Cryoprotectants: A review of the actions and applications of cryoprotective solutes that modulate cell recovery from ultra-low temperatures.

PubMed

Elliott, Gloria D; Wang, Shangping; Fuller, Barry J

2017-06-01

Cryopreservation has become a central technology in many areas of clinical medicine, biotechnology, and species conservation within both plant and animal biology. Cryoprotective agents (CPAs) invariably play key roles in allowing cells to be processed for storage at deep cryogenic temperatures and to be recovered with high levels of appropriate functionality. As such, these CPA solutes possess a wide range of metabolic and biophysical effects that are both necessary for their modes of action, and potentially complicating for cell biological function. Early successes with cryopreservation were achieved by empirical methodology for choosing and applying CPAs. In recent decades, it has been possible to assemble objective information about CPA modes of action and to optimize their application to living systems, but there still remain significant gaps in our understanding. This review sets out the current status on the biological and chemical knowledge surrounding CPAs, and the conflicting effects of protection versus toxicity resulting from the use of these solutes, which are often required in molar concentrations, far exceeding levels found in normal metabolism. The biophysical properties of CPAs that allow them to facilitate different approaches to cryogenic storage, including vitrification, are highlighted. The topics are discussed with reference to the historical background of applying CPAs, and the relevance of cryoprotective solutes in natural freeze tolerant organisms. Improved cryopreservation success will be an essential step in many future areas such as regenerative medicine, seed banking, or stem cell technology. To achieve this, we will need to further improve our understanding of cryobiology, where better and safer CPAs will be key requirements. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of a Smart Release Algorithm for Mid-Air Separation of Parachute Test Articles

NASA Technical Reports Server (NTRS)

Moore, James W.

2011-01-01

The Crew Exploration Vehicle Parachute Assembly System (CPAS) project is currently developing an autonomous method to separate a capsule-shaped parachute test vehicle from an air-drop platform for use in the test program to develop and validate the parachute system for the Orion spacecraft. The CPAS project seeks to perform air-drop tests of an Orion-like boilerplate capsule. Delivery of the boilerplate capsule to the test condition has proven to be a critical and complicated task. In the current concept, the boilerplate vehicle is extracted from an aircraft on top of a Type V pallet and then separated from the pallet in mid-air. The attitude of the vehicles at separation is critical to avoiding re-contact and successfully deploying the boilerplate into a heatshield-down orientation. Neither the pallet nor the boilerplate has an active control system. However, the attitude of the mated vehicle as a function of time is somewhat predictable. CPAS engineers have designed an avionics system to monitor the attitude of the mated vehicle as it is extracted from the aircraft and command a release when the desired conditions are met. The algorithm includes contingency capabilities designed to release the test vehicle before undesirable orientations occur. The algorithm was verified with simulation and ground testing. The pre-flight development and testing is discussed and limitations of ground testing are noted. The CPAS project performed a series of three drop tests as a proof-of-concept of the release technique. These tests helped to refine the attitude instrumentation and software algorithm to be used on future tests. The drop tests are described in detail and the evolution of the release system with each test is described.

Design and Testing of CPAS Main Deployment Bag Energy Modulator

NASA Technical Reports Server (NTRS)

Mollmann, Catherine

2017-01-01

During the developmental testing program for CPAS (Capsule Parachute Assembly System), the parachute system for the NASA Orion Crew Module, simulation revealed that high loads may be experienced by the pilot risers during the most devere deployment conditions. As the role of the pilot parachutes is to deploy the main parachutes, these high loads introduced the possibility of main deployment failure. In order to mitigate these high loads, a set of energy modulators was incorporated between the pilot riser and the main deployment bag. An extensive developmental program was implemented to ensure the adequacy of these energy modulators. After initial design comparisons, the energy modulator design was validated through slow-speed joint tests as well as through high-speed bungee tests. This paper documents the design, development, and results of multiple tests completed on the final design.

Load Asymmetry Observed During Orion Main Parachute Inflation

NASA Technical Reports Server (NTRS)

Morris, Aaron L.; Taylor, Thomas; Olson, Leah

2011-01-01

The Crew Exploration Vehicle Parachute Assembly System (CPAS) has flight tested the first two generations of the Orion parachute program. Three of the second generation tests instrumented the dispersion bridles of the Main parachute with a Tension Measuring System. The goal of this load measurement was to better understand load asymmetry during the inflation process of a cluster of Main parachutes. The CPAS Main parachutes exhibit inflations that are much less symmetric than current parachute literature and design guides would indicate. This paper will examine loads data gathered on three cluster tests, quantify the degree of asymmetry observed, and contrast the results with published design guides. Additionally, the measured loads data will be correlated with videos of the parachute inflation to make inferences about the shape of the parachute and the relative load asymmetry. The goal of this inquiry and test program is to open a dialogue regarding asymmetrical parachute inflation load factors.

Application of Statistically Derived CPAS Parachute Parameters

NASA Technical Reports Server (NTRS)

Romero, Leah M.; Ray, Eric S.

2013-01-01

The Capsule Parachute Assembly System (CPAS) Analysis Team is responsible for determining parachute inflation parameters and dispersions that are ultimately used in verifying system requirements. A model memo is internally released semi-annually documenting parachute inflation and other key parameters reconstructed from flight test data. Dispersion probability distributions published in previous versions of the model memo were uniform because insufficient data were available for determination of statistical based distributions. Uniform distributions do not accurately represent the expected distributions since extreme parameter values are just as likely to occur as the nominal value. CPAS has taken incremental steps to move away from uniform distributions. Model Memo version 9 (MMv9) made the first use of non-uniform dispersions, but only for the reefing cutter timing, for which a large number of sample was available. In order to maximize the utility of the available flight test data, clusters of parachutes were reconstructed individually starting with Model Memo version 10. This allowed for statistical assessment for steady-state drag area (CDS) and parachute inflation parameters such as the canopy fill distance (n), profile shape exponent (expopen), over-inflation factor (C(sub k)), and ramp-down time (t(sub k)) distributions. Built-in MATLAB distributions were applied to the histograms, and parameters such as scale (sigma) and location (mu) were output. Engineering judgment was used to determine the "best fit" distribution based on the test data. Results include normal, log normal, and uniform (where available data remains insufficient) fits of nominal and failure (loss of parachute and skipped stage) cases for all CPAS parachutes. This paper discusses the uniform methodology that was previously used, the process and result of the statistical assessment, how the dispersions were incorporated into Monte Carlo analyses, and the application of the distributions in trajectory benchmark testing assessments with parachute inflation parameters, drag area, and reefing cutter timing used by CPAS.

Development and Overview of CPAS Sasquatch Airdrop Landing Location Predictor Software

NASA Technical Reports Server (NTRS)

Bledsoe, Kristin J.; Bernatovich, Michael A.

2015-01-01

The Capsule Parachute Assembly System (CPAS) is the parachute system for NASA's Orion spacecraft. CPAS is currently in the Engineering Development Unit (EDU) phase of testing. The test program consists of numerous drop tests, wherein a test article rigged with parachutes is extracted from an aircraft. During such tests, range safety is paramount, as is the recoverability of the parachutes and test article. It is crucial to establish a release point from the aircraft that will ensure that the article and all items released from it during flight will land in a designated safe area. The Sasquatch footprint tool was developed to determine this safe release point and to predict the probable landing locations (footprints) of the payload and all released objects. In 2012, a new version of Sasquatch, called Sasquatch Polygons, was developed that significantly upgraded the capabilities of the footprint tool. Key improvements were an increase in the accuracy of the predictions, and the addition of an interface with the Debris Tool (DT), an in-flight debris avoidance tool for use on the test observation helicopter. Additional enhancements include improved data presentation for communication with test personnel and a streamlined code structure. This paper discusses the development, validation, and performance of Sasquatch Polygons, as well as its differences from the original Sasquatch footprint tool.

Krikalev with CPAs in Node 1/Unity CBA

NASA Image and Video Library

2005-06-21

ISS011-E-09392 (21 June 2005) --- Cosmonaut Sergei K. Krikalev, Expedition 11 commander representing Russia's Federal Space Agency, moves one of the two Control Panel Assemblies (CPA) from the Unity node’s Common Berthing Assembly (CBA) on the International Space Station (ISS).

Antenna Measurements: Test & Analysis of the Radiated Emissions/Immunity of the NASA/Orion Spacecraft Dart Parachute Simulator & Prototype Capsule - The Crew Exploration Vehicle

NASA Technical Reports Server (NTRS)

Norgard, John D.

2012-01-01

For future NASA Manned Space Exploration of the Moon and Mars, a blunt body capsule, called the Orion Crew Exploration Vehicle (CEV), composed of a Crew Module (CM) and a Service Module (SM), with a parachute decent assembly is planned for reentry back to Earth. A Capsule Parachute Assembly System (CPAS) is being developed for preliminary prototype parachute drop tests at the Yuma Proving Ground (YPG) to simulate high-speed reentry to Earth from beyond Low-Earth-Orbit (LEO) and to provide measurements of position, velocity, acceleration, attitude, temperature, pressure, humidity, and parachute loads. The primary and secondary (backup) avionics systems on CPAS also provide mission critical firing events to deploy, reef, and release the parachutes in three stages (extraction, drogues, mains) using mortars and pressure cartridge assemblies. In addition, a Mid-Air Delivery System (MDS) is used to separate the capsule from the sled that is used to eject the capsule from the back of the drop plane. Also, high-speed and high-definition cameras in a Video Camera System (VCS) are used to film the drop plane extraction and parachute landing events. Intentional and unintentional radiation emitted from and received by antennas and electronic devices on/in the CEV capsule, the MDS sled, and the VCS system are being tested for radiated emissions/immunity (susceptibility) (RE/RS). To verify Electromagnetic Compatibility (EMC) of the Orion capsule, Electromagnetic Interference (EMI) measurements are being made inside a semi-anechoic chamber at NASA/JSC on the components of the CPAS system. Measurements are made at 1m from the components-under-test (CUT). In addition, EMI measurements of the integrated CEV system are being made inside a hanger at YPG. These measurements are made in a complete circle, at 30? angles or less, around the Orion Capsule, the spacecraft system under-test (SUT). Near-field B-Dot probe measurements on the surface of the Orion capsule are being extrapolated outward to the 1m standard distance for comparison to the MIL-STD radiated emissions limit, and far-field hybrid antenna measurements at 3m are being extrapolated inward to the 1m distance for similar comparisons.

Krikalev with CPAs in Node 1/Unity CBA

NASA Image and Video Library

2005-06-21

ISS011-E-09373 (21 June 2005) --- Cosmonaut Sergei K. Krikalev, Expedition 11 commander representing Russia's Federal Space Agency, prepares to uninstall two of the four Control Panel Assemblies (CPA) from the Unity node’s Common Berthing Assembly (CBA) on the International Space Station (ISS).

Photographic Volume Estimation of CPAS Main Parachutes

NASA Technical Reports Server (NTRS)

Ray, Eric S.

2017-01-01

Capsule Parachute Assembly System (CPAS) flight tests regularly stage a helicopter to observe inflation of 116 ft D o ringsail Main parachutes. These side views can be used to generate 3-D models of inflating canopies to estimate enclosed volume. Assuming a surface of revolution is inadequate because reefed canopies in a cluster are elongated due to mutual aerodynamic interference. A method was developed to combine the side views with upward looking HD video to account for non-circular cross sections. Approximating the cross sections as elliptical greatly improves accuracy. But since that correction requires manually tracing projected outlines, the actual irregular shapes can be used to generate high fidelity models. Compensation is also made for apparent tilt angle. Validation was accomplished by comparing perimeter and projected area with known line lengths and/or high quality photogrammetry.

Improved CPAS Photogrammetric Capabilities for Engineering Development Unit (EDU) Testing

NASA Technical Reports Server (NTRS)

Ray, Eric S.; Bretz, David R.

2013-01-01

This paper focuses on two key improvements to the photogrammetric analysis capabilities of the Capsule Parachute Assembly System (CPAS) for the Orion vehicle. The Engineering Development Unit (EDU) system deploys Drogue and Pilot parachutes via mortar, where an important metric is the muzzle velocity. This can be estimated using a high speed camera pointed along the mortar trajectory. The distance to the camera is computed from the apparent size of features of known dimension. This method was validated with a ground test and compares favorably with simulations. The second major photogrammetric product is measuring the geometry of the Main parachute cluster during steady-state descent using onboard cameras. This is challenging as the current test vehicles are suspended by a single-point attachment unlike earlier stable platforms suspended under a confluence fitting. The mathematical modeling of fly-out angles and projected areas has undergone significant revision. As the test program continues, several lessons were learned about optimizing the camera usage, installation, and settings to obtain the highest quality imagery possible.

Reefing Line Tension in CPAS Main Parachute Clusters

NASA Technical Reports Server (NTRS)

Ray, Eric S.

2013-01-01

Reefing lines are an essential feature to manage inflation loads. During each Engineering Development Unit (EDU) test of the Capsule Parachute Assembly System (CPAS), a chase aircraft is staged to be level with the cluster of Main ringsail parachutes during the initial inflation and reefed stages. This allows for capturing high-quality still photographs of the reefed skirt, suspension line, and canopy geometry. The over-inflation angles are synchronized with measured loads data in order to compute the tension force in the reefing line. The traditional reefing tension equation assumes radial symmetry, but cluster effects cause the reefed skirt of each parachute to elongate to a more elliptical shape. This effect was considered in evaluating multiple parachutes to estimate the semi-major and semi-minor axes. Three flight tests are assessed, including one with a skipped first stage, which had peak reefing line tension over three times higher than the nominal parachute disreef sequence.

Parachute Compartment Drop Test Vehicle for Testing the Crew Exploration Vehicle's Parachute Assembly System

NASA Technical Reports Server (NTRS)

Lubey, Daniel P.; Thiele, Sara R.; Gruseck, Madelyn L.; Evans, Carol T.

2010-01-01

Though getting astronauts safely into orbit and beyond has long been one of NASA?s chief goals, their safe return has always been equally as important. The Crew Exploration Vehicle?s (CEV) Parachute Assembly System (CPAS) is designed to safely return astronauts to Earth on the next-generation manned spacecraft Orion. As one means for validating this system?s requirements and testing its functionality, a test article known as the Parachute Compartment Drop Test Vehicle (PC-DTV) will carry a fully-loaded yet truncated CPAS Parachute Compartment (PC) in a series of drop tests. Two aerodynamic profiles for the PC-DTV currently exist, though both share the same interior structure, and both have an Orion-representative weight of 20,800 lbf. Two extraction methods have been developed as well. The first (Cradle Monorail System 2 - CMS2) uses a sliding rail technique to release the PC-DTV midair, and the second (Modified DTV Sled; MDS) features a much less constrained separation method though slightly more complex. The decision as to which aerodynamic profile and extraction method to use is still not finalized. Additional CFD and stress analysis must be undertaken in order to determine the more desirable options, though at present the "boat tail" profile and the CMS2 extraction method seem to be the favored options in their respective categories. Fabrication of the PC-DTV and the selected extraction sled is set to begin in early October 2010 with an anticipated first drop test in mid-March 2011.

Orion Boiler Plate Airdrop Test System

NASA Technical Reports Server (NTRS)

Machin, Ricardo A.; Evans, Carol T.

2013-01-01

On the 29th of February 2012 the Orion Capsule Parachute Assembly System (CPAS) project attempted to perform an airdrop test of a boilerplate test article for the second time. The first attempt (Cluster Development Test 2, July 2008) to deliver a similar boilerplate from a C-17 using the Low Velocity Air Drop (LVAD) technique resulted in the programmer parachute failing to properly inflate, the test article failing to achieve the desired test initiation conditions, and the test article a total loss. This paper will pick up where the CDT-2 failure investigation left off, describing the test technique that was adopted, and outline the modeling that was performed to gain confidence that the second attempt would be successful. The second boiler plate test (Cluster Development Test 3-3) was indeed a complete success and has subsequently been repeated several times, allowing the CPAS project to proceed with the full scale system level development testing required to integrate the hardware to the first Entry Flight Test vehicle as well as go into the Critical Design Review with minimum risk and a mature design.

Measurement of CPAS Main Parachute Rate of Descent

NASA Technical Reports Server (NTRS)

Ray, Eric S.

2011-01-01

The Crew Exploration Vehicle Parachute Assembly System (CPAS) is being designed to land the Orion Crew Module (CM) at a safe rate of descent at splashdown. Flight test performance must be measured to a high degree of accuracy to ensure this requirement is met with the most efficient design possible. Although the design includes three CPAS Main parachutes, the requirement is that the system must not exceed 33 ft/s under two Main parachutes, should one of the Main parachutes fail. Therefore, several tests were conducted with clusters of two Mains. All of the steady-state rate of descent data are normalized to standard sea level conditions and checked against the limit. As the Orion design gains weight, the system is approaching this limit to within measurement precision. Parachute "breathing," cluster interactions, and atmospheric anomalies can cause the rate of descent to vary widely and lead to challenges in characterizing parachute terminal performance. An early test had contradictory rate of descent results from optical trajectory and Differential Global Positioning Systems (DGPS). A thorough analysis of the data sources and error propagation was conducted to determine the uncertainty in the trajectory. It was discovered that the Time Space Position Information (TSPI) from the optical tracking provided accurate position data. However, the velocity from TPSI must be computed via numerical differentiation, which is prone to large error. DGPS obtains position through pseudo-range calculations from multiple satellites and velocity through Doppler shift of the carrier frequency. Because the velocity from DGPS is a direct measurement, it is more accurate than TSPI velocity. To remedy the situation, a commercial off-the-shelf product that combines GPS and an Inertial Measurement Unit (IMU) was purchased to significantly improve rate of descent measurements. This had the added benefit of solving GPS dropouts during aircraft extraction. Statistical probability distributions for CPAS Main parachute rate of descent and drag coefficient were computed and plotted. Using test data, a terminal rate of descent at splashdown can be estimated as a function of canopy loading.

Pack Density Limitations of Hybrid Parachutes

NASA Technical Reports Server (NTRS)

Zwicker, Matthew L.; Sinclair, Robert J.

2013-01-01

The development and testing of the Orion crew capsule parachute system has provided a unique opportunity to study dense parachute packing techniques and limits, in order to establish a new baseline for future programs. The density of parachute packs has a significant influence on vibration loads, retention system stresses, and parachute mortar performance. Material compositions and pack densities of existing designs for space capsule recovery were compared, using the pack density of the Apollo main parachutes as the current baseline. The composition of parachutes has changed since Apollo, incorporating new materials such as Kevlar , Vectran , Teflon and Spectra . These materials have different specific densities than Nylon, so the densities of hybrid parachute packs cannot be directly compared to Nylon parachutes for determination of feasibility or volume allocation. Six parachute packs were evaluated in terms of weighted average solid density in order to achieve a non-dimensional comparison of packing density. Means of mitigating damage due to packing pressure and mortar firing were examined in light of the Capsule Parachute Assembly System (CPAS) and Apollo experience. Parachute design improvements including incorporation of modern materials and manufacturing processes serves to make CPAS the new knowledge base on which future spacecraft parachute systems will be built.

Simulating New Drop Test Vehicles and Test Techniques for the Orion CEV Parachute Assembly System

NASA Technical Reports Server (NTRS)

Morris, Aaron L.; Fraire, Usbaldo, Jr.; Bledsoe, Kristin J.; Ray, Eric; Moore, Jim W.; Olson, Leah M.

2011-01-01

The Crew Exploration Vehicle Parachute Assembly System (CPAS) project is engaged in a multi-year design and test campaign to qualify a parachute recovery system for human use on the Orion Spacecraft. Test and simulation techniques have evolved concurrently to keep up with the demands of a challenging and complex system. The primary simulations used for preflight predictions and post-test data reconstructions are Decelerator System Simulation (DSS), Decelerator System Simulation Application (DSSA), and Drop Test Vehicle Simulation (DTV-SIM). The goal of this paper is to provide a roadmap to future programs on the test technique challenges and obstacles involved in executing a large-scale, multi-year parachute test program. A focus on flight simulation modeling and correlation to test techniques executed to obtain parachute performance parameters are presented.

Extraction-Separation Performance and Dynamic Modeling of Orion Test Vehicles with Adams Simulation: 2nd Edition

NASA Technical Reports Server (NTRS)

Fraire, Usbaldo, Jr.; Anderson, Keith; Varela, Jose G.; Bernatovich, Michael A.

2015-01-01

NASA's Orion Capsule Parachute Assembly System (CPAS) project has advanced into the third generation of its parachute test campaign and requires technically comprehensive modeling capabilities to simulate multi-body dynamics (MBD) of test articles released from a C-17. Safely extracting a 30,000 lbm mated test article from a C-17 and performing stable mid-air separation maneuvers requires an understanding of the interaction between elements in the test configuration and how they are influenced by extraction parachute performance, aircraft dynamics, aerodynamics, separation dynamics, and kinetic energy experienced by the system. During the real-time extraction and deployment sequences, these influences can be highly unsteady and difficult to bound. An avionics logic window based on time, pitch, and pitch rate is used to account for these effects and target a favorable separation state in real time. The Adams simulation has been employed to fine-tune this window, as well as predict and reconstruct the coupled dynamics of the Parachute Test Vehicle (PTV) and Cradle Platform Separation System (CPSS) from aircraft extraction through the mid-air separation event. The test-technique for the extraction of CPAS test articles has evolved with increased complexity and requires new modeling concepts to ensure the test article is delivered to a stable test condition for the programmer phase. Prompted by unexpected dynamics and hardware malfunctions in drop tests, these modeling improvements provide a more accurate loads prediction by incorporating a spring-damper line-model derived from the material properties. The qualification phase of CPAS testing is on the horizon and modeling increasingly complex test-techniques with Adams is vital to successfully qualify the Orion parachute system for human spaceflight.

Extrapolating the Trends of Test Drop Data with Opening Shock Factor Calculations: the Case of the Orion Main and Drogue Parachutes Inflating to 1st Reefed Stage

NASA Technical Reports Server (NTRS)

Potvin, Jean; Ray, Eric

2017-01-01

We describe a new calculation of the opening shock factor C (sub k) characterizing the inflation performance of NASA's Orion spacecraft main and drogue parachutes opening under a reefing constraint (1st stage reefing), as currently tested in the Capsule Parachute Assembly System (CPAS) program. This calculation is based on an application of the Momentum-Impulse Theorem at low mass ratio (R (sub m) is less than 10 (sup -1)) and on an earlier analysis of the opening performance of drogues decelerating point masses and inflating along horizontal trajectories. Herein we extend the reach of the Theorem to include the effects of payload drag and gravitational impulse during near-vertical motion - both important pre-requisites for CPAS parachute analysis. The result is a family of C (sub k) versus R (sub m) curves which can be used for extrapolating beyond the drop-tested envelope. The paper proves this claim in the case of the CPAS Mains and Drogues opening while trailing either a Parachute Compartment Drop Test Vehicle or a Parachute Test Vehicle (an Orion capsule boiler plate). It is seen that in all cases the values of the opening shock factor can be extrapolated over a range in mass ratio that is at least twice that of the test drop data.

NASA CPAS Drogue Textile Riser Feasibility Study

NASA Technical Reports Server (NTRS)

Hennings, Elsa J.; Petersen, Michael L.; Anderson, Brian; Johnson, Brian

2015-01-01

Steel cable was chosen for the lower end of the drogue and main parachute risers on NASA's Orion Multi Purpose Crew Vehicle Parachute Assembly System (CPAS) to protect the risers from extreme temperatures and abrasion should they contact the crew module during deployment, as was done for Apollo. Due to the weight and deployment complexity inherent in steel, there was significant interest in the possibility of substituting textile for steel for the drogue and main parachute risers. However, textile risers could be damaged when subjected to high temperature and abrasion. Investigations were consequently performed by a subset of the authors to determine whether sacrificial, non-load-bearing textile riser covers could be developed to mitigate the thermal and abrasion concerns. Multiple material combinations were tested, resulting in a cover design capable of protecting the riser against severe riser/crew module contact interactions. A feasibility study was then conducted to evaluate the performance of the textile drogue riser cover in relevant abrasive environments. This paper describes the testing performed and documents the results of this feasibility study.

Isolating Added Mass Load Components of CPAS Main Clusters

NASA Technical Reports Server (NTRS)

Ray, Eric S.

2017-01-01

The current simulation for the Capsule Parachute Assembly System (CPAS) lacks fidelity in representing added mass for the 116 ft Do ringsail Main parachute. The availability of 3-D models of inflating Main canopies allowed for better estimation the enclosed air volume as a function of time. This was combined with trajectory state information to estimate the components making up measured axial loads. A proof-of-concept for an alternate simulation algorithm was developed based on enclosed volume as the primary independent variable rather than drag area growth. Databases of volume growth and parachute drag area vs. volume were developed for several flight tests. Other state information was read directly from test data, rather than numerically propagated. The resulting simulated peak loads were close in timing and magnitude to the measured loads data. However, results are very sensitive to data curve fitting and may not be suitable for Monte Carlo simulations. It was assumed that apparent mass was either negligible or a small fraction of enclosed mass, with little difference in results.

Aerodynamic Reconstruction Applied to Parachute Test Vehicle Flight Data Analysis

NASA Technical Reports Server (NTRS)

Cassady, Leonard D.; Ray, Eric S.; Truong, Tuan H.

2013-01-01

The aerodynamics, both static and dynamic, of a test vehicle are critical to determining the performance of the parachute cluster in a drop test and for conducting a successful test. The Capsule Parachute Assembly System (CPAS) project is conducting tests of NASA's Orion Multi-Purpose Crew Vehicle (MPCV) parachutes at the Army Yuma Proving Ground utilizing the Parachute Test Vehicle (PTV). The PTV shape is based on the MPCV, but the height has been reduced in order to fit within the C-17 aircraft for extraction. Therefore, the aerodynamics of the PTV are similar, but not the same as, the MPCV. A small series of wind tunnel tests and computational fluid dynamics cases were run to modify the MPCV aerodynamic database for the PTV, but aerodynamic reconstruction of the flights has proven an effective source for further improvements to the database. The acceleration and rotational rates measured during free flight, before parachute inflation but during deployment, were used to con rm vehicle static aerodynamics. A multibody simulation is utilized to reconstruct the parachute portions of the flight. Aerodynamic or parachute parameters are adjusted in the simulation until the prediction reasonably matches the flight trajectory. Knowledge of the static aerodynamics is critical in the CPAS project because the parachute riser load measurements are scaled based on forebody drag. PTV dynamic damping is critical because the vehicle has no reaction control system to maintain attitude - the vehicle dynamics must be understood and modeled correctly before flight. It will be shown here that aerodynamic reconstruction has successfully contributed to the CPAS project.

Cyclopiazonic acid biosynthesis in Aspergillus sp.: characterization of a reductase-like R* domain in cyclopiazonate synthetase that forms and releases cyclo-acetoacetyl-L-tryptophan.

PubMed

Liu, Xinyu; Walsh, Christopher T

2009-09-15

The fungal neurotoxin alpha-cyclopiazonic acid (CPA), a nanomolar inhibitor of Ca2+-ATPase, has a pentacyclic indole tetramic acid scaffold that arises from one molecule of tryptophan, acetyl-CoA, malonyl-CoA, and dimethylallyl pyrophosphate by consecutive action of three enzymes, CpaS, CpaD, and CpaO. CpaS is a hybrid, two module polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) that makes and releases cyclo-acetoacetyl-L-tryptophan (cAATrp), the tetramic acid that serves as substrate for subsequent prenylation and oxidative cyclization to the five ring CPA scaffold. The NRPS module in CpaS has a predicted four-domain organization of condensation, adenylation, thiolation, and reductase* (C-A-T-R*), where R* lacks the critical Ser-Tyr-Lys catalytic triad of the short chain dehydrogenase/reductase (SDR) superfamily. By heterologous overproduction in Escherichia coli of the 56 kDa Aspergillus flavus CpaS TR* didomain and the single T and R* domains, we demonstrate that CpaS catalyzes a Dieckmann-type cyclization on the N-acetoacetyl-Trp intermediate bound in thioester linkage to the phosphopantetheinyl arm of the T domain to form and release cAATrp. This occurs without any participation of NAD(P)H, so R* does not function as a canonical SDR family member. Use of the T and R* domains in in trans assays enabled multiple turnovers and evaluation of specific mutants. Mutation of the D3803 residue in the R* domain, conserved in other fungal tetramate synthetases, abolished activity both in in trans and in cis (TR*) activity assays. It is likely that cyclization of beta-ketoacylaminoacyl-S-pantetheinyl intermediates to released tetramates represents a default cyclization/release route for redox-incompetent R* domains embedded in NRPS assembly lines.

Orion Multi-Purpose Crew Vehicle (MPCV) Capsule Parachute Assembly System (CPAS) Wake Deficit Wind Tunnel Testing

NASA Technical Reports Server (NTRS)

Ross, James C.; Schuster, David M.

2014-01-01

During descent after re-entry into the Earth's atmosphere, the Orion CM deploys its drogue parachutes at approximately Mach 0.7. Accurately predicting the dynamic pressure experienced by the drogue parachutes at deployment is critical to properly designing the parachutes. This NASA Engineering and Safety Center assessment was designed to provide a complete set of flowfield measurements on and around an idealized Orion Crew Module shape with the most appropriate wind tunnel simulation of the Orion flight conditions prior to parachute deployment. This document contains the details of testing and the outcome of the assessment.

Reconstruction of Twist Torque in Main Parachute Risers

NASA Technical Reports Server (NTRS)

Day, Joshua D.

2015-01-01

The reconstruction of twist torque in the Main Parachute Risers of the Capsule Parachute Assembly System (CPAS) has been successfully used to validate CPAS Model Memo conservative twist torque equations. Reconstruction of basic, one degree of freedom drop tests was used to create a functional process for the evaluation of more complex, rigid body simulation. The roll, pitch, and yaw of the body, the fly-out angles of the parachutes, and the relative location of the parachutes to the body are inputs to the torque simulation. The data collected by the Inertial Measurement Unit (IMU) was used to calculate the true torque. The simulation then used photogrammetric and IMU data as inputs into the Model Memo equations. The results were then compared to the true torque results to validate the Model Memo equations. The Model Memo parameters were based off of steel risers and the parameters will need to be re-evaluated for different materials. Photogrammetric data was found to be more accurate than the inertial data in accounting for the relative rotation between payload and cluster. The Model Memo equations were generally a good match and when not matching were generally conservative.

Challenges of CPAS Flight Testing

NASA Technical Reports Server (NTRS)

Ray, Eric S.; Morris, Aaron L.

2011-01-01

The Crew Exploration Vehicle Parachute Assembly System (CPAS) is being designed to land the Orion Crew Module (CM) at a safe rate of descent at splashdown via a series of Drogue, Pilot, and Main parachutes. Because Orion is considerably larger and heavier than Apollo, many of the flight test techniques developed during the Apollo program must be modified. The Apollo program had a dedicated C-133 aircraft, which was modified to allow a simple airdrop of "boilerplate" flight test vehicles. However, the CPAS program must use either commercial or military assets with minimal modifications to airframes or procedures. Conceptual envelopes from 2-Degree Of Freedom trajectories are presented for several existing and novel architectures. Ideally, the technique would deliver a representative capsule shape to the desired altitude and dynamic pressure at test initiation. However, compromises must be made on the characteristics of trajectories or the fidelity of test articles to production hardware. Most of the tests to date have used traditional pallet and weight tub or missile-shaped test vehicles. New test vehicles are being designed to better incorporate Orion structural components and deploy parachutes in a more representative fashion. The first attempt to test a capsule-shaped vehicle failed due to unexpected events while setting up the test condition through a series of complex procedures. In order to avoid the loss of another expensive test article which will delay the program, simpler deployment methods are being examined and more positive control of the vehicle will be maintained. Existing challenges include interfacing with parent aircraft, separating test vehicles, achieving test conditions, and landing within limited test ranges. All these challenges must be met within cost and schedule limits.

Activation of KV7 channels stimulates vasodilatation of human placental chorionic plate arteries.

PubMed

Mills, T A; Greenwood, S L; Devlin, G; Shweikh, Y; Robinson, M; Cowley, E; Hayward, C E; Cottrell, E C; Tropea, T; Brereton, M F; Dalby-Brown, W; Wareing, M

2015-06-01

Potassium (K(+)) channels are key regulators of vascular smooth muscle cell (VSMC) excitability. In systemic small arteries, Kv7 channel expression/activity has been noted and a role in vascular tone regulation demonstrated. We aimed to demonstrate functional Kv7 channels in human fetoplacental small arteries. Human placental chorionic plate arteries (CPAs) were obtained at term. CPA responses to Kv7 channel modulators was determined by wire myography. Presence of Kv7 channel mRNA (encoded by KCNQ1-5) and protein expression were assessed by RT-PCR and immunohistochemistry/immunofluorescence, respectively. Kv7 channel blockade with linopirdine increased CPA basal tone and AVP-induced contraction. Pre-contracted CPAs (AVP; 80 mM K(+) depolarization solution) exhibited significant relaxation to flupirtine, retigabine, the acrylamide (S)-1, and (S) BMS-204352, differential activators of Kv7.1 - Kv7.5 channels. All CPAs assessed expressed KCNQ1 and KCNQ3-5 mRNA; KCNQ2 was expressed only in a subset of CPAs. Kv7 protein expression was confirmed in intact CPAs and isolated VSMCs. Kv7 channels are present and active in fetoplacental vessels, contributing to vascular tone regulation in normal pregnancy. Targeting these channels may represent a therapeutic intervention in pregnancies complicated by increased vascular resistance. Copyright © 2015 Elsevier Ltd. All rights reserved.

Photogrammetric Analysis of CPAS Main Parachutes

NASA Technical Reports Server (NTRS)

Ray, Eric; Bretz, David

2011-01-01

The Crew Exploration Vehicle Parachute Assembly System (CPAS) is being designed to land the Orion Crew Module (CM) at a safe rate of descent at splashdown with a cluster of two to three Main parachutes. The instantaneous rate of descent varies based on parachute fly-out angles and geometric inlet area. Parachutes in a cluster oscillate between significant fly-out angles and colliding into each other. The former presents a sub-optimal inlet area and the latter lowers the effective drag area as the parachutes interfere with each other. The fly-out angles are also important in meeting a twist torque requirement. Understanding cluster behavior necessitates measuring the Mains with photogrammetric analysis. Imagery from upward looking cameras is analyzed to determine parachute geometry. Fly-out angles are measured from each parachute vent to an axis determined from geometry. Determining the scale of the objects requires knowledge of camera and lens calibration as well as features of known size. Several points along the skirt are tracked to compute an effective circumference, diameter, and inlet area as a function of time. The effects of this geometry are clearly seen in the system drag coefficient time history. Photogrammetric analysis is key in evaluating the effects of design features such as an Over-Inflation Control Line (OICL), Main Line Length Ratio (MLLR), and geometric porosity, which are varied in an attempt to minimize cluster oscillations. The effects of these designs are evaluated through statistical analysis.

Human Rating the Orion Parachute System

NASA Technical Reports Server (NTRS)

Machin, Ricardo A.; Fisher, Timothy E.; Evans, Carol T.; Stewart, Christine E.

2011-01-01

Human rating begins with design. Converging on the requirements and identifying the risks as early as possible in the design process is essential. Understanding of the interaction between the recovery system and the spacecraft will in large part dictate the achievable reliability of the final design. Component and complete system full-scale flight testing is critical to assure a realistic evaluation of the performance and reliability of the parachute system. However, because testing is so often difficult and expensive, comprehensive analysis of test results and correlation to accurate modeling completes the human rating process. The National Aeronautics and Space Administration (NASA) Orion program uses parachutes to stabilize and decelerate the Crew Exploration Vehicle (CEV) spacecraft during subsonic flight in order to deliver a safe water landing. This paper describes the approach that CEV Parachute Assembly System (CPAS) will take to human rate the parachute recovery system for the CEV.

A Status Report on the Parachute Development for NASA's Next Manned Spacecraft

NASA Technical Reports Server (NTRS)

Sinclair, Robert

2008-01-01

NASA has determined that the parachute portion of the Landing System for the Crew Exploration Vehicle (CEV) will be Government Furnished Equipment (GFE). The Earth Landing System has been designated CEV Parachute Assembly System (CPAS). Thus a program team was developed consisting of NASA Johnson Space Center (JSC) and Jacobs Engineering through their Engineering and Science Contract Group (ESCG). Following a rigorous competitive phase, Airborne Systems North America was selected to provide the parachute design, testing and manufacturing role to support this team. The development program has begun with some early flight testing of a Generation 1 parachute system. Future testing will continue to refine the design and complete a qualification phase prior to manned flight of the spacecraft. The program team will also support early spacecraft system testing, including a Pad Abort Flight Test in the Fall of 2008

Development of Capstone Project Attitude Scales

ERIC Educational Resources Information Center

Bringula, Rex P.

2015-01-01

This study attempted to develop valid and reliable Capstone Project Attitude Scales (CPAS). Among the scales reviewed, the Modified Fennema-Shermann Mathematics Attitude Scales was adapted in the construction of the CPAS. Usefulness, Confidence, and Gender View were the three subscales of the CPAS. Four hundred sixty-three students answered the…

Psychometric Properties of the Commitment to Physical Activity Scale

ERIC Educational Resources Information Center

DeBate, Rita DiGioacchino; Huberty, Jennifer; Pettee, Kelley

2009-01-01

Objective: To assess psychometric properties of the Commitment to Physical Activity Scale (CPAS). Methods: Girls in third to fifth grades (n = 932) completed the CPAS before and after a physical activity intervention. Psychometric measures included internal consistency, factor analysis, and concurrent validity. Results: Three CPAS factors emerged:…

Effects of Contamination and Cleaning on Parachute Structural Textile Elements

NASA Technical Reports Server (NTRS)

Mollmann, Catherine

2017-01-01

Throughout their lifecycle, parachute textiles come into contact with various other substances. This contact may occur during manufacturing and repair, storage and transportation, packing, or actual use. While this interaction does not always result in negative repercussions, it may cause a loss in material strength. This paper examines the strength degradation due to several contaminants as well as the effects of cleaning agents on common parachute materials. Materials tested were: Kevlar cord and webbing, Nylon broadcloth and webbing, and Vectran cord; all of these constitute the major structural elements for CPAS (Capsule Parachute Assembly System), the parachute system for the NASA Orion Crew Module. Contaminants tested were: sewing machine oil, dried stamping ink, dirt, basting glue, Sergene, and rust. Recommendations for cleaning (or not cleaning) these materials with respect to each of the contaminants are given in this paper, as well as recommendations for future tests.

Controlled loading of cryoprotectants (CPAs) to oocyte with linear and complex CPA profiles on a microfluidic platform.

PubMed

Heo, Yun Seok; Lee, Ho-Joon; Hassell, Bryan A; Irimia, Daniel; Toth, Thomas L; Elmoazzen, Heidi; Toner, Mehmet

2011-10-21

Oocyte cryopreservation has become an essential tool in the treatment of infertility by preserving oocytes for women undergoing chemotherapy. However, despite recent advances, pregnancy rates from all cryopreserved oocytes remain low. The inevitable use of the cryoprotectants (CPAs) during preservation affects the viability of the preserved oocytes and pregnancy rates either through CPA toxicity or osmotic injury. Current protocols attempt to reduce CPA toxicity by minimizing CPA concentrations, or by minimizing the volume changes via the step-wise addition of CPAs to the cells. Although the step-wise addition decreases osmotic shock to oocytes, it unfortunately increases toxic injuries due to the long exposure times to CPAs. To address limitations of current protocols and to rationally design protocols that minimize the exposure to CPAs, we developed a microfluidic device for the quantitative measurements of oocyte volume during various CPA loading protocols. We spatially secured a single oocyte on the microfluidic device, created precisely controlled continuous CPA profiles (step-wise, linear and complex) for the addition of CPAs to the oocyte and measured the oocyte volumetric response to each profile. With both linear and complex profiles, we were able to load 1.5 M propanediol to oocytes in less than 15 min and with a volumetric change of less than 10%. Thus, we believe this single oocyte analysis technology will eventually help future advances in assisted reproductive technologies and fertility preservation.

Reconstruction of Orion Engineering Development Unit (EDU) Parachute Inflation Loads

NASA Technical Reports Server (NTRS)

Ray, Eric S.

2013-01-01

The process of reconstructing inflation loads of Capsule Parachute Assembly System (CPAS) has been updated as the program transitioned to testing Engineering Development Unit (EDU) hardware. The equations used to reduce the test data have been re-derived based on the same physical assumptions made by simulations. Due to instrumentation challenges, individual parachute loads are determined from complementary accelerometer and load cell measurements. Cluster inflations are now simulated by modeling each parachute individually to better represent different inflation times and non-synchronous disreefing. The reconstruction procedure is tailored to either infinite mass or finite mass events based on measurable characteristics from the test data. Inflation parameters are determined from an automated optimization routine to reduce subjectivity. Infinite mass inflation parameters have been re-defined to avoid unrealistic interactions in Monte Carlo simulations. Sample cases demonstrate how best-fit inflation parameters are used to generate simulated drag areas and loads which favorably agree with test data.

Profile of the California Partnership Academies 2009-2010

ERIC Educational Resources Information Center

Dayton, Charles; Hamilton Hester, Candace; Stern, David

2011-01-01

State legislation launched the California Partnership Academies (CPAs) in 1984. CPAs exemplify the career academy model for preparing high school students to succeed in both college and careers. Career academies are small learning communities within larger high schools, usually enrolling students in grades 10-12. Each year students take classes…

A Profile of the California Partnership Academies, 2004-2005

ERIC Educational Resources Information Center

ConnectEd: The California Center for College and Career, 2007

2007-01-01

State legislation launched the California Partnership Academies (CPAs) in 1984. Now operating in more than 200 comprehensive high schools, CPAs have been used as a model for high school reform in California and elsewhere. Academies typically feature multi-age learning groups, team teaching and career-based instruction. Teachers help students…

Longitudinal Description of Students in California Partnership Academies

ERIC Educational Resources Information Center

Stern, David; Saroyan, Phil; Hamilton Hester, Candace

2013-01-01

This is the third in a series of three reports analyzing data on students in California Partnership Academies (CPAs). The first, "Profile of the California Partnership Academies, 2009-2010," gave an overview of California Partnerships Academies (CPAs), and included some comparisons between CPA students and all high school students in…

Career Integration in the Public Accounting Profession

ERIC Educational Resources Information Center

Ras, Gerard J. M.

2008-01-01

This paper seeks to solve the labor shortage in the public accounting profession. It examines why people want to become CPAs, the influence of generational differences on career choices and considers methods to attract and retain CPAs that focus on attracting students, work-life balance issues and alternative work arrangements through career…

Determination of Parachute Joint Factors using Seam and Joint Testing

NASA Technical Reports Server (NTRS)

Mollmann, Catherine

2015-01-01

This paper details the methodology for determining the joint factor for all parachute components. This method has been successfully implemented on the Capsule Parachute Assembly System (CPAS) for the NASA Orion crew module for use in determining the margin of safety for each component under peak loads. Also discussed are concepts behind the joint factor and what drives the loss of material strength at joints. The joint factor is defined as a "loss in joint strength...relative to the basic material strength" that occurs when "textiles are connected to each other or to metals." During the CPAS engineering development phase, a conservative joint factor of 0.80 was assumed for each parachute component. In order to refine this factor and eliminate excess conservatism, a seam and joint testing program was implemented as part of the structural validation. This method split each of the parachute structural joints into discrete tensile tests designed to duplicate the loading of each joint. Breaking strength data collected from destructive pull testing was then used to calculate the joint factor in the form of an efficiency. Joint efficiency is the percentage of the base material strength that remains after degradation due to sewing or interaction with other components; it is used interchangeably with joint factor in this paper. Parachute materials vary in type-mainly cord, tape, webbing, and cloth -which require different test fixtures and joint sample construction methods. This paper defines guidelines for designing and testing samples based on materials and test goals. Using the test methodology and analysis approach detailed in this paper, the minimum joint factor for each parachute component can be formulated. The joint factors can then be used to calculate the design factor and margin of safety for that component, a critical part of the design verification process.

Anticipatory and compensatory postural adjustments in people with low back pain: a protocol for a systematic review and meta-analysis.

PubMed

Knox, Michael F; Chipchase, Lucy S; Schabrun, Siobhan M; Marshall, Paul W M

2016-04-16

Anticipatory (APAs) and compensatory (CPAs) postural adjustments are organised by the central nervous system (CNS) and serve to control postural perturbations. Ineffective APAs and CPAs have been hypothesised to contribute to the persistence of symptoms and disability in people with low back pain (LBP). Despite two decades of research, there is no systematic review investigating APAs and CPAs in people with LBP. Thus, the aim of the current review is to determine if APA and CPA onset or amplitude, as measured by electromyography (EMG), centre of pressure (COP), and kinematics, are altered in people with LBP. A systematic review and meta-analysis will be conducted. Searches will be conducted in electronic databases for full-text articles published before January 2016 using pre-defined search strategies that utilise combinations of keywords and medical subject heading terms. Two independent reviewers will screen potentially relevant articles for inclusion, extract data, and assess risk of bias for individual studies. Any disagreements will be resolved by a third reviewer. Studies comparing APA onset and amplitude and CPA onset and amplitude measured by EMG, COP, or kinematics between people with LBP and healthy individuals will be included if all aspects of the eligibility criteria are met. Data will be synthesised if studies are homogeneous; otherwise, results will be reviewed narratively. To our knowledge, this is the first systematic review to examine APAs and CPAs, as measured by EMG, COP, and kinematics in people with LBP. The findings of this review may aid in the identification of factors that play a role in the persistence of symptoms and disability and aid in the development of interventions to treat symptoms. PROSPERO CRD42016032815.

Beliefs of Certified Public Accountants toward Distance Education: A Statewide Georgia Survey.

ERIC Educational Resources Information Center

Perdue, Kathy J.; Valentine, Thomas

1998-01-01

Examines the beliefs of certified public accountants (CPAs) in the state of Georgia concerning the effectiveness of distance education in providing continuing professional education (CPE). Findings indicate that the CPAs believe distance education to be an effective mode of learning, and that necessary technological capabilities are available to…

A Paradigm Shift toward Evidence-Based Clinical Practice: Developing a Performance Assessment

ERIC Educational Resources Information Center

Wentworth, Nancy; Erickson, Lynnette B.; Lawrence, Barbara; Popham, J. Aaron; Korth, Byran

2009-01-01

The Clinical Practice Assessment System (CPAS), developed in response to teacher preparation program accreditation requirements, represents a paradigm shift of one university toward data-based decision-making in teacher education programs. The new assessment system is a scale aligned with INTASC Standards, which allows for observation and…

Communication, Litigation, and Financial Auditing: Grady Hazel's Views

ERIC Educational Resources Information Center

Ramsey, Richard David

2007-01-01

This article reports the substance of an interview with Grady R. Hazel, Executive Director of the Society of Louisiana Certified Public Accountants (CPAs). Hazel has been director of the Society of Louisiana CPAs since 1995. The 6,500-member organization is headquartered in Kenner, a suburb of New Orleans. A native of Baton Rouge, Hazel has been…

Vitreous Cryopreservation of Human Umbilical Vein Endothelial Cells with Low Concentration of Cryoprotective Agents for Vascular Tissue Engineering

PubMed Central

Zheng, Yuanyuan; Panhwar, Fazil

2016-01-01

Cryopreservation of human umbilical vein endothelial cells (HUVECs) is important to tissue engineering applications and the study of the role of endothelial cells in cardiovascular and cerebrovascular diseases. The traditional methods for cryopreservation by vitrification (cooling samples to a cryogenic temperature without apparent freezing) using high concentration of cryoprotective agents (CPAs) and slow freezing are suboptimal due to the severe toxicity of high concentration of CPAs and ice formation-induced cryoinjuries, respectively. In this study, we developed a method to cryopreserve HUVECs by vitrification with low concentration of CPAs. This is achieved by optimizing the CPAs and using highly thermally conductive quartz capillary (QC) to contain samples for vitrification. The latter minimizes the thermal mass to create ultra-fast cooling/warming rates. Our data demonstrate that HUVECs can be vitrified in the QC using 1.4 mol/L ethylene glycol and 1.1 mol/L dimethyl sulfoxide with more than 90% viability. Moreover, this method significantly improves the attachment efficiency of the cryopreserved HUVECs. The attached cells post-cryopreservation proliferate similarly to fresh cells. Therefore, this study may provide an effective vitrification technique to bank HUVECs for vascular tissue engineering and other applications. PMID:27673413

Cryoprotectant Toxicity: Facts, Issues, and Questions

PubMed Central

2015-01-01

Abstract High levels of penetrating cryoprotectants (CPAs) can eliminate ice formation during cryopreservation of cells, tissues, and organs to cryogenic temperatures. But CPAs become increasingly toxic as concentration increases. Many strategies have been attempted to overcome the problem of eliminating ice while minimizing toxicity, such as attempting to optimize cooling and warming rates, or attempting to optimize time of adding individual CPAs during cooling. Because strategies currently used are not adequate, CPA toxicity remains the greatest obstacle to cryopreservation. CPA toxicity stands in the way of cryogenic cryopreservation of human organs, a procedure that has the potential to save many lives. This review attempts to describe what is known about CPA toxicity, theories of CPA toxicity, and strategies to reduce CPA toxicity. Critical analysis and suggestions are also included. PMID:25826677

Evaluation and application of a passive air sampler for polycylic aromatic hydrocarbons (PAHs).

PubMed

Esen, Fatma; Evci, Yildiz M; Tasdemir, Yucel

2017-08-24

Sampling of 15 PAHs by the use of both passive air sampler developed (D-PAS) in our research group and PAS (C-PAS) having widespread use in the literature was conducted to compare the performances of the samplers. Sampling was carried out for 1-year period (February 2013-February 2014), in different sampling periods by employing D-PAS and C-PAS. D-PAS and C-PAS were run in parallel for 10, 20, 30, 40 and 60 days. Sampling rates were calculated for both PASs by the use of concentration values obtained from a high-volume air sampler (HVAS). It was determined that calculated sampling values are different from each other by definition of design of C-PAS and D-PAS and difference in environment as velocity of wind and temperature are having different effects upon sampling rates. Collected σ 15 PAHs amounts of 10-day periods in spring, summer, autumn and winter were obtained as 576 ± 333, 209 ± 29, 2402 ± 910 and 664 ± 246 ng for D-PAS and 1070 ± 522, 318 ± 292, 6062 ± 1501 and 6089 ± 4018 ng for C-PAS, respectively. In addition, according to seasons, when collected PAHs in two different samplers were considered, similar results were obtained for the summer time in which no combustion takes place with the aim of domestic heating, while there were differences determined for the seasons with combustion in need of domestic heating. Gas-phase σ 15 PAHs' concentrations were reported depending on seasons in the spring, summer, autumn and winter sequences as 46 ± 32, 9 ± 3, 367 ± 207 and 127 ± 93 ng m -3 for HVAS, respectively.

Characterization of cyclo-Acetoacetyl-L-Tryptophan Dimethylallyltransferase in Cyclopiazonic Acid Biosynthesis: Substrate Promiscuity and Site Directed Mutagenesis Studies

PubMed Central

Liu, Xinyu; Walsh, Christopher T.

2009-01-01

The fungal neurotoxin α-cyclopiazonic acid (CPA), a nanomolar inhibitor of Ca2+-ATPase with a unique pentacyclic indole tetramic acid scaffold is assembled by a three enzyme pathway CpaS, CpaD and CpaO in Aspergillus sp. We recently characterized the first pathway-specific enzyme CpaS, a hybrid two module polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) that generates cyclo-acetoacetyl-L-tryptophan (cAATrp). Here we report the characterization of the second pathway-specific enzyme CpaD that regiospecifically dimethylallylates cAATrp to form β-cyclopiazonic acid. By exploring the tryptophan and tetramate moieties of cAATrp, we demonstrate that CpaD discriminates against free Trp but accepts tryptophan-containing thiohydantoins, diketopiperazines and linear peptides as substrates for C4-prenylation and also acts as regiospecific O-dimethylallyltransferase (DMAT) on a tyrosine-derived tetramic acid. Comparative evaluation of CpaDs from A. oryzae RIB40 and A. flavus NRRL3357 indicated the importance of the N-terminal region for its activity. Sequence alignment of CpaD with eleven homologous fungal Trp-DMATs revealed five regions of conservation suggesting the presense of critical motifs that could be diagonostic for discovering additional Trp-DMATs. Subsequent site-directed mutagenesis studies identified five polar/charged residues and five tyrosine residues within these motifs that are critical for CpaD activity. This motif characerization will enable a gene probe-based approach to discover additional biosynthetic Trp-DMATs. PMID:19877600

Formative Assessment for College Readiness: Measuring Skill and Growth in Five Key Cognitive Strategies Associated with Postsecondary Success

ERIC Educational Resources Information Center

Conley, David; Lombardi, Allison; Seburn, Mary; McGaughy, Charis

2009-01-01

This study reports the preliminary results from a field test of the College-readiness Performance Assessment System (C-PAS), a large-scale, 6th-12th grade criterion-referenced assessment system that utilizes classroom-embedded performance tasks to measure student progress toward the development of key cognitive skills associated with success in…

Compensatory but not anticipatory adjustments are altered in older adults during lateral postural perturbations.

PubMed

Claudino, Renato; dos Santos, Eloá C C; Santos, Marcio J

2013-08-01

This study investigated anticipatory postural adjustments (APAs) and compensatory postural adjustments (CPAs) and their relationship in older adults during lateral postural perturbations. Unpredictable and predictable postural disturbances were induced by a swinging pendulum that impacted at the shoulder level of two groups of older adults, non-fallers (20) and fallers (20), and in a group of young control subjects (20). The electromyographic (EMG) activity of the postural muscles and the center of pressure (COP) displacement were recorded and quantified within the time intervals typical for APAs and CPAs. Both groups of older adults (non-fallers and fallers) showed higher magnitude of EMG activity in the lateral muscles and increased COP displacement, particularly, during the CPAs time interval when compared to the young group. Older adults, however, were able to change the electrical activity of the muscles during the predictable task by generating APAs with similar magnitudes of those found in young subjects. Compensatory but not anticipatory adjustments are altered in older adults during predictable lateral postural perturbations. These findings provide new data on the role of APAs and CPAs in their relationship in older adults during external lateral perturbations and may advance current rehabilitative management strategies to improve balance control in older individuals. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

The economic efficiency of conservation measures for amphibians in organic farming--results from bio-economic modelling.

PubMed

Schuler, Johannes; Sattler, Claudia; Helmecke, Angela; Zander, Peter; Uthes, Sandra; Bachinger, Johann; Stein-Bachinger, Karin

2013-01-15

This paper presents a whole farm bio-economic modelling approach for the assessment and optimisation of amphibian conservation conditions applied at the example of a large scale organic farm in North-Eastern Germany. The assessment focuses mainly on the habitat quality as affected by conservation measures such as through specific adapted crop production activities (CPA) and in-field buffer strips for the European tree frog (Hyla arborea), considering also interrelations with other amphibian species (i.e. common spadefoot toad (Pelobates fuscus), fire-bellied toad (Bombina bombina)). The aim of the approach is to understand, analyse and optimize the relationships between the ecological and economic performance of an organic farming system, based on the expectation that amphibians are differently impacted by different CPAs. The modelling system consists of a set of different sub-models that generate a farm model on the basis of environmentally evaluated CPAs. A crop-rotation sub-model provides a set of agronomically sustainable crop rotations that ensures overall sufficient nitrogen supply and controls weed, pest and disease infestations. An economic sub-model calculates the gross margins for each possible CPA including costs of inputs such as labour and machinery. The conservation effects of the CPAs are assessed with an ecological sub-model evaluates the potential negative or positive effect that each work step of a CPA has on amphibians. A mathematical programming sub-model calculates the optimal farm organization taking into account the limited factors of the farm (e.g. labour, land) as well as ecological improvements. In sequential model runs, the habitat quality is to be improved by the model, while the highest possible gross margin is still to be achieved. The results indicate that the model can be used to show the scope of action that a farmer has to improve habitat quality by reducing damage to amphibian population on its land during agricultural activities. Thereby, depending on the level of habitat quality that is aimed at, different measures may provide the most efficient solution. Lower levels of conservation can be achieved with low-cost adapted CPAs, such as an increased cutting height, reduced sowing density and grubbing instead of ploughing. Higher levels of conservation require e.g. grassland-like managed buffer strips around ponds in sensible areas, which incur much higher on-farm conservation costs. Copyright © 2012 Elsevier Ltd. All rights reserved.

U.S. Accounting Education: Misalignment with the Needs of Small and Medium Companies

ERIC Educational Resources Information Center

Burke, Megan M.; Gandolfi, William R.

2014-01-01

This study looks to answer the question, "Does the current accounting educational system in the United States focus too heavily on the requirements of large (and SEC registered) companies at the expense of small companies and individuals who comprise the primary clientele of most practicing CPAs?" This investigation surveys CPAs…

Natural zwitterionic l-Carnitine as efficient cryoprotectant for solvent-free cell cryopreservation.

PubMed

Zhai, Hongwen; Yang, Jing; Zhang, Jiamin; Pan, Chao; Cai, Nana; Zhu, Yingnan; Zhang, Lei

2017-07-15

Organic solvents, such as dimethyl sulfoxide (DMSO) and glycerol, have been commonly used as cryoprotectants (CPAs) in cell cryopreservation. However, their cytotoxicity and need of complex freezing protocols have impeded their applications especially in clinical cell therapy and regenerative medicine. Trehalose has been explored as a natural CPA to cryopreserve cells, but its poor cell permeability frequently results in low cryopreservation efficacy. In this work, we presented that a natural zwitterionic molecule-l-carnitine-could serve as a promising CPA for solvent-free cryopreservation. We demonstrated that l-carnitine possessed strong ability to depress water freezing point, and with ultrarapid freezing protocol, we studied the post-thaw survival efficiency of four cell lines (GLC-82 cells, MCF-7 cells, NIH-3T3 cells and Sheep Red Blood Cells) using l-carnitine without addition of any organic solvents. At the optimum l-carnitine concentration, all four cell lines could achieve above 80% survival efficiency, compared with the significantly lower efficiency using organic CPAs and trehalose. After cryopreservation, the recovered cell behaviors including cell attachment and proliferation were found to be similar to the normal cells, indicating that the cell functionalities were not affected. Moreover, l-carnitine showed no observable cytotoxicity, which was superior to the organic CPAs. This work offered an attractive alternative to traditional CPAs and held great promise to revolutionize current cryopreservation technologies, to benefit the patients in various cell-based clinical applications. Copyright © 2017 Elsevier Inc. All rights reserved.

Utilization of Collaborative Practice Agreements between Physicians and Pharmacists as a Mechanism to Increase Capacity to Care for Hematopoietic Stem Cell Transplant Recipients

PubMed Central

Merten, Julianna A.; Shapiro, Jamie F.; Gulbis, Alison M.; Rao, Kamakshi V.; Bubalo, Joseph; Lanum, Scott; Engemann, Ashley Morris; Shayani, Sepideh; Williams, Casey; Leather, Helen; Walsh-Chocolaad, Tracey

2013-01-01

Survival following hematopoietic stem cell transplantation (HSCT) has improved and the number of allogeneic HSCTs performed annually in the United States is expected to reach 10,000 by 2015. The National Marrow Donor Program created the System Capacity Initiative to formulate mechanisms to care for the growing number of HSCT recipients. One proposed method to increase capacity is utilization of pharmacists to manage drug therapy via collaborative practice agreements (CPAs). Pharmacists have managed drug therapy in oncology patients with CPAs for decades; however, there are limited HSCT centers that employ this practice. Engaging in collaborative practice and billing agreements with credentialed pharmacists to manage therapeutic drug monitoring, chronic medical conditions and supportive care in HSCT recipients may be cost-effective and enable physicians to spend more time on new or more complex patients. The goal of this paper is to provide a framework for implementation of a CPA and address how it may improve HSCT program capacity. PMID:23419976

Structural evidence of the species-dependent albumin binding of the modified cyclic phosphatidic acid with cytotoxic properties

PubMed Central

Sekula, Bartosz; Ciesielska, Anna; Rytczak, Przemyslaw; Koziołkiewicz, Maria; Bujacz, Anna

2016-01-01

Cyclic phosphatidic acids (cPAs) are naturally occurring, very active signalling molecules, which are involved in several pathological states, such as cancer, diabetes or obesity. As molecules of highly lipidic character found in the circulatory system, cPAs are bound and transported by the main extracellular lipid binding protein–serum albumin. Here, we present the detailed interactions between human serum albumin (HSA) and equine serum albumin (ESA) with a derivative of cPA, 1-O-myristoyl-sn-glycerol-2,3-cyclic phosphorodithioate (Myr-2S-cPA). Initial selection of the ligand used for the structural study was made by the analysis of the therapeutically promising properties of the sulfur containing analogues of cPA in respect to the unmodified lysophospholipids (LPLs). Substitution of one or two non-bridging oxygen atoms in the phosphate group with one or two sulfur atoms increases the cytotoxic effect of cPAs up to 60% on the human prostate cancer (PC) cells. Myr-2S-cPA reduces cancer cell viability in a dose-dependent manner, with IC50 value of 29.0 μM after 24 h incubation, which is almost 30% lower than IC50 of single substituted phosphorothioate cPA. Although, the structural homology between HSA and ESA is big, their crystal complexes with Myr-2S-cPA demonstrate significantly different mode of binding of this LPL analogue. HSA binds three molecules of Myr-2S-cPA, whereas ESA only one. Moreover, none of the identified Myr-2S-cPA binding sites overlap in both albumins. PMID:27129297

Three components of postural control associated with pushing in symmetrical and asymmetrical stance.

PubMed

Lee, Yun-Ju; Aruin, Alexander S

2013-07-01

A number of occupational and leisure activities that involve pushing are performed in symmetrical or asymmetrical stance. The goal of this study was to investigate early postural adjustments (EPAs), anticipatory postural adjustments (APAs), and compensatory postural adjustments (CPAs) during pushing performed while standing. Ten healthy volunteers stood in symmetrical stance (with feet parallel) or in asymmetrical stance (staggered stance with one foot forward) and were instructed to use both hands to push forward the handle of a pendulum attached to the ceiling. Bilateral EMG activity of the trunk and leg muscles and the center of pressure (COP) displacements in the anterior-posterior (AP) and medial-lateral (ML) directions were recorded and analyzed during the EPAs, APAs, and CPAs. The EMG activity and the COP displacement were different between the symmetrical and asymmetrical stance conditions. The COP displacements in the ML direction were significantly larger in staggered stance than in symmetrical stance. In staggered stance, the EPAs and APAs in the thigh muscles of the backward leg were significantly larger, and the CPAs were smaller than in the forward leg. There was no difference in the EMG activity of the trunk muscles between the stance conditions. The study outcome confirmed the existence of the three components of postural control (EPAs, APAs, and CPAs) in pushing. Moreover, standing asymmetrically was associated with asymmetrical patterns of EMG activity in the lower extremities reflecting the stance-related postural control during pushing. The study outcome provides a basis for studying postural control during other daily activities involving pushing.

Timing of androgen receptor disruption and estrogen exposure underlies a spectrum of congenital penile anomalies

PubMed Central

Armfield, Brooke A.; Cohn, Martin J.

2015-01-01

Congenital penile anomalies (CPAs) are among the most common human birth defects. Reports of CPAs, which include hypospadias, chordee, micropenis, and ambiguous genitalia, have risen sharply in recent decades, but the causes of these malformations are rarely identified. Both genetic anomalies and environmental factors, such as antiandrogenic and estrogenic endocrine disrupting chemicals (EDCs), are suspected to cause CPAs; however, little is known about the temporal window(s) of sensitivity to EDCs, or the tissue-specific roles and downstream targets of the androgen receptor (AR) in external genitalia. Here, we show that the full spectrum of CPAs can be produced by disrupting AR at different developmental stages and in specific cell types in the mouse genital tubercle. Inactivation of AR during a narrow window of prenatal development results in hypospadias and chordee, whereas earlier disruptions cause ambiguous genitalia and later disruptions cause micropenis. The neonatal phase of penile development is controlled by the balance of AR to estrogen receptor α (ERα) activity; either inhibition of androgen or augmentation of estrogen signaling can induce micropenis. AR and ERα have opposite effects on cell division, apoptosis, and regulation of Hedgehog, fibroblast growth factor, bone morphogenetic protein, and Wnt signaling in the genital tubercle. We identify Indian hedgehog (Ihh) as a novel downstream target of AR in external genitalia and show that conditional deletion of Ihh inhibits penile masculinization. These studies reveal previously unidentified cellular and molecular mechanisms by which antiandrogenic and estrogenic signals induce penile malformations and demonstrate that the timing of endocrine disruption can determine the type of CPA. PMID:26598695

Structural evidence of the species-dependent albumin binding of the modified cyclic phosphatidic acid with cytotoxic properties.

PubMed

Sekula, Bartosz; Ciesielska, Anna; Rytczak, Przemyslaw; Koziołkiewicz, Maria; Bujacz, Anna

2016-07-01

Cyclic phosphatidic acids (cPAs) are naturally occurring, very active signalling molecules, which are involved in several pathological states, such as cancer, diabetes or obesity. As molecules of highly lipidic character found in the circulatory system, cPAs are bound and transported by the main extracellular lipid binding protein-serum albumin. Here, we present the detailed interactions between human serum albumin (HSA) and equine serum albumin (ESA) with a derivative of cPA, 1-O-myristoyl-sn-glycerol-2,3-cyclic phosphorodithioate (Myr-2S-cPA). Initial selection of the ligand used for the structural study was made by the analysis of the therapeutically promising properties of the sulfur containing analogues of cPA in respect to the unmodified lysophospholipids (LPLs). Substitution of one or two non-bridging oxygen atoms in the phosphate group with one or two sulfur atoms increases the cytotoxic effect of cPAs up to 60% on the human prostate cancer (PC) cells. Myr-2S-cPA reduces cancer cell viability in a dose-dependent manner, with IC50 value of 29.0 μM after 24 h incubation, which is almost 30% lower than IC50 of single substituted phosphorothioate cPA. Although, the structural homology between HSA and ESA is big, their crystal complexes with Myr-2S-cPA demonstrate significantly different mode of binding of this LPL analogue. HSA binds three molecules of Myr-2S-cPA, whereas ESA only one. Moreover, none of the identified Myr-2S-cPA binding sites overlap in both albumins. © 2016 The Author(s).

Pendulum Motion in Main Parachute Clusters

NASA Technical Reports Server (NTRS)

Ray, Eric S.; Machin, Ricardo A.

2015-01-01

The coupled dynamics of a cluster of parachutes to a payload are notoriously difficult to predict. Often the payload is designed to be insensitive to the range of attitude and rates that might occur, but spacecraft generally do not have the mass and volume budgeted for this robust of a design. The National Aeronautics and Space Administration (NASA) Orion Capsule Parachute Assembly System (CPAS) implements a cluster of three mains for landing. During testing of the Engineering Development Unit (EDU) design, it was discovered that with a cluster of two mains (a fault tolerance required for human rating) the capsule coupled to the parachute cluster could get into a limit cycle pendulum motion which would exceed the spacecraft landing capability. This pendulum phenomenon could not be predicted with the existing models and simulations. A three phased effort has been undertaken to understand the consequence of the pendulum motion observed, and explore potential design changes that would mitigate this phenomenon. This paper will review the early analysis that was performed of the pendulum motion observed during EDU testing, summarize the analysis ongoing to understand the root cause of the pendulum phenomenon, and discuss the modeling and testing that is being pursued to identify design changes that would mitigate the risk.

Extraction-Separation Performance and Dynamic Modeling of Orion Test Vehicles with Adams Simulation: 3rd Edition

NASA Technical Reports Server (NTRS)

Varela, Jose G.; Reddy, Satish; Moeller, Enrique; Anderson, Keith

2017-01-01

NASA's Orion Capsule Parachute Assembly System (CPAS) Project is now in the qualification phase of testing, and the Adams simulation has continued to evolve to model the complex dynamics experienced during the test article extraction and separation phases of flight. The ability to initiate tests near the upper altitude limit of the Orion parachute deployment envelope requires extractions from the aircraft at 35,000 ft-MSL. Engineering development phase testing of the Parachute Test Vehicle (PTV) carried by the Carriage Platform Separation System (CPSS) at altitude resulted in test support equipment hardware failures due to increased energy caused by higher true airspeeds. As a result, hardware modifications became a necessity requiring ground static testing of the textile components to be conducted and a new ground dynamic test of the extraction system to be devised. Force-displacement curves from static tests were incorporated into the Adams simulations, allowing prediction of loads, velocities and margins encountered during both flight and ground dynamic tests. The Adams simulation was then further refined by fine tuning the damping terms to match the peak loads recorded in the ground dynamic tests. The failure observed in flight testing was successfully replicated in ground testing and true safety margins of the textile components were revealed. A multi-loop energy modulator was then incorporated into the system level Adams simulation model and the effect on improving test margins be properly evaluated leading to high confidence ground verification testing of the final design solution.

Strength Variation of Parachute Joints

NASA Technical Reports Server (NTRS)

Mollmann, Catherine

2017-01-01

A parachute joint is defined as a location where a component is sewn or connected to another component. During the design and developmental phase of a parachute system, the joints for each structural component are isolated and tested through a process called seam and joint testing. The objective of seam and joint testing is to determine the degradation on a single component due to interaction with other components; this data is then used when calculating the margin of safety for that component. During the engineering developmental phase of CPAS (Capsule Parachute Assembly System), the parachute system for the NASA Orion Crew Module, testing was completed for every joint of the six subsystems: the four parachutes (main, drogue, pilot, and FBCP [forward bay cover parachute]), the retention release bridle, and the retention panels. The number of joint tests for these subsystems totaled 92, which provides a plethora of data and results for further analysis. In this paper, the data and results of these seam and joint tests are examined to determine the effects, if any, of different operators and sewing machines on the strength of parachute joints. Other variables are also studied to determine their effect on joint strength, such as joint complexity, joint strength magnitude, material type, and material construction. Findings reveal that an optimally-run seam and joint test program could result in an increased understanding of the structure of the parachute; this should lead to a parachute built with optimal components, potentially saving system weight and volume.

Breast Cancer Chemoprevention: A Network Meta-Analysis of Randomized Controlled Trials.

PubMed

Mocellin, Simone; Pilati, Pierluigi; Briarava, Marta; Nitti, Donato

2016-02-01

Several agents have been advocated for breast cancer primary prevention. However, few of them appear effective, the associated severe adverse effects limiting their uptake. We performed a comprehensive search for randomized controlled trials (RCTs) reporting on the ability of chemoprevention agents (CPAs) to reduce the incidence of primary breast carcinoma. Using network meta-analysis, we ranked CPAs based simultaneously on efficacy and acceptability (an inverse measure of toxicity). All statistical tests were two-sided. We found 48 eligible RCTs, enrolling 271 161 women randomly assigned to receive either placebo or one of 21 CPAs. Aromatase inhibitors (anastrozole and exemestane, considered a single CPA class because of the lack of between-study heterogeneity; relative risk [RR] = 0.468, 95% confidence interval [CI] = 0.346 to 0.634), arzoxifene (RR = 0.415, 95% CI = 0.253 to 0.682), lasofoxifene (RR = 0.208, 95% CI = 0.079 to 0.544), raloxifene (RR = 0.572, 95% CI = 0.372 to 0.881), tamoxifen (RR = 0.708, 95% CI = 0.595 to 0.842), and tibolone (RR = 0.317, 95% CI = 0.127 to 0.792) were statistically significantly associated with a therapeutic effect, which was restricted to estrogen receptor-positive tumors of postmenopausal women (except for tamoxifen, which is active also during premenopause). Network meta-analysis ranking showed that the new selective estrogen receptor modulators (SERMs) arzoxifene, lasofoxifene, and raloxifene have the best benefit-risk ratio. Aromatase inhibitors and tamoxifen ranked second and third, respectively. These results provide physicians and health care regulatory agencies with RCT-based evidence on efficacy and acceptability of currently available breast cancer CPAs; at the same time, we pinpoint how much work still remains to be done before pharmacological primary prevention becomes a routine option to reduce the burden of this disease. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Association of Streptococcus pneumoniae common protein antigen (CPA) antibodies and pneumococcal nasopharyngeal colonization in HIV-infected and HIV-uninfected African children.

PubMed

Ditse, Z; Adrian, P V; Kuwanda, L; Madhi, S A

2013-09-13

Due to the high cost and limited serotype coverage of pneumococcal conjugate vaccines (PCV), pneumococcal common protein antigens (CPAs) are being investigated as potential vaccine candidates. CPAs are likely to be immunogenic in infants and could confer serotype-independent protection. There are limited data on natural antibody kinetics against CPAs in African populations. We aimed to determine the prevalence of naturally acquired antibody titres to 15 CPAs and explore their association to concurrent pneumococcal nasopharyngeal colonization in children aged 4-7 years with and without underlying HIV-infection and/or previous PCV-vaccination. A 15-plex Luminex assay was established to measure serum IgG titres against "cell-wall associated or surface-exposed" proteins (PspA, PspC, LytB, IgA1-proteinase, SP0082, PdB and PcsB), "membrane-associated" proteins (PsaA, SP0609, SP0749, PpmA, SlrA, StkP and SP2194) as well as the hypothetical protein, SP2027. Archived serum samples from HIV-uninfected (n=212) and HIV-infected (n=74) children were analyzed. Concurrent pneumococcal nasopharyngeal colonization was determined with standard microbiological methods. HIV-uninfected children had significantly higher antibody titres against PspA, PspC, PdB, SP0082, LytB, IgA1 proteinase and PcsB compared to HIV-infected children. In contrast, antibody titres against membrane associated proteins (PsaA, SP2027, PpmA and SlrA) were significantly lower in HIV-uninfected compared to HIV-infected children. Higher antibody titres against PdB, and PcsB were associated with the absence of pneumococcal colonization. There was no association between anti-CPA titres and PCV vaccination. In conclusion PdB and PcsB antigens are potential vaccine-candidates which may protect against pneumococcal colonization and consequently pneumococcal disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

Numerical investigations of transient heat transfer characteristics and vitrification tendencies in ultra-fast cell cooling processes.

PubMed

Jiao, Anjun; Han, Xu; Critser, John K; Ma, Hongbin

2006-06-01

During freezing, cells are often damaged directly or indirectly by ice formation. Vitrification is an alternative approach to cryopreservation that avoids ice formation. The common method to achieve vitrification is to use relatively high concentrations of cryoprotectant agents (CPA) in combination with a relatively slow cooling rate. However, high concentrations of CPAs have potentially damaging toxic and/or osmotic effects on cells. Therefore, establishing methods to achieve vitrification with lower concentrations of CPAs through ultra-fast cooling rates would be advantageous in these aspects. These ultra-fast cooling rates can be realized by a cooling system with an ultra-high heat transfer coefficient (h) between the sample and coolant. The oscillating motion heat pipe (OHP), a novel cooling device utilizing the pressure change to excite the oscillation motion of the liquid plugs and vapor bubbles, can significantly increase h and may fulfill this aim. The current investigation was designed to numerically study the effects of different values of h on the transient heat transfer characteristics and vitrification tendencies of the cell suspension during the cooling processes in an ultra-thin straw (100 microm in diameter). The transient temperature distribution, the cooling rate and the volume ratio (x) of the ice quantity to the maximum crystallizable ice of the suspension were calculated. From these numerical results, it is concluded that the ultra-high h (>10(4) W/m2 K) obtained by OHPs could facilitate vitrification by efficiently decreasing x as well as the time to pass through the dangerous temperature region where the maximum ice formation happens. For comparison, OHPs can decrease both of the parameters to less than 20% of those from the widely used open pulled straw methods. Therefore, the OHP method will be a promising approach to improving vitrification tendencies of CPA solutions and could also decrease the required concentration of CPAs for vitrification, both of which are of great importance for the successful cryopreservation of cells by vitrification.

[INVITED] Coherent perfect absorption of electromagnetic wave in subwavelength structures

NASA Astrophysics Data System (ADS)

Yan, Chao; Pu, Mingbo; Luo, Jun; Huang, Yijia; Li, Xiong; Ma, Xiaoliang; Luo, Xiangang

2018-05-01

Electromagnetic (EM) absorption is a common process by which the EM energy is transformed into other kinds of energy in the absorber, for example heat. Perfect absorption of EM with structures at subwavelength scale is important for many practical applications, such as stealth technology, thermal control and sensing. Coherent perfect absorption arises from the interplay of interference and absorption, which can be interpreted as a time-reversed process of lasing or EM emitting. It provides a promising way for complete absorption in both nanophotonics and electromagnetics. In this review, we discuss basic principles and properties of a coherent perfect absorber (CPA). Various subwavelength structures including thin films, metamaterials and waveguide-based structures to realize CPAs are compared. We also discuss the potential applications of CPAs.

What predictions can be made on the nature of carbon and carbon-bearing compounds (hydrocarbons) in the interstellar medium based on studies of interplanetary dust particles?

NASA Technical Reports Server (NTRS)

Rietmeijer, F. J. M.

1986-01-01

The nature of hydrocarbons and properties of elemental carbon in circumstellar, interstellar, and interplanetary dust is a long standing problem in astronomy and meteorite research. The textures and crystallographical properties of poorly graphitized carbon (PGC) from carbonaceous chondrites and Chondritic Porous Aggregates (CPAs) are comparable with PGCs formed by dehydrogenation and carbonization of hydrocarbon precursors under natural terrestrial and experimental conditions. A multistage model of hydrocarbon diagenesis in CPA and carbonaceous chondrite (proto-) planetary parent bodies was proposed in which hydrocarbons are subjected to low temperature hydrous pyrolysis. Continued efforts to recognize hydrocarbons and elemental phases in CPAs may allow understanding of the multistage hydrocarbon/elemental carbon model.

Isolated and combined effects of asymmetric stance and pushing movement on the anticipatory and compensatory postural control.

PubMed

Lee, Yun-Ju; Aruin, Alexander S

2014-04-01

To investigate effects of symmetric and asymmetric stance and pushing movement on anticipatory and compensatory postural adjustments (APAs and CPAs). Ten healthy volunteers stood symmetrically (feet parallel) or asymmetrically (one foot forward and the other backward) and pushed a handle with both hands or right or left hand. Bilateral EMG activity of the trunk and leg muscles and center of pressure (COP) displacements in the anterior-posterior (AP) and medial-lateral (ML) directions were recorded and analyzed during the APAs and CPAs. Isolated asymmetry of stance was associated with larger muscle activity of the backward leg while isolated asymmetry of pushing movement induced larger trunk muscle activity on the contralateral side. A combined asymmetry of stance and pushing movement resulted in the increase or decrease of the thigh muscle activity and ML COP displacement depending on whether both asymmetries were induced on the same side of the body or on opposite sides. Both isolated and combined asymmetries affect APAs and CPAs in pushing. Using combined asymmetry of stance and arm movement might be beneficial in performing pushing activity. The outcome of the study provides a basis for studying postural control in individuals with unilateral impairment while performing daily tasks involving pushing. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Methanol-Promoted Lipid Remodelling during Cooling Sustains Cryopreservation Survival of Chlamydomonas reinhardtii

PubMed Central

Yang, Duanpeng; Li, Weiqi

2016-01-01

Cryogenic treatments and cryoprotective agents (CPAs) determine the survival rate of organisms that undergo cryopreservation, but their mechanisms of operation have not yet been characterised adequately. In particular, the way in which membrane lipids respond to cryogenic treatments and CPAs is unknown. We developed comparative profiles of the changes in membrane lipids among cryogenic treatments and between the CPAs dimethyl sulfoxide (DMSO) and methanol (MeOH) for the green alga Chlamydomonas reinhardtii. We found that freezing in liquid nitrogen led to a dramatic degradation of lipids, and that thawing at warm temperature (35°C) induced lipid remodelling. DMSO did not protect membranes, but MeOH significantly attenuated lipid degradation. The presence of MeOH during cooling (from 25°C to −55°C at a rate of 1°C/min) sustained the lipid composition to the extent that membrane integrity was maintained; this phenomenon accounts for successful cryopreservation. An increase in monogalactosyldiacylglycerol and a decrease in diacylglycerol were the major changes in lipid composition associated with survival rate, but there was no transformation between these lipid classes. Phospholipase D-mediated phosphatidic acid was not involved in freezing-induced lipid metabolism in C. reinhardtii. Lipid unsaturation changed, and the patterns of change depended on the cryogenic treatment. Our results provide new insights into the cryopreservation of, and the lipid metabolism in, algae. PMID:26731741

Extraction and Separation Modeling of Orion Test Vehicles with ADAMS Simulation

NASA Technical Reports Server (NTRS)

Fraire, Usbaldo, Jr.; Anderson, Keith; Cuthbert, Peter A.

2013-01-01

The Capsule Parachute Assembly System (CPAS) project has increased efforts to demonstrate the performance of fully integrated parachute systems at both higher dynamic pressures and in the presence of wake fields using a Parachute Compartment Drop Test Vehicle (PCDTV) and a Parachute Test Vehicle (PTV), respectively. Modeling the extraction and separation events has proven challenging and an understanding of the physics is required to reduce the risk of separation malfunctions. The need for extraction and separation modeling is critical to a successful CPAS test campaign. Current PTV-alone simulations, such as Decelerator System Simulation (DSS), require accurate initial conditions (ICs) drawn from a separation model. Automatic Dynamic Analysis of Mechanical Systems (ADAMS), a Commercial off the Shelf (COTS) tool, was employed to provide insight into the multi-body six degree of freedom (DOF) interaction between parachute test hardware and external and internal forces. Components of the model include a composite extraction parachute, primary vehicle (PTV or PCDTV), platform cradle, a release mechanism, aircraft ramp, and a programmer parachute with attach points. Independent aerodynamic forces were applied to the mated test vehicle/platform cradle and the separated test vehicle and platform cradle. The aero coefficients were determined from real time lookup tables which were functions of both angle of attack ( ) and sideslip ( ). The atmospheric properties were also determined from a real time lookup table characteristic of the Yuma Proving Grounds (YPG) atmosphere relative to the planned test month. Representative geometries were constructed in ADAMS with measured mass properties generated for each independent vehicle. Derived smart separation parameters were included in ADAMS as sensors with defined pitch and pitch rate criteria used to refine inputs to analogous avionics systems for optimal separation conditions. Key design variables were dispersed in a Monte Carlo analysis to provide the maximum expected range of the state variables at programmer deployment to be used as ICs in DSS. Extensive comparisons were made with Decelerator System Simulation Application (DSSA) to validate the mated portion of the ADAMS extraction trajectory. Results of the comparisons improved the fidelity of ADAMS with a ramp pitch profile update from DSSA. Post-test reconstructions resulted in improvements to extraction parachute drag area knock-down factors, extraction line modeling, and the inclusion of ball-to-socket attachments used as a release mechanism on the PTV. Modeling of two Extraction parachutes was based on United States Air Force (USAF) tow test data and integrated into ADAMS for nominal and Monte Carlo trajectory assessments. Video overlay of ADAMS animations and actual C-12 chase plane test videos supported analysis and observation efforts of extraction and separation events. The COTS ADAMS simulation has been integrated with NASA based simulations to provide complete end to end trajectories with a focus on the extraction, separation, and programmer deployment sequence. The flexibility of modifying ADAMS inputs has proven useful for sensitivity studies and extraction/separation modeling efforts. 1

Development of a regional ocean color algorithm using field- and satellite-derived datasets: Long Bay, South Carolina

NASA Astrophysics Data System (ADS)

Ryan, Kimberly Susan

Coastal and inland waters represent a diverse set of resources that support natural habitat and provide numerous ecosystem services to the human population. Conventional techniques to monitor water quality using in situ sensors and laboratory analysis of water samples can be very time- and cost-intensive. Alternatively, remote sensing techniques offer better spatial coverage and temporal resolution to accurately characterize the dynamic and unique water quality parameters. However, bio and geo-optical models are required that relate the remotely sensed spectral data with color producing agents (CPAs) that define the water quality. These CPAs include chlorophyll-a, suspended sediments, and colored-dissolved organic matter. Developing these models may be challenging for coastal environments such as Long Bay, South Carolina, due to the presence of multiple optically interfering CPAs. In this work, a regionally tiered ocean color model was developed using band ratio techniques to specifically predict the variability of chlorophyll-a concentrations in the turbid Long Bay waters. This model produced higher accuracy results (r-squared = 0.62; RMSE = 0.87 micrograms per liter) compared to the existing models, which gave a highest r-squared value of 0.58 and RMSE = 0.99 micrograms per liter. To further enhance the retrievals of chlorophyll-a in these optically complex waters, a novel multivariate-based approach was developed using current generation hyperspectral data. This approach uses a partial least-squares regression model to identify wavelengths that are more sensitive to chlorophyll-a relative to other associated CPAs. This model was able to explain 80% of the observed chlorophyll-a variability in Long Bay with RMSE = 2.03 micrograms per liter. This approach capitalizes on the spectral advantage gained from hyperspectral sensors, thus providing a more robust predicting model. This enhanced mode of water quality monitoring in marine environments will provide insight to point-sources and problem areas that may contribute to a decline in water quality. Moreover, remote sensing applications such as this can be used as a tool for coastal and fisheries managers with regard to recreation, regulation, economic and public health purposes.

7 CFR 1773.1 - General.

Code of Federal Regulations, 2012 CFR

2012-01-01

... accountant (CPA), satisfactory to RUS, and accompanied by a report of such audit, in form and substance... instrument by setting forth the criteria for CPAs to be deemed satisfactory to RUS and the audit procedures...

7 CFR 1773.1 - General.

Code of Federal Regulations, 2013 CFR

2013-01-01

... accountant (CPA), satisfactory to RUS, and accompanied by a report of such audit, in form and substance... instrument by setting forth the criteria for CPAs to be deemed satisfactory to RUS and the audit procedures...

7 CFR 1773.1 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... accountant (CPA), satisfactory to RUS, and accompanied by a report of such audit, in form and substance... instrument by setting forth the criteria for CPAs to be deemed satisfactory to RUS and the audit procedures...

7 CFR 1773.1 - General.

Code of Federal Regulations, 2014 CFR

2014-01-01

... accountant (CPA), satisfactory to RUS, and accompanied by a report of such audit, in form and substance... instrument by setting forth the criteria for CPAs to be deemed satisfactory to RUS and the audit procedures...

7 CFR 1773.1 - General.

Code of Federal Regulations, 2011 CFR

2011-01-01

... accountant (CPA), satisfactory to RUS, and accompanied by a report of such audit, in form and substance... instrument by setting forth the criteria for CPAs to be deemed satisfactory to RUS and the audit procedures...

A community-based partnership collaborative practice agreement project to teach innovation in care delivery.

PubMed

Hohmeier, Kenneth C; Spivey, Christina A; Chisholm-Burns, Marie

2017-05-01

To explore students' perceptions (self-assessment) of their preparedness to develop collaborative practice agreements (CPAs) before and after delivery of one CPA-focused classroom lectures and 2) a CPA development student project in partnership with a local community-based pharmacy. A CPA-focused didactic lecture and subsequent project were given to second-year (P2) pharmacy students enrolled in a community pharmacy elective course at the University of Tennessee College of Pharmacy. Pre- and post-surveys were administered using an online survey platform to assess student perceptions. Responses for each survey question were summarized using frequencies, and chi-square analysis was conducted to assess the association between pre- and post-scores on each question. Students were significantly more likely to rate themselves as prepared or completely prepared to develop a CPA in a community pharmacy setting (χ 2 =61.21, p<0.01) after the course and project. Students also noted that they felt they were prepared or very prepared to work within a team to develop and implement a CPA in a community pharmacy setting (χ 2 =37.60, p<0.01). This study demonstrated that a didactic classroom lecture series followed by a student project partnered with a local community pharmacy improved perceived knowledge, preparedness, and ability to implement CPAs in a community pharmacy. Through intentional exposure of students to scope-of-practice expanding opportunities like CPAs, pharmacy educators can potentially accelerate the evolution of community pharmacy practice. Copyright © 2017 Elsevier Inc. All rights reserved.

78 FR 69451 - Information Collection; Request for Public Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-19

... governments (including State auditors), the American Institute of Certified Public Accountants, certified public accountants (CPAs), Federal agencies and a grantee. The comments received relating to the... OFFICE OF MANAGEMENT AND BUDGET Information Collection; Request for Public Comments AGENCY: Office...

The dopamine antagonist cis-flupenthixol blocks the expression of the conditioned positive but not the negative effects of cocaine in rats

PubMed Central

Wenzel, Jennifer M.; Su, Zu-In; Shelton, Kerisa; Dominguez, Hiram M.; von Furstenberg, Victoria A.; Ettenberg, Aaron

2013-01-01

Human cocaine users report that the initial “high” produced by cocaine administration is followed by an anxiogenic “crash”. Given that cocaine has such robust and opposing properties, it is likely that both the positive and negative effects of cocaine contribute to an individual’s motivation to administer the drug. Despite this likelihood, the neurobiology underlying cocaine’s dual processes remains unclear. While much literature supports a role for dopamine (DA) in cocaine reward, it is uncertain if DA also contributes to the drug’s negative effects. Our laboratory has extensively utilized a modified conditioned place test to explore cocaine’s opponent processes. In this paradigm rats develop conditioned place preferences (CPPs) for an environment paired with the immediate/positive effects of cocaine, and conditioned place aversions (CPAs) for an environment paired with the delayed/negative effects present 15-min after i.v. injection. In the current study rats were conditioned to associate an environment with either the immediate or delayed effects of i.v. cocaine (1 mg/kg/0.1 ml) three hours after i.p. pre-treatment with either the DA D1/D2 receptor antagonist cis-flupenthixol (0.5 mg/kg/ml) or saline vehicle. As expected, vehicle-treated control animals developed the normal pattern of CPPs for cocaine’s immediate effects or CPAs for the delayed effects of cocaine. However, while DA receptor antagonism prevented the expression of cocaine CPPs it did not alter the expression of cocaine-induced CPAs. These data confirm a role for DA transmission in cocaine reward but suggest that different neural pathways mediate the drug’s negative/anxiogenic properties. PMID:24012795

Compensatory Postural Adjustments in an Oculus Virtual Reality Environment and the Risk of Falling in Alzheimer's Disease.

PubMed

Gago, Miguel F; Yelshyna, Darya; Bicho, Estela; Silva, Hélder David; Rocha, Luís; Lurdes Rodrigues, Maria; Sousa, Nuno

2016-01-01

Alzheimer's disease (AD) patients have an impaired ability to quickly reweight central sensory dependence in response to unexpected body perturbations. Herein, we aim to study provoked compensatory postural adjustments (CPAs) in a conflicting sensory paradigm with unpredictable visual displacements using virtual reality goggles. We used kinematic time-frequency analyses of two frequency bands: a low-frequency band (LB; 0.3-1.5 Hz; mechanical strategy) and a high-frequency band (HB; 1.5-3.5 Hz; cognitive strategy). We enrolled 19 healthy subjects (controls) and 21 AD patients, divided according to their previous history of falls. The AD faller group presented higher-power LB CPAs, reflecting their worse inherent postural stability. The AD patients had a time lag in their HB CPA reaction. The slower reaction by CPA in AD may be a reflection of different cognitive resources including body schema self-perception, visual motion, depth perception, or a different state of fear and/or anxiety.

Improved low-CPA vitrification of mouse oocytes using quartz microcapillary.

PubMed

Choi, Jung Kyu; Huang, Haishui; He, Xiaoming

2015-06-01

Cryopreservation by low-cryoprotectant (CPA) vitrification has the potential to combine all the advantages of the conventional high-CPA vitrification and slow-freezing approaches while avoiding their drawbacks. However, current low-CPA vitrification protocol for cryopreservation of oocytes requires a lengthy and multi-step procedure for unloading CPAs. In this study, we report a much-simplified procedure of using quartz microcapillary (QMC) for low-CPA vitrification of mouse oocytes with only one step for unloading CPAs. The immediate viability of oocytes after the improved low-CPA vitrification was determined to be more than 90%. Moreover, no significant difference was observed in terms of embryonic development from the two-cell to blastocyst stages between the fresh and vitrified oocytes after in vitro fertilization (IVF). This improved low-CPA vitrification technology has the potential for efficient cryopreservation of oocytes to preserve the fertility of mammals including humans for assisted reproductive medicine, maintenance of animal resource and endangered species, and livestock management. Copyright © 2015 Elsevier Inc. All rights reserved.

Compensatory Postural Adjustments in an Oculus Virtual Reality Environment and the Risk of Falling in Alzheimer's Disease

PubMed Central

Gago, Miguel F.; Yelshyna, Darya; Bicho, Estela; Silva, Hélder David; Rocha, Luís; Lurdes Rodrigues, Maria; Sousa, Nuno

2016-01-01

Background/Aims Alzheimer's disease (AD) patients have an impaired ability to quickly reweight central sensory dependence in response to unexpected body perturbations. Herein, we aim to study provoked compensatory postural adjustments (CPAs) in a conflicting sensory paradigm with unpredictable visual displacements using virtual reality goggles. Methods We used kinematic time-frequency analyses of two frequency bands: a low-frequency band (LB; 0.3-1.5 Hz; mechanical strategy) and a high-frequency band (HB; 1.5-3.5 Hz; cognitive strategy). We enrolled 19 healthy subjects (controls) and 21 AD patients, divided according to their previous history of falls. Results The AD faller group presented higher-power LB CPAs, reflecting their worse inherent postural stability. The AD patients had a time lag in their HB CPA reaction. Conclusion The slower reaction by CPA in AD may be a reflection of different cognitive resources including body schema self-perception, visual motion, depth perception, or a different state of fear and/or anxiety. PMID:27489559

2012 Ground Testing Highlights

NASA Technical Reports Server (NTRS)

Buchholz, Steven J.

2012-01-01

As part of the Fundamental Aeronautics Program and a collaborative effort with Boeing, and Lockheed Martin this past year a series of sonic boom test were completed in the NASA Ames Unitary Plan Wind Tunnel (UPWT). One of the goals was to develop new test techniques and hardware for measuring sonic boom signatures in the transonic and supersonic regimes. Data for various model designs and configurations were collected and will be used to validate CFD predictions of sonic boom signatures. Reactivation of the NASA Ames Mitsubishi compressor system was completed this past year. The compressor is intended to replace and augment the existing UPWT Clark Compressor as the primary Make Up Air (MUA) source. The MUA system provides air and vacuum pumping capability to the Ames UPWT. It will improve productivity and reliability of the UPWT as a vital testing and research facility for the U.S. aerospace industry and NASA. Funding for this task was provided from the American Recovery Investment Act (ARRA). Installation and validation of a Noncontact Stress Monitoring System (NSMS) for the 3-stage compressor was completed at the 11-foot Transonic Wind Tunnel. The system, originally developed at AEDC, consists of 36 pairs of LED light sources with optic beam send and receive probes along a 1-per rev signal. The new system allows for continuous monitoring and recording of compressor blade bending and torsion stress during normal test operations. A very unusual test was completed in the 11 FT TWT to acquire aerodynamic and flow field data for the Crew Exploration Vehicle (CEV) Parachute Assembly System (CPAS) to validate CFD methods and tools. Surface pressure distribution measurements and velocity measurements in the wake of the command module back to the drogues parachute location were acquired. Testing methods included Particle Image Velocimetry (PIV), Pressure Sensitive Paint (PSP), Schlieren Infrared Imaging (IR) and boundary layer survey and skin friction.

Generation Next

ERIC Educational Resources Information Center

Hawkins, B. Denise

2010-01-01

There is a shortage of accounting professors with Ph.D.s who can prepare the next generation. To help reverse the faculty deficit, the American Institute of Certified Public Accountants (CPAs) has created the new Accounting Doctoral Scholars program by pooling more than $17 million and soliciting commitments from more than 70 of the nation's…

Mandatory Continuing Professional Education for CPAs: Is It Working?

ERIC Educational Resources Information Center

Coffee, David; Beegle, John

1994-01-01

According to responses from 254 of 400 certified public accountants (133 practitioners, 121 educators), 91% believe that mandatory continuing professional education is beneficial and enhances professional image. Most believe it improves the quality of their work; practitioners feel more strongly about the benefits than do educators. (SK)

7 CFR 1773.4 - Borrower responsibilities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... responsibilities. (a) Selection of a qualified CPA. The borrower's board of directors is responsible for the selection of a qualified CPA that meets the requirements set forth in § 1773.5. When selecting a CPA, the borrower should consider, among other matters: (1) The qualifications of CPAs available to do the work; (2...

7 CFR 1773.4 - Borrower responsibilities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... responsibilities. (a) Selection of a qualified CPA. The borrower's board of directors is responsible for the selection of a qualified CPA that meets the requirements set forth in § 1773.5. When selecting a CPA, the borrower should consider, among other matters: (1) The qualifications of CPAs available to do the work; (2...

46 CFR 232.6 - Financial report filing requirement.

Code of Federal Regulations, 2012 CFR

2012-10-01

... certified public accountants (CPAs) licensed to practice by a state or other political subdivision of the... accounting period. If certified (CPA) statements are not available when required, company certified statements are to be submitted within the due dates, and the CPA statements shall be submitted as soon as...

46 CFR 232.6 - Financial report filing requirement.

Code of Federal Regulations, 2014 CFR

2014-10-01

... certified public accountants (CPAs) licensed to practice by a state or other political subdivision of the... accounting period. If certified (CPA) statements are not available when required, company certified statements are to be submitted within the due dates, and the CPA statements shall be submitted as soon as...

7 CFR 1773.4 - Borrower responsibilities.

Code of Federal Regulations, 2014 CFR

2014-01-01

... responsibilities. (a) Selection of a qualified CPA. The borrower's board of directors is responsible for the selection of a qualified CPA that meets the requirements set forth in § 1773.5. When selecting a CPA, the borrower should consider, among other matters: (1) The qualifications of CPAs available to do the work; (2...

46 CFR 232.6 - Financial report filing requirement.

Code of Federal Regulations, 2011 CFR

2011-10-01

... certified public accountants (CPAs) licensed to practice by a state or other political subdivision of the... accounting period. If certified (CPA) statements are not available when required, company certified statements are to be submitted within the due dates, and the CPA statements shall be submitted as soon as...

46 CFR 232.6 - Financial report filing requirement.

Code of Federal Regulations, 2013 CFR

2013-10-01

... certified public accountants (CPAs) licensed to practice by a state or other political subdivision of the... accounting period. If certified (CPA) statements are not available when required, company certified statements are to be submitted within the due dates, and the CPA statements shall be submitted as soon as...

7 CFR 1773.4 - Borrower responsibilities.

Code of Federal Regulations, 2012 CFR

2012-01-01

... responsibilities. (a) Selection of a qualified CPA. The borrower's board of directors is responsible for the selection of a qualified CPA that meets the requirements set forth in § 1773.5. When selecting a CPA, the borrower should consider, among other matters: (1) The qualifications of CPAs available to do the work; (2...

7 CFR 1773.4 - Borrower responsibilities.

Code of Federal Regulations, 2013 CFR

2013-01-01

... responsibilities. (a) Selection of a qualified CPA. The borrower's board of directors is responsible for the selection of a qualified CPA that meets the requirements set forth in § 1773.5. When selecting a CPA, the borrower should consider, among other matters: (1) The qualifications of CPAs available to do the work; (2...

Attitudes of Students and Practitioners Regarding Ethical Acceptability of Accounting Transactions

ERIC Educational Resources Information Center

Fischer, Mary; Marsh, Treba; Hunt, George L.

2013-01-01

This study reports the findings of a study assessing the acceptability differences in decisions made by Certified Public Accounting practitioners (CPA) and students studying to become CPAs. The study responds to researchers' call for additional research on topics related to accounting decision ethics. Modified managerial and accounting recognition…

CPA Perceptions of Human Skills for Professional Competency Development Needs

ERIC Educational Resources Information Center

Day, Kari C.

2017-01-01

This study addressed CPA perceptions about the need for human skill competencies as professional development. The problem was identified as the undetermined assessment of state level CPA perceptions about human skill competencies as developmental needs. CPAs and education providers may be impacted by this problem. The purpose of this study was to…

Written Language Skills of Entry-Level Accountants as Assessed by Experienced CPAs.

ERIC Educational Resources Information Center

Nelson, Sandra J.; Moncada, Susan; Smith, Douglas C.

1996-01-01

Surveys experienced Certified Public Accountants to examine their perceptions of the written language skills of entry-level accountants. Finds that written language fundamentals in word selection and usage, sentence and paragraph construction, and grammar and mechanics remain a problem for entry-level accountants. Notes the value of these findings…

The Impact of the Sarbanes-Oxley Act of 2002 on the Business and Accounting Curriculums

ERIC Educational Resources Information Center

Reed, Ronald O.; Bullock, Charles; Johnson, Gene; Iyer, Vish

2007-01-01

Business and accounting curriculums are designed to educate and train future business professionals and leaders. When Congress passed SOX in 2002, it dramatically impacted the responsibilities of corporate executives and CPAs and consequently required corresponding changes in the business schools prepare students to assume these roles. Because the…

Amerindian-specific regions under positive selection harbour new lipid variants in Latinos

PubMed Central

Ko, Arthur; Cantor, Rita M.; Weissglas-Volkov, Daphna; Nikkola, Elina; Reddy, Prasad M. V. Linga; Sinsheimer, Janet S.; Pasaniuc, Bogdan; Brown, Robert; Alvarez, Marcus; Rodriguez, Alejandra; Rodriguez-Guillen, Rosario; Bautista, Ivette C.; Arellano-Campos, Olimpia; Muñoz-Hernández, Linda L.; Salomaa, Veikko; Kaprio, Jaakko; Jula, Antti; Jauhiainen, Matti; Heliövaara, Markku; Raitakari, Olli; Lehtimäki, Terho; Eriksson, Johan G.; Perola, Markus; Lohmueller, Kirk E.; Matikainen, Niina; Taskinen, Marja-Riitta; Rodriguez-Torres, Maribel; Riba, Laura; Tusie-Luna, Teresa; Aguilar-Salinas, Carlos A.; Pajukanta, Päivi

2014-01-01

Dyslipidemia and obesity are especially prevalent in populations with Amerindian backgrounds, such as Mexican–Americans, which predispose these populations to cardiovascular disease. Here we design an approach, known as the cross-population allele screen (CPAS), which we conduct prior to a genome-wide association study (GWAS) in 19,273 Europeans and Mexicans, in order to identify Amerindian risk genes in Mexicans. Utilizing CPAS to restrict the GWAS input variants to only those differing in frequency between the two populations, we identify novel Amerindian lipid genes, receptor-related orphan receptor alpha (RORA) and salt-inducible kinase 3 (SIK3), and three loci previously unassociated with dyslipidemia or obesity. We also detect lipoprotein lipase (LPL) and apolipoprotein A5 (APOA5) harbouring specific Amerindian signatures of risk variants and haplotypes. Notably, we observe that SIK3 and one novel lipid locus underwent positive selection in Mexicans. Furthermore, after a high-fat meal, the SIK3 risk variant carriers display high triglyceride levels. These findings suggest that Amerindian-specific genetic architecture leads to a higher incidence of dyslipidemia and obesity in modern Mexicans. PMID:24886709

Cryopreservation of stallion spermatozoa using different cryoprotectants and combinations of cryoprotectants.

PubMed

Wu, Zhuangyuan; Zheng, Xinbiao; Luo, Yongming; Huo, Fei; Dong, Hong; Zhang, Guoting; Yu, Weihao; Tian, Fang; He, Liangjun; Chen, Jingbo

2015-12-01

The present study investigates the effects of five cryoprotectants (CPAs) and cryoprotectant combinations on the post-thaw total motility, progressive motility, viability, mitochondrial membrane potential and acrosome integrity in stallion spermatozoa. In Experiment 1, the objective was to compare the impact of different concentrations (2.5%, 3.5% and 5%) of a single CPA, including glycerol (Gly), ethylene glycol (EG), dimethyl sulphoxide (DMSO), methyl formamide (MF), and dimethylformamide (DMF) for stallion spermatozoa cryopreservation. In Experiment 2, two or more CPAs were used to assess whether this improved post-thaw spermatozoa quality. Gly, MF and DMF, were used to prepare seven combinations of freezing extender with different mixtures of cryoprotectant, and the 3.5% Gly, MF and DMF were used as a control group. The results show that post-thaw total motility, progressive motility, viability, and mitochondrial membrane potential for all concentrations of EG and DMSO were less than the 3.5% and 5% Gly and MF and 2.5% and 3.5% DMF (P<0.05). Use of the 3.5% concentration resulted in the greater post-thaw total motility and progressive motility than the 2.5% and 5% concentrations for all CPAs. The results for the use of different combinations of cryoprotectant indicate there are differences in progressive motility and viability. The viability with the use of Gly(2/3)+MF(1/3) was 44.65% and was greater than the Gly(1/3)+MF(1/3)+DMF(1/3) (30.96%), MF(2/3)+DMF(1/3) (35.05%), Gly (32.21%) and MF(33.76%) (P<0.05). The progressive motility with the use of the MF(2/3)+Gly(1/3) combination was 36.0% and was greater than in the DMF (25.0%) and MF(2/3)+DMF(1/3) (22.7%) (P<0.05). These results suggest that using the appropriate cryoprotectant combination instead of a single cryoprotectant can improve horse spermatozoa cryopreservation. Copyright © 2015 Elsevier B.V. All rights reserved.

APRON: A Cellular Processor Array Simulation and Hardware Design Tool

NASA Astrophysics Data System (ADS)

Barr, David R. W.; Dudek, Piotr

2009-12-01

We present a software environment for the efficient simulation of cellular processor arrays (CPAs). This software (APRON) is used to explore algorithms that are designed for massively parallel fine-grained processor arrays, topographic multilayer neural networks, vision chips with SIMD processor arrays, and related architectures. The software uses a highly optimised core combined with a flexible compiler to provide the user with tools for the design of new processor array hardware architectures and the emulation of existing devices. We present performance benchmarks for the software processor array implemented on standard commodity microprocessors. APRON can be configured to use additional processing hardware if necessary and can be used as a complete graphical user interface and development environment for new or existing CPA systems, allowing more users to develop algorithms for CPA systems.

CPAs in Mississippi: Communication Skills and Software Needed by Entry-Level Accountants

ERIC Educational Resources Information Center

Bunn, Phyllis C.; Barfit, Laurie A.; Cooper, Jan

2005-01-01

The purpose of this paper was to determine what communication skills are considered most important by employers in the accounting profession as well as to determine the general office, income tax, and bookkeeping software packages used by CPA firms in Mississippi. The data was collected by means of an electronic five-point Likert-type survey…

Comparing Students in Each California Partnership Academy with Non-Academy Students at the Same High School, 2009-10

ERIC Educational Resources Information Center

Stern, David; Saroyan, Phil; Hamilton Hester, Candace

2012-01-01

This report is a sequel to "Profile of the California Partnership Academies, 2009-2010." The "Profile" gave an overview of California Partnerships Academies (CPAs), and included some comparisons between CPA students and all high school students in California. This report provides, for the first time, comparisons between…

A Hybrid Parachute Simulation Environment for the Orion Parachute Development Project

NASA Technical Reports Server (NTRS)

Moore, James W.

2011-01-01

A parachute simulation environment (PSE) has been developed that aims to take advantage of legacy parachute simulation codes and modern object-oriented programming techniques. This hybrid simulation environment provides the parachute analyst with a natural and intuitive way to construct simulation tasks while preserving the pedigree and authority of established parachute simulations. NASA currently employs four simulation tools for developing and analyzing air-drop tests performed by the CEV Parachute Assembly System (CPAS) Project. These tools were developed at different times, in different languages, and with different capabilities in mind. As a result, each tool has a distinct interface and set of inputs and outputs. However, regardless of the simulation code that is most appropriate for the type of test, engineers typically perform similar tasks for each drop test such as prediction of loads, assessment of altitude, and sequencing of disreefs or cut-aways. An object-oriented approach to simulation configuration allows the analyst to choose models of real physical test articles (parachutes, vehicles, etc.) and sequence them to achieve the desired test conditions. Once configured, these objects are translated into traditional input lists and processed by the legacy simulation codes. This approach minimizes the number of sim inputs that the engineer must track while configuring an input file. An object oriented approach to simulation output allows a common set of post-processing functions to perform routine tasks such as plotting and timeline generation with minimal sensitivity to the simulation that generated the data. Flight test data may also be translated into the common output class to simplify test reconstruction and analysis.

Nonuniversal Z' couplings in B decays

NASA Astrophysics Data System (ADS)

Chen, Chuan-Hung; Hatanaka, Hisaki

2006-04-01

We study the impacts of the nonuniversal Z' model, providing flavor-changing neutral current at tree level, on the branching ratios (BRs), CP asymmetries (CPAs), and polarization fractions of B decays. We find that, for satisfying the current data, the new left- and right-handed couplings have to be included at the same time. The new introduced effective interactions not only could effectively explain the puzzle of small longitudinal polarization in B→K*ϕ decays, but also provide a solution to the small CPA of B±→π0K±. We also find that the favorable CPA of B±→π0K± is opposite in sign to the standard model; meanwhile, the CPA of Bd→π0K has to be smaller than -10%. In addition, by using the values of parameters which are constrained by B→πK, we find that the favorable ranges of BRs, CPAs, longitudinal polarizations, and perpendicular transverse polarizations for (B±→ρ±K*,Bd→ρ∓K*±) are (17.1±3.9,10.0±2.0)×10-6, (3±5,21±7)%, (0.66±0.10,0.44±0.08), and (0.14±0.10,0.25±0.09), respectively.

Orion MPCV Touchdown Detection Threshold Development and Testing

NASA Technical Reports Server (NTRS)

Daum, Jared; Gay, Robert

2013-01-01

A robust method of detecting Orion Multi-Purpose Crew Vehicle (MPCV) splashdown is necessary to ensure crew and hardware safety during descent and after touchdown. The proposed method uses a triple redundant system to inhibit Reaction Control System (RCS) thruster firings, detach parachute risers from the vehicle, and transition to the post-landing segment of the Flight Software (FSW). An in-depth trade study was completed to determine optimal characteristics of the touchdown detection method resulting in an algorithm monitoring filtered, lever-arm corrected, 200 Hz Inertial Measurement Unit (IMU) vehicle acceleration magnitude data against a tunable threshold using persistence counter logic. Following the design of the algorithm, high fidelity environment and vehicle simulations, coupled with the actual vehicle FSW, were used to tune the acceleration threshold and persistence counter value to result in adequate performance in detecting touchdown and sufficient safety margin against early detection while descending under parachutes. An analytical approach including Kriging and adaptive sampling allowed for a sufficient number of finite element analysis (FEA) impact simulations to be completed using minimal computation time. The combination of a persistence counter of 10 and an acceleration threshold of approximately 57.3 ft/s2 resulted in an impact performance factor of safety (FOS) of 1.0 and a safety FOS of approximately 2.6 for touchdown declaration. An RCS termination acceleration threshold of approximately 53.1 ft/s(exp)2 with a persistence counter of 10 resulted in an increased impact performance FOS of 1.2 at the expense of a lowered under-parachutes safety factor of 2.2. The resulting tuned algorithm was then tested on data from eight Capsule Parachute Assembly System (CPAS) flight tests, showing an experimental minimum safety FOS of 6.1. The formulated touchdown detection algorithm will be flown on the Orion MPCV FSW during the Exploration Flight Test 1 (EFT-1) mission in the second half of 2014.

Cryopreservation of rabbit semen: comparing the effects of different cryoprotectants, cryoprotectant-free vitrification, and the use of albumin plus osmoprotectants on sperm survival and fertility after standard vapor freezing and vitrification.

PubMed

Rosato, Maria Pina; Iaffaldano, Nicolaia

2013-02-01

This study was designed to improve current freezing protocols for rabbit sperm by examining: (1) the toxicity of different permeable cryoprotectants (CPAs) used for standard vapor freezing (conventional freezing); (2) the feasibility of ultrarapid nonequilibrium freezing (vitrification) of sperm in the absence of permeating CPAs; and (3), the addition of bovine serum albumin (BSA), alone or with sucrose or trehalose as osmoprotectants. First, we evaluated the effects on sperm motility of the incubation time (5 to 60 minutes) with different final concentrations (5% to 20%) of glycerol, N-N-dimethylacetamide, dimethylsulfoxide (DMSO), ethylene glycol, propylene glycol, and methanol. N-N-dimethylacetamide (5%) and DMSO (5% and 10%) showed the least toxic effects; the use of 10% DMSO producing the best postthaw sperm motility and membrane integrity results (P < 0.05) after conventional freezing. For vitrification, semen was diluted in the absence of permeable CPAs and frozen by dropping semen directly in liquid nitrogen. However, this led to the low or null cryosurvival of sperm postvitrification (0.16 ± 0.4%, 1.8 ± 1.6%, and 94.5 ± 1.4% of motile, membrane-, and DNA-intact sperm cells, respectively). To assess the effects of albumin and osmoprotectants on sperm cryosurvival, sperm was conventionally frozen with 10% DMSO or vitrified in the absence of permeable CPAs without or with 0.5% BSA alone or combined with sucrose or trehalose (range, 0-0.25 M). In the conventional freezing procedure, the addition of BSA alone failed to improve sperm cryosurvival, however, in the presence of BSA plus either sucrose or trehalose, the postthaw motility (using 0.1 M sucrose or trehalose) and DNA integrity (using all additive concentrations) of sperm were significantly better (P < 0.05) than control. Higher numbers of motile and membrane-intact cells were observed when semen was vitrified with BSA alone or with BSA and sucrose (0.1 and 0.25 M) or BSA and trehalose (0.25 M) and a best recovery of DNA-intact sperm was recorded for BSA plus sucrose compared with semen vitrified without osmoprotectants (P < 0.05). Finally, the cryodiluent combinations BSA/sucrose and BSA/trehalose were compared in an insemination trial. Rabbit does were inseminated with fresh semen (N = 56), semen conventionally cryopreserved in the BSA-based cryodiluents containing 0.1 M sucrose or trehalose (N = 56 per group), or semen vitrified in the presence of 0.25 M sucrose or trehalose (N = 8 per group). Fertility rates and live born kids were similar for semen cryopreserved with BSA/sucrose (77% and 7.6) compared with fresh semen (84% and 8.1) and significantly higher than the figures recorded for the conventionally frozen semen in the BSA/trehalose group (52% and 6.1; P ≤ 0.05). In contrast, only one doe inseminated with semen vitrified in the presence of BSA/sucrose became pregnant, though no kids were delivered. The conclusions to be drawn from our study are: (1) incubation times and concentration toxicities established for the main permeable CPAs used for conventional freezing of rabbit sperm indicated that DMSO 10% was the least damaging; (2) CPA-free vitrification of rabbit semen led to a low or null sperm cryosurvival; and (3) enriching the freezing medium with BSA plus adequate amounts of sucrose or trehalose can improve the cryosurvival of rabbit sperm after conventional freezing or vitrification. In our working conditions, BSA/sucrose was more effective than BSA/trehalose at preserving the in vivo fertilization capacity of rabbit sperm cryopreserved using the standard procedure. Copyright © 2013 Elsevier Inc. All rights reserved.

Changes in Postural Control After a Ball-Kicking Balance Exercise in Individuals With Chronic Ankle Instability

PubMed Central

Conceição, Josilene Souza; Schaefer de Araújo, Felipe Gustavo; Santos, Gilmar Moraes; Keighley, John

2016-01-01

Context:  Rehabilitation programs for patients with chronic ankle instability (CAI) generally involve balance-perturbation training (BPT). Anticipatory postural adjustments (APAs) and compensatory postural adjustments (CPAs) are the primary strategies used to maintain equilibrium during body perturbations. Little is known, however, about how APAs and CPAs are modified to promote better postural control for individuals with CAI after BPT. Objective:  To investigate the effect of BPT that involves kicking a ball on postural-control strategies in individuals with CAI. Design:  Randomized controlled clinical trial. Setting:  Laboratory. Patients or Other Participants:  We randomly assigned 44 volunteers with CAI to either a training group (TG; 11 women, 11 men; age = 24 ± 4 years, height = 173.0 ± 9.8 cm, mass = 72.64 ± 11.98 kg) or control group (CG; 11 women, 11 men; age = 22 ± 3 years, height = 171.0 ± 9.7 cm, mass = 70.00 ± 11.03 kg). Intervention(s):  The TG performed a single 30-minute training session that involved kicking a ball while standing on 1 foot. The CG received no intervention. Main Outcome Measure(s):  The primary outcome was the sum of the integrated electromyographic activity (∑∫EMG) of the lower extremity muscles in the supporting limb that were calculated during typical intervals for APAs and CPAs. A secondary outcome was center-of-pressure displacement during similar intervals. Results:  In the TG after training, the ∑∫EMG decreased in both dorsal and ventral muscles during compensatory adjustment (ie, the time interval that followed lower limb movement). During this interval, muscle activity (∑∫EMG) was less in the TG than in the CG. Consequently, center-of-pressure displacement increased during the task after training. Conclusions:  A single session of ball-kicking BPT promoted changes in postural-control strategies in individuals with CAI. These results should stimulate new and more comprehensive studies to investigate the effect of this and other BPT techniques on postural control in patients with CAI. PMID:27295488

A case study on bio-optical and radiometric quantities in northwest European shelf seas

NASA Astrophysics Data System (ADS)

Garaba, Shungu; Zielinski, Oliver

2013-04-01

Colour of seawater has become an integral tool in understanding surface marine ecosystems and processes. Additionally, operational oceanographic observatories are becoming more prominent these days while at the same time hyperspectral radiometric sensors are becoming increasingly affordable. This has driven a wide spread use of these hyperspectral sensors to measure reflectance above the water surface from stationary and mobile platforms alike. As enormous amounts of data are produced and favourably processed in real-time, effective quality control procedures become more than just supporting tools, but a crucial prerequisite for trustworthy and manageable information. Here, we use bio-geophysical and hyperspectral radiometric measurements from German Bight (GB), North Sea (NS), Inner Seas (ISS), Irish Sea (IS) and Celtic Sea (CS) to identify and establish relationships between colour producing agents (CPAs) and perceived colour of seawater. In order to obtain valid optical measurements, meteorological and sunglint contamination were mitigated using state-of-the-art quality control protocols. The remote sensing reflectance measured is transformed into discrete Forel-Ule numerical indices (FUI), 1 (indigo-blue, oligotrophic) to 21 (cola brown, hyper-eutrophic). We present a novel approach of estimating which of the three main CPAs of seawater control perceived colour of seawater. Our bio-optical models for estimating FUI for measured CPAs; chlorophyll (Chl-a), coloured dissolved organic material (CDOM) and suspended particulate material (SPM) had correlation coefficients, R² (GB = 0.98, NS = 0.23, ISS=0.99, IS=0.63, CS = 0.16). It was also observed that salinity can be estimated from coloured dissolved organic matter with good accuracy, R² (GB = 0.94, NS = 0.44, ISS=0.90, IS=0.85, CS = 0.51). We show that ocean colour products i.e. reflectance and perceived colour of seawater can be used to infer, with good accuracy, environmental parameters e.g. Chl-a, CDOM, SPM, salinity and Secchi depth of the investigated waters providing an effective and affordable tool for operational marine observations. Improved and extensive field investigations are required to further enhance the sensitivity/accuracy of such region specific bio-optical models.

Development of a regional bio-optical model for water quality assessment in the US Virgin Islands

NASA Astrophysics Data System (ADS)

Kerrigan, Kristi Lisa

Previous research in the US Virgin Islands (USVI) has demonstrated that land-based sources of pollution associated with watershed development and climate change are local and global factors causing coral reef degradation. A good indicator that can be used to assess stress on these environments is the water quality. Conventional assessment methods based on in situ measurements are timely and costly. Satellite remote sensing techniques offer better spatial coverage and temporal resolution to accurately characterize the dynamic nature of water quality parameters by applying bio-optical models. Chlorophyll-a, suspended sediments (TSM), and colored-dissolved organic matter are color-producing agents (CPAs) that define the water quality and can be measured remotely. However, the interference of multiple optically active constituents that characterize the water column as well as reflectance from the bottom poses a challenge in shallow coastal environments in USVI. In this study, field and laboratory based data were collected from sites on St. Thomas and St. John to characterize the CPAs and bottom reflectance of substrates. Results indicate that the optical properties of these waters are a function of multiple CPAs with chlorophyll-a values ranging from 0.10 to 2.35 microg/L and TSM values from 8.97 to 15.7 mg/L. These data were combined with in situ hyperspectral radiometric and Landsat OLI satellite data to develop a regionally tiered model that can predict CPA concentrations using traditional band ratio and multivariate approaches. Band ratio models for the hyperspectral dataset (R2 = 0.35; RMSE = 0.10 microg/L) and Landsat OLI dataset (R2 = 0.35; RMSE = 0.12 microg/L) indicated promising accuracy. However, a stronger model was developed using a multivariate, partial least squares regression to identify wavelengths that are more sensitive to chlorophyll-a (R2 = 0.62, RMSE = 0.08 microg/L) and TSM (R2 = 0.55). This approach takes advantage of the full spectrum of hyperspectral data, thus providing a more robust predictive model. Models developed in this study will significantly improve near-real time and long-term water quality monitoring in USVI and will provide insight to factors contributing to coral reef decline.

Application of a functional marker for the effect of cryoprotectant agents on gorgonian coral (Junceella juncea and J. fragilis) sperm sacs.

PubMed

Tsai, S; Kuit, V; Lin, Z G; Lin, C

2014-01-01

The establishment of coral sperm repositories which retain good post-rewarming viability and fertility play a vital role in species conservation. This study aimed at obtaining baseline information regarding the effects of cryoprotectant agents (CPAs) on gorgonian coral (Junceella juncea and J. fragilis) sperm sacs. The adenosine triphosphate assay was used to determine the energy level of the gorgonian sperm sacs as an indicator of sperm viability after exposure to cryoprotectants. The 'no observed effect concentrations' (NOECs) of methanol, dimethyl sulfoxide (DMSO), polypropylene glycol (PG), ethylene glycol (EG) and glycerol for J. juncea sperm sacs were 3 M, 3 M, 1 M, 2 M and 1 M respectively after 20 min exposure; whilst the NOECs for J. fragilis oocytes were 2 M, 3 M, 1 M, 2 M and 2 M, respectively. Methanol and DMSO had the least impact. PG was the most toxic CPA after 10 min exposure. ATP content of J. juncea and J. fragilis sperm sacs did not differ significantly from the control with incubation times of 10-20 min with 2 M EG. However, ATP content dropped significantly after exposing sperm sacs to 2 M EG for 40 min with average values of 2.34 +/- 0.12 and 1.97 +/- 0.48 microg/ml respectively. ATP content for J. juncea and J. fragilis sperm sacs was significantly decreased to 1.79 +/- 0.31 and 2.40 +/- 0.36 microg/ml after 20 min incubation in 2 M PG when compared to the control with 2.98 +/- 0.16 and 4.14 +/- 0.42 microg/ml respectively. Normalized ATP content for sperm sacs of two different gorgonian coral after incubation in methanol, DMSO, PG, EG and glycerol showed that J. juncea sperm sacs were slightly less tolerant to CPAs compared to J. fragilis sperm sacs. DMSO or methanol can be considered as efficient CPAs for gorgonian sperm sacs cryopreservation. The ATP luminescence assay provided sensitive and rapid quantification of mitochondrial activity in gorgonian coral sperm sacs. The study on the impact of CPA will contribute to the development of a cryopreservation protocol for coral sperm conservation.

The effect of aging on anticipatory postural control

PubMed Central

Kanekar, Neeta; Aruin, Alexander S.

2014-01-01

The aim of the study was to investigate the differences in anticipatory (APAs) postural adjustments between young and older adults and its effect on subsequent control of posture. Ten healthy older adults and thirteen healthy young adults were exposed to predictable external perturbations using the pendulum-impact paradigm. EMG activity of the trunk and leg muscles, the center of pressure (COP), and center of mass (COM) displacements in the anterior-posterior (AP) direction were recorded and analyzed during the anticipatory and compensatory (CPAs) phases of postural control. The effect of aging was seen as delayed anticipatory muscle activity and larger compensatory muscle responses in older adults as compared to young adults. Moreover, in spite of such larger reactive responses, older adults were still more unstable, exhibiting larger COP and COM peak displacements after the perturbation than young adults when exposed to similar postural disturbances. Nonetheless, while APAs are impaired in older adults, the ability to recruit muscles anticipatorily is largely preserved, however, due to their smaller magnitudes and delayed onsets, it is likely that their effectiveness in reducing the magnitude of CPAs is smaller. The outcome of the study lends support towards investigating the ways of improving anticipatory postural control in people with balance impairments due to aging or neurological disorders. PMID:24449006

Prevention of Osmotic Injury to Human Umbilical Vein Endothelial Cells for Biopreservation: A First Step Toward Biobanking of Endothelial Cells for Vascular Tissue Engineering.

PubMed

Niu, Dan; Zhao, Gang; Liu, Xiaoli; Zhou, Ping; Cao, Yunxia

2016-03-01

High-survival-rate cryopreservation of endothelial cells plays a critical role in vascular tissue engineering, while optimization of osmotic injuries is the first step toward successful cryopreservation. We designed a low-cost, easy-to-use, microfluidics-based microperfusion chamber to investigate the osmotic responses of human umbilical vein endothelial cells (HUVECs) at different temperatures, and then optimized the protocols for using cryoprotective agents (CPAs) to minimize osmotic injuries and improve processes before freezing and after thawing. The fundamental cryobiological parameters were measured using the microperfusion chamber, and then, the optimized protocols using these parameters were confirmed by survival evaluation and cell proliferation experiments. It was revealed for the first time that HUVECs have an unusually small permeability coefficient for Me2SO. Even at the concentrations well established for slow freezing of cells (1.5 M), one-step removal of CPAs for HUVECs might result in inevitable osmotic injuries, indicating that multiple-step removal is essential. Further experiments revealed that multistep removal of 1.5 M Me2SO at 25°C was the best protocol investigated, in good agreement with theory. These results should prove invaluable for optimization of cryopreservation protocols of HUVECs.

Control of vertical posture while elevating one foot to avoid a real or virtual obstacle.

PubMed

Ida, Hirofumi; Mohapatra, Sambit; Aruin, Alexander

2017-06-01

The purpose of this study is to investigate the control of vertical posture during obstacle avoidance in a real versus a virtual reality (VR) environment. Ten healthy participants stood upright and lifted one leg to avoid colliding with a real obstacle sliding on the floor toward a participant and with its virtual image. Virtual obstacles were delivered by a head mounted display (HMD) or a 3D projector. The acceleration of the foot, center of pressure, and electrical activity of the leg and trunk muscles were measured and analyzed during the time intervals typical for early postural adjustments (EPAs), anticipatory postural adjustments (APAs), and compensatory postural adjustments (CPAs). The results showed that the peak acceleration of foot elevation in the HMD condition decreased significantly when compared with that of the real and 3D projector conditions. Reduced activity of the leg and trunk muscles was seen when dealing with virtual obstacles (HMD and 3D projector) as compared with that seen when dealing with real obstacles. These effects were more pronounced during APAs and CPAs. The onsets of muscle activities in the supporting limb were seen during EPAs and APAs. The observed modulation of muscle activity and altered patterns of movement seen while avoiding a virtual obstacle should be considered when designing virtual rehabilitation protocols.

Alginate Hydrogel Microencapsulation Inhibits Devitrification and Enables Large-Volume Low-CPA Cell Vitrification

PubMed Central

Huang, Haishui; Choi, Jung Kyu; Rao, Wei; Zhao, Shuting; Agarwal, Pranay; Zhao, Gang

2015-01-01

Cryopreservation of stem cells is important to meet their ever-increasing demand by the burgeoning cell-based medicine. The conventional slow freezing for stem cell cryopreservation suffers from inevitable cell injury associated with ice formation and the vitrification (i.e., no visible ice formation) approach is emerging as a new strategy for cell cryopreservation. A major challenge to cell vitrification is intracellular ice formation (IIF, a lethal event to cells) induced by devitrification (i.e., formation of visible ice in previously vitrified solution) during warming the vitrified cells at cryogenic temperature back to super-zero temperatures. Consequently, high and toxic concentrations of penetrating cryoprotectants (i.e., high CPAs, up to ~8 M) and/or limited sample volumes (up to ~2.5 μl) have been used to minimize IIF during vitrification. We reveal that alginate hydrogel microencapsulation can effectively inhibit devitrification during warming. Our data show that if ice formation were minimized during cooling, IIF is negligible in alginate hydrogel-microencapsulated cells during the entire cooling and warming procedure of vitrification. This enables vitrification of pluripotent and multipotent stem cells with up to ~4 times lower concentration of penetrating CPAs (up to 2 M, low CPA) in up to ~100 times larger sample volume (up to ~250 μl, large volume). PMID:26640426

Alginate Hydrogel Microencapsulation Inhibits Devitrification and Enables Large-Volume Low-CPA Cell Vitrification.

PubMed

Huang, Haishui; Choi, Jung Kyu; Rao, Wei; Zhao, Shuting; Agarwal, Pranay; Zhao, Gang; He, Xiaoming

2015-11-25

Cryopreservation of stem cells is important to meet their ever-increasing demand by the burgeoning cell-based medicine. The conventional slow freezing for stem cell cryopreservation suffers from inevitable cell injury associated with ice formation and the vitrification ( i.e. , no visible ice formation) approach is emerging as a new strategy for cell cryopreservation. A major challenge to cell vitrification is intracellular ice formation (IIF, a lethal event to cells) induced by devitrification ( i.e. , formation of visible ice in previously vitrified solution) during warming the vitrified cells at cryogenic temperature back to super-zero temperatures. Consequently, high and toxic concentrations of penetrating cryoprotectants ( i.e. , high CPAs, up to ~8 M) and/or limited sample volumes (up to ~2.5 μl) have been used to minimize IIF during vitrification. We reveal that alginate hydrogel microencapsulation can effectively inhibit devitrification during warming. Our data show that if ice formation were minimized during cooling, IIF is negligible in alginate hydrogel-microencapsulated cells during the entire cooling and warming procedure of vitrification. This enables vitrification of pluripotent and multipotent stem cells with up to ~4 times lower concentration of penetrating CPAs (up to 2 M, low CPA) in up to ~100 times larger sample volume (up to ~250 μl, large volume).

Thermodynamic nonequilibrium phase change behavior and thermal properties of biological solutions for cryobiology applications.

PubMed

Han, Bumsoo; Bischof, John C

2004-04-01

Understanding the phase change behavior of biomaterials during freezing/thawing including their thermal properties at low temperatures is essential to design and improve cryobiology applications such as cryopreservation and cryosurgery. However, knowledge of phase change behavior and thermal properties of various biomaterials is still incomplete, especially at cryogenic temperatures (< or = -40 degrees C). Moreover, in these applications, chemicals are often added to improve their outcome, which can result in significant variation in the phase change behavior and thermal properties from those of the original biomaterials. These chemical additives include cryoprotective agents (CPAs), antifreeze protein (AFP), or cryosurgical adjuvants like sodium chloride (NaCl). In the present study, phase change behavior and thermal properties of saline solutions--either water-NaCl or phosphate buffered saline (PBS)--with various chemical additives were investigated. The chemical additives studied are glycerol and raffinose as CPAs, an AFP (Type III, molecular weight = 6500), and NaCl as a cryosurgical adjuvant. The phase change behavior was investigated using a differential scanning calorimeter (DSC) and a cryomicroscope. The specific and latent heat of these solutions were also measured with the DSC. The saline solutions have two distinct phase changes--water/ice and eutectic phase changes. During freezing, eutectic solidification of both water-NaCl and PBS are significantly supercooled below their thermodynamic equilibrium eutectic temperatures. However, their melting temperatures are close to thermodynamic equilibrium during thawing. These eutectic phase changes disappear when even a small amount (0.1 M glycerol) of CPA was added, but they are still observed after the addition of an AFP. The specific heats of these solutions are close to that of ice at very low temperatures (< or = -100 degrees C) regardless of the additives, but they increase between -100 degrees C and -30 degrees C with the addition of CPAs. The amount of latent heat, which is evaluated with sample weight, generally decreases with the addition of the additives, but can be normalized to approximately 300 J/g based on the weight of water which participates in the phase change. This illustrates that thermal properties, especially latent heat, of a biomaterial should be evaluated based on the understanding of its phase change behavior. The results of the present study are discussed in the context of the implications for cryobiology applications.

Federal Bureau of Prisons clinical pharmacy program improves patient A1C.

PubMed

Bingham, J Tyler; Mallette, Jeff J

2016-01-01

The Federal Bureau of Prisons (BOP) currently has over 13,000 patients with diabetes and has placed an emphasis on preventing and delaying the onset or progression of diabetes-related complications. In an ongoing effort to improve patient outcomes, BOP has implemented a nationwide, dynamic system of pharmacist-delivered patient care services via pharmacist clinicians working under the auspices of a physician-pharmacist collaborative practice agreement (CPA). The BOP Clinical Pharmacy Workgroup targets improved patient outcomes via oversight and support of institution pharmacist clinicians and physicians in establishing and maintaining physician-pharmacist CPAs. A primary emphasis is diabetes and the pharmacist-run clinic clinical outcomes data are presented. Seventy (nearly one-half) of eligible BOP pharmacists at 37 institutions offer pharmacist-delivered patient care services via an approved CPA. In total, BOP has 111 active physician-pharmacist CPAs. Pharmacist-run diabetes clinic outcomes from 5 institutions have been reported to date. A total of 126 patients were enrolled. Patient's hemoglobin A1C, blood pressure, and LDL cholesterol level are measured before (i.e., when accepted in the diabetes clinic) and after pharmacist-delivered care has been provided. The pharmacist-run diabetes clinics reported an average baseline A1C of 10.6% and produced an average outcome decrease in A1C of 2.3% from baseline. Specific pharmacist clinic interventions found to have the greatest impact are: 1) timely medication adjustment when indicated to help patients meet outcome goals; and 2) timely follow-up after a change in therapy is made (often within 1-2 weeks) with continued medication adjustment when indicated until outcome goal is achieved. BOP pharmacists have become respected and trusted clinicians within the team medicine model. As demonstrated by the pharmacist-run diabetes clinic outcomes, pharmacist clinicians are a valued link to the improvement of patient outcomes in BOP. Copyright © 2016. Published by Elsevier Inc.

Improved conception rates in sows inseminated with cryopreserved boar spermatozoa prepared with a more optimal combination of osmolality and glycerol in the freezing extender.

PubMed

Okazaki, Tetsuji; Abe, Shouhachiro; Shimada, Masayuki

2009-04-01

Cryoprotectant agents (CPAs) are added in freezing extenders to prevent intracellular ice crystal formation. However, it has been reported that high dose of CPAs confer toxicity on spermatozoa. Recently, the reduction of intracellular water by a high osmolality solution has also resulted in the suppression of ice crystal formation in spermatozoa, suggesting that the optimal combination of glycerol concentration and freezing extender osmolality could contribute to the development of effective sperm cryopreservation techniques. In this study, we investigated the motility, membrane and acrosomal integrity of frozen-thawed boar spermatozoa treated with freezing extender (NSF) of varying osmolalities (300, 400, 500 mOsm/kg) and final concentrations of glycerol (0.5, 1, 2, 3%). The spermatozoa that were treated at 400 mOsm/kg and 2% glycerol showed significantly higher rates of motility and membrane integrity compared with those in other treatment groups. In addition, the conception and implantation rates of swine artificially inseminated with spermatozoa frozen by the novel freezing extender (conception; 79%, implantation; 57.5%) were significantly higher than those of frozen-thawed spermatozoa treated in the conventional NSF (300 mOsm/kg, 3% glycerol) (conception; 29%, implantation; 33.8%). From these results, we concluded that the novel hyperosmotic (400 mOsm/kg) and low-glycerol (final concentration 2%) freezing extender is beneficial for the cryopreservation of boar spermatozoa.

Chiral phosphoric acid catalysis: from numbers to insights.

PubMed

Maji, Rajat; Mallojjala, Sharath Chandra; Wheeler, Steven E

2018-02-19

Chiral phosphoric acids (CPAs) have emerged as powerful organocatalysts for asymmetric reactions, and applications of computational quantum chemistry have revealed important insights into the activity and selectivity of these catalysts. In this tutorial review, we provide an overview of computational tools at the disposal of computational organic chemists and demonstrate their application to a wide array of CPA catalysed reactions. Predictive models of the stereochemical outcome of these reactions are discussed along with specific examples of representative reactions and an outlook on remaining challenges in this area.

Molecular characteristics of the KCNJ5 mutated aldosterone-producing adenomas.

PubMed

Murakami, Masanori; Yoshimoto, Takanobu; Nakabayashi, Kazuhiko; Nakano, Yujiro; Fukaishi, Takahiro; Tsuchiya, Kyoichiro; Minami, Isao; Bouchi, Ryotaro; Okamura, Kohji; Fujii, Yasuhisa; Hashimoto, Koshi; Hata, Ken-Ichiro; Kihara, Kazunori; Ogawa, Yoshihiro

2017-10-01

The pathophysiology of aldosterone-producing adenomas (APAs) has been investigated via genetic approaches and the pathogenic significance of a series of somatic mutations, including KCNJ5 , has been uncovered. However, how the mutational status of an APA is associated with its molecular characteristics, including its transcriptome and methylome, has not been fully understood. This study was undertaken to explore the molecular characteristics of APAs, specifically focusing on APAs with KCNJ5 mutations as opposed to those without KCNJ5 mutations, by comparing their transcriptome and methylome status. Cortisol-producing adenomas (CPAs) were used as reference. We conducted transcriptome and methylome analyses of 29 APAs with KCNJ5 mutations, 8 APAs without KCNJ5 mutations and 5 CPAs. Genome-wide gene expression and CpG methylation profiles were obtained from RNA and DNA samples extracted from these 42 adrenal tumors. Cluster analysis of the transcriptome and methylome revealed molecular heterogeneity in APAs depending on their mutational status. DNA hypomethylation and gene expression changes in Wnt signaling and inflammatory response pathways were characteristic of APAs with KCNJ5 mutations. Comparisons between transcriptome data from our APAs and that from normal adrenal cortex obtained from the Gene Expression Omnibus suggested similarities between APAs with KCNJ5 mutations and zona glomerulosa. The present study, which is based on transcriptome and methylome analyses, indicates the molecular heterogeneity of APAs depends on their mutational status. Here, we report the unique characteristics of APAs with KCNJ5 mutations. © 2017 Society for Endocrinology.

Prediction of ice content in biological model solutions when frozen under high pressure.

PubMed

Guignon, B; Aparicio, C; Otero, L; Sanz, P D

2009-01-01

High pressure is, at least, as effective as cryoprotective agents (CPAs) and are used for decreasing both homogenous nucleation and freezing temperatures. This fact gives rise to a great variety of possible cryopreservation processes under high pressure. They have not been optimized yet, since they are relatively recent and are mainly based on the pressure-temperature phase diagram of pure water. Very few phase diagrams of biological material are available under pressure. This is owing to the lack of suitable equipment and to the difficulties encountered in carrying out the measurements. Different aqueous solutions of salt and CPAs as biological models are studied in the range of 0 degrees C down to -35 degrees C, 0.1 up to 250 MPa, and 0-20% w/w total solute concentration. The phase transition curves of glycerol and of sodium chloride with either glycerol or sucrose in aqueous solutions are determined in a high hydrostatic pressure vessel. The experimental phase diagrams of binary solutions were well described by a third-degree polynomial equation. It was also shown that Robinson and Stokes' equation at high pressure succeeds in predicting the phase diagrams of both binary and ternary solutions. The solute cryoconcentration and the ice content were calculated as a function of temperature and pressure conditions during the freezing of a binary solution. This information should provide a basis upon which high-pressure cryopreservation processes may be performed and the damages derived from ice formation evaluated. (c) 2009 American Institute of Chemical Engineers Biotechnol.

Internal Control, CPA Recognition and Performance Consequence: Evidence from Chinese Real Estate Enterprises

NASA Astrophysics Data System (ADS)

Zhang, Chuan; Zhang, Lili; Geng, Yi

In recent years, internal control has caught more and more attention over the whole globe. However, whether internal control could improve business efficiency also lacks the empirical supports. Based on a sample size of 146 Chinese real estate enterprises, this study analyses the CPA’s recognition degree on firm’s implementing internal control, and its performance consequence. The evidence suggests that CPAs are able to give exact evaluation on firm’s internal control implement, and the higher the internal control implemented, the better performance the enterprise will have.

Preservation of tissue microstructure and functionality during freezing by modulation of cytoskeletal structure

PubMed Central

Park, Seungman; Seawright, Angela; Park, Sinwook; Dutton, J Craig; Grinnell, Frederick; Han, Bumsoo

2015-01-01

Cryopreservation is one of the key enabling technologies for tissue engineering and regenerative medicine, which can provide a reliable long-term storage of engineered tissues (ETs) without losing their functionality. However, it is still extremely difficult to design and develop cryopreservation protocols guaranteeing the post-thaw tissue functionality. One of the major challenges in cryopreservation is associated with the difficulty of identifying effective and less toxic cryoprotective agents (CPAs) to guarantee the post-thaw tissue functionality. In this study, thus, a hypothesis was tested that the modulation of the cytoskeletal structure of cells embedded in the extracellular matrix (ECM) can mitigate the freezing-induced changes of the functionality and can reduce the amount of CPA necessary to preserve the functionality of ETs during cryopreservation. In order to test this hypothesis, we prepared dermal equivalents by seeding fibroblasts in type I collagen matrices resulting in three different cytoskeletal structures. These ETs were exposed to various freeze/thaw (F/T) conditions with and without CPAs. The freezing-induced cell-fluid-matrix interactions and subsequent functional properties of the ETs were assessed. The results showed that the cytoskeletal structure and the use of CPA were strongly correlated to the preservation of the post-thaw functional properties. As the cytoskeletal structure became stronger via stress fiber formation, the ETs functionality was preserved better. It also reduced the necessary CPA concentration to preserve the post-thaw functionality. However, if the extent of the freezing-induced cell-fluid-matrix interaction was too excessive, the cytoskeletal structure was completely destroyed and the beneficial effects became minimal. PMID:25679482

Advances in the TRIDEC Cloud

NASA Astrophysics Data System (ADS)

Hammitzsch, Martin; Spazier, Johannes; Reißland, Sven

2016-04-01

The TRIDEC Cloud is a platform that merges several complementary cloud-based services for instant tsunami propagation calculations and automated background computation with graphics processing units (GPU), for web-mapping of hazard specific geospatial data, and for serving relevant functionality to handle, share, and communicate threat specific information in a collaborative and distributed environment. The platform offers a modern web-based graphical user interface so that operators in warning centres and stakeholders of other involved parties (e.g. CPAs, ministries) just need a standard web browser to access a full-fledged early warning and information system with unique interactive features such as Cloud Messages and Shared Maps. Furthermore, the TRIDEC Cloud can be accessed in different modes, e.g. the monitoring mode, which provides important functionality required to act in a real event, and the exercise-and-training mode, which enables training and exercises with virtual scenarios re-played by a scenario player. The software system architecture and open interfaces facilitate global coverage so that the system is applicable for any region in the world and allow the integration of different sensor systems as well as the integration of other hazard types and use cases different to tsunami early warning. Current advances of the TRIDEC Cloud platform will be summarized in this presentation.

Rapid freezing without cooling equilibration in canine sperm.

PubMed

Kim, Suhee; Lee, Yongcheol; Yang, Honghyun; Kim, Yong-Jun

2012-01-01

The aim of this study was to develop a rapid method of canine semen freezing without cooling equilibration using treatment with different cryoprotectant agents (CPAs) and freezing in liquid nitrogen (LN(2)) vapor in a 0.5-mL straw via modifying vitrification. Ejaculates from eight beagle dogs were frozen with different CPAs (CPA-free, 5% glycerol, 5% ethylene glycol, and 10% ethylene glycol) and freezing times (direct plunging into LN(2) or freezing for 1, 2, 3, or 10 min in LN(2) vapor before plunging into LN(2)). Frozen-thawed sperm were evaluated for motility, viability, normal morphology, and plasma- and acrosome-membrane integrities. The 5% glycerol treatment resulted in improved sperm motility, plasma-membrane integrity and acrosome-membrane integrity (P<0.05). Freezing in LN(2) vapor showed improved sperm motility, viability, and plasma membrane integrity (P<0.05), and freezing for more than 2 min in LN(2) vapor increased acrosome-membrane integrity compared with direct plunging into LN(2) (P<0.05). The direct plunging into LN(2) showed no motile sperm. However, freezing for more than 2 min in LN(2) vapor increased the total abnormalities compared to direct plunging into LN(2) (P<0.05). In conclusion, use of 5% glycerol and freezing in LN(2) vapor were essential for the rapid freezing of canine sperm without cooling equilibration. In particular, holding for 2 min in LN(2) vapor was sufficient to yield successful rapid freezing. This rapid freezing method is simple and effective in canine sperm and would be helpful to offer information for trial of vitrification in large volumes of canine sperm. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of trehalose as an additive to dimethyl sulfoxide solutions on ice formation, cellular viability, and metabolism.

PubMed

Solocinski, Jason; Osgood, Quinn; Wang, Mian; Connolly, Aaron; Menze, Michael A; Chakraborty, Nilay

2017-04-01

Cryopreservation is the only established method for long-term preservation of cells and cellular material. This technique involves preservation of cells and cellular components in the presence of cryoprotective agents (CPAs) at liquid nitrogen temperatures (-196 °C). The organic solvent dimethyl sulfoxide (Me 2 SO) is one of the most commonly utilized CPAs and has been used with various levels of success depending on the type of cells. In recent years, to improve cryogenic outcomes, the non-reducing disaccharide trehalose has been used as an additive to Me 2 SO-based freezing solutions. Trehalose is a naturally occurring non-toxic compound found in bacteria, fungi, plants, and invertebrates which has been shown to provide cellular protection during water-limited states. The mechanism by which trehalose improves cryopreservation outcomes remains not fully understood. Raman microspectroscopy is a powerful tool to provide valuable insight into the nature of interactions among water, trehalose, and Me 2 SO during cryopreservation. We found that the addition of trehalose to Me 2 SO based CPA solutions dramatically reduces the area per ice crystals while increasing the number of ice crystals formed when cooled to -40 or -80 °C. Differences in ice-formation patterns were found to have a direct impact on cellular viability. Despite the osmotic stress caused by addition of 100 mM trehalose, improvement in cellular viability was observed. However, the substantial increase in osmotic pressure caused by trehalose concentrations above 100 mM may offset the beneficial effects of changing the morphology of the ice crystals achieved by addition of this sugar. Copyright © 2017 Elsevier Inc. All rights reserved.

Equine ovarian tissue viability after cryopreservation and in vitro culture.

PubMed

Gastal, G D A; Aguiar, F L N; Alves, B G; Alves, K A; de Tarso, S G S; Ishak, G M; Cavinder, C A; Feugang, J M; Gastal, E L

2017-07-15

Ovarian tissue cryopreservation allows the preservation of the female fertility potential for an undetermined period. The objectives of this study were to compare the efficiency of cryoprotective agents (CPAs; dimethyl sulfoxide, DMSO; ethylene glycol, EG; and propylene glycol, PROH) using slow-freezing and vitrification methods, and evaluate the viability of cryopreserved equine ovarian tissue after 7 days of culture. Fresh and cryopreserved ovarian fragments were evaluated for preantral follicle morphology, stromal cell density, EGFR, Ki-67, Bax, and Bcl-2 protein expression, and DNA fragmentation. Vitrification with EG had the highest rate of morphologically normal preantral follicles, while DMSO had the lowest (76.1 ± 6.1% and 40.9 ± 14.8%, respectively; P < 0.05). In slow-freezing, despite that DMSO had the highest percentage of morphologically normal follicles (77.7 ± 5.8%), no difference among the CPAs was observed. Fluorescence intensity of EGFR and Ki-67 was greater when vitrification with EG was used. Regardless of the cryopreservation treatment, DMSO had the highest (P < 0.05) Bax/Bcl-2 ratio; however, DNA fragmentation was similar (P > 0.05) among treatments after thawing. After in vitro culture, the percentage of normal follicles was similar (P > 0.05) between slow-freezing and vitrification methods; however, vitrification had greater (P < 0.05) stromal cell density than slow-freezing. In summary, equine ovarian tissue was successfully cryopreserved, increasing the viability of the cells in the ovarian tissue after thawing when using DMSO and EG for slow-freezing and vitrification methods, respectively. Therefore, these results are relevant for fertility preservation programs. Copyright © 2017 Elsevier Inc. All rights reserved.

Cryopreservation of dermal fibroblasts and keratinocytes in hydroxyethyl starch-based cryoprotectants.

PubMed

Naaldijk, Yahaira; Johnson, Adiv A; Friedrich-Stöckigt, Annett; Stolzing, Alexandra

2016-12-01

Preservation of human skin fibroblasts and keratinocytes is essential for the creation of skin tissue banks. For successful cryopreservation of cells, selection of an appropriate cryoprotectant agent (CPA) is imperative. The aim of this study was to identify CPAs that minimize toxic effects and allow for the preservation of human fibroblasts and keratinocytes in suspension and in monolayers. We cryopreserved human fibroblasts and keratinocytes with different CPAs and compared them to fresh, unfrozen cells. Cells were frozen in the presence and absence of hydroxyethyl starch (HES) or dimethyl sulfoxide (DMSO), the latter of which is a commonly used CPA known to exert toxic effects on cells. Cell numbers were counted immediately post-thaw as well as three days after thawing. Cellular structures were analyzed and counted by labeling nuclei, mitochondria, and actin filaments. We found that successful cryopreservation of suspended or adherent keratinocytes can be accomplished with a 10% HES or a 5% HES, 5% DMSO solution. Cell viability of fibroblasts cryopreserved in suspension was maintained with 10% HES or 5% HES, 5% DMSO solutions. Adherent, cryopreserved fibroblasts were successfully maintained with a 5% HES, 5% DMSO solution. We conclude that skin tissue cells can be effectively cryopreserved by substituting all or a portion of DMSO with HES. Given that DMSO is the most commonly used CPA and is believed to be more toxic than HES, these findings are of clinical significance for tissue-based replacement therapies. Therapies that require the use of keratinocyte and fibroblast cells, such as those aimed at treating skin wounds or skin burns, may be optimized by substituting a portion or all of DMSO with HES during cryopreservation protocols.

A mixed methods evaluation of paediatric trainee preparedness to manage cardiopulmonary arrests.

PubMed

Walsh, Órla; Lydon, Sinéad; O'Connor, Paul

2017-12-01

Paediatric cardiopulmonary arrest (CPA) survival rates are strongly linked to the training of the doctors responding to the event. This study sought to characterise the level of experience in managing CPAs among paediatric trainees and to investigate the nontechnical (NTS) required to effectively lead a paediatric CPA team. A mixed-methods research design was used. For the quantitative phase, a questionnaire was developed to assess training, confidence, and experiences related to CPA management. During the qualitative phase, 17 paediatric trainees participated in a series of critical incident technique (CIT) interviews to explore the NTS used during the management of paediatric CPAs. A total of 56 of 131 (37.1% response rate) trainees responded to the preparedness questionnaire. A total of 48.2% of respondents expressed low confidence in their skill as a team leader during the management of a CPA. The CIT interviews highlighted deficiencies in specific NTS (identifying options, prioritising, and identifying and utilising resources). Our results indicate that there is a desire for more training in CPA management among paediatric trainees, in particular as a team leader, which includes a focus on key NTS. What is Known • Levels of preparedness to be a paediatric cardiopulmonary arrests team member/leader are generally lower than desirable. • The importance of nontechnical skills to the effective performance of adult cardiopulmonary arrests teams has been identified. What is New • Levels of preparedness to be a cardiopulmonary arrests team member were higher than reported in US studies. • There is a need for greater training in cardiopulmonary arrest management which includes a focus on key nontechnical skills to include identifying options, prioritising, identifying and utilising resources.

Effects of various combinations of cryoprotectants and cooling speed on the survival and further development of mouse oocytes after vitrification

PubMed Central

Cha, Soo Kyung; Kim, Bo Yeun; Kim, Mi Kyung; Kim, You Shin; Lee, Woo Sik

2011-01-01

Objective The objectives of this study were to analyze efficacy of immature and mature mouse oocytes after vitrification and warming by applying various combinations of cryoprotectants (CPAs) and/or super-rapid cooling using slush nitrogen (SN2). Methods Four-week old ICR female mice were superovulated for GV- and MII-stage oocytes. Experimental groups were divided into two groups. Ethylene glycol (EG) only group: pre-equilibrated with 1.5 M EG for 2.5 minutes and then equilibrated with 5.5 M EG and 1.0 M sucrose for 20 seconds. EG+dimethylsulfoxide (DMSO) group: pre-equilibrated with 1.3 M EG+1.1 M DMSO for 2.5 minutes and equilibrated with 2.7 M EG+2.1 M DMSO+0.5 M sucrose for 20 seconds. The oocytes were loaded onto grids and plunged into SN2 or liquid nitrogen (LN2). Stored oocytes were warmed by a five-step method, and then their survival, maturation, cleavage, and developmental rates were observed. Results The EG only and EG+DMSO groups showed no significant difference in survival of immature oocytes vitrified after warming. However, maturation and cleavage rates after conventional insemination were greater in the EG only group than in the EG+DMSO group. In mature oocytes, survival, cleavage, and blastocyst formation rates after warming showed no significant difference when EG only or EG+DMSO was applied. Furthermore, cleavage and blastocyst formation rates of MII oocytes vitrified using SN2 were increased in both the EG only and EG+DMSO groups. Conclusion A combination of CPAs in oocyte cryopreservation could be formulated according to the oocyte stage. In addition, SN2 may improve the efficiency of vitrification by reducing cryoinjury. PMID:22384414

Orion Parachute Riser Cutter Development

NASA Technical Reports Server (NTRS)

Oguz, Sirri; Salazar, Frank

2011-01-01

This paper presents the tests and analytical approach used on the development of a steel riser cutter for the CEV Parachute Assembly System (CPAS) used on the Orion crew module. Figure 1 shows the riser cutter and the steel riser bundle which consists of six individual cables. Due to the highly compressed schedule, initial unavailability of the riser material and the Orion Forward Bay mechanical constraints, JSC primarily relied on a combination of internal ballistics analysis and LS-DYNA simulation for this project. Various one dimensional internal ballistics codes that use standard equation of state and conservation of energy have commonly used in the development of CAD devices for initial first order estimates and as an enhancement to the test program. While these codes are very accurate for propellant performance prediction, they usually lack a fully defined kinematic model for dynamic predictions. A simple piston device can easily and accurately be modeled using an equation of motion. However, the accuracy of analytical models is greatly reduced on more complicated devices with complex external loads, nonlinear trajectories or unique unlocking features. A 3D finite element model of CAD device with all critical features included can vastly improve the analytical ballistic predictions when it is used as a supplement to the ballistic code. During this project, LS-DYNA structural 3D model was used to predict the riser resisting load that was needed for the ballistic code. A Lagrangian model with eroding elements shown in Figure 2 was used for the blade, steel riser and the anvil. The riser material failure strain was fine tuned by matching the dent depth on the anvil with the actual test data. LS-DYNA model was also utilized to optimize the blade tip design for the most efficient cut. In parallel, the propellant type and the amount were determined by using CADPROG internal ballistics code. Initial test results showed a good match with LS-DYNA and CADPROG simulations. Final paper will present a detailed roadmap from initial ballistic modeling and LS-DYNA simulation to the performance testing. Blade shape optimization study will also be presented.

Alginate beads as a tool to handle, cryopreserve and culture isolated human primordial/primary follicles.

PubMed

Camboni, A; Van Langendonckt, A; Donnez, J; Vanacker, J; Dolmans, M M; Amorim, C A

2013-08-01

One major concern of grafting cryopreserved ovarian tissue to restore fertility in cancer patients is the possibility of reintroducing tumor cells. Cryopreservation of isolated primordial/primary follicles (PFs) may circumvent this problem. The aim of our work was to compare dimethyl sulfoxide (ME2SO) and ethylene glycol (EG) as cryoprotectants (CPAs) for slow-freezing of isolated human PFs in alginate. Ovarian biopsies from four women were processed for follicle isolation. PFs were embedded in alginate (5-15 per group). Follicles were frozen-thawed using 1.4M ME2SO or 1.5M EG as CPAs. Fresh and cryopreserved isolated follicles were in vitro cultured (IVC) for 7 days. At different time periods (after isolation, cryopreservation and IVC), follicles were evaluated with live/dead assay (using fluorescent probes) and diameter measurement. Follicle viability was calculated according to the percentage of dead follicular cells and the presence of a live/dead oocyte. A total of 841 PFs were isolated, embedded in alginate and cryopreserved with ME2SO (n=424) or EG (n=259), or used as controls (n=158). After 7 days of IVC, a significant increase in follicle size was observed in the fresh and ME2SO groups, but not in the EG group. The percentage of totally viable PFs was not significantly different before or after seven days of culture in fresh (100% and 82%) or ME2SO (93.2% and 85.1%) tissue. The EG group showed significantly lower viability before (63.9%) and after IVC (66.2%) than the fresh and ME2SO groups. Our results show that 1.4M ME2SO yields better preservation of isolated PF viability after thawing and 7 days of IVC than 1.5M EG. Alginate constitutes an easy, safe hydrogel matrix to handle and cryopreserve isolated human follicles using ME2SO as a CPA. Copyright © 2013 Elsevier Inc. All rights reserved.

Assessment of strategies to increase chondrocyte viability in cryopreserved human osteochondral allografts: evaluation of the glycosylated hydroquinone, arbutin.

PubMed

Rosa, S C; Gonçalves, J; Judas, F; Lopes, C; Mendes, A F

2009-12-01

Allogeneic cartilage is used to repair damaged areas of articular cartilage, requiring the presence of living chondrocytes. So far, no preservation method can effectively meet that purpose. Identification of more effective cryoprotective agents (CPAs) can contribute to this goal. The aim of this study was to determine whether the glycosylated hydroquinone, arbutin, alone or in combination with low concentrations of other CPAs, has cryoprotective properties towards human articular cartilage. Human tibial plateaus were procured from multi-organ donors, with the approval of the Ethics Committee of the University Hospital of Coimbra. The tibial plateaus were treated with or without arbutin (50 or 100mM), alone or in combination with various concentrations of dimethyl sulfoxide (DMSO) and glycerol, for 0.5-1.5h/37 degrees C, then frozen at -20 degrees C and 24h later transferred to a biofreezer at -80 degrees C. Two to 3 months later, thawing was achieved by immersion in cell culture medium at 37 degrees C/1h. Chondrocyte viability was assessed before and after freeze-thawing using a colorimetric assay based on the cell's metabolic activity and fluorescent dyes to evaluate cell membrane integrity. Before freezing, chondrocyte metabolic activity was identical in all the conditions tested. After freeze-thawing, the highest activity, corresponding to 34.2+/-2.1% of that in the Fresh Control, was achieved in tibial plateaus incubated in 50mM arbutin for 1h whereas in those left untreated it was 11.1+/-4.7. Addition of DMSO and glycerol to arbutin did not increase chondrocyte viability any further. Fluorescence microscopy confirmed these results and showed that living chondrocytes were mainly restricted to the superficial cartilage layers. Arbutin seems to be an effective cryoprotective agent for osteochondral allografts with potential benefits over DMSO and glycerol.

Pediatric emergence delirium: Canadian Pediatric Anesthesiologists' experience.

PubMed

Rosen, H David; Mervitz, Deborah; Cravero, Joseph P

2016-02-01

Pediatric emergence agitation/delirium (ED) is a cluster of behaviors seen in the early postanesthetic period with negative emotional consequences for families and increased utilization of healthcare resources. Many studies have looked at identifying risk factors for ED and at pharmacologic regimens to prevent ED. There are few published reports on treatment options and efficacy for established ED episodes, and essentially no data concerning current practice in the treatment of ED. We sought to elicit the experience and opinions of Canadian Pediatric Anesthesiologists on the incidence of ED in their practice, definitions and diagnostic criteria, preventative strategies, treatments, and their perceived efficacy. A web-based survey was sent to pediatric anesthesiologists working at academic health science centers across Canada. The participants were selected based on being members of the Canadian Pediatric Anesthesia Society (CPAS), which represents the subspecialty in Canada. All members of CPAS who had e-mail contact information available in the membership database were invited to participate. A total of 209 members out of the total of 211 fulfilled these criteria and were included in the study population. The response rate was 51% (106/209). Of respondents, 42% felt that ED was a significant problem at their institutions, with 45% giving medication before or during anesthesia to prevent the development of ED. Propofol was the most common medication given to prevent ED (68%) and to treat ED (42%). Total intravenous anesthesia (TIVA) was considered by 38% of respondents as a technique used to prevent ED. Medications used for treatment included propofol (42%), midazolam (31%), fentanyl (10%), morphine (7%), and dexmedetomidine (5%), with 87% of respondents rating effectiveness of treatment as 'usually works quickly with one dose'. We present information on current practice patterns with respect to prophylaxis and treatment of ED among a specialized group of pediatric anesthesiologists and highlight the importance of further research in improving the treatment of this common and challenging peri-anesthetic occurrence. © 2015 John Wiley & Sons Ltd.

[Anti-HBV effects of genetically engineered replication-defective HBV with combined expression of antisense RNA and dominant negative mutants of core protein and construction of first-generation packaging cell line for HBV vector].

PubMed

Sun, Dian Xing; Hu, Da Rong; Wu, Guang Hui; Hu, Xue Ling; Li, Juan; Fan, Gong Ren

2002-08-01

To explore the possibility of using HBV as a gene delivery vector, and to test the anti-HBV effects by intracellular combined expression of antisense RNA and dominant negative mutants of core protein. Full length of mutant HBV genome, which expresses core-partial P fusion protein and/or antisense RNA, was transfected into HepG2.2.15 cell lines. Positive clones were selected and mixed in respective groups with hygromycin in the culture medium. HBsAg and HBeAg, which exist in the culture medium, were tested by ELISA method. Intracellular HBc related HBV DNA was examined by dot blot hybridization. The existence of recombinant HBV virion in the culture medium was examined by PCR. Free of packaging signal, HBV genome, which express the HBV structural proteins including core, pol and preS/S proteins, was inserted into pCI-neo vector. HepG2 cell lines were employed to transfect with the construct. G418 selection was done at the concentration of 400mug/ml in the culture medium. The G418-resistant clones with the best expression of HBsAg and HBcAg were theoretically considered as packaging cell lines and propagated under the same conditions. It was transfected with plasmid pMEP-CPAS and then selected with G418 and hygromycin in the culture medium. The existence of recombinant HBV virion in the culture medium was examined by PCR. The mean inhibitory rates of HBsAg were 2.74% 3.83%, 40.08 2.05% (t=35.5, P<0.01), 66.54% 4.45% (t=42.3, P<0.01), and 73.68% 5.07% (t=51.9, P<0.01) in group 2.2.15-pMEP4, 2.2.15-CP, 2.2.15-SAS, and 2.2.15-CPAS, respectively. The mean inhibitory rates of HBeAg were 4.46% 4.25%, 52.86% 1.32% (t=36.2, P<0.01), 26.36% 1.69% (t=22.3, P<0.01), and 59.28% 2.10% (t=39.0, P<0.01), respectively. The inhibitory rates of HBc related HBV DNA were 0, 82.0%, 59.9%, and 96.6%, respectively. Recombinant HB virion was detectable in the culture medium of all the three treatment groups. G418-resistant HBV packaging cell line, which harbored an HBV mutant whose packaging signal had been deleted, was generated. Expression of HBsAg and HBcAg was detectable. Transfected with plasmid pMEP-CPAS, it was found to secrete recombinant HB virion and no wild-type HBV was detectable in the culture medium. It has stronger anti-HBV effects by combined expression of antisense RNA and dominant negative mutants than by individual expression of them. With the help of wild-type HBV, the modified HBV genome can form and secret HBV like particles, which provides evidence that the antiviral gene will be hepatotropic expression and the antiviral effects will be amplified. The packaging cell line can provide packaging for replication-defective HBV, but with low efficiency.

Electrolytic oxide reduction system

DOEpatents

Wiedmeyer, Stanley G; Barnes, Laurel A; Williamson, Mark A; Willit, James L; Berger, John F

2015-04-28

An electrolytic oxide reduction system according to a non-limiting embodiment of the present invention may include a plurality of anode assemblies, a plurality of cathode assemblies, and a lift system configured to engage the anode and cathode assemblies. The cathode assemblies may be alternately arranged with the anode assemblies such that each cathode assembly is flanked by two anode assemblies. The lift system may be configured to selectively engage the anode and cathode assemblies so as to allow the simultaneous lifting of any combination of the anode and cathode assemblies (whether adjacent or non-adjacent).

Anode-cathode power distribution systems and methods of using the same for electrochemical reduction

DOEpatents

Koehl, Eugene R; Barnes, Laurel A; Wiedmeyer, Stanley G; Williamson, Mark A; Willit, James L

2014-01-28

Power distribution systems are useable in electrolytic reduction systems and include several cathode and anode assembly electrical contacts that permit flexible modular assembly numbers and placement in standardized connection configurations. Electrical contacts may be arranged at any position where assembly contact is desired. Electrical power may be provided via power cables attached to seating assemblies of the electrical contacts. Cathode and anode assembly electrical contacts may provide electrical power at any desired levels. Pairs of anode and cathode assembly electrical contacts may provide equal and opposite electrical power; different cathode assembly electrical contacts may provide different levels of electrical power to a same or different modular cathode assembly. Electrical systems may be used with an electrolyte container into which the modular cathode and anode assemblies extend and are supported above, with the modular cathode and anode assemblies mechanically and electrically connecting to the respective contacts in power distribution systems.

Probe tip heating assembly

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

Schmitz, Roger William; Oh, Yunje

A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably receivedmore » and clamped within the socket.« less

Host-regulated Hepatitis B Virus Capsid Assembly in a Mammalian Cell-free System.

PubMed

Liu, Kuancheng; Hu, Jianming

2018-04-20

The hepatitis B virus (HBV) is an important global human pathogen and represents a major cause of hepatitis, liver cirrhosis and liver cancer. The HBV capsid is composed of multiple copies of a single viral protein, the capsid or core protein (HBc), plays multiple roles in the viral life cycle, and has emerged recently as a major target for developing antiviral therapies against HBV infection. Although several systems have been developed to study HBV capsid assembly, including heterologous overexpression systems like bacteria and insect cells, in vitro assembly using purified protein, and mammalian cell culture systems, the requirement for non-physiological concentrations of HBc and salts and the difficulty in manipulating host regulators of assembly presents major limitations for detailed studies on capsid assembly under physiologically relevant conditions. We have recently developed a mammalian cell-free system based on the rabbit reticulocyte lysate (RRL), in which HBc is expressed at physiological concentrations and assembles into capsids under near-physiological conditions. This system has already revealed HBc assembly requirements that are not anticipated based on previous assembly systems. Furthermore, capsid assembly in this system is regulated by endogenous host factors that can be readily manipulated. Here we present a detailed protocol for this cell-free capsid assembly system, including an illustration on how to manipulate host factors that regulate assembly.

Quantitative computational models of molecular self-assembly in systems biology

PubMed Central

Thomas, Marcus; Schwartz, Russell

2017-01-01

Molecular self-assembly is the dominant form of chemical reaction in living systems, yet efforts at systems biology modeling are only beginning to appreciate the need for and challenges to accurate quantitative modeling of self-assembly. Self-assembly reactions are essential to nearly every important process in cell and molecular biology and handling them is thus a necessary step in building comprehensive models of complex cellular systems. They present exceptional challenges, however, to standard methods for simulating complex systems. While the general systems biology world is just beginning to deal with these challenges, there is an extensive literature dealing with them for more specialized self-assembly modeling. This review will examine the challenges of self-assembly modeling, nascent efforts to deal with these challenges in the systems modeling community, and some of the solutions offered in prior work on self-assembly specifically. The review concludes with some consideration of the likely role of self-assembly in the future of complex biological system models more generally. PMID:28535149

Quantitative computational models of molecular self-assembly in systems biology.

PubMed

Thomas, Marcus; Schwartz, Russell

2017-05-23

Molecular self-assembly is the dominant form of chemical reaction in living systems, yet efforts at systems biology modeling are only beginning to appreciate the need for and challenges to accurate quantitative modeling of self-assembly. Self-assembly reactions are essential to nearly every important process in cell and molecular biology and handling them is thus a necessary step in building comprehensive models of complex cellular systems. They present exceptional challenges, however, to standard methods for simulating complex systems. While the general systems biology world is just beginning to deal with these challenges, there is an extensive literature dealing with them for more specialized self-assembly modeling. This review will examine the challenges of self-assembly modeling, nascent efforts to deal with these challenges in the systems modeling community, and some of the solutions offered in prior work on self-assembly specifically. The review concludes with some consideration of the likely role of self-assembly in the future of complex biological system models more generally.

ASSEMBLY TRANSFER SYSTEM DESCRIPTION DOCUMENT

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

B. Gorpani

2000-06-26

The Assembly Transfer System (ATS) receives, cools, and opens rail and truck transportation casks from the Carrier/Cask Handling System (CCHS). The system unloads transportation casks consisting of bare Spent Nuclear Fuel (SNF) assemblies, single element canisters, and Dual Purpose Canisters (DPCs). For casks containing DPCs, the system opens the DPCs and unloads the SNF. The system stages the assemblies, transfer assemblies to and from fuel-blending inventory pools, loads them into Disposal Containers (DCs), temporarily seals and inerts the DC, decontaminates the DC and transfers it to the Disposal Container Handling System. The system also prepares empty casks and DPCs formore » off-site shipment. Two identical Assembly Transfer System lines are provided in the Waste Handling Building (WHB). Each line operates independently to handle the waste transfer throughput and to support maintenance operations. Each system line primarily consists of wet and dry handling areas. The wet handling area includes a cask transport system, cask and DPC preparation system, and a wet assembly handling system. The basket transport system forms the transition between the wet and dry handling areas. The dry handling area includes the dry assembly handling system, assembly drying system, DC preparation system, and DC transport system. Both the wet and dry handling areas are controlled by the control and tracking system. The system operating sequence begins with moving transportation casks to the cask preparation area. The cask preparation operations consist of cask cavity gas sampling, cask venting, cask cool-down, outer lid removal, and inner shield plug lifting fixture attachment. Casks containing bare SNF (no DPC) are filled with water and placed in the cask unloading pool. The inner shield plugs are removed underwater. For casks containing a DPC, the cask lid(s) is removed, and the DPC is penetrated, sampled, vented, and cooled. A DPC lifting fixture is attached and the cask is placed into the cask unloading pool. In the cask unloading pool the DPC is removed from the cask and placed in an overpack and the DPC lid is severed and removed. Assemblies are removed from either an open cask or DPC and loaded into assembly baskets positioned in the basket staging rack in the assembly unloading pool. A method called ''blending'' is utilized to load DCs with a heat output of less than 11.8 kW. This involves combining hotter and cooler assemblies from different baskets. Blending requires storing some of the hotter fuel assemblies in fuel-blending inventory pools until cooler assemblies are available. The assembly baskets are then transferred from the basket staging rack to the assembly handling cell and loaded into the assembly drying vessels. After drying, the assemblies are removed from the assembly drying vessels and loaded into a DC positioned below the DC load port. After installation of a DC inner lid and temporary sealing device, the DC is transferred to the DC decontamination cell where the top area of the DC, the DC lifting collar, and the DC inner lid and temporary sealing device are decontaminated, and the DC is evacuated and backfilled with inert gas to prevent prolonged clad exposure to air. The DC is then transferred to the Disposal Container Handling System for lid welding. In another cask preparation and decontamination area, lids are replaced on the empty transportation casks and DPC overpacks, the casks and DPC overpacks are decontaminated, inspected, and transferred to the Carrier/Cask Handling System for shipment off-site. All system equipment is designed to facilitate manual or remote operation, decontamination, and maintenance. The system interfaces with the Carrier/Cask Handling System for incoming and outgoing transportation casks and DPCs. The system also interfaces with the Disposal Container Handling System, which prepares the DC for loading and subsequently seals the loaded DC. The system support interfaces are the Waste Handling Building System and other internal WHB support systems.« less

Development of a Collaborative Practice Agreement Template to Promote the Role of the Pharmacist in Managing Urinary Tract Infections in Long-term Care Residents

PubMed Central

Fehrenbacher, Lynne; McDevitt, Kimberly; Palmer, Matthew; Traynor, Laura; Boero, Joe; Crnich, Christopher

2017-01-01

Abstract Background One of the CDC core elements of antimicrobial stewardship in nursing homes emphasizes the promotion of clinical practice change and integration of the dispensing and consultant pharmacist to improve antibiotic use. An opportunity to support this element is via collaborative practice agreements (CPA). A CPA is a voluntary agreement between one or more prescribers and pharmacists which delegates physician authority under defined conditions and/or limitations toward a common goal. The Wisconsin Healthcare-Associated Infections (HAI) in Long-term Care (LTC) Coalition aims to reduce and eliminate HAIs among LTC residents. A coalition emphasis has been to educate caregivers about appropriate evaluation and treatment of suspected urinary tract infection (UTI). Given this focus, we targeted the same cohort for CPA design. Methods A literature review resulted in no report of CPAs being applied to LTC residents on antibiotics for UTI. Recognizing the dispensing and consultant pharmacist role varies by organization, we drafted a multi-layered CPA that can be customized by facility. The draft was reviewed by physicians, pharmacists, and nurses with expertise in infectious diseases, LTC, and CPAs. Through frequent meetings and collaborative editing, consensus was achieved. The final CPA includes antibiotic renal dose adjustment, discontinuation of antibiotics in asymptomatic patients with negative urinalysis or culture, and oral antibiotic modification based on organism susceptibility. Results The CPA template is supported by the WI HAI in LTC Coalition. It has been presented at the state level and is available for use by LTC facilities and pharmacists that may apply any/all level(s) of the CPA. An organization policy template and initial CPA competency for pharmacists have been designed to support implementation. Committed pilot sites have been identified. Conclusion A CPA is an innovative approach to expand the role of the dispensing and consultant pharmacist in antimicrobial stewardship initiatives in the LTC setting. Using an expert panel to develop templated resources that can be customized at the facility level may assist pharmacists and LTC providers in moving forward with this type of clinical practice change. Disclosures All authors: No reported disclosures.

Survey of pediatric resident experiences with resuscitation training and attendance at actual cardiopulmonary arrests.

PubMed

Hunt, Elizabeth A; Patel, Sachin; Vera, Kimberly; Shaffner, Donald H; Pronovost, Peter J

2009-01-01

The literature suggests pediatric residents are inadequately prepared to perform resuscitation maneuvers when a child suffers a cardiopulmonary arrest (CPA). Our objective was to characterize the resuscitation training and CPA resuscitation experience of residents, including hands on experience with discharging a defibrillator. : Cross-sectional survey. Tertiary care, academic pediatric residency program. Pediatric residents. Seventy-six of 80 (95%) pediatric residents responded. The median (interquartile range) number of CPAs attended increased significantly by level of training, with some attending as many as 20 CPAs during residency (postgraduate year [PGY]1: 2.0 [1.0-3.0] vs. PGY2: 5.0 [3.0-8.0] vs. PGY3: 10.0 [5.0-12.0], p < 0.001). Nine of 25 (36%) senior residents had led a resuscitation. The proportion of third-year residents who had attended at least 1 CPA in the following locations was: general ward 20 of 25 (80%), Emergency Department 18 of 25 (72%), Neonatal intensive care unit 24 of 25 (96%), pediatric intensive care unit 23 of 25 (92%), and secondary training hospital 19 of 25 (76%). Twelve of 76 (16%) residents had discharged a defibrillator on an actual patient; however, 25 of 76 (33%) had never discharged a defibrillator, either on a patient or during training exercises. Although most residents had received required training in American Heart Association Basic Life Support and Pediatric Advance Life Support (i.e., BLS and PALS), 6 of 76 (8%) residents had never taken basic life support and 4 of 48 (8%) of upper level residents had never taken pediatric advanced life support. Multivariate analysis revealed that level of training, pediatric advanced life support training, and attendance at a mock code in the past year were not independently associated with having discharged a defibrillator (i.e., patient, mannequin, etc.), whereas attendance at an institutional Code Team training course was. Almost every pediatric resident was involved in attempting to resuscitate a child suffering a CPA, yet many were inadequately trained to respond. Formal mechanisms are needed to guarantee adequate resuscitation training for pediatric residents, especially regarding participation in basic life support and hands on defibrillator training.

System and method for controlling a combustor assembly

DOEpatents

York, William David; Ziminsky, Willy Steve; Johnson, Thomas Edward; Stevenson, Christian Xavier

2013-03-05

A system and method for controlling a combustor assembly are disclosed. The system includes a combustor assembly. The combustor assembly includes a combustor and a fuel nozzle assembly. The combustor includes a casing. The fuel nozzle assembly is positioned at least partially within the casing and includes a fuel nozzle. The fuel nozzle assembly further defines a head end. The system further includes a viewing device configured for capturing an image of at least a portion of the head end, and a processor communicatively coupled to the viewing device, the processor configured to compare the image to a standard image for the head end.

Backward assembly planning with DFA analysis

NASA Technical Reports Server (NTRS)

Lee, Sukhan (Inventor)

1992-01-01

An assembly planning system that operates based on a recursive decomposition of assembly into subassemblies is presented. The planning system analyzes assembly cost in terms of stability, directionality, and manipulability to guide the generation of preferred assembly plans. The planning in this system incorporates the special processes, such as cleaning, testing, labeling, etc., that must occur during the assembly. Additionally, the planning handles nonreversible, as well as reversible, assembly tasks through backward assembly planning. In order to decrease the planning efficiency, the system avoids the analysis of decompositions that do not correspond to feasible assembly tasks. This is achieved by grouping and merging those parts that can not be decomposable at the current stage of backward assembly planning due to the requirement of special processes and the constraint of interconnection feasibility. The invention includes methods of evaluating assembly cost in terms of the number of fixtures (or holding devices) and reorientations required for assembly, through the analysis of stability, directionality, and manipulability. All these factors are used in defining cost and heuristic functions for an AO* search for an optimal plan.

Human Factors and Their Effects on Human-Centred Assembly Systems - A Literature Review-Based Study

NASA Astrophysics Data System (ADS)

Wang, Q.; Abubakar, M. I.

2017-09-01

If a product has more than one component, then it must be assembled. Assembly of products relies on assembly systems or lines in which assembly of each product is often carried out manually by human workers following assembly sequences in various forms. It is widely understood that efficiency of assembling a product by reducing assembly times (therefore costs) is vital particularly for small and medium-sized manufacturing companies to survive in an increasingly competitive market. Ideally, it is helpful for pre-determining efficiency or productivity of a human-centred assembly system at the early design stage. To date, most research on performance of an assembly system using modelling simulation methods is focused on its “operational functions”. The term used in a narrow sense always indicates the performance of the “operational system”, which does not incorporate the effect of human factors that may also affect the system performance. This paper presents a research outcome of findings through a literature review-based study by identifying possible human factors that mostly affect the performance on human-centred manufacturing systems as part of the research project incorporating parameters of human factors into a DES (discrete event simulation) tool.

The precision measurement and assembly for miniature parts based on double machine vision systems

NASA Astrophysics Data System (ADS)

Wang, X. D.; Zhang, L. F.; Xin, M. Z.; Qu, Y. Q.; Luo, Y.; Ma, T. M.; Chen, L.

2015-02-01

In the process of miniature parts' assembly, the structural features on the bottom or side of the parts often need to be aligned and positioned. The general assembly equipment integrated with one vertical downward machine vision system cannot satisfy the requirement. A precision automatic assembly equipment was developed with double machine vision systems integrated. In the system, a horizontal vision system is employed to measure the position of the feature structure at the parts' side view, which cannot be seen with the vertical one. The position measured by horizontal camera is converted to the vertical vision system with the calibration information. By careful calibration, the parts' alignment and positioning in the assembly process can be guaranteed. The developed assembly equipment has the characteristics of easy implementation, modularization and high cost performance. The handling of the miniature parts and assembly procedure were briefly introduced. The calibration procedure was given and the assembly error was analyzed for compensation.

Food System Trade Study for a Near-Term Mars Mission

NASA Technical Reports Server (NTRS)

Levri, Julie; Luna, Bernadette (Technical Monitor)

2000-01-01

This paper evaluates several food system options for a near-term Mars mission, based on plans for the 120-day BIO-Plex test. Food systems considered in the study are based on the International Space Station (ISS) Assembly Phase and Assembly Complete food systems. The four systems considered are: 1) ISS assembly phase food system (US portion) with individual packaging without salad production; 2) ISS assembly phase food system (US portion) with individual packaging, with salad production; 3) ISS assembly phase food system (US portion) with bulk packaging, with salad production; 4) ISS assembly complete food system (US portion) with bulk packaging with salad and refrigeration/freezing. The food system options are assessed using equivalent system mass (ESM), which evaluates each option based upon the mass, volume, power, cooling and crewtime requirements that are associated with each food system option. However, since ESM is unable to elucidate the differences in psychological benefits between the food systems, a qualitative evaluation of each option is also presented.

Magnetic-graphitic-nanocapsule templated diacetylene assembly and photopolymerization for sensing and multicoded anti-counterfeiting

NASA Astrophysics Data System (ADS)

Nie, Xiang-Kun; Xu, Yi-Ting; Song, Zhi-Ling; Ding, Ding; Gao, Feng; Liang, Hao; Chen, Long; Bian, Xia; Chen, Zhuo; Tan, Weihong

2014-10-01

Molecular self-assembly, a process to design molecular entities to aggregate into desired structures, represents a promising bottom-up route towards precise construction of functional systems. Here we report a multifunctional, self-assembled system based on magnetic-graphitic-nanocapsule (MGN) templated diacetylene assembly and photopolymerization. The as-prepared assembly system maintains the unique color and fluorescence change properties of the polydiacetylene (PDA) polymers, while also pursues the superior Raman, NIR, magnetic and superconducting properties from the MGN template. Based on both fluorescence and magnetic resonance imaging (MRI) T2 relaxivity, the MGN@PDA system could efficiently monitor the pH variations which could be used as a pH sensor. The MGN@PDA system further demonstrates potential as unique ink for anti-counterfeiting applications. Reversible color change, strong and unique Raman scattering and fluorescence emission, sensitive NIR thermal response, and distinctive magnetic properties afford this assembly system with multicoded anti-counterfeiting capabilities.Molecular self-assembly, a process to design molecular entities to aggregate into desired structures, represents a promising bottom-up route towards precise construction of functional systems. Here we report a multifunctional, self-assembled system based on magnetic-graphitic-nanocapsule (MGN) templated diacetylene assembly and photopolymerization. The as-prepared assembly system maintains the unique color and fluorescence change properties of the polydiacetylene (PDA) polymers, while also pursues the superior Raman, NIR, magnetic and superconducting properties from the MGN template. Based on both fluorescence and magnetic resonance imaging (MRI) T2 relaxivity, the MGN@PDA system could efficiently monitor the pH variations which could be used as a pH sensor. The MGN@PDA system further demonstrates potential as unique ink for anti-counterfeiting applications. Reversible color change, strong and unique Raman scattering and fluorescence emission, sensitive NIR thermal response, and distinctive magnetic properties afford this assembly system with multicoded anti-counterfeiting capabilities. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03837a

Backward assembly planning with DFA analysis

NASA Technical Reports Server (NTRS)

Lee, Sukhan (Inventor)

1995-01-01

An assembly planning system that operates based on a recursive decomposition of assembly into subassemblies, and analyzes assembly cost in terms of stability, directionality, and manipulability to guide the generation of preferred assembly plans is presented. The planning in this system incorporates the special processes, such as cleaning, testing, labeling, etc. that must occur during the assembly, and handles nonreversible as well as reversible assembly tasks through backward assembly planning. In order to increase the planning efficiency, the system avoids the analysis of decompositions that do not correspond to feasible assembly tasks. This is achieved by grouping and merging those parts that can not be decomposable at the current stage of backward assembly planning due to the requirement of special processes and the constraint of interconnection feasibility. The invention includes methods of evaluating assembly cost in terms of the number of fixtures (or holding devices) and reorientations required for assembly, through the analysis of stability, directionality, and manipulability. All these factors are used in defining cost and heuristic functions for an AO* search for an optimal plan.

Cryopreservation of umbilical cord blood-derived mesenchymal stem cells without dimethyl sulfoxide.

PubMed

Wang, Hai-Yan; Lun, Zhao-Rong; Lu, Shu-Shen

2011-01-01

Cryopreservation of umbilical cord blood-derived mesenchymal stem cells (UCB-derived MSCs) is crucial step for its clinical applications in cell transplantation therapy. In the cryopreservation of MSCs, dimethyl sulfoxide has been widely used as a cryoprotectant (CPA). However, it has been proved that DMSO has toxic side effects to human body. In this study, DMSO-free CPA solutions which contained ethylene glycol (EG), 1, 2-propylene glycol (PG) and sucrose as basic CPAs, supplemented with polyvinyl alcohol (PVA) as an additive, were developed for the cryopreservation of UCB-derived MSCs. The cryopreservation of UCB-derived MSCs was achieved by vitrification via plunging into liquid nitrogen and by programmed freezing via an optical-DSC system respectively. The viability of thawed UCB-derived MSCs was tested by trypan blue exclusion assay. Results showed that the viability of thawed UCB-derived MSCs was enhanced from 71.2% to 95.4% in the presence of PVA for vitrification, but only < 10% to 45% of viability was found for programmed freezing. These results indicate that PVA exerts a beneficial effect on the cryopreservation of UCB-derived MSCs and suggest the vitrification in combination with the dimethyl sulfoxide free CPA solutions supplemented with PVA would be an efficient protocol for the cryopreservation of UCB-derived MSCs.

Toward a molecular programming language for algorithmic self-assembly

NASA Astrophysics Data System (ADS)

Patitz, Matthew John

Self-assembly is the process whereby relatively simple components autonomously combine to form more complex objects. Nature exhibits self-assembly to form everything from microscopic crystals to living cells to galaxies. With a desire to both form increasingly sophisticated products and to understand the basic components of living systems, scientists have developed and studied artificial self-assembling systems. One such framework is the Tile Assembly Model introduced by Erik Winfree in 1998. In this model, simple two-dimensional square 'tiles' are designed so that they self-assemble into desired shapes. The work in this thesis consists of a series of results which build toward the future goal of designing an abstracted, high-level programming language for designing the molecular components of self-assembling systems which can perform powerful computations and form into intricate structures. The first two sets of results demonstrate self-assembling systems which perform infinite series of computations that characterize computably enumerable and decidable languages, and exhibit tools for algorithmically generating the necessary sets of tiles. In the next chapter, methods for generating tile sets which self-assemble into complicated shapes, namely a class of discrete self-similar fractal structures, are presented. Next, a software package for graphically designing tile sets, simulating their self-assembly, and debugging designed systems is discussed. Finally, a high-level programming language which abstracts much of the complexity and tedium of designing such systems, while preventing many of the common errors, is presented. The summation of this body of work presents a broad coverage of the spectrum of desired outputs from artificial self-assembling systems and a progression in the sophistication of tools used to design them. By creating a broader and deeper set of modular tools for designing self-assembling systems, we hope to increase the complexity which is attainable. These tools provide a solid foundation for future work in both the Tile Assembly Model and explorations into more advanced models.

Optical Assembly and Characterization System for Nano-Photonics Research

DTIC Science & Technology

2016-03-01

Unlimited Final Report: Optical Assembly and Characterization System for Nano -Photonics Research The views, opinions and/or findings contained in this...reviewed journals: Final Report: Optical Assembly and Characterization System for Nano -Photonics Research Report Title With this equipment funding support...Assembly and Characterization System for Nano -Photonics Research PI: Prof. Weidong Zhou, University of Texas at Arlington (UTA) 500 S. Cooper St

Modular cathode assemblies and methods of using the same for electrochemical reduction

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

Wiedmeyer, Stanley G.; Barnes, Laurel A.; Williamson, Mark A.

Modular cathode assemblies are useable in electrolytic reduction systems and include a basket through which fluid electrolyte may pass and exchange charge with a material to be reduced in the basket. The basket can be divided into upper and lower sections to provide entry for the material. Example embodiment cathode assemblies may have any shape to permit modular placement at any position in reduction systems. Modular cathode assemblies include a cathode plate in the basket, to which unique and opposite electrical power may be supplied. Example embodiment modular cathode assemblies may have standardized electrical connectors. Modular cathode assemblies may bemore » supported by a top plate of an electrolytic reduction system. Electrolytic oxide reduction systems are operated by positioning modular cathode and anode assemblies at desired positions, placing a material in the basket, and charging the modular assemblies to reduce the metal oxide.« less

Modular cathode assemblies and methods of using the same for electrochemical reduction

DOEpatents

Wiedmeyer, Stanley G; Barnes, Laurel A; Williamson, Mark A; Willit, James L

2014-12-02

Modular cathode assemblies are useable in electrolytic reduction systems and include a basket through which fluid electrolyte may pass and exchange charge with a material to be reduced in the basket. The basket can be divided into upper and lower sections to provide entry for the material. Example embodiment cathode assemblies may have any shape to permit modular placement at any position in reduction systems. Modular cathode assemblies include a cathode plate in the basket, to which unique and opposite electrical power may be supplied. Example embodiment modular cathode assemblies may have standardized electrical connectors. Modular cathode assemblies may be supported by a top plate of an electrolytic reduction system. Electrolytic oxide reduction systems are operated by positioning modular cathode and anode assemblies at desired positions, placing a material in the basket, and charging the modular assemblies to reduce the metal oxide.

Modular anode assemblies and methods of using the same for electrochemical reduction

DOEpatents

Wiedmeyer, Stanley G; Barnes, Laurel A; Williamson, Mark A; Willit, James L

2015-02-17

Modular anode assemblies are used in electrolytic oxide reduction systems for scalable reduced metal production via electrolysis. Assemblies include a channel frame connected to several anode rods extending into an electrolyte. An electrical system powers the rods while being insulated from the channel frame. A cooling system removes heat from anode rods and the electrical system. An anode guard attaches to the channel frame to prevent accidental electrocution or damage during handling or repositioning. Each anode rod may be divided into upper and lower sections to permit easy repair and swapping out of lower sections. The modular assemblies may have standardized components to permit placement at multiple points within a reducing system. Example methods may operate an electrolytic oxide reduction system by positioning the modular anode assemblies in the reduction system and applying electrical power to the plurality of anode assemblies.

Collaborated measurement of three-dimensional position and orientation errors of assembled miniature devices with two vision systems

NASA Astrophysics Data System (ADS)

Wang, Xiaodong; Zhang, Wei; Luo, Yi; Yang, Weimin; Chen, Liang

2013-01-01

In assembly of miniature devices, the position and orientation of the parts to be assembled should be guaranteed during or after assembly. In some cases, the relative position or orientation errors among the parts can not be measured from only one direction using visual method, because of visual occlusion or for the features of parts located in a three-dimensional way. An automatic assembly system for precise miniature devices is introduced. In the modular assembly system, two machine vision systems were employed for measurement of the three-dimensionally distributed assembly errors. High resolution CCD cameras and high position repeatability precision stages were integrated to realize high precision measurement in large work space. The two cameras worked in collaboration in measurement procedure to eliminate the influence of movement errors of the rotational or translational stages. A set of templates were designed for calibration of the vision systems and evaluation of the system's measurement accuracy.

Cathode power distribution system and method of using the same for power distribution

DOEpatents

Williamson, Mark A; Wiedmeyer, Stanley G; Koehl, Eugene R; Bailey, James L; Willit, James L; Barnes, Laurel A; Blaskovitz, Robert J

2014-11-11

Embodiments include a cathode power distribution system and/or method of using the same for power distribution. The cathode power distribution system includes a plurality of cathode assemblies. Each cathode assembly of the plurality of cathode assemblies includes a plurality of cathode rods. The system also includes a plurality of bus bars configured to distribute current to each of the plurality of cathode assemblies. The plurality of bus bars include a first bus bar configured to distribute the current to first ends of the plurality of cathode assemblies and a second bus bar configured to distribute the current to second ends of the plurality of cathode assemblies.

Electrical power system WP-04

NASA Astrophysics Data System (ADS)

Nored, Donald L.

Viewgraphs on Space Station Freedom Electrical Power System (EPS) WP-40 are presented. Topics covered include: key EPS technical requirements; photovoltaic power module systems; solar array assembly; blanket containment box and box positioning subassemblies; solar cell; bypass diode assembly; Kapton with atomic oxygen resistant coating; sequential shunt unit; gimbal assembly; energy storage subsystem; thermal control subsystem; direct current switching unit; integrated equipment assembly; PV cargo element; PMAD system; and PMC and AC architecture.

Electrical power system WP-04

NASA Technical Reports Server (NTRS)

Nored, Donald L.

1990-01-01

Viewgraphs on Space Station Freedom Electrical Power System (EPS) WP-40 are presented. Topics covered include: key EPS technical requirements; photovoltaic power module systems; solar array assembly; blanket containment box and box positioning subassemblies; solar cell; bypass diode assembly; Kapton with atomic oxygen resistant coating; sequential shunt unit; gimbal assembly; energy storage subsystem; thermal control subsystem; direct current switching unit; integrated equipment assembly; PV cargo element; PMAD system; and PMC and AC architecture.

Probabilistic Analysis of Pattern Formation in Monotonic Self-Assembly

PubMed Central

Moore, Tyler G.; Garzon, Max H.; Deaton, Russell J.

2015-01-01

Inspired by biological systems, self-assembly aims to construct complex structures. It functions through piece-wise, local interactions among component parts and has the potential to produce novel materials and devices at the nanoscale. Algorithmic self-assembly models the product of self-assembly as the output of some computational process, and attempts to control the process of assembly algorithmically. Though providing fundamental insights, these computational models have yet to fully account for the randomness that is inherent in experimental realizations, which tend to be based on trial and error methods. In order to develop a method of analysis that addresses experimental parameters, such as error and yield, this work focuses on the capability of assembly systems to produce a pre-determined set of target patterns, either accurately or perhaps only approximately. Self-assembly systems that assemble patterns that are similar to the targets in a significant percentage are “strong” assemblers. In addition, assemblers should predominantly produce target patterns, with a small percentage of errors or junk. These definitions approximate notions of yield and purity in chemistry and manufacturing. By combining these definitions, a criterion for efficient assembly is developed that can be used to compare the ability of different assembly systems to produce a given target set. Efficiency is a composite measure of the accuracy and purity of an assembler. Typical examples in algorithmic assembly are assessed in the context of these metrics. In addition to validating the method, they also provide some insight that might be used to guide experimentation. Finally, some general results are established that, for efficient assembly, imply that every target pattern is guaranteed to be assembled with a minimum common positive probability, regardless of its size, and that a trichotomy exists to characterize the global behavior of typical efficient, monotonic self-assembly systems in the literature. PMID:26421616

A parameter estimation technique for stochastic self-assembly systems and its application to human papillomavirus self-assembly.

PubMed

Kumar, M Senthil; Schwartz, Russell

2010-12-09

Virus capsid assembly has been a key model system for studies of complex self-assembly but it does pose some significant challenges for modeling studies. One important limitation is the difficulty of determining accurate rate parameters. The large size and rapid assembly of typical viruses make it infeasible to directly measure coat protein binding rates or deduce them from the relatively indirect experimental measures available. In this work, we develop a computational strategy to deduce coat-coat binding rate parameters for viral capsid assembly systems by fitting stochastic simulation trajectories to experimental measures of assembly progress. Our method combines quadratic response surface and quasi-gradient descent approximations to deal with the high computational cost of simulations, stochastic noise in simulation trajectories and limitations of the available experimental data. The approach is demonstrated on a light scattering trajectory for a human papillomavirus (HPV) in vitro assembly system, showing that the method can provide rate parameters that produce accurate curve fits and are in good concordance with prior analysis of the data. These fits provide an insight into potential assembly mechanisms of the in vitro system and give a basis for exploring how these mechanisms might vary between in vitro and in vivo assembly conditions.

A parameter estimation technique for stochastic self-assembly systems and its application to human papillomavirus self-assembly

NASA Astrophysics Data System (ADS)

Senthil Kumar, M.; Schwartz, Russell

2010-12-01

Virus capsid assembly has been a key model system for studies of complex self-assembly but it does pose some significant challenges for modeling studies. One important limitation is the difficulty of determining accurate rate parameters. The large size and rapid assembly of typical viruses make it infeasible to directly measure coat protein binding rates or deduce them from the relatively indirect experimental measures available. In this work, we develop a computational strategy to deduce coat-coat binding rate parameters for viral capsid assembly systems by fitting stochastic simulation trajectories to experimental measures of assembly progress. Our method combines quadratic response surface and quasi-gradient descent approximations to deal with the high computational cost of simulations, stochastic noise in simulation trajectories and limitations of the available experimental data. The approach is demonstrated on a light scattering trajectory for a human papillomavirus (HPV) in vitro assembly system, showing that the method can provide rate parameters that produce accurate curve fits and are in good concordance with prior analysis of the data. These fits provide an insight into potential assembly mechanisms of the in vitro system and give a basis for exploring how these mechanisms might vary between in vitro and in vivo assembly conditions.

SSME component assembly and life management expert system

NASA Technical Reports Server (NTRS)

Ali, M.; Dietz, W. E.; Ferber, H. J.

1989-01-01

The space shuttle utilizes several rocket engine systems, all of which must function with a high degree of reliability for successful mission completion. The space shuttle main engine (SSME) is by far the most complex of the rocket engine systems and is designed to be reusable. The reusability of spacecraft systems introduces many problems related to testing, reliability, and logistics. Components must be assembled from parts inventories in a manner which will most effectively utilize the available parts. Assembly must be scheduled to efficiently utilize available assembly benches while still maintaining flight schedules. Assembled components must be assigned to as many contiguous flights as possible, to minimize component changes. Each component must undergo a rigorous testing program prior to flight. In addition, testing and assembly of flight engines and components must be done in conjunction with the assembly and testing of developmental engines and components. The development, testing, manufacture, and flight assignments of the engine fleet involves the satisfaction of many logistical and operational requirements, subject to many constraints. The purpose of the SSME Component Assembly and Life Management Expert System (CALMES) is to assist the engine assembly and scheduling process, and to insure that these activities utilize available resources as efficiently as possible.

High-accuracy microassembly by intelligent vision systems and smart sensor integration

NASA Astrophysics Data System (ADS)

Schilp, Johannes; Harfensteller, Mark; Jacob, Dirk; Schilp, Michael

2003-10-01

Innovative production processes and strategies from batch production to high volume scale are playing a decisive role in generating microsystems economically. In particular assembly processes are crucial operations during the production of microsystems. Due to large batch sizes many microsystems can be produced economically by conventional assembly techniques using specialized and highly automated assembly systems. At laboratory stage microsystems are mostly assembled by hand. Between these extremes there is a wide field of small and middle sized batch production wherefore common automated solutions rarely are profitable. For assembly processes at these batch sizes a flexible automated assembly system has been developed at the iwb. It is based on a modular design. Actuators like grippers, dispensers or other process tools can easily be attached due to a special tool changing system. Therefore new joining techniques can easily be implemented. A force-sensor and a vision system are integrated into the tool head. The automated assembly processes are based on different optical sensors and smart actuators like high-accuracy robots or linear-motors. A fiber optic sensor is integrated in the dispensing module to measure contactless the clearance between the dispense needle and the substrate. Robot vision systems using the strategy of optical pattern recognition are also implemented as modules. In combination with relative positioning strategies, an assembly accuracy of the assembly system of less than 3 μm can be realized. A laser system is used for manufacturing processes like soldering.

Instrumentation to Aid in Steel Bridge Fabrication : Bridge Virtual Assembly System

DOT National Transportation Integrated Search

2018-05-01

This pool funded project developed a BRIDGE VIRTUAL ASSEMBLY SYSTEM (BRIDGE VAS) that improves manufacturing processes and enhances quality control for steel bridge fabrication. The system replaces conventional match-drilling with virtual assembly me...

Engine with exhaust gas recirculation system and variable geometry turbocharger

DOEpatents

Keating, Edward J.

2015-11-03

An engine assembly includes an intake assembly, an internal combustion engine defining a plurality of cylinders and configured to combust a fuel and produce exhaust gas, and an exhaust assembly in fluid communication with a first subset of the plurality of cylinders. Each of the plurality of cylinders are provided in fluid communication with the intake assembly. The exhaust assembly is provided in fluid communication with a first subset of the plurality of cylinders, and a dedicated exhaust gas recirculation system in fluid communication with both a second subset of the plurality of cylinders and with the intake assembly. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the second subset of the plurality of cylinders to the intake assembly. Finally, the engine assembly includes a turbocharger having a variable geometry turbine in fluid communication with the exhaust assembly.

Mounting Systems for Structural Members, Fastening Assemblies Thereof, and Vibration Isolation Systems Including the Same

NASA Technical Reports Server (NTRS)

Young, Ken (Inventor); Hindle, Timothy (Inventor); Barber, Tim Daniel (Inventor)

2016-01-01

Mounting systems for structural members, fastening assemblies thereof, and vibration isolation systems including the same are provided. Mounting systems comprise a pair of mounting brackets, each clamped against a fastening assembly forming a mounting assembly. Fastening assemblies comprise a spherical rod end comprising a spherical member having a through opening and an integrally threaded shaft, first and second seating members on opposite sides of the spherical member and each having a through opening that is substantially coaxial with the spherical member through opening, and a partially threaded fastener that threadably engages each mounting bracket forming the mounting assembly. Structural members have axial end portions, each releasably coupled to a mounting bracket by the integrally threaded shaft. Axial end portions are threaded in opposite directions for permitting structural member rotation to adjust a length thereof to a substantially zero strain position. Structural members may be vibration isolator struts in vibration isolation systems.

Semi-Immersive Virtual Turbine Engine Simulation System

NASA Astrophysics Data System (ADS)

Abidi, Mustufa H.; Al-Ahmari, Abdulrahman M.; Ahmad, Ali; Darmoul, Saber; Ameen, Wadea

2018-05-01

The design and verification of assembly operations is essential for planning product production operations. Recently, virtual prototyping has witnessed tremendous progress, and has reached a stage where current environments enable rich and multi-modal interaction between designers and models through stereoscopic visuals, surround sound, and haptic feedback. The benefits of building and using Virtual Reality (VR) models in assembly process verification are discussed in this paper. In this paper, we present the virtual assembly (VA) of an aircraft turbine engine. The assembly parts and sequences are explained using a virtual reality design system. The system enables stereoscopic visuals, surround sounds, and ample and intuitive interaction with developed models. A special software architecture is suggested to describe the assembly parts and assembly sequence in VR. A collision detection mechanism is employed that provides visual feedback to check the interference between components. The system is tested for virtual prototype and assembly sequencing of a turbine engine. We show that the developed system is comprehensive in terms of VR feedback mechanisms, which include visual, auditory, tactile, as well as force feedback. The system is shown to be effective and efficient for validating the design of assembly, part design, and operations planning.

Physical principles for DNA tile self-assembly.

PubMed

Evans, Constantine G; Winfree, Erik

2017-06-19

DNA tiles provide a promising technique for assembling structures with nanoscale resolution through self-assembly by basic interactions rather than top-down assembly of individual structures. Tile systems can be programmed to grow based on logical rules, allowing for a small number of tile types to assemble large, complex assemblies that can retain nanoscale resolution. Such algorithmic systems can even assemble different structures using the same tiles, based on inputs that seed the growth. While programming and theoretical analysis of tile self-assembly often makes use of abstract logical models of growth, experimentally implemented systems are governed by nanoscale physical processes that can lead to very different behavior, more accurately modeled by taking into account the thermodynamics and kinetics of tile attachment and detachment in solution. This review discusses the relationships between more abstract and more physically realistic tile assembly models. A central concern is how consideration of model differences enables the design of tile systems that robustly exhibit the desired abstract behavior in realistic physical models and in experimental implementations. Conversely, we identify situations where self-assembly in abstract models can not be well-approximated by physically realistic models, putting constraints on physical relevance of the abstract models. To facilitate the discussion, we introduce a unified model of tile self-assembly that clarifies the relationships between several well-studied models in the literature. Throughout, we highlight open questions regarding the physical principles for DNA tile self-assembly.

Photovoltaic system with improved AC connections and method of making same

DOEpatents

Cioffi, Philip Michael; Todorovic, Maja Harfman; Herzog, Michael Scott; Korman, Charles Steven; Doherty, Donald M.; Johnson, Neil Anthony

2018-02-13

An alternating current (AC) harness for a photovoltaic (PV) system includes a wire assembly having a first end and a second end, the wire assembly having a plurality of lead wires, and at least one AC connection module positioned at a location along a length of the wire assembly between the first end and the second end. Further, the at least one AC connection module includes a first connection terminal electrically coupled to the plurality of lead wires of the wire assembly and constructed to electrically couple the wire assembly with an output of a first PV module of the PV system. The at least one AC connection module also includes a second connection terminal electrically coupled to the plurality of lead wires of the wire assembly and constructed to electrically couple the wire assembly with an output of a second PV module of the PV system.

Synthesis and assembly of retrovirus Gag precursors into immature capsids in vitro.

PubMed Central

Sakalian, M; Parker, S D; Weldon, R A; Hunter, E

1996-01-01

The assembly of retroviral particles is mediated by the product of the gag gene; no other retroviral gene products are necessary for this process. While most retroviruses assemble their capsids at the plasma membrane, viruses of the type D class preassemble immature capsids within the cytoplasm of infected cells. This has allowed us to determine whether immature capsids of the prototypical type D retrovirus, Mason-Pfizer monkey virus (M-PMV), can assemble in a cell-free protein synthesis system. We report here that assembly of M-PMV Gag precursor proteins can occur in this in vitro system. Synthesized particles sediment in isopycnic gradients to the appropriate density and in thin-section electron micrographs have a size and appearance consistent with those of immature retrovirus capsids. The in vitro system described in this report appears to faithfully mimic the process of assembly which occurs in the host cell cytoplasm, since M-PMV gag mutants defective in in vivo assembly also fail to assemble in vitro. Likewise, the Gag precursor proteins of retroviruses that undergo type C morphogenesis, Rous sarcoma virus and human immunodeficiency virus, which do not preassemble capsids in vivo, fail to assemble particles in this system. Additionally, we demonstrate, with the use of anti-Gag antibodies, that this cell-free system can be utilized for analysis in vitro of potential inhibitors of retrovirus assembly. PMID:8648705

Control assembly for controlling a fuel cell system during shutdown and restart

DOEpatents

Venkataraman, Ramki; Berntsen, George; Carlson, Glenn L.; Farooque, Mohammad; Beachy, Dan; Peterhans, Stefan; Bischoff, Manfred

2010-06-15

A fuel cell system and method in which the fuel cell system receives and an input oxidant gas and an input fuel gas, and in which a fuel processing assembly is provided and is adapted to at least humidify the input fuel gas which is to be supplied to the anode of the fuel cell of the system whose cathode receives the oxidant input gas via an anode oxidizing assembly which is adapted to couple the output of the anode of the fuel cell to the inlet of the cathode of the fuel cell during normal operation, shutdown and restart of the fuel cell system, and in which a control assembly is further provided and is adapted to respond to shutdown of the fuel cell system during which input fuel gas and input oxidant gas cease to be received by the fuel cell system, the control assembly being further adapted to, when the fuel cell system is shut down: control the fuel cell system so as to enable a purging gas to be able to flow through the fuel processing assembly to remove humidified fuel gas from the processing assembly and to enable a purging gas to be able to flow through the anode of the fuel cell.

"Chemical transformers" from nanoparticle ensembles operated with logic.

PubMed

Motornov, Mikhail; Zhou, Jian; Pita, Marcos; Gopishetty, Venkateshwarlu; Tokarev, Ihor; Katz, Evgeny; Minko, Sergiy

2008-09-01

The pH-responsive nanoparticles were coupled with information-processing enzyme-based systems to yield "smart" signal-responsive hybrid systems with built-in Boolean logic. The enzyme systems performed AND/OR logic operations, transducing biochemical input signals into reversible structural changes (signal-directed self-assembly) of the nanoparticle assemblies, thus resulting in the processing and amplification of the biochemical signals. The hybrid system mimics biological systems in effective processing of complex biochemical information, resulting in reversible changes of the self-assembled structures of the nanoparticles. The bioinspired approach to the nanostructured morphing materials could be used in future self-assembled molecular robotic systems.

Application of the Modular Automated Reconfigurable Assembly System (MARAS) concept to adaptable vision gauging and parts feeding

NASA Technical Reports Server (NTRS)

By, Andre Bernard; Caron, Ken; Rothenberg, Michael; Sales, Vic

1994-01-01

This paper presents the first phase results of a collaborative effort between university researchers and a flexible assembly systems integrator to implement a comprehensive modular approach to flexible assembly automation. This approach, named MARAS (Modular Automated Reconfigurable Assembly System), has been structured to support multiple levels of modularity in terms of both physical components and system control functions. The initial focus of the MARAS development has been on parts gauging and feeding operations for cylinder lock assembly. This phase is nearing completion and has resulted in the development of a highly configurable system for vision gauging functions on a wide range of small components (2 mm to 100 mm in size). The reconfigurable concepts implemented in this adaptive Vision Gauging Module (VGM) are now being extended to applicable aspects of the singulating, selecting, and orienting functions required for the flexible feeding of similar mechanical components and assemblies.

Evolving Systems: Adaptive Key Component Control and Inheritance of Passivity and Dissipativity

NASA Technical Reports Server (NTRS)

Frost, S. A.; Balas, M. J.

2010-01-01

We propose a new framework called Evolving Systems to describe the self-assembly, or autonomous assembly, of actively controlled dynamical subsystems into an Evolved System with a higher purpose. Autonomous assembly of large, complex flexible structures in space is a target application for Evolving Systems. A critical requirement for autonomous assembling structures is that they remain stable during and after assembly. The fundamental topic of inheritance of stability, dissipativity, and passivity in Evolving Systems is the primary focus of this research. In this paper, we develop an adaptive key component controller to restore stability in Nonlinear Evolving Systems that would otherwise fail to inherit the stability traits of their components. We provide sufficient conditions for the use of this novel control method and demonstrate its use on an illustrative example.

Fuel injection assembly for use in turbine engines and method of assembling same

DOEpatents

Uhm, Jong Ho; Johnson, Thomas Edward

2015-03-24

A fuel injection assembly for use in a turbine engine is provided. The fuel injection assembly includes a plurality of tube assemblies, wherein each of the tube assemblies includes an upstream portion and a downstream portion. Each tube assembly includes a plurality of tubes that extend from the upstream portion to the downstream portion or from the upstream portion through the downstream portion. At least one injection system is coupled to at least one tube assembly of the plurality of tube assemblies. The injection system includes a fluid supply member that extends from a fluid source to the downstream portion of the tube assembly. The fluid supply member includes a first end portion located in the downstream portion of the tube assembly, wherein the first end portion has at least one first opening for channeling fluid through the tube assembly to facilitate reducing a temperature therein.

Research on multi - channel interactive virtual assembly system for power equipment under the “VR+” era

NASA Astrophysics Data System (ADS)

Ren, Yilong; Duan, Xitong; Wu, Lei; He, Jin; Xu, Wu

2017-06-01

With the development of the “VR+” era, the traditional virtual assembly system of power equipment has been unable to satisfy our growing needs. In this paper, based on the analysis of the traditional virtual assembly system of electric power equipment and the application of VR technology in the virtual assembly system of electric power equipment in our country, this paper puts forward the scheme of establishing the virtual assembly system of power equipment: At first, we should obtain the information of power equipment, then we should using OpenGL and multi texture technology to build 3D solid graphics library. After the completion of three-dimensional modeling, we can use the dynamic link library DLL package three-dimensional solid graphics generation program to realize the modularization of power equipment model library and power equipment model library generated hidden algorithm. After the establishment of 3D power equipment model database, we set up the virtual assembly system of 3D power equipment to separate the assembly operation of the power equipment from the space. At the same time, aiming at the deficiency of the traditional gesture recognition algorithm, we propose a gesture recognition algorithm based on improved PSO algorithm for BP neural network data glove. Finally, the virtual assembly system of power equipment can really achieve multi-channel interaction function.

Multi-Robot Assembly Strategies and Metrics.

PubMed

Marvel, Jeremy A; Bostelman, Roger; Falco, Joe

2018-02-01

We present a survey of multi-robot assembly applications and methods and describe trends and general insights into the multi-robot assembly problem for industrial applications. We focus on fixtureless assembly strategies featuring two or more robotic systems. Such robotic systems include industrial robot arms, dexterous robotic hands, and autonomous mobile platforms, such as automated guided vehicles. In this survey, we identify the types of assemblies that are enabled by utilizing multiple robots, the algorithms that synchronize the motions of the robots to complete the assembly operations, and the metrics used to assess the quality and performance of the assemblies.

Multi-Robot Assembly Strategies and Metrics

PubMed Central

MARVEL, JEREMY A.; BOSTELMAN, ROGER; FALCO, JOE

2018-01-01

We present a survey of multi-robot assembly applications and methods and describe trends and general insights into the multi-robot assembly problem for industrial applications. We focus on fixtureless assembly strategies featuring two or more robotic systems. Such robotic systems include industrial robot arms, dexterous robotic hands, and autonomous mobile platforms, such as automated guided vehicles. In this survey, we identify the types of assemblies that are enabled by utilizing multiple robots, the algorithms that synchronize the motions of the robots to complete the assembly operations, and the metrics used to assess the quality and performance of the assemblies. PMID:29497234

Biocatalytic Self-Assembly on Magnetic Nanoparticles.

PubMed

Conte, Maria P; Sahoo, Jugal Kishore; Abul-Haija, Yousef M; Lau, K H Aaron; Ulijn, Rein V

2018-01-24

Combining (bio)catalysis and molecular self-assembly provides an effective approach for the production and processing of self-assembled materials by exploiting catalysis to direct the assembly kinetics and hence controlling the formation of ordered nanostructures. Applications of (bio)catalytic self-assembly in biologically interfacing systems and in nanofabrication have recently been reported. Inspired by self-assembly in biological cells, efforts to confine catalysts on flat or patterned surfaces to exert spatial control over molecular gelator generation and nanostructure self-assembly have also emerged. Building on our previous work in the area, we demonstrate in this report the use of enzymes immobilized onto magnetic nanoparticles (NPs) to spatially localize the initiation of peptide self-assembly into nanofibers around NPs. The concept is generalized for both an equilibrium biocatalytic system that forms stable hydrogels and a nonequilibrium system that normally has a preset lifetime. Characterization of the hydrogels shows that self-assembly occurs at the site of enzyme immobilization on the NPs to give rise to gels with a "hub-and-spoke" morphology, where the nanofibers are linked through the enzyme-NP conjugates. This NP-controlled arrangement of self-assembled nanofibers enables both remarkable enhancements in the shear strength of hydrogel systems and a dramatic extension of the hydrogel stability in the nonequilibrium system. We are also able to show that the use of magnetic NPs enables the external control of both the formation of the hydrogel and its overall structure by application of an external magnetic field. We anticipate that the enhanced properties and stimuli-responsiveness of our NP-enzyme system will have applications ranging from nanomaterial fabrication to biomaterials and biosensing.

Fluidic self-actuating control assembly

DOEpatents

Grantz, Alan L.

1979-01-01

A fluidic self-actuating control assembly for use in a reactor wherein no external control inputs are required to actuate (scram) the system. The assembly is constructed to scram upon sensing either a sudden depressurization of reactor inlet flow or a sudden increase in core neutron flux. A fluidic control system senses abnormal flow or neutron flux transients and actuates the system, whereupon assembly coolant flow reverses, forcing absorber balls into the reactor core region.

75 FR 4265 - Airworthiness Directives; Lifesavings Systems Corp., D-Lok Hook Assembly

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-27

... Airworthiness Directives; Lifesavings Systems Corp., D-Lok Hook Assembly AGENCY: Federal Aviation Administration... adopting a new airworthiness directive (AD) for the Lifesavings Systems Corp., D-Lok Hook assembly... reported surface irregularities and discontinuities on certain D-Lok Hooks because of an unapproved change...

Combustion pinhole-camera system

DOEpatents

Witte, A.B.

1982-05-19

A pinhole camera system is described utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor.

Combustion pinhole camera system

DOEpatents

Witte, A.B.

1984-02-21

A pinhole camera system is described utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor. 2 figs.

Combustion pinhole camera system

DOEpatents

Witte, Arvel B.

1984-02-21

A pinhole camera system utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor.

Fertility disturbances of dimethylacetamide and glycerol in rooster sperm diluents: Discrimination among effects produced pre and post freezing-thawing process.

PubMed

Abouelezz, F M K; Sayed, M A M; Santiago-Moreno, J

2017-09-01

With avian sperm cryopreservation protocols, the most widely used cryoprotectants (CPAs) are the glycerol (GLY; in gradual freezing: in-straw freezing method), and the dimethylacetamide (DMA; in pellets by plunging into liquid nitrogen: in-pellet rapid freezing method). Use of both methods results in a small portion of thawed live sperm with lesser fertilizing ability compared with the semen samples immediately after collection. This study was conducted to assess the pre-freezing damage occurring to the sperm due to the interaction with the cryoprotectants (CPAs) GLY (8%) and DMA (5%), as well as the post-freezing damage resulting from both freezing methods Data for each treatment, in fresh and frozen-thawed samples, were compared for sperm motility, fertilizing capacity and sperm-egg penetration holes/germinal disc (SP holes/GD). Hens (n=50) were artificially inseminated (10 hens/treatment) six times with 3day intervals between inseminations. The treatment of fresh sperm with DMA led to a reduction (P<0.05) in the count of SP holes/GD (21.4) and the fertility rate (66.7%). The addition and elimination of GLY in fresh samples resulted in a lesser (P<0.05) number of SP holes/GD (11.8) and the fertility rate (i.e., 50.0%). The number of SP-holes/GD was least in frozen-thawed samples using both DMA and GLY (14.2 and 9.2, respectively). The fertility rate when using semen frozen with DMA in- pellets was greater (P<0.05) than with use of semen that had been frozen using GLY in straws (46.4% compared with 31.3%). The reduction in fertility compared with the control when semen was cryopreserved using GLY was 64.1%; the GLY addition and elimination was responsible for two thirds of this reduction. The reduction in fertility when using semen cryopreserved with DMA was 46.7%; half of the reduction was attributed to the treatment with DMA. In conclusion, the mechanical damage attributed to the process for reducing GLY concentrations was more harmful to sperm fertilizing capacity than the toxicity of DMA and freeze/thaw process. For both freezing methods, the amount of sperm cryo-damage was similar, when the damage attributed to the CPA addition and elimination process was excluded. Copyright © 2017 Elsevier B.V. All rights reserved.

Optimization of a vitrification protocol for hatched blastocysts from the dromedary camel (Camelus dromedarius).

PubMed

Herrid, M; Billah, M; Malo, C; Skidmore, J A

2016-03-01

The objective of this study was to modify and optimize a vitrification protocol (open pulled straw) that was originally designed for human oocytes and embryos, to make it suitable for the cryopreservation of camel hatched blastocysts. The original open pulled straw protocol was a complex process with 15-minute exposure of oocytes/embryos in 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (Me2SO) for equilibration, and cooling in 16% EG + 16% Me2SO + 1 M sucrose. Recognizing a need to better control the cryoprotectant (CPA) concentrations, while avoiding toxicity to the embryos, the effects on the survival rate and developmental potential of camel embryos in vitro were investigated using two different methods of loading the CPAs into the embryos (stepwise and semicontinuous increase in concentration), two different loading temperature/time (room temperature ∼24 °C/15 min and body 37 °C/3 min), and the replacement of Me2SO with EG alone or in combination with glycerol (Gly). A total of 145 in vivo-derived embryos were subjected to these processes, and after warming their morphological quality and integrity, and re-expansion was assessed after 0, 2, 24, 48, 72, and 96 hours of culture. Exposure of embryos in a stepwise method was more beneficial to the survival of embryos than was the semicontinuous process, and loading of CPAs at 37 °C with a short exposure time (3 minutes) resulted in an outcome comparable to the original processing at room temperature with a longer exposure time (15 minutes). The replacement of the Me2SO + EG mixture with EG only or a combination of EG + Gly in the vitrification medium significantly improved the outcome of all these evaluation criteria (P < 0.05). The modified protocol of loading EG at 37 °C for 3 minutes has increased the embryo survival of the original protocol from 67% to 91% and the developmental rate from 57% to 83% at 5-day culture. These results were comparable to or better than those reported in human or other species, indicating that this optimized method is well suited to any commercial embryo transfer program in the dromedary camel. Copyright © 2016 Elsevier Inc. All rights reserved.

Particular adaptations to potentially slippery surfaces: the effects of friction on consecutive postural adjustments (CPA).

PubMed

Memari, Sahel; Le Bozec, Serge; Bouisset, Simon

2014-02-21

This research deals with the postural adjustments that occur after the end of voluntary movement ("consecutive postural adjustments": CPAs). The influence of a potentially slippery surface on CPA characteristics was considered, with the aim of exploring more deeply the postural component of the task-movement. Seven male adults were asked to perform a single step, as quickly as possible, to their own footprint marked on the ground. A force plate measured the resultant reaction forces along the antero-posterior axis (R(x)) and the centre of pressure (COP) displacements along the antero-posterior and lateral axes (Xp and Yp). The velocity of the centre of gravity (COG) along the antero-posterior axis and the corresponding impulse (∫R(x)dt) were calculated; the peak velocity (termed "progression velocity": V(xG)) was measured. The required coefficient of friction (RCOF) along the progression axis (pμ(x)) was determined. Two materials, differing by their COF, were laid at foot contact (FC), providing a rough foot contact (RoFC), and a smooth foot contact (SmFC) considered to be potentially slippery. Two step lengths were also performed: a short step (SS) and a long step (LS). Finally, the subjects completed four series of ten steps each. These were preceded by preliminary trials, to allow them to acquire the necessary adaptation to experimental conditions. The antero-posterior force time course presented a positive phase, that included APAs ("anticipatory postural adjustments") and step execution (STEP), followed by a negative one, corresponding to CPAs. The backward impulse (CPI) was equal to the forward one (BPI), independently of friction and progression velocity. Moreover, V(xG) did not differ according to friction, but was faster when the step length was greater. Last CPA peak amplitudes (pCPA) were significantly greater and CPA durations (dCPA) shorter for RoFC and conversely for SmFC, contrary to APA. Finally, the results show a particular adaptation to the potentially slippery surface (SmFC). They suggest that adherence modulation at foot contact could be one of the rules for controlling COG displacement in single stepping. Consequently, the actual coefficient of friction value might be implemented in the motor programme at a higher level than the voluntary movement specific parameters. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

An expert system executive for automated assembly of large space truss structures

NASA Technical Reports Server (NTRS)

Allen, Cheryl L.

1993-01-01

Langley Research Center developed a unique test bed for investigating the practical problems associated with the assembly of large space truss structures using robotic manipulators. The test bed is the result of an interdisciplinary effort that encompasses the full spectrum of assembly problems - from the design of mechanisms to the development of software. The automated structures assembly test bed and its operation are described, the expert system executive and its development are detailed, and the planned system evolution is discussed. Emphasis is on the expert system implementation of the program executive. The executive program must direct and reliably perform complex assembly tasks with the flexibility to recover from realistic system errors. The employment of an expert system permits information that pertains to the operation of the system to be encapsulated concisely within a knowledge base. This consolidation substantially reduced code, increased flexibility, eased software upgrades, and realized a savings in software maintenance costs.

SpRoUTS (Space Robot Universal Truss System): Reversible Robotic Assembly of Deployable Truss Structures of Reconfigurable Length

NASA Technical Reports Server (NTRS)

Jenett, Benjamin; Cellucci, Daniel; Cheung, Kenneth

2015-01-01

Automatic deployment of structures has been a focus of much academic and industrial work on infrastructure applications and robotics in general. This paper presents a robotic truss assembler designed for space applications - the Space Robot Universal Truss System (SpRoUTS) - that reversibly assembles a truss from a feedstock of hinged andflat-packed components, by folding the sides of each component up and locking onto the assembled structure. We describe the design and implementation of the robot and show that the assembled truss compares favorably with prior truss deployment systems.

A Gimbal sizing analysis for an IPACS rotating assembly

NASA Technical Reports Server (NTRS)

Burke, P. R.; Coronato, P. A.

1985-01-01

All major components of an integrated power/attitude control system (IPACS) assembly were analyzed for testing, launch, and operational stresses. The conceptual design for the outer gimbal and mounting ring structures were developed and analyzed along with preliminary designs of the pivot and torquer assemblies. Results from the system response analysis and the thermal analysis are also presented. Gimballing of this rotating assembly should present few difficulties as the maximum gimballing rate is quite low. However, the inner gimbal assembly in its current configuration must be modified to develop the system from a laboratory concept to a realistic flight hardware status.

System and method for incremental forming

DOEpatents

Beltran, Michael; Cao, Jian; Roth, John T.

2015-12-29

A system includes a frame configured to hold a workpiece and first and second tool positioning assemblies configured to be opposed to each other on opposite sides of the workpiece. The first and second tool positioning assemblies each include a toolholder configured to secure a tool to the tool positioning assembly, a first axis assembly, a second axis assembly, and a third axis assembly. The first, second, and third axis assemblies are each configured to articulate the toolholder along a respective axis. Each axis assembly includes first and second guides extending generally parallel to the corresponding axis and disposed on opposing sides of the toolholder with respect to the corresponding axis. Each axis assembly includes first and second carriages articulable along the first and second guides of the axis assembly, respectively, in the direction of the corresponding axis.

Low-impact mating system

NASA Technical Reports Server (NTRS)

Lewis, James L. (Inventor); Carroll, Monty B. (Inventor); Le, Thang D. (Inventor); Morales, Ray H. (Inventor); Robertson, Brandan R. (Inventor)

2009-01-01

An androgynous mating system for mating two exoatmospheric space modules comprising a first mating assembly capable of mating with a second mating assembly; a second mating assembly structurally identical to said first mating assembly, said first mating assembly comprising; a load ring; a plurality of load cell subassemblies; a plurality of actuators; a base ring; a tunnel; a closed loop control system; one or more electromagnets; and one or more striker plates, wherein said one or more electomagnets on said second mating assembly are capable of mating with said one or more striker plates on said first mating assembly, and wherein said one or more striker plates is comprised of a plate of predetermined shape and a 5-DOF mechanism capable of maintaining predetermined contact requirements during said mating of said one or more electromagnets and said one or more striker plates.

Virtualization for Cost-Effective Teaching of Assembly Language Programming

ERIC Educational Resources Information Center

Cadenas, José O.; Sherratt, R. Simon; Howlett, Des; Guy, Chris G.; Lundqvist, Karsten O.

2015-01-01

This paper describes a virtual system that emulates an ARM-based processor machine, created to replace a traditional hardware-based system for teaching assembly language. The virtual system proposed here integrates, in a single environment, all the development tools necessary to deliver introductory or advanced courses on modern assembly language…

Electromagnetic compatibility test report for the tethered satellite data acquisition and control assembly

NASA Astrophysics Data System (ADS)

Hoskins, Douglas; Snead, Robert

1988-05-01

This report details the results of an electromagnetic compatibility test on the SCI Systems Data Acquisition and Control Assembly (DACA). This assembly is an electronic processor which controls the central communication link from the Tethered Satellite System (TSS) to the Space Transportation System Orbiter Space Shuttle.

Digital Material Assembly by Passive Means and Modular Isotropic Lattice Extruder System

NASA Technical Reports Server (NTRS)

Gershenfeld, Neil (Inventor); Carney, Matthew Eli (Inventor); Jenett, Benjamin (Inventor)

2017-01-01

A set of machines and related systems build structures by the additive assembly of discrete parts. These digital material assemblies constrain the constituent parts to a discrete set of possible positions and orientations. In doing so, the structures exhibit many of the properties inherent in digital communication such as error correction, fault tolerance and allow the assembly of precise structures with comparatively imprecise tools. Assembly of discrete cellular lattices by a Modular Isotropic Lattice Extruder System (MILES) is implemented by pulling strings of lattice elements through a forming die that enforces geometry constraints that lock the elements into a rigid structure that can then be pushed against and extruded out of the die as an assembled, loadbearing structure.

Research study entitled advanced X-ray astrophysical observatory (AXAF). [system engineering for a total X-ray telescope assembly

NASA Technical Reports Server (NTRS)

Rasche, R. W.

1979-01-01

General background and overview material are presented along with data from studies performed to determine the sensitivity, feasibility, and required performance of systems for a total X-ray telescope assembly. Topics covered include: optical design, mirror support concepts, mirror weight estimates, the effects of l g on mirror elements, mirror assembly resonant frequencies, optical bench considerations, temperature control of the mirror assembly, and the aspect determination system.

Electron beam diagnostic for profiling high power beams

DOEpatents

Elmer, John W [Danville, CA; Palmer, Todd A [Livermore, CA; Teruya, Alan T [Livermore, CA

2008-03-25

A system for characterizing high power electron beams at power levels of 10 kW and above is described. This system is comprised of a slit disk assembly having a multitude of radial slits, a conducting disk with the same number of radial slits located below the slit disk assembly, a Faraday cup assembly located below the conducting disk, and a start-stop target located proximate the slit disk assembly. In order to keep the system from over-heating during use, a heat sink is placed in close proximity to the components discussed above, and an active cooling system, using water, for example, can be integrated into the heat sink. During use, the high power beam is initially directed onto a start-stop target and after reaching its full power is translated around the slit disk assembly, wherein the beam enters the radial slits and the conducting disk radial slits and is detected at the Faraday cup assembly. A trigger probe assembly can also be integrated into the system in order to aid in the determination of the proper orientation of the beam during reconstruction. After passing over each of the slits, the beam is then rapidly translated back to the start-stop target to minimize the amount of time that the high power beam comes in contact with the slit disk assembly. The data obtained by the system is then transferred into a computer system, where a computer tomography algorithm is used to reconstruct the power density distribution of the beam.

A System for the Automatic Assembly of Test Questions Using a No-SQL Database

ERIC Educational Resources Information Center

Shin, Sanggyu; Hashimoto, Hiroshi

2014-01-01

We describe a system that automatically assembles test questions from a set of examples. Our system can create test questions appropriate for each user's level at low cost. In particular, when a user review their lesson, our system provides new test questions which are assembled based on their previous test results and past mistakes, rather than a…

Dynamic and programmable self-assembly of micro-rafts at the air-water interface

PubMed Central

Wang, Wendong; Giltinan, Joshua; Zakharchenko, Svetlana; Sitti, Metin

2017-01-01

Dynamic self-assembled material systems constantly consume energy to maintain their spatiotemporal structures and functions. Programmable self-assembly translates information from individual parts to the collective whole. Combining dynamic and programmable self-assembly in a single platform opens up the possibilities to investigate both types of self-assembly simultaneously and to explore their synergy. This task is challenging because of the difficulty in finding suitable interactions that are both dissipative and programmable. We present a dynamic and programmable self-assembling material system consisting of spinning at the air-water interface circular magnetic micro-rafts of radius 50 μm and with cosinusoidal edge-height profiles. The cosinusoidal edge-height profiles not only create a net dissipative capillary repulsion that is sustained by continuous torque input but also enable directional assembly of micro-rafts. We uncover the layered arrangement of micro-rafts in the patterns formed by dynamic self-assembly and offer mechanistic insights through a physical model and geometric analysis. Furthermore, we demonstrate programmable self-assembly and show that a 4-fold rotational symmetry encoded in individual micro-rafts translates into 90° bending angles and square-based tiling in the assembled structures of micro-rafts. We anticipate that our dynamic and programmable material system will serve as a model system for studying nonequilibrium dynamics and statistical mechanics in the future. PMID:28560332

Dynamic and programmable self-assembly of micro-rafts at the air-water interface.

PubMed

Wang, Wendong; Giltinan, Joshua; Zakharchenko, Svetlana; Sitti, Metin

2017-05-01

Dynamic self-assembled material systems constantly consume energy to maintain their spatiotemporal structures and functions. Programmable self-assembly translates information from individual parts to the collective whole. Combining dynamic and programmable self-assembly in a single platform opens up the possibilities to investigate both types of self-assembly simultaneously and to explore their synergy. This task is challenging because of the difficulty in finding suitable interactions that are both dissipative and programmable. We present a dynamic and programmable self-assembling material system consisting of spinning at the air-water interface circular magnetic micro-rafts of radius 50 μm and with cosinusoidal edge-height profiles. The cosinusoidal edge-height profiles not only create a net dissipative capillary repulsion that is sustained by continuous torque input but also enable directional assembly of micro-rafts. We uncover the layered arrangement of micro-rafts in the patterns formed by dynamic self-assembly and offer mechanistic insights through a physical model and geometric analysis. Furthermore, we demonstrate programmable self-assembly and show that a 4-fold rotational symmetry encoded in individual micro-rafts translates into 90° bending angles and square-based tiling in the assembled structures of micro-rafts. We anticipate that our dynamic and programmable material system will serve as a model system for studying nonequilibrium dynamics and statistical mechanics in the future.

Capability 9.3 Assembly and Deployment

NASA Technical Reports Server (NTRS)

Dorsey, John

2005-01-01

Large space systems are required for a range of operational, commercial and scientific missions objectives however, current launch vehicle capacities substantially limit the size of space systems (on-orbit or planetary). Assembly and Deployment is the process of constructing a spacecraft or system from modules which may in turn have been constructed from sub-modules in a hierarchical fashion. In-situ assembly of space exploration vehicles and systems will require a broad range of operational capabilities, including: Component transfer and storage, fluid handling, construction and assembly, test and verification. Efficient execution of these functions will require supporting infrastructure, that can: Receive, store and protect (materials, components, etc.); hold and secure; position, align and control; deploy; connect/disconnect; construct; join; assemble/disassemble; dock/undock; and mate/demate.

Precision lens assembly with alignment turning system

NASA Astrophysics Data System (ADS)

Ho, Cheng-Fang; Huang, Chien-Yao; Lin, Yi-Hao; Kuo, Hui-Jean; Kuo, Ching-Hsiang; Hsu, Wei-Yao; Chen, Fong-Zhi

2017-10-01

The poker chip assembly with high precision lens barrels is widely applied to ultra-high performance optical system. ITRC applies the poker chip assembly technology to the high numerical aperture objective lenses and lithography projection lenses because of its high efficiency assembly process. In order to achieve high precision lens cell for poker chip assembly, an alignment turning system (ATS) is developed. The ATS includes measurement, alignment and turning modules. The measurement module is equipped with a non-contact displacement sensor (NCDS) and an autocollimator (ACM). The NCDS and ACM are used to measure centration errors of the top and the bottom surface of a lens respectively; then the amount of adjustment of displacement and tilt with respect to the rotational axis of the turning machine for the alignment module can be determined. After measurement, alignment and turning processes on the ATS, the centration error of a lens cell with 200 mm in diameter can be controlled within 10 arcsec. Furthermore, a poker chip assembly lens cell with three sub-cells is demonstrated, each sub-cells are measured and accomplished with alignment and turning processes. The lens assembly test for five times by each three technicians; the average transmission centration error of assembly lens is 12.45 arcsec. The results show that ATS can achieve high assembly efficiency for precision optical systems.

Free-floating dual-arm robots for space assembly

NASA Technical Reports Server (NTRS)

Agrawal, Sunil Kumar; Chen, M. Y.

1994-01-01

Freely moving systems in space conserve linear and angular momentum. As moving systems collide, the velocities get altered due to transfer of momentum. The development of strategies for assembly in a free-floating work environment requires a good understanding of primitives such as self motion of the robot, propulsion of the robot due to onboard thrusters, docking of the robot, retrieval of an object from a collection of objects, and release of an object in an object pool. The analytics of such assemblies involve not only kinematics and rigid body dynamics but also collision and impact dynamics of multibody systems. In an effort to understand such assemblies in zero gravity space environment, we are currently developing at Ohio University a free-floating assembly facility with a dual-arm planar robot equipped with thrusters, a free-floating material table, and a free-floating assembly table. The objective is to pick up workpieces from the material table and combine them into prespecified assemblies. This paper presents analytical models of assembly primitives and strategies for overall assembly. A computer simulation of an assembly is developed using the analytical models. The experiment facility will be used to verify the theoretical predictions.

75 FR 3141 - Airworthiness Directives; AVOX Systems and B/E Aerospace Oxygen Cylinder Assemblies, as Installed...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-20

... Airworthiness Directives; AVOX Systems and B/E Aerospace Oxygen Cylinder Assemblies, as Installed on Various... directive (AD), which applies to certain AVOX Systems and B/E Aerospace oxygen cylinder assemblies, as installed on various transport airplanes. That AD currently requires removing certain oxygen cylinder...

21 CFR 1020.30 - Diagnostic x-ray systems and their major components.

Code of Federal Regulations, 2012 CFR

2012-04-01

... irradiation. Diagnostic source assembly means the tube housing assembly with a beam-limiting device attached. Diagnostic x-ray system means an x-ray system designed for irradiation of any part of the human body for the... diagnostic source assembly. Fluoroscopic irradiation time means the cumulative duration during an examination...

21 CFR 1020.30 - Diagnostic x-ray systems and their major components.

Code of Federal Regulations, 2013 CFR

2013-04-01

... irradiation. Diagnostic source assembly means the tube housing assembly with a beam-limiting device attached. Diagnostic x-ray system means an x-ray system designed for irradiation of any part of the human body for the... diagnostic source assembly. Fluoroscopic irradiation time means the cumulative duration during an examination...

21 CFR 1020.30 - Diagnostic x-ray systems and their major components.

Code of Federal Regulations, 2014 CFR

2014-04-01

... irradiation. Diagnostic source assembly means the tube housing assembly with a beam-limiting device attached. Diagnostic x-ray system means an x-ray system designed for irradiation of any part of the human body for the... diagnostic source assembly. Fluoroscopic irradiation time means the cumulative duration during an examination...

Structural Polymorphism in a Self-Assembled Tri-Aromatic Peptide System.

PubMed

Brown, Noam; Lei, Jiangtao; Zhan, Chendi; Shimon, Linda J W; Adler-Abramovich, Lihi; Wei, Guanghong; Gazit, Ehud

2018-04-24

Self-assembly is a process of key importance in natural systems and in nanotechnology. Peptides are attractive building blocks due to their relative facile synthesis, biocompatibility, and other unique properties. Diphenylalanine (FF) and its derivatives are known to form nanostructures of various architectures and interesting and varied characteristics. The larger triphenylalanine peptide (FFF) was found to self-assemble as efficiently as FF, forming related but distinct architectures of plate-like and spherical nanostructures. Here, to understand the effect of triaromatic systems on the self-assembly process, we examined carboxybenzyl-protected diphenylalanine (z-FF) as a minimal model for such an arrangement. We explored different self-assembly conditions by changing solvent compositions and peptide concentrations, generating a phase diagram for the assemblies. We discovered that z-FF can form a variety of structures, including nanowires, fibers, nanospheres, and nanotoroids, the latter were previously observed only in considerably larger or co-assembly systems. Secondary structure analysis revealed that all assemblies possessed a β-sheet conformation. Additionally, in solvent combinations with high water ratios, z-FF formed rigid and self-healing hydrogels. X-ray crystallography revealed a "wishbone" structure, in which z-FF dimers are linked by hydrogen bonds mediated by methanol molecules, with a 2-fold screw symmetry along the c-axis. All-atom molecular dynamics (MD) simulations revealed conformations similar to the crystal structure. Coarse-grained MD simulated the assembly of the peptide into either fibers or spheres in different solvent systems, consistent with the experimental results. This work thus expands the building block library for the fabrication of nanostructures by peptide self-assembly.

High accuracy thermal conductivity measurement of aqueous cryoprotective agents and semi-rigid biological tissues using a microfabricated thermal sensor

PubMed Central

Liang, Xin M.; Sekar, Praveen K.; Zhao, Gang; Zhou, Xiaoming; Shu, Zhiquan; Huang, Zhongping; Ding, Weiping; Zhang, Qingchuan; Gao, Dayong

2015-01-01

An improved thermal-needle approach for accurate and fast measurement of thermal conductivity of aqueous and soft biomaterials was developed using microfabricated thermal conductivity sensors. This microscopic measuring device was comprehensively characterized at temperatures from 0 °C to 40 °C. Despite the previous belief, system calibration constant was observed to be highly temperature-dependent. Dynamic thermal conductivity response during cooling (40 °C to –40 °C) was observed using the miniaturized single tip sensor for various concentrations of CPAs, i.e., glycerol, ethylene glycol and dimethyl sulfoxide. Chicken breast, chicken skin, porcine limb, and bovine liver were assayed to investigate the effect of anatomical heterogeneity on thermal conductivity using the arrayed multi-tip sensor at 20 °C. Experimental results revealed distinctive differences in localized thermal conductivity, which suggests the use of approximated or constant property values is expected to bring about results with largely inflated uncertainties when investigating bio-heat transfer mechanisms and/or performing sophisticated thermal modeling with complex biological tissues. Overall, the presented micro thermal sensor with automated data analysis algorithm is a promising approach for direct thermal conductivity measurement of aqueous solutions and soft biomaterials and is of great value to cryopreservation of tissues, hyperthermia or cryogenic, and other thermal-based clinical diagnostics and treatments. PMID:25993037

High accuracy thermal conductivity measurement of aqueous cryoprotective agents and semi-rigid biological tissues using a microfabricated thermal sensor

NASA Astrophysics Data System (ADS)

Liang, Xin M.; Sekar, Praveen K.; Zhao, Gang; Zhou, Xiaoming; Shu, Zhiquan; Huang, Zhongping; Ding, Weiping; Zhang, Qingchuan; Gao, Dayong

2015-05-01

An improved thermal-needle approach for accurate and fast measurement of thermal conductivity of aqueous and soft biomaterials was developed using microfabricated thermal conductivity sensors. This microscopic measuring device was comprehensively characterized at temperatures from 0 °C to 40 °C. Despite the previous belief, system calibration constant was observed to be highly temperature-dependent. Dynamic thermal conductivity response during cooling (40 °C to -40 °C) was observed using the miniaturized single tip sensor for various concentrations of CPAs, i.e., glycerol, ethylene glycol and dimethyl sulfoxide. Chicken breast, chicken skin, porcine limb, and bovine liver were assayed to investigate the effect of anatomical heterogeneity on thermal conductivity using the arrayed multi-tip sensor at 20 °C. Experimental results revealed distinctive differences in localized thermal conductivity, which suggests the use of approximated or constant property values is expected to bring about results with largely inflated uncertainties when investigating bio-heat transfer mechanisms and/or performing sophisticated thermal modeling with complex biological tissues. Overall, the presented micro thermal sensor with automated data analysis algorithm is a promising approach for direct thermal conductivity measurement of aqueous solutions and soft biomaterials and is of great value to cryopreservation of tissues, hyperthermia or cryogenic, and other thermal-based clinical diagnostics and treatments.

Shuttle APS propellant thermal conditioner study

NASA Technical Reports Server (NTRS)

Pearson, W. E.

1971-01-01

A study program was performed to allow selection of thermal conditioner assemblies for superheating O2 and H2 at supercritical pressures. The application was the auxiliary propulsion system (APS) for the space shuttle vehicle. The O2/H2 APS propellant feed system included propellant conditioners, of which the thermal conditioner assemblies were a part. Cryogens, pumped to pressures above critical, were directed to the thermal conditioner assembly included: (1) a gas generator assembly with ignition system and bipropellant valves, which burned superheated O2 and H2 at rich conditions; (2) a heat exchanger assembly for thermal conditioning of the cryogenic propellant; and (3) a dump nozzle for heat exchanger exhaust.

Assembly of Customized TAL Effectors Through Advanced ULtiMATE System.

PubMed

Yang, Junjiao; Guo, Shengjie; Yuan, Pengfei; Wei, Wensheng

2016-01-01

Transcription activator-like effectors (TALEs) have been widely applied in gene targeting. Here we describe an advanced ULtiMATE (USER-based Ligation-Mediated Assembly of TAL Effector) system that utilizes USER fusion technique and archive of 512 tetramer templates to achieve highly efficient construction of TALEs, which takes only half a day to accomplish the assembly of any given TALE construct. This system is also suitable for large-scale assembly of TALENs and any other TALE-based constructions.

Status of the Node 3 Regenerative Environmental Cpntrol& Life Support System Water Recovery & Oxygen Generation Systems

NASA Technical Reports Server (NTRS)

Carrasquillo, Robyn L.

2003-01-01

NASA s Marshall Space Flight Center is providing three racks containing regenerative water recovery and oxygen generation systems (WRS and OGS) for flight on the lnternational Space Station s (ISS) Node 3 element. The major assemblies included in these racks are the Water Processor Assembly (WPA), Urine Processor Assembly (UPA), Oxygen Generation Assembly (OGA), and the Power Supply Module (PSM) supporting the OGA. The WPA and OGA are provided by Hamilton Sundstrand Space Systems lnternational (HSSSI), while the UPA and PSM are being designed and manufactured in-house by MSFC. The assemblies are currently in the manufacturing and test phase and are to be completed and integrated into flight racks this year. This paper gives an overview of the technologies and system designs, technical challenges encountered and solved, and the current status.

Analytical optimal controls for the state constrained addition and removal of cryoprotective agents

PubMed Central

Chicone, Carmen C.; Critser, John K.

2014-01-01

Cryobiology is a field with enormous scientific, financial and even cultural impact. Successful cryopreservation of cells and tissues depends on the equilibration of these materials with high concentrations of permeating chemicals (CPAs) such as glycerol or 1,2 propylene glycol. Because cells and tissues are exposed to highly anisosmotic conditions, the resulting gradients cause large volume fluctuations that have been shown to damage cells and tissues. On the other hand, there is evidence that toxicity to these high levels of chemicals is time dependent, and therefore it is ideal to minimize exposure time as well. Because solute and solvent flux is governed by a system of ordinary differential equations, CPA addition and removal from cells is an ideal context for the application of optimal control theory. Recently, we presented a mathematical synthesis of the optimal controls for the ODE system commonly used in cryobiology in the absence of state constraints and showed that controls defined by this synthesis were optimal. Here we define the appropriate model, analytically extend the previous theory to one encompassing state constraints, and as an example apply this to the critical and clinically important cell type of human oocytes, where current methodologies are either difficult to implement or have very limited success rates. We show that an enormous increase in equilibration efficiency can be achieved under the new protocols when compared to classic protocols, potentially allowing a greatly increased survival rate for human oocytes, and pointing to a direction for the cryopreservation of many other cell types. PMID:22527943

Self-optimizing approach for automated laser resonator alignment

NASA Astrophysics Data System (ADS)

Brecher, C.; Schmitt, R.; Loosen, P.; Guerrero, V.; Pyschny, N.; Pavim, A.; Gatej, A.

2012-02-01

Nowadays, the assembly of laser systems is dominated by manual operations, involving elaborate alignment by means of adjustable mountings. From a competition perspective, the most challenging problem in laser source manufacturing is price pressure, a result of cost competition exerted mainly from Asia. From an economical point of view, an automated assembly of laser systems defines a better approach to produce more reliable units at lower cost. However, the step from today's manual solutions towards an automated assembly requires parallel developments regarding product design, automation equipment and assembly processes. This paper introduces briefly the idea of self-optimizing technical systems as a new approach towards highly flexible automation. Technically, the work focuses on the precision assembly of laser resonators, which is one of the final and most crucial assembly steps in terms of beam quality and laser power. The paper presents a new design approach for miniaturized laser systems and new automation concepts for a robot-based precision assembly, as well as passive and active alignment methods, which are based on a self-optimizing approach. Very promising results have already been achieved, considerably reducing the duration and complexity of the laser resonator assembly. These results as well as future development perspectives are discussed.

Microwave power transmission system studies. Volume 3, section 8: Mechanical systems and flight operations

NASA Technical Reports Server (NTRS)

Maynard, O. E.; Brown, W. C.; Edwards, A.; Haley, J. T.; Meltz, G.; Howell, J. M.; Nathan, A.

1975-01-01

The efforts and recommendations associated with preliminary design and concept definition for mechanical systems and flight operations are presented. Technical discussion in the areas of mission analysis, antenna structural concept, configuration analysis, assembly and packaging with associated costs are presented. Technology issues for the control system, structural system, thermal system and assembly including cost and man's role in assembly and maintenance are identified. Background and desired outputs for future efforts are discussed.

Cytoskeletal motor-driven active self-assembly in in vitro systems

DOE PAGES

Lam, A. T.; VanDelinder, V.; Kabir, A. M. R.; ...

2015-11-11

Molecular motor-driven self-assembly has been an active area of soft matter research for the past decade. Because molecular motors transform chemical energy into mechanical work, systems which employ molecular motors to drive self-assembly processes are able to overcome kinetic and thermodynamic limits on assembly time, size, complexity, and structure. Here, we review the progress in elucidating and demonstrating the rules and capabilities of motor-driven active self-assembly. Lastly, we focus on the types of structures created and the degree of control realized over these structures, and discuss the next steps necessary to achieve the full potential of this assembly mode whichmore » complements robotic manipulation and passive self-assembly.« less

Machine learning assembly landscapes from particle tracking data.

PubMed

Long, Andrew W; Zhang, Jie; Granick, Steve; Ferguson, Andrew L

2015-11-07

Bottom-up self-assembly offers a powerful route for the fabrication of novel structural and functional materials. Rational engineering of self-assembling systems requires understanding of the accessible aggregation states and the structural assembly pathways. In this work, we apply nonlinear machine learning to experimental particle tracking data to infer low-dimensional assembly landscapes mapping the morphology, stability, and assembly pathways of accessible aggregates as a function of experimental conditions. To the best of our knowledge, this represents the first time that collective order parameters and assembly landscapes have been inferred directly from experimental data. We apply this technique to the nonequilibrium self-assembly of metallodielectric Janus colloids in an oscillating electric field, and quantify the impact of field strength, oscillation frequency, and salt concentration on the dominant assembly pathways and terminal aggregates. This combined computational and experimental framework furnishes new understanding of self-assembling systems, and quantitatively informs rational engineering of experimental conditions to drive assembly along desired aggregation pathways.

In-Space Assembly Capability Assessment for Potential Human Exploration and Science Applications

NASA Technical Reports Server (NTRS)

Jefferies, Sharon A.; Jones, Christopher A.; Arney, Dale C.; Stillwagen, Frederic H.; Chai, Patrick R.; Hutchinson, Craig D.; Stafford, Matthew A.; Moses, Robert W.; Dempsey, James A.; Rodgers, Erica M.;

Lunar surface construction and assembly equipment study: Lunar Base Systems Study (LBSS) task 5.3

NASA Technical Reports Server (NTRS)

1988-01-01

A set of construction and assembly tasks required on the lunar surface was developed, different concepts for equipment applicable to the tasks determined, and leading candidate systems identified for future conceptual design. Data on surface construction and assembly equipment systems are necessary to facilitate an integrated review of a complete lunar scenario.

Paradigm shift from self-assembly to commanded assembly of functional materials: recent examples in porphyrin/fullerene supramolecular systems

NASA Astrophysics Data System (ADS)

Li, Mao; Ishihara, Shinsuke; Ji, Qingmin; Akada, Misaho; Hill, Jonathan P.; Ariga, Katsuhiko

2012-10-01

Current nanotechnology based on top-down nanofabrication may encounter a variety of drawbacks in the near future so that development of alternative methods, including the so-called bottom-up approach, has attracted considerable attention. However, the bottom-up strategy, which often relies on spontaneous self-assembly, might be inefficient in the development of the requisite functional materials and systems. Therefore, assembly processes controlled by external stimuli might be a plausible strategy for the development of bottom-up nanotechnology. In this review, we demonstrate a paradigm shift from self-assembly to commanded assembly by describing several examples of assemblies of typical functional molecules, i.e. porphyrins and fullerenes. In the first section, we describe recent progress in the design and study of self-assembled and co-assembled supramolecular architectures of porphyrins and fullerenes. Then, we show examples of assembly induced by external stimuli. We emphasize the paradigm shift from self-assembly to commanded assembly by describing the recently developed electrochemical-coupling layer-by-layer (ECC-LbL) methodology.

Robotic Assembly of Truss Structures for Space Systems and Future Research Plans

NASA Technical Reports Server (NTRS)

Doggett, William

2002-01-01

Many initiatives under study by both the space science and earth science communities require large space systems, i.e. with apertures greater than 15 m or dimensions greater than 20 m. This paper reviews the effort in NASA Langley Research Center's Automated Structural Assembly Laboratory which laid the foundations for robotic construction of these systems. In the Automated Structural Assembly Laboratory reliable autonomous assembly and disassembly of an 8 meter planar structure composed of 102 truss elements covered by 12 panels was demonstrated. The paper reviews the hardware and software design philosophy which led to reliable operation during weeks of near continuous testing. Special attention is given to highlight the features enhancing assembly reliability.

Lifetime predictions for dimmable two-channel drivers for color tuning luminaires

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

Davis, Lynn; Smith, Aaron; Clark, Terry

Two-channel tunable white lighting (TWL) systems represent the next wave of solid-state lighting (SSL) systems and promise flexibility in light environment while maintaining the high reliability and luminous efficacy expected with SSL devices. TWL systems utilize LED assemblies consisting of two different LED spectra (i.e., often a warm white assembly and a cool white assembly) that are integrated into modules. While these systems provide the ability to adjust the lighting spectrum to match the physiology needs of the task at hand, they also are a potentially more complex lighting system from a performance and reliability perspective. We report an initialmore » study on the reliability performance of such lighting systems including an examination of the lumen maintenance and chromaticity stability of warm white and cool white LED assemblies and the multi-channel driver that provides power to the assemblies. Accelerated stress tests including operational bake tests conducted at 75°C and 95°C were used to age the LED modules, while more aggressive temperature and humidity tests were used for the drivers in this study. Small differences in the performance between the two LED assemblies were found and can be attributed to the different phosphor chemistries. The lumen maintenances of both LED assemblies were excellent. The warm white LED assemblies were found to shift slightly in the green color direction over time while the cool white LED assemblies shifted slightly in the yellow color direction. The net result of these chromaticity shifts is a small, barely perceptible reduction in the tuning range after 6,000 hours of exposure to an accelerating elevated temperature of 75°C.« less

Stabilized PV system

DOEpatents

Dinwoodie, Thomas L.

2002-12-17

A stabilized PV system comprises an array of photovoltaic (PV) assemblies mounted to a support surface. Each PV assembly comprises a PV module and a support assembly securing the PV module to a position overlying the support surface. The array of modules is circumscribed by a continuous, belt-like perimeter assembly. Cross strapping, extending above, below or through the array, or some combination of above, below and through the array, secures a first position along the perimeter assembly to at least a second position along the perimeter assembly thereby stabilizing the array against wind uplift forces. The first and second positions may be on opposite sides on the array.

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

Berland, Brian Spencer; Lanning, Bruce Roy; Stowell, Jr., Michael Wayne

This disclosure describes system and methods for creating an autonomous electrochromic assembly, and systems and methods for use of the autonomous electrochromic assembly in combination with a window. Embodiments described herein include an electrochromic assembly that has an electrochromic device, an energy storage device, an energy collection device, and an electrochromic controller device. These devices may be combined into a unitary electrochromic insert assembly. The electrochromic assembly may have the capability of generating power sufficient to operate and control an electrochromic device. This control may occur through the application of a voltage to an electrochromic device to change its opacitymore » state. The electrochromic assembly may be used in combination with a window.« less

Microfluidic assembly blocks.

PubMed

Rhee, Minsoung; Burns, Mark A

2008-08-01

An assembly approach for microdevice construction using prefabricated microfluidic components is presented. Although microfluidic systems are convenient platforms for biological assays, their use in the life sciences is still limited mainly due to the high-level fabrication expertise required for construction. This approach involves prefabrication of individual microfluidic assembly blocks (MABs) in PDMS that can be readily assembled to form microfluidic systems. Non-expert users can assemble the blocks on glass slides to build their devices in minutes without any fabrication steps. In this paper, we describe the construction and assembly of the devices using the MAB methodology, and demonstrate common microfluidic applications including laminar flow development, valve control, and cell culture.

Automatic assembly of micro-optical components

NASA Astrophysics Data System (ADS)

Gengenbach, Ulrich K.

1996-12-01

Automatic assembly becomes an important issue as hybrid micro systems enter industrial fabrication. Moving from a laboratory scale production with manual assembly and bonding processes to automatic assembly requires a thorough re- evaluation of the design, the characteristics of the individual components and of the processes involved. Parts supply for automatic operation, sensitive and intelligent grippers adapted to size, surface and material properties of the microcomponents gain importance when the superior sensory and handling skills of a human are to be replaced by a machine. This holds in particular for the automatic assembly of micro-optical components. The paper outlines these issues exemplified at the automatic assembly of a micro-optical duplexer consisting of a micro-optical bench fabricated by the LIGA technique, two spherical lenses, a wavelength filter and an optical fiber. Spherical lenses, wavelength filter and optical fiber are supplied by third party vendors, which raises the question of parts supply for automatic assembly. The bonding processes for these components include press fit and adhesive bonding. The prototype assembly system with all relevant components e.g. handling system, parts supply, grippers and control is described. Results of first automatic assembly tests are presented.

Macromolecular crystal growing system

NASA Technical Reports Server (NTRS)

Snyder, Robert S. (Inventor); Herren, Blair J. (Inventor); Carter, Daniel C. (Inventor); Yost, Vaughn H. (Inventor); Bugg, Charles E. (Inventor); Delucas, Lawrence J. (Inventor); Suddath, Fred L. (Inventor)

1991-01-01

A macromolecular crystal growing system especially designed for growing crystals in the low gravity of space as well as the gravity of earth includes at least one tray assembly, a carrier assembly which receives the tray, and a refrigeration-incubation module in which the carrier assembly is received. The tray assembly includes a plurality of sealed chambers with a plastic syringe and a plug means for the double tip of the syringe provided therein. Ganging mechanisms operate the syringes and plugs simultaneously in a precise and smooth operation. Preferably, the tray assemblies are mounted on ball bearing slides for smooth operation in inserting and removing the tray assemblies into the carrier assembly. The plugging mechanism also includes a loading control mechanism. A mechanism for leaving a syringe unplugged is also provided.

EVALUATION OF A MULTIFUNCTIONAL VALVE ASSEMBLY IN A DIRECT EXPANSION REFRIGERATION SYSTEM REPORT

EPA Science Inventory

The report describes the performance, including energy consumption, of a refrigeration system incorporating a multifunctional valve (MXV assembly). The MXV assembly (consisting of additional liquid line, an XTC valve, and a larger thermostatic expansion valve) was installed on al...

76 FR 72686 - 36(b)(1) Arms Sales Notification

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-25

... Electromagnetic Aircraft Launch System/Advanced Arresting Gear (EMALS/AAG). The EMALS long lead sub-assemblies... United Kingdom--Electromagnetic Aircraft Launch System Long Lead Sub- Assemblies The Government of the United Kingdom (UK) has requested the long lead sub-assemblies for the Electromagnetic Aircraft Launch...

48 CFR 239.7409 - Special assembly.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Special assembly. 239.7409... Services 239.7409 Special assembly. (a) Special assembly is the designing, manufacturing, arranging... general use equipment. (b) Special assembly rates and charges shall be based on estimated costs. The...

48 CFR 239.7409 - Special assembly.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Special assembly. 239.7409... Services 239.7409 Special assembly. (a) Special assembly is the designing, manufacturing, arranging... general use equipment. (b) Special assembly rates and charges shall be based on estimated costs. The...

48 CFR 239.7409 - Special assembly.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Special assembly. 239.7409... Services 239.7409 Special assembly. (a) Special assembly is the designing, manufacturing, arranging... general use equipment. (b) Special assembly rates and charges shall be based on estimated costs. The...

48 CFR 239.7409 - Special assembly.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Special assembly. 239.7409... Services 239.7409 Special assembly. (a) Special assembly is the designing, manufacturing, arranging... general use equipment. (b) Special assembly rates and charges shall be based on estimated costs. The...

48 CFR 239.7409 - Special assembly.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Special assembly. 239.7409... Services 239.7409 Special assembly. (a) Special assembly is the designing, manufacturing, arranging... general use equipment. (b) Special assembly rates and charges shall be based on estimated costs. The...

Hydraulic system for a ratio change transmission

DOEpatents

Kalns, Ilmars

1981-01-01

Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

Nuclear reactor power for a space-based radar. SP-100 project

NASA Technical Reports Server (NTRS)

Bloomfield, Harvey; Heller, Jack; Jaffe, Leonard; Beatty, Richard; Bhandari, Pradeep; Chow, Edwin; Deininger, William; Ewell, Richard; Fujita, Toshio; Grossman, Merlin

1986-01-01

A space-based radar mission and spacecraft, using a 300 kWe nuclear reactor power system, has been examined, with emphasis on aspects affecting the power system. The radar antenna is a horizontal planar array, 32 X 64 m. The orbit is at 61 deg, 1088 km. The mass of the antenna with support structure is 42,000 kg; of the nuclear reactor power system, 8,300 kg; of the whole spacecraft about 51,000 kg, necessitating multiple launches and orbital assembly. The assembly orbit is at 57 deg, 400 km, high enough to provide the orbital lifetime needed for orbital assembly. The selected scenario uses six Shuttle launches to bring the spacecraft and a Centaur G upper-stage vehicle to assembly orbit. After assembly, the Centaur places the spacecraft in operational orbit, where it is deployed on radio command, the power system started, and the spacecraft becomes operational. Electric propulsion is an alternative and allows deployment in assembly orbit, but introduces a question of nuclear safety.

Framework for Defining and Assessing Benefits of a Modular Assembly Design Approach for Exploration Systems

NASA Technical Reports Server (NTRS)

Dorsey, John T.; Collins, Timothy J.; Moe, Rud V.; Doggett,. William R.

2006-01-01

A comprehensive modular assembly system model has been proposed that extends the art from modular hardware, to include in-space assembly, servicing and repair and it s critical components of infrastructure, agents and assembly operations. Benefits of modular assembly have been identified and a set of metrics defined that extends the art beyond the traditional measures of performance, with emphasis on criteria that allow life-cycle mission costs to be used as a figure of merit (and include all substantive terms that have an impact on the evaluation). The modular assembly approach was used as a basis for developing a Solar Electric Transfer Vehicle (SETV) concept and three modular assembly scenarios were developed. The modular assembly approach also allows the SETV to be entered into service much earlier than competing conventional configurations and results in a great deal of versatility in accommodating different launch vehicle payload capabilities, allowing for modules to be pre-assembled before launch or assembled on orbit, without changing the space vehicle design.

Status of the Regenerative ECLS Water Recovery System

NASA Technical Reports Server (NTRS)

Carter, Donald Layne

2010-01-01

The regenerative Water Recovery System (WRS) has completed its first full year of operation on the International Space Station (ISS). The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the on-orbit status as of May 2010, and describes the technical challenges encountered and lessons learned over the past year.

Microscale mass spectrometry systems, devices and related methods

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

Ramsey, John Michael

Mass spectrometry systems or assemblies therefore include an ionizer that includes at least one planar conductor, a mass analyzer with a planar electrode assembly, and a detector comprising at least one planar conductor. The ionizer, the mass analyzer and the detector are attached together in a compact stack assembly. The stack assembly has a perimeter that bounds an area that is between about 0.01 mm.sup.2 to about 25 cm.sup.2 and the stack assembly has a thickness that is between about 0.1 mm to about 25 mm.

Alignment of optical system components using an ADM beam through a null assembly

NASA Technical Reports Server (NTRS)

Hayden, Joseph E. (Inventor); Olczak, Eugene G. (Inventor)

2010-01-01

A system for testing an optical surface includes a rangefinder configured to emit a light beam and a null assembly located between the rangefinder and the optical surface. The null assembly is configured to receive and to reflect the emitted light beam toward the optical surface. The light beam reflected from the null assembly is further reflected back from the optical surface toward the null assembly as a return light beam. The rangefinder is configured to measure a distance to the optical surface using the return light beam.

Microscale mass spectrometry systems, devices and related methods

DOEpatents

Ramsey, John Michael

2016-06-21

Mass spectrometry systems or assemblies therefore include an ionizer that includes at least one planar conductor, a mass analyzer with a planar electrode assembly, and a detector comprising at least one planar conductor. The ionizer, the mass analyzer and the detector are attached together in a compact stack assembly. The stack assembly has a perimeter that bounds an area that is between about 0.01 mm.sup.2 to about 25 cm.sup.2 and the stack assembly has a thickness that is between about 0.1 mm to about 25 mm.

SM, TVIS Chassis Assembly, Treadmill Belt Assembly, Top

NASA Image and Video Library

2002-01-01

jsc2002e38738 (2002) --- Top view of the Treadmill Belt Assembly on the Treadmill Vibration Isolation System (TVIS) Chassis Assembly for use in the International Space Station (ISS) Service Module (SM).

Self-assembly of proglycinin and hybrid proglycinin synthesized in vitro from cDNA

PubMed Central

Dickinson, Craig D.; Floener, Liliane A.; Lilley, Glenn G.; Nielsen, Niels C.

1987-01-01

An in vitro system was developed that results in the self-assembly of subunit precursors into complexes that resemble those found naturally in the endoplasmic reticulum. Subunits of glycinin, the predominant seed protein of soybeans, were synthesized from modified cDNAs using a combination of the SP6 transcription and the rabbit reticulocyte translation systems. Subunits produced from plasmid constructions that encoded either Gy4 or Gy5 gene products, but modified such that their signal sequences were absent, self-assembled into trimers equivalent in size to those precursors found in the endoplasmic reticulum. In contrast, proteins synthesized in vitro from Gy4 constructs failed to self-assemble when the signal sequence was left intact (e.g., preproglycinin) or when the coding sequence was modified to remove 27 amino acids from an internal hydrophobic region, which is highly conserved among the glycinin subunits. Various hybrid subunits were also produced by trading portions of Gy4 and Gy5 cDNAs and all self-assembled in our system. The in vitro assembly system provides an opportunity to study the self-assembly of precursors and to probe for regions important for assembly. It will also be helpful in attempts to engineer beneficial nutritional changes into this important food protein. Images PMID:16593868

Tools and methods for automated assembly of miniaturized gear systems

NASA Astrophysics Data System (ADS)

Nienhaus, Matthias; Ehrfeld, Wolfgang; Berg, Udo; Schmitz, Felix; Soultan, H.

2000-10-01

The assembly of gear systems with the size of a pin head is almost beyond the bound of human tactile skills. The magic formula for series fabrication of this hybrid micro systems is the automation of the assembly process. As a contribution, this paper presents and discusses three different assembly methods comprising specifically developed tools for different types of planetary gears with outer diameters of 1.9 mm. Because of the huge importance for the complete micro assembly process, particular attention will be dedicated to the feeding and magazining of the micro gear components. Starting with metallic gear wheels as bulk good, an extremely miniaturized gear system of the Wolfram type has been automatically assembled by employing the strategy of tolerance compensation movement. As a key component, a modular tong gripper with specifically adapted gripping jaws produced by LIGA technology has been used. Further detailed investigations were spend on handling and assembly of micro injection moulded gear wheels made of POM for a three state planetary gear system. One strategy, following the idea of in situ observation, focuses on the intensive use of electronic pattern recognition. Alternatively, an unusual method based on a novel plastic wafer magazine will be discussed in detail. Hereby the exact position and orientation of injection moulded micro components will be presented from the manufacturing process up to the final micro assembly procedure. By simplifying the moulding of the micro gears as well as their handling, storing and assembly, this method has the potential to revolutionize the series fabrication of products with dimensions in the microscopic range in general.

Housing assembly for electric vehicle transaxle

DOEpatents

Kalns, Ilmars

1981-01-01

Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

Peripheral infrastructure vectors and an extended set of plant parts for the Modular Cloning system

PubMed Central

Kretschmer, Carola; Gruetzner, Ramona; Löfke, Christian; Dagdas, Yasin; Bürstenbinder, Katharina; Marillonnet, Sylvestre

2018-01-01

Standardized DNA assembly strategies facilitate the generation of multigene constructs from collections of building blocks in plant synthetic biology. A common syntax for hierarchical DNA assembly following the Golden Gate principle employing Type IIs restriction endonucleases was recently developed, and underlies the Modular Cloning and GoldenBraid systems. In these systems, transcriptional units and/or multigene constructs are assembled from libraries of standardized building blocks, also referred to as phytobricks, in several hierarchical levels and by iterative Golden Gate reactions. Here, a toolkit containing further modules for the novel DNA assembly standards was developed. Intended for use with Modular Cloning, most modules are also compatible with GoldenBraid. Firstly, a collection of approximately 80 additional phytobricks is provided, comprising e.g. modules for inducible expression systems, promoters or epitope tags. Furthermore, DNA modules were developed for connecting Modular Cloning and Gateway cloning, either for toggling between systems or for standardized Gateway destination vector assembly. Finally, first instances of a “peripheral infrastructure” around Modular Cloning are presented: While available toolkits are designed for the assembly of plant transformation constructs, vectors were created to also use coding sequence-containing phytobricks directly in yeast two hybrid interaction or bacterial infection assays. The presented material will further enhance versatility of hierarchical DNA assembly strategies. PMID:29847550

Software design for automated assembly of truss structures

NASA Technical Reports Server (NTRS)

Herstrom, Catherine L.; Grantham, Carolyn; Allen, Cheryl L.; Doggett, William R.; Will, Ralph W.

1992-01-01

Concern over the limited intravehicular activity time has increased the interest in performing in-space assembly and construction operations with automated robotic systems. A technique being considered at LaRC is a supervised-autonomy approach, which can be monitored by an Earth-based supervisor that intervenes only when the automated system encounters a problem. A test-bed to support evaluation of the hardware and software requirements for supervised-autonomy assembly methods was developed. This report describes the design of the software system necessary to support the assembly process. The software is hierarchical and supports both automated assembly operations and supervisor error-recovery procedures, including the capability to pause and reverse any operation. The software design serves as a model for the development of software for more sophisticated automated systems and as a test-bed for evaluation of new concepts and hardware components.

Preliminary control/structure interaction study of coupled Space Station Freedom/Assembly Work Platform/orbiter

NASA Technical Reports Server (NTRS)

Singh, Sudeep K.; Lindenmoyer, Alan J.

1989-01-01

Results are presented from a preliminary control/structure interaction study of the Space Station, the Assembly Work Platform, and the STS orbiter dynamics coupled with the orbiter and station control systems. The first three Space Station assembly flight configurations and their finite element representations are illustrated. These configurations are compared in terms of control authority in each axis and propellant usage. The control systems design parameters during assembly are computed. Although the rigid body response was acceptable with the orbiter Primary Reaction Control System, the flexible body response showed large structural deflections and loads. It was found that severe control/structure interaction occurred if the stiffness of the Assembly Work Platform was equal to that of the station truss. Also, the response of the orbiter Vernier Reaction Control System to small changes in inertia properties is examined.

Optimisation of assembly scheduling in VCIM systems using genetic algorithm

NASA Astrophysics Data System (ADS)

Dao, Son Duy; Abhary, Kazem; Marian, Romeo

2017-09-01

Assembly plays an important role in any production system as it constitutes a significant portion of the lead time and cost of a product. Virtual computer-integrated manufacturing (VCIM) system is a modern production system being conceptually developed to extend the application of traditional computer-integrated manufacturing (CIM) system to global level. Assembly scheduling in VCIM systems is quite different from one in traditional production systems because of the difference in the working principles of the two systems. In this article, the assembly scheduling problem in VCIM systems is modeled and then an integrated approach based on genetic algorithm (GA) is proposed to search for a global optimised solution to the problem. Because of dynamic nature of the scheduling problem, a novel GA with unique chromosome representation and modified genetic operations is developed herein. Robustness of the proposed approach is verified by a numerical example.

Component model reduction via the projection and assembly method

NASA Technical Reports Server (NTRS)

Bernard, Douglas E.

1989-01-01

The problem of acquiring a simple but sufficiently accurate model of a dynamic system is made more difficult when the dynamic system of interest is a multibody system comprised of several components. A low order system model may be created by reducing the order of the component models and making use of various available multibody dynamics programs to assemble them into a system model. The difficulty is in choosing the reduced order component models to meet system level requirements. The projection and assembly method, proposed originally by Eke, solves this difficulty by forming the full order system model, performing model reduction at the the system level using system level requirements, and then projecting the desired modes onto the components for component level model reduction. The projection and assembly method is analyzed to show the conditions under which the desired modes are captured exactly; to the numerical precision of the algorithm.

Multiligand Metal-Phenolic Assembly from Green Tea Infusions.

PubMed

Rahim, Md Arifur; Björnmalm, Mattias; Bertleff-Zieschang, Nadja; Ju, Yi; Mettu, Srinivas; Leeming, Michael G; Caruso, Frank

2018-03-07

The synthesis of hybrid functional materials using the coordination-driven assembly of metal-phenolic networks (MPNs) is of interest in diverse areas of materials science. To date, MPN assembly has been explored as monoligand systems (i.e., containing a single type of phenolic ligand) where the phenolic components are primarily obtained from natural sources via extraction, isolation, and purification processes. Herein, we demonstrate the fabrication of MPNs from a readily available, crude phenolic source-green tea (GT) infusions. We employ our recently introduced rust-mediated continuous assembly strategy to prepare these GT MPN systems. The resulting hollow MPN capsules contain multiple phenolic ligands and have a shell thickness that can be controlled through the reaction time. These multiligand MPN systems have different properties compared to the analogous MPN systems reported previously. For example, the Young's modulus (as determined using colloidal-probe atomic force microscopy) of the GT MPN system presented herein is less than half that of MPN systems prepared using tannic acid and iron salt solutions, and the disassembly kinetics are faster (∼50%) than other, comparable MPN systems under identical disassembly conditions. Additionally, the use of rust-mediated assembly enables the formation of stable capsules under conditions where the conventional approach (i.e., using iron salt solutions) results in colloidally unstable dispersions. These differences highlight how the choice of phenolic ligand and its source, as well as the assembly protocol (e.g., using solution-based or solid-state iron sources), can be used to tune the properties of MPNs. The strategy presented herein expands the toolbox of MPN assembly while also providing new insights into the nature and robustness of metal-phenolic interfacial assembly when using solution-based or solid-state metal sources.

Optoelectronic functional materials based on alkylated-π molecules: self-assembled architectures and nonassembled liquids.

PubMed

Li, Hongguang; Choi, Jiyoung; Nakanishi, Takashi

2013-05-07

The engineering of single molecules into higher-order hierarchical assemblies is a current research focus in molecular materials chemistry. Molecules containing π-conjugated units are an important class of building blocks because their self-assembly is not only of fundamental interest, but also the key to fabricating functional systems for organic electronic and photovoltaic applications. Functionalizing the π-cores with "alkyl chains" is a common strategy in the molecular design that can give the system desirable properties, such as good solubility in organic solvents for solution processing. Moreover, the alkylated-π system can regulate the self-assembly behavior by fine-tuning the intermolecular forces. The optimally assembled structures can then exhibit advanced functions. However, while some general rules have been revealed, a comprehensive understanding of the function played by the attached alkyl chains is still lacking, and current methodology is system-specific in many cases. Better clarification of this issue requires contributions from carefully designed libraries of alkylated-π molecular systems in both self-assembly and nonassembly materialization strategies. Here, based on recent efforts toward this goal, we show the power of the alkyl chains in controlling the self-assembly of soft molecular materials and their resulting optoelectronic properties. The design of alkylated-C60 is selected from our recent research achievements, as the most attractive example of such alkylated-π systems. Some other closely related systems composed of alkyl chains and π-units are also reviewed to indicate the universality of the methodology. Finally, as a contrast to the self-assembled molecular materials, nonassembled, solvent-free, novel functional liquid materials are discussed. In doing so, a new journey toward the ultimate organic "soft" materials is introduced, based on alkylated-π molecular design.

High-power fused assemblies enabled by advances in fiber-processing technologies

NASA Astrophysics Data System (ADS)

Wiley, Robert; Clark, Brett

2011-02-01

The power handling capabilities of fiber lasers are limited by the technologies available to fabricate and assemble the key optical system components. Previous tools for the assembly, tapering, and fusion of fiber laser elements have had drawbacks with regard to temperature range, alignment capability, assembly flexibility and surface contamination. To provide expanded capabilities for fiber laser assembly, a wide-area electrical plasma heat source was used in conjunction with an optimized image analysis method and a flexible alignment system, integrated according to mechatronic principles. High-resolution imaging and vision-based measurement provided feedback to adjust assembly, fusion, and tapering process parameters. The system was used to perform assembly steps including dissimilar-fiber splicing, tapering, bundling, capillary bundling, and fusion of fibers to bulk optic devices up to several mm in diameter. A wide range of fiber types and diameters were tested, including extremely large diameters and photonic crystal fibers. The assemblies were evaluated for conformation to optical and mechanical design criteria, such as taper geometry and splice loss. The completed assemblies met the performance targets and exhibited reduced surface contamination compared to assemblies prepared on previously existing equipment. The imaging system and image analysis algorithms provided in situ fiber geometry measurement data that agreed well with external measurement. The ability to adjust operating parameters dynamically based on imaging was shown to provide substantial performance benefits, particularly in the tapering of fibers and bundles. The integrated design approach was shown to provide sufficient flexibility to perform all required operations with a minimum of reconfiguration.

An Efficient and Versatile Means for Assembling and Manufacturing Systems in Space

NASA Technical Reports Server (NTRS)

Dorsey, John T.; Doggett, William R.; Hafley, Robert A.; Komendera, Erik; Correll, Nikolaus; King, Bruce

2012-01-01

Within NASA Space Science, Exploration and the Office of Chief Technologist, there are Grand Challenges and advanced future exploration, science and commercial mission applications that could benefit significantly from large-span and large-area structural systems. Of particular and persistent interest to the Space Science community is the desire for large (in the 10- 50 meter range for main aperture diameter) space telescopes that would revolutionize space astronomy. Achieving these systems will likely require on-orbit assembly, but previous approaches for assembling large-scale telescope truss structures and systems in space have been perceived as very costly because they require high precision and custom components. These components rely on a large number of mechanical connections and supporting infrastructure that are unique to each application. In this paper, a new assembly paradigm that mitigates these concerns is proposed and described. A new assembly approach, developed to implement the paradigm, is developed incorporating: Intelligent Precision Jigging Robots, Electron-Beam welding, robotic handling/manipulation, operations assembly sequence and path planning, and low precision weldable structural elements. Key advantages of the new assembly paradigm, as well as concept descriptions and ongoing research and technology development efforts for each of the major elements are summarized.

Adaptation of a Filter Assembly to Assess Microbial Bioburden of Pressurant Within a Propulsion System

NASA Technical Reports Server (NTRS)

Benardini, James N.; Koukol, Robert C.; Schubert, Wayne W.; Morales, Fabian; Klatte, Marlin F.

2012-01-01

A report describes an adaptation of a filter assembly to enable it to be used to filter out microorganisms from a propulsion system. The filter assembly has previously been used for particulates greater than 2 micrometers. Projects that utilize large volumes of nonmetallic materials of planetary protection concern pose a challenge to their bioburden budget, as a conservative specification value of 30 spores per cubic centimeter is typically used. Helium was collected utilizing an adapted filtration approach employing an existing Millipore filter assembly apparatus used by the propulsion team for particulate analysis. The filter holder on the assembly has a 47-mm diameter, and typically a 1.2-5 micrometer pore-size filter is used for particulate analysis making it compatible with commercially available sterilization filters (0.22 micrometers) that are necessary for biological sampling. This adaptation to an existing technology provides a proof-of-concept and a demonstration of successful use in a ground equipment system. This adaptation has demonstrated that the Millipore filter assembly can be utilized to filter out microorganisms from a propulsion system, whereas in previous uses the filter assembly was utilized for particulates greater than 2 micrometers.

Task planning and control synthesis for robotic manipulation in space applications

NASA Technical Reports Server (NTRS)

Sanderson, A. C.; Peshkin, M. A.; Homem-De-mello, L. S.

1987-01-01

Space-based robotic systems for diagnosis, repair and assembly of systems will require new techniques of planning and manipulation to accomplish these complex tasks. Results of work in assembly task representation, discrete task planning, and control synthesis which provide a design environment for flexible assembly systems in manufacturing applications, and which extend to planning of manipulatiuon operations in unstructured environments are summarized. Assembly planning is carried out using the AND/OR graph representation which encompasses all possible partial orders of operations and may be used to plan assembly sequences. Discrete task planning uses the configuration map which facilitates search over a space of discrete operations parameters in sequential operations in order to achieve required goals in the space of bounded configuration sets.

Two-speed transaxle

DOEpatents

Kalns, Ilmars

1981-01-01

Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

Self-assembled peptide nanostructures for functional materials

NASA Astrophysics Data System (ADS)

Sardan Ekiz, Melis; Cinar, Goksu; Aref Khalily, Mohammad; Guler, Mustafa O.

2016-10-01

Nature is an important inspirational source for scientists, and presents complex and elegant examples of adaptive and intelligent systems created by self-assembly. Significant effort has been devoted to understanding these sophisticated systems. The self-assembly process enables us to create supramolecular nanostructures with high order and complexity, and peptide-based self-assembling building blocks can serve as suitable platforms to construct nanostructures showing diverse features and applications. In this review, peptide-based supramolecular assemblies will be discussed in terms of their synthesis, design, characterization and application. Peptide nanostructures are categorized based on their chemical and physical properties and will be examined by rationalizing the influence of peptide design on the resulting morphology and the methods employed to characterize these high order complex systems. Moreover, the application of self-assembled peptide nanomaterials as functional materials in information technologies and environmental sciences will be reviewed by providing examples from recently published high-impact studies.

System and method for heating ferrite magnet motors for low temperatures

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

Reddy, Patel Bhageerath; El-Refaie, Ayman Mohamed Fawzi; Huh, Kum-Kang

A system and method for heating ferrite permanent magnets in an electrical machine is disclosed. The permanent magnet machine includes a stator assembly and a rotor assembly, with a plurality of ferrite permanent magnets disposed within the stator assembly or the rotor assembly to generate a magnetic field that interacts with a stator magnetic field to produce a torque. A controller of the electrical machine is programmed to cause a primary field current to be applied to the stator windings to generate the stator magnetic field, so as to cause the rotor assembly to rotate relative to the stator assembly.more » The controller is further programmed to cause a secondary current to be applied to the stator windings to selectively generate a secondary magnetic field, the secondary magnetic field inducing eddy currents in at least one of the stator assembly and the rotor assembly to heat the ferrite permanent magnets.« less

Flashback resistant pre-mixer assembly

DOEpatents

Laster, Walter R [Oviedo, FL; Gambacorta, Domenico [Oviedo, FL

2012-02-14

A pre-mixer assembly associated with a fuel supply system for mixing of air and fuel upstream from a main combustion zone in a gas turbine engine. The pre-mixer assembly includes a swirler assembly disposed about a fuel injector of the fuel supply system and a pre-mixer transition member. The swirler assembly includes a forward end defining an air inlet and an opposed aft end. The pre-mixer transition member has a forward end affixed to the aft end of the swirler assembly and an opposed aft end defining an outlet of the pre-mixer assembly. The aft end of the pre-mixer transition member is spaced from a base plate such that a gap is formed between the aft end of the pre-mixer transition member and the base plate for permitting a flow of purge air therethrough to increase a velocity of the air/fuel mixture exiting the pre-mixer assembly.

System and method for heating ferrite magnet motors for low temperatures

DOEpatents

Reddy, Patel Bhageerath; El-Refaie, Ayman Mohamed Fawzi; Huh, Kum-Kang

2017-07-04

A system and method for heating ferrite permanent magnets in an electrical machine is disclosed. The permanent magnet machine includes a stator assembly and a rotor assembly, with a plurality of ferrite permanent magnets disposed within the stator assembly or the rotor assembly to generate a magnetic field that interacts with a stator magnetic field to produce a torque. A controller of the electrical machine is programmed to cause a primary field current to be applied to the stator windings to generate the stator magnetic field, so as to cause the rotor assembly to rotate relative to the stator assembly. The controller is further programmed to cause a secondary current to be applied to the stator windings to selectively generate a secondary magnetic field, the secondary magnetic field inducing eddy currents in at least one of the stator assembly and the rotor assembly to heat the ferrite permanent magnets.

Classification of coordination polygons and polyhedra according to their mode of self-assembly.

PubMed

Swiegers, G F; Malefetse, T J

2001-09-03

This work extends techniques for the controlled formation of synthetic molecular containers by metal-mediated self-assembly. A new classification system based on the self-assembly of such species is proposed. The system: 1) allows a systematic identification of suitable acceptor-donor combinations, 2) widens the variety of design possibilities available, 3) allows a ready comparison of the self-assembly of different compounds, 4) reveals useful commonalities between different compounds, 5) aids in the development of novel architectures, and 6) permits identification of systems capable of being switched back-and-forth between architectures.

Industrial-scale spray layer-by-layer assembly for production of biomimetic photonic systems.

PubMed

Krogman, K C; Cohen, R E; Hammond, P T; Rubner, M F; Wang, B N

2013-12-01

Layer-by-layer assembly is a powerful and flexible thin film process that has successfully reproduced biomimetic photonic systems such as structural colour. While most of the seminal work has been carried out using slow and ultimately unscalable immersion assembly, recent developments using spray layer-by-layer assembly provide a platform for addressing challenges to scale-up and manufacturability. A series of manufacturing systems has been developed to increase production throughput by orders of magnitude, making commercialized structural colour possible. Inspired by biomimetic photonic structures we developed and demonstrated a heat management system that relies on constructive reflection of near infrared radiation to bring about dramatic reductions in heat content.

MIDAS: A Modular DNA Assembly System for Synthetic Biology.

PubMed

van Dolleweerd, Craig J; Kessans, Sarah A; Van de Bittner, Kyle C; Bustamante, Leyla Y; Bundela, Rudranuj; Scott, Barry; Nicholson, Matthew J; Parker, Emily J

2018-04-20

A modular and hierarchical DNA assembly platform for synthetic biology based on Golden Gate (Type IIS restriction enzyme) cloning is described. This enabling technology, termed MIDAS (for Modular Idempotent DNA Assembly System), can be used to precisely assemble multiple DNA fragments in a single reaction using a standardized assembly design. It can be used to build genes from libraries of sequence-verified, reusable parts and to assemble multiple genes in a single vector, with full user control over gene order and orientation, as well as control of the direction of growth (polarity) of the multigene assembly, a feature that allows genes to be nested between other genes or genetic elements. We describe the detailed design and use of MIDAS, exemplified by the reconstruction, in the filamentous fungus Penicillium paxilli, of the metabolic pathway for production of paspaline and paxilline, key intermediates in the biosynthesis of a range of indole diterpenes-a class of secondary metabolites produced by several species of filamentous fungi. MIDAS was used to efficiently assemble a 25.2 kb plasmid from 21 different modules (seven genes, each composed of three basic parts). By using a parts library-based system for construction of complex assemblies, and a unique set of vectors, MIDAS can provide a flexible route to assembling tailored combinations of genes and other genetic elements, thereby supporting synthetic biology applications in a wide range of expression hosts.

Meshing complex macro-scale objects into self-assembling bricks

PubMed Central

Hacohen, Adar; Hanniel, Iddo; Nikulshin, Yasha; Wolfus, Shuki; Abu-Horowitz, Almogit; Bachelet, Ido

2015-01-01

Self-assembly provides an information-economical route to the fabrication of objects at virtually all scales. However, there is no known algorithm to program self-assembly in macro-scale, solid, complex 3D objects. Here such an algorithm is described, which is inspired by the molecular assembly of DNA, and based on bricks designed by tetrahedral meshing of arbitrary objects. Assembly rules are encoded by topographic cues imprinted on brick faces while attraction between bricks is provided by embedded magnets. The bricks can then be mixed in a container and agitated, leading to properly assembled objects at high yields and zero errors. The system and its assembly dynamics were characterized by video and audio analysis, enabling the precise time- and space-resolved characterization of its performance and accuracy. Improved designs inspired by our system could lead to successful implementation of self-assembly at the macro-scale, allowing rapid, on-demand fabrication of objects without the need for assembly lines. PMID:26226488

Equilibrium polymerization models of re-entrant self-assembly

NASA Astrophysics Data System (ADS)

Dudowicz, Jacek; Douglas, Jack F.; Freed, Karl F.

2009-04-01

As is well known, liquid-liquid phase separation can occur either upon heating or cooling, corresponding to lower and upper critical solution phase boundaries, respectively. Likewise, self-assembly transitions from a monomeric state to an organized polymeric state can proceed either upon increasing or decreasing temperature, and the concentration dependent ordering temperature is correspondingly called the "floor" or "ceiling" temperature. Motivated by the fact that some phase separating systems exhibit closed loop phase boundaries with two critical points, the present paper analyzes self-assembly analogs of re-entrant phase separation, i.e., re-entrant self-assembly. In particular, re-entrant self-assembly transitions are demonstrated to arise in thermally activated equilibrium self-assembling systems, when thermal activation is more favorable than chain propagation, and in equilibrium self-assembly near an adsorbing boundary where strong competition exists between adsorption and self-assembly. Apparently, the competition between interactions or equilibria generally underlies re-entrant behavior in both liquid-liquid phase separation and self-assembly transitions.

Fiber coupled optical spark delivery system

DOEpatents

Yalin, Azer; Willson, Bryan; Defoort, Morgan

2008-08-12

A spark delivery system for generating a spark using a laser beam is provided, the spark delivery system including a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. In addition, the laser delivery assembly includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. In accordance with embodiments of the present invention, the assembly may be used to create a spark in a combustion engine. In accordance with other embodiments of the present invention, a method of using the spark delivery system is provided. In addition, a method of choosing an appropriate fiber for creating a spark using a laser beam is also presented.

GoldenBraid: An Iterative Cloning System for Standardized Assembly of Reusable Genetic Modules

PubMed Central

Sarrion-Perdigones, Alejandro; Falconi, Erica Elvira; Zandalinas, Sara I.; Juárez, Paloma; Fernández-del-Carmen, Asun; Granell, Antonio; Orzaez, Diego

2011-01-01

Synthetic Biology requires efficient and versatile DNA assembly systems to facilitate the building of new genetic modules/pathways from basic DNA parts in a standardized way. Here we present GoldenBraid (GB), a standardized assembly system based on type IIS restriction enzymes that allows the indefinite growth of reusable gene modules made of standardized DNA pieces. The GB system consists of a set of four destination plasmids (pDGBs) designed to incorporate multipartite assemblies made of standard DNA parts and to combine them binarily to build increasingly complex multigene constructs. The relative position of type IIS restriction sites inside pDGB vectors introduces a double loop (“braid”) topology in the cloning strategy that allows the indefinite growth of composite parts through the succession of iterative assembling steps, while the overall simplicity of the system is maintained. We propose the use of GoldenBraid as an assembly standard for Plant Synthetic Biology. For this purpose we have GB-adapted a set of binary plasmids for A. tumefaciens-mediated plant transformation. Fast GB-engineering of several multigene T-DNAs, including two alternative modules made of five reusable devices each, and comprising a total of 19 basic parts are also described. PMID:21750718

GoldenBraid: an iterative cloning system for standardized assembly of reusable genetic modules.

PubMed

Sarrion-Perdigones, Alejandro; Falconi, Erica Elvira; Zandalinas, Sara I; Juárez, Paloma; Fernández-del-Carmen, Asun; Granell, Antonio; Orzaez, Diego

2011-01-01

Synthetic Biology requires efficient and versatile DNA assembly systems to facilitate the building of new genetic modules/pathways from basic DNA parts in a standardized way. Here we present GoldenBraid (GB), a standardized assembly system based on type IIS restriction enzymes that allows the indefinite growth of reusable gene modules made of standardized DNA pieces. The GB system consists of a set of four destination plasmids (pDGBs) designed to incorporate multipartite assemblies made of standard DNA parts and to combine them binarily to build increasingly complex multigene constructs. The relative position of type IIS restriction sites inside pDGB vectors introduces a double loop ("braid") topology in the cloning strategy that allows the indefinite growth of composite parts through the succession of iterative assembling steps, while the overall simplicity of the system is maintained. We propose the use of GoldenBraid as an assembly standard for Plant Synthetic Biology. For this purpose we have GB-adapted a set of binary plasmids for A. tumefaciens-mediated plant transformation. Fast GB-engineering of several multigene T-DNAs, including two alternative modules made of five reusable devices each, and comprising a total of 19 basic parts are also described.

Both anticipatory and compensatory postural adjustments are adapted while catching a ball in unstable standing posture.

PubMed

Scariot, Vanessa; Rios, Jaqueline L; Claudino, Renato; Dos Santos, Eloá C; Angulski, Hanna B B; Dos Santos, Marcio J

2016-01-01

The main objective of this study was to analyze the role of balance exercises on anticipatory (APA) and compensatory (CPA) postural adjustments in different conditions of postural stability. Sixteen subjects were required to catch a ball while standing on rigid floor, trampoline and foam cushion surfaces. Electromyographic activities (EMG) of postural muscles were analyzed during time windows typical for APAs and CPAs. Overall there were a reciprocal activation of the muscles around the ankle and co-activations between ventral and dorsal muscles of the thigh and trunk during the catching a ball task. Compared to the rigid floor, the tibialis anterior activation was greater during the trampoline condition (CPA: p = 0.006) and the soleus muscle inhibition was higher during foam cushion condition (APA: p = 0.001; CPA: p = 0.007). Thigh and trunk muscle activities were similar across the conditions. These results advance the knowledge in postural control during body perturbations standing on unstable surfaces. Published by Elsevier Ltd.

Ultrasonic scanning system for in-place inspection of brazed-tube joints

NASA Technical Reports Server (NTRS)

Haralson, H. S.; Haynes, J. L.; Wages, C. G.

1971-01-01

System detects defects of .051 cm in diameter and larger. System incorporates scanning head assembly including boot enclosed transducer, slip ring assembly, drive mechanism, and servotransmitter. Ultrasonic flaw detector, prototype recorder, and special recorder complete system.

Flexible pipe crawling device having articulated two axis coupling

DOEpatents

Zollinger, William T.

1994-01-01

An apparatus for moving through the linear and non-linear segments of piping systems. The apparatus comprises a front leg assembly, a rear leg assembly, a mechanism for extension and retraction of the front and rear leg assembles with respect to each other, such as an air cylinder, and a pivoting joint. One end of the flexible joint attaches to the front leg assembly and the other end to the air cylinder, which is also connected to the rear leg assembly. The air cylinder allows the front and rear leg assemblies to progress through a pipe in "inchworm" fashion, while the joint provides the flexibility necessary for the pipe crawler to negotiate non-linear piping segments. The flexible connecting joint is coupled with a spring-force suspension system that urges alignment of the front and rear leg assemblies with respect to each other. The joint and suspension system cooperate to provide a firm yet flexible connection between the front and rear leg assemblies to allow the pivoting of one with respect to the other while moving around a non-linear pipe segment, but restoring proper alignment coming out of the pipe bend.

Flexible pipe crawling device having articulated two axis coupling

DOEpatents

Zollinger, W.T.

1994-05-10

An apparatus is described for moving through the linear and non-linear segments of piping systems. The apparatus comprises a front leg assembly, a rear leg assembly, a mechanism for extension and retraction of the front and rear leg assembles with respect to each other, such as an air cylinder, and a pivoting joint. One end of the flexible joint attaches to the front leg assembly and the other end to the air cylinder, which is also connected to the rear leg assembly. The air cylinder allows the front and rear leg assemblies to progress through a pipe in inchworm' fashion, while the joint provides the flexibility necessary for the pipe crawler to negotiate non-linear piping segments. The flexible connecting joint is coupled with a spring-force suspension system that urges alignment of the front and rear leg assemblies with respect to each other. The joint and suspension system cooperate to provide a firm yet flexible connection between the front and rear leg assemblies to allow the pivoting of one with respect to the other while moving around a non-linear pipe segment, but restoring proper alignment coming out of the pipe bend. 4 figures.

Active control of complex, multicomponent self-assembly processes

NASA Astrophysics Data System (ADS)

Schulman, Rebecca

The kinetics of many complex biological self-assembly processes such as cytoskeletal assembly are precisely controlled by cells. Spatiotemporal control over rates of filament nucleation, growth and disassembly determine how self-assembly occurs and how the assembled form changes over time. These reaction rates can be manipulated by changing the concentrations of the components needed for assembly by activating or deactivating them. I will describe how we can use these principles to design driven self-assembly processes in which we assemble and disassemble multiple types of components to create micron-scale networks of semiflexible filaments assembled from DNA. The same set of primitive components can be assembled into many different, structures depending on the concentrations of different components and how designed, DNA-based chemical reaction networks manipulate these concentrations over time. These chemical reaction networks can in turn interpret environmental stimuli to direct complex, multistage response. Such a system is a laboratory for understanding complex active material behaviors, such as metamorphosis, self-healing or adaptation to the environment that are ubiquitous in biological systems but difficult to quantitatively characterize or engineer.

Solar central receiver heliostat reflector assembly

DOEpatents

Horton, Richard H.; Zdeb, John J.

1980-01-01

A heliostat reflector assembly for a solar central receiver system comprises a light-weight, readily assemblable frame which supports a sheet of stretchable reflective material and includes mechanism for selectively applying tension to and positioning the sheet to stretch it to optical flatness. The frame is mounted on and supported by a pipe pedestal assembly that, in turn, is installed in the ground. The frame is controllably driven in a predetermined way by a light-weight drive system so as to be angularly adjustable in both elevation and azimuth to track the sun and efficiently continuously reflect the sun's rays to a focal zone, i.e. central receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The frame may include a built-in system for testing for optical flatness of the reflector. The preferable geometric configuration of the reflector is octagonal; however, it may be other shapes, such as hexagonal, pentagonal or square. Several different embodiments of means for tensioning and positioning the reflector to achieve optical flatness are disclosed. The reflector assembly is based on the stretch frame concept which provides an extremely light-weight, simple, low-cost reflector assembly that may be driven for positioning and tracking by a light-weight, inexpensive drive system.

The assembly and use of continuous flow systems for chemical synthesis.

PubMed

Britton, Joshua; Jamison, Timothy F

2017-11-01

The adoption of and opportunities in continuous flow synthesis ('flow chemistry') have increased significantly over the past several years. Continuous flow systems provide improved reaction safety and accelerated reaction kinetics, and have synthesised several active pharmaceutical ingredients in automated reconfigurable systems. Although continuous flow platforms are commercially available, systems constructed 'in-lab' provide researchers with a flexible, versatile, and cost-effective alternative. Herein, we describe the assembly and use of a modular continuous flow apparatus from readily available and affordable parts in as little as 30 min. Once assembled, the synthesis of a sulfonamide by reacting 4-chlorobenzenesulfonyl chloride with dibenzylamine in a single reactor coil with an in-line quench is presented. This example reaction offers the opportunity to learn several important skills including reactor construction, charging of a back-pressure regulator, assembly of stainless-steel syringes, assembly of a continuous flow system with multiple junctions, and yield determination. From our extensive experience of single-step and multistep continuous flow synthesis, we also describe solutions to commonly encountered technical problems such as precipitation of solids ('clogging') and reactor failure. Following this protocol, a nonspecialist can assemble a continuous flow system from reactor coils, syringes, pumps, in-line liquid-liquid separators, drying columns, back-pressure regulators, static mixers, and packed-bed reactors.

Systems and assemblies for transferring high power laser energy through a rotating junction

DOEpatents

Norton, Ryan J.; McKay, Ryan P.; Fraze, Jason D.; Rinzler, Charles C.; Grubb, Daryl L.; Faircloth, Brian O.; Zediker, Mark S.

2016-01-26

There are provided high power laser devices and systems for transmitting a high power laser beam across a rotating assembly, including optical slip rings and optical rotational coupling assemblies. These devices can transmit the laser beam through the rotation zone in free space or within a fiber.

Management filters and species traits: Weed community assembly in long-term organic and conventional systems

USDA-ARS?s Scientific Manuscript database

Community assembly theory provides a useful framework to assess the response of weed communities to agricultural management systems and to improve the predictive power of weed science. Under this framework, weed community assembly is constrained by abiotic and biotic "filters" that act on species tr...

Adhesives for assembly of lightweight wood containers

Treesearch

R. S. Kurtenacker

1964-01-01

This report discusses the screening of various adhesive and mastic systems for possible use in assembling lightweight wood containers. Results showed that dynamic tests of simulated box corners correlated reasonably well with rough handling evaluations of eight selected systems when used to assemble lightweight wood boxes made from a Group I container wood....

Rotor component displacement measurement system

DOEpatents

Mercer, Gary D.; Li, Ming C.; Baum, Charles R.

2003-05-27

A measuring system for measuring axial displacement of a tube relative to an axially stationary component in a rotating rotor assembly includes at least one displacement sensor adapted to be located normal to a longitudinal axis of the tube; an insulated cable system adapted for passage through the rotor assembly; a rotatable proximitor module located axially beyond the rotor assembly to which the cables are connected; and a telemetry system operatively connected to the proximitor module for sampling signals from the proximitor module and forwarding data to a ground station.

A custom-tailored FAMOS burn-up meter for VVER 440 fuel assemblies

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

Simon, G.G.; Golochtchapov, S.; Glazov, A.G.

1995-12-31

The FAMOS fuel assembly monitoring system had been originally developed for monitoring irradiated fuel assemblies of the Karlsruhe Nuclear Research Center concentrating on neutron detection systems for special applications.The measurements in the past had demonstrated that FAMOS can perform precise measurements to control or measure with accuracy the main physical parameters of spent fuel. The FAMOS 3 system is specialized for burn-up determination of fuel assemblies. Thus it is possible to take into account the burn-up for the purposes of storage and transportation. The Kola NPP VVER 440 requirements necessitated developing an especially adopted FAMOS 3 system. In addition tomore » the passive neutron measurement, a gross gamma detection and a boron concentration monitoring system are implemented. The new system was constructed as well as tested in laboratory experiments. The monitoring system has been delivered to the customer and is ready for use.« less

Status of the International Space Station Regenerative ECLSS Water Recovery and Oxygen Generation Systems

NASA Technical Reports Server (NTRS)

Bagdigian, Robert M.; Cloud, Dale

2005-01-01

NASA is developing three racks containing regenerative water recovery and oxygen generation systems (WRS and OGS) for deployment on the International Space Station (ISS). The major assemblies included in these racks are the Water Processor Assembly (WPA), Urine Processor Assembly (UPA), Oxygen Generation Assembly (OGA), and the Power Supply Module (PSM) supporting the OGA. The WPA and OGA are provided by Hamilton Sundstrand Space Systems International (HSSSI), Inc., while the UPA and PSM are developed in- house by the Marshall Space Flight Center (MSFC). The assemblies have completed the manufacturing phase and are in various stages of testing and integration into the flight racks. This paper summarizes the status as of April 2005 and describes some of the technical challenges encountered and lessons learned over the past year.

Autonomous Mechanical Assembly on the Space Shuttle: An Overview

NASA Technical Reports Server (NTRS)

Raibert, M. H.

1979-01-01

The space shuttle will be equipped with a pair of 50 ft. manipulators used to handle payloads and to perform mechanical assembly operations. Although current plans call for these manipulators to be operated by a human teleoperator. The possibility of using results from robotics and machine intelligence to automate this shuttle assembly system was investigated. The major components of an autonomous mechanical assembly system are examined, along with the technology base upon which they depend. The state of the art in advanced automation is also assessed.

How HIV-1 Gag assembles in cells: putting together pieces of the puzzle

PubMed Central

Lingappa, Jaisri R; Reed, Jonathan C; Tanaka, Motoko; Chutiraka, Kasana; Robinson, Bridget A

2014-01-01

During the late stage of the viral life cycle, HIV-1 Gag assembles into a spherical immature capsid, and undergoes budding, release, and maturation. Here we review events involved in immature capsid assembly from the perspective of five different approaches used to study this process: mutational analysis, structural studies, assembly of purified recombinant Gag, assembly of newly-translated Gag in a cell-free system, and studies in cells using biochemical and imaging techniques. We summarize key findings obtained using each approach, point out where there is consensus, and highlight unanswered questions. Particular emphasis is placed on reconciling data suggesting that Gag assembles by two different paths, depending on the assembly environment. Specifically, in assembly systems that lack cellular proteins, high concentrations of Gag can spontaneously assemble using purified nucleic acid as a scaffold. However, in the more complex intracellular environment, barriers that limit self-assembly are present in the form of cellular proteins, organelles, host defenses, and the absence of free nucleic acid. To overcome these barriers and promote efficient immature capsid formation in an unfavorable environment, Gag appears to utilize an energy-dependent, host-catalyzed, pathway of assembly intermediates in cells. Overall, we show how data obtained using a variety of techniques has led to our current understanding of HIV assembly. PMID:25066606

Hybrid architecture active wavefront sensing and control system, and method

NASA Technical Reports Server (NTRS)

Feinberg, Lee D. (Inventor); Dean, Bruce H. (Inventor); Hyde, Tristram T. (Inventor)

2011-01-01

According to various embodiments, provided herein is an optical system and method that can be configured to perform image analysis. The optical system can comprise a telescope assembly and one or more hybrid instruments. The one or more hybrid instruments can be configured to receive image data from the telescope assembly and perform a fine guidance operation and a wavefront sensing operation, simultaneously, on the image data received from the telescope assembly.

Self-assembling nucleic acid delivery vehicles via linear, water-soluble, cyclodextrin-containing polymers.

PubMed

Davis, M E; Pun, S H; Bellocq, N C; Reineke, T M; Popielarski, S R; Mishra, S; Heidel, J D

2004-01-01

Non-viral (synthetic) nucleic acid delivery systems have the potential to provide for the practical application of nucleic acid-based therapeutics. We have designed and prepared a tunable, non-viral nucleic acid delivery system that self-assembles with nucleic acids and centers around a new class of polymeric materials; namely, linear, water-soluble cyclodextrin-containing polymers. The relationships between polymer structure and gene delivery are illustrated, and the roles of the cyclodextrin moieties for minimizing toxicity and forming inclusion complexes in the self-assembly processes are highlighted. This vehicle is the first example of a polymer-based gene delivery system formed entirely by self-assembly.

Precision Clean Hardware: Maintenance of Fluid Systems Cleanliness

NASA Technical Reports Server (NTRS)

Sharp, Sheila; Pedley, Mike; Bond, Tim; Quaglino, Joseph; Lorenz, Mary Jo; Bentz, Michael; Banta, Richard; Tolliver, Nancy; Golden, John; Levesque, Ray

2003-01-01

The ISS fluid systems are so complex that fluid system cleanliness cannot be verified at the assembly level. A "build clean / maintain clean" approach was used by all major fluid systems: Verify cleanliness at the detail and subassembly level. Maintain cleanliness during assembly.

Maximizing coupling-efficiency of high-power diode lasers utilizing hybrid assembly technology

NASA Astrophysics Data System (ADS)

Zontar, D.; Dogan, M.; Fulghum, S.; Müller, T.; Haag, S.; Brecher, C.

2015-03-01

In this paper, we present hybrid assembly technology to maximize coupling efficiency for spatially combined laser systems. High quality components, such as center-turned focusing units, as well as suitable assembly strategies are necessary to obtain highest possible output ratios. Alignment strategies are challenging tasks due to their complexity and sensitivity. Especially in low-volume production fully automated systems are economically at a disadvantage, as operator experience is often expensive. However reproducibility and quality of automatically assembled systems can be superior. Therefore automated and manual assembly techniques are combined to obtain high coupling efficiency while preserving maximum flexibility. The paper will describe necessary equipment and software to enable hybrid assembly processes. Micromanipulator technology with high step-resolution and six degrees of freedom provide a large number of possible evaluation points. Automated algorithms are necess ary to speed-up data gathering and alignment to efficiently utilize available granularity for manual assembly processes. Furthermore, an engineering environment is presented to enable rapid prototyping of automation tasks with simultaneous data ev aluation. Integration with simulation environments, e.g. Zemax, allows the verification of assembly strategies in advance. Data driven decision making ensures constant high quality, documents the assembly process and is a basis for further improvement. The hybrid assembly technology has been applied on several applications for efficiencies above 80% and will be discussed in this paper. High level coupling efficiency has been achieved with minimized assembly as a result of semi-automated alignment. This paper will focus on hybrid automation for optimizing and attaching turning mirrors and collimation lenses.

Design, manufacture, and test of coolant pump-motor assembly for Brayton power conversion system

NASA Technical Reports Server (NTRS)

Gabacz, L. E.

1973-01-01

The design, development, fabrication, and testing of seven coolant circulating pump-motor assemblies are discussed. The pump-motor assembly is driven by the nominal 44.4-volt, 400-Hz, 3-phase output of a nominal 56-volt dc input inverter. The pump-motor assembly will be used to circulate Dow Corning 200 liquid coolant for use in a Brayton cycle space power system. The pump-motor assembly develops a nominal head of 70 psi at 3.7 gpm with an over-all efficiency of 26 percent. The design description, drawings, photographs, reliability results, and developmental and acceptance test results are included.

Self-assembled software and method of overriding software execution

DOEpatents

Bouchard, Ann M.; Osbourn, Gordon C.

2013-01-08

A computer-implemented software self-assembled system and method for providing an external override and monitoring capability to dynamically self-assembling software containing machines that self-assemble execution sequences and data structures. The method provides an external override machine that can be introduced into a system of self-assembling machines while the machines are executing such that the functionality of the executing software can be changed or paused without stopping the code execution and modifying the existing code. Additionally, a monitoring machine can be introduced without stopping code execution that can monitor specified code execution functions by designated machines and communicate the status to an output device.

Zero-g simulation system for therapeutic application

NASA Technical Reports Server (NTRS)

Dane, D. H.

1971-01-01

System aids in therapeutic retraining of damaged muscles or functions as walking support during therapy. Articulated harness assembly contains patient, suspension system supports harness assembly in such a way as to counterbalance exertion of external forces on patient.

Afterburning control of internal combustion engine exhaust gas

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

Nakajima, Y.; Hayashi, Y.; Nagumo, S.I.

1976-08-17

Flow of secondary air into the exhaust system is regulated by diaphragm assembly controlled valves between an air supply and the exhaust system. The diaphragm assemblies respond to vacuum in the intake air system of the engine.

Verification Test of Automated Robotic Assembly of Space Truss Structures

NASA Technical Reports Server (NTRS)

Rhodes, Marvin D.; Will, Ralph W.; Quach, Cuong C.

1995-01-01

A multidisciplinary program has been conducted at the Langley Research Center to develop operational procedures for supervised autonomous assembly of truss structures suitable for large-aperture antennas. The hardware and operations required to assemble a 102-member tetrahedral truss and attach 12 hexagonal panels were developed and evaluated. A brute-force automation approach was used to develop baseline assembly hardware and software techniques. However, as the system matured and operations were proven, upgrades were incorporated and assessed against the baseline test results. These upgrades included the use of distributed microprocessors to control dedicated end-effector operations, machine vision guidance for strut installation, and the use of an expert system-based executive-control program. This paper summarizes the developmental phases of the program, the results of several assembly tests, and a series of proposed enhancements. No problems that would preclude automated in-space assembly or truss structures have been encountered. The test system was developed at a breadboard level and continued development at an enhanced level is warranted.

Mini-Brayton heat source assembly development

NASA Technical Reports Server (NTRS)

Wein, D.; Zimmerman, W. F.

1978-01-01

The work accomplished on the Mini-Brayton Heat Source Assembly program is summarized. Required technologies to design, fabricate and assemble components for a high temperature Heat Source Assembly (HSA) which would generate and transfer the thermal energy for a spaceborne Brayton Isotope Power System (BIPS) were developed.

24 CFR 3285.601 - Field assembly.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Field assembly. 3285.601 Section... § 3285.601 Field assembly. Home manufacturers must provide specific installation instructions for the proper field assembly of manufacturer-supplied and shipped loose ducts, plumbing, and fuel supply system...

24 CFR 3285.601 - Field assembly.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Field assembly. 3285.601 Section... § 3285.601 Field assembly. Home manufacturers must provide specific installation instructions for the proper field assembly of manufacturer-supplied and shipped loose ducts, plumbing, and fuel supply system...

24 CFR 3285.601 - Field assembly.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Field assembly. 3285.601 Section... § 3285.601 Field assembly. Home manufacturers must provide specific installation instructions for the proper field assembly of manufacturer-supplied and shipped loose ducts, plumbing, and fuel supply system...

24 CFR 3285.601 - Field assembly.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Field assembly. 3285.601 Section... § 3285.601 Field assembly. Home manufacturers must provide specific installation instructions for the proper field assembly of manufacturer-supplied and shipped loose ducts, plumbing, and fuel supply system...

Modular Assembly of the Bacterial Large Ribosomal Subunit.

PubMed

Davis, Joseph H; Tan, Yong Zi; Carragher, Bridget; Potter, Clinton S; Lyumkis, Dmitry; Williamson, James R

2016-12-01

The ribosome is a complex macromolecular machine and serves as an ideal system for understanding biological macromolecular assembly. Direct observation of ribosome assembly in vivo is difficult, as few intermediates have been isolated and thoroughly characterized. Herein, we deploy a genetic system to starve cells of an essential ribosomal protein, which results in the accumulation of assembly intermediates that are competent for maturation. Quantitative mass spectrometry and single-particle cryo-electron microscopy reveal 13 distinct intermediates, which were each resolved to ∼4-5 Å resolution and could be placed in an assembly pathway. We find that ribosome biogenesis is a parallel process, that blocks of structured rRNA and proteins assemble cooperatively, and that the entire process is dynamic and can be "re-routed" through different pathways as needed. This work reveals the complex landscape of ribosome assembly in vivo and provides the requisite tools to characterize additional assembly pathways for ribosomes and other macromolecular machines. Copyright © 2016 Elsevier Inc. All rights reserved.

Modular Assembly of the Bacterial Large Ribosomal Subunit

PubMed Central

Davis, Joseph H.; Tan, Yong Zi; Carragher, Bridget; Potter, Clinton S.; Lyumkis, Dmitry; Williamson, James R.

2016-01-01

SUMMARY The ribosome is a complex macromolecular machine and serves as an ideal system for understanding biological macromolecular assembly. Direct observation of ribosome assembly in vivo is difficult, as few intermediates have been isolated and thoroughly characterized. Herein, we deploy a genetic system to starve cells of an essential ribosomal protein, which results in the accumulation of assembly intermediates that are competent for maturation. Quantitative mass spectrometry and single-particle cryo-electron microscopy reveal 13 distinct intermediates, which were each resolved to ~4–5Å resolution and could be placed in an assembly pathway. We find that ribosome biogenesis is a parallel process, that blocks of structured rRNA and proteins assemble cooperatively, and that the entire process is dynamic and can be ‘re-routed’ through different pathways as needed. This work reveals the complex landscape of ribosome assembly in vivo and provides the requisite tools to characterize additional assembly pathways for ribosomes and other macromolecular machines. PMID:27912064

Wind turbine/generator set having a stator cooling system located between stator frame and active coils

DOEpatents

Bevington, Christopher M.; Bywaters, Garrett L.; Coleman, Clint C.; Costin, Daniel P.; Danforth, William L.; Lynch, Jonathan A.; Rolland, Robert H.

2012-11-13

A wind turbine comprising an electrical generator that includes a rotor assembly. A wind rotor that includes a wind rotor hub is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle via a bearing assembly. The wind rotor hub includes an opening having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity inside the wind rotor hub. The spindle is attached to a turret supported by a tower. Each of the spindle, turret and tower has an interior cavity that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

Waste heat recovery system

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

Ernst, Timothy C.; Zigan, James A.

A waste heat recovery system includes a Rankine cycle (RC) circuit having a pump, a boiler, an energy converter, and a condenser fluidly coupled via conduits in that order, to provide additional work. The additional work is fed to an input of a gearbox assembly including a capacity for oil by mechanically coupling to the energy converter to a gear assembly. An interface is positioned between the RC circuit and the gearbox assembly to partially restrict movement of oil present in the gear assembly into the RC circuit and partially restrict movement of working fluid present in the RC circuitmore » into the gear assembly. An oil return line is fluidly connected to at least one of the conduits fluidly coupling the RC components to one another and is operable to return to the gear assembly oil that has moved across the interface from the gear assembly to the RC circuit.« less

Interrogating viral capsid assembly with ion mobility-mass spectrometry

NASA Astrophysics Data System (ADS)

Uetrecht, Charlotte; Barbu, Ioana M.; Shoemaker, Glen K.; van Duijn, Esther; Heck, Albert J. R.

2011-02-01

Most proteins fulfil their function as part of large protein complexes. Surprisingly, little is known about the pathways and regulation of protein assembly. Several viral coat proteins can spontaneously assemble into capsids in vitro with morphologies identical to the native virion and thus resemble ideal model systems for studying protein complex formation. Even for these systems, the mechanism for self-assembly is still poorly understood, although it is generally thought that smaller oligomeric structures form key intermediates. This assembly nucleus and larger viral assembly intermediates are typically low abundant and difficult to monitor. Here, we characterised small oligomers of Hepatitis B virus (HBV) and norovirus under equilibrium conditions using native ion mobility mass spectrometry. This data in conjunction with computational modelling enabled us to elucidate structural features of these oligomers. Instead of more globular shapes, the intermediates exhibit sheet-like structures suggesting that they are assembly competent. We propose pathways for the formation of both capsids.

Intelligent electrical harness connector assembly using Bell Helicopter Textron's 'Wire Harness Automated Manufacturing System'

NASA Astrophysics Data System (ADS)

Springer, D. W.

Bell Helicopter Textron, Incorporated (BHTI) installed two Digital Equipment Corporation PDP-11 computers and an American Can Inc. Ink Jet printer in 1980 as the cornerstone of the Wire Harness Automated Manufacturing System (WHAMS). WHAMS is based upon the electrical assembly philosophy of continuous filament harness forming. This installation provided BHTI with a 3 to 1 return-on-investment by reducing wire and cable identification cycle time by 80 percent and harness forming, on dedicated layout tooling, by 40 percent. Yet, this improvement in harness forming created a bottle neck in connector assembly. To remove this bottle neck, BHTI has installed a prototype connector assembly cell that integrates the WHAMS' data base and innovative computer technologies to cut harness connector assembly cycle time. This novel connector assembly cell uses voice recognition, laser identification, and animated computer graphics to help the electrician in the correct assembly of harness connectors.

Combustion Stability of the Gas Generator Assembly from J-2X Engine E10001 and Powerpack Tests

NASA Technical Reports Server (NTRS)

Hulka, J. R.; Kenny, R. L.; Casiano, M. J.

2013-01-01

Testing of a powerpack configuration (turbomachinery and gas generator assembly) and the first complete engine system of the liquid oxygen/liquid hydrogen propellant J-2X rocket engine have been completed at the NASA Stennis Space Center. The combustion stability characteristics of the gas generator assemblies on these two systems are of interest for reporting since considerable effort was expended to eliminate combustion instability during early development of the gas generator assembly with workhorse hardware. Comparing the final workhorse gas generator assembly development test data to the powerpack and engine system test data provides an opportunity to investigate how the nearly identical configurations of gas generator assemblies operate with two very different propellant supply systems one the autonomous pressure-fed test configuration on the workhorse development test stand, the other the pump-fed configurations on the powerpack and engine systems. The development of the gas generator assembly and the elimination of the combustion instability on the pressure-fed workhorse test stand have been reported extensively in the two previous Liquid Propulsion Subcommittee meetings 1-7. The powerpack and engine system testing have been conducted from mid-2011 through 2012. All tests of the powerpack and engine system gas generator systems to date have been stable. However, measureable dynamic behavior, similar to that observed on the pressure-fed test stand and reported in Ref. [6] and attributed to an injection-coupled response, has appeared in both powerpack and engine system tests. As discussed in Ref. [6], these injection-coupled responses are influenced by the interaction of the combustion chamber with a branch pipe in the hot gas duct that supplies gaseous helium to pre-spin the turbine during the start transient. This paper presents the powerpack and engine system gas generator test data, compares these data to the development test data, and provides additional combustion stability analyses of the configurations.

A modular assembly method of a feed and thruster system for Cubesats

NASA Astrophysics Data System (ADS)

Louwerse, Marcus; Jansen, Henri; Elwenspoek, Miko

2010-11-01

A modular assembly method for devices based on micro system technology is presented. The assembly method forms the foundation for a miniaturized feed and thruster system as part of a micro propulsion unit working as a simple blow-down system of a rocket engine. The micro rocket is designed to be used for constellation maintenance of Cubesats, which measure 10 × 10 × 10 cm and have a mass less than 1 kg. The feed and thruster system contains an active valve, control electronics, a particle filter and an axisymmetric converging-diverging nozzle, all fabricated as separate modules. A novel method is used to integrate these modules by placing them on or in a glass tube package. The assembly method is shown to be a valid method but the valve module needs to be improved considerably.

Acousto-fluidic system assisting in-liquid self-assembly of microcomponents

NASA Astrophysics Data System (ADS)

Goldowsky, J.; Mastrangeli, M.; Jacot-Descombes, L.; Gullo, M. R.; Mermoud, G.; Brugger, J.; Martinoli, A.; Nelson, B. J.; Knapp, Helmut F.

2013-12-01

In this paper, we present the theoretical background, design, fabrication and characterization of a micromachined chamber assisting the fluidic self-assembly of micro-electro-mechanical systems in a bulk liquid. Exploiting bubble-induced acoustic microstreaming, several structurally-robust driving modes are excited inside the chamber. The modes promote the controlled aggregation and disaggregation of microcomponents relying on strong and reproducible fluid mixing effects achieved even at low Reynolds numbers. The functionality of the microfluidic chamber is demonstrated through the fast and repeatable geometrical pairing and subsequent unpairing of polymeric microcylinders. Relying only on drag and radiation forces and on the natural hydrophobicity of SU-8 in aqueous solutions, assembly yields of approximately 50% are achieved in no longer than ten seconds of agitation. The system can stochastically control the assembly process and significantly reduce the time-to-assembly of building blocks.

Development of simulation approach for two-dimensional chiral molecular self-assembly driven by hydrogen bond at the liquid/solid interface

NASA Astrophysics Data System (ADS)

Qin, Yuan; Yao, Man; Hao, Ce; Wan, Lijun; Wang, Yunhe; Chen, Ting; Wang, Dong; Wang, Xudong; Chen, Yonggang

2017-09-01

Two-dimensional (2D) chiral self-assembly system of 5-(benzyloxy)-isophthalic acid derivative/(S)-(+)-2-octanol/highly oriented pyrolytic graphite was studied. A combined density functional theory/molecular mechanics/molecular dynamics (DFT/MM/MD) approach for system of 2D chiral molecular self-assembly driven by hydrogen bond at the liquid/solid interface was thus proposed. Structural models of the chiral assembly were built on the basis of scanning tunneling microscopy (STM) images and simplified for DFT geometry optimization. Merck Molecular Force Field (MMFF) was singled out as the suitable force field by comparing the optimized configurations of MM and DFT. MM and MD simulations for hexagonal unit model which better represented the 2D assemble network were then preformed with MMFF. The adhesion energy, evolution of self-assembly process and characteristic parameters of hydrogen bond were obtained and analyzed. According to the above simulation, the stabilities of the clockwise and counterclockwise enantiomorphous networks were evaluated. The calculational results were supported by STM observations and the feasibility of the simulation method was confirmed by two other systems in the presence of chiral co-absorbers (R)-(-)-2-octanol and achiral co-absorbers 1-octanol. This theoretical simulation method assesses the stability trend of 2D enantiomorphous assemblies with atomic scale and can be applied to the similar hydrogen bond driven 2D chirality of molecular self-assembly system.

Dynamics of dissipative self-assembly of particles interacting through oscillatory forces

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

Tagliazucchi, M.; Szleifer, I.

Dissipative self-assembly is the formation of ordered structures far from equilibrium, which continuously uptake energy and dissipate it into the environment. Due to its dynamical nature, dissipative self-assembly can lead to new phenomena and possibilities of self-organization that are unavailable to equilibrium systems. Understanding the dynamics of dissipative self-assembly is required in order to direct the assembly to structures of interest. In the present work, Brownian dynamics simulations and analytical theory were used to study the dynamics of self-assembly of a mixture of particles coated with weak acids and bases under continuous oscillations of the pH. The pH of themore » system modulates the charge of the particles and, therefore, the interparticle forces oscillate in time. This system produces a variety of self-assembled structures, including colloidal molecules, fibers and different types of crystalline lattices. The most important conclusions of our study are: (i) in the limit of fast oscillations, the whole dynamics (and not only those at the non-equilibrium steady state) of a system of particles interacting through time-oscillating interparticle forces can be described by an effective potential that is the time average of the time-dependent potential over one oscillation period; (ii) the oscillation period is critical to determine the order of the system. In some cases the order is favored by very fast oscillations while in others small oscillation frequencies increase the order. In the latter case, it is shown that slow oscillations remove kinetic traps and, thus, allow the system to evolve towards the most stable non-equilibrium steady state.« less

Variation simulation for compliant sheet metal assemblies with applications

NASA Astrophysics Data System (ADS)

Long, Yufeng

Sheet metals are widely used in discrete products, such as automobiles, aircraft, furniture and electronics appliances, due to their good manufacturability and low cost. A typical automotive body assembly consists of more than 300 parts welded together in more than 200 assembly fixture stations. Such an assembly system is usually quite complex, and takes a long time to develop. As the automotive customer demands products of increasing quality in a shorter time, engineers in automotive industry turn to computer-aided engineering (CAE) tools for help. Computers are an invaluable resource for engineers, not only to simplify and automate the design process, but also to share design specifications with manufacturing groups so that production systems can be tooled up quickly and efficiently. Therefore, it is beneficial to develop computerized simulation and evaluation tools for development of automotive body assembly systems. It is a well-known fact that assembly architectures (joints, fixtures, and assembly lines) have a profound impact on dimensional quality of compliant sheet metal assemblies. To evaluate sheet metal assembly architectures, a special dimensional analysis tool need be developed for predicting dimensional variation of the assembly. Then, the corresponding systematic tools can be established to help engineers select the assembly architectures. In this dissertation, a unified variation model is developed to predict variation in compliant sheet metal assemblies by considering fixture-induced rigid-body motion, deformation and springback. Based on the unified variation model, variation propagation models in multiple assembly stations with various configurations are established. To evaluate the dimensional capability of assembly architectures, quantitative indices are proposed based on the sensitivity matrix, which are independent of the variation level of the process. Examples are given to demonstrate their applications in selecting robust assembly architectures, and some useful guidelines for selection of assembly architectures are summarized. In addition, to enhance the fault diagnosis, a systematic methodology is proposed for selection of measurement configurations. Specifically, principles involved in selecting measurements are generalized first; then, the corresponding quantitative indices are developed to evaluate the measurement configurations, and finally, examples are present.

Cryogenic Fiber Optic Assemblies for Spaceflight Environments: Design, Manufacturing, Testing, and Integration

NASA Technical Reports Server (NTRS)

Thomes, W. Joe; Ott, Melanie N.; Chuska, Richard; Switzer, Robert; Onuma, Eleanya; Blair, Diana; Frese, Erich; Matyseck, Marc

2016-01-01

Fiber optic assemblies have been used on spaceflight missions for many years as an enabling technology for routing, transmitting, and detecting optical signals. Due to the overwhelming success of NASA in implementing fiber optic assemblies on spaceflight science-based instruments, system scientists increasingly request fibers that perform in extreme environments while still maintaining very high optical transmission, stability, and reliability. Many new applications require fiber optic assemblies that will operate down to cryogenic temperatures as low as 20 Kelvin. In order for the fiber assemblies to operate with little loss in optical throughput at these extreme temperatures requires a system level approach all the way from how the fiber assembly is manufactured to how it is held, routed, and integrated. The NASA Goddard Code 562 Photonics Group has been designing, manufacturing, testing, and integrating fiber optics for spaceflight and other high reliability applications for nearly 20 years. Design techniques and lessons learned over the years are consistently applied to developing new fiber optic assemblies that meet these demanding environments. System level trades, fiber assembly design methods, manufacturing, testing, and integration will be discussed. Specific recent examples of ground support equipment for the James Webb Space Telescope (JWST); the Ice, Cloud and Land Elevation Satellite-2 (ICESat-2); and others will be included.

A unified convention for biological assemblies with helical symmetry

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

Tsai, Chung-Jung, E-mail: tsaic@mail.nih.gov; Nussinov, Ruth; Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978

A new representation of helical structure by four parameters, [n{sub 1}, n{sub 2}, twist, rise], is able to generate an entire helical construct from asymmetric units, including cases of helical assembly with a seam. Assemblies with helical symmetry can be conveniently formulated in many distinct ways. Here, a new convention is presented which unifies the two most commonly used helical systems for generating helical assemblies from asymmetric units determined by X-ray fibre diffraction and EM imaging. A helical assembly is viewed as being composed of identical repetitive units in a one- or two-dimensional lattice, named 1-D and 2-D helical systems,more » respectively. The unification suggests that a new helical description with only four parameters [n{sub 1}, n{sub 2}, twist, rise], which is called the augmented 1-D helical system, can generate the complete set of helical arrangements, including coverage of helical discontinuities (seams). A unified four-parameter characterization implies similar parameters for similar assemblies, can eliminate errors in reproducing structures of helical assemblies and facilitates the generation of polymorphic ensembles from helical atomic models or EM density maps. Further, guidelines are provided for such a unique description that reflects the structural signature of an assembly, as well as rules for manipulating the helical symmetry presentation.« less

Cryogenic fiber optic assemblies for spaceflight environments: design, manufacturing, testing, and integration

NASA Astrophysics Data System (ADS)

Thomes, W. Joe; Ott, Melanie N.; Chuska, Richard; Switzer, Robert; Onuma, Eleanya; Blair, Diana; Frese, Erich; Matyseck, Marc

2016-09-01

Fiber optic assemblies have been used on spaceflight missions for many years as an enabling technology for routing, transmitting, and detecting optical signals. Due to the overwhelming success of NASA in implementing fiber optic assemblies on spaceflight science-based instruments, system scientists increasingly request fibers that perform in extreme environments while still maintaining very high optical transmission, stability, and reliability. Many new applications require fiber optic assemblies that will operate down to cryogenic temperatures as low as 20 Kelvin. In order for the fiber assemblies to operate with little loss in optical throughput at these extreme temperatures requires a system level approach all the way from how the fiber assembly is manufactured to how it is held, routed, and integrated. The NASA Goddard Code 562 Photonics Group has been designing, manufacturing, testing, and integrating fiber optics for spaceflight and other high reliability applications for nearly 20 years. Design techniques and lessons learned over the years are consistently applied to developing new fiber optic assemblies that meet these demanding environments. System level trades, fiber assembly design methods, manufacturing, testing, and integration will be discussed. Specific recent examples of ground support equipment for the James Webb Space Telescope (JWST); the Ice, Cloud and Land Elevation Satellite-2 (ICESat- 2); and others will be included.

System and method for injecting fuel

DOEpatents

Uhm, Jong Ho; Johnson, Thomas Edward

2012-12-04

According to various embodiments, a system includes a staggered multi-nozzle assembly. The staggered multi-nozzle assembly includes a first fuel nozzle having a first axis and a first flow path extending to a first downstream end portion, wherein the first fuel nozzle has a first non-circular perimeter at the first downstream end portion. The staggered multi-nozzle assembly also includes a second fuel nozzle having a second axis and a second flow path extending to a second downstream end portion, wherein the first and second downstream end portions are axially offset from one another relative to the first and second axes. The staggered multi-nozzle assembly further includes a cap member disposed circumferentially about at least the first and second fuel nozzles to assemble the staggered multi-nozzle assembly.

Status of the Regenerative ECLSS Water Recovery System

NASA Technical Reports Server (NTRS)

Carter, Donald Layne

2009-01-01

NASA has completed the delivery of the regenerative Water Recovery System (WRS) for the International Space Station (ISS). The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the final effort to deliver the hardware to the Kennedy Space Center for launch on STS-126, the on-orbit status as of April 2009, and describes some of the technical challenges encountered and lessons learned over the past year.

Root-Contact/Pressure-Plate Assembly For Hydroponic System

NASA Technical Reports Server (NTRS)

Morris, Carlton E.; Loretan, Philip A.; Bonsi, Conrad K.; Hill, Walter A.

1994-01-01

Hydroponic system includes growth channels equipped with rootcontact/pressure-plate assemblies. Pump and associated plumbing circulate nutrient liquid from reservoir, along bottom of growth channels, and back to reservoir. Root-contact/pressure-plate assembly in each growth channel stimulates growth of roots by applying mild contact pressure. Flat plate and plate connectors, together constitute pressure plate, free to move upward to accommodate growth of roots. System used for growing sweetpotatoes and possibly other tuber and root crops.

General view of the Space Shuttle Main Engine (SSME) assembly ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of the Space Shuttle Main Engine (SSME) assembly with the expansion nozzle removed and resting on a cushioned mat on the floor of the SSME Processing Facility. The most prominent features in this view are the Low-pressure Fuel Turbopump discharge Duct looping from the upper left side of the engine assembly to the lower left side of the assembly, the Low-Pressure Oxidizer Turbopump (LPOTP) is on the upper left of the assembly in this view and the LPOTP Discharge Duct loops from the upper left to upper right. The sphere in the middle right side of the assembly in this view is the POGO System Accumulator , the partial sphere to its left and slightly more toward the center of the assembly is the Heat Exchanger on the Oxidizer Preburner side of the Hot Gas Manifold, beneath that is the High-Pressure Oxidizer Turbopump (HPOTP) and the HPOTP Discharge duct loops from the pump around to the lower left of the assembly. The Pneumatic Control Assembly is in the approximate center of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Discrete State Change Model of Manufacturing Quality to Aid Assembly Process Design

NASA Astrophysics Data System (ADS)

Koga, Tsuyoshi; Aoyama, Kazuhiro

This paper proposes a representation model of the quality state change in an assembly process that can be used in a computer-aided process design system. In order to formalize the state change of the manufacturing quality in the assembly process, the functions, operations, and quality changes in the assembly process are represented as a network model that can simulate discrete events. This paper also develops a design method for the assembly process. The design method calculates the space of quality state change and outputs a better assembly process (better operations and better sequences) that can be used to obtain the intended quality state of the final product. A computational redesigning algorithm of the assembly process that considers the manufacturing quality is developed. The proposed method can be used to design an improved manufacturing process by simulating the quality state change. A prototype system for planning an assembly process is implemented and applied to the design of an auto-breaker assembly process. The result of the design example indicates that the proposed assembly process planning method outputs a better manufacturing scenario based on the simulation of the quality state change.

Viewfinder/tracking system for Skylab

NASA Technical Reports Server (NTRS)

Casey, W. L.

1975-01-01

Basic component of system is infrared spectrometer designed for manual target acquisition, pointing and tracking, and data-take initiation. System incorporates three main subsystems which include: (1) viewfinder telescope, (2) control panel and electronics assembly, and (3) IR-spectrometer case assembly.

Characterisation of minimalist co-assembled fluorenylmethyloxycarbonyl self-assembling peptide systems for presentation of multiple bioactive peptides.

PubMed

Horgan, Conor C; Rodriguez, Alexandra L; Li, Rui; Bruggeman, Kiara F; Stupka, Nicole; Raynes, Jared K; Day, Li; White, John W; Williams, Richard J; Nisbet, David R

2016-07-01

The nanofibrillar structures that underpin self-assembling peptide (SAP) hydrogels offer great potential for the development of finely tuned cellular microenvironments suitable for tissue engineering. However, biofunctionalisation without disruption of the assembly remains a key issue. SAPS present the peptide sequence within their structure, and studies to date have typically focused on including a single biological motif, resulting in chemically and biologically homogenous scaffolds. This limits the utility of these systems, as they cannot effectively mimic the complexity of the multicomponent extracellular matrix (ECM). In this work, we demonstrate the first successful co-assembly of two biologically active SAPs to form a coassembled scaffold of distinct two-component nanofibrils, and demonstrate that this approach is more bioactive than either of the individual systems alone. Here, we use two bioinspired SAPs from two key ECM proteins: Fmoc-FRGDF containing the RGD sequence from fibronectin and Fmoc-DIKVAV containing the IKVAV sequence from laminin. Our results demonstrate that these SAPs are able to co-assemble to form stable hybrid nanofibres containing dual epitopes. Comparison of the co-assembled SAP system to the individual SAP hydrogels and to a mixed system (composed of the two hydrogels mixed together post-assembly) demonstrates its superior stable, transparent, shear-thinning hydrogels at biological pH, ideal characteristics for tissue engineering applications. Importantly, we show that only the coassembled hydrogel is able to induce in vitro multinucleate myotube formation with C2C12 cells. This work illustrates the importance of tissue engineering scaffold functionalisation and the need to develop increasingly advanced multicomponent systems for effective ECM mimicry. Successful control of stem cell fate in tissue engineering applications requires the use of sophisticated scaffolds that deliver biological signals to guide growth and differentiation. The complexity of such processes necessitates the presentation of multiple signals in order to effectively mimic the native extracellular matrix (ECM). Here, we establish the use of two biofunctional, minimalist self-assembling peptides (SAPs) to construct the first co-assembled SAP scaffold. Our work characterises this construct, demonstrating that the physical, chemical, and biological properties of the peptides are maintained during the co-assembly process. Importantly, the coassembled system demonstrates superior biological performance relative to the individual SAPs, highlighting the importance of complex ECM mimicry. This work has important implications for future tissue engineering studies. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Apparatus for observing a hostile environment

DOEpatents

Nance, Thomas A.; Boylston, Micah L.; Robinson, Casandra W.; Sexton, William C.; Heckendorn, Frank M.

2000-01-01

An apparatus is provided for observing a hostile environment, comprising a housing and a camera capable of insertion within the housing. The housing is a double wall assembly with an inner and outer wall with an hermetically sealed chamber therebetween. A housing for an optical system used to observe a hostile environment is provided, comprising a transparent, double wall assembly. The double wall assembly has an inner wall and an outer wall with an hermetically sealed chamber therebetween. The double wall assembly has an opening and a void area in communication with the opening. The void area of the housing is adapted to accommodate the optical system within said void area. An apparatus for protecting an optical system used to observe a hostile environment is provided comprising a housing; a tube positioned within the housing; and a base for supporting the housing and the tube. The housing comprises a double wall assembly having an inner wall and an outerwall with an hermetically sealed chamber therebetween. The tube is adapted to house the optical system therein.

The development of alignment turning system for precision len cells

NASA Astrophysics Data System (ADS)

Huang, Chien-Yao; Ho, Cheng-Fang; Wang, Jung-Hsing; Chung, Chien-Kai; Chen, Jun-Cheng; Chang, Keng-Shou; Kuo, Ching-Hsiang; Hsu, Wei-Yao; Chen, Fong-Zhi

2017-08-01

In general, the drop-in and cell-mounted assembly are used for standard and high performance optical system respectively. The optical performance is limited by the residual centration error and position accuracy of the conventional assembly. Recently, the poker chip assembly with high precision lens barrels that can overcome the limitation of conventional assembly is widely applied to ultra-high performance optical system. ITRC also develops the poker chip assembly solution for high numerical aperture objective lenses and lithography projection lenses. In order to achieve high precision lens cell for poker chip assembly, an alignment turning system (ATS) is developed. The ATS includes measurement, alignment and turning modules. The measurement module including a non-contact displacement sensor and an autocollimator can measure centration errors of the top and the bottom surface of a lens respectively. The alignment module comprising tilt and translation stages can align the optical axis of the lens to the rotating axis of the vertical lathe. The key specifications of the ATS are maximum lens diameter, 400mm, and radial and axial runout of the rotary table < 2 μm. The cutting performances of the ATS are surface roughness Ra < 1 μm, flatness < 2 μm, and parallelism < 5 μm. After measurement, alignment and turning processes on our ATS, the centration error of a lens cell with 200mm in diameter can be controlled in 10 arcsec. This paper also presents the thermal expansion of the hydrostatic rotating table. A poker chip assembly lens cell with three sub-cells is accomplished with average transmission centration error in 12.45 arcsec by fresh technicians. The results show that ATS can achieve high assembly efficiency for precision optical systems.

Microfabricated field calibration assembly for analytical instruments

DOEpatents

Robinson, Alex L [Albuquerque, NM; Manginell, Ronald P [Albuquerque, NM; Moorman, Matthew W [Albuquerque, NM; Rodacy, Philip J [Albuquerque, NM; Simonson, Robert J [Cedar Crest, NM

2011-03-29

A microfabricated field calibration assembly for use in calibrating analytical instruments and sensor systems. The assembly comprises a circuit board comprising one or more resistively heatable microbridge elements, an interface device that enables addressable heating of the microbridge elements, and, in some embodiments, a means for positioning the circuit board within an inlet structure of an analytical instrument or sensor system.

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

West, W.S.

Progress during the period includes completion of the SNAP 7C system tests, completion of safety analysis for the SNAP 7A and C systems, assembly and initial testing of SNAP 7A, assembly of a modified reliability model, and assembly of a 10-W generator. Other activities include completion of thermal and safety analyses for SNAP 7B and D generators and fuel processing for these generators. (J.R.D.)

Using the ISS as a testbed to prepare for the next generation of space-based telescopes

NASA Astrophysics Data System (ADS)

Postman, Marc; Sparks, William B.; Liu, Fengchuan; Ess, Kim; Green, Joseph; Carpenter, Kenneth G.; Thronson, Harley; Goullioud, Renaud

2012-09-01

The infrastructure available on the ISS provides a unique opportunity to develop the technologies necessary to assemble large space telescopes. Assembling telescopes in space is a game-changing approach to space astronomy. Using the ISS as a testbed enables a concentration of resources on reducing the technical risks associated with integrating the technologies, such as laser metrology and wavefront sensing and control (WFS&C), with the robotic assembly of major components including very light-weight primary and secondary mirrors and the alignment of the optical elements to a diffraction-limited optical system in space. The capability to assemble the optical system and remove and replace components via the existing ISS robotic systems such as the Special Purpose Dexterous Manipulator (SPDM), or by the ISS Flight Crew, allows for future experimentation as well as repair if necessary. In 2015, first light will be obtained by the Optical Testbed and Integration on ISS eXperiment (OpTIIX), a small 1.5-meter optical telescope assembled on the ISS. The primary objectives of OpTIIX include demonstrating telescope assembly technologies and end-to-end optical system technologies that will advance future large optical telescopes.

User assembly and servicing system for Space Station, an evolving architecture approach

NASA Technical Reports Server (NTRS)

Lavigna, Thomas A.; Cline, Helmut P.

1988-01-01

On-orbit assembly and servicing of a variety of scientific and applications hardware systems is expected to be one of the Space Station's primary functions. The hardware to be serviced will include the attached payloads resident on the Space Station, the free-flying satellites and co-orbiting platforms brought to the Space Station, and the polar orbiting platforms. The requirements for assembly and servicing such a broad spectrum of missions have led to the development of an Assembly and Servicing System Architecture that is composed of a complex array of support elements. This array is comprised of US elements, both Space Station and non-Space Station, and elements provided by Canada to the Space Station Program. For any given servicing or assembly mission, the necessary support elements will be employed in an integrated manner to satisfy the mission-specific needs. The structure of the User Assembly and Servicing System Architecture and the manner in which it will evolved throughout the duration of the phased Space Station Program are discussed. Particular emphasis will be placed upon the requirements to be accommodated in each phase, and the development of a logical progression of capabilities to meet these requirements.

Assembled modules technology for site-specific prolonged delivery of norfloxacin.

PubMed

Oliveira, Paulo Renato; Bernardi, Larissa Sakis; Strusi, Orazio Luca; Mercuri, Salvatore; Segatto Silva, Marcos A; Colombo, Paolo; Sonvico, Fabio

2011-02-28

The aim of this research was to design and study norfloxacin (NFX) release in floating conditions from compressed hydrophilic matrices of hydroxypropylmethylcellulose (HPMC) or poly(ethylene oxide) (PEO). Module assembling technology for drug delivery system manufacturing was used. Two differently cylindrical base curved matrix/modules, identified as female and male, were assembled in void configuration by friction interlocking their concave bases obtaining a floating release system. Drug release and floatation behavior of this assembly was investigated. Due to the higher surface area exposed to the release medium, faster release was observed for individual modules compared to their assembled configuration, independently on the polymer used and concentration. The release curves analyzed using the Korsmeyer exponential equation and Peppas & Sahlin binomial equation showed that the drug release was controlled both by drug diffusion and polymer relaxation or erosion mechanisms. However, convective transport was predominant with PEO and at low content of polymers. NFX release from PEO polymeric matrix was more erosion dependent than HPMC. The assembled systems were able to float in vitro for up to 240min, indicating that this drug delivery system of norfloxacin could provide gastro-retentive site-specific release for increasing norfloxacin bioavailability. Copyright © 2010. Published by Elsevier B.V.

An incomplete assembly with thresholding algorithm for systems of reaction-diffusion equations in three space dimensions IAT for reaction-diffusion systems

NASA Astrophysics Data System (ADS)

Moore, Peter K.

2003-07-01

Solving systems of reaction-diffusion equations in three space dimensions can be prohibitively expensive both in terms of storage and CPU time. Herein, I present a new incomplete assembly procedure that is designed to reduce storage requirements. Incomplete assembly is analogous to incomplete factorization in that only a fixed number of nonzero entries are stored per row and a drop tolerance is used to discard small values. The algorithm is incorporated in a finite element method-of-lines code and tested on a set of reaction-diffusion systems. The effect of incomplete assembly on CPU time and storage and on the performance of the temporal integrator DASPK, algebraic solver GMRES and preconditioner ILUT is studied.

Continuous pressure letdown system

DOEpatents

Sprouse, Kenneth M.; Matthews, David R.; Langowski, Terry

2010-06-08

A continuous pressure letdown system connected to a hopper decreases a pressure of a 2-phase (gas and solid) dusty gas stream flowing through the system. The system includes a discharge line for receiving the dusty gas from the hopper, a valve, a cascade nozzle assembly positioned downstream of the discharge line, a purge ring, an inert gas supply connected to the purge ring, an inert gas throttle, and a filter. The valve connects the hopper to the discharge line and controls introduction of the dusty gas stream into the discharge line. The purge ring is connected between the discharge line and the cascade nozzle assembly. The inert gas throttle controls a flow rate of an inert gas into the cascade nozzle assembly. The filter is connected downstream of the cascade nozzle assembly.

New image-stabilizing system

NASA Astrophysics Data System (ADS)

Zhao, Yuejin

1996-06-01

In this paper, a new method for image stabilization with a three-axis image- stabilizing reflecting prism assembly is presented, and the principle of image stabilization in this prism assembly, formulae for image stabilization and working formulae with an approximation up to the third power are given in detail. In this image-stabilizing system, a single chip microcomputer is used to calculate value of compensating angles and thus to control the prism assembly. Two gyroscopes act as sensors from which information of angular perturbation is obtained, three stepping motors drive the prism assembly to compensate for the movement of image produced by angular perturbation. The image-stabilizing device so established is a multifold system which involves optics, mechanics, electronics and computer.

Development of cable drive systems for an automated assembly project

NASA Technical Reports Server (NTRS)

Monroe, Charles A., Jr.

1990-01-01

In a robotic assembly project, a method was needed to accurately position a robot and a structure which the robot was to assemble. The requirements for high precision and relatively long travel distances dictated the use of cable drive systems. The design of the mechanisms used in translating the robot and in rotating the assembly under construction is discussed. The design criteria are discussed, and the effect of particular requirements on the design is noted. Finally, the measured performance of the completed mechanism is compared with design requirements.

Rodded shutdown system for a nuclear reactor

DOEpatents

Golden, Martin P.; Govi, Aldo R.

1978-01-01

A top mounted nuclear reactor diverse rodded shutdown system utilizing gas fed into a pressure bearing bellows region sealed at the upper extremity to an armature. The armature is attached to a neutron absorber assembly by a series of shafts and connecting means. The armature is held in an uppermost position by an electromagnet assembly or by pressurized gas in a second embodiment. Deenergizing the electromagnet assembly, or venting the pressurized gas, causes the armature to fall by the force of gravity, thereby lowering the attached absorber assembly into the reactor core.

Automatic box loader

DOEpatents

Eldridge, Harry H.; Jones, Robert A.; Lindner, Gordon M.; Hight, Paul H.

1976-01-01

This invention relates to a system for repetitively forming an assembly consisting of a single layer of tubes and a row of ferromagnetic armatures underlying the same, electromagnetically conveying the resulting assembly to a position overlying a storage box, and depositing the assembly in the box. The system includes means for simultaneously depositing a row of the armatures on the inclined surface of a tube retainer. Tubes then are rolled down the surface to form a single tube layer bridging the armatures. A magnet assembly carrying electromagnets respectively aligned with the armatures is advanced close to the tube layer, and in the course of this advance is angularly displaced to bring the pole pieces of the electromagnets into parallelism with the tube layer. The magnets then are energized to pick up the assembly. The loaded magnet assembly is retracted to a position overlying the box, and during this retraction is again displaced to bring the pole pieces of the electromagnets into a horizontal plane. Means are provided for inserting the loaded electromagnets in the box and then de-energizing the electromagnets to deposit the assembly therein. The system accomplishes the boxing of fragile tubes at relatively high rates. Because the tubes are boxed as separated uniform layers, subsequent unloading operations are facilitated.

Manufacturing Laboratory for Next Generation Engineers

DTIC Science & Technology

2013-12-16

automated CNC machines, rapid prototype systems, robotic assembly systems, metrology , and non-traditional systems such as a waterjet cutter, EDM machine...CNC machines, rapid prototype systems, robotic assembly systems, metrology , and non-traditional systems such as a waterjet cutter, EDM machine, plasma...System Metrology and Quality Control Equipment - This area already had a CMM and other well known quality control instrumentation. It has been enhanced

3-D Packaging: A Technology Review

NASA Technical Reports Server (NTRS)

Strickland, Mark; Johnson, R. Wayne; Gerke, David

2005-01-01

Traditional electronics are assembled as a planar arrangement of components on a printed circuit board (PCB) or other type of substrate. These planar assemblies may then be plugged into a motherboard or card cage creating a volume of electronics. This architecture is common in many military and space electronic systems as well as large computer and telecommunications systems and industrial electronics. The individual PCB assemblies can be replaced if defective or for system upgrade. Some applications are constrained by the volume or the shape of the system and are not compatible with the motherboard or card cage architecture. Examples include missiles, camcorders, and digital cameras. In these systems, planar rigid-flex substrates are folded to create complex 3-D shapes. The flex circuit serves the role of motherboard, providing interconnection between the rigid boards. An example of a planar rigid - flex assembly prior to folding is shown. In both architectures, the interconnection is effectively 2-D.

Multicomponent self-assembly as a tool to harness new properties from peptides and proteins in material design.

PubMed

Okesola, Babatunde O; Mata, Alvaro

2018-05-21

Nature is enriched with a wide variety of complex, synergistic, and highly functional protein-based multicomponent assemblies. As such, nature has served as a source of inspiration for using multicomponent self-assembly as a platform to create highly ordered, complex, and dynamic protein and peptide-based nanostructures. Such an assembly system relies on the initial interaction of distinct individual building blocks leading to the formation of a complex that subsequently assembles into supramolecular architectures. This approach not only serves as a powerful platform for gaining insight into how proteins co-assemble in nature but also offers huge opportunities to harness new properties not inherent in the individual building blocks. In the past decades, various multicomponent self-assembly strategies have been used to extract synergistic properties from proteins and peptides. This review highlights the updates in the field of multicomponent self-assembly of proteins and peptides and summarizes various strategies, including covalent conjugation, ligand-receptor interactions, templated/directed assembly and non-specific co-assembly, for driving the self-assembly of multiple proteins and peptide-based building blocks into functional materials. In particular, we focus on peptide- or protein-containing multicomponent systems that, upon self-assembly, enable the emergence of new properties or phenomena. The ultimate goal of this review is to highlight the importance of multicomponent self-assembly in protein and peptide engineering, and to advocate its growth in the fields of materials science and nanotechnology.

30 CFR 27.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... MINING PRODUCTS METHANE-MONITORING SYSTEMS General Provisions § 27.2 Definitions. As used in this part... designs, manufactures, or assembles and that seeks certification or preliminary testing of a methane-monitoring system or component. (c) Methane-monitoring system means a complete assembly of one or more...

Self-assembly of hierarchically ordered structures in DNA nanotube systems

NASA Astrophysics Data System (ADS)

Glaser, Martin; Schnauß, Jörg; Tschirner, Teresa; Schmidt, B. U. Sebastian; Moebius-Winkler, Maximilian; Käs, Josef A.; Smith, David M.

2016-05-01

The self-assembly of molecular and macromolecular building blocks into organized patterns is a complex process found in diverse systems over a wide range of size and time scales. The formation of star- or aster-like configurations, for example, is a common characteristic in solutions of polymers or other molecules containing multi-scaled, hierarchical assembly processes. This is a recurring phenomenon in numerous pattern-forming systems ranging from cellular constructs to solutions of ferromagnetic colloids or synthetic plastics. To date, however, it has not been possible to systematically parameterize structural properties of the constituent components in order to study their influence on assembled states. Here, we circumvent this limitation by using DNA nanotubes with programmable mechanical properties as our basic building blocks. A small set of DNA oligonucleotides can be chosen to hybridize into micron-length DNA nanotubes with a well-defined circumference and stiffness. The self-assembly of these nanotubes to hierarchically ordered structures is driven by depletion forces caused by the presence of polyethylene glycol. This trait allowed us to investigate self-assembly effects while maintaining a complete decoupling of density, self-association or bundling strength, and stiffness of the nanotubes. Our findings show diverse ranges of emerging structures including heterogeneous networks, aster-like structures, and densely bundled needle-like structures, which compare to configurations found in many other systems. These show a strong dependence not only on concentration and bundling strength, but also on the underlying mechanical properties of the nanotubes. Similar network architectures to those caused by depletion forces in the low-density regime are obtained when an alternative hybridization-based bundling mechanism is employed to induce self-assembly in an isotropic network of pre-formed DNA nanotubes. This emphasizes the universal effect inevitable attractive forces in crowded environments have on systems of self-assembling soft matter, which should be considered for macromolecular structures applied in crowded systems such as cells.

Proceedings of the Electronics Manufacturing Seminar (14th Annual) Held in China Lake, California on 21-22 February 1990

DTIC Science & Technology

1990-02-01

Aging effects Aging of metalic surfaces Aqueous cleaning Circuit- card assembly Cleanability Closed-loop soldering Conformal coating Defect...5 Standard Electronic Circuit Card Assembly System ....................................... 7 Douglas Green Lockheed-Sanders Corp. Nashua, New...Facility Naval Weapons Center NAVIRSA Detachment 5 NWC TP 7066 EMPF TR 0010 STANDARD ELECTRONIC CIRCUTT CARD ASSEMBLY SYSTEM (SECAS PROJECT) by Douglas

Berthing mechanism final test report and program assessment

NASA Technical Reports Server (NTRS)

1988-01-01

The purpose is to document the testing performed on both hardware and software developed under the Space Station Berthing Mechanisms Program. Testing of the mechanism occurred at three locations. Several system components, e.g., actuators and computer systems, were functionally tested before assembly. A series of post assembly tests were performed. The post assembly tests, as well as the dynamic testing of the mechanism, are presented.

Quality data collection and management technology of aerospace complex product assembly process

NASA Astrophysics Data System (ADS)

Weng, Gang; Liu, Jianhua; He, Yongxi; Zhuang, Cunbo

2017-04-01

Aiming at solving problems of difficult management and poor traceability for discrete assembly process quality data, a data collection and management method is proposed which take the assembly process and BOM as the core. Data collection method base on workflow technology, data model base on BOM and quality traceability of assembly process is included in the method. Finally, assembly process quality data management system is developed and effective control and management of quality information for complex product assembly process is realized.

Development Specification for the Feedwater Supply Assembly (FSA), FSA-431 with Integrated Auxiliary Feedwater Supply Assembly (AFSA), FSA-531

NASA Technical Reports Server (NTRS)

Anchondo, Ian; Campbell, Colin

2017-01-01

The FSA with Integrated Aux FSA Specification establishes the requirements for design, performance, and testing of the FSA-431/FSA-531 assembly in compliance with CTSD-ADV-780, Development Specification for the Advanced EMU (AEMU) Portable Life Support System (PLSS). This section contains the technical design and performance requirements for the integrated assembly of the Feedwater Supply Assembly and Auxiliary Feedwater Supply Assembly for the Advanced EVA Development Portable Life Support Subsystem (PLSS).

Closeup view of the Solid Rocket Booster (SRB) Forward Skirt ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up view of the Solid Rocket Booster (SRB) Forward Skirt sitting on ground support equipment in the Solid Rocket Booster Assembly and Refurbishment Facility at Kennedy Space Center while being prepared for mating with the Frustum-Nose Cap Assembly and the Forward Rocket Motor Segment. The prominent feature in this view is the electrical, data, telemetry and safety systems terminal which connects to the Aft Skirt Assembly systems via the Systems Tunnel that runs the length of the Rocket Motor. - Space Transportation System, Solid Rocket Boosters, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Photon Upconversion and Molecular Solar Energy Storage by Maximizing the Potential of Molecular Self-Assembly.

PubMed

Kimizuka, Nobuo; Yanai, Nobuhiro; Morikawa, Masa-Aki

2016-11-29

The self-assembly of functional molecules into ordered molecular assemblies and the fulfillment of potentials unique to their nanotomesoscopic structures have been one of the central challenges in chemistry. This Feature Article provides an overview of recent progress in the field of molecular self-assembly with the focus on the triplet-triplet annihilation-based photon upconversion (TTA-UC) and supramolecular storage of photon energy. On the basis of the integration of molecular self-assembly and photon energy harvesting, triplet energy migration-based TTA-UC has been achieved in varied molecular systems. Interestingly, some molecular self-assemblies dispersed in solution or organogels revealed oxygen barrier properties, which allowed TTA-UC even under aerated conditions. The elements of molecular self-assembly were also introduced to the field of molecular solar thermal fuel, where reversible photoliquefaction of ionic crystals to ionic liquids was found to double the molecular storage capacity with the simultaneous pursuit of switching ionic conductivity. A future prospect in terms of innovating molecular self-assembly toward molecular systems chemistry is also discussed.

Predictor-corrector framework for the sequential assembly of optical systems based on wavefront sensing.

PubMed

Schindlbeck, Christopher; Pape, Christian; Reithmeier, Eduard

2018-04-16

Alignment of optical components is crucial for the assembly of optical systems to ensure their full functionality. In this paper we present a novel predictor-corrector framework for the sequential assembly of serial optical systems. Therein, we use a hybrid optical simulation model that comprises virtual and identified component positions. The hybrid model is constantly adapted throughout the assembly process with the help of nonlinear identification techniques and wavefront measurements. This enables prediction of the future wavefront at the detector plane and therefore allows for taking corrective measures accordingly during the assembly process if a user-defined tolerance on the wavefront error is violated. We present a novel notation for the so-called hybrid model and outline the work flow of the presented predictor-corrector framework. A beam expander is assembled as demonstrator for experimental verification of the framework. The optical setup consists of a laser, two bi-convex spherical lenses each mounted to a five degree-of-freedom stage to misalign and correct components, and a Shack-Hartmann sensor for wavefront measurements.

Inverse design of multicomponent assemblies

NASA Astrophysics Data System (ADS)

Piñeros, William D.; Lindquist, Beth A.; Jadrich, Ryan B.; Truskett, Thomas M.

2018-03-01

Inverse design can be a useful strategy for discovering interactions that drive particles to spontaneously self-assemble into a desired structure. Here, we extend an inverse design methodology—relative entropy optimization—to determine isotropic interactions that promote assembly of targeted multicomponent phases, and we apply this extension to design interactions for a variety of binary crystals ranging from compact triangular and square architectures to highly open structures with dodecagonal and octadecagonal motifs. We compare the resulting optimized (self- and cross) interactions for the binary assemblies to those obtained from optimization of analogous single-component systems. This comparison reveals that self-interactions act as a "primer" to position particles at approximately correct coordination shell distances, while cross interactions act as the "binder" that refines and locks the system into the desired configuration. For simpler binary targets, it is possible to successfully design self-assembling systems while restricting one of these interaction types to be a hard-core-like potential. However, optimization of both self- and cross interaction types appears necessary to design for assembly of more complex or open structures.

Internal combustion engine for natural gas compressor operation

DOEpatents

Hagen, Christopher L.; Babbitt, Guy; Turner, Christopher; Echter, Nick; Weyer-Geigel, Kristina

2016-04-19

This application concerns systems and methods for compressing natural gas with an internal combustion engine. In a representative embodiment, a system for compressing a gas comprises a reciprocating internal combustion engine including at least one piston-cylinder assembly comprising a piston configured to travel in a cylinder and to compress gas in the cylinder in multiple compression stages. The system can further comprise a first pressure tank in fluid communication with the piston-cylinder assembly to receive compressed gas from the piston-cylinder assembly until the first pressure tank reaches a predetermined pressure, and a second pressure tank in fluid communication with the piston-cylinder assembly and the first pressure tank. The second pressure tank can be configured to receive compressed gas from the piston-cylinder assembly until the second pressure tank reaches a predetermined pressure. When the first and second pressure tanks have reached the predetermined pressures, the first pressure tank can be configured to supply gas to the piston-cylinder assembly, and the piston can be configured to compress the gas supplied by the first pressure tank such that the compressed gas flows into the second pressure tank.

Apollo Guidance, Navigation, and Control (GNC) Hardware Overview

NASA Technical Reports Server (NTRS)

Interbartolo, Michael

2009-01-01

This viewgraph presentation reviews basic guidance, navigation and control (GNC) concepts, examines the Command and Service Module (CSM) and Lunar Module (LM) GNC organization and discusses the primary GNC and the CSM Stabilization and Control System (SCS), as well as other CSM-specific hardware. The LM Abort Guidance System (AGS), Control Electronics System (CES) and other LM-specific hardware are also addressed. Three subsystems exist on each vehicle: the computer subsystem (CSS), the inertial subsystem (ISS) and the optical subsystem (OSS). The CSS and ISS are almost identical between CSM and LM and each is designed to operate independently. CSM SCS hardware are highlighted, including translation control, rotation controls, gyro assemblies, a gyro display coupler and flight director attitude indicators. The LM AGS hardware are also highlighted and include the abort electronics assembly and the abort sensor assembly; while the LM CES hardware includes the attitude controller assembly, thrust/translation controller assemblies and the ascent engine arming assemble. Other common hardware including the Orbital Rate Display - Earth and Lunar (ORDEAL) and the Crewman Optical Alignment Sight (COAS), a docking aid, are also highlighted.

Emergency core cooling system

DOEpatents

Schenewerk, William E.; Glasgow, Lyle E.

1983-01-01

A liquid metal cooled fast breeder reactor provided with an emergency core cooling system includes a reactor vessel which contains a reactor core comprising an array of fuel assemblies and a plurality of blanket assemblies. The reactor core is immersed in a pool of liquid metal coolant. The reactor also includes a primary coolant system comprising a pump and conduits for circulating liquid metal coolant to the reactor core and through the fuel and blanket assemblies of the core. A converging-diverging venturi nozzle with an intermediate throat section is provided in between the assemblies and the pump. The intermediate throat section of the nozzle is provided with at least one opening which is in fluid communication with the pool of liquid sodium. In normal operation, coolant flows from the pump through the nozzle to the assemblies with very little fluid flowing through the opening in the throat. However, when the pump is not running, residual heat in the core causes fluid from the pool to flow through the opening in the throat of the nozzle and outwardly through the nozzle to the assemblies, thus providing a means of removing decay heat.

Optical diagnostics integrated with laser spark delivery system

DOEpatents

Yalin, Azer [Fort Collins, CO; Willson, Bryan [Fort Collins, CO; Defoort, Morgan [Fort Collins, CO; Joshi, Sachin [Fort Collins, CO; Reynolds, Adam [Fort Collins, CO

2008-09-02

A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

Fiber laser coupled optical spark delivery system

DOEpatents

Yalin, Azer [Fort Collins, CO; Willson, Bryan [Fort Collins, CO; Defoort, Morgan [Fort Collins, CO; Joshi, Sachin [Fort Collins, CO; Reynolds, Adam [Fort Collins, CO

2008-03-04

A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

Hyper-Assembly of Self-Assembled Glycoclusters Mediated by Specific Carbohydrate-Carbohydrate Interactions.

PubMed

Yan, Gengwei; Yamaguchi, Takumi; Suzuki, Tatsuya; Yanaka, Saeko; Sato, Sota; Fujita, Makoto; Kato, Koichi

2017-05-04

Hybridization of a self-assembled, spherical complex with oligosaccharides containing Lewis X, a functional trisaccharide displayed on various cell surfaces, yielded well-defined glycoclusters. The self-assembled glycoclusters exhibited homophilic hyper-assembly in aqueous solution in a Ca 2+ -dependent manner through specific carbohydrate-carbohydrate interactions, offering a structural scaffold for functional biomimetic systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Two-Step Self-Assembly of Liposome-Multidomain Peptide Nanofiber Hydrogel for Time-Controlled Release

PubMed Central

2015-01-01

Progress in self-assembly and supramolecular chemistry has been directed toward obtaining macromolecular assemblies with higher degrees of complexity, simulating the highly structured environment in natural systems. One approach to this type of complexity are multistep, multicomponent, self-assembling systems that allow approaches comparable to traditional multistep synthetic organic chemistry; however, only a few examples of this approach have appeared in the literature. Our previous work demonstrated nanofibrous mimics of the extracellular matrix. Here we demonstrate the ability to create a unique hydrogel, developed by stepwise self-assembly of multidomain peptide fibers and liposomes. The two-component system allows for controlled release of bioactive factors at multiple time points. The individual components of the self-assembled gel and the composite hydrogel were characterized by TEM, SEM, and rheometry, demonstrating that peptide nanofibers and lipid vesicles both retain their structural integrity in the composite gel. The rheological robustness of the hydrogel is shown to be largely unaffected by the presence of liposomes. Release studies from the composite gels loaded with different growth factors EGF, MCP-1, and PlGF-1 showed delay and prolongation of release by liposomes entrapped in the hydrogel compared to more rapid release from the hydrogel alone. This bimodal release system may have utility in systems where timed cascades of biological signals may be valuable, such as in tissue regeneration. PMID:25308335

Inverse Problem in Self-assembly

NASA Astrophysics Data System (ADS)

Tkachenko, Alexei

2012-02-01

By decorating colloids and nanoparticles with DNA, one can introduce highly selective key-lock interactions between them. This leads to a new class of systems and problems in soft condensed matter physics. In particular, this opens a possibility to solve inverse problem in self-assembly: how to build an arbitrary desired structure with the bottom-up approach? I will present a theoretical and computational analysis of the hierarchical strategy in attacking this problem. It involves self-assembly of particular building blocks (``octopus particles''), that in turn would assemble into the target structure. On a conceptual level, our approach combines elements of three different brands of programmable self assembly: DNA nanotechnology, nanoparticle-DNA assemblies and patchy colloids. I will discuss the general design principles, theoretical and practical limitations of this approach, and illustrate them with our simulation results. Our crucial result is that not only it is possible to design a system that has a given nanostructure as a ground state, but one can also program and optimize the kinetic pathway for its self-assembly.

Imaging enzyme-triggered self-assembly of small molecules inside live cells

PubMed Central

Gao, Yuan; Shi, Junfeng; Yuan, Dan; Xu, Bing

2012-01-01

Self-assembly of small molecules in water to form nanofibers, besides generating sophisticated biomaterials, promises a simple system inside cells for regulating cellular processes. But lack of a convenient approach for studying the self-assembly of small molecules inside cells hinders the development of such systems. Here we report a method to image enzyme-triggered self-assembly of small molecules inside live cells. After linking a fluorophore to a self-assembly motif to make a precursor, we confirmed by 31P NMR and rheology that enzyme-triggered conversion of the precursor to a hydrogelator results in the formation of a hydrogel via self-assembly. The imaging contrast conferred by the nanofibers of the hydrogelators allowed the evaluation of intracellular self-assembly; the dynamics, and the localization of the nanofibers of the hydrogelators in live cells. This approach explores supramolecular chemistry inside cells and may lead to new insights, processes, or materials at the interface of chemistry and biology. PMID:22929790

Morphological Transformation between Nanocoils and Nanoribbons via Defragmentation Structural Rearrangement or Fragmentation-recombination Mechanism

NASA Astrophysics Data System (ADS)

Zhang, Yibin; Zheng, Yingxuan; Xiong, Wei; Peng, Cheng; Zhang, Yifan; Duan, Ran; Che, Yanke; Zhao, Jincai

2016-06-01

Kinetic control over the assembly pathways towards novel metastable functional materials or far-from-equilibrium systems has been much less studied compared to the thermodynamic equilibrium self-assembly. Herein, we report the distinct morphological transformation between nanocoils and nanoribbons in the self-assembly of unsymmetric perylene diimide (PDI) molecules. We demonstrate that the morphological transformation of the kinetically trapped assemblies into the thermodynamically stable forms proceeds via two distinct mechanisms, i.e., a direct structural rearrangement (molecule 1 or 2) and a fragmentation-recombination mechanism (molecule 4), respectively. The subtle interplay of the steric hindrance of the bulky substituents and the flexibility of the linker structure between the bulky moiety and the perylene core was demonstrated to enable the effective modulation of the energetic landscape of the assemblies and thus modulation of the assembly pathways. Herein, our work presents a new approach to control the self-assembly pathways and thereby can be used to achieve novel far-from-equilibrium systems.

Inventorying national forest resources...for planning-programing-budgeting system

Treesearch

Miles R. Hill; Elliot L. Amidon

1968-01-01

New systems for analyzing resource management problems, such as Planning-Programing-Budgeting, will require automated procedures to collect and assemble resource inventory data. A computer - oriented system called Map Information Assembly and Display System developed for this purpose was tested on a National Forest in California. It provided information on eight forest...

An exactly solvable model of hierarchical self-assembly

NASA Astrophysics Data System (ADS)

Dudowicz, Jacek; Douglas, Jack F.; Freed, Karl F.

2009-06-01

Many living and nonliving structures in the natural world form by hierarchical organization, but physical theories that describe this type of organization are scarce. To address this problem, a model of equilibrium self-assembly is formulated in which dynamically associating species organize into hierarchical structures that preserve their shape at each stage of assembly. In particular, we consider symmetric m-gons that associate at their vertices into Sierpinski gasket structures involving the hierarchical association of triangles, squares, hexagons, etc., at their corner vertices, thereby leading to fractal structures after many generations of assembly. This rather idealized model of hierarchical assembly yields an infinite sequence of self-assembly transitions as the morphology progressively organizes to higher levels of the hierarchy, and these structures coexists at dynamic equilibrium, as found in real hierarchically self-assembling systems such as amyloid fiber forming proteins. Moreover, the transition sharpness progressively grows with increasing m, corresponding to larger and larger loops in the assembled structures. Calculations are provided for several basic thermodynamic properties (including the order parameters for assembly for each stage of the hierarchy, average mass of clusters, specific heat, transition sharpness, etc.) that are required for characterizing the interaction parameters governing this type of self-assembly and for elucidating other basic qualitative aspects of these systems. Our idealized model of hierarchical assembly gives many insights into this ubiquitous type of self-organization process.

CSM docked DAP/orbital assembly bending interaction-axial case

NASA Technical Reports Server (NTRS)

Turnbull, J. F.; Jones, J. E.

1972-01-01

A digital autopilot which can provide attitude control for the entire Skylab orbital assembly using the service module reaction control jets is described. An important consideration is the potential interaction of the control system with the bending modes of the orbital assembly. Two aspects of this potential interaction were considered. The first was the possibility that bending induced rotations feeding back through the attitude sensor into the control system could produce an instability or self-sustained oscillation. The second was whether the jet activity commanded by the control system could produce excessive loads at any of the critical load points of the orbital assembly. Both aspects were studied by using analytic techniques and by running simulations on the all-digital simulator.

iLIDS Simulations and Videos for Docking TIM

NASA Technical Reports Server (NTRS)

Lewis, James L.

2010-01-01

The video shows various aspects of the International Low Impact Docking System, including team members, some production, configuration, mated androgynous iLIDS, SCS Lockdown system, thermal analysis, electrical engineering aspects, the iLIDS control box and emulator, radiation testing at BNL, component environmental testing, component vibration testing, 3G processor board delivery system, GTA vibe test, EMA testbed, hook and hook disassembly, flex shaftdrive assembly, GSE cradle MISSE-6 Columbus, MISSE 6 and 7 seal experiments, actuated full scale seal test rig, LIDS on Hubble, dynamics test prep, EDU 54 mass emulation and SCS, load ring characterization, 6DOF proof test, SCS at 6DOF, machining EEMS and inner ring assembly, APAS assembly, inner ring fitting, rotation stand assembly, EEMS mating, and EEMS proof of concept demonstration.

Mineral Surface-Templated Self-Assembling Systems: Case Studies from Nanoscience and Surface Science towards Origins of Life Research.

PubMed

Gillams, Richard J; Jia, Tony Z

2018-05-08

An increasing body of evidence relates the wide range of benefits mineral surfaces offer for the development of early living systems, including adsorption of small molecules from the aqueous phase, formation of monomeric subunits and their subsequent polymerization, and supramolecular assembly of biopolymers and other biomolecules. Each of these processes was likely a necessary stage in the emergence of life on Earth. Here, we compile evidence that templating and enhancement of prebiotically-relevant self-assembling systems by mineral surfaces offers a route to increased structural, functional, and/or chemical complexity. This increase in complexity could have been achieved by early living systems before the advent of evolvable systems and would not have required the generally energetically unfavorable formation of covalent bonds such as phosphodiester or peptide bonds. In this review we will focus on various case studies of prebiotically-relevant mineral-templated self-assembling systems, including supramolecular assemblies of peptides and nucleic acids, from nanoscience and surface science. These fields contain valuable information that is not yet fully being utilized by the origins of life and astrobiology research communities. Some of the self-assemblies that we present can promote the formation of new mineral surfaces, similar to biomineralization, which can then catalyze more essential prebiotic reactions; this could have resulted in a symbiotic feedback loop by which geology and primitive pre-living systems were closely linked to one another even before life’s origin. We hope that the ideas presented herein will seed some interesting discussions and new collaborations between nanoscience/surface science researchers and origins of life/astrobiology researchers.

Direct assembling methodologies for high-throughput bioscreening

PubMed Central

Rodríguez-Dévora, Jorge I.; Shi, Zhi-dong; Xu, Tao

2012-01-01

Over the last few decades, high-throughput (HT) bioscreening, a technique that allows rapid screening of biochemical compound libraries against biological targets, has been widely used in drug discovery, stem cell research, development of new biomaterials, and genomics research. To achieve these ambitions, scaffold-free (or direct) assembly of biological entities of interest has become critical. Appropriate assembling methodologies are required to build an efficient HT bioscreening platform. The development of contact and non-contact assembling systems as a practical solution has been driven by a variety of essential attributes of the bioscreening system, such as miniaturization, high throughput, and high precision. The present article reviews recent progress on these assembling technologies utilized for the construction of HT bioscreening platforms. PMID:22021162

EVA manipulation and assembly of space structure columns

NASA Technical Reports Server (NTRS)

Loughead, T. E.; Pruett, E. C.

1980-01-01

Assembly techniques and hardware configurations used in assembly of the basic tetrahedral cell by A7LB pressure-suited subjects in a neutral bouyancy simulator were studied. Eleven subjects participated in assembly procedures which investigated two types of structural members and two configurations of attachment hardware. The assembly was accomplished through extra-vehicular activity (EVA) only, EVA with simulated manned maneuvering unit (MMU), and EVA with simulated MMU and simulated remote manipulator system (RMS). Assembly times as low as 10.20 minutes per tetrahedron were achieved. Task element data, as well as assembly procedures, are included.

Self-assembled lipid bilayer materials

DOEpatents

Sasaki, Darryl Y.; Waggoner, Tina A.; Last, Julie A.

2005-11-08

The present invention is a self-assembling material comprised of stacks of lipid bilayers formed in a columnar structure, where the assembly process is mediated and regulated by chemical recognition events. The material, through the chemical recognition interactions, has a self-regulating system that corrects the radial size of the assembly creating a uniform diameter throughout most of the structure. The materials form and are stable in aqueous solution. These materials are useful as structural elements for the architecture of materials and components in nanotechnology, efficient light harvesting systems for optical sensing, chemical processing centers, and drug delivery vehicles.

X-ray source assembly having enhanced output stability, and fluid stream analysis applications thereof

DOEpatents

Radley, Ian [Glenmont, NY; Bievenue, Thomas J [Delmar, NY; Burdett, John H [Charlton, NY; Gallagher, Brian W [Guilderland, NY; Shakshober, Stuart M [Hudson, NY; Chen, Zewu [Schenectady, NY; Moore, Michael D [Alplaus, NY

2008-06-08

An x-ray source assembly and method of operation are provided having enhanced output stability. The assembly includes an anode having a source spot upon which electrons impinge and a control system for controlling position of the anode source spot relative to an output structure. The control system can maintain the anode source spot location relative to the output structure notwithstanding a change in one or more operating conditions of the x-ray source assembly. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.

Tendon Driven Finger Actuation System

NASA Technical Reports Server (NTRS)

Ihrke, Chris A. (Inventor); Reich, David M. (Inventor); Bridgwater, Lyndon (Inventor); Linn, Douglas Martin (Inventor); Askew, Scott R. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Hargrave, Brian (Inventor); Valvo, Michael C. (Inventor); Abdallah, Muhammad E. (Inventor);

Floating modular drug delivery systems with buoyancy independent of release mechanisms to sustain amoxicillin and clarithromycin intra-gastric concentrations.

PubMed

Rossi, Alessandra; Conti, Chiara; Colombo, Gaia; Castrati, Luca; Scarpignato, Carmelo; Barata, Pedro; Sandri, Giuseppina; Caramella, Carla; Bettini, Ruggero; Buttini, Francesca; Colombo, Paolo

2016-01-01

Release modules of amoxicillin and clarithromycin combined in a single dosage form designed to float in the gastric content and to sustain the intra-gastric concentrations of these two antibiotics used for the eradication of Helicobacter pylori have been studied. The modules having a disc shape with curved bases were formulated as hydrophilic matrices. Two modules of clarithromycin were assembled by sticking the concave base of one module to the concave base of the other, creating an internal void chamber. The final dosage form was a floating assembly of three modules of clarithromycin and two of amoxicillin in which the drug release mechanism did not interfere with the floatation mechanism. The assembled system showed immediate in vitro floatation at pH 1.2, lasting 5 h. The in vitro antibiotics release profiles from individual modules and assembled systems exhibited linear release rate during buoyancy for at least 8 h. The predicted antibiotic concentrations in the stomach maintained for long time levels significantly higher than the respective minimum inhibitory concentrations (MIC). In addition, an in vivo absorption study performed on beagle dogs confirmed the slow release of clarithromycin and amoxicillin from the assembled system during the assembly's permanence in the stomach for at least 4 h.

Optimized Assembly of a Multifunctional RNA-Protein Nanostructure in a Cell-Free Gene Expression System.

PubMed

Schwarz-Schilling, Matthaeus; Dupin, Aurore; Chizzolini, Fabio; Krishnan, Swati; Mansy, Sheref S; Simmel, Friedrich C

2018-04-11

Molecular complexes composed of RNA molecules and proteins are promising multifunctional nanostructures for a wide variety of applications in biological cells or in artificial cellular systems. In this study, we systematically address some of the challenges associated with the expression and assembly of such hybrid structures using cell-free gene expression systems. As a model structure, we investigated a pRNA-derived RNA scaffold functionalized with four distinct aptamers, three of which bind to proteins, streptavidin and two fluorescent proteins, while one binds the small molecule dye malachite green (MG). Using MG fluorescence and Förster resonance energy transfer (FRET) between the RNA-scaffolded proteins, we assess critical assembly parameters such as chemical stability, binding efficiency, and also resource sharing effects within the reaction compartment. We then optimize simultaneous expression and coassembly of the RNA-protein nanostructure within a single-compartment cell-free gene expression system. We demonstrate expression and assembly of the multicomponent nanostructures inside of emulsion droplets and their aptamer-mediated localization onto streptavidin-coated substrates, plus the successful assembly of the hybrid structures inside of bacterial cells.

DNAzyme-Based Logic Gate-Mediated DNA Self-Assembly.

PubMed

Zhang, Cheng; Yang, Jing; Jiang, Shuoxing; Liu, Yan; Yan, Hao

2016-01-13

Controlling DNA self-assembly processes using rationally designed logic gates is a major goal of DNA-based nanotechnology and programming. Such controls could facilitate the hierarchical engineering of complex nanopatterns responding to various molecular triggers or inputs. Here, we demonstrate the use of a series of DNAzyme-based logic gates to control DNA tile self-assembly onto a prescribed DNA origami frame. Logic systems such as "YES," "OR," "AND," and "logic switch" are implemented based on DNAzyme-mediated tile recognition with the DNA origami frame. DNAzyme is designed to play two roles: (1) as an intermediate messenger to motivate downstream reactions and (2) as a final trigger to report fluorescent signals, enabling information relay between the DNA origami-framed tile assembly and fluorescent signaling. The results of this study demonstrate the plausibility of DNAzyme-mediated hierarchical self-assembly and provide new tools for generating dynamic and responsive self-assembly systems.

Liquid-liquid interfacial nanoparticle assemblies

DOEpatents

Emrick, Todd S [South Deerfield, MA; Russell, Thomas P [Amherst, MA; Dinsmore, Anthony [Amherst, MA; Skaff, Habib [Amherst, MA; Lin, Yao [Amherst, MA

2008-12-30

Self-assembly of nanoparticles at the interface between two fluids, and methods to control such self-assembly process, e.g., the surface density of particles assembling at the interface; to utilize the assembled nanoparticles and their ligands in fabrication of capsules, where the elastic properties of the capsules can be varied from soft to tough; to develop capsules with well-defined porosities for ultimate use as delivery systems; and to develop chemistries whereby multiple ligands or ligands with multiple functionalities can be attached to the nanoparticles to promote the interfacial segregation and assembly of the nanoparticles. Certain embodiments use cadmium selenide (CdSe) nanoparticles, since the photoluminescence of the particles provides a convenient means by which the spatial location and organization of the particles can be probed. However, the systems and methodologies presented here are general and can, with suitable modification of the chemistries, be adapted to any type of nanoparticle.

Spent nuclear fuel system dynamic stability under normal conditions of transportation

DOE PAGES

Jiang, Hao; Wang, Jy-An John

2016-10-14

In a horizontal layout of a spent nuclear fuel (SNF) assembly under normal conditions of transportation (NCT), the fuel assembly’s skeleton formed by guide tubes and spacer grids is the primary load bearing structure for carrying and transferring the vibration loads within an SNF assembly. Therefore, the integrity of guide tubes and spacer grids will dictate the vibration amplitude/intensity of the fuel assembly during transport, and must be considered when designing multipurpose purpose canister (MPC) for safe SNF transport. This paper investigates the SNF assembly deformation dynamics during normal vibration mode, as well as the transient shock mode inside themore » cask during NCT. In conclusion, dynamic analyses were performed in the frequency domain to study frequency characteristic of the fuel assembly system and in the time domain to simulate the transient dynamic response of the fuel assembly.« less

In vitro reconstitution of chaperone-mediated human RISC assembly.

PubMed

Naruse, Ken; Matsuura-Suzuki, Eriko; Watanabe, Mariko; Iwasaki, Shintaro; Tomari, Yukihide

2018-01-01

To silence target mRNAs, small RNAs and Argonaute (Ago) proteins need to be assembled into RNA-induced silencing complexes (RISCs). Although the assembly of Drosophila melanogaster RISC was recently reconstituted by Ago2, the Dicer-2/R2D2 heterodimer, and five chaperone proteins, the absence of a reconstitution system for mammalian RISC assembly has posed analytical challenges. Here we describe reconstitution of human RISC assembly using Ago2 and five recombinant chaperone proteins: Hsp90β, Hsc70, Hop, Dnaja2, and p23. Our data show that ATP hydrolysis by both Hsp90β and Hsc70 is required for RISC assembly of small RNA duplexes but not for that of single-stranded RNAs. The reconstitution system lays the groundwork for further studies of small RNA-mediated gene silencing in mammals. © 2018 Naruse et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Spent nuclear fuel system dynamic stability under normal conditions of transportation

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

Jiang, Hao; Wang, Jy-An John

In a horizontal layout of a spent nuclear fuel (SNF) assembly under normal conditions of transportation (NCT), the fuel assembly’s skeleton formed by guide tubes and spacer grids is the primary load bearing structure for carrying and transferring the vibration loads within an SNF assembly. Therefore, the integrity of guide tubes and spacer grids will dictate the vibration amplitude/intensity of the fuel assembly during transport, and must be considered when designing multipurpose purpose canister (MPC) for safe SNF transport. This paper investigates the SNF assembly deformation dynamics during normal vibration mode, as well as the transient shock mode inside themore » cask during NCT. In conclusion, dynamic analyses were performed in the frequency domain to study frequency characteristic of the fuel assembly system and in the time domain to simulate the transient dynamic response of the fuel assembly.« less

Single Day Construction of Multigene Circuits with 3G Assembly.

PubMed

Halleran, Andrew D; Swaminathan, Anandh; Murray, Richard M

2018-05-18

The ability to rapidly design, build, and test prototypes is of key importance to every engineering discipline. DNA assembly often serves as a rate limiting step of the prototyping cycle for synthetic biology. Recently developed DNA assembly methods such as isothermal assembly and type IIS restriction enzyme systems take different approaches to accelerate DNA construction. We introduce a hybrid method, Golden Gate-Gibson (3G), that takes advantage of modular part libraries introduced by type IIS restriction enzyme systems and isothermal assembly's ability to build large DNA constructs in single pot reactions. Our method is highly efficient and rapid, facilitating construction of entire multigene circuits in a single day. Additionally, 3G allows generation of variant libraries enabling efficient screening of different possible circuit constructions. We characterize the efficiency and accuracy of 3G assembly for various construct sizes, and demonstrate 3G by characterizing variants of an inducible cell-lysis circuit.

SIMBA: a web tool for managing bacterial genome assembly generated by Ion PGM sequencing technology.

PubMed

Mariano, Diego C B; Pereira, Felipe L; Aguiar, Edgar L; Oliveira, Letícia C; Benevides, Leandro; Guimarães, Luís C; Folador, Edson L; Sousa, Thiago J; Ghosh, Preetam; Barh, Debmalya; Figueiredo, Henrique C P; Silva, Artur; Ramos, Rommel T J; Azevedo, Vasco A C

2016-12-15

The evolution of Next-Generation Sequencing (NGS) has considerably reduced the cost per sequenced-base, allowing a significant rise of sequencing projects, mainly in prokaryotes. However, the range of available NGS platforms requires different strategies and software to correctly assemble genomes. Different strategies are necessary to properly complete an assembly project, in addition to the installation or modification of various software. This requires users to have significant expertise in these software and command line scripting experience on Unix platforms, besides possessing the basic expertise on methodologies and techniques for genome assembly. These difficulties often delay the complete genome assembly projects. In order to overcome this, we developed SIMBA (SImple Manager for Bacterial Assemblies), a freely available web tool that integrates several component tools for assembling and finishing bacterial genomes. SIMBA provides a friendly and intuitive user interface so bioinformaticians, even with low computational expertise, can work under a centralized administrative control system of assemblies managed by the assembly center head. SIMBA guides the users to execute assembly process through simple and interactive pages. SIMBA workflow was divided in three modules: (i) projects: allows a general vision of genome sequencing projects, in addition to data quality analysis and data format conversions; (ii) assemblies: allows de novo assemblies with the software Mira, Minia, Newbler and SPAdes, also assembly quality validations using QUAST software; and (iii) curation: presents methods to finishing assemblies through tools for scaffolding contigs and close gaps. We also presented a case study that validated the efficacy of SIMBA to manage bacterial assemblies projects sequenced using Ion Torrent PGM. Besides to be a web tool for genome assembly, SIMBA is a complete genome assemblies project management system, which can be useful for managing of several projects in laboratories. SIMBA source code is available to download and install in local webservers at http://ufmg-simba.sourceforge.net .

PAVE: program for assembling and viewing ESTs.

PubMed

Soderlund, Carol; Johnson, Eric; Bomhoff, Matthew; Descour, Anne

2009-08-26

New sequencing technologies are rapidly emerging. Many laboratories are simultaneously working with the traditional Sanger ESTs and experimenting with ESTs generated by the 454 Life Science sequencers. Though Sanger ESTs have been used to generate contigs for many years, no program takes full advantage of the 5' and 3' mate-pair information, hence, many tentative transcripts are assembled into two separate contigs. The new 454 technology has the benefit of high-throughput expression profiling, but introduces time and space problems for assembling large contigs. The PAVE (Program for Assembling and Viewing ESTs) assembler takes advantage of the 5' and 3' mate-pair information by requiring that the mate-pairs be assembled into the same contig and joined by n's if the two sub-contigs do not overlap. It handles the depth of 454 data sets by "burying" similar ESTs during assembly, which retains the expression level information while circumventing time and space problems. PAVE uses MegaBLAST for the clustering step and CAP3 for assembly, however it assembles incrementally to enforce the mate-pair constraint, bury ESTs, and reduce incorrect joins and splits. The PAVE data management system uses a MySQL database to store multiple libraries of ESTs along with their metadata; the management system allows multiple assemblies with variations on libraries and parameters. Analysis routines provide standard annotation for the contigs including a measure of differentially expressed genes across the libraries. A Java viewer program is provided for display and analysis of the results. Our results clearly show the benefit of using the PAVE assembler to explicitly use mate-pair information and bury ESTs for large contigs. The PAVE assembler provides a software package for assembling Sanger and/or 454 ESTs. The assembly software, data management software, Java viewer and user's guide are freely available.

Process for reducing series resistance of solar-cell metal-contact systems with a soldering-flux etchant

DOEpatents

Coyle, R.T.; Barrett, J.M.

1982-05-04

Disclosed is a process for substantially reducing the series resistance of a solar cell having a thick film metal contact assembly thereon while simultaneously removing oxide coatings from the surface of the assembly prior to applying solder therewith. The process includes applying a flux to the contact assembly and heating the cell for a period of time sufficient to substantially remove the series resistance associated with the assembly by etching the assembly with the flux while simultaneously removing metal oxides from said surface of said assembly.

Process for reducing series resistance of solar cell metal contact systems with a soldering flux etchant

DOEpatents

Coyle, R. T.; Barrett, Joy M.

1984-01-01

Disclosed is a process for substantially reducing the series resistance of a solar cell having a thick film metal contact assembly thereon while simultaneously removing oxide coatings from the surface of the assembly prior to applying solder therewith. The process includes applying a flux to the contact assembly and heating the cell for a period of time sufficient to substantially remove the series resistance associated with the assembly by etching the assembly with the flux while simultaneously removing metal oxides from said surface of said assembly.

Dynamic pathways for viral capsid assembly

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

Hagan, Michael F.; Chandler, David

2006-02-09

We develop a class of models with which we simulate the assembly of particles into T1 capsid-like objects using Newtonian dynamics. By simulating assembly for many different values of system parameters, we vary the forces that drive assembly. For some ranges of parameters, assembly is facile, while for others, assembly is dynamically frustrated by kinetic traps corresponding to malformed or incompletely formed capsids. Our simulations sample many independent trajectories at various capsomer concentrations, allowing for statistically meaningful conclusions. Depending on subunit (i.e., capsomer) geometries, successful assembly proceeds by several mechanisms involving binding of intermediates of various sizes. We discuss themore » relationship between these mechanisms and experimental evaluations of capsid assembly processes.« less

78 FR 54561 - Airworthiness Directives; Piper Aircraft, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-05

... for Lycoming and Piper Exhaust System Parts, for the entry ``tail pipe assembly, top'' in the third...-31-350, tail pipe assembly, top. This document corrects that error. In all other respects, the... exhaust system, expanding the inspection scope to include the entirety of each airplane exhaust system...

Outboard Repair.

ERIC Educational Resources Information Center

Hardway, Jack

This consortium-developed instructor's manual for small engine repair (with focus on outboard motors) consists of the following nine instructional units: electrical remote control assembly, mechanical remote control assembly, tilt assemblies, exhaust housing, propeller and trim tabs, cooling system, mechanical gearcase, electrical gearcase, and…

76 FR 12825 - List of Approved Spent Fuel Storage Casks: NUHOMS® HD System Revision 1; Confirmation of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-09

... definitions for Damaged Fuel Assembly and Transfer Operations; add definitions for Fuel Class and Reconstituted Fuel Assembly; add Combustion Engineering 16x16 class fuel assemblies as authorized contents...

Crystal Structure of the Minor Pilin CofB, the Initiator of CFA/III Pilus Assembly in Enterotoxigenic Escherichia coli*

PubMed Central

Kolappan, Subramania; Ng, Dixon; Yang, Guixiang; Harn, Tony; Craig, Lisa

2015-01-01

Type IV pili are extracellular polymers of the major pilin subunit. These subunits are held together in the pilus filament by hydrophobic interactions among their N-terminal α-helices, which also anchor the pilin subunits in the inner membrane prior to pilus assembly. Type IV pilus assembly involves a conserved group of proteins that span the envelope of Gram-negative bacteria. Among these is a set of minor pilins, so named because they share their hydrophobic N-terminal polymerization/membrane anchor segment with the major pilins but are much less abundant. Minor pilins influence pilus assembly and retraction, but their precise functions are not well defined. The Type IV pilus systems of enterotoxigenic Escherichia coli and Vibrio cholerae are among the simplest of Type IV pilus systems and possess only a single minor pilin. Here we show that the enterotoxigenic E. coli minor pilins CofB and LngB are required for assembly of their respective Type IV pili, CFA/III and Longus. Low levels of the minor pilins are optimal for pilus assembly, and CofB can be detected in the pilus fraction. We solved the 2.0 Å crystal structure of N-terminally truncated CofB, revealing a pilin-like protein with an extended C-terminal region composed of two discrete domains connected by flexible linkers. The C-terminal region is required for CofB to initiate pilus assembly. We propose a model for CofB-initiated pilus assembly with implications for understanding filament growth in more complex Type IV pilus systems as well as the related Type II secretion system. PMID:26324721

Crystal Structure of the Minor Pilin CofB, the Initiator of CFA/III Pilus Assembly in Enterotoxigenic Escherichia coli.

PubMed

Kolappan, Subramania; Ng, Dixon; Yang, Guixiang; Harn, Tony; Craig, Lisa

2015-10-23

Type IV pili are extracellular polymers of the major pilin subunit. These subunits are held together in the pilus filament by hydrophobic interactions among their N-terminal α-helices, which also anchor the pilin subunits in the inner membrane prior to pilus assembly. Type IV pilus assembly involves a conserved group of proteins that span the envelope of Gram-negative bacteria. Among these is a set of minor pilins, so named because they share their hydrophobic N-terminal polymerization/membrane anchor segment with the major pilins but are much less abundant. Minor pilins influence pilus assembly and retraction, but their precise functions are not well defined. The Type IV pilus systems of enterotoxigenic Escherichia coli and Vibrio cholerae are among the simplest of Type IV pilus systems and possess only a single minor pilin. Here we show that the enterotoxigenic E. coli minor pilins CofB and LngB are required for assembly of their respective Type IV pili, CFA/III and Longus. Low levels of the minor pilins are optimal for pilus assembly, and CofB can be detected in the pilus fraction. We solved the 2.0 Å crystal structure of N-terminally truncated CofB, revealing a pilin-like protein with an extended C-terminal region composed of two discrete domains connected by flexible linkers. The C-terminal region is required for CofB to initiate pilus assembly. We propose a model for CofB-initiated pilus assembly with implications for understanding filament growth in more complex Type IV pilus systems as well as the related Type II secretion system. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Thermodynamic performance testing of the orbiter flash evaporator system

NASA Technical Reports Server (NTRS)

Jaax, J. R.; Melgares, M. A.; Frahm, J. P.

1980-01-01

System level testing of the space shuttle orbiter's development flash evaporator system (FES) was performed in a thermal vacuum chamber capable of simulating ambient ascent, orbital, and entry temperature and pressure profiles. The test article included the evaporator assembly, high load and topping exhaust duct and nozzle assemblies, and feedwater supply assembly. Steady state and transient heat load, water pressure/temperature and ambient pressure/temperature profiles were imposed by especially designed supporting test hardware. Testing in 1978 verified evaporator and duct heater thermal design, determined FES performance boundaries, and assessed topping evaporator plume characteristics. Testing in 1979 combined the FES with the other systems in the orbiter active thermal control subsystem (ATCS). The FES met or exceeded all nominal and contingency performance requirements during operation with the integrated ATCS. During both tests stability problems were encountered during steady state operations which resulted in subsequent design changes to the water spray nozzle and valve plate assemblies.

Power system interface and umbilical system study

NASA Technical Reports Server (NTRS)

1980-01-01

System requirements and basic design criteria were defined for berthing or docking a payload to the 25 kW power module which will provide electrical power and attitude control, cooling, data transfer, and communication services to free-flying and Orbiter sortie payloads. The selected umbilical system concept consists of four assemblies and command and display equipment to be installed at the Orbiter payload specialist station: (1) a movable platen assembly which is attached to the power system with EVA operable devices; (2) a slave platen assembly which is attached to the payload with EVA operable devices; (3) a fixed secondary platen permanently installed in the power system; and (4) a fixed secondary platen permanently installed on the payload. Operating modes and sequences are described.

Support for solar energy collectors

DOEpatents

Cole, Corey; Ardell-Smith, Zachary; Ciasulli, John; Jensen, Soren

2016-11-01

A solar energy collection system can include support devices configured to accommodate misalignment of components during assembly. For example, the system can include piles fixed to the earth and an adjustable bearing assembly at the upper end of the pile. The adjustable bearing assembly can include at least one of a vertical adjustment device, a lateral adjustment device and an angular adjustment device. The solar energy collection system can also include a plurality of solar energy collection device pre-wired together and mounted to a support member so as to form modular units. The system can also include enhanced supports for wire trays extending between rows of solar energy collection devices.

System and method for mass production of graphene platelets in arc plasma

DOEpatents

Keidar, Michael; Shashurin, Alexey

2017-12-12

A system and method for producing graphene includes a discharge assembly and a substrate assembly. The discharge assembly includes a cathode and an anode, which in one embodiment are offset from each other. The anode produces a flux stream that is deposited onto a substrate. A collection device removes the deposited material from the rotating substrate. The flux stream can be a carbon vapor, with the deposited flux being graphene.

Improving Robotic Assembly of Planar High Energy Density Targets

NASA Astrophysics Data System (ADS)

Dudt, D.; Carlson, L.; Alexander, N.; Boehm, K.

2016-10-01

Increased quantities of planar assemblies for high energy density targets are needed with higher shot rates being implemented at facilities such as the National Ignition Facility and the Matter in Extreme Conditions station of the Linac Coherent Light Source. To meet this growing demand, robotics are used to reduce assembly time. This project studies how machine vision and force feedback systems can be used to improve the quantity and quality of planar target assemblies. Vision-guided robotics can identify and locate parts, reducing laborious manual loading of parts into precision pallets and associated teaching of locations. On-board automated inspection can measure part pickup offsets to correct part drop-off placement into target assemblies. Force feedback systems can detect pickup locations and apply consistent force to produce more uniform glue bond thickness, thus improving the performance of the targets. System designs and performance evaluations will be presented. Work supported in part by the US DOE under the Science Undergraduate Laboratory Internships Program (SULI) and ICF Target Fabrication DE-NA0001808.

Complex collective dynamics of active torque-driven colloids at interfaces

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

Snezhko, Alexey

Modern self-assembly techniques aiming to produce complex structural order or functional diversity often rely on non-equilibrium conditions in the system. Light, electric, or magnetic fields are predominantly used to modify interaction profiles of colloidal particles during self-assembly or induce complex out-of-equilibrium dynamic ordering. The energy injection rate, properties of the environment are important control parameters that influence the outcome of active (dynamic) self-assembly. The current review is focused on a case of collective dynamics and self-assembly of particles with externally driven torques coupled to a liquid or solid interface. The complexity of interactions in such systems is further enriched bymore » strong hydrodynamic coupling between particles. Unconventionally ordered dynamic self-assembled patterns, spontaneous symmetry breaking phenomena, self-propulsion, and collective transport have been reported in torque-driven colloids. Some of the features of the complex collective behavior and dynamic pattern formation in those active systems have been successfully captured in simulations.« less

Artificial muscle-like function from hierarchical supramolecular assembly of photoresponsive molecular motors

NASA Astrophysics Data System (ADS)

Chen, Jiawen; Leung, Franco King-Chi; Stuart, Marc C. A.; Kajitani, Takashi; Fukushima, Takanori; van der Giessen, Erik; Feringa, Ben L.

2018-02-01

A striking feature of living systems is their ability to produce motility by amplification of collective molecular motion from the nanoscale up to macroscopic dimensions. Some of nature's protein motors, such as myosin in muscle tissue, consist of a hierarchical supramolecular assembly of very large proteins, in which mechanical stress induces a coordinated movement. However, artificial molecular muscles have often relied on covalent polymer-based actuators. Here, we describe the macroscopic contractile muscle-like motion of a supramolecular system (comprising 95% water) formed by the hierarchical self-assembly of a photoresponsive amphiphilic molecular motor. The molecular motor first assembles into nanofibres, which further assemble into aligned bundles that make up centimetre-long strings. Irradiation induces rotary motion of the molecular motors, and propagation and accumulation of this motion lead to contraction of the fibres towards the light source. This system supports large-amplitude motion, fast response, precise control over shape, as well as weight-lifting experiments in water and air.

Androgynous, Reconfigurable Closed Loop Feedback Controlled Low Impact Docking System With Load Sensing Electromagnetic Capture Ring

NASA Technical Reports Server (NTRS)

Lewis, James L. (Inventor); Carroll, Monty B. (Inventor); Morales, Ray H. (Inventor); Le, Thang D. (Inventor)

2002-01-01

The present invention relates to a fully androgynous, reconfigurable closed loop feedback controlled low impact docking system with load sensing electromagnetic capture ring. The docking system of the present invention preferably comprises two Docking- assemblies, each docking assembly comprising a load sensing ring having an outer face, one of more electromagnets, one or more load cells coupled to said load sensing ring. The docking assembly further comprises a plurality of actuator arms coupled to said load sensing ring and capable of dynamically adjusting the orientation of said load sensing ring and a reconfigurable closed loop control system capable of analyzing signals originating from said plurality of load cells and of outputting real time control for each of the actuators. The docking assembly of the present invention incorporates an active load sensing system to automatically dynamically adjust the load sensing ring during capture instead of requiring significant force to push and realign the ring.

The microviridae: Diversity, assembly, and experimental evolution.

PubMed

Doore, Sarah M; Fane, Bentley A

2016-04-01

The Microviridae, comprised of ssDNA, icosahedral bacteriophages, are a model system for studying morphogenesis and the evolution of assembly. Historically limited to the φX174-like viruses, recent results demonstrate that this richly diverse family is broadly divided into two groups. The defining feature appears to be whether one or two scaffolding proteins are required for assembly. The single-scaffolding systems contain an internal scaffolding protein, similar to many dsDNA viruses, and have a more complex coat protein fold. The two-scaffolding protein systems (φX174-like) encode an internal and external species, as well as an additional structural protein: a spike on the icosahedral vertices. Here, we discuss recent in silico and in vivo evolutionary analyses conducted with chimeric viruses and/or chimeric proteins. The results suggest 1) how double scaffolding systems can evolve into single and triple scaffolding systems; and 2) how assembly is the critical factor governing adaptation and the maintenance of species boundaries. Copyright © 2016 Elsevier Inc. All rights reserved.

Innovative applications of artificial intelligence

NASA Astrophysics Data System (ADS)

Schorr, Herbert; Rappaport, Alain

Papers concerning applications of artificial intelligence are presented, covering applications in aerospace technology, banking and finance, biotechnology, emergency services, law, media planning, music, the military, operations management, personnel management, retail packaging, and manufacturing assembly and design. Specific topics include Space Shuttle telemetry monitoring, an intelligent training system for Space Shuttle flight controllers, an expert system for the diagnostics of manufacturing equipment, a logistics management system, a cooling systems design assistant, and a knowledge-based integrated circuit design critic. Additional topics include a hydraulic circuit design assistant, the use of a connector assembly specification expert system to harness detailed assembly process knowledge, a mixed initiative approach to airlift planning, naval battle management decision aids, an inventory simulation tool, a peptide synthesis expert system, and a system for planning the discharging and loading of container ships.

Automated and model-based assembly of an anamorphic telescope

NASA Astrophysics Data System (ADS)

Holters, Martin; Dirks, Sebastian; Stollenwerk, Jochen; Loosen, Peter

2018-02-01

Since the first usage of optical glasses there has been an increasing demand for optical systems which are highly customized for a wide field of applications. To meet the challenge of the production of so many unique systems, the development of new techniques and approaches has risen in importance. However, the assembly of precision optical systems with lot sizes of one up to a few tens of systems is still dominated by manual labor. In contrast, highly adaptive and model-based approaches may offer a solution for manufacturing with a high degree of automation and high throughput while maintaining high precision. In this work a model-based automated assembly approach based on ray-tracing is presented. This process runs autonomously, and accounts for a wide range of functionality. It firstly identifies the sequence for an optimized assembly and secondly, generates and matches intermediate figures of merit to predict the overall optical functionality of the optical system. This process also takes into account the generation of a digital twin of the optical system, by mapping key-performance-indicators like the first and the second momentum of intensity into the optical model. This approach is verified by the automatic assembly of an anamorphic telescope within an assembly cell. By continuous measuring and mapping the key-performance-indicators into the optical model, the quality of the digital twin is determined. Moreover, by measuring the optical quality and geometrical parameters of the telescope, the precision of this approach is determined. Finally, the productivity of the process is evaluated by monitoring the speed of the different steps of the process.

Robotically Assembled Aerospace Structures: Digital Material Assembly using a Gantry-Type Assembler

NASA Technical Reports Server (NTRS)

Trinh, Greenfield; Copplestone, Grace; O'Connor, Molly; Hu, Steven; Nowak, Sebastian; Cheung, Kenneth; Jenett, Benjamin; Cellucci, Daniel

2017-01-01

This paper evaluates the development of automated assembly techniques for discrete lattice structures using a multi-axis gantry type CNC machine. These lattices are made of discrete components called digital materials. We present the development of a specialized end effector that works in conjunction with the CNC machine to assemble these lattices. With this configuration we are able to place voxels at a rate of 1.5 per minute. The scalability of digital material structures due to the incremental modular assembly is one of its key traits and an important metric of interest. We investigate the build times of a 5x5 beam structure on the scale of 1 meter (325 parts), 10 meters (3,250 parts), and 30 meters (9,750 parts). Utilizing the current configuration with a single end effector, performing serial assembly with a globally fixed feed station at the edge of the build volume, the build time increases according to a scaling law of n4, where n is the build scale. Build times can be reduced significantly by integrating feed systems into the gantry itself, resulting in a scaling law of n3. A completely serial assembly process will encounter time limitations as build scale increases. Automated assembly for digital materials can assemble high performance structures from discrete parts, and techniques such as built in feed systems, parallelization, and optimization of the fastening process will yield much higher throughput.

Robotically Assembled Aerospace Structures: Digital Material Assembly using a Gantry-Type Assembler

NASA Technical Reports Server (NTRS)

Trinh, Greenfield; Copplestone, Grace; O'Connor, Molly; Hu, Steven; Nowak, Sebastian; Cheung, Kenneth; Jenett, Benjamin; Cellucci, Daniel

2017-01-01

This paper evaluates the development of automated assembly techniques for discrete lattice structures using a multi-axis gantry type CNC machine. These lattices are made of discrete components called "digital materials." We present the development of a specialized end effector that works in conjunction with the CNC machine to assemble these lattices. With this configuration we are able to place voxels at a rate of 1.5 per minute. The scalability of digital material structures due to the incremental modular assembly is one of its key traits and an important metric of interest. We investigate the build times of a 5x5 beam structure on the scale of 1 meter (325 parts), 10 meters (3,250 parts), and 30 meters (9,750 parts). Utilizing the current configuration with a single end effector, performing serial assembly with a globally fixed feed station at the edge of the build volume, the build time increases according to a scaling law of n4, where n is the build scale. Build times can be reduced significantly by integrating feed systems into the gantry itself, resulting in a scaling law of n3. A completely serial assembly process will encounter time limitations as build scale increases. Automated assembly for digital materials can assemble high performance structures from discrete parts, and techniques such as built in feed systems, parallelization, and optimization of the fastening process will yield much higher throughput.

The self-assembled behavior of DNA bases on the interface.

PubMed

Liu, Lei; Xia, Dan; Klausen, Lasse H; Dong, Mingdong

2014-01-27

A successful example of self-assembly in a biological system is that DNA can be an excellent agent to self-assemble into desirable two and three-dimensional nanostructures in a well-ordered manner by specific hydrogen bonding interactions between the DNA bases. The self-assembly of DNA bases have played a significant role in constructing the hierarchical nanostructures. In this review article we will introduce the study of nucleic acid base self-assembly by scanning tunneling microscopy (STM) at vacuum and ambient condition (the liquid/solid interface), respectively. From the ideal condition to a more realistic environment, the self-assembled behaviors of DNA bases are introduced. In a vacuum system, the energetic advantages will dominate the assembly formation of DNA bases, while at ambient condition, more factors such as conformational freedom and the biochemical environment will be considered. Therefore, the assemblies of DNA bases at ambient condition are different from the ones obtained under vacuum. We present the ordered nanostructures formed by DNA bases at both vacuum and ambient condition. To construct and tailor the nanostructure through the interaction between DNA bases, it is important to understand the assembly behavior and features of DNA bases and their derivatives at ambient condition. The utilization of STM offers the advantage of investigating DNA base self-assembly with sub-molecular level resolution at the surface.

The Self-Assembled Behavior of DNA Bases on the Interface

PubMed Central

Liu, Lei; Xia, Dan; Klausen, Lasse H.; Dong, Mingdong

2014-01-01

A successful example of self-assembly in a biological system is that DNA can be an excellent agent to self-assemble into desirable two and three-dimensional nanostructures in a well-ordered manner by specific hydrogen bonding interactions between the DNA bases. The self-assembly of DNA bases have played a significant role in constructing the hierarchical nanostructures. In this review article we will introduce the study of nucleic acid base self-assembly by scanning tunneling microscopy (STM) at vacuum and ambient condition (the liquid/solid interface), respectively. From the ideal condition to a more realistic environment, the self-assembled behaviors of DNA bases are introduced. In a vacuum system, the energetic advantages will dominate the assembly formation of DNA bases, while at ambient condition, more factors such as conformational freedom and the biochemical environment will be considered. Therefore, the assemblies of DNA bases at ambient condition are different from the ones obtained under vacuum. We present the ordered nanostructures formed by DNA bases at both vacuum and ambient condition. To construct and tailor the nanostructure through the interaction between DNA bases, it is important to understand the assembly behavior and features of DNA bases and their derivatives at ambient condition. The utilization of STM offers the advantage of investigating DNA base self-assembly with sub-molecular level resolution at the surface. PMID:24473140

Creating Prebiotic Sanctuary: Self-Assembling Supramolecular Peptide Structures Bind and Stabilize RNA

NASA Astrophysics Data System (ADS)

Carny, Ohad; Gazit, Ehud

2011-04-01

Any attempt to uncover the origins of life must tackle the known `blind watchmaker problem'. That is to demonstrate the likelihood of the emergence of a prebiotic system simple enough to be formed spontaneously and yet complex enough to allow natural selection that will lead to Darwinistic evolution. Studies of short aromatic peptides revealed their ability to self-assemble into ordered and stable structures. The unique physical and chemical characteristics of these peptide assemblies point out to their possible role in the origins of life. We have explored mechanisms by which self-assembling short peptides and RNA fragments could interact together and go through a molecular co-evolution, using diphenylalanine supramolecular assemblies as a model system. The spontaneous formation of these self-assembling peptides under prebiotic conditions, through the salt-induced peptide formation (SIPF) pathway was demonstrated. These peptide assemblies possess the ability to bind and stabilize ribonucleotides in a sequence-depended manner, thus increase their relative fitness. The formation of these peptide assemblies is dependent on the homochirality of the peptide monomers: while homochiral peptides (L-Phe-L-Phe and D-Phe-D-Phe) self-assemble rapidly in aqueous environment, heterochiral diastereoisomers (L-Phe-D-Phe and D-Phe-L-Phe) do not tend to self-assemble. This characteristic consists with the homochirality of all living matter. Finally, based on these findings, we propose a model for the role of short self-assembling peptides in the prebiotic molecular evolution and the origin of life.

Creating prebiotic sanctuary: self-assembling supramolecular Peptide structures bind and stabilize RNA.

PubMed

Carny, Ohad; Gazit, Ehud

2011-04-01

Any attempt to uncover the origins of life must tackle the known 'blind watchmaker problem'. That is to demonstrate the likelihood of the emergence of a prebiotic system simple enough to be formed spontaneously and yet complex enough to allow natural selection that will lead to Darwinistic evolution. Studies of short aromatic peptides revealed their ability to self-assemble into ordered and stable structures. The unique physical and chemical characteristics of these peptide assemblies point out to their possible role in the origins of life. We have explored mechanisms by which self-assembling short peptides and RNA fragments could interact together and go through a molecular co-evolution, using diphenylalanine supramolecular assemblies as a model system. The spontaneous formation of these self-assembling peptides under prebiotic conditions, through the salt-induced peptide formation (SIPF) pathway was demonstrated. These peptide assemblies possess the ability to bind and stabilize ribonucleotides in a sequence-depended manner, thus increase their relative fitness. The formation of these peptide assemblies is dependent on the homochirality of the peptide monomers: while homochiral peptides (L-Phe-L-Phe and D-Phe-D-Phe) self-assemble rapidly in aqueous environment, heterochiral diastereoisomers (L-Phe-D-Phe and D-Phe-L-Phe) do not tend to self-assemble. This characteristic consists with the homochirality of all living matter. Finally, based on these findings, we propose a model for the role of short self-assembling peptides in the prebiotic molecular evolution and the origin of life.

Proton Electrostatic Analyzer.

DTIC Science & Technology

1983-02-01

Detector Assembly ......................................... 11 2.2 Analyzer (Energy Selector) Assembly............................ 12 2.3 Collimator...Spectrometer assembly ........................................ 13 2.2 Base plate .................................................. 14 - ~ 2.3 Detector ... sensitive vehicle systems. Space objects undergo differential charging due to variations in physical properties among their surface regions. The rate and

Installing the ARFTA (Advanced Recycle Filter Tank Assembly)

NASA Image and Video Library

2011-10-10

ISS029-E-021648 (10 Oct. 2011) --- NASA astronaut Mike Fossum, Expedition 29 commander, installs the Advanced Recycle Filter Tank Assembly (ARFTA) at the Urine Processor Assembly / Water Recovery System (UPA WRS) in the Destiny laboratory of the International Space Station.

Gas separation membrane module assembly

DOEpatents

Wynn, Nicholas P [Palo Alto, CA; Fulton, Donald A [Fairfield, CA

2009-03-31

A gas-separation membrane module assembly and a gas-separation process using the assembly. The assembly includes a set of tubes, each containing gas-separation membranes, arranged within a housing. The housing contains a tube sheet that divides the space within the housing into two gas-tight spaces. A permeate collection system within the housing gathers permeate gas from the tubes for discharge from the housing.

Mitochondrial assembly receptor expression is an independent prognosticator for patients with oral tongue squamous cell carcinoma.

PubMed

Su, Yan-Ye; Chen, Chang-Han; Chien, Chih-Yen; Lin, Wei-Che; Huang, Wan-Ting; Li, Shau-Hsuan

2017-01-01

Recent evidence suggests that the local renin-angiotensin system has been implicated in various malignancies. The mitochondrial assembly receptor is a newly identified receptor for angiotensin peptides, angiotensin-(1-7), and has an important role in the renin-angiotensin system. However, the role of the mitochondrial assembly receptor in the prognosis of cancer patients remains unclear. The aim of this study was to evaluate the significance of mitochondrial assembly receptor signaling in the prognosis of oral tongue squamous cell carcinoma. Mitochondrial assembly receptor immunohistochemistry was examined in 151 oral tongue squamous cell carcinoma patients and was correlated with treatment outcome. The functional relevance of the mitochondrial assembly receptor in oral tongue squamous cell carcinoma cell lines was evaluated by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide reduction and bromodeoxyuridine incorporation assays. Mitochondrial assembly receptor overexpression was significantly correlated with early pathological T classification ( p=0.029) and the absence of extracapsular spread ( p=0.039). Univariate analyses demonstrated that mitochondrial assembly receptor overexpression was significantly associated with superior overall survival ( p=0.012). In multivariate comparison, mitochondrial assembly receptor overexpression remained independently associated with superior overall survival ( p=0.008, hazard ratio=1.862). In vitro, angiotensin-(1-7) suppressed the cell growth in oral tongue squamous cell carcinoma cells, and this response was reversed by the mitochondrial assembly receptor antagonist, A779. Mitochondrial assembly receptor expression is independently associated with the prognosis of oral tongue squamous cell carcinoma patients. These findings suggest that mitochondrial assembly receptor signaling may be a promising novel target for oral tongue squamous cell carcinoma.

Magnetically-induced solid-phase microextraction fiber actuation system for quantitative headspace and liquid sampling

DOEpatents

Harvey, Chris; Carter, Jerry; Chambers, David M.

2017-05-23

A magnetically-induced SPME fiber actuation system includes a SPME fiber holder and a SPME fiber holder actuator, for holding and magnetically actuating a SPME fiber assembly. The SPME fiber holder has a plunger with a magnetic material to which the SPME fiber assembly is connected, and the magnetic SPME fiber holder actuator has an elongated barrel with a loading chamber for receiving the SPME fiber assembly-connected SPME fiber holder, and an external magnet which induces axial motion of the magnetic material of the plunger to extend/retract the SPME fiber from/into the protective needle of the SPME fiber assembly.

X-ray source assembly having enhanced output stability, and fluid stream analysis applications thereof

DOEpatents

Radley, Ian; Bievenue, Thomas J.; Burdett Jr., John H.; Gallagher, Brian W.; Shakshober, Stuart M.; Chen, Zewu; Moore, Michael D.

2007-04-24

An x-ray source assembly (2700) and method of operation are provided having enhanced output stability. The assembly includes an anode (2125) having a source spot upon which electrons (2120) impinge and a control system (2715/2720) for controlling position of the anode source spot relative to an output structure. The control system can maintain the anode source spot location relative to the output structure (2710) notwithstanding a change in one or more operating conditions of the x-ray source assembly. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.

Flow-Based Assembly of Layer-by-Layer Capsules through Tangential Flow Filtration.

PubMed

Björnmalm, Mattias; Roozmand, Ali; Noi, Ka Fung; Guo, Junling; Cui, Jiwei; Richardson, Joseph J; Caruso, Frank

2015-08-25

Layer-by-layer (LbL) assembly on nano- and microparticles is of interest for a range of applications, including catalysis, optics, sensors, and drug delivery. One current limitation is the standard use of manual, centrifugation-based (pellet/resuspension) methods to perform the layering steps, which can make scalable, highly controllable, and automatable production difficult to achieve. Here, we develop a fully flow-based technique using tangential flow filtration (TFF) for LbL assembly on particles. We demonstrate that multilayered particles and capsules with different sizes (from micrometers to submicrometers in diameter) can be assembled on different templates (e.g., silica and calcium carbonate) using several polymers (e.g., poly(allylamine hydrochloride), poly(styrenesulfonate), and poly(diallyldimethylammonium chloride)). The full system only contains fluidic components routinely used (and automated) in industry, such as pumps, tanks, valves, and tubing in addition to the TFF filter modules. Using the TFF LbL system, we also demonstrate the centrifugation-free assembly, including core dissolution, of drug-loaded capsules. The well-controlled, integrated, and automatable nature of the TFF LbL system provides scientific, engineering, and practical processing benefits, making it valuable for research environments and potentially useful for translating LbL assembled particles into diverse applications.

Mechanisms Underlying the Active Self-Assembly of Microtubule Rings and Spools.

PubMed

VanDelinder, Virginia; Brener, Stephanie; Bachand, George D

2016-03-14

Active self-assembly offers a powerful route for the creation of dynamic multiscale structures that are presently inaccessible with standard microfabrication techniques. One such system uses the translation of microtubule filaments by surface-tethered kinesin to actively assemble nanocomposites with bundle, ring, and spool morphologies. Attempts to observe mechanisms involved in this active assembly system have been hampered by experimental difficulties with performing observation during buffer exchange and photodamage from fluorescent excitation. In the present work, we used a custom microfluidic device to remove these limitations and directly study ring/spool formation, including the earliest events (nucleation) that drive subsequent nanocomposite assembly. Three distinct formation events were observed: pinning, collisions, and induced curvature. Of these three, collisions accounted for the majority of event leading to ring/spool formation, while the rate of pinning was shown to be dependent on the amount of photodamage in the system. We further showed that formation mechanism directly affects the diameter and rotation direction of the resultant rings and spools. Overall, the fundamental understanding described in this work provides a foundation by which the properties of motor-driven, actively assembled nanocomposites may be tailored toward specific applications.

Mechanisms underlying the active self-assembly of microtubule rings and spools

DOE PAGES

VanDelinder, Virginia; Brener, Stephanie; Bachand, George D.

2016-02-04

Here, active self-assembly offers a powerful route for the creation of dynamic multiscale structures that are presently inaccessible with standard microfabrication techniques. One such system uses the translation of microtubule filaments by surface-tethered kinesin to actively assemble nanocomposites with bundle, ring, and spool morphologies. Attempts to observe mechanisms involved in this active assembly system have been hampered by experimental difficulties with performing observation during buffer exchange and photodamage from fluorescent excitation. In the present work, we used a custom microfluidic device to remove these limitations and directly study ring/spool formation, including the earliest events (nucleation) that drive subsequent nanocomposite assembly.more » Three distinct formation events were observed: pinning, collisions, and induced curvature. Of these three, collisions accounted for the majority of event leading to ring/spool formation, while the rate of pinning was shown to be dependent on the amount of photodamage in the system. We further showed that formation mechanism directly affects the diameter and rotation direction of the resultant rings and spools. Overall, the fundamental understanding described in this work provides a foundation by which the properties of motor-driven, actively assembled nanocomposites may be tailored toward specific applications.« less

Diversity in virus assembly: biology makes things complicated

NASA Astrophysics Data System (ADS)

Zlotnick, Adam

2008-03-01

Icosahedral viruses have an elegance of geometry that implies a general path of assembly. However, structure alone provides insufficient information. Cowpea Chlorotic Mottle Virus (CCMV), an important system for studying virus assembly, consists of 90 coat protein (CP) homodimers condensed around an RNA genome. The crystal structure (Speir et al, 1995) reveals that assembly causes burial of hydrophobic surface and formation of β hexamers, the intertwining of N-termini of the CPs surrounding a quasi-sixfold. This structural view leads to reasonable and erroneous predictions: (i) CCMV capsids are extremely stable, and (ii) β hexamer formation is critical to assembly. Experimentally, we have found that capsids are based on a network of extremely weak (4-5 kT) pairwise interactions and that pentamer formation is the critical step in assembly kinetics. Because of the fragility of CP-Cp interaction, we can redirect assembly to generate and dissociate tubular nanostructures. The dynamic behavior of CCMV reflects the requirements and peculiarities of an evolved biological system; it does not necessarily reflect the behavior predicted from a more static picture of the virus.

BWR ASSEMBLY SOURCE TERMS FOR WASTE PACKAGE DESIGN

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

T.L. Lotz

1997-02-15

This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) to provide boiling water reactor (BWR) assembly radiation source term data for use during Waste Package (WP) design. The BWR assembly radiation source terms are to be used for evaluation of radiolysis effects at the WP surface, and for personnel shielding requirements during assembly or WP handling operations. The objectives of this evaluation are to generate BWR assembly radiation source terms that bound selected groupings of BWR assemblies, with regard to assembly average burnup and cooling time, which comprise the anticipated MGDS BWR commercialmore » spent nuclear fuel (SNF) waste stream. The source term data is to be provided in a form which can easily be utilized in subsequent shielding/radiation dose calculations. Since these calculations may also be used for Total System Performance Assessment (TSPA), with appropriate justification provided by TSPA, or radionuclide release rate analysis, the grams of each element and additional cooling times out to 25 years will also be calculated and the data included in the output files.« less

PEO Ammunition Systems Portfolio Book 2012-2013

DTIC Science & Technology

2011-02-02

assembly. Aluminum ogive contains firing pin, a rubber anti-creep spring and M550 fuze escapement assembly and is threaded to projectile body...51 The Mortar Weapons and Fire Control Family M95/M96 Mortar Fire Control System (MFCS) – Mounted...52 M150/M151 Mortar Fire Control System Dismounted (MFCS-D

Drive system for the retraction/extension of variable diameter rotor systems

NASA Technical Reports Server (NTRS)

Gmirya, Yuriy (Inventor)

2003-01-01

A drive system for a variable diameter rotor (VDR) system includes a plurality of rotor blade assemblies with inner and outer rotor blade segments. The outer blade segment being telescopically mounted to the inner blade segment. The VDR retraction/extension system includes a drive housing mounted at the root of each blade. The housing supports a spool assembly, a harmonic gear set and an electric motor. The spool assembly includes a pair of counter rotating spools each of which drive a respective cable which extends through the interior of the inboard rotor blade section and around a pulley mounted to the outboard rotor blade section. In operation, the electric motor drives the harmonic gear set which rotates the counter rotating spools. Rotation of the spools causes the cables to be wound onto or off their respective spool consequently effecting retraction/extension of the pulley and the attached outboard rotor blade section relative the inboard rotor blade section. As each blade drive system is independently driven by a separate electrical motor, each independent VDR blade assembly is independently positionable.

Measurement of Thermal Conductivities of Two Cryoprotective Agent Solutions for Vitreous Cryopreservation of Organs at the Temperature Range of 77 K-300 K Using a Thermal Sensor Made of Microscale Enamel Copper Wire.

PubMed

Li, Yufang; Zhao, Gang; Hossain, S M Chapal; Panhwar, Fazil; Sun, Wenyu; Kong, Fei; Zang, Chuanbao; Jiang, Zhendong

2017-06-01

Biobanking of organs by cryopreservation is an enabling technology for organ transplantation. Compared with the conventional slow freezing method, vitreous cryopreservation has been regarded to be a more promising approach for long-term storage of organs. The major challenges to vitrification are devitrification and recrystallization during the warming process, and high concentrations of cryoprotective agents (CPAs) induced metabolic and osmotic injuries. For a theoretical model based optimization of vitrification, thermal properties of CPA solutions are indispensable. In this study, the thermal conductivities of M22 and vitrification solution containing ethylene glycol and dimethyl sulfoxide (two commonly used vitrification solutions) were measured using a self-made microscaled hot probe with enameled copper wire at the temperature range of 77 K-300 K. The data obtained by this study will further enrich knowledge of the thermal properties for CPA solutions at low temperatures, as is of primary importance for optimization of vitrification.

Cyclic RGD peptidomimetics containing 4- and 5-amino-cyclopropane pipecolic acid (CPA) templates as dual αVβ3 and α5β1 integrin ligands.

PubMed

Sernissi, Lorenzo; Trabocchi, Andrea; Scarpi, Dina; Bianchini, Francesca; Occhiato, Ernesto G

2016-02-15

4-Amino- and 5-amino-cyclopropane pipecolic acids (CPAs) with cis relative stereochemistry between the carboxylic and amino groups were used as templates to prepare cyclic peptidomimetics containing the RGD sequence as possible integrin binders. The peptidomimetic c(RGD8) built on the 5-amino-CPA displayed an inhibition activity (IC50=2.4nM) toward the αvβ3 integrin receptor (expressed in M21 human melanoma cell line) comparable to that of the most potent antagonists reported so far and it was ten times more active than the corresponding antagonist c(RGD7) derived from the isomeric 4-amino-CPA. Both compounds were also nanomolar ligands of the α5β1 integrin (expressed in human erythroleukemia cell line K562). These results suggest that the CPA-derived templates are suitable for the preparation of dual αvβ3 and α5β1 ligands to suppress integrin-mediated events as well as for targeted drug delivery in cancer therapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

21st International Conference on DNA Computing and Molecular Programming: 8.1 Biochemistry

DTIC Science & Technology

include information storage and biological applications of DNA systems, biomolecular chemical reaction networks, applications of self -assembled DNA...nanostructures, tile self -assembly and computation, principles and models of self -assembly, and strand displacement and biomolecular circuits. The fund

24 CFR 3280.702 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... conditioning self contained system means a comfort cooling appliance combining the condenser section... assembly composed of listed factory-built components assembled in accordance with the terms of listing to... means that portion of a manufactured home heater flue or vent assembly, including the cap, insulating...

Earth Sensor Assembly for the Tropical Rainfall Measuring Mission Observatory

NASA Technical Reports Server (NTRS)

Prince, Steven S.; Hoover, James M.

1995-01-01

EDO Corporation/Barnes Engineering Division (BED) has provided the Tropical Rainfall Measurement Mission (TRMM) Earth Sensor Assembly (ESA), a key element in the TRMM spacecraft's attitude control system. This report documents the history, design, fabrication, assembly, and test of the ESA.

Modular robotic assembly of small devices.

PubMed

Frauenfelder, M

2000-01-01

The use of robots for the automatic assembly of devices of up to 100 x 100 x 100 mm is relatively uncommon today. Insufficient return on investment and the long lead times that are required have been limiting factors. Innovations in vision technology have led to the development of robotic assembly systems that employ flexible part-feeding. The benefits of these systems are described, which suggest that better ratios of price to productivity and deployment times are now achievable.

A shuttle and space station manipulator system for assembly, docking, maintenance, cargo handling and spacecraft retrieval (preliminary design). Volume 3: Concept analysis. Part 1: Technical

NASA Technical Reports Server (NTRS)

1972-01-01

Information backing up the key features of the manipulator system concept and detailed technical information on the subsystems are presented. Space station assembly and shuttle cargo handling tasks are emphasized in the concept analysis because they involve shuttle berthing, transferring the manipulator boom between shuttle and station, station assembly, and cargo handling. Emphasis is also placed on maximizing commonality in the system areas of manipulator booms, general purpose end effectors, control and display, data processing, telemetry, dedicated computers, and control station design.

Principles of designing cyber-physical system of producing mechanical assembly components at Industry 4.0 enterprise

NASA Astrophysics Data System (ADS)

Gurjanov, A. V.; Zakoldaev, D. A.; Shukalov, A. V.; Zharinov, I. O.

2018-03-01

The task of developing principles of cyber-physical system constitution at the Industry 4.0 company of the item designing components of mechanical assembly production is being studied. The task has been solved by analyzing the components and technologies, which have some practical application in the digital production organization. The list of components has been defined and the authors proposed the scheme of the components and technologies interconnection in the Industry 4.0 of mechanical assembly production to make an uninterrupted manufacturing route of the item designing components with application of some cyber-physical systems.

Forced response of mistuned bladed disk assemblies

NASA Technical Reports Server (NTRS)

Watson, Brian C.; Kamat, Manohar P.; Murthy, Durbha V.

1993-01-01

A complete analytic model of mistuned bladed disk assemblies, designed to simulate the dynamical behavior of these systems, is analyzed. The model incorporates a generalized method for describing the mistuning of the assembly through the introduction of specific mistuning modes. The model is used to develop a computational bladed disk assembly model for a series of parametric studies. Results are presented demonstrating that the response amplitudes of bladed disk assemblies depend both on the excitation mode and on the mistune mode.

Solution deposition assembly

DOEpatents

Roussillon, Yann; Scholz, Jeremy H; Shelton, Addison; Green, Geoff T; Utthachoo, Piyaphant

2014-01-21

Methods and devices are provided for improved deposition systems. In one embodiment of the present invention, a deposition system is provided for use with a solution and a substrate. The system comprises of a solution deposition apparatus; at least one heating chamber, at least one assembly for holding a solution over the substrate; and a substrate curling apparatus for curling at least one edge of the substrate to define a zone capable of containing a volume of the solution over the substrate. In another embodiment of the present invention, a deposition system for use with a substrate, the system comprising a solution deposition apparatus; at heating chamber; and at least assembly for holding solution over the substrate to allow for a depth of at least about 0.5 microns to 10 mm.

Self-assembly of proteins into a three-dimensional multilayer system: investigation of the surface of the human fungal pathogen Aspergillus fumigatus.

PubMed

Zykwinska, Agata; Pihet, Marc; Radji, Sadia; Bouchara, Jean-Philippe; Cuenot, Stéphane

2014-06-01

Hydrophobins are small surface active proteins that fulfil a wide spectrum of functions in fungal growth and development. The human fungal pathogen Aspergillus fumigatus expresses RodA hydrophobins that self-assemble on the outer conidial surface into tightly organized nanorods known as rodlets. AFM investigation of the conidial surface allows us to evidence that RodA hydrophobins self-assemble into rodlets through bilayers. Within bilayers, hydrophilic domains of hydrophobins point inward, thus making a hydrophilic core, while hydrophobic domains point outward. AFM measurements reveal that several rodlet bilayers are present on the conidial surface thus showing that proteins self-assemble into a complex three-dimensional multilayer system. The self-assembly of RodA hydrophobins into rodlets results from attractive interactions between stacked β-sheets, which conduct to a final linear cross-β spine structure. A Monte Carlo simulation shows that anisotropic interactions are the main driving forces leading the hydrophobins to self-assemble into parallel rodlets, which are further structured in nanodomains. Taken together, these findings allow us to propose a mechanism, which conducts RodA hydrophobins to a highly ordered rodlet structure. The mechanism of hydrophobin assembly into rodlets offers new prospects for the development of more efficient strategies leading to disruption of rodlet formation allowing a rapid detection of the fungus by the immune system. Copyright © 2014 Elsevier B.V. All rights reserved.

Design requirements for SRB production control system. Volume 1: Study background and overview

NASA Technical Reports Server (NTRS)

1981-01-01

The solid rocket boosters assembly environment is described in terms of the contraints it places upon an automated production control system. The business system generated for the SRB assembly and the computer system which meets the business system requirements are described. The selection software process and modifications required to the recommended software are addressed as well as the hardware and configuration requirements necessary to support the system.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred J; Motala, Michael; Ahn, Jong-Hyun; Park, Sang-Il; Yu, Chang-Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung

2014-05-13

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John [Champaign, IL; Nuzzo, Ralph [Champaign, IL; Meitl, Matthew [Durham, NC; Menard, Etienne [Durham, NC; Baca, Alfred J [Urbana, IL; Motala, Michael [Champaign, IL; Ahn, Jong-Hyun [Suwon, KR; Park, Sang-II [Savoy, IL; Yu,; Chang-Jae, [Urbana, IL; Ko, Heung-Cho [Gwangju, KR; Stoykovich,; Mark, [Dover, NH; Yoon, Jongseung [Urbana, IL

2011-07-05

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred; Motala, Michael; Ahn, Jong -Hyun; Park, Sang -Il; Yu, Chang -Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung

2015-08-25

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred; Motala, Michael; Ahn, Jong-Hyun; Park, Sang-Il; Yu, Chang-Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung

2017-03-21

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Virtual commissioning of automated micro-optical assembly

NASA Astrophysics Data System (ADS)

Schlette, Christian; Losch, Daniel; Haag, Sebastian; Zontar, Daniel; Roßmann, Jürgen; Brecher, Christian

2015-02-01

In this contribution, we present a novel approach to enable virtual commissioning for process developers in micro-optical assembly. Our approach aims at supporting micro-optics experts to effectively develop assisted or fully automated assembly solutions without detailed prior experience in programming while at the same time enabling them to easily implement their own libraries of expert schemes and algorithms for handling optical components. Virtual commissioning is enabled by a 3D simulation and visualization system in which the functionalities and properties of automated systems are modeled, simulated and controlled based on multi-agent systems. For process development, our approach supports event-, state- and time-based visual programming techniques for the agents and allows for their kinematic motion simulation in combination with looped-in simulation results for the optical components. First results have been achieved for simply switching the agents to command the real hardware setup after successful process implementation and validation in the virtual environment. We evaluated and adapted our system to meet the requirements set by industrial partners-- laser manufacturers as well as hardware suppliers of assembly platforms. The concept is applied to the automated assembly of optical components for optically pumped semiconductor lasers and positioning of optical components for beam-shaping

General view taken inside of an assembly bay of the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view taken inside of an assembly bay of the Vehicle Assembly Building at the Kennedy Space Center. This view shows the Orbiter Discovery being lowered into position in preparation for being mated to the External Tank/Solid Rocket Booster assembly on the Mobile Launch Platform. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

AutoAssemblyD: a graphical user interface system for several genome assemblers.

PubMed

Veras, Adonney Allan de Oliveira; de Sá, Pablo Henrique Caracciolo Gomes; Azevedo, Vasco; Silva, Artur; Ramos, Rommel Thiago Jucá

2013-01-01

Next-generation sequencing technologies have increased the amount of biological data generated. Thus, bioinformatics has become important because new methods and algorithms are necessary to manipulate and process such data. However, certain challenges have emerged, such as genome assembly using short reads and high-throughput platforms. In this context, several algorithms have been developed, such as Velvet, Abyss, Euler-SR, Mira, Edna, Maq, SHRiMP, Newbler, ALLPATHS, Bowtie and BWA. However, most such assemblers do not have a graphical interface, which makes their use difficult for users without computing experience given the complexity of the assembler syntax. Thus, to make the operation of such assemblers accessible to users without a computing background, we developed AutoAssemblyD, which is a graphical tool for genome assembly submission and remote management by multiple assemblers through XML templates. AssemblyD is freely available at https://sourceforge.net/projects/autoassemblyd. It requires Sun jdk 6 or higher.

Design and simulation of integration system between automated material handling system and manufacturing layout in the automotive assembly line

NASA Astrophysics Data System (ADS)

Seha, S.; Zamberi, J.; Fairu, A. J.

2017-10-01

Material handling system (MHS) is an important part for the productivity plant and has recognized as an integral part of today’s manufacturing system. Currently, MHS has growth tremendously with its technology and equipment type. Based on the case study observation, the issue involving material handling system contribute to the reduction of production efficiency. This paper aims to propose a new design of integration between material handling and manufacturing layout by investigating the influences of layout and material handling system. A method approach tool using Delmia Quest software is introduced and the simulation result is used to assess the influences of the integration between material handling system and manufacturing layout in the performance of automotive assembly line. The result show, the production of assembly line output increases more than 31% from the current system. The source throughput rate average value went up to 252 units per working hour in model 3 and show the effectiveness of the pick-to-light system as efficient storage equipment. Thus, overall result shows, the application of AGV and the pick-to-light system gave a large significant effect in the automotive assembly line. Moreover, the change of layout also shows a large significant improvement to the performance.

Influence of the Helicopter Time Domain Electromagnetic System Off-Time Response by the Transmitter Assembly

NASA Astrophysics Data System (ADS)

Vetrov, A.; Mejzr, I.

2010-12-01

While developing a new Helicopter Time Domain Electromagnetic system (P-THEM), Pico Envirotec Inc (PEI) has studied the effect of the transmitter assembly on the acquired data. The P-THEM system consists of a loop-transmitter assembly, powered by a motor generator, 3-axis coil receiver attached at the midpoint of a tow cable and an additional Z-axis (dB/dt) receiver installed on the rear section of the transmitter loop. The system is towed by a helicopter on a 230 foot long tow cable. The transmitter loop is designed to produce a peak magnetic moment of approximately 250,000 NIA with a base frequency of 30 Hz (adjustable to 25Hz) and a quarter length duty cycle (4 ms on-time). The secondary field acquired with a dB/dt receiver coil consists of a ground response and a system response: SF=Rg+Rsys, where SF - the secondary field, Rg - ground response, Rsys - system response. The system itself, especially the transmitter assembly, being a conductor in an induced magnetic field, creates a magnetic anomaly. The influence of the transmitter assembly anomaly on the received signal depends on the position of the receiver coil against the transmitter, the intensity of on-time pulse and transmitter electro-magnetic properties. At the same time, the ground response acquired with a receiver coil depends on the length and the moment of transmitter pulse, as well as the position and distance of the receiver coil from the ground. This can be for vertical field (Z) receiver coil described as RXz(t)=e(t)pz(t)Rgz(t)+d(t)k(t)j(t)TXz(t), where RXz(t) - receiver response, e(t) - elevation of the receiver over the ground, pz(t) - horizontal projection of the receiver coil, Rgz(t) - vertical component of ground response, d(t) - distance (elevation) between the receiver coil and the transmitter loop, k(t) - the position of the receiver in the transmitter field, j(t) - the transmitter assembly electromagnetic properties, TXz(t) -transmitter field (Primary field on-time, and transmitter assembly response off-time). Changes in the electromagnetic properties of the transmitter loop and mechanical vibrations of the transmitter and receiver are much lower frequency in comparison with the base frequency and can be omitted from consideration of a one cycle length period. The transmitter assembly response has to be subtracted from acquired off-time decay for a correct interpretation of ground response. The transmitter influence is very low when the receiving coil is placed far away. However, the transmitter influence is very important when the receiver is close to the transmitter assembly due to the transmitter anomaly decay which then becomes greater than the ground response. The transmitter assembly off-time response can be registered when the system is flown at a sufficiently high altitude and it is not affected by ground conductors. A number of experiments were conducted to determine the transmitter influence content in the acquired data. The secondary dB/dt receiver installed at different elevations over the transmitter loop in test flights It showed the influence change of the transmitter assembly on the acquired secondary field (OFF-time) dependent upon the distance between the transmitter assembly and the receiver loop.

An assembly system based on industrial robot with binocular stereo vision

NASA Astrophysics Data System (ADS)

Tang, Hong; Xiao, Nanfeng

2017-01-01

This paper proposes an electronic part and component assembly system based on an industrial robot with binocular stereo vision. Firstly, binocular stereo vision with a visual attention mechanism model is used to get quickly the image regions which contain the electronic parts and components. Secondly, a deep neural network is adopted to recognize the features of the electronic parts and components. Thirdly, in order to control the end-effector of the industrial robot to grasp the electronic parts and components, a genetic algorithm (GA) is proposed to compute the transition matrix and the inverse kinematics of the industrial robot (end-effector), which plays a key role in bridging the binocular stereo vision and the industrial robot. Finally, the proposed assembly system is tested in LED component assembly experiments, and the results denote that it has high efficiency and good applicability.

Actively controlled vibration welding system and method

DOEpatents

Cai, Wayne W.; Kang, Bongsu; Tan, Chin-An

2013-04-02

A vibration welding system includes a controller, welding horn, an active material element, and anvil assembly. The assembly may include an anvil body connected to a back plate and support member. The element, e.g., a piezoelectric stack or shape memory alloy, is positioned with respect to the assembly. The horn vibrates in a desirable first direction to form a weld on a work piece. The element controls any vibrations in a second direction by applying calibrated response to the anvil body in the second direction. A method for controlling undesirable vibrations in the system includes positioning the element with respect to the anvil assembly, connecting the anvil body to the support member through the back plate, vibrating the horn in a desirable first direction, and transmitting an input signal to the element to control vibration in an undesirable second direction.

General view of a fully assembled Solid Rocket Booster sitting ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of a fully assembled Solid Rocket Booster sitting atop the Mobile Launch Platform in the Vehicle Assembly Building at Kennedy Space Center - Space Transportation System, Solid Rocket Boosters, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Electrorefiner system for recovering purified metal from impure nuclear feed material

DOEpatents

Berger, John F.; Williamson, Mark A.; Wiedmeyer, Stanley G.; Willit, James L.; Barnes, Laurel A.; Blaskovitz, Robert J.

2015-10-06

An electrorefiner system according to a non-limiting embodiment of the present invention may include a vessel configured to maintain a molten salt electrolyte and configured to receive a plurality of alternately arranged cathode and anode assemblies. The anode assemblies are configured to hold an impure nuclear feed material. Upon application of the power system, the impure nuclear feed material is anodically dissolved and a purified metal is deposited on the cathode rods of the cathode assemblies. A scraper is configured to dislodge the purified metal deposited on the cathode rods. A conveyor system is disposed at a bottom of the vessel and configured to remove the dislodged purified metal from the vessel.

A Carbon Dioxide Bubble-Induced Vortex Triggers Co-Assembly of Nanotubes with Controlled Chirality.

PubMed

Zhang, Ling; Zhou, Laicheng; Xu, Na; Ouyang, Zhenjie

2017-07-03

It is challenging to prepare co-organized nanotube systems with controlled nanoscale chirality in an aqueous liquid flow field. Such systems are responsive to a bubbled external gas. A liquid vortex induced by bubbling carbon dioxide (CO 2 ) gas was used to stimulate the formation of nanotubes with controlled chirality; two kinds of achiral cationic building blocks were co-assembled in aqueous solution. CO 2 -triggered nanotube formation occurs by formation of metastable intermediate structures (short helical ribbons and short tubules) and by transition from short tubules to long tubules in response to chirality matching self-assembly. Interestingly, the chirality sign of these assemblies can be selected for by the circulation direction of the CO 2 bubble-induced vortex during the co-assembly process. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Plasticity of an Amorphous Assembly of Elastic Gel Beads

NASA Astrophysics Data System (ADS)

Grosshans, D.; Knaebel, A.; Lequeux, F.

1995-01-01

We have studied the rheological properties of an assembly of swollen gel beads in a lack of solvent. The system is an amorphous assembly of packed soft spheres in a given volume. We have studied the plastic behavior of the system, and interpreted it in terms of bead rearrangements within the assembly. Nous avons étudié les propriétés rhéologiques d'un assemblage de billes de gel gonflées en défaut de solvant. Le système est donc une assemblée amorphe de sphères molles écrasées à volume total constant. Nous avons étudié divers aspects du comportement plastique et nous l'avons interprété en termes de réorganisations de billes dans l'assemblage.

Flexture plate motion-transfer mechanism, beam-splitter assembly, and interferometer incorporating the same

DOEpatents

Carangelo, R.M.; Dettori, M.D.; Grigely, L.J.; Murray, T.C.; Solomon, P.R.; Dine, C.P. Van; Wright, D.D.

1996-01-23

A multiplicity of one-piece flexure plates are assembled in pairs to provide a support system on which a retroreflector may be mounted for reciprocal motion. Combined with balance bodies, the flexure plates provide a support system having portions that are dynamically and statically balanced with one another, irrespective of orientation, so as to thereby immunize the unit against extraneous forces. The motion transfer assembly is especially adapted for use to support a moving retroreflector in a two-arm interferometer that may further include a beamsplitter assembly constructed from a one-piece, integrally formed body, the body having convergent, optically flat planar surfaces of specular reflectance, and means for adjustably mounting a beamsplitter therein. The spectrometer is of modular construction, and employs an integrated clocking sub-assembly as well as a light-weight voice-coil motor. 15 figs.

Flexture plate motion-transfer mechanism, beam-splitter assembly, and interferometer incorporating the same

DOEpatents

Carangelo, Robert M.; Dettori, Mark D.; Grigely, Lawrence J.; Murray, Terence C.; Solomon, Peter R.; Van Dine, C. Peter; Wright, David D.

1996-01-01

A multiplicity of one-piece flexure plates are assembled in pairs to provide a support system on which a retroreflector may be mounted for reciprocal motion. Combined with balance bodies, the flexure plates provide a support system having portions that are dynamically and statically balanced with one another, irrespective of orientation, so as to thereby immunize the unit against extraneous forces. The motion transfer assembly is especially adapted for use to support a moving retroreflector in a two-arm interferometer that may further include a beamsplitter assembly constructed from a one-piece, integrally formed body, the body having convergent, optically flat planar surfaces of specular reflectance, and means for adjustably mounting a beamsplitter therein. The spectrometer is of modular construction, and employs an integrated clocking sub-assembly as well as a light-weight voice-coil motor.

Naval Remote Ocean Sensing System (NROSS) study

NASA Technical Reports Server (NTRS)

1983-01-01

A set of hardware similar to the SEASAT A configuration requirement, suitable for installation and operation aboard a NOAA-D bus and a budgetary cost for one (1) protoflight model was provided. The scatterometer sensor is conceived as one of several sensors for the Navy Remote Ocean Sensing System (NROSS) Satellite Program. Deliverables requested were to include a final report with appropriate sketches and block diagrams showing the scatterometer design/configuration and a budgetary cost for all labor and materials to design, fabricate, test, and integrate this hardware into a NOAA-D satellite bus. This configuration consists of two (2) hardware assembles - a transmitter/receiver (T/R) assembly and an integrated electronics assembly (IEA). The T/R assembly as conceived is best located at the extreme opposite end of the satellite away from the solar array assembly and oriented in position to enable one surface of the assembly to have unobstructed exposure to space. The IEA is planned to be located at the bottom (Earth viewing) side of the satellite and requires a radiating plate.

Development and verification testing of automation and robotics for assembly of space structures

NASA Technical Reports Server (NTRS)

Rhodes, Marvin D.; Will, Ralph W.; Quach, Cuong C.

1993-01-01

A program was initiated within the past several years to develop operational procedures for automated assembly of truss structures suitable for large-aperture antennas. The assembly operations require the use of a robotic manipulator and are based on the principle of supervised autonomy to minimize crew resources. A hardware testbed was established to support development and evaluation testing. A brute-force automation approach was used to develop the baseline assembly hardware and software techniques. As the system matured and an operation was proven, upgrades were incorprated and assessed against the baseline test results. This paper summarizes the developmental phases of the program, the results of several assembly tests, the current status, and a series of proposed developments for additional hardware and software control capability. No problems that would preclude automated in-space assembly of truss structures have been encountered. The current system was developed at a breadboard level and continued development at an enhanced level is warranted.

Interset: A natural language interface for teleoperated robotic assembly of the EASE space structure

NASA Technical Reports Server (NTRS)

Boorsma, Daniel K.

1989-01-01

A teleoperated robot was used to assemble the Experimental Assembly of Structures in Extra-vehicular activity (EASE) space structure under neutral buoyancy conditions, simulating a telerobot performing structural assembly in the zero gravity of space. This previous work used a manually controlled teleoperator as a test bed for system performance evaluations. From these results several Artificial Intelligence options were proposed. One of these was further developed into a real time assembly planner. The interface for this system is effective in assembling EASE structures using windowed graphics and a set of networked menus. As the problem space becomes more complex and hence the set of control options increases, a natural language interface may prove to be beneficial to supplement the menu based control strategy. This strategy can be beneficial in situations such as: describing the local environment, maintaining a data base of task event histories, modifying a plan or a heuristic dynamically, summarizing a task in English, or operating in a novel situation.

Launch Lock Assemblies with Reduced Preload and Spacecraft Isolation Systems Including the Same

NASA Technical Reports Server (NTRS)

Barber, Tim Daniel (Inventor); Young, Ken (Inventor); Hindle, Timothy (Inventor)

2016-01-01

Launch lock assemblies with reduced preload are provided. The launch lock assembly comprises first and second mount pieces, a releasable clamp device, and a pair of retracting assemblies. Each retracting assembly comprises a pair of toothed members having interacting toothed surfaces. The releasable clamp device normally maintains the first and second mount pieces in clamped engagement. When the releasable clamp device is actuated, the first and second mount pieces are released from clamped engagement and one toothed member of each retracting assembly moves in an opposite direction relative to the other one toothed member of the other retracting assembly to define an axial gap on each side of the first mount piece.

Evolving Systems and Adaptive Key Component Control

NASA Technical Reports Server (NTRS)

Frost, Susan A.; Balas, Mark J.

2009-01-01

We propose a new framework called Evolving Systems to describe the self-assembly, or autonomous assembly, of actively controlled dynamical subsystems into an Evolved System with a higher purpose. An introduction to Evolving Systems and exploration of the essential topics of the control and stability properties of Evolving Systems is provided. This chapter defines a framework for Evolving Systems, develops theory and control solutions for fundamental characteristics of Evolving Systems, and provides illustrative examples of Evolving Systems and their control with adaptive key component controllers.

Management of surgical instruments with radio frequency identification tags.

PubMed

Kusuda, Kaori; Yamashita, Kazuhiko; Ohnishi, Akiko; Tanaka, Kiyohito; Komino, Masaru; Honda, Hiroshi; Tanaka, Shinichi; Okubo, Takashi; Tripette, Julien; Ohta, Yuji

2016-01-01

To prevent malpractices, medical staff has adopted inventory time-outs and/or checklists. Accurate inventory and maintenance of surgical instruments decreases the risk of operating room miscounting and malfunction. In our previous study, an individual management of surgical instruments was accomplished using Radio Frequency Identification (RFID) tags. The purpose of this paper is to evaluate a new management method of RFID-tagged instruments. The management system of RFID-tagged surgical instruments was used for 27 months in clinical areas. In total, 13 study participants assembled surgical trays in the central sterile supply department. While using the management system, trays were assembled 94 times. During this period, no assembly errors occurred. An instrument malfunction had occurred after the 19th, 56th, and 73 th uses, no malfunction caused by the RFID tags, and usage history had been recorded. Additionally, the time it took to assemble surgical trays was recorded, and the long-term usability of the management system was evaluated. The system could record the number of uses and the defective history of each surgical instrument. In addition, the history of the frequency of instruments being transferred from one tray to another was recorded. The results suggest that our system can be used to manage instruments safely. Additionally, the management system was acquired of the learning effect and the usability on daily maintenance. This finding suggests that the management system examined here ensures surgical instrument and tray assembly quality.

Autonomous Assembly of Modular Structures in Space and on Extraterrestrial Locations

NASA Astrophysics Data System (ADS)

Alhorn, Dean C.

2005-02-01

The new U.S. National Vision for Space Exploration requires many new enabling technologies to accomplish the goals of space commercialization and returning humans to the moon and extraterrestrial environments. Traditionally, flight elements are complete sub-systems requiring humans to complete the integration and assembly. These bulky structures also require the use of heavy launch vehicles to send the units to a desired location. This philosophy necessitates a high degree of safety, numerous space walks at a significant cost. Future space mission costs must be reduced and safety increased to reasonably achieve exploration goals. One proposed concept is the autonomous assembly of space structures. This concept is an affordable, reliable solution to in-space and extraterrestrial assembly. Assembly is autonomously performed when two components join after determining that specifications are correct. Local sensors continue monitor joint integrity post assembly, which is critical for safety and structural reliability. Achieving this concept requires a change in space structure design philosophy and the development of innovative technologies to perform autonomous assembly. Assembly of large space structures will require significant numbers of integrity sensors. Thus simple, low-cost sensors are integral to the success of this concept. This paper addresses these issues and proposes a novel concept for assembling space structures autonomously. Core technologies required to achieve in space assembly are presented. These core technologies are critical to the goal of utilizing space in a cost efficient and safe manner. Additionally, these novel technologies can be applied to other systems both on earth and extraterrestrial environments.

Fabrication of hierarchical hybrid structures using bio-enabled layer-by-layer self-assembly.

PubMed

Hnilova, Marketa; Karaca, Banu Taktak; Park, James; Jia, Carol; Wilson, Brandon R; Sarikaya, Mehmet; Tamerler, Candan

2012-05-01

Development of versatile and flexible assembly systems for fabrication of functional hybrid nanomaterials with well-defined hierarchical and spatial organization is of a significant importance in practical nanobiotechnology applications. Here we demonstrate a bio-enabled self-assembly technique for fabrication of multi-layered protein and nanometallic assemblies utilizing a modular gold-binding (AuBP1) fusion tag. To accomplish the bottom-up assembly we first genetically fused the AuBP1 peptide sequence to the C'-terminus of maltose-binding protein (MBP) using two different linkers to produce MBP-AuBP1 hetero-functional constructs. Using various spectroscopic techniques, surface plasmon resonance (SPR) and localized surface plasmon resonance (LSPR), we verified the exceptional binding and self-assembly characteristics of AuBP1 peptide. The AuBP1 peptide tag can direct the organization of recombinant MBP protein on various gold surfaces through an efficient control of the organic-inorganic interface at the molecular level. Furthermore using a combination of soft-lithography, self-assembly techniques and advanced AuBP1 peptide tag technology, we produced spatially and hierarchically controlled protein multi-layered assemblies on gold nanoparticle arrays with high molecular packing density and pattering efficiency in simple, reproducible steps. This model system offers layer-by-layer assembly capability based on specific AuBP1 peptide tag and constitutes novel biological routes for biofabrication of various protein arrays, plasmon-active nanometallic assemblies and devices with controlled organization, packing density and architecture. Copyright © 2011 Wiley Periodicals, Inc.

Phototrophic Biofilm Assembly in Microbial-Mat-Derived Unicyanobacterial Consortia: Model Systems for the Study of Autotroph-Heterotroph Interactions

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

Cole, Jessica K.; Hutchison, Janine R.; Renslow, Ryan S.

2014-04-07

Though microbial autotroph-heterotroph interactions influence biogeochemical cycles on a global scale, the diversity and complexity of natural systems and their intractability to in situ environmental manipulation makes elucidation of the principles governing these interactions challenging. Examination of primary succession during phototrophic biofilm assembly provides a robust means by which to elucidate the dynamics of such interactions and determine their influence upon recruitment and maintenance of phylogenetic and functional diversity in microbial communities. We isolated and characterized two unicyanobacterial consortia from the Hot Lake phototrophic mat, quantifying the structural and community composition of their assembling biofilms. The same heterotrophs were retainedmore » in both consortia and included members of Alphaproteobacteria, Gammaproteobacteria, and Bacteroidetes, taxa frequently reported as consorts of microbial photoautotrophs. Cyanobacteria led biofilm assembly, eventually giving way to a late heterotrophic bloom. The consortial biofilms exhibited similar patterns of assembly, with the relative abundances of members of Bacteroidetes and Alphaproteobacteria increasing and members of Gammaproteobacteria decreasing as colonization progressed. Despite similar trends in assembly at higher taxa, the consortia exhibited substantial differences in community structure at the species level. These similar patterns of assembly with divergent community structures suggest that, while similar niches are created by the metabolism of the cyanobacteria, the resultant webs of autotroph-heterotroph and heterotroph-heterotroph interactions driving metabolic exchange are specific to each primary producer. Altogether, our data support these Hot Lake unicyanobacterial consortia as generalizable model systems whose simplicity and tractability permit the deciphering of community assembly principles relevant to natural microbial communities.« less

Ultrarapid Inductive Rewarming of Vitrified Biomaterials with Thin Metal Forms.

PubMed

Manuchehrabadi, Navid; Shi, Meng; Roy, Priyatanu; Han, Zonghu; Qiu, Jinbin; Xu, Feng; Lu, Tian Jian; Bischof, John

2018-06-19

Arteries with 1-mm thick walls can be successfully vitrified by loading cryoprotective agents (CPAs) such as VS55 (8.4 M) or less concentrated DP6 (6 M) and cooling at or beyond their critical cooling rates of 2.5 and 40 °C/min, respectively. Successful warming from this vitrified state, however, can be challenging. For example, convective warming by simple warm-bath immersion achieves 70 °C/min, which is faster than VS55's critical warming rate of 55 °C/min, but remains far below that of DP6 (185 °C/min). Here we present a new method that can dramatically increase the warming rates within either a solution or tissue by inductively warming commercially available metal components placed within solutions or in proximity to tissues with non-invasive radiofrequency fields (360 kHz, 20 kA/m). Directly measured warming rates within solutions exceeded 1000 °C/min with specific absorption rates (W/g) of 100, 450 and 1000 for copper foam, aluminum foil, and nitinol mesh, respectively. As proof of principle, a carotid artery diffusively loaded with VS55 and DP6 CPA was successfully warmed with high viability using aluminum foil, while standard convection failed for the DP6 loaded tissue. Modeling suggests this approach can improve warming in tissues up to 4-mm thick where diffusive loading of CPA may be incomplete. Finally, this technology is not dependent on the size of the system and should therefore scale up where convection cannot.

Investigation into the High Voltage Shutdown of the Oxygen Generator System in the International Space Station

NASA Technical Reports Server (NTRS)

Carpenter, Joyce E.; Gentry, Gregory J.; Diderich, Greg S.; Roy, Robert J.; Golden, John L.; VanKeuren, Steve; Steele, John W.; Rector, Tony J.; Varsik, Jerome D.; Montefusco, Daniel J.;

Applications of Optical Fiber Assemblies in Harsh Environments, the Journey Past, Present and Future

NASA Technical Reports Server (NTRS)

Ott, Melanie N.; LaRocca, Frank; Thomas, William Joe; Switzer, Robert; Chuska, Richard; Macmurphy, Shawn

2008-01-01

Over the past ten years, NASA has studied the effects of harsh environments on optical fiber assemblies for communication systems, lidar systems, and science missions. The culmination of this has resulted in recent technologies that are unique and tailored to meeting difficult requirements under challenging performance constraints. This presentation will focus on the past mission applications of optical fiber assemblies including; qualification information, lessons learned and new technological advances that will enable the road ahead.

Orbital assembly and maintenance study. Executive summary. [space erectable structures/structural design criteria

NASA Technical Reports Server (NTRS)

Gorman, D.; Grant, C.; Kyrias, G.; Lord, C.; Rombach, J. P.; Salis, M.; Skidmore, R.; Thomas, R.

1975-01-01

A sound, practical approach for the assembly and maintenance of very large structures in space is presented. The methods and approaches for assembling two large structures are examined. The maintenance objectives include the investigation of methods to maintain five geosynchronous satellites. The two assembly examples are a 200-meter-diameter radio astronomy telescope and a 1,000-meter-diameter microwave power transmission system. The radio astronomy telescope operates at an 8,000-mile altitude and receives RF signals from space. The microwave power transmission system is part of a solar power satellite that will be used to transmit converted solar energy to microwave ground receivers. Illustrations are included.

Modeling Effects of RNA on Capsid Assembly Pathways via Coarse-Grained Stochastic Simulation

PubMed Central

Smith, Gregory R.; Xie, Lu; Schwartz, Russell

2016-01-01

The environment of a living cell is vastly different from that of an in vitro reaction system, an issue that presents great challenges to the use of in vitro models, or computer simulations based on them, for understanding biochemistry in vivo. Virus capsids make an excellent model system for such questions because they typically have few distinct components, making them amenable to in vitro and modeling studies, yet their assembly can involve complex networks of possible reactions that cannot be resolved in detail by any current experimental technology. We previously fit kinetic simulation parameters to bulk in vitro assembly data to yield a close match between simulated and real data, and then used the simulations to study features of assembly that cannot be monitored experimentally. The present work seeks to project how assembly in these simulations fit to in vitro data would be altered by computationally adding features of the cellular environment to the system, specifically the presence of nucleic acid about which many capsids assemble. The major challenge of such work is computational: simulating fine-scale assembly pathways on the scale and in the parameter domains of real viruses is far too computationally costly to allow for explicit models of nucleic acid interaction. We bypass that limitation by applying analytical models of nucleic acid effects to adjust kinetic rate parameters learned from in vitro data to see how these adjustments, singly or in combination, might affect fine-scale assembly progress. The resulting simulations exhibit surprising behavioral complexity, with distinct effects often acting synergistically to drive efficient assembly and alter pathways relative to the in vitro model. The work demonstrates how computer simulations can help us understand how assembly might differ between the in vitro and in vivo environments and what features of the cellular environment account for these differences. PMID:27244559

78 FR 27951 - Foreign-Trade Zone (FTZ) 75-Phoenix, Arizona; Notification of Proposed Production Activity...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-13

... systems; duct temperature limiters; air/oil heat exchangers; oil cooler fans; fuel filter assemblies... assemblies; filter extractors; de- coupler/disassembly wrenches; torque wrench adaptors; test benches; drills...; filter assemblies; oil filter install kits; cartridge screens; filter housings; trim balance weights...

Alterations in Peptidoglycan Cross-Linking Suppress the Secretin Assembly Defect Caused by Mutation of GspA in the Type II Secretion System.

PubMed

Vanderlinde, Elizabeth M; Strozen, Timothy G; Hernández, Sara B; Cava, Felipe; Howard, S Peter

2017-04-15

In Gram-negative bacteria, the peptidoglycan (PG) cell wall is a significant structural barrier for outer membrane protein assembly. In Aeromonas hydrophila , outer membrane multimerization of the type II secretion system (T2SS) secretin ExeD requires the function of the inner membrane assembly factor complex ExeAB. The putative mechanism of the complex involves the reorganization of PG and localization of ExeD, whereby ExeA functions by interacting with PG to form a site for secretin assembly and ExeB forms an interaction with ExeD. This mechanism led us to hypothesize that increasing the pore size of PG would circumvent the requirement for ExeA in the assembly of the ExeD secretin. Growth of A. hydrophila in 270 mM Gly reduced PG cross-links by approximately 30% and led to the suppression of secretin assembly defects in exeA strains and in those expressing ExeA mutants by enabling localization of the secretin in the outer membrane. We also established a heterologous ExeD assembly system in Escherichia coli and showed that ExeAB and ExeC are the only A. hydrophila proteins required for the assembly of the ExeD secretin in E. coli and that ExeAB-independent assembly of ExeD can occur upon overexpression of the d,d-carboxypeptidase PBP 5. These results support an assembly model in which, upon binding to PG, ExeA induces multimerization and pore formation in the sacculus, which enables ExeD monomers to interact with ExeB and assemble into a secretin that both is inserted in the outer membrane and crosses the PG layer to interact with the inner membrane platform of the T2SS. IMPORTANCE The PG layer imposes a strict structural impediment for the assembly of macromolecular structures that span the cell envelope and serve as virulence factors in Gram-negative species. This work revealed that by decreasing PG cross-linking by growth in Gly, the absolute requirement for the PG-binding activity of ExeA in the assembly of the ExeD secretin was alleviated in A. hydrophila In a heterologous assembly model in E. coli , expression of the carboxypeptidase PBP 5 could relieve the requirement for ExeAB in the assembly of the ExeD secretin. These results provide some mechanistic details of the ExeAB assembly complex function, in which the PG-binding and oligomerization functions of ExeAB are used to create a pore in the PG that is required for secretin assembly. Copyright © 2017 American Society for Microbiology.

Scarless assembly of unphosphorylated DNA fragments with a simplified DATEL method.

PubMed

Ding, Wenwen; Weng, Huanjiao; Jin, Peng; Du, Guocheng; Chen, Jian; Kang, Zhen

2017-05-04

Efficient assembly of multiple DNA fragments is a pivotal technology for synthetic biology. A scarless and sequence-independent DNA assembly method (DATEL) using thermal exonucleases has been developed recently. Here, we present a simplified DATEL (sDATEL) for efficient assembly of unphosphorylated DNA fragments with low cost. The sDATEL method is only dependent on Taq DNA polymerase and Taq DNA ligase. After optimizing the committed parameters of the reaction system such as pH and the concentration of Mg 2+ and NAD+, the assembly efficiency was increased by 32-fold. To further improve the assembly capacity, the number of thermal cycles was optimized, resulting in successful assembly 4 unphosphorylated DNA fragments with an accuracy of 75%. sDATEL could be a desirable method for routine manual and automated assembly.

Radiation Chemistry in Organized Assemblies.

ERIC Educational Resources Information Center

Thomas, J. K.; Chen, T. S.

1981-01-01

Expands the basic concepts regarding the radiation chemistry of simple aqueous systems to more complex, but well defined, organized assemblies. Discusses the differences in behavior in comparison to simple systems. Reviews these techniques: pulse radiolysis, laser flash, photolysis, and steady state irradiation by gamma rays or light. (CS)

Identification of optimum sequencing depth especially for de novo genome assembly of small genomes using next generation sequencing data.

PubMed

Desai, Aarti; Marwah, Veer Singh; Yadav, Akshay; Jha, Vineet; Dhaygude, Kishor; Bangar, Ujwala; Kulkarni, Vivek; Jere, Abhay

2013-01-01

Next Generation Sequencing (NGS) is a disruptive technology that has found widespread acceptance in the life sciences research community. The high throughput and low cost of sequencing has encouraged researchers to undertake ambitious genomic projects, especially in de novo genome sequencing. Currently, NGS systems generate sequence data as short reads and de novo genome assembly using these short reads is computationally very intensive. Due to lower cost of sequencing and higher throughput, NGS systems now provide the ability to sequence genomes at high depth. However, currently no report is available highlighting the impact of high sequence depth on genome assembly using real data sets and multiple assembly algorithms. Recently, some studies have evaluated the impact of sequence coverage, error rate and average read length on genome assembly using multiple assembly algorithms, however, these evaluations were performed using simulated datasets. One limitation of using simulated datasets is that variables such as error rates, read length and coverage which are known to impact genome assembly are carefully controlled. Hence, this study was undertaken to identify the minimum depth of sequencing required for de novo assembly for different sized genomes using graph based assembly algorithms and real datasets. Illumina reads for E.coli (4.6 MB) S.kudriavzevii (11.18 MB) and C.elegans (100 MB) were assembled using SOAPdenovo, Velvet, ABySS, Meraculous and IDBA-UD. Our analysis shows that 50X is the optimum read depth for assembling these genomes using all assemblers except Meraculous which requires 100X read depth. Moreover, our analysis shows that de novo assembly from 50X read data requires only 6-40 GB RAM depending on the genome size and assembly algorithm used. We believe that this information can be extremely valuable for researchers in designing experiments and multiplexing which will enable optimum utilization of sequencing as well as analysis resources.

A knowledge-based design for assemble system for vehicle seat

NASA Astrophysics Data System (ADS)

Wahidin, L. S.; Tan, CheeFai; Khalil, S. N.; Juffrizal, K.; Nidzamuddin, M. Y.

2015-05-01

Companies worldwide are striving to reduce the costs of their products to impact their bottom line profitability. When it comes to improving profits, there are in two choices: sell more or cut the cost of what is currently being sold. Given the depressed economy of the last several years, the "sell more" option, in many cases, has been taken off the table. As a result, cost cutting is often the most effective path. One of the industrial challenges is to search for the shorten product development and lower manufacturing cost especially in the early stage of designing the product. Knowledge-based system is used to assist the industry when the expert is not available and to keep the expertise within the company. The application of knowledge-based system will enable the standardization and accuracy of the assembly process. For this purpose, a knowledge-based design for assemble system is developed to assist the industry to plan the assembly process of the vehicle seat.

Multi-pose system for geometric measurement of large-scale assembled rotational parts

NASA Astrophysics Data System (ADS)

Deng, Bowen; Wang, Zhaoba; Jin, Yong; Chen, Youxing

2017-05-01

To achieve virtual assembly of large-scale assembled rotational parts based on in-field geometric data, we develop a multi-pose rotative arm measurement system with a gantry and 2D laser sensor (RAMSGL) to measure and provide the geometry of these parts. We mount a 2D laser sensor onto the end of a six-jointed rotative arm to guarantee the accuracy and efficiency, combine the rotative arm with a gantry to measure pairs of assembled rotational parts. By establishing and using the D-H model of the system, the 2D laser data is turned into point clouds and finally geometry is calculated. In addition, we design three experiments to evaluate the performance of the system. Experimental results show that the system’s max length measuring deviation using gauge blocks is 35 µm, max length measuring deviation using ball plates is 50 µm, max single-point repeatability error is 25 µm, and measurement scope is from a radius of 0 mm to 500 mm.

Fuel-Mediated Transient Clustering of Colloidal Building Blocks.

PubMed

van Ravensteijn, Bas G P; Hendriksen, Wouter E; Eelkema, Rienk; van Esch, Jan H; Kegel, Willem K

2017-07-26

Fuel-driven assembly operates under the continuous influx of energy and results in superstructures that exist out of equilibrium. Such dissipative processes provide a route toward structures and transient behavior unreachable by conventional equilibrium self-assembly. Although perfected in biological systems like microtubules, this class of assembly is only sparsely used in synthetic or colloidal analogues. Here, we present a novel colloidal system that shows transient clustering driven by a chemical fuel. Addition of fuel causes an increase in hydrophobicity of the building blocks by actively removing surface charges, thereby driving their aggregation. Depletion of fuel causes reappearance of the charged moieties and leads to disassembly of the formed clusters. This reassures that the system returns to its initial, equilibrium state. By taking advantage of the cyclic nature of our system, we show that clustering can be induced several times by simple injection of new fuel. The fuel-mediated assembly of colloidal building blocks presented here opens new avenues to the complex landscape of nonequilibrium colloidal structures, guided by biological design principles.

Distinct Mechanisms for Synchronization and Temporal Patterning of Odor-Encoding Neural Assemblies

NASA Astrophysics Data System (ADS)

MacLeod, Katrina; Laurent, Gilles

1996-11-01

Stimulus-evoked oscillatory synchronization of neural assemblies and temporal patterns of neuronal activity have been observed in many sensory systems, such as the visual and auditory cortices of mammals or the olfactory system of insects. In the locust olfactory system, single odor puffs cause the immediate formation of odor-specific neural assemblies, defined both by their transient synchronized firing and their progressive transformation over the course of a response. The application of an antagonist of ionotropic γ-aminobutyric acid (GABA) receptors to the first olfactory relay neuropil selectively blocked the fast inhibitory synapse between local and projection neurons. This manipulation abolished the synchronization of the odor-coding neural ensembles but did not affect each neuron's temporal response patterns to odors, even when these patterns contained periods of inhibition. Fast GABA-mediated inhibition, therefore, appears to underlie neuronal synchronization but not response tuning in this olfactory system. The selective desynchronization of stimulus-evoked oscillating neural assemblies in vivo is now possible, enabling direct functional tests of their significance for sensation and perception.

Projection optics box

DOEpatents

Hale, Layton C.; Malsbury, Terry; Hudyma, Russell M.; Parker, John M.

2000-01-01

A projection optics box or assembly for use in an optical assembly, such as in an extreme ultraviolet lithography (EUVL) system using 10-14 nm soft x-ray photons. The projection optics box utilizes a plurality of highly reflective optics or mirrors, each mounted on a precision actuator, and which reflects an optical image, such as from a mask, in the EUVL system onto a point of use, such as a target or silicon wafer, the mask, for example, receiving an optical signal from a source assembly, such as a developed from laser system, via a series of highly reflective mirrors of the EUVL system. The plurality of highly reflective optics or mirrors are mounted in a housing assembly comprised of a series of bulkheads having wall members secured together to form a unit construction of maximum rigidity. Due to the precision actuators, the mirrors must be positioned precisely and remotely in tip, tilt, and piston (three degrees of freedom), while also providing exact constraint.

The Self-Assembly of Particles with Multipolar Interactions

DTIC Science & Technology

2004-01-01

the LATEX template in which this thesis has been written. I also thank Kevin Van Workum and Jack Douglas for contributing simulation work and some...of the computational expense of simulating such complex self-assembly systems at the molecular level and a desire to understand the self-assembly at...Dissertation directed by: Professor Wolfgang Losert Department of Physics In this thesis , we describe results from investigations of the self-assembly of

Nanosystem self-assembly pathways discovered via all-atom multiscale analysis.

PubMed

Pankavich, Stephen D; Ortoleva, Peter J

2012-07-26

We consider the self-assembly of composite structures from a group of nanocomponents, each consisting of particles within an N-atom system. Self-assembly pathways and rates for nanocomposites are derived via a multiscale analysis of the classical Liouville equation. From a reduced statistical framework, rigorous stochastic equations for population levels of beginning, intermediate, and final aggregates are also derived. It is shown that the definition of an assembly type is a self-consistency criterion that must strike a balance between precision and the need for population levels to be slowly varying relative to the time scale of atomic motion. The deductive multiscale approach is complemented by a qualitative notion of multicomponent association and the ensemble of exact atomic-level configurations consistent with them. In processes such as viral self-assembly from proteins and RNA or DNA, there are many possible intermediates, so that it is usually difficult to predict the most efficient assembly pathway. However, in the current study, rates of assembly of each possible intermediate can be predicted. This avoids the need, as in a phenomenological approach, for recalibration with each new application. The method accounts for the feedback across scales in space and time that is fundamental to nanosystem self-assembly. The theory has applications to bionanostructures, geomaterials, engineered composites, and nanocapsule therapeutic delivery systems.

Using Hyperspectral Remote Sensing Models to Determine Phytoplankton Density in the Coastal Waters of Long Bay, South Carolina

NASA Astrophysics Data System (ADS)

Harrington, J. E.; Ali, K.

2013-12-01

The southeast coastal region is one of the fastest growing regions in the United States and the increasing utilization of open water bodies has led to the deterioration of water quality and aquatic ecology, placing the future of these resources at risk. In coastal zones, a key index that can be used to assess the stress on the environment is the water quality. The shallow nearshore waters of Long Bay, South Carolina (SC) are heavily influenced by multiple biogeochemical constituents or color producing agents (CPAs) such as, phytoplankton, suspend matter, and dissolved organic carbon. The interaction of the various chemical, biological and physical components gives rise to the optical complexity observed in the coastal waters producing turbid waters. Ecological stress on these environments is reflected by the increase in the frequency and severity of Harmful Algal Blooms (HABs), a prime agent of water quality deterioration, including foul odors and tastes, deoxygenation of bottom waters (hypoxia), toxicity, fish kills, and food web alterations. These are of great concern for human health and are detrimental to the marine life. Therefore, efficient monitoring tools are required for early detection and forecasting purposes as well as to understand the state of the conditions and better protect, manage and address the question of how various natural and anthropogenic factors affect the health of these environments. This study assesses the efficiency remote sensing as a potential tool for accurate and timely detection of HABs, as well as for providing high spatial and temporal resolution information regarding the biogeodynamics in coastal water bodies. Existing blue-green and NIR-red based remote sensing algorithms are applied to the reflectance data obtained using ASD spectroradiometer to predict the amount of chlorophyll, an independent of other associated CPAs in the Long Bay waters. The pigment is the primary light harvesting pigment in all phytoplankton and is used as an index for the estimation of phytoplankton density. Efficiency of the algorithms were evaluated through a least squares regression and residual analysis. Results show that for prediction models of chlorophyll a concentrations, the Oc4v4 by Reilly et al (2000), two -band blue-green empirical algorithm yielded coefficients of determination as high as 0.64 with RMSE=0.29μg/l for an aggregated dataset (n=62, P<0.05). The NIR-red -based two-band algorithm by Dekker et al. (1993) and Gitelson et al. (2000) gave the best chlorophyll a prediction model, with R2 =0.79, RMSE=0.19μg/l. The results illustrate the potential of remote sensing in accounting for the chlorophyll a variability in the turbid waters of Long Bay, SC.

Functional Testing of the Space Station Plasma Contactor

NASA Technical Reports Server (NTRS)

Patterson, Michael J.; Hamley, John A.; Sarver-Verhey, Timothy R.; Soulas, George C.

1995-01-01

A plasma contactor system has been baselined for the International Space Station Alpha (ISSA) to control the electrical potentials of surfaces to eliminate/mitigate damaging interactions with the space environment. The system represents a dual-use technology which is a direct outgrowth of the NASA electric propulsion program and, in particular, the technology development effort on ion thruster systems. The plasma contactor subsystems include a hollow cathode assembly, a power electronics unit, and an expellant management unit. Under a pre-flight development program these subsystems are being developed to the level of maturity appropriate for transfer to U.S. industry for final development. Development efforts for the hollow cathode assembly include design selection and refinement, validating its required lifetime, and quantifying the cathode performance and interface specifications. To date, cathode components have demonstrated over 10,000 hours lifetime, and a hollow cathode assembly has demonstrated over 3,000 ignitions. Additionally, preliminary integration testing of a hollow cathode assembly with a breadboard power electronics unit has been completed. This paper discusses test results and the development status of the plasma contactor subsystems for ISSA, and in particular, the hollow cathode assembly.

Novel agrochemical conjugates with self-assembling behaviour.

PubMed

Liu, Qingtao; Graham, Bim; Hawley, Adrian; Dong, Yao-Da; Boyd, Ben J

2018-02-15

That conjugation of agrichemicals to pro-assembly hydrophobic moieties will enable enhanced compatibility and loading with host lyotropic liquid crystalline carrier matrix, and potentially self-assemble in their own right in aqueous environments. A series of lipid-like agrochemical-conjugates were synthesized using specific amphiphilic entities conjugated onto the agrochemicals, picloram and 2,4-dichlorophenoxyacetic acid (2,4-D). The self-assembly behaviour and compatibility of the novel entities when incorporated into phytantriol and monoolein-based liquid crystalline systems were examined using small angle X-ray scattering, cryo-TEM and polarized optical microscopy. Compared to agrochemical-conjugates with simple alkyl ester groups, the esterification of the agrochemicals with amphiphilic groups such as phytantriol and monoolein led to greater structural compatibility and consequently a greater loading of the agrochemicals in the liquid crystalline systems without destabilizing phase structure. Picloram-monoolein and picloram-monoelaidin can self-assemble to form lamellar structures in water. However, certain agrochemical-conjugates such as picloram-monoelaidin and picloram-PEGn-oleate showed poor compatibility with liquid crystalline systems, resulting in phase separation. Copyright © 2017 Elsevier Inc. All rights reserved.

IFT trains in different stages of assembly queue at the ciliary base for consecutive release into the cilium

PubMed Central

Wingfield, Jenna L; Mengoni, Ilaria; Bomberger, Heather; Jiang, Yu-Yang; Walsh, Jonathon D; Brown, Jason M; Picariello, Tyler; Cochran, Deborah A; Zhu, Bing; Pan, Junmin; Eggenschwiler, Jonathan; Gaertig, Jacek; Witman, George B; Kner, Peter; Lechtreck, Karl

2017-01-01

Intraflagellar transport (IFT) trains, multimegadalton assemblies of IFT proteins and motors, traffic proteins in cilia. To study how trains assemble, we employed fluorescence protein-tagged IFT proteins in Chlamydomonas reinhardtii. IFT-A and motor proteins are recruited from the cell body to the basal body pool, assembled into trains, move through the cilium, and disperse back into the cell body. In contrast to this ‘open’ system, IFT-B proteins from retrograde trains reenter the pool and a portion is reused directly in anterograde trains indicating a ‘semi-open’ system. Similar IFT systems were also observed in Tetrahymena thermophila and IMCD3 cells. FRAP analysis indicated that IFT proteins and motors of a given train are sequentially recruited to the basal bodies. IFT dynein and tubulin cargoes are loaded briefly before the trains depart. We conclude that the pool contains IFT trains in multiple stages of assembly queuing for successive release into the cilium upon completion. DOI: http://dx.doi.org/10.7554/eLife.26609.001 PMID:28562242

Molecular Origins of Thermal Transitions in Polyelectrolyte Assemblies

NASA Astrophysics Data System (ADS)

Yildirim, Erol; Zhang, Yanpu; Antila, Hanne S.; Lutkenhaus, Jodie L.; Sammalkorpi, Maria; Aalto Team; Texas A&M Team

2015-03-01

Polyelectrolyte (PE) multilayers and complexes formed from oppositely charged polymers can exhibit extraordinary superhydrophobicity, mechanical strength and responsiveness resulting in applications ranging functional membranes, optics, sensors and drug delivery. Depending on the assembly conditions, PE assemblies may undergo a thermal transition from glassy to soft behavior under heating. Our earlier work using thermal analysis measurements shows a distinct thermal transition for PE layer-by-layer (LbL) systems assembled with added salt but no analogous transition in films assembled without added salt or dry systems. These findings raise interesting questions on the nature of the thermal transition; here, we explore its molecular origins through characterization of the PE aggregates by temperature-controlled all-atom molecular dynamics simulations. We show via molecular simulations the thermal transition results from the existence of an LCST (lower critical solution temperature) in the PE systems: the diffusion behavior, hydrogen bond formation, and bridging capacity of water molecules plasticizing the complex changes at the transition temperature. We quantify the behavior, map its chemistry specificity through comparison of strongly and weakly charged PE complexes, and connect the findings to our interrelated QCM-D experiments.

Pressure activated interconnection of micro transfer printed components

NASA Astrophysics Data System (ADS)

Prevatte, Carl; Guven, Ibrahim; Ghosal, Kanchan; Gomez, David; Moore, Tanya; Bonafede, Salvatore; Raymond, Brook; Trindade, António Jose; Fecioru, Alin; Kneeburg, David; Meitl, Matthew A.; Bower, Christopher A.

2016-05-01

Micro transfer printing and other forms of micro assembly deterministically produce heterogeneously integrated systems of miniaturized components on non-native substrates. Most micro assembled systems include electrical interconnections to the miniaturized components, typically accomplished by metal wires formed on the non-native substrate after the assembly operation. An alternative scheme establishing interconnections during the assembly operation is a cost-effective manufacturing method for producing heterogeneous microsystems, and facilitates the repair of integrated microsystems, such as displays, by ex post facto addition of components to correct defects after system-level tests. This letter describes pressure-concentrating conductor structures formed on silicon (1 0 0) wafers to establish connections to preexisting conductive traces on glass and plastic substrates during micro transfer printing with an elastomer stamp. The pressure concentrators penetrate a polymer layer to form the connection, and reflow of the polymer layer bonds the components securely to the target substrate. The experimental yield of series-connected test systems with >1000 electrical connections demonstrates the suitability of the process for manufacturing, and robustness of the test systems against exposure to thermal shock, damp heat, and mechanical flexure shows reliability of the resulting bonds.

Automation of closed environments in space for human comfort and safety

NASA Technical Reports Server (NTRS)

Cogley, Allen C.; Tucker, Nathan P.

1992-01-01

For prolonged missions into space and colonization outside the Earth's atmosphere, development of Environmental Control and Life Support Systems (ECLSS) are essential to provide astronauts with habitable environments. The Kansas State University Advanced Design Team have researched and designed a control system for an ECLSS like that on Space Station Freedom. The following milestones have been accomplished: (1) completed computer simulation of the CO2 Removal Assembly; (2) created a set of rules for the expert control system of the CO2 Removal Assembly; (3) created a classical controls system for the CO2 Removal Assembly; (4) established a means of communication between the mathematical model and the two controls systems; and (5) analyzed the dynamic response of the simulation and compared the two methods of control.