identify key open questions, and to develop collaborative research strategies for addressing these questions. Here, we provide a brief summary of the program outcome.

Direct Prototyping of Patterned Nanoporous Carbon: A Route from Materials to On-chip Devices

PubMed Central

Shen, Caiwei; Wang, Xiaohong; Zhang, Wenfeng; Kang, Feiyu

2013-01-01

Prototyping of nanoporous carbon membranes with three-dimensional microscale patterns is significant for integration of such multifunctional materials into various miniaturized systems. Incorporating nano material synthesis into microelectronics technology, we present a novel approach to direct prototyping of carbon membranes with highly nanoporous structures inside. Membranes with significant thicknesses (1 ~ 40 μm) are rapidly prototyped at wafer level by combining nano templating method with readily available microfabrication techniques, which include photolithography, high-temperature annealing and etching. In particular, the high-surface-area membranes are specified as three-dimensional electrodes for micro supercapacitors and show high performance compared to reported ones. Improvements in scalability, compatibility and cost make the general strategy promising for batch fabrication of operational on-chip devices or full integration of three-dimensional nanoporous membranes with existing micro systems. PMID:23887486

Fluid Dynamic Characterization of a Polymeric Heart Valve Prototype (Poli-Valve) tested under Continuous and Pulsatile Flow Conditions

PubMed Central

De Gaetano, Francesco; Serrani, Marta; Bagnoli, Paola; Brubert, Jacob; Stasiak, Joanna; Moggridge, Geoff D.; Costantino, Maria Laura

2016-01-01

Introduction Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy, the latter display better fluid dynamic behaviour but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the haemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of two groups of newly developed supra-annular tri-leaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves. Methods Two types of Poli-Valves made of SBC differing in polystyrene fraction content were tested under continuous and pulsatile flow conditions as prescribed by ISO 5840 Standard. An ad - hoc designed pulse duplicator allowed the valve prototypes to be tested at different flow rates and frequencies. Pressure and flow were recorded; pressure drops, effective orifice area (EOA), and regurgitant volume were computed to assess the valve’s behaviour. Results Both types Poli-Valves met the minimum requirements in terms of regurgitation and EOA as specified by ISO 5840 Standard. Results were compared with five mechanical heart valves (MHVs) and five tissue heart valves (THVs), currently available on the market. Conclusion Based on these results, polymeric heart valves based on styrenic block copolymers, as Poli-Valves are, can be considered as promising alternative for heart valve replacement in near future. PMID:26689146

Fluid dynamic characterization of a polymeric heart valve prototype (Poli-Valve) tested under continuous and pulsatile flow conditions.

PubMed

De Gaetano, Francesco; Serrani, Marta; Bagnoli, Paola; Brubert, Jacob; Stasiak, Joanna; Moggridge, Geoff D; Costantino, Maria Laura

2015-11-01

Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy; the latter display better fluid dynamic behavior but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the hemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of 2 groups of newly developed supra-annular, trileaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves. 2 types of Poli-Valves made of SBC and differing in polystyrene fraction content were tested under continuous and pulsatile flow conditions as prescribed by ISO 5840 Standard. A pulse duplicator designed ad hoc allowed the valve prototypes to be tested at different flow rates and frequencies. Pressure and flow were recorded; pressure drops, effective orifice area (EOA), and regurgitant volume were computed to assess the behavior of the valve. Both types of Poli-Valves met the minimum requirements in terms of regurgitation and EOA as specified by the ISO 5840 Standard. Results were compared with 5 mechanical heart valves (MHVs) and 5 tissue heart valves (THVs), currently available on the market. Based on these results, PHVs based on styrenic block copolymers, as are Poli-Valves, can be considered a promising alternative for heart valve replacement in the near future.

Inactivation of natural microflora and Escherichia coli K-12 on cantaloupe rind surfaces using wet steam treatments

USDA-ARS?s Scientific Manuscript database

The presence of human bacterial pathogens on cantaloupe rind surfaces and transfer to fresh-cut pieces during preparation continue to be a microbial safety hazard for the produce industry and consumers alike. A prototype flash steam lab unit was used to treat cantaloupe rind surfaces inoculated with...

Disposable MagLev centrifugal blood pump utilizing a cone-shaped impeller.

PubMed

Hijikata, Wataru; Sobajima, Hideo; Shinshi, Tadahiko; Nagamine, Yasuyuki; Wada, Suguru; Takatani, Setsuo; Shimokohbe, Akira

2010-08-01

To enhance the durability and reduce the blood trauma of a conventional blood pump with a cone-shaped impeller, a magnetically levitated (MagLev) technology has been applied to the BioPump BPX-80 (Medtronic Biomedicus, Inc., Minneapolis, MN, USA), whose impeller is supported by a mechanical bearing. The MagLev BioPump (MagLev BP), which we have developed, has a cone-shaped impeller, the same as that used in the BPX-80. The suspension and driving system, which is comprised of two degrees of freedom, radial-controlled magnetic bearing, and a simply structured magnetic coupling, eliminates any physical contact between the impeller and the housing. To reduce both oscillation of the impeller and current in the coils, the magnetic bearing system utilizes repetitive and zero-power compensators. In this article, we present the design of the MagLev mechanism, measure the levitational accuracy of the impeller and pressure-flow curves (head-quantity [HQ] characteristics), and describe in vitro experiments designed to measure hemolysis. For the flow-induced hemolysis of the initial design to be reduced, the blood damage index was estimated by using computational fluid dynamics (CFD) analysis. Stable rotation of the impeller in a prototype MagLev BP from 0 to 2750 rpm was obtained, yielding a flow rate of 5 L/min against a head pressure in excess of 250 mm Hg. Because the impeller of the prototype MagLev BP is levitated without contact, the normalized index of hemolysis was 10% less than the equivalent value with the BPX-80. The results of the CFD analysis showed that the shape of the outlet and the width of the fluid clearances have a large effect on blood damage. The prototype MagLev BP satisfied the required HQ characteristics (5 L/min, 250 mm Hg) for extracorporeal circulation support with stable levitation of the impeller and showed an acceptable level of hemolysis. The simulation results of the CFD analysis indicated the possibility of further reducing the blood damage of the prototype MagLev BP.

Lagrangian turbulence: Structures and mixing in admissible model flows

NASA Astrophysics Data System (ADS)

Ottino, Julio M.

1991-12-01

The goal of our research was to bridge the gap between modern ideas from dynamical systems and chaos and more traditional approaches to turbulence. In order to reach this objective we conducted theoretical and computational work on two systems: (1) a perturbed-Kelvin cat eyes flow, and (2) prototype solutions of the Navier-Stokes equations near solid walls. The main results obtained are two-fold: we have been able to produce flows capable of producing complex distributions of vorticity, and we have been able to construct flowfields, based on solutions of the Navier-Stokes equations, which are capable of displaying both Eulerian and Lagrangian turbulence. These results exemplify typical mechanisms of mixing enhancement in transitional flows.

An implantable centrifugal blood pump with a recirculating purge system (Cool-Seal system).

PubMed

Yamazaki, K; Litwak, P; Tagusari, O; Mori, T; Kono, K; Kameneva, M; Watach, M; Gordon, L; Miyagishima, M; Tomioka, J; Umezu, M; Outa, E; Antaki, J F; Kormos, R L; Koyanagi, H; Griffith, B P

1998-06-01

A compact centrifugal blood pump has been developed as an implantable left ventricular assist system. The impeller diameter is 40 mm, and pump dimensions are 55 x 64 mm. This first prototype, fabricated from titanium alloy, resulted in a pump weight of 400 g including a brushless DC motor. The weight of a second prototype pump was reduced to 280 g. The entire blood contacting surface is coated with diamond like carbon (DLC) to improve blood compatibility. Flow rates of over 7 L/min against 100 mm Hg pressure at 2,500 rpm with 9 W total power consumption have been measured. A newly designed mechanical seal with a recirculating purge system (Cool-Seal) is used for the shaft seal. In this seal system, the seal temperature is kept under 40 degrees C to prevent heat denaturation of blood proteins. Purge fluid also cools the pump motor coil and journal bearing. Purge fluid is continuously purified and sterilized by an ultrafiltration unit which is incorporated in the paracorporeal drive console. In vitro experiments with bovine blood demonstrated an acceptably low hemolysis rate (normalized index of hemolysis = 0.005 +/- 0.002 g/100 L). In vivo experiments are currently ongoing using calves. Via left thoracotomy, left ventricular (LV) apex descending aorta bypass was performed utilizing an expanded polytetrafluoroethylene (ePTFE) vascular graft with the pump placed in the left thoracic cavity. In 2 in vivo experiments, the pump flow rate was maintained at 5-9 L/min, and pump power consumption remained stable at 9-10 W. All plasma free Hb levels were measured at less than 15 mg/dl. The seal system has demonstrated good seal capability with negligible purge fluid consumption (<0.5 ml/day). In both calves, the pumps demonstrated trouble free continuous function over 6 month (200 days and 222 days).

Regenerable biocide delivery unit, volume 1

NASA Technical Reports Server (NTRS)

Atwater, James E.; Wheeler, Richard R., Jr.

1992-01-01

The Microbial Check Valve (MCV), which is currently used aboard the Shuttle Orbiter for disinfection of the potable water supply, is an expendable flow-through canister containing iodinated ion exchange resin. Means for extension of MCV life are desirable to avoid resupply penalties. The Phase 1 Regenerable Biocide Delivery Unit program demonstrated the feasibility of regenerating an MCV in situ, using a strong aqueous elemental iodine solution resulting from diversion of the MCV influent to a packed bed containing iodine crystals. In small column tests, eight manual regenerations of an MCV resin were accomplished. The term Regenerative Microbial Check Valve (RMCV) was adopted describing this new technology. The Phase 2 program resulted in the development of a full scale and fully autonomous prototype RMCV, capable of maintaining residual I(sub 2) levels between 2.0 - 4.0 mg/L for prolonged periods. During six months of testing at the Space Station baseline flow rate of 120 cm(sup 3)/min, the prototype RMCV underwent nine regenerations. RMCV life cycle tests, using a variety of influent streams, were conducted over an eighteen month period to determine the useful lives of MCV's incorporating this new technology and to determine ultimate failure mechanisms. MCV life extensions of 130 fold were demonstrated, limited only by the Phase 2 performance period. Based upon this work, it is certain that RMCV units can be developed to provide unattended biocide addition for the thirty year life of Space Station Freedom, or for other longer duration applications such as a Lunar Base or Mars mission. RMCV technology was also demonstrated capable of delivering, on demand, a concentrated aqueous I(sub 2) solution for potential use as a disinfectant during transient episodes of microbial surface contamination, for the control of biofilm formation, or as a preventative measure in systems which are particularly susceptible to the growth of microorganisms.

Experimental study of the free surface velocity field in an asymmetrical confluence

NASA Astrophysics Data System (ADS)

Creelle, Stephan; Mignot, Emmanuel; Schindfessel, Laurent; De Mulder, Tom

2017-04-01

The hydrodynamic behavior of open channel confluences is highly complex because of the combination of different processes that interact with each other. To gain further insights in how the velocity uniformization between the upstream channels and the downstream channel is proceeding, experiments are performed in a large scale 90 degree angled concrete confluence flume with a chamfered rectangular cross-section and a width of 0.98m. The dimensions and lay-out of the flume are representative for a prototype scale confluence in e.g. drainage and irrigation systems. In this type of engineered channels with sharp corners the separation zone is very large and thus the velocity difference between the most contracted section and the separation zone is pronounced. With the help of surface particle tracking velocimetry the velocity field is recorded from upstream of the confluence to a significant distance downstream of the confluence. The resulting data allow to analyze the evolution of the incoming flows (with a developed velocity profile) that interact with the stagnation zone and each other, causing a shear layer between the two bulk flows. Close observation of the velocity field near the stagnation zone shows that there are actually two shear layers in the vicinity of the upstream corner. Furthermore, the data reveals that the shear layer observed more downstream between the two incoming flows is actually one of the two shear layers next to the stagnation zone that continues, while the other shear layer ceases to exist. The extensive measurement domain also allows to study the shear layer between the contracted section and the separation zone. The shear layers of the stagnation zone between the incoming flows and the one between the contracted flow and separation zone are localized and parameters such as the maximum gradient, velocity difference and width of the shear layer are calculated. Analysis of these data shows that the shear layer between the incoming flows disappears quite quickly, because of the severe flow contraction that aids the flow uniformization. This is also accelerated because of a flow redistribution process that starts already upstream of the confluence, resulting in a lower than expected velocity difference over the shear layer between the bulk of the incoming flows. In contrast, the shear layer between the contracted section and the separation zone proves to be of a significantly higher order of magnitude, with large turbulent structures appearing that get transported far downstream. In conclusion, the resulting understanding of this analysis of velocity fields with a larger field of view shows that when analyzing confluence hydrodynamics, one should pay ample attention to analyze data far enough up and downstream to assess all the relevant processes.

A process for prototyping onboard payload displays for Space Station Freedom

NASA Technical Reports Server (NTRS)

Moore, Loretta A.

1992-01-01

Significant advances have been made in the area of Human-Computer Interface design. However, there is no well-defined process for going from user interface requirements to user interface design. Developing and designing a clear and consistent user interface for medium to large scale systems is a very challenging and complex task. The task becomes increasingly difficult when there is very little guidance and procedures on how the development process should flow from one stage to the next. Without a specific sequence of development steps each design becomes difficult to repeat, to evaluate, to improve, and to articulate to others. This research contributes a process which identifies the phases of development and products produced as a result of each phase for a rapid prototyping process to be used to develop requirements for the onboard payload displays for Space Station Freedom. The functional components of a dynamic prototyping environment in which this process can be carried out is also discussed. Some of the central questions which are answered here include: How does one go from specifications to an actual prototype? How is a prototype evaluated? How is usability defined and thus measured? How do we use the information from evaluation in redesign of an interface? and Are there techniques which allow for convergence on a design?

Utilizing of inner porous structure in injection moulds for application of special cooling method

NASA Astrophysics Data System (ADS)

Seidl, M.; Bobek, J.; Šafka, J.; Habr, J.; Nováková, I.; Běhálek, L.

2016-04-01

The article is focused on impact evaluation of controlled inner structure of production tools and new cooling method on regulation of thermal processes for injection moulding technology. The mould inserts with porous structure were cooled by means of liquid CO2 which is very progressive cooling method and enables very fast and intensive heat transfer among the plastic product, the production tool and cooling medium. The inserts were created using rapid prototype technology (DLSM) and they had a bi-component structure consisting of thin compact surface layer and defined porous inner structure of open cell character where liquid CO2 was flowing through. This analyse includes the evaluation of cooling efficiency for different inner structures and different time profiles for dosing of liquid CO2 into the porous structure. The thermal processes were monitored using thermocouples and IR thermal analyse of product surface and experimental device. Intensive heat removal influenced also the final structure and the shape and dimensional accuracy of the moulded parts that were made of semi-crystalline polymer. The range of final impacts of using intensive cooling method on the plastic parts was defined by DSC and dimensional analyses.

Active Dust Mitigation Technology for Thermal Radiators for Lunar Exploration

NASA Technical Reports Server (NTRS)

Calle, C. I.; Buhler, C. R.; Hogue, M. D.; Johansen, M. R.; Hopkins, J. W.; Holloway, N. M. H.; Connell, J. W.; Chen, A.; Irwin, S. A.; Case, S. O.;

Construction of the DHCAL

NASA Astrophysics Data System (ADS)

Francis, Kurt; CALICE Collaboration

Particle Flow Algorithms (PFAs) have been proposed as a method of improving the jet energy resolution of future colliding beam detectors. PFAs require calorimeters with high granularity to enable three-dimensional imaging of events. The Calorimeter for the Linear Collider Collaboration (CALICE) is developing and testing prototypes of such highly segmented calorimeters. In this context, a large prototype of a Digital Hadron Calorimeter (DHCAL) was developed and constructed by a group led by Argonne National Laboratory. The DHCAL consists of 52 layers, instrumented with Resistive Plate Chambers (RPCs) and interleaved with steel absorber plates. The RPCs are read out by 1 x 1 cm2 pads with a 1-bit resolution (digital readout). The DHCAL prototype has approximately 480,000 readout channels. This talk reports on the design, construction and commissioning of the DHCAL. The DHCAL was installed at the Fermilab Test Beam Facility in fall 2010 and data was collected through the summer 2011.

Predicting the next storm surge flood

USGS Publications Warehouse

Stamey, B.; Wang, Hongfang; Koterba, M.

2007-01-01

The Virginia Institute of Marine Science (VIMS), National Weather Services (NWS) Sterling and Wakefield, Weather Forecast Offices (WFO), and the Chesapeake Bay Observing System (CBOS) jointly developed a prototype system of a regional capability to address national problem. The system was developed to integrate high-resolution atmospheric and hydrodynamic and storm surge models, evaluate the ability of the prototype to predict land inundation in the Washington, D.C., and provide flooding results to Emergency Managers (EM) using portive. The system is a potential tool for NWS WFOs to provide support to the EMs, first in the Chesapeake Bay region and then in other coastal regions by applying similar approaches in other coastal and Great Lakes regions. The Chesapeake Inundation Prediction System (CIPS) also is building on the initial prototype to predict the combined effects of storm surge and tidal and river flow inundation in the Chesapeake Bay and its tributaries.

Development of Trace Contaminant Control Prototypes for the Primary Life Support System (PLSS)

NASA Technical Reports Server (NTRS)

Wojtowicz, Marek; Cosgrove, Joseph E.; Serio, Michael E.; Nalette, Tim; Guerrero, Sandra V.; Papale, William; Wilburn, Monique S.

2017-01-01

Results are presented on the development of Trace Contaminant Control (TCC) Prototypes for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). The current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. Data on sorption and desorption of ammonia and formaldehyde, which are major TCs of concern, as well as pressure-drop calculations were used to design and test 1/6-scale and full-scale trace contaminant control system (TCCS) prototypes. Carbon sorbents were fabricated in both the granular and foam-supported forms. Sorbent performance was tested for ammonia sorption and vacuum regeneration in 1/6-scale, and pressure-drop characteristics were measured at flow rates relevant to the PLSS application.

Digital Distribution of Advertising for Publications (DDAP): a graphic arts prototype of electronic intermedia publishing (EIP)

NASA Astrophysics Data System (ADS)

Dunn, Patrice M.

1998-01-01

The Digital Distribution of Advertising for Publications (DDAP) is a graphic arts industry prototype of Electronic Intermedia Publishing (EIP). EIP is a strategic, multi- industrial concept that seeks to enable the capture and input of volumes of data (i.e., both raster and object oriented data -- as well as the latter's antecedent which is vector data -- color data and black-and-white data) from a multiplicity of devices; then flowing, controlling, manipulating, modifying, storing, retrieving, transmitting, and shipping, that data through an industrial process for output to a multiplicity of output devices (e.g., ink on paper, toner on paper, bits and bytes on CD ROM, Internet, Multimedia, HDTV, etc.). As the technical requirements of the print medium are among the most rigorous in the Intermedia milieu the DDAP prototype addresses some of the most challenging issues faced in Electronic Intermedia Publishing (EIP).

Design and prototype fabrication of a 30 tesla cryogenic magnet

NASA Technical Reports Server (NTRS)

Prok, G. M.; Swanson, M. C.; Brown, G. V.

1977-01-01

A liquid neon cooled magnet was designed to produce 30 teslas in steady operation. To ensure the correctness of the heat transfer relationships used, supercritical neon heat transfer tests were made. Other tests made before the final design included tests on the effect of the magnetic field on pump motors, tensile shear tests on the cryogenic adhesives, and simulated flow studies for the coolant. The magnet will consist of two pairs of coils, cooled by forced convection of supercritical neon. Heat from the supercritical neon will be rejected through heat exchangers which are made of roll bonded copper panels and are submerged in a pool of saturated liquid neon. A partial mock up coil was wound to identify the tooling required to wind the magnet. This was followed by winding a prototype pair of coils. The prototype winding established procedures for fabricating the final magnet and revealed slight changes needed in the final design.

Similarity Theory of Withdrawn Water Temperature Experiment

PubMed Central

2015-01-01

Selective withdrawal from a thermal stratified reservoir has been widely utilized in managing reservoir water withdrawal. Besides theoretical analysis and numerical simulation, model test was also necessary in studying the temperature of withdrawn water. However, information on the similarity theory of the withdrawn water temperature model remains lacking. Considering flow features of selective withdrawal, the similarity theory of the withdrawn water temperature model was analyzed theoretically based on the modification of governing equations, the Boussinesq approximation, and some simplifications. The similarity conditions between the model and the prototype were suggested. The conversion of withdrawn water temperature between the model and the prototype was proposed. Meanwhile, the fundamental theory of temperature distribution conversion was firstly proposed, which could significantly improve the experiment efficiency when the basic temperature of the model was different from the prototype. Based on the similarity theory, an experiment was performed on the withdrawn water temperature which was verified by numerical method. PMID:26065020

Prototyping the HPDP Chip on STM 65 NM Process

NASA Astrophysics Data System (ADS)

Papadas, C.; Dramitinos, G.; Syed, M.; Helfers, T.; Dedes, G.; Schoellkopf, J.-P.; Dugoujon, L.

2011-08-01

Currently Astrium GmbH is involved in the of the High Performance Data Processor (HPDP) development programme for telecommunication applications under a DLR contract. The HPDP project targets the implementation of the commercially available reconfigurable array processor IP (XPP from the company PACT XPP Technologies) in a radiation hardened technology.In the current complementary development phase funded under the Greek Industry Incentive scheme, it is planned to prototype the HPDP chip in commercial STM 65 nm technology. In addition it is also planned to utilise the preliminary radiation hardened components of this library wherever possible.This abstract gives an overview of the HPDP chip architecture, the basic details of the STM 65 nm process and the design flow foreseen for the prototyping. The paper will discuss the development and integration issues involved in using the STM 65 nm process (also including the available preliminary radiation hardened components) for designs targeted to be used in space applications.

STRUTEX: A prototype knowledge-based system for initially configuring a structure to support point loads in two dimensions

NASA Technical Reports Server (NTRS)

Robers, James L.; Sobieszczanski-Sobieski, Jaroslaw

1989-01-01

Only recently have engineers begun making use of Artificial Intelligence (AI) tools in the area of conceptual design. To continue filling this void in the design process, a prototype knowledge-based system, called STRUTEX has been developed to initially configure a structure to support point loads in two dimensions. This prototype was developed for testing the application of AI tools to conceptual design as opposed to being a testbed for new methods for improving structural analysis and optimization. This system combines numerical and symbolic processing by the computer with interactive problem solving aided by the vision of the user. How the system is constructed to interact with the user is described. Of special interest is the information flow between the knowledge base and the data base under control of the algorithmic main program. Examples of computed and refined structures are presented during the explanation of the system.

Impacts assessment of dynamic speed harmonization with queue warning : task 3, impacts assessment report.

DOT National Transportation Integrated Search

2015-06-01

This report assesses the impacts of a prototype of Dynamic Speed Harmonization (SPD-HARM) with Queue Warning (Q-WARN), which are two component applications of the Intelligent Network Flow Optimization (INFLO) bundle. The assessment is based on an ext...

Development of a prototype two-phase thermal bus system for Space Station

NASA Technical Reports Server (NTRS)

Myron, D. L.; Parish, R. C.

1987-01-01

This paper describes the basic elements of a pumped two-phase ammonia thermal control system designed for microgravity environments, the development of the concept into a Space Station flight design, and design details of the prototype to be ground-tested in the Johnson Space Center (JSC) Thermal Test Bed. The basic system concept is one of forced-flow heat transport through interface heat exchangers with anhydrous ammonia being pumped by a device expressly designed for two-phase fluid management in reduced gravity. Control of saturation conditions, and thus system interface temperatures, is accomplished with a single central pressure regulating valve. Flow control and liquid inventory are controlled by passive, nonelectromechanical devices. Use of these simple control elements results in minimal computer controls and high system reliability. Building on the basic system concept, a brief overview of a potential Space Station flight design is given. Primary verification of the system concept will involve testing at JSC of a 25-kW ground test article currently in fabrication.

DOE Office of Scientific and Technical Information (OSTI.GOV)

BRISC is a developmental prototype for a nextgeneration “systems-level” integrated performance and safety code (IPSC) for nuclear reactors. Its development served to demonstrate how a lightweight multi-physics coupling approach can be used to tightly couple the physics models in several different physics codes (written in a variety of languages) into one integrated package for simulating accident scenarios in a liquid sodium cooled “burner” nuclear reactor. For example, the RIO Fluid Flow and Heat transfer code developed at Sandia (SNL: Chris Moen, Dept. 08005) is used in BRISC to model fluid flow and heat transfer, as well as conduction heat transfermore » in solids. Because BRISC is a prototype, its most practical application is as a foundation or starting point for developing a true production code. The sub-codes and the associated models and correlations currently employed within BRISC were chosen to cover the required application space and demonstrate feasibility, but were not optimized or validated against experimental data within the context of their use in BRISC.« less

Confinement of nonneutral plasmas in the Prototype Ring Trap device

NASA Astrophysics Data System (ADS)

Himura, Haruhiko; Yoshida, Zensho; Nakashima, Chihiro; Morikawa, Junji; Kakuno, Hidekazu; Tahara, Shigeru; Shibayama, Norihisa

1999-12-01

Recently, an internal-ring device named Proto-RT (Prototype Ring Trap) was constructed at University of Tokyo, and experiments on the device have been intensively conducted. The main goal of Proto-RT is to explore an innovative method to attain a plasma equilibrium with extremely high-β (β>1) in a toroidal geometry using non-neutral condition. At the first series of the experiments, pure electron plasmas (ne˜1013m-3) have been successfully confined inside a separatrix. No disruption is so far observed. The confinement time of the electron plasmas is of order 0.1 ms for an X point configuration. The non-neutrality of Δne˜1013m-3 is already beyond the critical value which is required to produce an enough self-electric field E in non-neutral plasmas with n0˜1019m-3, causing a strong E×B flow thoroughly over the plasmas where the hydrodynamic pressure of the flow is predicted to balance with the thermal pressure of the plasmas.

Analysis of dynamics and fit of diving suits

NASA Astrophysics Data System (ADS)

Mahnic Naglic, M.; Petrak, S.; Gersak, J.; Rolich, T.

2017-10-01

Paper presents research on dynamical behaviour and fit analysis of customised diving suits. Diving suits models are developed using the 3D flattening method, which enables the construction of a garment model directly on the 3D computer body model and separation of discrete 3D surfaces as well as transformation into 2D cutting parts. 3D body scanning of male and female test subjects was performed with the purpose of body measurements analysis in static and dynamic postures and processed body models were used for construction and simulation of diving suits prototypes. All necessary parameters, for 3D simulation were applied on obtained cutting parts, as well as parameters values for mechanical properties of neoprene material. Developed computer diving suits prototypes were used for stretch analysis on areas relevant for body dimensional changes according to dynamic anthropometrics. Garment pressures against the body in static and dynamic conditions was also analysed. Garments patterns for which the computer prototype verification was conducted were used for real prototype production. Real prototypes were also used for stretch and pressure analysis in static and dynamic conditions. Based on the obtained results, correlation analysis between body changes in dynamic positions and dynamic stress, determined on computer and real prototypes, was performed.

Sustainable earth-based vs. conventional construction systems in the Mediterranean climate: Experimental analysis of thermal performance

NASA Astrophysics Data System (ADS)

Serrano, S.; de Gracia, A.; Pérez, G.; Cabeza, L. F.

2017-10-01

The building envelope has high potential to reduce the energy consumption of buildings according to the International Energy Agency (IEA) because it is involved along all the building process: design, construction, use, and end-of-life. The present study compares the thermal behavior of seven different building prototypes tested under Mediterranean climate: two of them were built with sustainable earth-based construction systems and the other five, with conventional brick construction systems. The tested earth-based construction systems consist of rammed earth walls and wooden green roofs, which have been adapted to contemporary requirements by reducing their thickness. In order to balance the thermal response, wooden insulation panels were placed in one of the earth prototypes. All building prototypes have the same inner dimensions and orientation, and they are fully monitored to register inner temperature and humidity, surface walls temperatures and temperatures inside walls. Furthermore, all building prototypes are equipped with a heat pump and an electricity meter to measure the electrical energy consumed to maintain a certain level of comfort. The experimentation was performed along a whole year by carrying out several experiments in free floating and controlled temperature conditions. This study aims at demonstrating that sustainable construction systems can behave similarly or even better than conventional ones under summer and winter conditions. Results show that thermal behavior is strongly penalized when rammed earth wall thickness is reduced. However, the addition of 6 cm of wooden insulation panels in the outer surface of the building prototype successfully improves the thermal response.

An improved Abbott ARCHITECT assay for the detection of hepatitis B virus surface antigen (HBsAg).

PubMed

Lou, Sheng C; Pearce, Sandra K; Lukaszewska, Teresa X; Taylor, Russell E; Williams, Gregg T; Leary, Thomas P

2011-05-01

The sensitive and accurate detection of hepatitis B virus surface antigen (HBsAg) is critical to the identification of infection and the prevention of transfusion transmitted disease. Improvement in HBsAg assay sensitivity is essential to reduce the window to detect an acute HBV infection. Additionally, the sensitive detection of HBsAg mutants that continue to evolve due to vaccine escape, immune selection and an error prone reverse transcriptase is a necessity. A fully automated HBsAg prototype assay on the Abbott ARCHITECT instrument was developed to improve sensitivity and mutant detection. This magnetic microparticle-based assay utilizes anti-HBsAg monoclonal antibodies to capture antigen present in serum or plasma. Captured antigen is then detected using anti-HBsAg antibody conjugated with the chemiluminescent compound, acridinium. The sensitivity of the ARCHITECT HBsAg prototype assay was improved as compared to the current ARCHITECT, PRISM, and competitor HBsAg assays. The enhancement in assay sensitivity was demonstrated by the use of commercially available HBV seroconversion panels. The prototype assay detected more panel members (185 of 383) vs. the current ARCHITECT (171), PRISM (181), or competitor HBsAg assays (73/140 vs. 62/140, respectively). The ARCHITECT prototype assay also efficiently detected all mutants evaluated. Finally, the sensitivity improvement did not compromise the specificity of the assay (99.94%). An improved Abbott ARCHITECT HBsAg prototype assay with enhanced detection of HBsAg and HBsAg mutants, as well as equivalent specificity was developed for the detection, diagnosis, and management of HBV infection. Copyright © 2011 Elsevier B.V. All rights reserved.

Persistence of F-Specific RNA Coliphages in Surface Waters from a Produce Production Region along the Central Coast of California.

PubMed

Ravva, Subbarao V; Sarreal, Chester Z

2016-01-01

F+ RNA coliphages (FRNA) are used to source-track fecal contamination and as surrogates for enteric pathogen persistence in the environment. However, the environmental persistence of FRNA is not clearly understood and necessitates the evaluation of the survival of prototype and environmental isolates of FRNA representing all four genogroups in surface waters from the central coast of California. Water temperature played a significant role in persistence-all prototype and environmental strains survived significantly longer at 10 °C compared to 25 °C. Similarly, the availability of host bacterium was found to be critical in FRNA survival. In the absence of E. coli F(amp), all prototypes of FRNA disappeared rapidly with a D-value (days for one log reduction) of <1.2 d from water samples incubated at 25 °C; the longest surviving prototype was SP. However, in the presence of the host, the order of persistence at 25 °C was QB>MS2>SP>GA and at 10 °C it was QB = MS2>GA>SP. Significant differences in survival were observed between prototypes and environmental isolates of FRNA. While most environmental isolates disappeared rapidly at 25 °C and in the absence of the host, members of genogroups GIII and GI persisted longer with the host compared to members of GII and GIV. Consequentially, FRNA based source tracking methods can be used to detect phages from recent fecal contamination along with those that persist longer in the environment as a result of cooler temperatures and increased host presence.

Persistence of F-Specific RNA Coliphages in Surface Waters from a Produce Production Region along the Central Coast of California

PubMed Central

Ravva, Subbarao V.; Sarreal, Chester Z.

2016-01-01

F+ RNA coliphages (FRNA) are used to source-track fecal contamination and as surrogates for enteric pathogen persistence in the environment. However, the environmental persistence of FRNA is not clearly understood and necessitates the evaluation of the survival of prototype and environmental isolates of FRNA representing all four genogroups in surface waters from the central coast of California. Water temperature played a significant role in persistence–all prototype and environmental strains survived significantly longer at 10°C compared to 25°C. Similarly, the availability of host bacterium was found to be critical in FRNA survival. In the absence of E. coli Famp, all prototypes of FRNA disappeared rapidly with a D-value (days for one log reduction) of <1.2 d from water samples incubated at 25°C; the longest surviving prototype was SP. However, in the presence of the host, the order of persistence at 25°C was QB>MS2>SP>GA and at 10°C it was QB = MS2>GA>SP. Significant differences in survival were observed between prototypes and environmental isolates of FRNA. While most environmental isolates disappeared rapidly at 25°C and in the absence of the host, members of genogroups GIII and GI persisted longer with the host compared to members of GII and GIV. Consequentially, FRNA based source tracking methods can be used to detect phages from recent fecal contamination along with those that persist longer in the environment as a result of cooler temperatures and increased host presence. PMID:26784030

Comparison of grey water treatment performance by a cascading sand filter and a constructed wetland.

PubMed

Kadewa, W W; Le Corre, K; Pidou, M; Jeffrey, P J; Jefferson, B

2010-01-01

A novel unplanted vertical flow subsurface constructed wetland technology comprising three shallow beds (0.6 m length, 0.45 m width and 0.2 m depth) arranged in a cascading series and a standard single-pass Vertical Flow Planted Constructed Wetland (VFPCW, 6 m² and 0.7 m depth) were tested for grey water treatment. Particular focus was on meeting consent for published wastewater reuse parameters and removal of anionic surfactants. Treatment performance at two hydraulic loading rates (HLR) of 0.08, and 0.17 m³ m⁻² d⁻¹ were compared. Both technologies effectively removed more than 90% turbidity and more than 96% for organics with the prototype meeting the most stringent reuse standard of < 2 NTU and <10 mg/L. However, surfactant removal in the VFPCW was higher (76-85%) than in the prototype which only achieved more than 50% removal at higher loading rate. Generally, the prototype performed consistently better than the VFPCW except for surfactant removal. However, at higher loading rates, both systems did not meet the reuse standard of <1 mg L⁻¹ for anionic surfactants. This observation confirms that shallow beds provide a more oxidised environment leading to higher BOD₅ and COD removals. Presence of plants in the VFPCW led to higher anionic surfactant removal, through increased microbial and sorption processes.

Process-Structure-Property Relationships for 316L Stainless Steel Fabricated by Additive Manufacturing and Its Implication for Component Engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Nancy; Yee, J.; Zheng, B.

We investigate the process-structure-property relationships for 316L stainless steel prototyping utilizing 3-D laser engineered net shaping (LENS), a commercial direct energy deposition additive manufacturing process. Our study concluded that the resultant physical metallurgy of 3-D LENS 316L prototypes is dictated by the interactive metallurgical reactions, during instantaneous powder feeding/melting, molten metal flow and liquid metal solidification. This study also showed 3-D LENS manufacturing is capable of building high strength and ductile 316L prototypes due to its fine cellular spacing from fast solidification cooling, and the well-fused epitaxial interfaces at metal flow trails and interpass boundaries. However, without further LENS processmore » control and optimization, the deposits are vulnerable to localized hardness variation attributed to heterogeneous microstructure, i.e., the interpass heat-affected zone (HAZ) from repetitive thermal heating during successive layer depositions. Most significantly, the current deposits exhibit anisotropic tensile behavior, i.e., lower strain and/or premature interpass delamination parallel to build direction (axial). This anisotropic behavior is attributed to the presence of interpass HAZ, which coexists with flying feedstock inclusions and porosity from incomplete molten metal fusion. Our current observations and findings contribute to the scientific basis for future process control and optimization necessary for material property control and defect mitigation.« less

Process-Structure-Property Relationships for 316L Stainless Steel Fabricated by Additive Manufacturing and Its Implication for Component Engineering

DOE PAGES

Yang, Nancy; Yee, J.; Zheng, B.; ...

2016-12-08

We investigate the process-structure-property relationships for 316L stainless steel prototyping utilizing 3-D laser engineered net shaping (LENS), a commercial direct energy deposition additive manufacturing process. Our study concluded that the resultant physical metallurgy of 3-D LENS 316L prototypes is dictated by the interactive metallurgical reactions, during instantaneous powder feeding/melting, molten metal flow and liquid metal solidification. This study also showed 3-D LENS manufacturing is capable of building high strength and ductile 316L prototypes due to its fine cellular spacing from fast solidification cooling, and the well-fused epitaxial interfaces at metal flow trails and interpass boundaries. However, without further LENS processmore » control and optimization, the deposits are vulnerable to localized hardness variation attributed to heterogeneous microstructure, i.e., the interpass heat-affected zone (HAZ) from repetitive thermal heating during successive layer depositions. Most significantly, the current deposits exhibit anisotropic tensile behavior, i.e., lower strain and/or premature interpass delamination parallel to build direction (axial). This anisotropic behavior is attributed to the presence of interpass HAZ, which coexists with flying feedstock inclusions and porosity from incomplete molten metal fusion. Our current observations and findings contribute to the scientific basis for future process control and optimization necessary for material property control and defect mitigation.« less

Natural convection in melt crystal growth - The influence of flow pattern on solute segregation

NASA Technical Reports Server (NTRS)

Brown, R. A.; Yamaguchi, Y.; Chang, C. J.

1982-01-01

The results of two lines of research aimed at calculating the structure of the flows driven by buoyancy in small-scale crystal growth systems and at understanding the coupling between these flows, the shape of the solidification interface, and dopant segregation in the crystal are reviewed. First, finite-element methods are combined with computer-aided methods for detecting multiple steady solutions to analyze the structure of the buoyancy-driven axisymmetric flows in a vertical cylinder heated from below. This system exhibits onset of convection, multiple steady flows, and loss of the primary stable flow beyond a critical value of the Rayleigh number. Second, results are presented for calculations of convection, melt/solid interface shape, and dopant segregation within a vertical ampoule with thermal boundary conditions that represent a prototype of the vertical Bridgman growth system.

Velocity Vector Field Visualization of Flow in Liquid Acquisition Device Channel

NASA Technical Reports Server (NTRS)

McQuillen, John B.; Chao, David F.; Hall, Nancy R.; Zhang, Nengli

2012-01-01

A capillary flow liquid acquisition device (LAD) for cryogenic propellants has been developed and tested in NASA Glenn Research Center to meet the requirements of transferring cryogenic liquid propellants from storage tanks to an engine in reduced gravity environments. The prototypical mesh screen channel LAD was fabricated with a mesh screen, covering a rectangular flow channel with a cylindrical outlet tube, and was tested with liquid oxygen (LOX). In order to better understand the performance in various gravity environments and orientations at different liquid submersion depths of the screen channel LAD, a series of computational fluid dynamics (CFD) simulations of LOX flow through the LAD screen channel was undertaken. The resulting velocity vector field visualization for the flow in the channel has been used to reveal the gravity effects on the flow in the screen channel.

Assimilation of Smos Observations to Generate a Prototype SMAP Level 4 Surface and Root-Zone Soil Moisture Product

NASA Technical Reports Server (NTRS)

Reichle, Rolf H.; De Lannoy, Gabrielle J. M.; Crow, Wade T.; Koster, Randal D.; Kimball, John

2012-01-01

The Soil Moisture Active and Passive (SMAP; [1]) mission is being implemented by NASA for launch in October 2014. The primary science objectives of SMAP are to enhance understanding of land surface controls on the water, energy and carbon cycles, and to determine their linkages. Moreover, the high-resolution soil moisture mapping provided by SMAP has practical applications in weather and seasonal climate prediction, agriculture, human health, drought and flood decision support. The Soil Moisture and Ocean Salinity (SMOS; [2]) mission was launched by ESA in November 2009 and has since been observing L-band (1.4 GHz) upwelling passive microwaves. In this paper we describe our use of SMOS brightness temperature observations to generate a prototype of the planned SMAP Level 4 Surface and Root-zone Soil Moisture (L4_SM) product [5].

Vibration-immune high-sensitivity profilometer built with the technique of composite interferometry.

PubMed

Lin, Yu-Kai; Chang, Chun-Wei; Hou, Max T; Hsu, I-Jen

2016-03-10

A prototype of a profilometer was built with the technique of composite interferometry for measurement of the distribution of both the amplitude and phase information of the surface of a material simultaneously. The composite interferometer was composed of a Michelson interferometer for measuring the surface profile of the sample and a Mach-Zehnder interferometer for measuring the phase deviation caused by the scanning component and environmental perturbations. A high-sensitivity surface profile can be obtained by use of the phase compensation mechanism through subtraction of the phases of the interferograms detected in the two interferometers. With the new design and improvement of robustness of the optical system, the measurement speed and accuracy were significantly improved. Furthermore, an additional optical delay component results in a higher sensitivity of the interference signal. This prototype of vibration-immune profilometer was examined to have a displacement sensitivity of 0.64 nm.

Quantitative evaluation of performance of three-dimensional printed lenses

NASA Astrophysics Data System (ADS)

Gawedzinski, John; Pawlowski, Michal E.; Tkaczyk, Tomasz S.

2017-08-01

We present an analysis of the shape, surface quality, and imaging capabilities of custom three-dimensional (3-D) printed lenses. 3-D printing technology enables lens prototypes to be fabricated without restrictions on surface geometry. Thus, spherical, aspherical, and rotationally nonsymmetric lenses can be manufactured in an integrated production process. This technique serves as a noteworthy alternative to multistage, labor-intensive, abrasive processes, such as grinding, polishing, and diamond turning. Here, we evaluate the quality of lenses fabricated by Luxexcel using patented Printoptical©; technology that is based on an inkjet printing technique by comparing them to lenses made with traditional glass processing technologies (grinding, polishing, etc.). The surface geometry and roughness of the lenses were evaluated using white-light and Fizeau interferometers. We have compared peak-to-valley wavefront deviation, root mean square (RMS) wavefront error, radii of curvature, and the arithmetic roughness average (Ra) profile of plastic and glass lenses. In addition, the imaging performance of selected pairs of lenses was tested using 1951 USAF resolution target. The results indicate performance of 3-D printed optics that could be manufactured with surface roughness comparable to that of injection molded lenses (Ra<20 nm). The RMS wavefront error of 3-D printed prototypes was at a minimum 18.8 times larger than equivalent glass prototypes for a lens with a 12.7 mm clear aperture, but, when measured within 63% of its clear aperture, the 3-D printed components' RMS wavefront error was comparable to glass lenses.

Quantitative evaluation of performance of 3D printed lenses

PubMed Central

Gawedzinski, John; Pawlowski, Michal E.; Tkaczyk, Tomasz S.

2017-01-01

We present an analysis of the shape, surface quality, and imaging capabilities of custom 3D printed lenses. 3D printing technology enables lens prototypes to be fabricated without restrictions on surface geometry. Thus, spherical, aspherical and rotationally non-symmetric lenses can be manufactured in an integrated production process. This technique serves as a noteworthy alternative to multistage, labor-intensive, abrasive processes such as grinding, polishing and diamond turning. Here, we evaluate the quality of lenses fabricated by Luxexcel using patented Printoptical© technology that is based on an inkjet printing technique by comparing them to lenses made with traditional glass processing technologies (grinding, polishing etc.). The surface geometry and roughness of the lenses were evaluated using white-light and Fizeau interferometers. We have compared peak-to-valley wavefront deviation, root-mean-squared wavefront error, radii of curvature and the arithmetic average of the roughness profile (Ra) of plastic and glass lenses. Additionally, the imaging performance of selected pairs of lenses was tested using 1951 USAF resolution target. The results indicate performance of 3D printed optics that could be manufactured with surface roughness comparable to that of injection molded lenses (Ra < 20 nm). The RMS wavefront error of 3D printed prototypes was at a minimum 18.8 times larger than equivalent glass prototypes for a lens with a 12.7 mm clear aperture, but when measured within 63% of its clear aperture, 3D printed components’ RMS wavefront error was comparable to glass lenses. PMID:29238114

Advances in the Lightweight Air-Liquid Composite Heat Exchanger Development for Space Exploration Applications

NASA Technical Reports Server (NTRS)

Shin, E. Eugene; Johnston, J. Chris; Haas, Daniel

2011-01-01

An advanced, lightweight composite modular Air/Liquid (A/L) Heat Exchanger (HX) Prototype for potential space exploration thermal management applications was successfully designed, manufactured, and tested. This full-scale Prototype consisting of 19 modules, based on recommendations from its predecessor Engineering Development unit (EDU) but with improved thermal characteristics and manufacturability, was 11.2 % lighter than the EDU and achieves potentially a 42.7% weight reduction from the existing state-of-the-art metallic HX demonstrator. However, its higher pressure drop (0.58 psid vs. 0.16 psid of the metal HX) has to be mitigated by foam material optimizations and design modifications including a more systematic air channel design. Scalability of the Prototype design was validated experimentally by comparing manufacturability and performance between the 2-module coupon and the 19-module Prototype. The Prototype utilized the thermally conductive open-cell carbon foam material but with lower density and adopted a novel high-efficiency cooling system with significantly increased heat transfer contact surface areas, improved fabricability and manufacturability compared to the EDU. Even though the Prototype was required to meet both the thermal and the structural specifications, accomplishing the thermal requirement was a higher priority goal for this first version. Overall, the Prototype outperformed both the EDU and the corresponding metal HX, particularly in terms of specific heat transfer, but achieved 93.4% of the target. The next generation Prototype to achieve the specification target, 3,450W would need 24 core modules based on the simple scaling factor. The scale-up Prototype will weigh about 14.7 Kg vs. 21.6 Kg for the metal counterpart. The advancement of this lightweight composite HX development from the original feasibility test coupons to EDU to Prototype is discussed in this paper.

Influence of slip-surface geometry on earth-flow deformation, Montaguto earth flow, southern Italy

USGS Publications Warehouse

Guerriero, L.; Coe, Jeffrey A.; Revellio, P.; Grelle, G.; Pinto, F.; Guadagno, F.

2016-01-01

We investigated relations between slip-surface geometry and deformational structures and hydrologic features at the Montaguto earth flow in southern Italy between 1954 and 2010. We used 25 boreholes, 15 static cone-penetration tests, and 22 shallow-seismic profiles to define the geometry of basal- and lateral-slip surfaces; and 9 multitemporal maps to quantify the spatial and temporal distribution of normal faults, thrust faults, back-tilted surfaces, strike-slip faults, flank ridges, folds, ponds, and springs. We infer that the slip surface is a repeating series of steeply sloping surfaces (risers) and gently sloping surfaces (treads). Stretching of earth-flow material created normal faults at risers, and shortening of earth-flow material created thrust faults, back-tilted surfaces, and ponds at treads. Individual pairs of risers and treads formed quasi-discrete kinematic zones within the earth flow that operated in unison to transmit pulses of sediment along the length of the flow. The locations of strike-slip faults, flank ridges, and folds were not controlled by basal-slip surface topography but were instead dependent on earth-flow volume and lateral changes in the direction of the earth-flow travel path. The earth-flow travel path was strongly influenced by inactive earth-flow deposits and pre-earth-flow drainages whose positions were determined by tectonic structures. The implications of our results that may be applicable to other earth flows are that structures with strikes normal to the direction of earth-flow motion (e.g., normal faults and thrust faults) can be used as a guide to the geometry of basal-slip surfaces, but that depths to the slip surface (i.e., the thickness of an earth flow) will vary as sediment pulses are transmitted through a flow.

Experimental validation of an ultrasonic flowmeter for unsteady flows

NASA Astrophysics Data System (ADS)

Leontidis, V.; Cuvier, C.; Caignaert, G.; Dupont, P.; Roussette, O.; Fammery, S.; Nivet, P.; Dazin, A.

2018-04-01

An ultrasonic flowmeter was developed for further applications in cryogenic conditions and for measuring flow rate fluctuations in the range of 0 to 70 Hz. The prototype was installed in a flow test rig, and was validated experimentally both in steady and unsteady water flow conditions. A Coriolis flowmeter was used for the calibration under steady state conditions, whereas in the unsteady case the validation was done simultaneously against two methods: particle image velocimetry (PIV), and with pressure transducers installed flush on the wall of the pipe. The results show that the developed flowmeter and the proposed methodology can accurately measure the frequency and amplitude of unsteady fluctuations in the experimental range of 0-9 l s-1 of the mean main flow rate and 0-70 Hz of the imposed disturbances.

Description and field test of an in situ coliform monitoring system

NASA Technical Reports Server (NTRS)

Grana, D. C.; Wilkins, J. R.

1979-01-01

A prototype in situ system for monitoring the levels of fecal coliforms in shallow water bodies was developed and evaluated. This system was based on the known relationship between the concentration of the coliform bacteria and the amount of hydrogen they produce during growth in a complex organic media. The prototype system consists of a sampler platform, which sits on the bottom; a surface buoy, which transmits sampler-generated data; and a shore station, which receives, displays the data, and controls the sampler. The concept of remote monitoring of fecal coliform concentrations by utilizing a system based on the electrochemical method was verified during the evaluation of the prototype.

Two-Dimensional and Three-Dimensional Ultrasound of Artificial Skin.

PubMed

Wortsman, Ximena; Navarrete, Nelson

2017-01-01

Wound healing may be a difficult problem, and variable types of artificial skin prototypes have been developed for supporting this process. Using ultrasound, we studied 4 cellulose-derived artificial skin prototypes and assessed their two-dimensional and three-dimensional morphology. These prototypes were identified on ultrasound both on in vitro and in vivo studies. They allowed the sonographic observation of deeper layers on different types of surfaces of the body with good definition on the in vivo examinations performed on healthy skin and cutaneous ulcers. The ultrasound detection of these artificial biomaterials may potentially support the noninvasive monitoring of wound healing. © 2016 by the American Institute of Ultrasound in Medicine.

An Insoluble Titanium-Lead Anode for Sulfate Electrolytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferdman, Alla

2005-05-11

The project is devoted to the development of novel insoluble anodes for copper electrowinning and electrolytic manganese dioxide (EMD) production. The anodes are made of titanium-lead composite material produced by techniques of powder metallurgy, compaction of titanium powder, sintering and subsequent lead infiltration. The titanium-lead anode combines beneficial electrochemical behavior of a lead anode with high mechanical properties and corrosion resistance of a titanium anode. In the titanium-lead anode, the titanium stabilizes the lead, preventing it from spalling, and the lead sheathes the titanium, protecting it from passivation. Interconnections between manufacturing process, structure, composition and properties of the titanium-lead compositemore » material were investigated. The material containing 20-30 vol.% of lead had optimal combination of mechanical and electrochemical properties. Optimal process parameters to manufacture the anodes were identified. Prototypes having optimized composition and structure were produced for testing in operating conditions of copper electrowinning and EMD production. Bench-scale, mini-pilot scale and pilot scale tests were performed. The test anodes were of both a plate design and a flow-through cylindrical design. The cylindrical anodes were composed of cylinders containing titanium inner rods and fitting over titanium-lead bushings. The cylindrical design allows the electrolyte to flow through the anode, which enhances diffusion of the electrolyte reactants. The cylindrical anodes demonstrate higher mass transport capabilities and increased electrical efficiency compared to the plate anodes. Copper electrowinning represents the primary target market for the titanium-lead anode. A full-size cylindrical anode performance in copper electrowinning conditions was monitored over a year. The test anode to cathode voltage was stable in the 1.8 to 2.0 volt range. Copper cathode morphology was very smooth and uniform. There was no measurable anode weight loss during this time period. Quantitative chemical analysis of the anode surface showed that the lead content after testing remained at its initial level. No lead dissolution or transfer from the anode to the product occurred.A key benefit of the titanium-lead anode design is that cobalt additions to copper electrolyte should be eliminated. Cobalt is added to the electrolyte to help stabilize the lead oxide surface of conventional lead anodes. The presence of the titanium intimately mixed with the lead should eliminate the need for cobalt stabilization of the lead surface. The anode should last twice as long as the conventional lead anode. Energy savings should be achieved due to minimizing and stabilizing the anode-cathode distance in the electrowinning cells. The anode is easily substitutable into existing tankhouses without a rectifier change.The copper electrowinning test data indicate that the titanium-lead anode is a good candidate for further testing as a possible replacement for a conventional lead anode. A key consideration is the cost. Titanium costs have increased. One of the ways to get the anode cost down is manufacturing the anodes with fewer cylinders. Additional prototypes having different number of cylinders were constructed for a long-term commercial testing in a circuit without cobalt. The objective of the testing is to evaluate the need for cobalt, investigate the effect of decreasing the number of cylinders on the anode performance, and to optimize further the anode design in order to meet the operating requirements, minimize the voltage, maximize the life of the anode, and to balance this against a reasonable cost for the anode. It is anticipated that after testing of the additional prototypes, a whole cell commercial test will be conducted to complete evaluation of the titanium-lead anode costs/benefits.« less

Development of a Test to Evaluate Aerothermal Response of Materials to Hypersonic Flow Using a Scramjet Wind Tunnel (Postprint)

DTIC Science & Technology

2010-05-01

SCRAMJET WIND TUNNEL (POSTPRINT) 5a. CONTRACT NUMBER FA8650-10-D-5226-0002 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6. AUTHOR(S...prototype scramjet engine as a wind tunnel . A sample holder was designed using combustion fluid dynamics results as inputs into structural models. The...Z39-18 Development of a Test to Evaluate Aerothermal Response of Materials to Hypersonic Flow Using a Scramjet Wind Tunnel Triplicane A

Asia Pacific Research Initiative for Sustainable Energy Systems 2011 (APRISES11)

DTIC Science & Technology

2017-09-29

created during a single run , highlighting rapid prototyping capabilities. NRL’s overall goal was to evaluate whether 3D printed metallic bipolar plates...varying the air flow to evaluate the effect on peak power. These runs are displayed in Figure 2.1.17. The reactants were connected in co-flow with the...way valve allows the operator to either run the gas through a humidifier (PermaPure Model FCl 25-240-7) or a bypass loop. On the humidifier side of

Two-Phase Flow Instrumentation Review Group Meeting. Proceedings of Meeting Held in Silver Spring, Maryland on January 13-14, 1977

DTIC Science & Technology

1978-03-01

ADWRESS OInclud Zip Code) 10. PROJECTfTASK/WORK UNI1 VO. Same as 9. above. I1. CONTRACT NO. 13. TYPE OF REPORT PERIOD COVERED (inclusive dews ) Meeting...Discussion of basic principles. c. Lists of y-emitling tracers for gas ; for liquid; commercially available radioisotope milking systems; elements easily...factors) - single phase loops, full flow, (2) prototype calibration (a) gas -water loop, (b) geometry effect. (c) scaling. (3) proof testing - simulation of

The Development and Design of a Prototype Ultra High Pressure P-19 Firefighting Vehicle

DTIC Science & Technology

2007-02-03

the energizing affects of a delivery pressure 4 times (approximately 1200 psi) the magnitude of the standard system at the bumper turret nozzle...permanently extinguish a fire. The onboard CAF system is capable of 300 gpm delivery of foam at approximately 165 psi out of the bumper turret, and a...hand line flowing 45 gpm at approximately 165 psi also. The dry chemical system is designed to flow approximately 7 pps from the bumper turret, and 5

An Electrostatic Precipitator System for the Martian Environment

NASA Technical Reports Server (NTRS)

Calle, C. I.; Mackey, P. J.; Hogue, M. D.; Johansen, M. R.; Phillips, J. R., III; Clements, J. S.

2012-01-01

Human exploration missions to Mars will require the development of technologies for the utilization of the planet's own resources for the production of commodities. However, the Martian atmosphere contains large amounts of dust. The extraction of commodities from this atmosphere requires prior removal of this dust. We report on our development of an electrostatic precipitator able to collect Martian simulated dust particles in atmospheric conditions approaching those of Mars. Extensive experiments with an initial prototype in a simulated Martian atmosphere showed efficiencies of 99%. The design of a second prototype with aerosolized Martian simulated dust in a flow-through is described. Keywords: Space applications, electrostatic precipitator, particle control, particle charging

Development of an Opto-Acoustic Recanalization System Final Report CRADA No. 1314-96

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silva, L. D.; Adam, H. R.

The objective of the project was to develop an ischemic stroke treatient system that restores blood flow to the brain by removing occlusions using acoustic energy created by fiber optic delivery of laser light, a process called Opto Acoustic Recanalization (OAR). The key tasks of the project were to select a laser system, quantify temperature, pressure and particle size distribution, and develop a prototype device incorporating a feedback mechanism. System parameters were developed to cause emulsification while attempting to minimize particle size and collateral damage. The prototype system was tested in animal models and resulted in no visible collateral damage.

The application of ionizers in domestic refrigerators for reduction in airborne and surface bacteria.

PubMed

Kampmann, Y; Klingshirn, A; Kloft, K; Kreyenschmidt, J

2009-12-01

To investigate the antimicrobial effect of ionization on bacteria in household refrigerators. Ionizer prototypes were tested with respect to their technical requirements and their ability to reduce surface and airborne contamination in household refrigerators. Ion and ozone production of the tested prototypes were measured online by an ion meter and an ozone analyser. The produced negative air ion (NAI) and ozone amounts were between 1.2 and 3.7 x 10(6) NAI cm(-3) and 11 and 19 ppb O(3), respectively. To test the influence of ionization on surface contamination, different materials like plastic, glass and nutrient agar for simulation of food were inoculated with bacterial suspensions. The reduction rate was dependent on surface properties. The effect on airborne bacteria was tested by nebulization of Bacillus subtilis- suspension (containing spores) aerosols in refrigerators with and without an ionizer. A clear reduction in air contamination because of ionization was measured. The antimicrobial effect is dependent on several factors, such as surface construction and airflow patterns within the refrigerator. Ionization seems to be an effective method for reduction in surface and airborne bacteria. This study is an initiation for a new consumer tool to decontaminate domestic refrigerators.

Estimating AADT from combined air photos and ground based data : system design, prototyping, and testing.

DOT National Transportation Integrated Search

2009-09-15

Average annual daily traffic (AADT) is perhaps the most fundamental measure of traffic flow. The data used to produce AADT estimates are largely collected by in-highway traffic counters operated by traffic monitoring crews who must cover thousands of...

Development of a prototype vehicle-infrastructure integration system for real-time traffic management.

DOT National Transportation Integrated Search

2008-08-01

Freeway congestion is a major problem in many urban areas. It has been estimated that freeway incidents (events that impede the flow of traffic: accidents, disabled vehicles, etc.) account for one-half to three-fourths of the total congestion on metr...

Initial development of high-accuracy CFRP panel for DATE5 antenna

NASA Astrophysics Data System (ADS)

Qian, Yuan; Lou, Zheng; Hao, Xufeng; Zhu, Jing; Cheng, Jingquan; Wang, Hairen; Zuo, Yingxi; Yang, Ji

2016-07-01

DATE5 antenna, which is a 5m telescope for terahertz exploration, will be sited at Dome A, Antarctica. It is necessary to keep high surface accuracy of the primary reflector panels so that high observing efficiency can be achieved. In antenna field, carbon fiber reinforced composite (CFRP) sandwich panels are widely used as these panels are light in weight, high in strength, low in thermal expansion, and cheap in mass fabrication. In DATE5 project, CFRP panels are important panel candidates. In the design study phase, a CFRP prototype panel of 1-meter size is initially developed for the verification purpose. This paper introduces the material arrangement in the sandwich panel, measured performance of this testing sandwich structure samples, and together with the panel forming process. For anti-icing in the South Pole region, a special CFRP heating film is embedded in the front skin of sandwich panel. The properties of some types of basic building materials are tested. Base on the results, the deformation of prototype panel with different sandwich structures and skin layers are simulated and a best structural concept is selected. The panel mold used is a high accuracy one with a surface rms error of 1.4 μm. Prototype panels are replicated from the mold. Room temperature curing resin is used to reduce the thermal deformation in the resin transfer process. In the curing, vacuum negative pressure technology is also used to increase the volume content of carbon fiber. After the measurement of the three coordinate measure machine (CMM), a prototype CFRP panel of 5.1 μm rms surface error is developed initially.

An integrated array of microfluidic oxygenators as a neonatal lung assist device: in vitro characterization and in vivo demonstration.

PubMed

Rochow, Niels; Manan, Asmaa; Wu, Wen-I; Fusch, Gerhard; Monkman, Shelley; Leung, Jennifer; Chan, Emily; Nagpal, Dipen; Predescu, Dragos; Brash, John; Selvaganapathy, Ponnambalam Ravi; Fusch, Christoph

2014-10-01

A miniaturized oxygenator device that is perfused like an artificial placenta via the umbilical vessels may have significant potential to save the lives of newborns with respiratory insufficiency. Recently we presented the concept of an integrated modular lung assist device (LAD) that consists of stacked microfluidic single oxygenator units (SOUs) and demonstrated the technical details and operation of SOU prototypes. In this article, we present a LAD prototype that is designed to accommodate the different needs of term and preterm infants by permitting changing of the number of parallel-stacked microfluidic SOUs according to the actual body weight. The SOUs are made of polydimethylsiloxane, arranged in parallel, and connected though 3D-printed polymeric interconnects to form the LAD. The flow characteristics and the gas exchange properties were tested in vitro using human blood. We found that the pressure drop of the LAD increased linearly with flow rate. Gas exchange rates of 2.4-3.8 μL/min/cm(2) (0.3-0.5 mL/kg/min) and 6.4-10.1 μL/min/cm(2) (0.8-1.3 mL/kg/min) for O2 and CO2 , respectively, were achieved. We also investigated protein adsorption to provide preliminary information on the need for application of anticoagulant coating of LAD materials. Albumin adsorption, as measured by gold staining, showed that surface uptake was evenly distributed and occurred at the monolayer level (>0.2 μg/cm(2) ). Finally, we also tested the LAD under in vivo conditions using a newborn piglet model (body weight 1.65-2.0 kg). First, the effect of an arteriovenous bypass via a carotid artery-to-jugular vein shortcut on heart rate and blood pressure was investigated. Heart rate and mean arterial blood pressure remained stable for extracorporeal flow rates of up to 61 mL/kg/min (101 mL/min). Next, the LAD was connected to umbilical vessels (maximum flow rate of 24 mL/min [10.4 mL/kg/min]), and O2 gas exchange was measured under hypoxic conditions (Fi O2  = 0.15) and was found to be 3.0 μL/min/cm(2) . These results are encouraging and support the feasibility of an artificial placental design for an LAD. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Effects of rainfall patterns and land cover on the subsurface flow generation of sloping Ferralsols in southern China

PubMed Central

Yang, Jie; Tang, Chongjun; Chen, Lihua; Liu, Yaojun; Wang, Lingyun

2017-01-01

Rainfall patterns and land cover are two important factors that affect the runoff generation process. To determine the surface and subsurface flows associated with different rainfall patterns on sloping Ferralsols under different land cover types, observational data related to surface and subsurface flows from 5 m × 15 m plots were collected from 2010 to 2012. The experiment was conducted to assess three land cover types (grass, litter cover and bare land) in the Jiangxi Provincial Soil and Water Conservation Ecological Park. During the study period, 114 natural rainfall events produced subsurface flow and were divided into four groups using k-means clustering according to rainfall duration, rainfall depth and maximum 30-min rainfall intensity. The results showed that the total runoff and surface flow values were highest for bare land under all four rainfall patterns and lowest for the covered plots. However, covered plots generated higher subsurface flow values than bare land. Moreover, the surface and subsurface flows associated with the three land cover types differed significantly under different rainfall patterns. Rainfall patterns with low intensities and long durations created more subsurface flow in the grass and litter cover types, whereas rainfall patterns with high intensities and short durations resulted in greater surface flow over bare land. Rainfall pattern I had the highest surface and subsurface flow values for the grass cover and litter cover types. The highest surface flow value and lowest subsurface flow value for bare land occurred under rainfall pattern IV. Rainfall pattern II generated the highest subsurface flow value for bare land. Therefore, grass or litter cover are able to convert more surface flow into subsurface flow under different rainfall patterns. The rainfall patterns studied had greater effects on subsurface flow than on total runoff and surface flow for covered surfaces, as well as a greater effect on surface flows associated with bare land. PMID:28792507

LDV measurement of boundary layer on rotating blade surface in wind tunnel

NASA Astrophysics Data System (ADS)

Maeda, Takao; Kamada, Yasunari; Murata, Junsuke; Suzuki, Daiki; Kaga, Norimitsu; Kagisaki, Yosuke

2014-12-01

Wind turbines generate electricity due to extracting energy from the wind. The rotor aerodynamics strongly depends on the flow around blade. The surface flow on the rotating blade affects the sectional performance. The wind turbine surface flow has span-wise component due to span-wise change of airfoil section, chord length, twisted angle of blade and centrifugal force on the flow. These span-wise flow changes the boundary layer on the rotating blade and the sectional performance. Hence, the thorough understanding of blade surface flow is important to improve the rotor performance. For the purpose of clarification of the flow behaviour around the rotor blade, the velocity in the boundary layer on rotating blade surface of an experimental HAWT was measured in a wind tunnel. The velocity measurement on the blade surface was carried out by a laser Doppler velocimeter (LDV). As the results of the measurement, characteristics of surface flow are clarified. In optimum tip speed operation, the surface flow on leading edge and r/R=0.3 have large span-wise velocity which reaches 20% of sectional inflow velocity. The surface flow inboard have three dimensional flow patterns. On the other hand, the flow outboard is almost two dimensional in cross sectional plane.

Granular flows in constrained geometries

NASA Astrophysics Data System (ADS)

Murthy, Tejas; Viswanathan, Koushik

Confined geometries are widespread in granular processing applications. The deformation and flow fields in such a geometry, with non-trivial boundary conditions, determine the resultant mechanical properties of the material (local porosity, density, residual stresses etc.). We present experimental studies of deformation and plastic flow of a prototypical granular medium in different nontrivial geometries- flat-punch compression, Couette-shear flow and a rigid body sliding past a granular half-space. These geometries represent simplified scaled-down versions of common industrial configurations such as compaction and dredging. The corresponding granular flows show a rich variety of flow features, representing the entire gamut of material types, from elastic solids (beam buckling) to fluids (vortex-formation, boundary layers) and even plastically deforming metals (dead material zone, pile-up). The effect of changing particle-level properties (e.g., shape, size, density) on the observed flows is also explicitly demonstrated. Non-smooth contact dynamics particle simulations are shown to reproduce some of the observed flow features quantitatively. These results showcase some central challenges facing continuum-scale constitutive theories for dynamic granular flows.

Contraction driven flow in the extended vein networks of Physarum polycephalum

NASA Astrophysics Data System (ADS)

Alim, Karen; Amselem, Gabriel; Peaudecerf, Francois; Pringle, Anne; Brenner, Michael P.

2011-11-01

The true slime mold Physarum polycephalum is a basal organism that forms an extended network of veins to forage for food. P. polycephalum is renown for its adaptive changes of vein structure and morphology in response to food sources. These rearrangements presumably occur to establish an efficient transport and mixing of resources throughout the networks thus presenting a prototype to design transport networks under the constraints of laminar flow. The physical flows of cytoplasmic fluid enclosed by the veins exhibit an oscillatory flow termed ``shuttle streaming.'' The flow exceed by far the volume required for growth at the margins suggesting that the additional energy cost for generating the flow is spent for efficient and/or targeted redistribution of resources. We show that the viscous shuttle flow is driven by the radial contractions of the veins that accompany the streaming. We present a model for the fluid flow and resource dispersion arising due to radial contractions. The transport and mixing properties of the flow are discussed.

Preliminary Feasibility Testing of the BRIC Brine Water Recovery Concept

NASA Technical Reports Server (NTRS)

Callahan, Michael R.; Pensinger, Stuart J.; Pickering, Karen D.

2012-01-01

The Brine Residual In-Containment (BRIC) concept is being developed as a new technology to recover water from spacecraft wastewater brines. Such capability is considered critical to closing the water loop and achieving a sustained human presence in space. The intention of the BRIC concept is to increase the robustness and efficiency of the dewatering process by performing drying inside the container used for the final disposal of the residual brine solid. Recent efforts in the development of BRIC have focused on preliminary feasibility testing using a laboratory- assembled pre-prototype unit. Observations of the drying behavior of actual brine solutions processed under BRIC-like conditions has been of particular interest. To date, experiments conducted with three types of analogue spacecraft wastewater brines have confirmed the basic premise behind the proposed application of in-place drying. Specifically, the dried residual mass from these solutions have tended to exhibit characteristics of adhesion and flow that are expected to continue to challenge process stream management designs typically used in spacecraft systems. Yet, these same characteristics may favor the development of capillary- and surface-tension-based approaches currently envisioned as part of an ultimate microgravity-compatible BRIC design. In addition, preliminary feasibility testing of the BRIC pre-prototype confirmed that high rates of water recovery, up to 98% of the available brine water, may be possible while still removing the majority of the brine contaminants from the influent brine stream. These and other early observations from testing are reported.

Preliminary Feasibility Testing of the BRIC Brine Water Recovery Concept

NASA Technical Reports Server (NTRS)

Callahan, Michael R.; Pensinger, Stuart; Pickering, Karen D.

2011-01-01

The Brine Residual In-Containment (BRIC) concept was developed as a new technology to recover water from spacecraft wastewater brines. Such capability is considered critical to closing the water loop and achieving a sustained human presence in space. The intention of the BRIC concept is to increase the robustness and efficiency of the dewatering process by performing drying inside the container used for the final disposal of the residual brine solid. Recent efforts in the development of BRIC have focused on preliminary feasibility testing using a laboratory- assembled pre-prototype unit. Observations of the drying behavior of actual brine solutions processed under BRIC-like conditions has been of particular interest. To date, experiments conducted with three types of analogue spacecraft wastewater brines have confirmed the basic premise behind the proposed application of in-place drying for these solutions. Specifically, the dried residual mass from these solutions have tended to exhibit characteristics of adhesion and flow that are expected to continue to challenge process stream management in spacecraft brine dewatering system designs. Yet, these same characteristics may favor the development of capillary- and surface-tension-based approaches envisioned as part of an ultimate microgravity-compatible BRIC design. In addition, preliminary feasibility testing of the BRIC pre-prototype confirmed that high rates of water recovery, up to 98% of the available brine water, may be possible while still removing the majority of the brine contaminants from the influent brine stream. These and other observations from testing are reported.

Cost-effective rapid prototyping and assembly of poly(methyl methacrylate) microfluidic devices.

PubMed

Matellan, Carlos; Del Río Hernández, Armando E

2018-05-03

The difficulty in translating conventional microfluidics from laboratory prototypes to commercial products has shifted research efforts towards thermoplastic materials for their higher translational potential and amenability to industrial manufacturing. Here, we present an accessible method to fabricate and assemble polymethyl methacrylate (PMMA) microfluidic devices in a "mask-less" and cost-effective manner that can be applied to manufacture a wide range of designs due to its versatility. Laser micromachining offers high flexibility in channel dimensions and morphology by controlling the laser properties, while our two-step surface treatment based on exposure to acetone vapour and low-temperature annealing enables improvement of the surface quality without deformation of the device. Finally, we demonstrate a capillarity-driven adhesive delivery bonding method that can produce an effective seal between PMMA devices and a variety of substrates, including glass, silicon and LiNbO 3 . We illustrate the potential of this technique with two microfluidic devices, an H-filter and a droplet generator. The technique proposed here offers a low entry barrier for the rapid prototyping of thermoplastic microfluidics, enabling iterative design for laboratories without access to conventional microfabrication equipment.

Studies of fluid instabilities in flows of lava and debris

NASA Technical Reports Server (NTRS)

Fink, Jonathan H.

1987-01-01

At least two instabilities have been identified and utilized in lava flow studies: surface folding and gravity instability. Both lead to the development of regularly spaced structures on the surfaces of lava flows. The geometry of surface folds have been used to estimate the rheology of lava flows on other planets. One investigation's analysis assumed that lava flows have a temperature-dependent Newtonian rheology, and that the lava's viscosity decreased exponentially inward from the upper surface. The author reviews studies by other investigators on the analysis of surface folding, the analysis of Taylor instability in lava flows, and the effect of surface folding on debris flows.

Plasma Interactions With Spacecraft (I)

DTIC Science & Technology

2009-04-01

with the Windows, Red hat LINUX, and MacOS X environments. We wrote N2kScriptRunner, a C++ code that runs a Nascap-2k script outside of the Java ...console-based and with a Java interface), a stand alone program that reads and writes Nascap-2k database files. This program has proved invaluable...surface currents for DSX and prototyped it in Java . A description of the algorithm and the prototype implementation is in Section 3. 1.5. DSX

Human Fitting Studies of Cleveland Clinic Continuous-Flow Total Artificial Heart

PubMed Central

Karimov, Jamshid H.; Steffen, Robert J.; Byram, Nicole; Sunagawa, Gengo; Horvath, David; Cruz, Vincent; Golding, Leonard A.R.; Fukamachi, Kiyotaka; Moazami, Nader

2015-01-01

Implantation of mechanical circulatory support devices is challenging, especially in patients with a small chest cavity. We evaluated how well the Cleveland Clinic continuous-flow total artificial heart (CFTAH) fit the anatomy of patients about to receive a heart transplant. A mock pump model of the CFTAH was rapid-prototyped using biocompatible materials. The model was brought to the operative table, and the direction, length, and angulation of the inflow/outflow ports and outflow conduits were evaluated after the recipient's ventricles had been resected. Thoracic cavity measurements were based on preoperative computed tomographic data. The CFTAH fit well in all five patients (height, 170 ± 9 cm; weight, 75 ± 24 kg). Body surface area was 1.9 ± 0.3 m2 (range, 1.6-2.1 m2). The required inflow and outflow port orientation of both the left and right housings appeared consistent with the current version of the CFTAH implanted in calves. The left outflow conduit remained straight, but the right outflow direction necessitated a 73 ± 22 degree angulation to prevent potential kinking when crossing over the connected left outflow. These data support the fact that our design achieves the proper anatomical relationship of the CFTAH to a patient's native vessels. PMID:25806613

Examination of the effect of blowing on the near-surface flow structure over a dimpled surface

NASA Astrophysics Data System (ADS)

Borchetta, C. G.; Martin, A.; Bailey, S. C. C.

2018-03-01

The near surface flow over a dimpled surface with flow injection through it was documented using time-resolved particle image velocimetry. The instantaneous flow structure, time-averaged statistics, and results from snapshot proper orthogonal decomposition were used to examine the coherent structures forming near the dimpled surface. In particular, the modifications made to the flow structures by the addition of flow injection through the surface were studied. It was observed that without flow injection, inclined flow structures with alternating vorticity from neighboring dimples are generated by the dimples and advect downstream. This behavior is coupled with fluid becoming entrained inside the dimples, recirculating and ejecting away from the surface. When flow injection was introduced through the surface, the flow structures became more disorganized, but some of the features of the semi-periodic structures observed without flow injection were preserved. The structures with flow injection appear in multiple wall-normal layers, formed from vortical structures shed from upstream dimples, with a corresponding increase in the size of the advecting structures. As a result of the more complex flow field observed with flow injection, there was an increase in turbulent kinetic energy and Reynolds shear stress, with the Reynolds shear stress representing an increase in vertical transport of momentum by sweeping and ejecting motions that were not present without flow injection.

Materials for microfluidic chip fabrication.

PubMed

Ren, Kangning; Zhou, Jianhua; Wu, Hongkai

2013-11-19

Through manipulating fluids using microfabricated channel and chamber structures, microfluidics is a powerful tool to realize high sensitive, high speed, high throughput, and low cost analysis. In addition, the method can establish a well-controlled microenivroment for manipulating fluids and particles. It also has rapid growing implementations in both sophisticated chemical/biological analysis and low-cost point-of-care assays. Some unique phenomena emerge at the micrometer scale. For example, reactions are completed in a shorter amount of time as the travel distances of mass and heat are relatively small; the flows are usually laminar; and the capillary effect becomes dominant owing to large surface-to-volume ratios. In the meantime, the surface properties of the device material are greatly amplified, which can lead to either unique functions or problems that we would not encounter at the macroscale. Also, each material inherently corresponds with specific microfabrication strategies and certain native properties of the device. Therefore, the material for making the device plays a dominating role in microfluidic technologies. In this Account, we address the evolution of materials used for fabricating microfluidic chips, and discuss the application-oriented pros and cons of different materials. This Account generally follows the order of the materials introduced to microfluidics. Glass and silicon, the first generation microfluidic device materials, are perfect for capillary electrophoresis and solvent-involved applications but expensive for microfabriaction. Elastomers enable low-cost rapid prototyping and high density integration of valves on chip, allowing complicated and parallel fluid manipulation and in-channel cell culture. Plastics, as competitive alternatives to elastomers, are also rapid and inexpensive to microfabricate. Their broad variety provides flexible choices for different needs. For example, some thermosets support in-situ fabrication of arbitrary 3D structures, while some perfluoropolymers are extremely inert and antifouling. Chemists can use hydrogels as highly permeable structural material, which allows diffusion of molecules without bulk fluid flows. They are used to support 3D cell culture, to form diffusion gradient, and to serve as actuators. Researchers have recently introduced paper-based devices, which are extremely low-cost to prepare and easy to use, thereby promising in commercial point-of-care assays. In general, the evolution of chip materials reflects the two major trends of microfluidic technology: powerful microscale research platforms and low-cost portable analyses. For laboratory research, chemists choosing materials generally need to compromise the ease in prototyping and the performance of the device. However, in commercialization, the major concerns are the cost of production and the ease and reliability in use. There may be new growth in the combination of surface engineering, functional materials, and microfluidics, which is possibly accomplished by the utilization of composite materials or hybrids for advanced device functions. Also, significant expanding of commercial applications can be predicted.

CRLH-TL Sensors for Flow Inhomogeneties Detection of Pneumatic Conveyed Pulverized Solids

NASA Astrophysics Data System (ADS)

Angelovski, Aleksandar; Penirschke, Andreas; Jakoby, Rolf

2011-08-01

This paper presents an application of a Composite Right/Left-Handed (CRLH) Transmission Line resonator for a compact mass flow detector which is able to detect inhomogeneous flows. In this concept, series capacitors and shunt inductors are used to synthesize a medium with simultaneously negative permeability and permittivity - the so called metamaterial. The helix shape of the cylindrical CRLH-TL sensor offers the possibility to detect flow inhomogeneities within the pipeline which can be used to correct the detected massflow rate. A combination of two CRLH-TL structures within the same cross-section of the pipeline can improve the angular sensitivity of the sensor. A prototype was realized and tested in a dedicated measurement setup to prove the concept.

F-16XL Ship #1 in flight - used for laminar airflow studies

NASA Technical Reports Server (NTRS)

1992-01-01

One of two F-16XL prototype aircraft, on loan from the Air Force, was used by NASA's Dryden Flight Research Center, Edwards, California, in a program to investigate laminar flow technology and help improve the flow of air over an aircraft's wing at sustained supersonic speeds. A small, perforated titanium wing glove with a turbo compressor was tested on the F-16XL to determine if air suction can remove a small part of the boundary-layer air flowing over the wing and thereby achieve laminar (smooth) flow over a portion of the wing. The flight research program on ship #1 ended in 1996. It was then conducted with NASA's two-seat F-16XL, ship #2 employing a larger glove.

Updating the 2001 National Land Cover Database Impervious Surface Products to 2006 using Landsat imagery change detection methods

USGS Publications Warehouse

Xian, George; Homer, Collin G.

2010-01-01

A prototype method was developed to update the U.S. Geological Survey (USGS) National Land Cover Database (NLCD) 2001 to a nominal date of 2006. NLCD 2001 is widely used as a baseline for national land cover and impervious cover conditions. To enable the updating of this database in an optimal manner, methods are designed to be accomplished by individual Landsat scene. Using conservative change thresholds based on land cover classes, areas of change and no-change were segregated from change vectors calculated from normalized Landsat scenes from 2001 and 2006. By sampling from NLCD 2001 impervious surface in unchanged areas, impervious surface predictions were estimated for changed areas within an urban extent defined by a companion land cover classification. Methods were developed and tested for national application across six study sites containing a variety of urban impervious surface. Results show the vast majority of impervious surface change associated with urban development was captured, with overall RMSE from 6.86 to 13.12% for these areas. Changes of urban development density were also evaluated by characterizing the categories of change by percentile for impervious surface. This prototype method provides a relatively low cost, flexible approach to generate updated impervious surface using NLCD 2001 as the baseline.

Generation Mechanism and Prediction Model for Low Frequency Noise Induced by Energy Dissipating Submerged Jets during Flood Discharge from a High Dam

PubMed Central

Lian, Jijian; Zhang, Wenjiao; Guo, Qizhong; Liu, Fang

2016-01-01

As flood water is discharged from a high dam, low frequency (i.e., lower than 10 Hz) noise (LFN) associated with air pulsation is generated and propagated in the surrounding areas, causing environmental problems such as vibrations of windows and doors and discomfort of residents and construction workers. To study the generation mechanisms and key influencing factors of LFN induced by energy dissipation through submerged jets at a high dam, detailed prototype observations and analyses of LFN are conducted. The discharge flow field is simulated using a gas-liquid turbulent flow model, and the vorticity fluctuation characteristics are then analyzed. The mathematical model for the LFN intensity is developed based on vortex sound theory and a turbulent flow model, verified by prototype observations. The model results reveal that the vorticity fluctuation in strong shear layers around the high-velocity submerged jets is highly correlated with the on-site LFN, and the strong shear layers are the main regions of acoustic source for the LFN. In addition, the predicted and observed magnitudes of LFN intensity agree quite well. This is the first time that the LFN intensity has been shown to be able to be predicted quantitatively. PMID:27314374

SUSTAINABLE WATER EXTRACTION AND DISTRIBUTION SYSTEM FOR AGRICULTURAL APPLICATIONS IN NAMAWANGA, KENYA

EPA Science Inventory

In order to ensure that the pumps are successful when installed for the community, working prototypes were tested, analyzed, and modified. The chief concerns of our functional analysis were the flow rate of the pump, the stability/durability of the system, total pumping head, ...

Simulating Retail Banking for Banking Students

ERIC Educational Resources Information Center

Supramaniam, Mahadevan; Shanmugam, Bala

2009-01-01

The purpose of this study was to examine the implementation flow and development of retail bank management simulation based training system which could provide a comprehensive knowledge about the operations and management of banks for the banking students. The prototype of a Retail banking simulation based training system was developed based on…

Advanced Drying Process for Lower Manufacturing Cost of Electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmad, Iftikhar; Zhang, Pu

For this Vehicle Technologies Incubator/Energy Storage R&D topic, Lambda Technologies teamed with Navitas Systems and proposed a new advanced drying process that promised a 5X reduction in electrode drying time and significant reduction in the cost of large format lithium batteries used in PEV's. The operating principle of the proposed process was to use penetrating radiant energy source Variable Frequency Microwaves (VFM), that are selectively absorbed by the polar water or solvent molecules instantly in the entire volume of the electrode. The solvent molecules are thus driven out of the electrode thickness making the process more efficient and much fastermore » than convective drying method. To evaluate the Advanced Drying Process (ADP) a hybrid prototype system utilizing VFM and hot air flow was designed and fabricated. While VFM drives the solvent out of the electrode thickness, the hot air flow exhausts the solvent vapors out of the chamber. The drying results from this prototype were very encouraging. For water based anodes there is a 5X drying advantage (time & length of oven) in using ADP over standard drying system and for the NMP based cathodes the reduction in drying time has 3X benefit. For energy savings the power consumption measurements were performed to ADP prototype and compared with the convection standard drying oven. The data collected demonstrated over 40% saving in power consumption with ADP as compared to the convection drying systems. The energy savings are one of the operational cost benefits possible with ADP. To further speed up the drying process, the ADP prototype was explored as a booster module before the convection oven and for the electrode material being evaluated it was possible to increase the drying speed by a factor of 4, which could not be accomplished with the standard dryer without surface defects and cracks. The instantaneous penetration of microwave in the entire slurry thickness showed a major advantage in rapid drying of the electrode materials. For the existing electrode materials, the material analysis and cell characterization data from ADP dried electrodes showed equivalent (or slightly better) performance. However, for high loading and thicker electrode materials (for high energy densities) the ADP advantages are more prominent. There was less binder migration, the resistance was lower hence the current capacities and retention of the battery cells were higher. The success of the project has enabled credible communications with commercial end users as well as battery coating line integrators. Goal is to scale ADP up for high volume manufacturing of Li-ion battery electrodes. The implementation of ADP in high volume manufacturing will reduce a high cost production step to bring the overall price of Li-ion batteries down. This will ultimately have a positive impact on the public by making electric and hybrid vehicles more affordable.« less

Modernization of vertical Pelton turbines with the help of CFD and model testing

NASA Astrophysics Data System (ADS)

Mack, Reiner; Gola, Bartlomiej; Smertnig, Martin; Wittwer, Bernhard; Meusburger, Peter

2014-03-01

The modernization of water turbines bears a high potential of increasing the already installed hydropower capacity. In many projects the existing waterways allow a substantial increase of the available flow capacity and with it the energy output. But also the upgrading onto a state of the art hydraulic, mechanical and electrical design will increase the available power considerably after the rehabilitation. The two phase nature of the flow in Pelton turbines requires for the hydraulic refurbishment special care in the application of the available design methods. Where the flow in the high pressure section of the turbine is mainly of one phase nature, CFD has been used as a standard tool for many years. Also the jet quality, and with it the exploration of the source of flow disturbances that cause poor free surface quality can be investigated with CFD. The interaction of the jet with the buckets of the runner is also examined by means of CFD. However, its accuracy with respect to hydraulic efficiency is, because of the two phase flow and the transient flow process, in very few cases good enough for a reliable and accurate prediction of absolute numbers. The optimization of hydraulic bucket profiles is therefore always checked with measurements in homologous scaled model turbines. A similar situation exists for the housing flow after the water is discharged from the runner. Here also CFD techniques are available to explore the general mechanisms. However, due to the two phase flow nature, where only a very small space is filled with moving water, the experimental setup in a model turbine is always the final proof for optimizations of housing inserts and modifications. The hydraulic design of a modernization project for a power station equipped with vertical Pelton turbines of two different designs is described in the proposed paper. It will be shown, how CFD is applied to determine the losses in the high pressure section and how these results are combined with the model tests carried out in the hydraulic laboratory. Finally a comparison is made in between the achieved model turbine results with measurements carried out in the prototype.

High–energy density nonaqueous all redox flow lithium battery enabled with a polymeric membrane

PubMed Central

Jia, Chuankun; Pan, Feng; Zhu, Yun Guang; Huang, Qizhao; Lu, Li; Wang, Qing

2015-01-01

Redox flow batteries (RFBs) are considered one of the most promising large-scale energy storage technologies. However, conventional RFBs suffer from low energy density due to the low solubility of the active materials in electrolyte. On the basis of the redox targeting reactions of battery materials, the redox flow lithium battery (RFLB) demonstrated in this report presents a disruptive approach to drastically enhancing the energy density of flow batteries. With LiFePO4 and TiO2 as the cathodic and anodic Li storage materials, respectively, the tank energy density of RFLB could reach ~500 watt-hours per liter (50% porosity), which is 10 times higher than that of a vanadium redox flow battery. The cell exhibits good electrochemical performance under a prolonged cycling test. Our prototype RFLB full cell paves the way toward the development of a new generation of flow batteries for large-scale energy storage. PMID:26702440

Two-phase flow in the cooling circuit of a cryogenic rocket engine

NASA Astrophysics Data System (ADS)

Preclik, D.

1992-07-01

Transient two-phase flow was investigated for the hydrogen cooling circuit of the HM7 rocket engine. The nuclear reactor code ATHLET/THESEUS was adapted to cryogenics and applied to both principal and prototype experiments for validation and simulation purposes. The cooling circuit two-phase flow simulation focused on the hydrogen prechilling and pump transient phase prior to ignition. Both a single- and a multichannel model were designed and employed for a valve leakage flow, a nominal prechilling flow, and a prechilling with a subsequent pump-transient flow. The latter case was performed in order to evaluate the difference between a nominal and a delayed turbo-pump start-up. It was found that an extension of the nominal prechilling sequence in the order of 1 second is sufficient to finally provide for liquid injection conditions of hydrogen which, as commonly known, is undesirable for smooth ignition and engine starting transients.

High-energy density nonaqueous all redox flow lithium battery enabled with a polymeric membrane.

PubMed

Jia, Chuankun; Pan, Feng; Zhu, Yun Guang; Huang, Qizhao; Lu, Li; Wang, Qing

2015-11-01

Redox flow batteries (RFBs) are considered one of the most promising large-scale energy storage technologies. However, conventional RFBs suffer from low energy density due to the low solubility of the active materials in electrolyte. On the basis of the redox targeting reactions of battery materials, the redox flow lithium battery (RFLB) demonstrated in this report presents a disruptive approach to drastically enhancing the energy density of flow batteries. With LiFePO4 and TiO2 as the cathodic and anodic Li storage materials, respectively, the tank energy density of RFLB could reach ~500 watt-hours per liter (50% porosity), which is 10 times higher than that of a vanadium redox flow battery. The cell exhibits good electrochemical performance under a prolonged cycling test. Our prototype RFLB full cell paves the way toward the development of a new generation of flow batteries for large-scale energy storage.

In Vitro Capture of Small Ferrous Particles with a Magnetic Filtration Device Designed for Intravascular Use with Intraarterial Chemotherapy: Proof-of-Concept Study.

PubMed

Mabray, Marc C; Lillaney, Prasheel; Sze, Chia-Hung; Losey, Aaron D; Yang, Jeffrey; Kondapavulur, Sravani; Liu, Derek; Saeed, Maythem; Patel, Anand; Cooke, Daniel; Jun, Young-Wook; El-Sayed, Ivan; Wilson, Mark; Hetts, Steven W

2016-03-01

To establish that a magnetic device designed for intravascular use can bind small iron particles in physiologic flow models. Uncoated iron oxide particles 50-100 nm and 1-5 µm in size were tested in a water flow chamber over a period of 10 minutes without a magnet (ie, control) and with large and small prototype magnets. These same particles and 1-µm carboxylic acid-coated iron oxide beads were likewise tested in a serum flow chamber model without a magnet (ie, control) and with the small prototype magnet. Particles were successfully captured from solution. Particle concentrations in solution decreased in all experiments (P < .05 vs matched control runs). At 10 minutes, concentrations were 98% (50-100-nm particles in water with a large magnet), 97% (50-100-nm particles in water with a small magnet), 99% (1-5-µm particles in water with a large magnet), 99% (1-5-µm particles in water with a small magnet), 95% (50-100-nm particles in serum with a small magnet), 92% (1-5-µm particles in serum with a small magnet), and 75% (1-µm coated beads in serum with a small magnet) lower compared with matched control runs. This study demonstrates the concept of magnetic capture of small iron oxide particles in physiologic flow models by using a small wire-mounted magnetic filter designed for intravascular use. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

Cytometry standards continuum

NASA Astrophysics Data System (ADS)

Leif, Robert C.; Spidlen, Josef; Brinkman, Ryan R.

2008-02-01

Introduction: The International Society for Analytical Cytology, ISAC, is developing a new combined flow and image Analytical Cytometry Standard (ACS). This standard needs to serve both the research and clinical communities. The clinical medicine and clinical research communities have a need to exchange information with hospital and other clinical information systems. Methods: 1) Prototype the standard by creating CytometryML and a RAW format for binary data. 2) Join the ISAC Data Standards Task Force. 3) Create essential project documentation. 4) Cooperate with other groups by assisting in the preparation of the DICOM Supplement 122: Specimen Module and Pathology Service-Object Pair Classes. Results: CytometryML has been created and serves as a prototype and source of experience for the following: the Analytical Cytometry Standard (ACS) 1.0, the ACS container, Minimum Information about a Flow Cytometry Experiment (MIFlowCyt), and Requirements for a Data File Standard Format to Describe Flow Cytometry and Related Analytical Cytology Data. These requirements provide a means to judge the appropriateness of design elements and to develop tests for the final ACS. The requirements include providing the information required for understanding and reproducing a cytometry experiment or clinical measurement, and for a single standard for both flow and digital microscopic cytometry. Schemas proposed by other members of the ISAC Data Standards Task Force (e.g, Gating-ML) have been independently validated and have been integrated with CytometryML. The use of netCDF as an element of the ACS container has been proposed by others and a suggested method of its use is proposed.

State-and-transition prototype model of riparian vegetation downstream of Glen Canyon Dam, Arizona

USGS Publications Warehouse

Ralston, Barbara E.; Starfield, Anthony M.; Black, Ronald S.; Van Lonkhuyzen, Robert A.

2014-01-01

Facing an altered riparian plant community dominated by nonnative species, resource managers are increasingly interested in understanding how to manage and promote healthy riparian habitats in which native species dominate. For regulated rivers, managing flows is one tool resource managers consider to achieve these goals. Among many factors that can influence riparian community composition, hydrology is a primary forcing variable. Frame-based models, used successfully in grassland systems, provide an opportunity for stakeholders concerned with riparian systems to evaluate potential riparian vegetation responses to alternative flows. Frame-based, state-and-transition models of riparian vegetation for reattachment bars, separation bars, and the channel margin found on the Colorado River downstream of Glen Canyon Dam were constructed using information from the literature. Frame-based models can be simple spreadsheet models (created in Microsoft® Excel) or developed further with programming languages (for example, C-sharp). The models described here include seven community states and five dam operations that cause transitions between states. Each model divides operations into growing (April–September) and non-growing seasons (October–March) and incorporates upper and lower bar models, using stage elevation as a division. The inputs (operations) can be used by stakeholders to evaluate flows that may promote dynamic riparian vegetation states, or identify those flow options that may promote less desirable states (for example, Tamarisk [Tamarix sp.] temporarily flooded shrubland). This prototype model, although simple, can still elicit discussion about operational options and vegetation response.

Energy Harvesting from the Stray Electromagnetic Field around the Electrical Power Cable for Smart Grid Applications

PubMed Central

2016-01-01

For wireless sensor node (WSN) applications, this paper presents the harvesting of energy from the stray electromagnetic field around an electrical power line. Inductive and capacitive types of electrodynamic energy harvesters are developed and reported. For the produced energy harvesters, solid core and split-core designs are adopted. The inductive energy harvester comprises a copper wound coil which is produced on a mild steel core. However, the capacitive prototypes comprise parallel, annular discs separated by Teflon spacers. Moreover, for the inductive energy harvesters' wound coil and core, the parametric analysis is also performed. A Teflon housing is incorporated to protect the energy harvester prototypes from the harsh environmental conditions. Among the inductive energy harvesters, prototype-5 has performed better than the other harvesters and produces a maximum rms voltage of 908 mV at the current level of 155 A in the power line. However, at the same current flow, the capacitive energy harvesters produce a maximum rms voltage of 180 mV. The alternating output of the prototype-5 is rectified, and a super capacitor (1 F, 5.5 V) and rechargeable battery (Nickel-Cadmium, 3.8 V) are charged with it. Moreover, with the utilization of a prototype-5, a self-powered wireless temperature sensing and monitoring system for an electrical transformer is also developed and successfully implemented. PMID:27579343

Integrated optical detection of autonomous capillary microfluidic immunoassays:a hand-held point-of-care prototype.

PubMed

Novo, P; Chu, V; Conde, J P

2014-07-15

The miniaturization of biosensors using microfluidics has potential in enabling the development of point-of-care devices, with the added advantages of reduced time and cost of analysis with limits-of-detection comparable to those obtained through traditional laboratory techniques. Interfacing microfluidic devices with the external world can be difficult especially in aspects involving fluid handling and the need for simple sample insertion that avoids special equipment or trained personnel. In this work we present a point-of-care prototype system by integrating capillary microfluidics with a microfabricated photodiode array and electronic instrumentation into a hand-held unit. The capillary microfluidic device is capable of autonomous and sequential fluid flow, including control of the average fluid velocity at any given point of the analysis. To demonstrate the functionality of the prototype, a model chemiluminescence ELISA was performed. The performance of the integrated optical detection in the point-of-care prototype is equal to that obtained with traditional bench-top instrumentation. The photodiode signals were acquired, displayed and processed by a simple graphical user interface using a computer connected to the microcontroller through USB. The prototype performed integrated chemiluminescence ELISA detection in about 15 min with a limit-of-detection of ≈2 nM with an antibody-antigen affinity constant of ≈2×10(7) M(-1). Copyright © 2014 Elsevier B.V. All rights reserved.

Energy Harvesting from the Stray Electromagnetic Field around the Electrical Power Cable for Smart Grid Applications.

PubMed

Khan, Farid Ullah

For wireless sensor node (WSN) applications, this paper presents the harvesting of energy from the stray electromagnetic field around an electrical power line. Inductive and capacitive types of electrodynamic energy harvesters are developed and reported. For the produced energy harvesters, solid core and split-core designs are adopted. The inductive energy harvester comprises a copper wound coil which is produced on a mild steel core. However, the capacitive prototypes comprise parallel, annular discs separated by Teflon spacers. Moreover, for the inductive energy harvesters' wound coil and core, the parametric analysis is also performed. A Teflon housing is incorporated to protect the energy harvester prototypes from the harsh environmental conditions. Among the inductive energy harvesters, prototype-5 has performed better than the other harvesters and produces a maximum rms voltage of 908 mV at the current level of 155 A in the power line. However, at the same current flow, the capacitive energy harvesters produce a maximum rms voltage of 180 mV. The alternating output of the prototype-5 is rectified, and a super capacitor (1 F, 5.5 V) and rechargeable battery (Nickel-Cadmium, 3.8 V) are charged with it. Moreover, with the utilization of a prototype-5, a self-powered wireless temperature sensing and monitoring system for an electrical transformer is also developed and successfully implemented.

Simulation of an active cooling system for photovoltaic modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelhakim, Lotfi

Photovoltaic cells are devices that convert solar radiation directly into electricity. However, solar radiation increases the photovoltaic cells temperature [1] [2]. The temperature has an influence on the degradation of the cell efficiency and the lifetime of a PV cell. This work reports on a water cooling technique for photovoltaic panel, whereby the cooling system was placed at the front surface of the cells to dissipate excess heat away and to block unwanted radiation. By using water as a cooling medium for the photovoltaic solar cells, the overheating of closed panel is greatly reduced without prejudicing luminosity. The water alsomore » acts as a filter to remove a portion of solar spectrum in the infrared band but allows transmission of the visible spectrum most useful for the PV operation. To improve the cooling system efficiency and electrical efficiency, uniform flow rate among the cooling system is required to ensure uniform distribution of the operating temperature of the PV cells. The aims of this study are to develop a 3D thermal model to simulate the cooling and heat transfer in Photovoltaic panel and to recommend a cooling technique for the PV panel. The velocity, pressure and temperature distribution of the three-dimensional flow across the cooling block were determined using the commercial package, Fluent. The second objective of this work is to study the influence of the geometrical dimensions of the panel, water mass flow rate and water inlet temperature on the flow distribution and the solar panel temperature. The results obtained by the model are compared with experimental results from testing the prototype of the cooling device.« less

Wire-Mesh-Based Sorber for Removing Contaminants from Air

NASA Technical Reports Server (NTRS)

Perry, Jay; Roychoudhury, Subir; Walsh, Dennis

2006-01-01

A paper discusses an experimental regenerable sorber for removing CO2 and trace components principally, volatile organic compounds, halocarbons, and NH3 from spacecraft cabin air. This regenerable sorber is a prototype of what is intended to be a lightweight alternative to activated-carbon and zeolite-pellet sorbent beds now in use. The regenerable sorber consists mainly of an assembly of commercially available meshes that have been coated with a specially-formulated washcoat containing zeolites. The zeolites act as the sorbents while the meshes support the zeolite-containing washcoat in a configuration that affords highly effective surface area for exposing the sorbents to flowing air. The meshes also define flow paths characterized by short channel lengths to prevent excessive buildup of flow boundary layers. Flow boundary layer resistance is undesired because it can impede mass and heat transfer. The total weight and volume comparison versus the atmosphere revitalization equipment used onboard the International Space Station for CO2 and trace-component removal will depend upon the design details of the final embodiment. However, the integrated mesh-based CO2 and trace-contaminant removal system is expected to provide overall weight and volume savings by eliminating most of the trace-contaminant control equipment presently used in parallel processing schemes traditionally used for spacecraft. The mesh-based sorbent media enables integrating the two processes within a compact package. For the purpose of regeneration, the sorber can be heated by passing electric currents through the metallic meshes combined with exposure to space vacuum. The minimal thermal mass of the meshes offers the potential for reduced regeneration-power requirements and cycle time required for regeneration compared to regenerable sorption processes now in use.

Quantification of wind flow in the European Mars Simulation Wind Tunnel Facility

NASA Astrophysics Data System (ADS)

Holstein-Rathlou, C.; Merrison, J. P.; Iversen, J. J.; Nornberg, P.

2012-04-01

We present the European Mars Simulation Wind Tunnel facility, a unique prototype facility capable of simulating a wide range of environmental conditions, such as those which can be found at the surface of Earth or Mars. The chamber complements several other large-scale simulation facilities at Aarhus University, Denmark. The facility consists of a 50 m3 environmental chamber capable of operating at low pressure (0.02 - 1000 mbar) and cryogenic temperatures (-130 °C up to +60 °C). This chamber houses a re-circulating wind tunnel capable of generating wind speeds up to 25 m/s and has a dust injection system that can produce suspended particulates (aerosols). It employs a unique LED based optical illumination system (solar simulator) and an advanced network based control system. Laser based optoelectronic instrumentation is used to quantify and monitor wind flow, dust suspension and deposition. This involves a commercial Laser Doppler Anemometer (LDA) and a Particle Dynamics Analysis receiver (PDA), which are small laser based instruments specifically designed for measuring wind speed and sizes of particles situated in a wind flow. Wind flow calibrations will be performed with the LDA system and presented. Pressure and temperature calibrations will follow in order to enable the facility to be used for the testing, development, calibration and comparison of e.g. meteorological sensors under a wide range of environmental conditions as well as multi-disciplinary scientific studies. The wind tunnel is accessible to international collaborators and space agencies for instrument testing, calibration and qualification. It has been financed by the European Space Agency (ESA) as well as the Aarhus University Science Faculty and the Villum Kann Rasmussen Foundation.

Computer Aided Instruction (CAI) for the Shipboard Nontactical ADP Program (SNAP). Interim report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duncan, L.D.; Hammons, C.E.; Hume, R.

Oak Ridge National Laboratory is developing a prototype computer aided instruction package for the Navy Management Systems Support Office. This report discusses the background of the project and the progress to date including a description of the software design, problems encountered, solutions found, and recommendations. The objective of this project is to provide a prototype that will enhance training and can be used as a shipboard refresher and retraining tool. The prototype system will be installed onboard ships where Navy personnel will have ready access to the training. The subsequent testing and evaluation of the prototype could provide the basismore » for a Navy-wide effort to implement computer aided instruction. The work to date has followed a rigorous structured analysis methodology based on the Yourdon/DeMarco techniques. A set of data flow diagrams and a data dictionary are included in the appendices. The problems encountered revolve around requirements to use existing hardware, software, and programmer capabilities for development, implementation, and maintenance of the instructional software. Solutions have been developed which will allow the software to exist in the given environment and still provide advanced features not available in commercial courses.« less

Compact, cost-effective and field-portable microscope prototype based on MISHELF microscopy

NASA Astrophysics Data System (ADS)

Sanz, Martín; Picazo-Bueno, José Ángel; Granero, Luis; García, Javier; Micó, Vicente

2017-02-01

We report on a reduced cost, portable and compact prototype design of lensless holographic microscope with an illumination/detection scheme based on wavelength multiplexing, working with single hologram acquisition and using a fast convergence algorithm for image processing. All together, MISHELF (initials coming from Multi-Illumination Single-Holographic-Exposure Lensless Fresnel) microscopy allows the recording of three Fresnel domain diffraction patterns in a single camera snap-shot incoming from illuminating the sample with three coherent lights at once. Previous implementations have proposed an illumination/detection procedure based on a tuned (illumination wavelengths centered at the maximum sensitivity of the camera detection channels) configuration but here we report on a detuned (non-centered ones) scheme resulting in prototype miniaturization and cost reduction. Thus, MISHELF microscopy in combination with a novel and fast iterative algorithm allows high-resolution (μm range) phase-retrieved (twin image elimination) quantitative phase imaging of dynamic events (video rate recording speed). The performance of this microscope prototype is validated through experiments using both amplitude (USAF resolution test) and complex (live swine sperm cells and flowing microbeads) samples. The proposed method becomes in an alternative instrument improving some capabilities of existing lensless microscopes.

Compact, cost-effective and field-portable microscope prototype based on MISHELF microscopy

PubMed Central

Sanz, Martín; Picazo-Bueno, José Ángel; Granero, Luis; García, Javier; Micó, Vicente

2017-01-01

We report on a reduced cost, portable and compact prototype design of lensless holographic microscope with an illumination/detection scheme based on wavelength multiplexing, working with single hologram acquisition and using a fast convergence algorithm for image processing. All together, MISHELF (initials coming from Multi-Illumination Single-Holographic-Exposure Lensless Fresnel) microscopy allows the recording of three Fresnel domain diffraction patterns in a single camera snap-shot incoming from illuminating the sample with three coherent lights at once. Previous implementations have proposed an illumination/detection procedure based on a tuned (illumination wavelengths centered at the maximum sensitivity of the camera detection channels) configuration but here we report on a detuned (non-centered ones) scheme resulting in prototype miniaturization and cost reduction. Thus, MISHELF microscopy in combination with a novel and fast iterative algorithm allows high-resolution (μm range) phase-retrieved (twin image elimination) quantitative phase imaging of dynamic events (video rate recording speed). The performance of this microscope prototype is validated through experiments using both amplitude (USAF resolution test) and complex (live swine sperm cells and flowing microbeads) samples. The proposed method becomes in an alternative instrument improving some capabilities of existing lensless microscopes. PMID:28233829

Method and apparatus for affecting a recirculation zone in a cross flow

DOEpatents

Bathina, Mahesh [Andhra Pradesh, IN; Singh, Ramanand [Uttar Pradesh, IN

2012-07-17

Disclosed is a cross flow apparatus including a surface and at least one outlet located at the surface. The cross flow apparatus further includes at least one guide at the surface configured to direct an intersecting flow flowing across the surface and increase a velocity of a cross flow being expelled from the at least one outlet downstream from the at least one outlet.

Recent progress in the development of Terumo implantable left ventricular assist system.

PubMed

Nojiri, C; Kijima, T; Maekawa, J; Horiuchi, K; Kido, T; Sugiyama, T; Mori, T; Sugiura, N; Asada, T; Shimane, H; Ozaki, T; Suzuki, M; Akamatsu, T; Akutsu, T

1999-01-01

The research group of the Terumo Corporation, the NTN Corporation, and Setsunan University (T. Akamatsu) has been developing an implantable left ventricular assist system (ILVAS) featuring a centrifugal blood pump with a magnetically suspended impeller (MSCP). The impeller of the MSCP is suspended by a magnetic bearing, providing contact-free rotation of the impeller inside the pump housing. Thus the MSCP is expected to provide years of long-term durability. Ex vivo chronic sheep experiments using the extracorporeal model (Model I) demonstrated long-term durability, nonthrombogenicity, and a low hemolysis rate (plasma free Hb <6 mg/dl) for more than 2 years. The prototype implantable model (Model II; 196 ml, 400 g) was evaluated ex vivo in 2 sheep and intrathoracically implanted in a small sheep (45 kg). These experiments were terminated at 70, 79, and 17 days, respectively, because of blood leakage through the connector system within the housing of Model II. There was no thrombus formation on the retrieved pump surfaces. A new connector system was introduced to the Model II pump (modified Model II), and the pump was intrathoracically implanted in a sheep. Pump flow rate was maintained at 3-7 L/min at 1700-1800 rpm. The temperature elevation on the surfaces of the motor and the electromagnet inside the pump casing was kept less than 6 degrees C. The temperature of the tissue adjacent to the pump casing became normal 10 days postoperatively. The sheep survived for more than 5 months without any sign of mechanical failure or thromboembolic complication. In vitro real-time endurance tests of motor bearings made of stainless steel and silicone nitride have been conducted for more than 1 year without any sign of bearing wear. The next prototype system (Model III), with an implantable controller and a new MSCP with reduced input power, has been developed with a view toward a totally implantable LVAS.

Flow Charts: Visualization of Vector Fields on Arbitrary Surfaces

PubMed Central

Li, Guo-Shi; Tricoche, Xavier; Weiskopf, Daniel; Hansen, Charles

2009-01-01

We introduce a novel flow visualization method called Flow Charts, which uses a texture atlas approach for the visualization of flows defined over curved surfaces. In this scheme, the surface and its associated flow are segmented into overlapping patches, which are then parameterized and packed in the texture domain. This scheme allows accurate particle advection across multiple charts in the texture domain, providing a flexible framework that supports various flow visualization techniques. The use of surface parameterization enables flow visualization techniques requiring the global view of the surface over long time spans, such as Unsteady Flow LIC (UFLIC), particle-based Unsteady Flow Advection Convolution (UFAC), or dye advection. It also prevents visual artifacts normally associated with view-dependent methods. Represented as textures, Flow Charts can be naturally integrated into hardware accelerated flow visualization techniques for interactive performance. PMID:18599918

Visual Modelling of Data Warehousing Flows with UML Profiles

NASA Astrophysics Data System (ADS)

Pardillo, Jesús; Golfarelli, Matteo; Rizzi, Stefano; Trujillo, Juan

Data warehousing involves complex processes that transform source data through several stages to deliver suitable information ready to be analysed. Though many techniques for visual modelling of data warehouses from the static point of view have been devised, only few attempts have been made to model the data flows involved in a data warehousing process. Besides, each attempt was mainly aimed at a specific application, such as ETL, OLAP, what-if analysis, data mining. Data flows are typically very complex in this domain; for this reason, we argue, designers would greatly benefit from a technique for uniformly modelling data warehousing flows for all applications. In this paper, we propose an integrated visual modelling technique for data cubes and data flows. This technique is based on UML profiling; its feasibility is evaluated by means of a prototype implementation.

Application of Rapid Prototyping to the Investment Casting of Test Hardware (MSFC Center Director's Discretionary Fund Final Report, Project No. 98-08)

NASA Technical Reports Server (NTRS)

Cooper, K. G.; Wells, D.

2000-01-01

Investment casting masters of a selected propulsion hardware component, a fuel pump housing, were rapid prototyped on the several processes in-house, along with the new Z-Corp process acquired through this project. Also, tensile samples were prototyped and cast using the same significant parameters. The models were then shelled in-house using a commercial grade zircon-based slurry and stucco technique. Next, the shelled models were fired and cast by our in-house foundry contractor (IITRI), with NASA-23, a commonly used test hardware metal. The cast models are compared by their surface finish and overall appearance (i.e., the occurrence of pitting, warping, etc.), as well as dimensional accuracy.

The NASA Langley Mars Tumbleweed Rover Prototype

NASA Technical Reports Server (NTRS)

Antol, Jeffrey; Chattin, Richard L.; Copeland, Benjamin M.; Krizann, Shawn A.

2005-01-01

Mars Tumbleweed is a concept for an autonomous rover that would achieve mobility through use of the natural winds on Mars. The wind-blown nature of this vehicle make it an ideal platform for conducting random surveys of the surface, scouting for signs of past or present life as well as examining the potential habitability of sites for future human exploration. NASA Langley Research Center (LaRC) has been studying the dynamics, aerodynamics, and mission concepts of Tumbleweed rovers and has recently developed a prototype Mars Tumbleweed Rover for demonstrating mission concepts and science measurement techniques. This paper will provide an overview of the prototype design, instrumentation to be accommodated, preliminary test results, and plans for future development and testing of the vehicle.

Development of a risk-ranking framework to evaluate potential high-threat microorganisms, toxins, and chemicals in food.

PubMed

Newsome, R; Tran, N; Paoli, G M; Jaykus, L A; Tompkin, B; Miliotis, M; Ruthman, T; Hartnett, E; Busta, F F; Petersen, B; Shank, F; McEntire, J; Hotchkiss, J; Wagner, M; Schaffner, D W

2009-03-01

Through a cooperative agreement with the U.S. Food and Drug Administration, the Institute of Food Technologists developed a risk-ranking framework prototype to enable comparison of microbiological and chemical hazards in foods and to assist policy makers, risk managers, risk analysts, and others in determining the relative public health impact of specific hazard-food combinations. The prototype is a bottom-up system based on assumptions that incorporate expert opinion/insight with a number of exposure and hazard-related risk criteria variables, which are propagated forward with food intake data to produce risk-ranking determinations. The prototype produces a semi-quantitative comparative assessment of food safety hazards and the impacts of hazard control measures. For a specific hazard-food combination the prototype can produce a single metric: a final risk value expressed as annual pseudo-disability adjusted life years (pDALY). The pDALY is a harmonization of the very different dose-response relationships observed for chemicals and microbes. The prototype was developed on 2 platforms, a web-based user interface and an Analytica(R) model (Lumina Decision Systems, Los Gatos, Calif., U.S.A.). Comprising visual basic language, the web-based platform facilitates data input and allows use concurrently from multiple locations. The Analytica model facilitates visualization of the logic flow, interrelationship of input and output variables, and calculations/algorithms comprising the prototype. A variety of sortable risk-ranking reports and summary information can be generated for hazard-food pairs, showing hazard and dose-response assumptions and data, per capita consumption by population group, and annual p-DALY.

Structural design of off-axis aspheric surface reflective zoom optical system

NASA Astrophysics Data System (ADS)

Zhang, Ke; Chang, Jun; Song, Haiping; Niu, Yajun

2018-01-01

Designed an off-axis aspheric reflective zoom optical system, and produced a prototype. The system consists of three aspheric reflective lens, the zoom range is 30mm { 90mm. This system gave up the traditional structure of zoom cam, the lens moved using linear guide rail driven by motor, the positioning precision of which was 0.01mm. And introduced the design of support frames of each lens. The practice tests verified the rationality of the prototype structure design.

An experimental investigation of hybrid kerosene burner configurations for TPV applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schroeder, K.L.; Rose, M.F.; Burkhalter, J.E.

1995-01-05

A key element in thermophotovoltaic power generation is the development of a compact and efficient configuration for the thermal source and emitter. In the present work, a hybrid configuration was investigated which was composed of a liquid fueled diffusion type burner utilizing the emitting or mantle structure as the combustion chamber. The prototype burner operates on kerosene at fuel flow rates up to 1.0 kg/hr. Fuel is atomized using an 78 kHz ultrasonic nozzle with multifuel capabilities. Combustion is stabilized and heat transfer is enhanced via forced recirculation interior to the mantle structures. These structures range in size from 600more » to 1200 cm{sup 3} and are porous in nature. This paper presents an introduction to issues specific to the use of small scale liquid fueled burners for TPV applications, and burner performance data for a series of configurations, in terms of combustor surface temperature distribution, maximum mass loading and efficiency. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.« less

Online Oxide Contamination Measurement and Purification Demonstration

NASA Technical Reports Server (NTRS)

Bradley, D. E.; Godfroy, T. J.; Webster, K. L.; Garber, A. E.; Polzin, K. A.; Childers, D. J.

2011-01-01

Liquid metal sodium-potassium (NaK) has advantageous thermodynamic properties indicating its use as a fission reactor coolant for a surface (lunar, martian) power system. A major area of concern for fission reactor cooling systems is system corrosion due to oxygen contaminants at the high operating temperatures experienced. A small-scale, approximately 4-L capacity, simulated fission reactor cooling system employing NaK as a coolant was fabricated and tested with the goal of demonstrating a noninvasive oxygen detection and purification system. In order to generate prototypical conditions in the simulated cooling system, several system components were designed, fabricated, and tested. These major components were a fully-sealed, magnetically-coupled mechanical NaK pump, a graphite element heated reservoir, a plugging indicator system, and a cold trap. All system components were successfully demonstrated at a maximum system flow rate of approximately 150 cc/s at temperatures up to 550 C. Coolant purification was accomplished using a cold trap before and after plugging operations which showed a relative reduction in oxygen content.

Potential of silver nanoparticle-coated polyurethane foam as an antibacterial water filter.

PubMed

Jain, Prashant; Pradeep, T

2005-04-05

Silver nanoparticles can be coated on common polyurethane (PU) foams by overnight exposure of the foams to nanoparticle solutions. Repeated washing and air-drying yields uniformly coated PU foam, which can be used as a drinking water filter where bacterial contamination of the surface water is a health risk. Nanoparticles are stable on the foam and are not washed away by water. Morphology of the foam was retained after coating. The nanoparticle binding is due to its interaction with the nitrogen atom of the PU. Online tests were conducted with a prototypical water filter. At a flow rate of 0.5 L/min, in which contact time was of the order of a second, the output count of Escherichia coli was nil when the input water had a bacterial load of 10(5) colony-forming units (CFU) per mL. Combined with the low cost and effectiveness in its applications, the technology may have large implications to developing countries. Copyright (c) 2005 Wiley Periodicals, Inc.

An On-Site Thermoelectric Cooling Device for Cryotherapy and Control of Skin Blood Flow

PubMed Central

Mejia, Natalia; Dedow, Karl; Nguy, Lindsey; Sullivan, Patrick; Khoshnevis, Sepideh; Diller, Kenneth R.

2015-01-01

Cryotherapy involves the surface application of low temperatures to enhance the healing of soft tissue injuries. Typical devices embody a remote source of chilled water that is pumped through a circulation bladder placed on the treatment site. In contrast, the present device uses thermoelectric refrigeration modules to bring the cooling source directly to the tissue to be treated, thereby achieving significant improvements in control of therapeutic temperature while having a reduced size and weight. A prototype system was applied to test an oscillating cooling and heating protocol for efficacy in regulating skin blood perfusion in the treatment area. Data on 12 human subjects indicate that thermoelectric coolers (TECs) delivered significant and sustainable changes in perfusion for both heating (increase by (±SE) 173.0 ± 66.0%, P < 0.005) and cooling (decrease by (±SE) 57.7 ± 4.2%, P < 0.0005), thus supporting the feasibility of a TEC-based device for cryotherapy with local temperature regulation. PMID:26421089

Dynamic "Scanning-Mode" Meniscus Confined Electrodepositing and Micropatterning of Individually Addressable Ultraconductive Copper Line Arrays.

PubMed

Lei, Yu; Zhang, Xianyun; Xu, Dingding; Yu, Minfeng; Yi, Zhiran; Li, Zhixiang; Sun, Aihua; Xu, Gaojie; Cui, Ping; Guo, Jianjun

2018-05-03

Micro- and nanopatterning of cost-effective addressable metallic nanostructures has been a long endeavor in terms of both scientific understanding and industrial needs. Herein, a simple and efficient dynamic meniscus-confined electrodeposition (MCED) technique for precisely positioned copper line micropatterns with superior electrical conductivity (greater than 1.57 × 10 4 S/cm) on glass, silicon, and gold substrates is reported. An unexpected higher printing speed in the evaporative regime is realized for precisely positioned copper lines patterns with uniform width and height under horizontal scanning-mode. The final line height and width depend on the typical behavior of traditional flow coating process, while the surface morphologies and roughness are mainly governed by evaporation-driven electrocrystallization dynamics near the receding moving contact line. Integrated 3D structures and a rapid prototyping of 3D hot-wire anemometer are further demonstrated, which is very important for the freedom integration applications in advanced conceptual devices, such as miniaturized electronics and biomedical sensors and actuators.

Remote semi-continuous flow rate logging seepage meter

NASA Technical Reports Server (NTRS)

Reay, William G.; Walthall, Harry G.

1991-01-01

The movement of groundwater and its associated solutes from upland regions was implicated in the degradation of receiving surface water bodies. Current efforts to directly measure this influx of water incorporate manually operated seepage meters which are hindered by severe limitations. A prototype seepage meter was developed by NASA Langley Research Center and Virginia Polytechnic Institute and State University that will allow for the semi-continuous collection and data logging of seepage flux across the sediment water interface. The meter is designed to operate at depths to 40 meters, and alleviate or minimize all disadvantages associated with traditional methods while remaining cost effective. The unit was designed to operate independently for time periods on the order of weeks with adjustable sample sequences depending upon hydrologic conditions. When used in conjunction with commercially available pressure transducers, this seepage meter allows for correlations to be made between groundwater discharge and tidal/sea state conditions in coastal areas. Field data from the Chesapeake Bay and Florida Bay systems are presented.

EXPERIMENTS - APOLLO 17

NASA Image and Video Library

1972-11-17

S72-53472 (November 1972) --- An artist's concept illustrating how radar beams of the Apollo 17 lunar sounder experiment will probe three-quarters of a mile below the moon's surface from the orbiting spacecraft. The Lunar Sounder will be mounted in the SIM bay of the Apollo 17 Service Module. Electronic data recorded on film will be retrieved by the crew during trans-Earth EVA. Geologic information on the lunar interior obtained by the sounder will permit scientific investigation of underground rock layers, lava flow patterns, rille (canyon) structures, mascon properties, and any areas containing water. A prototype lunar sounder has been flight tested in aircraft over selected Earth sites to confirm the equipment design and develop scientific analysis techniques. The Lunar Sounder Experiment (S-209) was developed by North American Rockwell's (NR) Space Division for NASA's Manned Spacecraft Center to provide data for a scientific investigation team with representatives from the Jet Propulsion Laboratory, University of Utah, University of Michigan, U.S. Geological Survey, and NASA Ames Research Center.

An On-Site Thermoelectric Cooling Device for Cryotherapy and Control of Skin Blood Flow.

PubMed

Mejia, Natalia; Dedow, Karl; Nguy, Lindsey; Sullivan, Patrick; Khoshnevis, Sepideh; Diller, Kenneth R

2015-12-01

Cryotherapy involves the surface application of low temperatures to enhance the healing of soft tissue injuries. Typical devices embody a remote source of chilled water that is pumped through a circulation bladder placed on the treatment site. In contrast, the present device uses thermoelectric refrigeration modules to bring the cooling source directly to the tissue to be treated, thereby achieving significant improvements in control of therapeutic temperature while having a reduced size and weight. A prototype system was applied to test an oscillating cooling and heating protocol for efficacy in regulating skin blood perfusion in the treatment area. Data on 12 human subjects indicate that thermoelectric coolers (TECs) delivered significant and sustainable changes in perfusion for both heating (increase by (±SE) 173.0 ± 66.0%, P < 0.005) and cooling (decrease by (±SE) 57.7 ± 4.2%, P < 0.0005), thus supporting the feasibility of a TEC-based device for cryotherapy with local temperature regulation.

Coating flow of non-Newtonian anti-HIV microbicide vehicles

NASA Astrophysics Data System (ADS)

Park, Su Chan; Szeri, Andrew; Verguet, Stéphane; Katz, David; Weiss, Aaron

2008-11-01

Elastohydrodynamic lubrication over soft substrates is of importance for the drug delivery functions of vehicles for anti-HIV topical microbicides. These are intended to inhibit transmission into vulnerable mucosa, e.g. in the vagina. First generation prototype microbicides have gel vehicles, which spread after insertion and coat luminal surfaces. Effectiveness derives from potency of the active ingredients and completeness and durability of coating. Delivery vehicle rheology, luminal biomechanical properties and the force due to gravity influence the coating mechanics. We develop a framework for understanding the relative importance of boundary squeezing and body forces on the extent and speed of the coating that results. In the case of a shear-thinning fluid, the Carreau number also plays a role. Numerical solutions are developed for a range of conditions and materials. Results are interpreted with respect to tradeoffs between wall elasticity, longitudinal forces, bolus viscosity and bolus volume. These provide initial insights of practical value for formulators of non-Newtonian gel delivery vehicles for anti-HIV microbicidal formulations.

New developments in surface technology and prototyping

NASA Astrophysics Data System (ADS)

Himmer, Thomas; Beyer, Eckhard

2003-03-01

Novel lightweight applications in the automotive and aircraft industries require advanced materials and techniques for surface protection as well as direct and rapid manufacturing of the related components and tools. The manufacturing processes presented in this paper are based on multiple additive and subtractive technologies such as laser cutting, laser welding, direct laser metal deposition, laser/plasma hybrid spraying technique or CNC milling. The process chain is similar to layer-based Rapid Prototyping Techniques. In the first step, the 3D CAD geometry is sliced into layers by a specially developed software. These slices are cut by high speed laser cutting and then joined together. In this way laminated tools or parts are built. To improve surface quality and to increase wear resistance a CNC machining center is used. The system consists of a CNC milling machine, in which a 3 kW Nd:YAG laser, a coaxial powder nozzle and a digitizing system are integrated. Using a new laser/plasma hybrid spraying technique, coatings can be deposited onto parts for surface protection. The layers show a low porosity and high adhesion strength, the thickness is up to 0.3 mm, and the lower effort for preliminary surface preparation reduces time and costs of the whole process.

Role of rough surface topography on gas slip flow in microchannels.

PubMed

Zhang, Chengbin; Chen, Yongping; Deng, Zilong; Shi, Mingheng

2012-07-01

We conduct a lattice Boltzmann simulation of gas slip flow in microchannels incorporating rough surface effects as characterized by fractal geometry with a focus on gas-solid interaction. The gas slip flow in rough microchannels, which is characterized by Poiseuille number and mass flow rate, is evaluated and compared with smooth microchannels. The effects of roughness height, surface fractal dimension, and Knudsen number on slip behavior of gas flow in microchannels are all investigated and discussed. The results indicate that the presence of surface roughness reduces boundary slip for gas flow in microchannels with respect to a smooth surface. The gas flows at the valleys of rough walls are no-slip while velocity slips are observed over the top of rough walls. We find that the gas flow behavior in rough microchannels is insensitive to the surface topography irregularity (unlike the liquid flow in rough microchannels) but is influenced by the statistical height of rough surface and rarefaction effects. In particular, decrease in roughness height or increase in Knudsen number can lead to large wall slip for gas flow in microchannels.

Studies on scaling of flow noise received at the stagnation point of an axisymmetric body

NASA Astrophysics Data System (ADS)

Arakeri, V. H.; Satyanarayana, S. G.; Mani, K.; Sharma, S. D.

1991-05-01

A description of the studies related to the problem of scaling of flow noise received at the stagnation point of axisymmetric bodies is provided. The source of flow noise under consideration is the transitional/turbulent regions of the boundary layer flow on the axisymmetric body. Lauchle has recently shown that the noise measured in the laminar region (including the stagnation point) corresponds closely to the noise measured in the transition region, provided that the acoustic losses due to diffraction are accounted for. The present study includes experimental measurement of flow noise at the stagnation point of three different shaped axisymmetric headforms. One of the body shapes chosen is that used by Lauchle in similar studies. This was done to establish the effect of body size on flow noise. The results of the experimental investigations clearly show that the flow noise received at the stagnation point is a strong function of free stream velocity, a moderately strong function of body scale but a weak function of boundary layer thickness. In addition, there is evidence that when body scale change is involved, flow noise amplitude scales but no frequency shift is involved. A scaling procedure is proposed based on the present observations along with those of Lauchle. At a given frequency, the amplitude of noise level obtained under model testing conditions is first scaled to account for differences in the velocity and size corresponding to the prototype conditions; then a correction to this is applied to account for losses due to diffraction, which are estimated on the basis of the geometric theory of diffraction (GTD) with the source being located at the predicted position of turbulent transition. Use of the proposed scaling law to extrapolate presently obtained noise levels to two other conditions involving larger-scale bodies show good agreement with actually measured levels, in particular at higher frequencies. Since model scale results have been used successfully to predict levels on larger-sized bodies tested in a totally different environment, the present data along with the proposed scaling procedure can be used to predict the expected flow noise levels at prototype scales during preliminary design studies.

Laser-absorption sensing of gas composition of products from coal gasification

NASA Astrophysics Data System (ADS)

Jeffries, Jay B.; Sur, Ritobrata; Sun, Kai; Hanson, Ronald K.

2014-06-01

A prototype in-situ laser-absorption sensor for the real-time composition measurement (CO, CH4, H2O and CO2) of synthesis gas products of coal gasification (called here syngas) was designed, tested in the laboratory, and demonstrated during field-measurement campaigns in a pilot-scale entrained flow gasifier at the University of Utah and in an engineering-scale, fluidized-bed transport gasifier at the National Carbon Capture Center (NCCC). The prototype design and operation were improved by the lessons learned from each field test. Laser-absorption measurements are problematic in syngas flows because efficient gasifiers operate at elevated pressures (10-50 atm) where absorption transitions are collision broadened and absorption transitions that are isolated at 1 atm become blended into complex features, and because syngas product streams can contain significant particulate, producing significant non-absorption scattering losses of the transmission of laser light. Thus, the prototype sensor used a new wavelength-scanned, wavelength-modulation spectroscopy strategy with 2f-detection and 1f-normalization (WMS-2f/1f) that can provide sensitive absorption measurements of species with spectra blended by collision broadening even in the presence of large non-absorption laser transmission losses (e.g., particulate scattering, beam steering, etc.). The design of the sensor for detection of CO, CH4, H2O and CO2 was optimized for the specific application of syngas monitoring at the output of large-scale gasifiers. Sensor strategies, results and lessons learned from these field measurement campaigns are discussed.

Resistive Plate Chambers for imaging calorimetry — The DHCAL

NASA Astrophysics Data System (ADS)

Repond, J.

2014-09-01

The DHCAL — the Digital Hadron Calorimeter — is a prototype calorimeter based on Resistive Plate Chambers (RPCs). The design emphasizes the imaging capabilities of the detector in an effort to optimize the calorimeter for the application of Particle Flow Algorithms (PFAs) to the reconstruction of hadronic jet energies in a colliding beam environment. The readout of the chambers is segmented into 1 × 1 cm2 pads, each read out with a 1-bit (single threshold) resolution. The prototype with approximately 500,000 readout channels underwent extensive testing in both the Fermilab and CERN test beams. This talk presents preliminary findings from the analysis of data collected at the test beams.

Kerosene-Fuel Engine Testing Under Way

NASA Image and Video Library

2003-11-17

NASA Stennis Space Center engineers conducted a successful cold-flow test of an RS-84 engine component Sept. 24. The RS-84 is a reusable engine fueled by rocket propellant - a special blend of kerosene - designed to power future flight vehicles. Liquid oxygen was blown through the RS-84 subscale preburner to characterize the test facility's performance and the hardware's resistance. Engineers are now moving into the next phase, hot-fire testing, which is expected to continue into February 2004. The RS-84 engine prototype, developed by the Rocketdyne Propulsion and Power division of The Boeing Co. of Canoga Park, Calif., is one of two competing Rocket Engine Prototype technologies - a key element of NASA's Next Generation Launch Technology program.

Cost analysis of oxygen recovery systems

NASA Technical Reports Server (NTRS)

Yakut, M. M.

1973-01-01

Report is made of the cost analysis of four leading oxygen recovery subsystems which include two carbon dioxide reduction subsystems and two water electrolysis subsystems, namely, the solid polymer electrolyte and the circulating KOH electrolyte. The four oxygen recovery systems were quantitatively evaluated. System characteristics, including process flows, performance, and physical characteristics were also analyzed. Additionally, the status of development of each of the systems considered and the required advance technology efforts required to bring conceptual and/or pre-prototype hardware to an operational prototype status were defined. Intimate knowledge of the operations, development status, and capabilities of the systems to meet space mission requirements were found to be essential in establishing the cost estimating relationships for advanced life support systems.

Kerosene-Fuel Engine Testing Under Way

NASA Technical Reports Server (NTRS)

2003-01-01

NASA Stennis Space Center engineers conducted a successful cold-flow test of an RS-84 engine component Sept. 24. The RS-84 is a reusable engine fueled by rocket propellant - a special blend of kerosene - designed to power future flight vehicles. Liquid oxygen was blown through the RS-84 subscale preburner to characterize the test facility's performance and the hardware's resistance. Engineers are now moving into the next phase, hot-fire testing, which is expected to continue into February 2004. The RS-84 engine prototype, developed by the Rocketdyne Propulsion and Power division of The Boeing Co. of Canoga Park, Calif., is one of two competing Rocket Engine Prototype technologies - a key element of NASA's Next Generation Launch Technology program.

D.R.O.P. The Durable Reconnaissance and Observation Platform

NASA Technical Reports Server (NTRS)

McKenzie, Clifford; Parness, Aaron

2012-01-01

The Durable Reconnaissance and Observation Platform (DROP) is a prototype robotic platform with the ability to climb concrete surfaces up to 85deg at a rate of 25cm/s, make rapid horizontal to vertical transitions, carry an audio/visual reconnaissance payload, and survive impacts from 3 meters. DROP is manufactured using a combination of selective laser sintering (SLS) and shape deposition manufacturing (SDM) techniques. The platform uses a two-wheel, two-motor design that delivers high mobility with low complexity. DROP extends microspine climbing technology from linear to rotary applications, providing improved transition ability, increased speeds, and simpler body mechanics while maintaining microspines ability to opportunistically grip rough surfaces. Various aspects of prototype design and performance are discussed, including the climbing mechanism, body design, and impact survival.

Improved Diffuse Fluorescence Flow Cytometer Prototype for High Sensitivity Detection of Rare Circulating Cells In Vivo

NASA Astrophysics Data System (ADS)

Pestana, Noah Benjamin

Accurate quantification of circulating cell populations is important in many areas of pre-clinical and clinical biomedical research, for example, in the study of cancer metastasis or the immune response following tissue and organ transplants. Normally this is done "ex-vivo" by drawing and purifying a small volume of blood and then analyzing it with flow cytometry, hemocytometry or microfludic devices, but the sensitivity of these techniques are poor and the process of handling samples has been shown to affect cell viability and behavior. More recently "in vivo flow cytometry" (IVFC) techniques have been developed where fluorescently-labeled cells flowing in a small blood vessel in the ear or retina are analyzed, but the sensitivity is generally poor due to the small sampling volume. To address this, our group recently developed a method known as "Diffuse Fluorescence Flow Cytometry" (DFFC) that allows detection and counting of rare circulating cells with diffuse photons, offering extremely high single cell counting sensitivity. In this thesis, an improved DFFC prototype was designed and validated. The chief improvements were three-fold, i) improved optical collection efficiency, ii) improved detection electronics, and iii) development of a method to mitigate motion artifacts during in vivo measurements. In combination, these improvements yielded an overall instrument detection sensitivity better than 1 cell/mL in vivo, which is the most sensitive IVFC system reported to date. Second, development and validation of a low-cost microfluidic device reader for analysis of ocular fluids is described. We demonstrate that this device has equivalent or better sensitivity and accuracy compared a fluorescence microscope, but at an order-of-magnitude reduced cost with simplified operation. Future improvements to both instruments are also discussed.

An ultimate, compact, seal-less centrifugal ventricular assist device: Baylor C-Gyro pump.

PubMed

Ohara, Y; Makinouchi, K; Orime, Y; Tasai, K; Naito, K; Mizuguchi, K; Shimono, T; Damm, G; Glueck, J; Takatani, S

1994-01-01

We have developed a compact, seal-less, all-purpose centrifugal pump, the Baylor C-Gyro pump, which is intended as a long-term ventricular assist device (VAD) as well as a cardiopulmonary bypass pump. In attaining this goal, we began with eliminating the shaft seals by adopting a pivot bearing system at the impeller shaft. In addition, a ring magnet encased in the bottom of the impeller was coupled magnetically to a driver magnet placed outside the pump housing (C1 Prototype). This first model yielded satisfactory performance in vitro with a flow rate of 8 L/min against 250 mm Hg at 2,400 rpm, and an index of hemolysis (IH) of 0.0083 g/100 L using bovine blood. In the second model, the C1 Eccentric Inlet Port Model, the inlet bearing support bar in the prototype were eliminated without reducing the prototype's performance. These designs for antithrombogenicity are being tested by the first in vivo experiment, which has lasted for more than 2 weeks.

Design and prototype fabrication of a 30 tesla cryogenic magnet

NASA Technical Reports Server (NTRS)

Prok, G. M.; Swanson, M. C.; Brown, G. V.

1977-01-01

A liquid-neon-cooled magnet has been designed to produce 30 teslas in steady operation. Its feasibility was established by a previously reported parametric study. To ensure the correctness of the heat transfer relationships used, supercritical neon heat transfer tests were made. Other tests made before the final design included tests on the effect of the magnetic field on pump motors; tensile-shear tests on the cryogenic adhesives; and simulated flow studies for the coolant. The magnet will be made of two pairs of coils, cooled by forced convection of supercritical neon. Heat from the supercritical neon will be rejected through heat exchangers which are made of roll-bonded copper panels and are submerged in a pool of saturated liquid neon. A partial mock-up coil was wound to identify the tooling required to wind the magnet. This was followed by winding a prototype pair of coils. The prototype winding established procedures for fabricating the final magnet and revealed slight changes needed in the final design.

Development of a Prototype Water Pump for Future Space Suit Applications

NASA Technical Reports Server (NTRS)

Hartman, David; Hodgson, Edward; Dionne, Steven; Gervais, Edward, III; Trevino, Luis

2009-01-01

NASA's next generation of space suit systems will place new demands on the pump used to circulate cooling water through the life support system and the crew's liquid cooling garment. Long duration missions and frequent EVA require increased durability and reliability; limited resupply mass requirements demand compatibility with recycled water, and changing system design concepts demand increased tolerance for dissolved and free gas and the ability to operate over a broader range of flow rates and discharge pressure conditions. This paper describes the development of a positive displacement prototype pump to meet these needs. A gerotor based design has been adapted to meet pump performance, gas tolerance, and durability requirements while providing a small, lightweight pump assembly. This design has been detailed and implemented using materials selected to address anticipated water quality and mission needs as a prototype unit for testing in NASA laboratories. Design requirements, pump technology selection and design, performance testing and test results will be discussed.

Development of a Prototype Water Pump for Future Space Suit Applications

NASA Technical Reports Server (NTRS)

Hartman, David; Hodgson, Edward; Gervais, Edward, III; Trevino, Luis

2008-01-01

NASA s next generation of space suit systems will place new demands on the pump used to circulate cooling water through the life support system and the crew s liquid cooling garment. Long duration missions and frequent EVA require increased durability and reliability; limited resupply mass requirements demand compatibility with recycled water, and changing system design concepts demand increased tolerance for dissolved and free gas and the ability to operate over a broader range of flow rates and discharge pressure conditions. This paper describes the development of a positive displacement prototype pump to meet these needs. A gerotor based design has been adapted to meet pump performance, gas tolerance, and durability requirements while providing a small, lightweight pump assembly. This design has been detailed and implemented using materials selected to address anticipated water quality and mission needs as a prototype unit for testing in NASA laboratories. Design requirements, pump technology selection and design, performance testing and test results will be discussed.

A biorobotic model of the human larynx.

PubMed

Manti, M; Cianchetti, M; Nacci, A; Ursino, F; Laschi, C

2015-08-01

This work focuses on a physical model of the human larynx that replicates its main components and functions. The prototype reproduces the multilayer vocal folds and the ab/adduction movements. In particular, the vocal folds prototype is made with soft materials whose mechanical properties have been obtained to be similar to the natural tissue in terms of viscoelasticity. A computational model was used to study fluid-structure interaction between vocal folds and the airflow. This tool allowed us to make a comparison between theoretical and experimental results. Measurements were performed with this prototype in an experimental platform comprising a controlled air flow, pressure sensors and a high-speed camera for measuring vocal fold vibrations. Data included oscillation frequency at the onset pressure and glottal width. Results show that the combination between vocal fold geometry, mechanical properties and dimensions exhibits an oscillation frequency close to that of the human vocal fold. Moreover, computational results show a high correlation with the experimental one.

A quiet tunnel investigation of hypersonic boundary-layer stability over a cooled, flared cone

NASA Technical Reports Server (NTRS)

Blanchard, Alan E.; Selby, Gregory V.; Wilkinson, Stephen P.

1996-01-01

A flared-cone model under adiabatic and cooled-wall conditions was placed in a calibrated, low-disturbance Mach 6 flow and the stability of the boundary layer was investigated using a prototype constant-voltage anemometer. The results were compared with linear-stability theory predictions and good agreement was found in the prediction of second-mode frequencies and growth. In addition, the same 'N = 10' criterion used to predict boundary-layer transition in subsonic, transonic, and supersonic flows under low freestream noise conditions was found to be applicable for the hypersonic flow regime as well. Under cooled-wall conditions, a unique set of spectral data was acquired that documents the linear, nonlinear, and breakdown regions associated with the transition of hypersonic flow under low-noise conditions.

A wireless monitoring system for Hydrocephalus shunts.

PubMed

Narayanaswamy, A; Nourani, M; Tamil, L; Bianco, S

2015-08-01

Patients with Hydrocephalus are usually treated by diverting the excess Cerebrospinal Fluid (CSF) to other parts of the body using shunts. More than 40 percentage of shunts implanted fail within the first two years. Obstruction in the shunts is one of the major causes of failure (45 percent) and the detection of obstruction reduces the complexity of the revision surgery. This paper describes a proposed wireless monitoring system for clog detection and flow measurement in shunts. A prototype was built using multiple pressure sensors along the shunt catheters for sensing the location of clog and flow rate. Regular monitoring of flow rates can be used to adjust the valve in the shunt to prevent over drainage or under drainage of CSF. The accuracy of the flow measurement is more than 90 percent.

DEVELOPMENT AND TESTING OF A WHOLE-AIR SAMPLER FOR MEASUREMENT OF PERSONAL EXPOSURE TO VOLATILE ORGANIC COMPOUNDS

EPA Science Inventory

A small and relatively lightweight (3.35 kg) whole-air (canister) sampler that can be worn to monitor personal exposures to volatile organic compounds was developed and evaluated. The prototype personal whole air sampler (PWAS) consists of a 1-L canister, a mass flow controller, ...

The Design of Immersive English Learning Environment Using Augmented Reality

ERIC Educational Resources Information Center

Li, Kuo-Chen; Chen, Cheng-Ting; Cheng, Shein-Yung; Tsai, Chung-Wei

2016-01-01

The study uses augmented reality (AR) technology to integrate virtual objects into the real learning environment for language learning. The English AR classroom is constructed using the system prototyping method and evaluated by semi-structured in-depth interviews. According to the flow theory by Csikszenmihalyi in 1975 along with the immersive…

Data management for Computer-Aided Engineering (CAE)

NASA Technical Reports Server (NTRS)

Bryant, W. A.; Smith, M. R.

1984-01-01

Analysis of data flow through the design and manufacturing processes has established specific information management requirements and identified unique problems. The application of data management technology to the engineering/manufacturing environment addresses these problems. An overview of the IPAD prototype data base management system, representing a partial solution to these problems, is presented here.

Erosion Control of Scour during Construction; Report 2. Literature Survey of Theoretical, Experimental, and Prototype Investigations.

DTIC Science & Technology

1980-08-01

induced currents around the breakwaters. Experiments were conducted by Hotta and Marui (1976) to investigate characteristics of the local scour; and it...on Oscillatory Boundary Layer Flow," Proceedings, Eleventh Conference on Coastal Engineering, London, England, Vol I, pp 467-486. Hotta, S., and Marui

A First Step Towards Network Security Virtualization: From Concept to Prototype

DTIC Science & Technology

2015-10-01

ec2 security groups. http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-network- security.html. [3] Jeffrey R. Ballard, Ian Rae, and Aditya...20] Matthew L. Meola Michael J. Freedman Jennifer Rexford Nate Foster, Rob Harrison and David Walker. Frenetic: A High-Level Langauge for OpenFlow

Morphodynamics of semi-alluvial streams in northern Fennoscandia: a flume experiment to determine bedform self-organization

NASA Astrophysics Data System (ADS)

Polvi, Lina

2017-04-01

Streams in northern Fennoscandia have two characteristics that complicate a process-based understanding of sediment transport affecting channel form: (1) they are typically semi-alluvial, in that they contain coarse glacial legacy sediment, and (2) numerous mainstem lakes buffer sediment and water fluxes. Systematic studies of these streams are complicated because natural reference sites are lacking due to over a century of widespread channel simplification to aid timber-floating. This research is part of a larger project to determine controls on channel geometry and sediment transport at: (1) the catchment scale, examining downstream hydraulic geometry, (2) the reach scale, examining sediment transport, and (3) the bedform scale, examining the potential for predictable bedform formation. The objective of the current study, targeting the bedform scale, was to use a flume experiment to determine whether sediment self-organizes and creates bedforms in semi-alluvial channels. The prototype channels, tributaries to the unregulated Vindel River in northern Sweden that are being restored after timber-floating, contain coarse sediment (D16: 55 mm, D50:250 mm, D84:620 mm) with moderately steep slopes (2-5%) and typically experience snowmelt-flooding and flooding due to ice jams. Using a scaling factor of 8 for Froude number similitude, an 8-m long, 1.1 m wide fixed-bed flume was set up at the Colorado State University Engineering Research Center with a scaled-down sediment distribution analogous to the prototype channels. For two flume setups, with bed slopes of 2% and 5%, four runs were conducted with flows analogous to QBF, Q2, Q10 and Q50 flows in the prototype channels until equilibrium conditions were reached. Digital elevation models (DEMs) of bed topography were constructed before and after each run using structure-from-motion photogrammetry. To examine self-organization of sediment, DEMs of difference between pre-flow conditions and after each flow were created; scour and deposition in relation to large immobile clasts were examined. Preliminary results show that at high flows at the lower slope (2%), fine sediment was deposited above immobile clasts and scour was common below. High flows at the higher slope (5%) caused scour above and occasionally directly below immobile clasts, with fine sediment deposited nearby scour zones above immobile clasts. These results indicate that these channels experience a shielding effect by large immobile clasts, inhibiting bedload transport and creating pockets of fine sediment upstream of large boulders. Additionally, pools downstream of immobile boulders may experience velocity reversals, causing scour instead of deposition in low-velocity zones. In addition, the combined aggradation and degradation between the Q50 and Q10 flows was less than between the Q10 and Q2 flows. This is most likely because the snowmelt-dominated flow regime of northern Sweden with buffering capacity of lakes precludes extremely high flows, causing a small difference in intermediate- and high-recurrence interval flow magnitudes. Therefore, flows with an intermediate recurrence interval likely do the most geomorphic work, but major sediment self-organization as seen in alluvial mountain streams is unlikely barring an extreme event. In conclusion, classical slope-dependent bedform relationships found in alluvial gravel-bed streams may not be applicable in semi-alluvial channels in northern Fennoscandia.

Testing of SMA-enabled Active Chevron Prototypes under Representative Flow Conditions

NASA Technical Reports Server (NTRS)

Turner, Travis L.; Cabell,Randolph H.; Cano, Roberto J.; Silcox, Richard J.

2008-01-01

Control of jet noise continues to be an important research topic. Exhaust-nozzle chevrons have been shown to reduce jet noise, but parametric effects are not well understood. Additionally, thrust loss due to chevrons at cruise suggests significant benefit from active chevrons. The focus of this study is development of an active chevron concept for the primary purpose of parametric studies for jet noise reduction in the laboratory and secondarily for technology development to leverage for full scale systems. The active chevron concept employed in this work consists of a laminated composite structure with embedded shape memory alloy (SMA) actuators, termed a SMA hybrid composite (SMAHC). SMA actuators are embedded on one side of the neutral axis of the structure such that thermal excitation, via joule heating, generates a moment and deflects the structure. The performance of two active chevron concepts is demonstrated in the presence of representative flow conditions. One of the concepts is shown to possess significant advantages for the proposed application and is selected for further development. Fabrication and design changes are described and shown to produce a chevron prototype that meets the performance objectives.

Design of a pulsatile DC electromagnetic blood pump for ECMO.

PubMed

Liu, Jingjing; Ge, Bin; Lu, Tong

2017-08-09

Extracorporeal membrane oxygenation (ECMO) has developed rapidly and becomes a significant treatment for emergency. Current blood pumps for ECMO have different disadvantages. To design a pulsatile DC electromagnetic blood pump for ECMO. The design is presented with a driving principle which the rectilinear reciprocation of a magnet inside energized solenoids is implemented, and with a structure of solenoids with compensation coils. Furthermore, a prototype was constructed and the performance indexes of it were measured with the experimental evaluations, where the acceleration experiment was performed without any loads, and the flows were measured in the ranges of preload and afterload are 5 to 30 mmHg and 50 to 80 mmHg respectively when the frequency of the motion is 80 beats per minute. The electromagnetic force is greater than 1.4 N when the DC reaches 2.7 A and the flow of the prototype is greater than 3.0 L/min except the differences between the preload and the afterload are greater than or equal to 70 mmHg. The design of the blood pump for ECMO meets the theoretical and clinical requirements.

Optimization of a jet-propelled particle injection system for the uniform transdermal delivery of drug/vaccine.

PubMed

Liu, Yi; Kendall, Mark A F

2007-08-01

A jet-propelled particle injection system, the biolistics, has been developed and employed to accelerate micro-particles for transdermal drug delivery. We have examined a prototype biolistic device employing a converging-diverging supersonic nozzle (CDSN), and found that the micro-particles were delivered with a wide velocity range (200-800 m/s) and spatial distribution. To provide a controllable system for transdermal drug delivery, we present a contoured shock-tube (CST) concept and its embodiment device. The CST configuration utilizes a quasi-steady, quasi-one dimensional and shock-free supersonic flow to deliver the micro-particles with an almost uniform velocity (the mean velocity and the standard deviation, 699 +/- 4.7 m/s) and spatial distribution. The transient gas and particle dynamics in both prototype devices are interrogated with the validated computational fluid dynamics (CFD) approach. The predicted results for static pressure and Mach number histories, gas flow structures, particle velocity distributions and gas-particle interactions are presented and interpreted. The implications for clinical uses are discussed. (c) 2007 Wiley Periodicals, Inc.

In-vacuum scattered light reduction with black cupric oxide surfaces for sensitive fluorescence detection.

PubMed

Norrgard, E B; Sitaraman, N; Barry, J F; McCarron, D J; Steinecker, M H; DeMille, D

2016-05-01

We demonstrate a simple and easy method for producing low-reflectivity surfaces that are ultra-high vacuum compatible, may be baked to high temperatures, and are easily applied even on complex surface geometries. Black cupric oxide (CuO) surfaces are chemically grown in minutes on any copper surface, allowing for low-cost, rapid prototyping, and production. The reflective properties are measured to be comparable to commercially available products for creating optically black surfaces. We describe a vacuum apparatus which uses multiple blackened copper surfaces for sensitive, low-background detection of molecules using laser-induced fluorescence.

Microgravity

NASA Image and Video Library

2001-01-24

Advanced finite element models are used to study three-dimensional, time-dependent flow and segregation in crystal growth systems. In this image of a prototypical model for melt and crystal growth, pathlines at one instant in time are shown for the flow of heated liquid silicon in a cylindrical container. The container is subjected to g-jitter disturbances along the vertical axis. A transverse magnetic field is applied to control them. Such computations are extremely powerful for understanding melt growth in microgravity where g-jitter drives buoyant flows. The simulation is part of the Theoretical Analysis of 3D, Transient Convection and Segregation in Microgravity Bridgman Crystal Growth investigation by Dr. Jeffrey J. Derby of the University of Mirnesota, Minneapolis.

Microgravity crystal growth

NASA Technical Reports Server (NTRS)

2001-01-01

Advanced finite element models are used to study three-dimensional, time-dependent flow and segregation in crystal growth systems. In this image of a prototypical model for melt and crystal growth, pathlines at one instant in time are shown for the flow of heated liquid silicon in a cylindrical container. The container is subjected to g-jitter disturbances along the vertical axis. A transverse magnetic field is applied to control them. Such computations are extremely powerful for understanding melt growth in microgravity where g-jitter drives buoyant flows. The simulation is part of the Theoretical Analysis of 3D, Transient Convection and Segregation in Microgravity Bridgman Crystal Growth investigation by Dr. Jeffrey J. Derby of the University of Mirnesota, Minneapolis.

Using Selective Drainage Methods to Extract Continuous Surface Flow from 1-Meter Lidar-Derived Digital Elevation Data

USGS Publications Warehouse

Poppenga, Sandra K.; Worstell, Bruce B.; Stoker, Jason M.; Greenlee, Susan K.

2010-01-01

Digital elevation data commonly are used to extract surface flow features. One source for high-resolution elevation data is light detection and ranging (lidar). Lidar can capture a vast amount of topographic detail because of its fine-scale ability to digitally capture the surface of the earth. Because elevation is a key factor in extracting surface flow features, high-resolution lidar-derived digital elevation models (DEMs) provide the detail needed to consistently integrate hydrography with elevation, land cover, structures, and other geospatial features. The U.S. Geological Survey has developed selective drainage methods to extract continuous surface flow from high-resolution lidar-derived digital elevation data. The lidar-derived continuous surface flow network contains valuable information for water resource management involving flood hazard mapping, flood inundation, and coastal erosion. DEMs used in hydrologic applications typically are processed to remove depressions by filling them. High-resolution DEMs derived from lidar can capture much more detail of the land surface than courser elevation data. Therefore, high-resolution DEMs contain more depressions because of obstructions such as roads, railroads, and other elevated structures. The filling of these depressions can significantly affect the DEM-derived surface flow routing and terrain characteristics in an adverse way. In this report, selective draining methods that modify the elevation surface to drain a depression through an obstruction are presented. If such obstructions are not removed from the elevation data, the filling of depressions to create continuous surface flow can cause the flow to spill over an obstruction in the wrong location. Using this modified elevation surface improves the quality of derived surface flow and retains more of the true surface characteristics by correcting large filled depressions. A reliable flow surface is necessary for deriving a consistently connected drainage network, which is important in understanding surface water movement and developing applications for surface water runoff, flood inundation, and erosion. Improved methods are needed to extract continuous surface flow features from high-resolution elevation data based on lidar.

New prototype scintillator detector for the Tibet ASγ experiment

NASA Astrophysics Data System (ADS)

Zhang, Y.; Gou, Q.-B.; Cai, H.; Chen, T.-L.; Danzengluobu; Feng, C.-F.; Feng, Y.-L.; Feng, Z.-Y.; Gao, Q.; Gao, X.-J.; Guo, Y.-Q.; Guo, Y.-Y.; Hou, Y.-Y.; Hu, H.-B.; Jin, C.; Li, H.-J.; Liu, C.; Liu, M.-Y.; Qian, X.-L.; Tian, Z.; Wang, Z.; Xue, L.; Zhang, X.-Y.; Zhang, Xi-Ying

2017-11-01

The hybrid Tibet AS array was successfully constructed in 2014. It has 4500 m2 underground water Cherenkov pools used as the muon detector (MD) and 789 scintillator detectors covering 36900 m2 as the surface array. At 100 TeV, cosmic-ray background events can be rejected by approximately 99.99%, according to the full Monte Carlo (MC) simulation for γ-ray observations. In order to use the muon detector efficiently, we propose to extend the surface array area to 72900 m2 by adding 120 scintillator detectors around the current array to increase the effective detection area. A new prototype scintillator detector is developed via optimizing the detector geometry and its optical surface, by selecting the reflective material and adopting dynode readout. {This detector can meet our physics requirements with a positional non-uniformity of the output charge within 10% (with reference to the center of the scintillator), time resolution FWHM of ~2.2 ns, and dynamic range from 1 to 500 minimum ionization particles}.

Post Processing Methods used to Improve Surface Finish of Products which are Manufactured by Additive Manufacturing Technologies: A Review

NASA Astrophysics Data System (ADS)

Kumbhar, N. N.; Mulay, A. V.

2016-08-01

The Additive Manufacturing (AM) processes open the possibility to go directly from Computer-Aided Design (CAD) to a physical prototype. These prototypes are used as test models before it is finalized as well as sometimes as a final product. Additive Manufacturing has many advantages over the traditional process used to develop a product such as allowing early customer involvement in product development, complex shape generation and also save time as well as money. Additive manufacturing also possess some special challenges that are usually worth overcoming such as Poor Surface quality, Physical Properties and use of specific raw material for manufacturing. To improve the surface quality several attempts had been made by controlling various process parameters of Additive manufacturing and also applying different post processing techniques on components manufactured by Additive manufacturing. The main objective of this work is to document an extensive literature review in the general area of post processing techniques which are used in Additive manufacturing.

Smoothed particle hydrodynamics study of the roughness effect on contact angle and droplet flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shigorina, Elena; Kordilla, Jannes; Tartakovsky, Alexandre M.

We employ a pairwise force Smoothed Particle Hydrodynamics (PF-SPH) model to simulate sessile and transient droplets on rough hydrophobic and hydrophilic surfaces. PF-SPH allows for modeling of free surface flow without discretizing the air phase, which is achieved by imposing the surface tension and dynamic contact angles with pairwise interaction forces. We use the PF-SPH model to study the effect of surface roughness and microscopic contact angle on the effective contact angle and droplet dynamics. In the first part of this work, we investigate static contact angles of sessile droplets on rough surfaces in a shape of a sinusoidal functionmore » and made of rectangular bars placed on top of a flat surface. We find that the effective static contact angles of Cassie and Wenzel droplets on a rough surface are greater than the corresponding microscale static contact angles. As a result, microscale hydrophobic rough surfaces also show effective hydrophobic behavior. On the other hand, microscale hydrophilic surfaces may be macroscopically hydrophilic or hydrophobic, depending on the type of roughness. Next, we study the impact of the roughness orientation (i.e., an anisotropic roughness) and surface inclination on droplet flow velocities. Simulations show that droplet flow velocities are lower if the surface roughness is oriented perpendicular to the flow direction. If the predominant elements of surface roughness are in alignment with the flow direction, the flow velocities increase compared to smooth surfaces, which can be attributed to the decrease in fluid-solid contact area similar to the classical lotus effect. We demonstrate that linear scaling relationships between Bond and capillary number for droplet flow on flat surfaces also hold for flow on rough surfaces.« less

Combined Pressure, Temperature Contrast and Surface-Enhanced Separation of Carbon Dioxide for Post-Combustion Carbon Capture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhen; Wong, Michael; Gupta, Mayank

The Rice University research team developed a hybrid carbon dioxide (CO 2) absorption process combining absorber and stripper columns using a high surface area ceramic foam gas-liquid contactor for enhanced mass transfer and utilizing waste heat for regeneration. This integrated absorber/desorber arrangement will reduce space requirements, an important factor for retrofitting existing coal-fired power plants with CO 2 capture technology. Described in this report, we performed an initial analysis to estimate the technical and economic feasibility of the process. A one-dimensional (1D) CO 2 absorption column was fabricated to measure the hydrodynamic and mass transfer characteristics of the ceramic foam.more » A bench-scale prototype was constructed to implement the complete CO 2 separation process and tested to study various aspects of fluid flow in the process. A model was developed to simulate the two-dimensional (2D) fluid flow and optimize the CO 2 capture process. Test results were used to develop a final technoeconomic analysis and identify the most appropriate absorbent as well as optimum operating conditions to minimize capital and operating costs. Finally, a technoeconomic study was performed to assess the feasibility of integrating the process into a 600 megawatt electric (MWe) coal-fired power plant. With process optimization, $82/MWh of COE can be achieved using our integrated absorber/desorber CO 2 capture technology, which is very close to DOE's target that no more than a 35% increase in COE with CCS. An environmental, health, and safety (EH&S) assessment of the capture process indicated no significant concern in terms of EH&S effects or legislative compliance.« less

CFD-ACE+: a CAD system for simulation and modeling of MEMS

NASA Astrophysics Data System (ADS)

Stout, Phillip J.; Yang, H. Q.; Dionne, Paul; Leonard, Andy; Tan, Zhiqiang; Przekwas, Andrzej J.; Krishnan, Anantha

1999-03-01

Computer aided design (CAD) systems are a key to designing and manufacturing MEMS with higher performance/reliability, reduced costs, shorter prototyping cycles and improved time- to-market. One such system is CFD-ACE+MEMS, a modeling and simulation environment for MEMS which includes grid generation, data visualization, graphical problem setup, and coupled fluidic, thermal, mechanical, electrostatic, and magnetic physical models. The fluid model is a 3D multi- block, structured/unstructured/hybrid, pressure-based, implicit Navier-Stokes code with capabilities for multi- component diffusion, multi-species transport, multi-step gas phase chemical reactions, surface reactions, and multi-media conjugate heat transfer. The thermal model solves the total enthalpy from of the energy equation. The energy equation includes unsteady, convective, conductive, species energy, viscous dissipation, work, and radiation terms. The electrostatic model solves Poisson's equation. Both the finite volume method and the boundary element method (BEM) are available for solving Poisson's equation. The BEM method is useful for unbounded problems. The magnetic model solves for the vector magnetic potential from Maxwell's equations including eddy currents but neglecting displacement currents. The mechanical model is a finite element stress/deformation solver which has been coupled to the flow, heat, electrostatic, and magnetic calculations to study flow, thermal electrostatically, and magnetically included deformations of structures. The mechanical or structural model can accommodate elastic and plastic materials, can handle large non-linear displacements, and can model isotropic and anisotropic materials. The thermal- mechanical coupling involves the solution of the steady state Navier equation with thermoelastic deformation. The electrostatic-mechanical coupling is a calculation of the pressure force due to surface charge on the mechanical structure. Results of CFD-ACE+MEMS modeling of MEMS such as cantilever beams, accelerometers, and comb drives are discussed.

The Design, Prototyping, and Formative Evaluation of an Assistive Robotic Table (ART) for Stroke Patients.

PubMed

Threatt, Anthony L; Merino, Jessica; Brooks, Johnell O; Healy, Stan; Truesdail, Constance; Manganelli, Joseph; Walker, Ian; Green, Keith Evan

2017-04-01

This article presents the results of an exploratory study in which 14 healthcare subject matter experts (H-SMEs) in addition to four research and design subject matter experts (RD-SMEs) at a regional rehabilitation hospital engaged in a series of complementary, participatory activities in order to design an assistive robotic table (ART). As designers, human factor experts, and healthcare professionals continue to work to integrate assistive human-robot technologies in healthcare, it is imperative to understand how the technology affects patient care from clinicians' perspectives. Fourteen clinical H-SMEs rated a subset of conceptual ART design ideas; participated in the iterative design process of ART; and evaluated a final cardboard prototype, the rehabilitation hospital's current over-the-bed table (OBT), an ART built with true materials, and two therapy surface prototypes. Four RD-SMEs conducted a heuristic evaluation on the ART built with true materials. Data were analyzed by frequency and content analysis. The results include a design and prototype for the next generation ART and a pneumatically controlled therapy surface, a broadened list of specifications for the future design and implementation of assistive robotic furniture, and final observations. When compared to the rehabilitation hospital's current OBT, the developed ART in this study was successful. Designing novel features is dependent upon ensuring patient safety. The inclusion of clinicians in the participatory iterative design and evaluation process and the use of personas provided a broadened list of specifications for the successful implementation of assistive robotic furniture.

Performance of a pilot showcase of different wetland systems in an urban setting in Singapore.

PubMed

Quek, B S; He, Q H; Sim, C H

2015-01-01

The Alexandra Wetlands, part of PUB's Active, Beautiful, Clean Waters (ABC Waters) Programme, showcase a surface flow wetland, an aquatic pond and a sub-surface flow wetland on a 200 m deck built over an urban drainage canal. Water from the canal is pumped to a sedimentation basin, before flowing in parallel to the three wetlands. Water quality monitoring was carried out monthly from April 2011 to December 2012. The order of removal efficiency is sub-surface flow (81.3%) >aquatic pond (58.5%) >surface flow (50.7%) for total suspended solids (TSS); sub-surface (44.9%) >surface flow (31.9%) >aquatic pond (22.0%) for total nitrogen (TN); and surface flow (56.7%) >aquatic pond (39.8%) >sub-surface flow (5.4%) for total phosphorus (TP). All three wetlands achieved the Singapore stormwater treatment objectives (STO) for TP removal, but only the sub-surface flow wetland met the STO for TSS, and none met the STO for TN. Challenges in achieving satisfactory performance include inconsistent feed water quality, undesirable behaviour such as fishing, release of pets and feeding of animals in the wetlands, and canal dredging during part of the monitoring period. As a pilot showcase, the Alexandra Wetlands provide useful lessons for implementing multi-objective wetlands in an urban setting.

Calculation of the flow field including boundary layer effects for supersonic mixed compression inlets at angles of attack

NASA Technical Reports Server (NTRS)

Vadyak, J.; Hoffman, J. D.

1982-01-01

The flow field in supersonic mixed compression aircraft inlets at angle of attack is calculated. A zonal modeling technique is employed to obtain the solution which divides the flow field into different computational regions. The computational regions consist of a supersonic core flow, boundary layer flows adjacent to both the forebody/centerbody and cowl contours, and flow in the shock wave boundary layer interaction regions. The zonal modeling analysis is described and some computational results are presented. The governing equations for the supersonic core flow form a hyperbolic system of partial differential equations. The equations for the characteristic surfaces and the compatibility equations applicable along these surfaces are derived. The characteristic surfaces are the stream surfaces, which are surfaces composed of streamlines, and the wave surfaces, which are surfaces tangent to a Mach conoid. The compatibility equations are expressed as directional derivatives along streamlines and bicharacteristics, which are the lines of tangency between a wave surface and a Mach conoid.

Flow Resistivity Instrument

NASA Technical Reports Server (NTRS)

Zuckerwar, A. J. (Inventor)

1983-01-01

A method and apparatus for making in-situ measurements of flow resistivity on the Earth's ground surface is summarized. The novel feature of the invention is two concentric cylinders, inserted into the ground surface with a measured pressure applied to the surface inside the inner cylinder. The outer cylinder vents a plane beneath the surface to the atmosphere through an air space. The flow to the inner cylinder is measured thereby indicating the flow from the surface to the plane beneath the surface.

Realization of a quantum Hamiltonian Boolean logic gate on the Si(001):H surface.

PubMed

Kolmer, Marek; Zuzak, Rafal; Dridi, Ghassen; Godlewski, Szymon; Joachim, Christian; Szymonski, Marek

2015-08-07

The design and construction of the first prototypical QHC (Quantum Hamiltonian Computing) atomic scale Boolean logic gate is reported using scanning tunnelling microscope (STM) tip-induced atom manipulation on an Si(001):H surface. The NOR/OR gate truth table was confirmed by dI/dU STS (Scanning Tunnelling Spectroscopy) tracking how the surface states of the QHC quantum circuit on the Si(001):H surface are shifted according to the input logical status.

Prototype to measure bracket debonding force in vivo.

PubMed

Tonus, Jéssika Lagni; Manfroi, Fernanda Borguetti; Borges, Gilberto Antonio; Grigolo, Eduardo Correa; Helegda, Sérgio; Spohr, Ana Maria

2017-02-01

Material biodegradation that occurs in the mouth may interfere in the bonding strength between the bracket and the enamel, causing lower bond strength values in vivo, in comparison with in vitro studies. To develop a prototype to measure bracket debonding force in vivo and to evaluate, in vitro, the bond strength obtained with the prototype. A original plier (3M Unitek) was modified by adding one strain gauge directly connected to its claw. An electronic circuit performed the reading of the strain gauge, and the software installed in a computer recorded the values of the bracket debonding force, in kgf. Orthodontic brackets were bonded to the facial surface of 30 bovine incisors with adhesive materials. In Group 1 (n = 15), debonding was carried out with the prototype, while tensile bond strength testing was performed in Group 2 (n = 15). A universal testing machine was used for the second group. The adhesive remnant index (ARI) was recorded. According to Student's t test (α = 0.05), Group 1 (2.96 MPa) and Group 2 (3.08 MPa) were not significantly different. ARI score of 3 was predominant in the two groups. The prototype proved to be reliable for obtaining in vivo bond strength values for orthodontic brackets.

A One-Piece Lunar Regolith Bag Garage Prototype

NASA Technical Reports Server (NTRS)

Smithers, G. A.; Nehls, M. K.; Hovater, M. A.; Evans, S. W.; Miller, J. S.; Broughton, R. M., Jr.; Beale, D.; Kilinc-Balci, F.

2007-01-01

Shelter structures on the moon, even in early phases of exploration, should incorporate lunar materials as much as possible. This Technical Memorandum details the design and construction of a prototype for a one-piece regolith bag unpressurized garage concept and a materials testing program to investigate six candidate fabrics to learn how they might perform in the lunar environment. The conceptualization was that a lightweight fabric form be launched from Earth and landed on the lunar surface to be robotically filled with raw lunar regolith. Regolith bag fabric candidates included: Vectran(TM), Nextel(TM), Gore PTFE Fabric(TM), Zylon(TM), Twaron(TM), and Nomex(TM). Tensile (including post radiation exposure), fold, abrasion, and hypervelocity impact testing were performed under ambient conditions, and also performed under cold and elevated temperatures. In some cases, Johnson Space Center lunar simulant (JSC-1) was used in conjunction with testing. A series of preliminary structures was constructed during final prototype design based on the principles of the classic masonry arch. The prototype was constructed of Kevlar(TM) and filled with vermiculite. The structure is free-standing, but has not yet been load tested. Future plans would be to construct higher fidelity prototypes and to conduct appropriate tests of the structure.

Validation of Reverse-Engineered and Additive-Manufactured Microsurgical Instrument Prototype.

PubMed

Singh, Ramandeep; Suri, Ashish; Anand, Sneh; Baby, Britty

2016-12-01

With advancements in imaging techniques, neurosurgical procedures are becoming highly precise and minimally invasive, thus demanding development of new ergonomically aesthetic instruments. Conventionally, neurosurgical instruments are manufactured using subtractive manufacturing methods. Such a process is complex, time-consuming, and impractical for prototype development and validation of new designs. Therefore, an alternative design process has been used utilizing blue light scanning, computer-aided designing, and additive manufacturing direct metal laser sintering (DMLS) for microsurgical instrument prototype development. Deviations of DMLS-fabricated instrument were studied by superimposing scan data of fabricated instrument with the computer-aided designing model. Content and concurrent validity of the fabricated prototypes was done by a group of 15 neurosurgeons by performing sciatic nerve anastomosis in small laboratory animals. Comparative scoring was obtained for the control and study instrument. T test was applied to the individual parameters and P values for force (P < .0001) and surface roughness (P < .01) were found to be statistically significant. These 2 parameters were further analyzed using objective measures. Results depicts that additive manufacturing by DMLS provides an effective method for prototype development. However, direct application of these additive-manufactured instruments in the operating room requires further validation. © The Author(s) 2016.

Preliminary assessment of the GOES-R ABI hourly land surface albedo and reflectance products prototyped with Himawari AHI data

NASA Astrophysics Data System (ADS)

He, T.; Liang, S.; Zhang, Y.; Yu, Y.

2016-12-01

Land surface albedo and reflectance are critical geophysical variables used in climate and environmental applications. The multispectral Advanced Baseline Imager (ABI) onboard the next generation geostationary satellites (GOES-R series, set to launch in late 2016) offers high temporal and medium spatial resolution observations, which can be used for monitoring diurnal variation of surface albedo and reflectance. In the GOES-R data processing chain there is no atmospheric correction to generate surface reflectance product, which is usually required for surface albedo estimation. We propose an optimization method to simultaneously retrieve surface bidirectional reflectance distribution function (BRDF) parameters and aerosol optical depth with GOES-R ABI data on a daily-basis, which are used for estimating surface albedo and reflectance. Before the launch of the GOES-R satellite, our algorithm was prototyped with data from the Advanced Himawari Imager (AHI) onboard the Japanese Himawari-8 satellite, which has spectral bands and spatial resolutions similar to GOES-R ABI. Cal/val activities were carried out against ground measurements at the OzFlux sites in Australia and satellite data including albedo/BRDF products from MODIS and Landsat. The preliminary accuracy assessment showed promising results for both the surface albedo and reflectance estimates. The GOES-R surface albedo and reflectance products will serve as critical inputs for downstream GOES-R satellite products and also help improve climate modeling and weather forecasting with a high temporal resolution.

Critical Velocities in Open Capillary Flow

NASA Technical Reports Server (NTRS)

Dreyer, Michael; Langbein, Dieter; Rath, Hans J.

1996-01-01

This paper describes the proposed research program on open capillary flow and the preliminary work performed theoretically and in drop tower experiments. The work focuses on the fundamental physical understanding of the flow through capillary bound geometries, where the circumference of the cross section of the flow path contains free surfaces. Examples for such a flow configuration are capillary vanes in surface tension tanks, flow along edges and corners and flow through liquid bridges. The geometries may be classified by their cross section areas, wetted circumferences and the radii of curvature of the free surfaces. In the streaming float zone the flow path is bound by a free surface only. The ribbon vane is a model for vane types used in surface tension tanks, where a structure in proximity to the tank wall forms a capillary gap. A groove is used in heat pipes for the transportation of the condensed working fluid to the heat source and a wedge may occur in a spaceborne experiment where fluid has to be transported by the means of surface tension. The research objectives are the determination of the maximum volume flux, the observation of the free surfaces and the liquid flow inside the flow path as well as the evaluation of the limiting capillary wave speed. The restriction of the maximum volume flux is due to convective forces (flow velocity exceeding the capillary wave speed) and/or viscous forces, i.e. the viscous head loss along the flow path must be compensated by the capillary pressure due to the curved free surface. Exceeding the maximum volume flux leads to the choking of the flow path, thus the free surface collapses and.gas ingestion occurs at the outlet. The means are ground-based experimental work with plateau tanks and in a drop tower, a sounding rocket flight, and theoretical analysis with integral balances as well as full three dimensional CFD solutions for flow with free surfaces.

The effect of water temperature and synoptic winds on the development of surface flows over narrow, elongated water bodies

NASA Technical Reports Server (NTRS)

Segal, M.; Pielke, R. A.

1985-01-01

Simulations of the thermally induced breeze involved with a relatively narrow, elongated water body is presented in conjunction with evaluations of sensible heat fluxes in a stable marine atmospheric surface layer. The effect of the water surface temperature and of the large-scale synoptic winds on the development of surface flows over the water is examined. As implied by the sensible heat flux patterns, the simulation results reveal the following trends: (1) when the synoptic flow is absent or light, the induced surface breeze is not affected noticeably by a reduction of the water surface temperature; and (2) for stronger synoptic flow, the resultant surface flow may be significantly affected by the water surface temperature.

Surface finish measurement studies

NASA Technical Reports Server (NTRS)

Teague, E. C.

1983-01-01

The performance of stylus instruments for measuring the topography of National Transonic Facility (NTF) model surfaces both for monitoring during fabrication and as an absolute measurement of topography was evaluated. It was found that the shop-grade instruments can damage the surface of models and that their use for monitoring fabrication procedures can lead to surface finishes that are substantially out of range in critical areas of the leading edges. The development of a prototype light-scattering instrument which would allow for rapid assessment of the surface finish of a model is also discussed.

Characteristics of Nitrogen Loss through Surface-Subsurface Flow on Red Soil Slopes of Southeast China

NASA Astrophysics Data System (ADS)

Zheng, Haijin; Liu, Zhao; Zuo, Jichao; Wang, Lingyun; Nie, Xiaofei

2017-12-01

Soil nitrogen (N) loss related to surface flow and subsurface flow (including interflow and groundwater flow) from slope lands is a global issue. A lysimetric experiment with three types of land cover (grass cover, GC; litter cover, LC; and bare land, BL) were carried out on a red soil slope land in southeast China. Total Nitrogen (TN) loss through surface flow, interflow and groundwater flow was observed under 28 natural precipitation events from 2015 to 2016. TN concentrations from subsurface flow on BL and LC plots were, on average, 2.7-8.2 and 1.5-4.4 times greater than TN concentrations from surface flow, respectively; the average concentration of TN from subsurface flow on GC was about 36-56% of that recorded from surface flow. Surface flow, interflow and groundwater flow contributed 0-15, 2-9 and 76-96%, respectively, of loss load of TN. Compared with BL, GC and LC intercepted 83-86% of TN loss through surface runoff; GC intercepted 95% of TN loss through subsurface flow while TN loss through subsurface flow on LC is 2.3 times larger than that on BL. In conclusion, subsurface flow especially groundwater flow is the dominant hydrological rout for N loss that is usually underestimated. Grass cover has the high retention of N runoff loss while litter mulch will increase N leaching loss. These findings provide scientific support to control N runoff loss from the red soil slope lands by using suitable vegetation cover and mulching techniques.

Development and modelisation of a hydro-power conversion system based on vortex induced vibration

NASA Astrophysics Data System (ADS)

Lefebure, David; Dellinger, Nicolas; François, Pierre; Mosé, Robert

2016-11-01

The Vortex Induced Vibration (VIV) phenomenon leads to mechanical issues concerning bluff bodies immerged in fluid flows and have therefore been studied by numerous authors. Moreover, an increasing demand for energy implies the development of alternative, complementary and renewable energy solutions. The main idea of EauVIV project consists in the use of VIV rather than its deletion. When rounded objects are immerged in a fluid flow, vortices are formed and shed on their downstream side, creating a pressure imbalance resulting in an oscillatory lift. A convertor modulus consists of an elastically mounted, rigid cylinder on end-springs, undergoing flow- induced motion when exposed to transverse fluid-flow. These vortices induce cyclic lift forces in opposite directions on the circular bar and cause the cylinder to vibrate up and down. An experimental prototype was developed and tested in a free-surface water channel and is already able to recover energy from free-stream velocity between 0.5 and 1 m.s -1. However, the large number of parameters (stiffness, damping coefficient, velocity of fluid flow, etc.) associated with its performances requires optimization and we choose to develop a complete tridimensionnal numerical model solution. A 3D numerical model has been developed in order to represent the real system behavior and improve it through, for example, the addition of parallel cylinders. The numerical model build up was carried out in three phases. The first phase consists in establishing a 2D model to choose the turbulence model and quantify the dependence of the oscillations amplitudes on the mesh size. The second corresponds to a 3D simulation with cylinder at rest in first time and with vertical oscillation in a second time. The third and final phase consists in a comparison between the experimental system dynamic behavior and its numerical model.

Hypersonic separated flows about "tick" configurations with sensitivity to model design

NASA Astrophysics Data System (ADS)

Moss, J. N.; O'Byrne, S.; Gai, S. L.

2014-12-01

This paper presents computational results obtained by applying the direct simulation Monte Carlo (DSMC) method for hypersonic nonequilibrium flow about "tick-shaped" model configurations. These test models produces a complex flow where the nonequilibrium and rarefied aspects of the flow are initially enhanced as the flow passes over an expansion surface, and then the flow encounters a compression surface that can induce flow separation. The resulting flow is such that meaningful numerical simulations must have the capability to account for a significant range of rarefaction effects; hence the application of the DSMC method in the current study as the flow spans several flow regimes, including transitional, slip, and continuum. The current focus is to examine the sensitivity of both the model surface response (heating, friction and pressure) and flowfield structure to assumptions regarding surface boundary conditions and more extensively the impact of model design as influenced by leading edge configuration as well as the geometrical features of the expansion and compression surfaces. Numerical results indicate a strong sensitivity to both the extent of the leading edge sharpness and the magnitude of the leading edge bevel angle. Also, the length of the expansion surface for a fixed compression surface has a significant impact on the extent of separated flow.

Hypersonic Separated Flows About "Tick" Configurations With Sensitivity to Model Design

NASA Technical Reports Server (NTRS)

Moss, J. N.; O'Byrne, S.; Gai, S. L.

2014-01-01

This paper presents computational results obtained by applying the direct simulation Monte Carlo (DSMC) method for hypersonic nonequilibrium flow about "tick-shaped" model configurations. These test models produces a complex flow where the nonequilibrium and rarefied aspects of the flow are initially enhanced as the flow passes over an expansion surface, and then the flow encounters a compression surface that can induce flow separation. The resulting flow is such that meaningful numerical simulations must have the capability to account for a significant range of rarefaction effects; hence the application of the DSMC method in the current study as the flow spans several flow regimes, including transitional, slip, and continuum. The current focus is to examine the sensitivity of both the model surface response (heating, friction and pressure) and flowfield structure to assumptions regarding surface boundary conditions and more extensively the impact of model design as influenced by leading edge configuration as well as the geometrical features of the expansion and compression surfaces. Numerical results indicate a strong sensitivity to both the extent of the leading edge sharpness and the magnitude of the leading edge bevel angle. Also, the length of the expansion surface for a fixed compression surface has a significant impact on the extent of separated flow.

Suppressing unsteady flow in arterio-venous fistulae

NASA Astrophysics Data System (ADS)

Grechy, L.; Iori, F.; Corbett, R. W.; Shurey, S.; Gedroyc, W.; Duncan, N.; Caro, C. G.; Vincent, P. E.

2017-10-01

Arterio-Venous Fistulae (AVF) are regarded as the "gold standard" method of vascular access for patients with end-stage renal disease who require haemodialysis. However, a large proportion of AVF do not mature, and hence fail, as a result of various pathologies such as Intimal Hyperplasia (IH). Unphysiological flow patterns, including high-frequency flow unsteadiness, associated with the unnatural and often complex geometries of AVF are believed to be implicated in the development of IH. In the present study, we employ a Mesh Adaptive Direct Search optimisation framework, computational fluid dynamics simulations, and a new cost function to design a novel non-planar AVF configuration that can suppress high-frequency unsteady flow. A prototype device for holding an AVF in the optimal configuration is then fabricated, and proof-of-concept is demonstrated in a porcine model. Results constitute the first use of numerical optimisation to design a device for suppressing potentially pathological high-frequency flow unsteadiness in AVF.

Parameterization experiments performed via synthetic mass movements prototypes generated by 3D slope stability simulator

NASA Astrophysics Data System (ADS)

Colangelo, Antonio C.

2010-05-01

The central purpose of this work is to perform a reverse procedure in the mass movement conventional parameterization approach. The idea is to generate a number of synthetic mass movements by means of the "slope stability simulator" (Colangelo, 2007), and compeer their morphological and physical properties with "real" conditions of effective mass movements. This device is an integrated part of "relief unity emulator" (rue), that permits generate synthetic mass movements in a synthetic slope environment. The "rue" was build upon fundamental geomorphological concepts. These devices operate with an integrated set of mechanical, geomorphic and hydrological models. The "slope stability simulator" device (sss) permits to perform a detailed slope stability analysis in a theoretical three dimensional space, by means of evaluation the spatial behavior of critical depths, gradients and saturation levels in the "potential rupture surfaces" inferred along a set of slope profiles, that compounds a synthetic slope unity. It's a meta-stable 4-dimensional object generated by means of "rue", that represents a sequence evolution of a generator profile applied here, was adapted the infinite slope model for slope. Any slope profiles were sliced by means of finite element solution like in Bishop method. For the synthetic slope systems generated, we assume that the potential rupture surface occurs at soil-regolith or soil-rock boundary in slope material. Sixteen variables were included in the "rue-sss" device that operates in an integrated manner. For each cell, the factor of safety was calculated considering the value of shear strength (cohesion and friction) of material, soil-regolith boundary depth, soil moisture level content, potential rupture surface gradient, slope surface gradient, top of subsurface flow gradient, apparent soil bulk density and vegetation surcharge. The slope soil was considered as cohesive material. The 16 variables incorporated in the models were analyzed for each cell in synthetic slope systems performed by relief unity emulator. The central methodological strategy is to locate the potential rupture surfaces (prs), main material discontinuities, like soil-regolith or regolith-rock transitions. Inner these "prs", we would to outline the effective potential rupture surfaces (eprs). This surface is a sub-set of the "prs" that presents safety factor less than unity (f<1), the sub-region in the "prs" equal or deeper than critical depths. When the effective potential rupture surface acquires significant extension with respect the thickness of critical depth and retaining walls, the "slope stability simulator" generates a synthetic mass movement. The overlay material will slide until that a new equilibrium be attained at residual shear strength. These devices generate graphic 3D cinematic sequences of experiments in synthetic slope systems and numerical results about physical and morphological data about scars and deposits. Thus, we have a detailed geotechnical, morphological, topographic and morphometric description of these mass movements prototypes, for deal with effective mass movements found in the real environments.

SIMS prototype system 4: Design data brochure

NASA Technical Reports Server (NTRS)

1978-01-01

A pre-package prototype unit having domestic hot water and room solar heating capability that uses air as the collector fluid is described. This system is designed to be used with a small single-family dwelling where a roof mounted collector array is not feasible. The prototype unit is an assemble containing 203 square feet of effective collector surface with 113 cubic feet of rock storage. The design of structure and storage is modular, which permits expansion and reduction of the collector array and storage bed in 68 square feet and 37 cubic feet increments respectively. The system is designed to be transportable. This permitted assemble and certification testing in one area and installation in another area without tear down and reassemble. Design, installation, operation, performance and maintenance of this system are described.

Thermal Performance of Surface Wick Structures.

NASA Astrophysics Data System (ADS)

Chen, Yongkang; Tavan, Noel; Baker, John; Melvin, Lawrence; Weislogel, Mark

2010-03-01

Microscale surface wick structures that exploit capillary driven flow in interior corners have been designed. In this study we examine the interplay between capillary flow and evaporative heat transfer that effectively reduces the surface temperature. The tests are performed by raising the surface temperature to various levels before the flow is introduced to the surfaces. Certainly heat transfer weakens the capillary driven flow. It is observed, however, the surface temperature can be reduced significantly. The effects of geometric parameters and interconnectivity are to be characterized to identify optimal configurations.

Immobilised enzyme microreactor for screening of multi-step bioconversions: characterisation of a de novo transketolase-ω-transaminase pathway to synthesise chiral amino alcohols.

PubMed

Matosevic, S; Lye, G J; Baganz, F

2011-09-20

Complex molecules are synthesised via a number of multi-step reactions in living cells. In this work, we describe the development of a continuous flow immobilized enzyme microreactor platform for use in evaluation of multi-step bioconversion pathways demonstrating a de novo transketolase/ω-transaminase-linked asymmetric amino alcohol synthesis. The prototype dual microreactor is based on the reversible attachment of His₆-tagged enzymes via Ni-NTA linkage to two surface derivatised capillaries connected in series. Kinetic parameters established for the model transketolase (TK)-catalysed conversion of lithium-hydroxypyruvate (Li-HPA) and glycolaldehyde (GA) to L-erythrulose using a continuous flow system with online monitoring of reaction output was in good agreement with kinetic parameters determined for TK in stop-flow mode. By coupling the transketolase catalysed chiral ketone forming reaction with the biocatalytic addition of an amine to the TK product using a transaminase (ω-TAm) it is possible to generate chiral amino alcohols from achiral starting compounds. We demonstrated this in a two-step configuration, where the TK reaction was followed by the ω-TAm-catalysed amination of L-erythrulose to synthesise 2-amino-1,3,4-butanetriol (ABT). Synthesis of the ABT product via the dual reaction and the on-line monitoring of each component provided a full profile of the de novo two-step bioconversion and demonstrated the utility of this microreactor system to provide in vitro multi-step pathway evaluation. Copyright © 2011 Elsevier B.V. All rights reserved.